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TECHNICAL FIELD
[0001] This invention relates to a method for desolvating an alane-etherate complex to create alane.
BACKGROUND
[0002] A key limiting factor in the widespread adoption of proton exchange membrane fuel cell (PEMFC) based power systems is hydrogen fuel storage. The development of a viable hydrogen storage solution will have a profound impact on how consumers will power portable devices, since batteries simply cannot match demands for runtime, energy density and reliability.
[0003] Because hydrogen has poor energy content per volume (0.01 kJ/L at STP and 8.4 MJ/L for liquid hydrogen vs. 32 MJ/L for petroleum), physical transport and storage as a gas or liquid is impractical. Additionally, the compression process to achieve the pressures necessary to reach a high density is energy-intensive and doesn't solve the hazard issue. Also, the densities of compressed H 2 or liquefied H 2 are still below those required to reach practical fuel storage goals.
[0004] Physical means to store hydrogen include sorbents such as carbon nanotubes and foams, zeolites, metal-organic frameworks; and intermetallics such as titanium-manganese alloy 5800, complex hydrides such as metal alanates, amides, and borohydrides, and chemical hydrides such as sodium borohydride/water and ammonia borane (AB). Despite intensive and elegant work on sorbents and complex hydrides, practical systems that can store and release ≧6wt % hydrogen at moderate temperatures are still far from realization.
[0005] Alane is an attractive candidate for solid hydrogen storage and release because it has a density of 1.48 g/cm 3 and releases up to 10 weight percent hydrogen and aluminum in a single step upon heating to ≦200° C. Alane can be formed from the desolvation of labile alane-ligand complexes such as alane-etherate. Alane's formula is sometimes represented with the formula (AlH 3 ) n because it is a polymeric network solid. Alane is formed as numerous polymorphs: the alpha (α), alpha prime (α′), beta (β), delta (δ), epsilon (ε), zeta (ζ), or gamma (γ) polymorphs. Each of the polymorphs has different physical properties and varying stability. The most thermally stable polymorph is α-alane, featuring aluminum atoms surrounded by six hydrogen atoms that bridge to six other aluminum atoms. The Al-H distances are all equivalent and the Al-H-Al angle is approximately 141°. While α-alane's crystals have a cubic or hexagonal morphology, α′-alane forms needlelike crystals and γ-alane forms a bundle of fused needles. Typically, the lightweight, unstable γ-alane is produced first, converting under certain conditions to the more stable rhombohedral β-alane polymorph first, then to α-alane. When trace amounts of water are present during crystallization the δ-alane and ε-alane can be formed. The ζ-alane polymorph is prepared by crystallization from di-n-propyl ether. The α′, δ, ε, and ζ polymorphs do not convert to α-alane upon heating and are less thermally stable than α-alane.
[0006] Crystalline alane has many uses including: hydrogen storage, inorganic and organic synthesis, as an ingredient in propellants and pyrotechnics, as a polymerization catalyst, and as a precursor to aluminum films and coatings. Consequently there has been considerable research carried out on the preparation of alane, since the first report of its preparation in 1942 (Stecher and Wiberg, Ber. 1942, 75, 2003). Finholt, Bond, and Schlesinger reported an improved method of synthesis of alane-diethyl etherate in 1947 which has formed the foundation for most of the reported methods for the synthesis of non-solvated crystalline alane ( J. Am. Chem. Soc., 1947, 69, 1199). The reaction is shown below, and the amount of ether complexed to the alane product depended on the length and temperature of the drying step of the reaction.
[0000] 3LiAlH 4 +AlCl 3 →4AlH 3 +3LiCl.
[0007] Reports describing the preparation and stabilization of non-solvated crystalline alane began to appear in the patent literature in 1974 (Scruggs, U.S. Pat. No. 3,801,657, Roberts et al. U.S. Pat. No. 3,803,082, King, U.S. Pat. No. 3,810,974, Matzek et al. U.S. Pat. No. 3,819,819, Daniels et al. US3819335, Roberts, U.S. Pat. No. 3,821,044, Brower et al. U.S. Pat. No. 3,823,226, Schmidt et al. U.S. Pat. No. 3,840,654, and Self et al. U.S. Pat. No. 3,844,854). Removal of the residual diethyl ether was effected by using higher than stoichiometric ratios of complex aluminum hydride to aluminum chloride, as well as inclusion of lithium borohydride as a “seeding” or “crystallization” agent. Several patents describe the use of sodium aluminum hydride instead of lithium aluminum hydride (Ashby et al. U.S. Pat. No. 3,829,390, and Kraus et al. U.S. Pat. No. 3,857,930). As disclosed in these patents and Brower et al. (“Brower”), “Preparation and Properties of Aluminum Hydride,” J. Am. Chem. Soc., 1976, 98, 2450, alane is usually synthesized by reacting aluminum trichloride (AlCl 3 ) and metal aluminum hydride (MAlH 4 ) in diethyl ether or diethyl ether-hydrocarbon solvent mixtures. The aluminum trichloride was dissolved in diethyl ether at −10° C. A minimum of three mole equivalents of MAlH 4 was added to the aluminum trichloride solution to produce a solvated alane-ether complex and a precipitate of metal chloride (MCl, e.g. LiCl or NaCl). In order to desolvate the alane-ether complex, 0.5 to 4.0 mole equivalents of a borohydride salt, such as lithium borohydride or sodium borohydride, was mixed with the solution including the alane-ether complex. The mixture was filtered and the filtrate was diluted with toluene or benzene to provide an ether to toluene or benzene ratio of 15:85. The mixture was heated to 85° C. to 95° C. to desolvate the alane-ether complex and the diethyl ether was subsequently removed by distillation. The precipitated alane was recovered by aqueous acid quenching, filtration, and washing. Brower also discloses that the reaction is conducted in the absence of water, oxygen, and other reactive species because if water is present, the δ and ε polymorphs are undesirably formed.
[0008] The methods reported for stabilization of the reactive alane product during this time included in situ or subsequent treatment of alane with an alkyl or aryl silicol, coating the alane surface with an organic compound containing at least one phenyl group or a condensed ring structure, and washing the alane product (often with some amount of magnesium included in the preparation step) with an aqueous solution buffered at from about pH 6 to 8.
[0009] However, the large volumes of solvent required as well as the excess aluminohydride and borohydride salts used to desolvate the alane-ether complex make these syntheses of α-alane expensive. The borohydride salts also generate byproducts that require disposal. Furthermore, the alane produced by the method of Brower is typically contaminated with undesirable polymorphs and is prone to decomposition during desolvation.
[0010] Alternatively, as described in French Patent No. FR2245569 (1975), to desolvate and crystallize the α-polymorph, the diethyl ether may be removed from the crystallization solution, such as by distilling the diethyl ether. The distillation can be carried out between 50° and 85° C. At the bottom of this range, between 50° and 65° C., etherate intermediate is formed and is converted into α-alane. However, at the top of this range, between 65° and 85° C., etherate aluminum hydride does not appear and stable α-alane precipitates are formed almost immediately. By keeping the mixture in 8% to 10% of ether after the initial distillation, a final α-alane product may be obtained with superior features. Retention of the ether allows the rearrangement of alane during the conversion to the a form of alane as thermal decomposition of the crystal is reduced and the final product is crystalline.
[0011] As yet another alternative, the solvent may be removed from alane by vacuum drying at temperatures between 30° C. and 90° C. This process may be enhanced when a desolvating species is present such as a complex metal hydride (LiAl 4 , LiBH 4 ) or a metal halide (e.g., LiCl). See, e.g., A. N. Tskhai et al. Rus. J. Inorg. Chem. 37:877 (1992), and U.S. Pat. No. 3,801,657 to Scruggs. The desolvating species can be removed with a solvent that preferentially dissolves the desolvating species over the metal hydride. The desolvating species can also be removed with a solvent that preferentially dissolves the metal hydride over the desolvating species (as disclosed in U.S. Pat. No. 3,453,089 to Guidice). After removal the desolvating species can be recovered for further use.
[0012] Yet another alternative used to remove the diethyl ether involves heating the crystallization solution at ambient or reduced pressure, as described in U.S. Pat. No. 7,238,336 to Lund et al. For instance, if the diethyl ether is removed under vacuum, the crystallization solution may be heated at a temperature ranging from approximately 50° C. to approximately 60° C. However, if the diethyl ether is removed at ambient pressure, a temperature ranging from approximately 80° C. to approximately 100° C., such as from approximately 80° C. to approximately 97° C., may be used. A rate at which the diethyl ether is removed may affect the formation of the α-alane. If the diethyl ether is removed too quickly, the alane-ether complex may precipitate from the crystallization solution rather than forming the crystals of the α-alane. However, if the diethyl ether is removed too slowly, the crystallization process may be too long for practical and economical purposes.
[0013] Thus, as described above, a number of methods of preparing solvated alane complexes are known. In addition, a number of methods for desolvating solvated alane complexes have been described in the literature. However, DOW Chemical Company is the only known company to have carried out the preparation of alane on a commercial scale.
[0014] Given the attractive properties of alane for hydrogen storage, it is perhaps surprising that its use is not more widespread. The reasons for this lie in its challenging synthesis and high reactivity. According to the chemical literature, the most common method of synthesis—the Dow Method—proceeds as shown in Reactions 1 and 2. The challenges in this process lie firstly in the removal, without hydrogen loss, of the diethyl ether solvent (Et 2 O) from the etherate (AlH 3 -nEt 2 O) produced in Reaction 1, to obtain the single α-phase that by nature of its structure has the highest hydrogen density of the seven known polymorphs of AlH 3 . Secondly, the cost of the process is inflated on account of vacuum drying (Reaction 2) and the high cost of the LiAlH 4 precursor.
[0000] 3LiAlH 4 +AlCl 3 −(Et 2 O solvent)→3LiCl+AlH 3 -nEt 2 O Reaction 1
[0000] LiAlH 4 +AlH 3 -nEt 2 O−(65° C., in vacuo)→LiAlH 4 +AlH 3 +Et 2 O Reaction 2
[0015] Current methods for the preparation of alane are expensive because of, among other things, the high cost of desolvation to prepare the stable α-alane crystalline phase. It would be desirable to reproducibly produce a high yield of α-alane using a low-cost method.
[0016] An object of the present invention is to provide an improved low-cost method for the preparation of α-alane suitable for use as a solid hydrogen storage and release material.
SUMMARY
[0017] According to one aspect of the invention, α-alane is produced by a method including the steps: preparing an alane-etherate solution comprising an alane-etherate in a solvent; desolvating the alane-etherate solution by electrospraying in an inert atmosphere; and collecting the α-alane. Embodiments can include one or more of the following features:
the step of desolvating the alane-etherate solution includes forming droplets of the solution by applying a voltage to the solution; the alane-etherate solution includes an alane-etherate complex and a solvent; the solvent can consist essentially of diethyl ether; the electrospraying can be performed at a temperature from greater than 60° C. to less than 140° C.; the electrospraying can be performed at a temperature of at least 65° C.; the electrospraying can be performed at a temperature less than 125° C.; the electrospraying can be performed at a temperature no greater than 100° C. the alane-etherate solution contains 0.25 weight percent to 2 weight percent alane; the alane-etherate solution can contain at least 0.5 weight percent alane; the alane-etherate solution can contain no more than 1.5 weight percent alane; the alane-etherate solution can contain no more than 1.0 weight percent alane; a step of annealing follows the step of desolvating the alane-etherate solution and the step of collecting the α-alane; the step of annealing can be performed at a temperature of from 65° C. to less than 120° C.; the step of annealing can be performed at a temperature of from 65° C. to 100° C. the step of collecting the α-alane immediately follows the step of desolvating the alane-etherate solution; in the step of desolvating the alane etherate solution, the solution is sprayed simultaneously from a plurality of nozzles; the collected α-alane is pelletized; the alane-etherate solution is prepared by reacting at least one metal aluminum hydride with at least one proton-donating compound; the proton-donating compound can be an acid; the acid can be one or any combination of hydrochloric acid, sulfuric acid and methane sulfonic acid; the at least one metal aluminum hydride includes a metal from Group 1 of the Periodic Table of the Elements; the metal from Group 1 of the Periodic Table of the elements can be lithium or sodium; the alane-etherate solution is prepared by reacting at least on alkyl halide with at least one metal aluminum hydride; the at least one alkyl halide can be benzyl chloride or n-butyl bromide; the at least one metal aluminum hydride can include a metal from the Group 1 of the Periodic Table of the Elements; the metal from Group 1 of the Periodic Table of the Elements can be lithium or sodium; and a tertiary amine is added in the step of preparing the alane-etherate solution; the tertiary amine can be a trialkylamine.
[0028] Desolvation of an alane-etherate complex is accomplished by spraying processes such as electospraying and/or electrospinning to provide α-alane with superior purity and properties to conventional desolvation methods. The process for producing alane is superior to existing methods because of the lower amounts of solvents used, lower cost, and higher purity of the alane-etherate complex. These and other advantages of the invention will be further understood and appreciated by those skilled in the art by reference to the following written specification and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] In the drawings:
[0030] FIG. 1 shows an electrospraying assembly schematic;
[0031] FIG. 2 shows TGA results for the electrospraying of 1 weight percent alane-etherate solutions compared to a conventional vacuum drying method;
[0032] FIG. 3 shows SEM photos comparing the alane produced by electrospraying to conventionally-dried alane-etherate; and
[0033] FIG. 4 is a schematic drawing illustrating the concept of an electrospraying process to produce AlH 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] The embodiments of the present inventions described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of the present inventions.
[0035] All publications and patents mentioned herein are incorporated herein by reference in their respective entireties for the purpose of describing and disclosing, for example, the constructs and methodologies that are described in the publications which might be used in connection with the presently described invention. The publications discussed above and throughout the text are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the inventor is not entitled to antedate such disclosure by virtue of prior invention.
[0036] For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented in the figures. However, it is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific parts, devices and processes illustrated and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.
[0037] The methods referred herein include:
Nuclear Magnetic Resonance, NMR; a probe of the local chemical environment of atoms. Used in this case to explore the local symmetry and connectivity of aluminium atoms and hence deduce the presence of alane, alane-etherate, alumina (Al 2 O 3 ) and the alanate ion (AlH 4 − ). The different atomic environments are identified by the characteristic chemical shift that they produce. Powder X-ray Diffraction, XRD; a method of investigating the long-range or crystalline structure of materials. This is the most direct way to determine the phase of alane that has been produced. Thermo gravimetric analysis, TGA; allows the mass change of the sample to be monitored under controlled heating conditions. This can be used to monitor the amount of ether (Et 2 O) (the value of n) in AlH 3 -nEt 2 O, as well as assessing the amount of hydrogen produced and the nature of any impurities. Thermo-gravimetric analysis with mass spectroscopy, TGA-MS; (also known as IGA) is the same as TGA, but allows the gas released from the sample to be analysed and the identity of certain gases, in this case hydrogen, to be detected by mass spectrometry. Scanning Electron Microscopy, SEM; is used to image materials at the nanometre scale. In contrast to optical microscopes that only permit materials to be visualised on the micrometre scale, this technique gives more information about the materials at a scale close to their atomic or molecular dimensions.
[0043] As used herein, “alane” refers to AlH 3 and can include combinations of the different alane polymorphs. In contrast, when referring to a specific polymorph of alane, the designation of the specific polymorph is used, such as “α-alane.”
[0044] The alane used in the invention can have any acceptable purity level. Preferably for fuel cell applications, the alane is free of organic contaminants. For example, the alane is preferably non-adducted and non-solvated by organic species. The hydrogen storage compositions of the present invention can also have a number of applications other than fuel cells. For some of these other applications, e.g., as catalysts, chemical reactants, propellant, and so on, the alane may contain organic species.
[0045] The alane can be completely composed (i.e., 100% by weight) of any of the alane compositions described above. Alternatively, the alane can include another compound or material which is not an alane polymorph.
[0046] The alane composition is capable of efficiently and controllably producing hydrogen for a sustained period of time. For example, for fuel cell applications, it would be particularly preferred for the alane composition to be capable of releasing adequate levels of hydrogen at a steady rate for a period of several hours or days. For applications where hydrogen demand varies with time, it is possible and preferable to vary the hydrogen desorption rate by varying the temperature.
Alane-Etherate Complex
[0047] The alane-etherate complex can be made by creating alane diethyl etherate using acids in diethyl ether. A solution or a suspension of metal tetrahydroaluminate in diethyl ether is reacted with up to a stoichiometric amount of a suitable acid, as shown in equation (1) below. Suitable acids include sulfuric acid, hydrochloric acid, methanesulfonic acid, and the like. After filtration of the precipitated metal salts, a clear solution of alane-etherate is produced. This solution is stable for several days at lower temperature (e.g., 3° C.) and in the absence of light. When sodium tetrahydroaluminate is used, it is preferred to include up to a stoichiometric amount of a solubilizing agent such as LiCl (X═CO, as shown in equation (2).
[0000]
[0048] Alane-etherate can also be formed upon reduction of an alkyl halide with a metal alanate in a suitable solvent that contains ether, as shown below. It is preferred that the solvent be 100% diethyl ether; however mixtures of toluene and diethyl ether can be used. The alkyl halide can be any suitable alkyl halide such a 1-bromobutane or benzyl chloride. The stoichiometry of the reaction can be varied such that either the alkyl halide or the metal aluminum hydride can be used in excess. Optionally, when using sodium aluminum hydrides it is desirable to include a soluble Li + species to increase the rate of the reaction.
[0000]
[0049] The formation of an alane-tertiary amine adduct, and other alane-solvent complexes can result when using a tertiary amine as part of the reaction. Removal of the solvent and/or the tertiary amine can be carried out using standard protocols. Examples of the reaction processes are shown below. However, any metal alanate (including those disclosed below (Li and Na), others not expressly disclosed herein, or combinations thereof), alkyl halide (including those disclosed herein (benzyl chloride and n-butyl bromide), others not expressly disclosed herein, or combinations thereof), or tertiary amine (including those disclosed below (trialkylamine), others not expressly disclosed herein, or combinations thereof) may be used.
[0000]
[0050] Removal of the tertiary amine can be accomplished by thermally decomposing the tertiary amine-alane adduct in the presence of a catalytic amount of a Group 1 or Group 2 metal hydride or organometallic catalyst as described in U.S. Pat. No. 3,764,666 to Murib, forming alane and the corresponding tertiary amine. As used herein, group designations of the Periodic Table of the Elements are according to the IUPAC (International Union of Pure and Applied Chemistry) Nomenclature of Inorganic Chemistry, Recommendation 2005, in which Group 1 includes the alkali metals, Group 2 includes the alkaline earth metals, Group 3 is the scandium group of transition metals, and so on. The reaction proceeds according to the equation:
[0000]
[0000] where R 1 , R 2 , and R 3 are organic radicals, n 1 and n 2 are integers equal to one or more. The process is carried out at a temperature above the decomposition temperature of the tertiary amine-alane adduct to form alane and the corresponding tertiary amine, but below the decomposition temperature of alane. It is preferred that the temperature be less than 90° C., for example, in the range of 35° C. to about 90° C. At temperatures below 35° C., the rate of decomposition is extremely slow, but the process can still be carried out at lower temperatures if speed is not a disadvantage. To prevent hydrolysis of the alane, the reaction mixture should be anhydrous, and the system should be oxygen-free, such as under nitrogen or other inert gas.
[0051] To assist in driving the decomposition reaction to completion, at least one of the products should be removed from the reaction mixture, preferably as it is formed. The tertiary amine can be removed from the reaction zone by distillation, desirably under reduced pressure, so as to keep the reaction mixture at below 90° C. The amine also can be removed by sweeping with inert diluent or solvent vapors, or with an inert gas, such as nitrogen. A reduced pressure, if used, is not so low that the tertiary amine-alane adduct is volatilized at the temperature at which the reaction is carried out. Generally, pressures of from about 10 −8 up to about 50 mm of Hg are satisfactory. Reaction is complete when evolution of tertiary amine ceases.
Electrospraying
[0052] Electrospraying employs electricity to disperse a liquid, usually resulting in a fine aerosol. High voltage is applied to a liquid supplied through an emitter (usually a glass or metallic capillary). Ideally the liquid reaching the emitter tip forms a Taylor cone, which emits a liquid jet through its apex. Varicose waves on the surface of the jet lead to the formation of small and highly charged liquid droplets, which are radially dispersed due to Coulomb repulsion. Electrospraying does not involve the use of polymers, so the jet emerging from the Taylor cone forms micro- or nano-scale droplets that dry rapidly, producing a coating of fine particles on the collector.
[0053] Similarly to the standard electrospraying, the application of high voltage to a polymer solution can result in the formation of a cone-jet geometry. If the jet turns into very fine fibers instead of breaking into small droplets, the process is known as electrospinning. Electrospinning uses an electrical charge to draw micro- or nano-scale fibers from a liquid. Typically this involves pumping or dripping a polymer solution through a nozzle maintained at a high relative potential. The drops of solution become charged and electrostatic forces counteract the surface tension, at a critical point a jet of liquid is produced from the Taylor cone. As the jet travels through the atmosphere, the solvent evaporates, so when the jet reaches the collector plate it has formed dry polymer fibers. The electrospinning process can be further subdivided into single-phase or coaxial spinning; single-phase uses a single polymer solution in a relatively simple process, while the more complex co-axial spinning uses two solutions pumped through concentric needles, allowing finer control over material properties.
[0054] Both of these electro-hydrodynamic processes are controlled and affected by a wide variety parameters. The parameters include: solution parameters (such as viscosity/rheometry, surface tension, vapour pressure, conductivity, and dielectric constant); environmental parameters (such as temperature, and humidity/atmosphere); and process parameters (voltage, nozzle geometry, flow rates, and nozzle and plate separation).
[0055] There are a number of different spinning or spraying configurations that may be used, these include: 1) vertical (where the needle points downwards and material is collected on a flat plate); 2) horizontal (where the needle is horizontal and material is collected on a vertical plate); 3) spinning collector (where the material is collected on a spinning drum); and 4) multinozzle (where solution is pumped simultaneously through multiple nozzles housed in a discrete unit). These units may be joined to many other units to provide a scalable technology.
[0056] A stable spraying/spinning process is one where a Taylor cone forms consistently and shows little deviation during the process. The importance of this is: 1) to provide consistent fibers/beads/particles; and 2) to produce a scalable process.
[0057] Electrospraying can be used to reduce the amount of solvent in an alane-etherate solution. This is due to rapid evaporation occurring from the small particles produced during electrospraying. Electrospraying also removes more solvent than vacuum drying alone, and can potentially eliminate a vacuuming drying step in the process of alane production. Electrospraying also results in a more consistent particle size and morphology as described below.
[0058] Generation of alane solutions requires manipulation of air-sensitive materials. Initial handling can be performed using a glove box, while a Schlenk line can be employed in subsequent solution generation. The glove box provides a contained inert atmosphere, it uses a gas circulating system with catalysts and adsorbents to remove trace amounts of oxygen and water from the inert atmosphere such that these contaminants are maintained at concentrations below 10 ppm. The Schlenk line consists of a double manifold, one containing a flowing inert gas and the other connected to a vacuum. These sections can be selectively accessed using a three-way valve that is connected via a rubber tube to the sample vessel.
[0059] Solutions produced using the Schlenk line can be transferred to the spraying rig, which also needs to operate under an inert atmosphere, such as a simple system of flowing nitrogen gas. Alternatively, the inert atmosphere can include circulating nitrogen through catalysts that remove solvents, oxygen and water from the gas stream.
[0060] A crystallization additive may be added to the alane-etherate solution to help form the α-alane crystals. The crystallization additive may promote growth of the a polymorph by providing a nucleation site for the a polymorph. The crystallization additive may also suppress formation of the undesirable polymorphs. It is also believed that early precipitation of the crystals may promote the growth of the a polymorph. Seed crystals of α-alane may be added during the crystallization to promote the growth of the α-alane. The seed crystals may subsequently be incorporated into the α-alane. The crystallization additive may also be an aprotic, electron-rich material. For instance, the crystallization additive may be an olefin, a polyolefin, an anisole, a polydimethyl siloxane, a tertiary amine, an aliphatic or aromatic ether, or mixtures thereof. The olefin may include, but is not limited to, squalene, cyclododecatriene, norbornylene, norbornadiene, a phenyl terminated polybutadiene, and mixtures thereof The anisole may include, but is not limited to, 2,4-dimethyl anisole, 3,5-dimethyl anisole, 2,6-dimethyl anisole, and mixtures thereof These compounds are commercially available from various manufacturers, such as from Sigma-Aldrich Co. (St. Louis, Mo.). The crystallization additive may also be polydimethyl siloxane or LiAlH 4 . The crystallization additive may also be a combination of any of the additives.
[0061] The electrospraying process can be carried out at an elevated temperature (solution temperature and/or spray chamber temperature) to increase solvent removal. For example, a temperature of greater than 60° C. can be used, preferably at least 65° C. At lower temperatures solvent removal will not be as efficient, and the alane produced may not have the desired characteristics (e.g., morphology and particle size). To minimize the release of hydrogen gas from the alane, the temperature should be less than 140° C., preferably less than 120° C., and more preferably no greater than 100° C. The collected alane can be heated (annealed), during collection (e.g., by heating the collection plate) or afterwards, to remove remaining solvent and/or to achieve the desired alane morphology (α-alane). This temperature is preferably at least 65° C. and less than 120° C., more preferably no greater than 100° C. to prevent or minimize the release of hydrogen gas.
[0062] Examples have been set forth below for the purpose of illustration and to describe the best mode of the invention at the present time. However, the scope of this invention is not to be in any way limited by the examples set forth herein.
EXAMPLE 1
Preparation of Alane-Etherate using Lithium Aluminum Hydride and Hydrochloric Acid
[0063] Lithium aluminum hydride (0.76 g, 20 mmol) was weighed into a 100 mL round-bottom flask containing a magnetic stirring bar in a glovebox under Ar atmosphere. The flask was sealed with a rubber septa and put under Ar on a Schlenk line. Anhydrous diethyl ether (22 mL) was added. The septum was replaced quickly with a pressure-equalizing addition funnel that was purged with Ar. A solution of 1M HCl in diethyl ether (16 mL, 16 mmol) was added dropwise over 30 minutes while stirring the reaction mixture in an ice-water bath. After addition of the acid was complete, the reaction mixture was allowed to warm to room temperature with stirring until hydrogen evolution ceased. The slurry was then filtered using a filter cannula, and the insoluble material was washed once with fresh diethyl ether (10 mL total). The combined filtrate had 1 weight percent of AlH 3 .
EXAMPLE 2
Preparation of Alane-Etherate using Lithium Aluminum Hydride and Sulfuric Acid
[0064] A commercial solution of lithium aluminum hydride in diethyl ether (1 M, 37.5 mL, 37.5 mmol) was added to a 100 mL round-bottom flask containing a magnetic stiffing bar under Ar atmosphere. Anhydrous diethyl ether (122.5 mL) was added, and the mixture was cooled in an ice-water bath with stirring under Ar. Concentrated sulfuric acid (reagent grade, 95-98 percent, 1.60 mL, 30 mmol) was added to this solution dropwise via syringe. After addition of the acid was complete, the reaction mixture was allowed to warm to room temperature with stirring until hydrogen evolution ceased. The slurry was then filtered using a filter cannula, and the insoluble material was washed once with fresh diethyl ether (20 mL). The combined filtrate had 0.5 weight percent of AlH 3 .
EXAMPLE 3
Preparation of Alane-Etherate using Sodium Aluminum Hydride, Lithium Chloride and Hydrochloric Acid
[0065] Sodium aluminum hydride (1.35 g, 25 mmol) and lithium chloride (0.848 g, 20 mmol) are combined in a 100 mL round-bottom flask containing a magnetic stirring bar in a glovebox under Ar atmosphere. The flask is sealed with a rubber septa and put under Ar on a Schlenk line. Anhydrous diethyl ether (30 mL) is added. The septum is replaced quickly with a condenser that is being purged with Ar. This slurry is stirred at reflux for three hours under Ar atmosphere, then cooled to 0° C. using an ice-water bath. The condenser is replaced quickly with a pressure-equalizing addition funnel that is being purged with Ar. A solution of 1 M HCl in diethyl ether (20 mL, 20 mmol) is added to the addition funnel using a syringe, then added dropwise to the reaction mixture over 30 minutes while stirring in an ice-water bath. After addition of the acid is complete, the reaction mixture is allowed to warm to room temperature with stirring until hydrogen evolution ceased. The slurry is then filtered using a filter cannula, and the insoluble material is washed once with fresh diethyl ether (10 mL). The combined filtrate containing alane-etherate in ether solution (ca. 1 weight percent AlH 3 ) can be used directly in the electrospraying process.
EXAMPLE 4
Preparation of Alane-Etherate using Benzyl Chloride and Lithium Aluminum Hydride
[0066] Anhydrous diethyl ether (15 mL) is added to a dry 100 mL single neck round bottom flask equipped with a magnetic stir bar and reflux condenser under Ar atmosphere. A solution of lithium aluminum hydride in diethyl ether (1 M, 1185 mL, 1185 mmol) is added via syringe with stiffing under Ar. Neat benzyl chloride (0.91 mL, 7.90 mmol) is then added via syringe and the reaction mixture is warmed to reflux and stirred overnight under Ar. GC/MS analysis of an aliquot taken from the reaction mixture indicates when the conversion of benzyl chloride to toluene is complete. After cooling to room temperature, the reaction slurry is filtered under Ar, providing a 0.33 M solution of alane-etherate in diethyl ether solution.
EXAMPLE 5
Preparation of Alane-Etherate using Benzyl Chloride and a Mixture of Sodium Aluminum Hydride and Lithium Aluminum Hydride
[0067] Sodium aluminum hydride (0.427 g, 7.90 mmol) is added to a dry 100 mL single neck round bottom flask equipped with a magnetic stir bar, sealed with a rubber septum, and put under Ar atmosphere. Anhydrous diethyl ether (25 mL) is added to this flask using a syringe, and the septum is then quickly replaced by a reflux condenser under flow of Ar. A solution of lithium aluminum hydride in diethyl ether (1 M, 1.98 mL s, 1.98 mmol) is added via syringe with stirring under Ar, followed by neat benzyl chloride (0.91 mL, 7.90 mmol). The reaction mixture is warmed to reflux and stirred overnight under Ar. GC/MS analysis of an aliquot taken from the reaction mixture would show that the conversion of benzyl chloride to toluene is complete. After cooling to room temperature, the reaction slurry is filtered under Ar, providing a 0.33 M solution of alane-etherate containing 0.25 eq of lithium aluminum hydride in diethyl ether solution.
EXAMPLE 6
Electrospraying of Alane-Ether Solutions
[0068] An electrospraying apparatus as shown in FIG. 1 was assembled in an inert-atmosphere water-free glovebox. The apparatus 10 included a nozzle 12 through which an alane-etherate solution (alane in diethyl ether) was sprayed. A high voltage direct current power supply 14 was connected to the nozzle 12 . The charged liquid spray included a straight jet 20 and a plume 22 of droplets, and material was collected on a collection plate 16 . The process parameters, such as temperature, applied voltages, nozzle geometry, solution flow rate, the distance between nozzle and collection plate, and direction of spraying can be adjusted to control the amount of solvent removed and the particle size distribution and morphology of the alane produced, as well as to prevent or eliminate the release of hydrogen gas from the alane during the process.
[0069] The electrosprayed alane can be annealed by controlling the ambient temperature of the spraying chamber, or by heating the collecting plate to the desired temperature. The TGA results for electrospraying of a 1 weight percent solution of alane in diethyl ether are shown in FIG. 2 and compared to the same solution dried using conventional methods. In FIG. 2 , the annealing temperature in degrees Celsius is shown on the x-axis and the fractional mass loss on the y-axis. Line 32 shows conventionally dried solution, and lines 34 , 36 and 38 show electrosprayed solution, with the spraying done vertically (as in FIG. 1 ) in line 34 and horizontally in each of lines 36 and 38 . This data shows a significantly greater reduction in residual ether using the electrospray process (to about 83 weight percent) compared to conventional drying. The majority of the ether was removed at annealing temperatures from about 60° C. to 100° C. Hydrogen gas was evolved beginning at about 120° C.
[0070] NMR testing was done on material collected on the collection plate. The 27 Al-NMR results showed only the presence of residual LiAlH 4 and alane-etherate. TGA testing was performed on electrosprayed alane-etherate that was annealed at 65° C. The results showed pure hydrogen was released. The onset of dehydrogenation was lower compared to macrocrystalline alane (ca. 120° C. vs. 180° C.), presumably because of the small, uniform particle size of the electrosprayed alane. X-ray diffraction confirmed the formation of α-alane upon annealing at 65° C.
[0071] The SEM images in FIG. 3 show the difference in particle size and morphology between conventionally dried alane and electrosprayed alane-etherate. Image (A) shows alane-etherate that was vacuum dried and ground with a mortar and pestle, image (B) shows 0.5 weight percent alane in diethyl ether after electrospraying, image (C) shows 1.0 weight percent alane in diethyl ether after electrospraying, and image (D) shows 1.0 weight percent alane in diethyl ether after electrospraying and annealing at 65° C. Electrosprayed 1 weight percent alane solutions had a range of particle sizes from 1 um to 500 nm, while electrosprayed 0.5 weight percent alane solutions had a particle size in the range of 300 nm to 100 nm Thus, the solution concentration affected particle size, with the more dilute alane solution producing smaller particles. The uniformity of the particle size (fine particle size with consistent morphology) was maintained after annealing the electrosprayed alane particles at 65° C. In comparison, the vacuum dried sample, even after grinding, showed a very inconsistent morphology.
[0072] This example demonstrates that electrospraying improves the process of alane production, by making it easier to remove the solvent, eliminating the need for a vacuum drying stage, and consistently producing the correct phase with a beneficial morphology.
[0073] There are two possible ways that electrospraying could work on a large scale:
[0000] 1. The spraying process is refined such that AlH 3 is obtained directly, without subsequent annealing or other treatment; and
2. The spraying process is followed immediately by an annealing stage. The first alternative is preferred, but the second is acceptable, particularly if done in a continuous process, for example when the etherate is sprayed onto a hot roller where it is annealed then collected for pelletization, such as shown in FIG. 4 . The alane preparation process 100 includes preparation of an alane-etherate solution, as represented by reference number 102 . The solution is supplied (such as by a manifold 104 ), to a plurality of spray nozzles 106 . A high voltage direct current from a power source 114 is applied via circuit 116 to the nozzles 106 , producing plumes 108 of droplets of the alane-etherate. The at least partially desolvated material is collected on a conveyor 110 , which can be heated (e.g., by heated rollers 112 ) to anneal the alane and/or remove the remaining ether. The alane is removed from the conveyor and transferred (arrow 118 ) for further processing (e.g. stabilization, pelletization, collection, packaging, etc.), as represented by reference number 120 .
[0074] Alane-etherate that is desolvated by electrospraying can be produced with a small, controllable particle size, making the alane more advantageous for use in hydrogen generators based on thermolysis or hydrolysis.
[0075] Aspects can be altered and/or extended without losing the advantages of the invention. For example:
The method for preparing the alane-etherate complex solution. Specifics of the electrospraying process, including: type of nozzle used for atomization, atomization method, droplet size, gas-to-feed ratios, feed concentration, single-capillary, dual-capillary, cone-jet mode, liquid conductivity, liquid flow rate, solution concentration, orifice diameter, capillary-to-plate distance, radioactive source strength, carrier gas flow rate, and temperature.
[0078] In a modification of the electrospraying process, the alane-etherate solution can include a polymer or polymer precursor, and fibers of alane can be produced using an electrospinning process, as described above.
[0079] The above description is considered that of the preferred embodiments only. Modifications of the invention will occur to those skilled in the art and to those who make or use the invention. Therefore, it is understood that the embodiments described above is merely for illustrative purposes and not intended to limit the scope of the invention, which is defined by the following claims as interpreted according to the principles of patent law, including the Doctrine of Equivalents.
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The invention relates to methods of preparing α-alane by desolvating an alane-etherate complex. The methods include electrospraying or electrospinning the alane-etherate complex in order to remove solvent. Solid alane is obtained and can be in either fine particulate form or fiber form. The alane can be encapsulated with a stabilizing agent.
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RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 60/296,794, filed Jun. 8, 2001, the disclosure of which is incorporated herein by reference in its entirety as if set forth fully herein.
FIELD OF THE INVENTION
[0002] The present invention relates generally to sediment removal and, more particularly, to methods and apparatus for removing sediment from liquid.
BACKGROUND OF THE INVENTION
[0003] Abrasive jet cutting machines are used in many industries for machining various types of products and materials. An abrasive jet cutting machine mixes abrasive material, such as garnet, with high pressure fluid (e.g., water) flowing at a high rate of speed. After a machining operation, the abrasive fluid typically accumulates in a catcher tank where the abrasive material settles to the bottom. Over time, the amount of abrasive material in the catcher tank builds up and must be removed. Removing the abrasive material by conventional methods such as manual shoveling or vacuum suction typically involves shutting the jet cutting machine down, which may be economically undesirable.
[0004] U.S. Pat. Nos. 4,872,975 (the '975 patent) and 5,979,663 (the '663 patent) describe methods for continuously separating and recovering abrasive material without requiring that the jet cutting equipment be shut down. The method proposed by the '975 patent involves separating abrasive material from a slurry via a centrifugal pump and settling tank. The centrifugal pump separates some of the abrasive from the slurry via centrifugal force and the settling tank is used to separate the remaining abrasive material. Unfortunately, centrifugal pumps are generally not recognized as being reliable when handling abrasive materials. Centrifugal pumps may be susceptible to wear and clogging in the presence of abrasive materials, which may require significant and costly maintenance.
[0005] The '663 patent describes a method for recovering garnet using a diaphragm pump and coarse filter. Although generally recognized as being more effective at handling solids than centrifugal pumps, diaphragm pumps may also be susceptible to wear and clogging in the presence of abrasive material, which may require significant and costly maintenance.
[0006] International Pat. App. Nos. WO 99/55492 and WO 01/14102 describe respective methods of using gas bubbles injected into an arrangement of conduits to move a slurry mixture of garnet and water into a settling container. Unfortunately, the proposed arrangements of conduits is somewhat complex, and utilizes multiple horizontal runs and elbows which can become obstructed with abrasive material. Typically, a back-flushing operation is required to remove clogs from the conduit.
[0007] The principal of using compressed air bubbles to lift water from a well or other source is well documented (e.g., see Section 4 - 4 of US Army Field Manual FM 5-484 dated Mar. 8, 1994).
SUMMARY OF THE INVENTION
[0008] The present invention utilizes a system of controlled air pulses and a passive collection system to continuously remove solids and other types of materials (e.g., sediment) that have settled to the bottom of a vessel (e.g., a waterjet catcher tank) or other liquidcontaining basin. Embodiments of the present invention can overcome the limitations of prior art methods for removing abrasive material described above by eliminating the need for centrifugal or diaphragm pumps and horizontal conduits, valves and tank penetrations.
[0009] Embodiments of the present invention utilize controlled pulses of pressurized air into a single extraction device or multiple extraction devices for conveying a slurry of fluid and sediment (e.g., garnet/abrasive material) to one or more holding and/or settling reservoirs. The garnet/abrasive material can be emptied from the reservoir or recycled using various methods. Embodiments of the present invention may require no moving parts that are exposed to abrasive material flow. Moreover, centrifugal or diaphragm pumps are not required, thereby reducing equipment down time and maintenance requirements.
[0010] According to embodiments of the present invention, an apparatus for removing sediment (e.g., abrasive material such as garnet) from a liquid (e.g., water) includes a first vessel disposed at a first elevation, a second vessel disposed at a second elevation that is higher than the first elevation, a third vessel disposed at a third elevation that is lower than the second elevation, and a fourth vessel at fourth elevation that is lower than the third elevation. The first vessel contains a liquid and a layer of sediment therewithin. A first conduit defines a first fluid path between an inlet and an outlet. The first conduit inlet is positioned adjacent to (or within) the layer of sediment and the first conduit outlet is in fluid communication with the second vessel.
[0011] According to embodiments of the present invention, a penetration stop may be secured to the first conduit and may be utilized to limit how far the first conduit inlet extends into the layer of sediment. According to embodiments of the present invention, the penetration stop rests on top of the sediment in the first vessel.
[0012] An air source directs pulses of pressurized air into the first conduit to cause a slurry of liquid and sediment to flow through the first conduit into the second vessel. A second conduit defines a second fluid path between an inlet in fluid communication with the second vessel and an outlet in fluid communication with the third vessel. The second conduit is configured to drain a slurry of liquid and sediment from the second vessel into the third vessel.
[0013] The fourth vessel is configured to receive liquid from the third vessel. A third conduit defines a third fluid path between an inlet in fluid communication with the third vessel and an outlet in fluid communication with the fourth vessel. The third conduit is configured to drain liquid from the third vessel into the fourth vessel as sediment accumulates within the third vessel. A fourth conduit defines a fourth fluid path between an inlet in fluid communication with the fourth vessel and an outlet in fluid communication with the first vessel. The fourth conduit is configured to drain liquid from the fourth vessel into the first vessel.
[0014] A fifth conduit defines a fifth fluid path between an inlet in fluid communication with the second vessel and an outlet in fluid communication with the first vessel. The fifth conduit serves as a pressure relief conduit for the second vessel.
[0015] According to embodiments of the present invention, the first conduit is a vertically-oriented, elongated tube having an inlet on one end and an outlet on the opposite end. The outlet is in fluid communication with the second vessel that is elevated above the first vessel. The elongated tube may be movably secured within the first vessel. For example, the elongated tube may be moved manually, or may be configured to move automatically.
[0016] According to embodiments of the present invention, the first vessel may include one or more pairs of generally horizontal slats that extend across the first vessel from one side to an opposite side thereof. The slats in each pair are preferably spaced apart so as to form a slot. The elongated tube may be moved periodically along the slot either manually or automatically.
[0017] According to embodiments of the present invention, one of the slats extending across the first vessel may include a first set of ratchet teeth disposed on an upper surface thereof. A support member for movably securing the elongated tube within the first vessel may include a second set of ratchet teeth that are configured to matingly engage with the first set of ratchet teeth. Vibration of the first conduit caused by pulsed air flow through the first conduit causes the second set of ratchet teeth to move along the first set of ratchet teeth at a predetermined speed. Accordingly, the elongated tube may be configured to move along a predetermined direction automatically.
[0018] The first conduit inlet may include one or more nozzles having various shapes, sizes and configurations. According to embodiments of the present invention, a nozzle assembly is provided that is in fluid communication with the first conduit inlet. The nozzle assembly includes a body, a plurality of circumferentially spaced-apart apertures formed within the body, and a plurality of passageways, wherein each passageway is in fluid communication with a respective aperture and with the first conduit fluid path. The nozzle assembly configuration is designed to create a vortex within the first conduit inlet which can facilitate sediment removal and can reduce the possibility of clogging.
[0019] According to embodiments of the present invention, a portion of one or more of the various conduits and vessels may be transparent such that flow therethrough and/or therein can be observed.
[0020] According to embodiments of the present invention, a sixth conduit may be provided to prevent clogging of the first conduit inlet. The sixth conduit includes an outlet positioned adjacent to the first conduit inlet and is configured to deliver pressurized fluid and/or air adjacent the first conduit inlet.
[0021] According to embodiments of the present invention, an apparatus for removing sediment contained within a volume of liquid is provided. Apparatus includes a vessel comprising an inlet and an outlet; an elongated, substantially linear first conduit comprising an inlet and an outlet, wherein the first conduit inlet is configured to be positioned adjacent to (or within) a layer of sediment within a volume of liquid, and wherein the first conduit outlet is in fluid communication with the vessel via the vessel inlet; an air source that is configured to direct pulses of pressurized air into the first conduit to draw a slurry of liquid and sediment through the first conduit and into the vessel; and a second conduit in fluid communication with the vessel via the vessel outlet, wherein the second conduit is configured to drain a slurry of liquid and sediment from the vessel.
[0022] According to embodiments of the present invention, a method for removing sediment (e.g., abrasive material such as garnet) from a liquid (e.g., water) contained within a first vessel includes the following steps: directing pulses of pressurized air into a conduit having an inlet disposed within the first vessel adjacent to (or within) the sediment to cause a slurry of liquid and sediment to flow through the conduit into a second vessel elevated above the first vessel, draining the slurry of liquid and sediment from the second vessel into a third vessel that is positioned at an elevation lower than the second vessel, and draining liquid from the third vessel (to another vessel or elsewhere) as sediment accumulates within the third vessel. The third vessel may be removed when accumulation of sediment therewithin reaches a predetermined amount. The accumulated sediment within the third vessel is removed and the third vessel is returned to service, or another empty vessel may be substituted therefor.
[0023] According to embodiments of the present invention, the conduit is periodically moved along a predetermined path within the first vessel. Movement may be manual or automatic. For example, the conduit may be moved along the predetermined path in response to the pulses of pressurized air flowing through the conduit.
[0024] According to embodiments of the present invention, pressurized air and/or fluid may be directed into the sediment adjacent to the conduit inlet substantially simultaneously with the step of directing pulses of pressurized air into the conduit.
[0025] An advantage of the present invention is that the slurry flow path upwardly through the conduit is substantially unobstructed and the pulse action of the pressurized air (or other gas) generates a self-priming and self-clearing action. Moreover, the conduit is substantially straight with no bends. As a result, no back-flushing is required. Further, baffles and valves are not required and a catcher tank does not need to be modified to include penetrations for the conduit. Embodiments of the present invention are also designed to be removable, thereby providing accessibility to normally submerged components not readily accessible in prior art devices.
[0026] Embodiments of the present invention are designed to function without the need for an outlet nozzle penetrating a catcher tank or connected piping, which can be susceptible to clogging and may not be readily accessible for cleaning. Eliminating the tank nozzle also may have the benefit that existing catcher tanks need not be modified to include such a nozzle.
[0027] There are other inherent economic benefits in applying embodiments of the present invention to the removal of garnet/abrasive from catcher tanks. By eliminating conventional pumps, hard piping and associated maintenance, the system can be more cost effective due to its simplicity and power consumption efficiency.
[0028] Embodiments of the present invention are not limited to the removal of abrasive material, such as garnet, from catcher tanks of water jet cutting devices. Other potential applications for embodiments of the present invention include, but are not limited to, pumping sand/water slurry to control erosion, extracting slurry from underground storage tanks, removing sediment from water fountains, removing silt from wells, and removing sediment and other solid materials from various liquid-containing basins.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The accompanying drawings, which form a part of the specification, illustrate key embodiments of the present invention. The drawings and description together serve to fully explain the invention.
[0030] [0030]FIG. 1 is a schematic illustration of a sediment removal system according to embodiments of the present invention.
[0031] [0031]FIG. 2 is an enlarged, cutaway side view of the inlet of a slurry extraction tube according to embodiments of the present invention illustrating an adjacent conduit for directing pressurized air/fluid into the sediment adjacent the slurry extraction tube inlet.
[0032] [0032]FIG. 3 is an enlarged, cutaway side view of the inlet of a slurry extraction tube according to embodiments of the present invention illustrating multiple adjacent conduits for directing pressurized air/fluid into the sediment adjacent the slurry extraction tube inlet.
[0033] [0033]FIG. 4 is a side view of the receiving vessel in the sediment removal system of FIG. 1, according to embodiments of the present invention.
[0034] [0034]FIG. 5 is a side view of a support bracket for And supporting a slurry extraction tube in the sediment removal system of FIG. 1, according to embodiments of the present invention.
[0035] [0035]FIG. 6A is an enlarged, partial side view of a nozzle assembly at the slurry extraction tube inlet, according to embodiments of the present invention.
[0036] [0036]FIG. 6B is a bottom view of the nozzle assembly of FIG. 6A taken along lines 6 B- 6 B.
[0037] [0037]FIG. 7 is a plan view of a liquid and sediment containing vessel having a plurality of pairs of adjacent slats forming slots within which slurry extraction tubes according to embodiments of the present invention are movable.
[0038] [0038]FIG. 7A is a partial side view of a slurry extraction tube of FIG. 7 taken along lines 7 A- 7 A.
[0039] [0039]FIG. 8 is a broken plan view of a liquid and sediment containing vessel having a plurality of pairs of adjacent slats forming slots within which slurry extraction tubes according to embodiments of the present invention are movable, and wherein the slurry extraction tubes are configured to move along a predetermined path via respective complimentary sets of ratchet teeth.
[0040] [0040]FIG. 8A is a partial side view of a slurry extraction tube of FIG. 8 taken along lines 8 A- 8 A illustrating ratchet teeth engagement between the slurry extraction tube support member and a vessel slat.
[0041] FIGS. 8 B- 8 D illustrate movement of a respective set of ratchet teeth for the embodiment of FIG. 8.
[0042] [0042]FIG. 9 is a partial side view of a slurry extraction tube having a ballast ball attached thereto, according to embodiments of the present invention.
[0043] [0043]FIG. 10 is an enlarged, cut-away side view of a nozzle assembly at the slurry extraction tube inlet, according to embodiments of the present invention.
[0044] [0044]FIG. 11 is an enlarged, cutaway side view of the inlet of a slurry extraction tube according to embodiments of the present invention illustrating an air conduit extension extending through the slurry extraction tube inlet.
DETAILED DESCRIPTION OF THE INVENTION
[0045] The present invention now is described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thickness of lines, layers and regions, as well as scale, may be exaggerated for clarity.
[0046] Embodiments of the present invention can provide methods and apparatus for removing sediment from various liquid locations (e.g., tanks, vessels, rivers, streams, etc.). As used herein, the term sediment means any material that settles to the bottom of a liquid and includes, but is not limited to, abrasive material from jet cutting processes, silt, sand, mud, clay, etc. According to a specific embodiment of the present invention, methods and apparatus for removing abrasive material, such as garnet, from catcher tanks of water jet cutting machines will be described herein. However, it is understood that embodiments of the present invention may be utilized to remove various other types of sediments from various liquid environments.
[0047] Embodiments of the present invention preclude the need for conventional pumps and devices that utilize moving parts which may be subjected to corrosion, erosion and clogging in the presence of abrasive material. All parts of a sediment removal system according to embodiments of the present invention that are exposed to an abrasive material are designed to function without any significant wear and without requiring significant maintenance.
[0048] Referring to FIG. 1, a sediment removal system 10 according to embodiments of the present invention is schematically illustrated. The illustrated sediment removal system 10 is configured to remove sediment (in this case, abrasive material) from a catcher tank 12 of a jet cutting machine (not illustrated). The illustrated sediment removal system 10 includes a slurry extraction conduit or tube 14 , an air source and regulator 16 for providing pulses of pressurized air (or other gas or fluid), a second vessel referred to as a receiving vessel 18 , a third vessel referred to as a primary collection tank 20 , and a fourth vessel referred to as a secondary collection tank 22 . The slurry extraction tube 14 defines a fluid path 15 between an inlet 14 a and an outlet 14 b . The inlet 14 a is positioned adjacent to (or in) the sediment 50 to be removed and the outlet 14 b is in fluid communication with the receiving vessel 18 . The slurry extraction tube 14 is designed to be self-priming and self-clearing when positioned adjacent to the abrasive material 50 or when immersed directly into the abrasive material 50 in the catcher tank 12 . The slurry extraction tube 14 conveys an abrasive slurry mixture 50 a to the receiving vessel 18 via pulses of pressurized air provided and regulated by the air source and regulator 16 . The air source and regulator 16 regulates air pressure, air volume, and air pulse cycle time.
[0049] The linear arrangement of the slurry extraction tube 14 and inlet 14 a reduces the likelihood of clogging caused by the abrasive material. In addition, a slurry extraction tube 14 may be configured to be movably inserted within various locations of a catcher tank. Although FIG. 1 illustrates a single slurry extraction tube 14 , embodiments of the present invention may utilize multiple slurry extraction tubes as illustrated in FIG. 7. Multiple slurry extraction tubes may be moved individually or collectively within a vessel.
[0050] In operation, pulses of pressurized air (or other gas or fluid) are delivered to the slurry extraction tube 14 via tubing 30 from the air source and regulator 16 to nozzle 32 . Air pulses may be delivered having an exemplary pressure of between 40 psi and 80 psi and in exemplary time intervals of between about 0.5 seconds and 2 seconds. However, embodiments of the present invention may utilize various pressures and time intervals without limitation.
[0051] The slurry extraction tube 14 is inserted within the catcher tank 12 such that the inlet 14 a is positioned adjacent to (or immersed within) the abrasive material 50 on the bottom of the catcher tank 12 . In the illustrated embodiment of FIG. 2, the nozzle 32 is attached to a penetration stop 42 that limits the distance the inlet 14 a of the slurry extraction tube 14 can be extended into the abrasive material 50 . Pulses of pressurized air provided into the slurry extraction tube 14 via nozzle 32 force a slurry of water (or other liquid that is in the catcher tank 12 ) and abrasive material 50 into the receiving vessel 18 .
[0052] Air pulses directed into the slurry extraction tube 14 draw an abrasive material slurry upward due to the change in specific gravity within the slurry extraction tube 14 . Applicants have unexpectedly found that using pulsed air is more effective for moving a slurry of abrasive material than is a steady air stream.
[0053] In the illustrated embodiment of FIG. 2, the penetration stop 42 contains a passageway 43 that is in fluid communication with the nozzle 32 and with an aperture 44 in the sleeve inner wall 45 of the penetration stop 42 . Aperture 44 is in fluid communication with an elongated aperture 46 formed within the slurry extraction tube 14 . Accordingly, air flows into the nozzle 32 through the passageway 43 and into the fluid path 15 of the slurry extraction tube 14 via apertures 44 and 46 . Elongated aperture 46 allows the slurry extraction tube 14 to be slidably moved within the penetration stop 42 , while maintaining fluid communication with air flowing through passageway 43 .
[0054] In the illustrated embodiment, the slurry extraction tube 14 is slidably supported within the penetration stop 42 . Accordingly, the extent to which the inlet 14 a can be inserted into the abrasive material can be controlled by sliding the slurry extraction tube 14 within the penetration stop 42 . Air pulses are provided within the slurry extraction tube 14 as described above via nozzle 32 which is fluid communication with the air source and regulator 16 via air supply conduit 30 .
[0055] According to embodiments of the present invention, the inlet 14 a of the slurry extraction tube 14 may incorporate one or more nozzles. These nozzles may be removable and changeable and may have various shapes, sizes and configurations. For example, FIGS. 6 A- 6 B illustrate a nozzle assembly according to embodiments of the present invention. The illustrated nozzle assembly includes a plurality of circumferentially spaced-apart apertures 41 a formed within a body 41 of the nozzle assembly, and a plurality of eccentrically positioned, radially extending passageways 41 b that are configured to create an agitation zone directly below the slurry extraction tube inlet 14 a . Each passageway 41 b is in fluid communication with a respective aperture 41 a and with the first conduit inlet 14 a . This configuration is designed to increase the amount of abrasive material in suspension and, thereby, increase removal of abrasive material. FIG. 6B is a bottom end view of the nozzle assembly of FIG. 6A illustrating the configuration of passageways 41 a . Although illustrated as a single nozzle, it is anticipated that embodiments of the present invention may utilize multiple inlet nozzles at the inlet 14 a. Various inlet nozzle sizes and configurations may be utilized without limitation.
[0056] [0056]FIG. 10 is a partial cut-away view of the nozzle assembly of FIGS. 6 A- 6 B according to embodiments of the present invention and illustrating a slurry extraction tube 14 therein. Air from the air source and regulator 16 is provided via air supply conduit 30 to nozzle 32 and then via air supply conduit extension 30 a into the slurry extraction tube inlet 14 a. A “duckbill” valve 47 (available from A. C. Hoffman Engineering Inc., 5876 Republic St., Riverside, Calif. 92504) is connected to the end of the air supply conduit extension 30 a within the slurry extraction tube inlet 14 a to prevent the ingress of abrasive slurry mixture into the air supply conduit extension 30 a . Duckbill valves are well known to those skilled in the art and need not be described further herein. Moreover, other mechanisms known to those skilled in the art may be utilized to prevent the ingress of abrasive slurry mixture into the air supply conduit extension 30 a.
[0057] [0057]FIG. 11 is an enlarged, cutaway side view of the inlet of a slurry extraction tube 14 according to other embodiments of the present invention. Air from the air source and regulator 16 is provided via air supply conduit 30 to nozzle 32 and then via air supply conduit extension 30 a into the slurry extraction tube inlet 14 a . A duckbill valve 47 is connected to the end of the air supply conduit extension 30 a within the slurry extraction tube inlet 14 a to prevent the ingress of abrasive slurry mixture into the air supply conduit extension 30 a . Other mechanisms known to those skilled in the art may be utilized to prevent the ingress of abrasive slurry mixture into the air supply conduit extension 30 a.
[0058] Referring back to FIG. 1, the abrasive material slurry 50 a within the receiving vessel 18 flows gravimetrically from the receiving vessel 18 into the primary collection tank 20 via conduit 34 . According to embodiments of the present invention, the receiving vessel 18 , or one or more portions thereof, is formed of transparent material to facilitate visual inspection of its contents. Pressure within the receiving vessel 18 is vented to the catcher tank 12 via a conduit 36 .
[0059] When abrasive material slurry 50 a flows from the receiving vessel 18 into the primary collection tank 20 , the abrasive material settles to the bottom of the liquid in the primary collection tank 20 . The liquid is drained into the secondary collection tank 22 via an overflow conduit 38 as the abrasive material accumulates in the primary collection tank 20 . The primary collection tank 20 , thus, fills with abrasive material and can be removed from the system 10 and emptied when full. Water in the secondary collection tank 22 is drained back to the catcher tank 12 via conduit 39 .
[0060] According to embodiments of the present invention, one or more of the various conduits 34 , 36 , 38 , 39 may be transparent to permit visual inspection of flow therethrough. In addition, one or more of the various conduits 34 , 36 , 38 , 39 may be flexible tubing.
[0061] According to embodiments of the present invention illustrated in FIGS. 2 - 3 , one or more optional clearing tubes 60 may be utilized to blow pressurized pulses of gas (e.g., air) and/or liquid (e.g., water) directly into the abrasive material 50 adjacent the inlet 14 a of the slurry extraction tube 14 . If the inlet 14 a of the slurry extraction tube 14 is extended too far into the abrasive 50 , pressurized liquid and/or gas provided via a clearing tube 60 can clear the inlet 14 a (including any nozzles utilized with the inlet 14 a ) and can initiate the flow of abrasive slurry upwardly into the slurry extraction tube 14 . Air flow through a clearing tube 60 may be controlled by the air source and regulator 16 .
[0062] [0062]FIG. 3 illustrates two clearing tubes 60 positioned on respective opposite sides of a slurry extraction tube 14 , according to embodiments of the present invention. Each clearing tube 60 may be configured to deliver pressurized gas and/or liquid as described above. Moreover, one clearing tube 60 may be configured to deliver pressurized gas and the other clearing tube 60 may be configured to deliver pressurized liquid.
[0063] The outlet 14 b of the slurry extraction tube extends upwardly into the receiving vessel 18 . An enlarged side view of the receiving vessel 18 is illustrated in FIG. 4. The receiving vessel 18 is configured to receive the abrasive slurry from the slurry extraction tube outlet 14 b and then allow the abrasive slurry 50 a to drain gravimetrically to the primary collection tank 20 . According to embodiments of the present invention, the receiving vessel 18 is transparent or has one or more portions that are formed from transparent material (e.g., clear plastic, glass, etc.) to permit inspection of abrasive slurry flow during operation. The receiving vessel 18 may have various shapes, sizes and configurations according to embodiments of the present invention and is not limited to the illustrated embodiment. Moreover, embodiments of the present invention are not limited to the illustrated shapes and configurations of any of the components of the sediment removal system 10 .
[0064] Referring back to FIG. 1, operations of the illustrated abrasive removal system 10 will now be described. With the inlet 14 a of the slurry extraction tube 14 inserted into (or adjacent to) the abrasive material 50 , the operation cycle begins as the air source and regulator 16 releases pulses of pressurized air into the nozzle 32 through the supply tube 30 . To generate pulses, the air source and regulator 16 may utilize a commercially available solenoid valve, on-off switch, time delay relay or PLC and a filter regulator, as would be understood by those skilled in the art. It should be understood that pulses of pressurized gas other than air may be utilized according to embodiments of the present invention.
[0065] The abrasive slurry mixture is directed into the receiving vessel 18 . The receiving vessel 18 redirects the abrasive slurry flow to the primary collection tank 20 by gravity through conduit 34 . The primary collection tank 20 receives the abrasive slurry and settling of the abrasive material begins. As water (or other slurry liquid) rises in the primary collection tank 20 , excess water overflows into the secondary collection tank 22 through conduit 38 . The secondary collection tank 22 contains primarily clear water with minor abrasive carry-over which settles to the bottom thereof.
[0066] According to other embodiments of the present invention, the secondary collection tank 22 may be eliminated and water or other slurry fluid may be returned directly to the catcher tank 12 or to another location. Alternatively, multiple additional secondary collection tanks 22 may be utilized.
[0067] The overflow of water in the secondary collection tank 22 is returned to the catcher tank 12 by gravity through conduit 39 . When the primary collection tank 20 is full, or nearly full, of abrasive material, air flow into the slurry extraction tube 14 can be stopped and the primary collection tank 20 can be emptied or replaced with an empty tank.
[0068] According to embodiments of the present invention, the slurry extraction tube 14 may be supported on or within the catcher tank 12 in various ways. For example, as illustrated in FIG. 4, a support bracket 90 may be configured to attach the slurry extraction tube 14 to a side wall of a catcher tank 12 or to a slat or other member extending thereacross.
[0069] Referring to FIGS. 7 - 7 A, a support bracket 91 is configured to support a slurry extraction tube 14 disposed within a slot 92 formed by a pair of spacedapart, adjacent slats 93 that extend across the catcher tank 12 . In the illustrated embodiment, multiple pairs of slats 93 and corresponding slots 92 are provided. A slurry extraction tube 14 is be inserted into the catcher tank 12 through a respective slot 92 and can be moved within the tank 12 as indicated by arrow A, as well as upwardly and downwardly into the contents of the catcher tank.
[0070] Various support devices may be utilized to support slurry extraction tubes within tanks and vessels according to embodiments of the present invention. The present invention is not limited to the illustrated support bracket embodiments.
[0071] In the illustrated embodiment, the plurality of slurry extraction tubes are movable collectively within slots 92 via connectors 94 . However, a plurality of slurry extraction tubes 14 may be moved individually and need not be connected.
[0072] According to additional embodiments of the present invention illustrated in FIGS. 8 - 8 D, slurry extraction tubes 14 may be configured to automatically move within a catcher tank or other vessel. As illustrated in FIGS. 8 - 8 A, each slat 93 includes a set of ratchet teeth 95 on an upper surface 93 a thereof. The support bracket 92 may include a corresponding complimentary set of ratchet teeth 96 that are configured to matingly engage the ratchet teeth 95 on the slat 93 . Vibration of the slurry extraction tube 14 caused by the pulsing of air therethrough is configured to cause the slurry extraction tube 14 to “walk“ along the slat at a predetermined speed. For example, in FIG. 8B, vibration caused by the pulsed air is not enough to lift the support bracket 91 and slurry extraction tube 14 secured thereto. In FIG. 8C, the air pulses have caused enough vibration to cause the support bracket 91 and slurry extraction tube 14 secured thereto to rise upwardly slightly (indicated by arrow A 1 ). The ratchet teeth configuration causes the support bracket 91 to move in a predetermined direction (indicated by arrow A 2 ) by one tooth (or by multiple teeth depending on the ratchet teeth configuration). The ratchet teeth on the support bracket 91 and slat 93 then reengage in mating relationship as illustrated in FIG. 8D until vibration is sufficient to raise the support bracket 91 again.
[0073] According to another embodiment of the present invention and illustrated in FIG. 9, a ballast ball 100 may be attached to a portion of a slurry extraction tube 14 that is submerged beneath the water level in a catcher tank. The ballast ball 100 is configured to facilitate buoyancy of the slurry extraction tube 14 such that movement of the slurry extraction tube 14 within a liquid requires reduced force.
[0074] The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although a few exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. The invention is defined by the following claims, with equivalents of the claims to be included therein.
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Methods and apparatus for removing sediment from a liquid are provided. Pulses of pressurized air are directed into a conduit having an inlet disposed within a first liquid-containing vessel adjacent to (or within) the sediment to cause a slurry of liquid and sediment to flow through the conduit into a second vessel elevated above the first vessel. The slurry of liquid and sediment is allowed to drain from the second vessel into a third vessel that is positioned at an elevation lower than the second vessel. Liquid is drained from the third vessel (to another vessel or elsewhere) as sediment accumulates within the third vessel. The third vessel may be removed when accumulation of sediment therewithin reaches a predetermined amount. The accumulated sediment within the third vessel is removed and the third vessel is returned to service, or another empty vessel may be substituted therefor.
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[0001] The present invention relates to a shifting device which has at least one coupling device, a shaft, a shifting collar of the coupling device which is situated in an axially shiftable and rotatably fixed manner on the shaft and an actuator system of the coupling device for axially shifting the shifting collar, at least one coupling toothing being assigned to the coupling element, which is able to rotate around a rotation axis relative to the shaft, and at least one mating toothing corresponding to the coupling toothing being rotatably fixedly assigned to the shifting collar, and at least one annular actuator element of the actuator system surrounding the shifting collar around the rotation axis on the circumferential side.
BACKGROUND
[0002] EP 1977130 B1 shows a shifting device of this type. The shifting device has a coupling element which is rotatably supported on the shaft relative to the shaft. The coupling element should be rotatably fixedly connected to the shaft via the shifting collar upon engagement of a gear and be able to rotate again relative to the shaft upon changing gears. For this purpose, the shifting collar is situated on the shaft in an axially shiftable and rotatably fixed manner and therefore is shiftably supported on a hub which is fixedly connected to the shaft.
[0003] The rotatably fixed, detachable connection between the shifting collar and the coupling element is implemented with the aid of tooth engagement. For this purpose, a coupling toothing, which corresponds to a mating toothing on the shifting collar, is provided on the coupling element. The teeth of the toothings and the tooth gaps are longitudinally oriented, so that when a gear is engaged, the teeth of the mating toothing are insertable into the tooth gaps of the coupling toothing until the teeth of the toothings are alternately opposite each other in the circumferential direction and are thus rotatably fixedly coupled. An electromagnetic actuator system for actuating the shifting collar or an annular element of the actuator system surrounds the shifting collar on the circumferential side, so that the shifting device may have a very compact design.
[0004] Coupling elements may be, for example, gear wheels, so-called idler gears, on which the coupling toothing is provided directly. Alternatively the coupling elements are coupling members having the coupling toothing which are rotatably fixedly coupled with a gear wheel.
[0005] The installation space required by a shifting device of this type is dependent on the radial and axial dimensions of the coupling element and the shifting collar. The dimensions of the electromagnetic actuator are dependent on the forces needed for shifting. The installation space required by the shifting device is therefore essentially also influenced by the size of the actuator system and may therefore be large if a great deal of power is required.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide a shifting device in which the installation space required is largely independent of the shifting forces.
[0007] The present invention provides that the annular actuator element is at least one gear shift drum. A gear shift drum is understood to be a component of a partially hollow cylindrical design or a completely hollow cylindrical design which is preferably made of sheet metal.
[0008] The gear shift drum has at least one guideway but may also have two or more guideways. The guideways are, for example, grooves which are introduced into the gear shift drum. These grooves radially penetrate the wall of the gear shift drum or have a closed groove base. In gear shift drums made of sheet metal, the guideways are punched or rolled in. Punched guideways extend beyond a partial circumference and are provided on gear shift drums which are pivotable around the pivot axis. The pivot axis corresponds to the rotation axis of the coupling element. Rolled-in guideways extend beyond a partial circumference and are provided on pivotable gear shift drums. Alternatively, the rolled-in guideways run around the entire circumference, so that they may also be used on rotating gear shift drums.
[0009] Alternatively, the guideways are rail-like structures which are mounted radially on the inner circumference of the gear shift drum or which project from the inner circumferential surface of the gear shift drum and which are provided with a simple I-shaped or U-shaped design in any longitudinal sections along the rotation axis and whose legs project radially to the inside.
[0010] Mounted or projecting guideways extend beyond a partial circumference and are provided on pivotable gear shift drums. Alternatively, the mounted or projecting guideways run around the entire circumference, so that they may also be used on rotating gear shift drums.
[0011] The guideways are essentially oriented in the circumferential direction of the gear shift drum, i.e., also in the circumferential direction around the rotation or pivot axis, but they do not run on a circumferential line but are deflected from an imaginary circumferential line in axial directions, optionally run back in the axial direction, etc. This course is dependent on the shifting times and the axial lift to be covered by the shifting collar.
[0012] A guiding element is coupled with the shifting collar in such a way that the shifting collar is rotatable around the rotation axis relative to the guiding element but may be entrained by the guiding element in the axial direction. The guiding element radially engages with the particular guideway. The gear shift drum having the guideway is movable relative to the guiding element, so that the guiding element is positively moved axially in a pivoted or rotating guideway and axially entrains the shifting collar.
[0013] The pivot or rotary drive of the gear shift drum is integrated, for example, into the gear shift drum and is preferably electromotive. However, the drive of the gear shift drum is preferably situated outside the gear shift drum. The latter approach has the advantage that a coupling device may be concentrically integrated into the gear shift drum, as provided by one embodiment of the present invention. In this case, the gear shift drum itself takes up only the radial installation space, which is determined by the wall thickness of its hollow cylinder and the height of any projecting guideways. The dimensions of the annular actuator element are thus essentially independent of the shifting forces. In this case, the gear shift drum may be connected to the drive by a geared connection. Geared connections are belt or chain drives or gear stages. One element, for example a gear wheel or a pulley, is attached to the gear shift drum. Alternatively, this element is integrated into a gear shift drum as a single piece, for example as a toothing on a spur wheel section.
[0014] One embodiment of the present invention provides that the gear shift drum has a radial flange which projects radially beyond the circumference of the gear shift drum. At least one element of the geared connection is attached to or formed on this flange. The flange is optionally also used for the pivotable or rotatable support of the gear shift drum in relation to the surrounding structure.
[0015] Other embodiments of the present invention relate to a shifting device in which the coupling device is at least partially concentrically situated within the gear shift drum. The coupling device has the shifting collar and at least one coupling member, preferably two coupling members. In the latter case, the shifting collar has a dual-action design and is mounted axially between the two coupling members. The coupling toothing is provided on each coupling member.
[0016] The shifting collar is axially shiftably positioned either directly on a shaft or on a hub which is formed with the shaft or is attached thereto. The sliding seat in both cases is supported on a sliding or rolling bearing with the aid of splines or other suitable profiles.
[0017] One embodiment of the present invention provides that one or multiple locking elements is/are situated radially between the hub and the shifting collar. The locking element(s) is/are made of at least one spring and one bolt pretensioned by the spring, alternatively having a pretensioned ball. The locking element is guided or held in the hub and supported radially against the spring forces. The ball or the locking bolts interlock with trough-shaped indentations when the gears are engaged or in the neutral position and thereby hold the shifting collar in the desired position relative to the shaft.
[0018] One embodiment of the present invention provides that the coupling device has at least one friction surface which is torsionally fixedly coupled with the shaft but is able to be shifted axially relative to the shaft with the aid of the shifting collar. The friction surface is shiftable on a mating friction surface which is torsionally fixedly coupled with the coupling element and corresponds to the friction surface. The friction surfaces are provided on separate friction members. One of the friction members is torsionally fixedly coupled with the shaft and may be axially shifted by the shifting collar. The other friction member is rotatably fixedly coupled with the coupling member. Alternatively, the friction surfaces are provided directly on the shifting collar or the coupling member. The shaft and the particular coupling member may be braked against each other with the aid of a friction coupling of this type between the shaft and the particular coupling member until the rotational speeds are synchronous. As in the case of synchronous couplings, the engagement of the particular gear is comfortable with the aid of an arrangement of this type.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 shows an electromotively driven drive unit 1 in a longitudinal sectional view along its main axis 18 , drive unit 1 including an electric machine 19 and a transmission 55 . Transmission 55 has a shifting device 56 and a planetary gear 59 . Shifting device 56 includes a coupling device 25 and a drive 23 having a geared connection 24 .
[0020] FIG. 2 shows the shifting device 56 in an overall view including drive 23 and geared connection 24 .
[0021] FIG. 3 shows coupling device 58 in a longitudinal sectional view along main axis 18 according to FIG. 2 .
DETAILED DESCRIPTION
[0022] FIG. 1 : Coupling device 25 has a gear shift drum 22 , coupling elements 26 , 28 and 30 , a shifting collar 97 and a guiding element 42 . Shifting collar 97 is mounted in an axially shiftable and rotatably fixed manner on coupling element 26 , which is designed as a hub 2 . Hub 2 is rotatably fixedly situated on a shaft 3 which is part of connecting shaft 67 of planetary gear 59 and to which an annulus gear 64 of planetary gear 59 is connected. Actuator system 6 of coupling device 58 is illustrated in its entirety in FIG. 2 .
[0023] Coupling element 28 is rotatably situated on a rotor shaft 29 of electric machine 19 around rotation axis 18 ′ on main axis 18 relative to shaft and has a coupling toothing 4 . Coupling element 30 is fixed on a housing 39 ; however, shaft 3 is able to rotate around rotation axis 18 ′ relative to coupling element 30 . Coupling element 30 is provided with a coupling toothing 5 . Shifting collar 97 has a mating toothing 7 and 8 on each side in the axial direction. Toothings 7 and 8 correspond to particular coupling toothings 4 and 5 , which are located axially opposite each other.
[0024] The annular actuator element designed as gear shift drum 22 is hollow cylindrical and surrounds shifting collar 97 and coupling elements 26 , 28 and 30 , running around rotation axis 18 ′ on the circumferential side.
[0025] FIGS. 2 and 3 : As is apparent, in particular, from FIGS. 2 and 3 , gear shift drum 22 has a hollow cylindrical section 9 and a radial flange 10 . Hollow cylindrical section 9 and radial flange 10 form a single piece with each other. Guideways 41 are provided in section 9 . However, each of guideways 41 is essentially not aligned with a circumferential line but is deflected axially to the left and right. As a result, particular guideway 41 has a curve-shaped course.
[0026] Particular guiding element 42 , which engages with one of guideways 41 , is fixedly inserted into an outer bearing ring 11 . Outer bearing ring 11 is a component of a rolling bearing 12 , which furthermore includes an inner bearing ring 14 and rolling members 13 . Rolling members 13 are balls and are radially situated between inner and outer bearing rings 14 and 11 . Inner bearing ring 14 is fixedly mounted on shifting collar 97 . An axially fixed connection is established between shifting collar 97 and gear shift drum 22 via guiding elements 42 engaging with guideways 41 and rolling bearing 12 in such a way that shifting collar 97 is axially entrained when gear shift drum 22 pivots around rotation axis 18 ′. However, shifting collar 97 is movable relative to gear shift drum 22 due to rolling bearing 12 .
[0027] Shifting collar 97 is axially shiftably connected to hub 2 via a spline or similar shaft-hub connections and, according to the representation in FIG. 3 , it is in a neutral position between toothings 4 and 5 on coupling elements 28 and 30 designed as coupling members 16 and 17 . A locking element 15 is accommodated in hub 2 . Locking element 15 is radially pretensioned against shifting collar 97 by a screw spring and interlocked in an indentation 20 in shifting collar 97 .
[0028] Coupling device 58 has friction members 25 and 43 which are torsionally fixedly coupled with hub 2 but are axially shiftable in relation to hub 2 with the aid of shifting collar 97 . An inner conical friction surface 44 or 45 is provided on each of friction members 25 and 43 . An outer conical mating friction surface 21 or 46 for particular friction surface 44 or 45 is provided on each of coupling members 16 and 17 . Friction surface 44 may be frictionally engaged with mating friction surface 21 and friction surface 45 may be frictionally engaged with mating friction surface 46 by axially shifting shifting collar 97 .
[0029] Actuator system 6 has an electric motor 80 as drive 23 which is situated in parallel to electric machine 19 . A geared connection 24 is formed by an intermediate shaft 47 and two gear stages 48 and 49 . Gear stage 48 has a pinion 50 , which is provided on pivot shaft 51 of electric motor 80 , and a spur wheel 52 on intermediate shaft 47 , which are in tooth engagement with each other. Gear stage 49 is provided with a pinion 53 , which is provided on intermediate shaft 47 and which is in tooth engagement with a tooth segment 54 . Tooth segment 54 is provided on flange 10 or is alternatively attached thereto.
[0030] FIGS. 1 and 3 : Flange 10 is rotatably supported on surrounding structure 63 with the aid of two rolling bearings 60 and 62 in a pivotable manner around rotation axis 18 ′. Surrounding structure 63 includes an end shield 66 and an intermediate wall 68 which are fixed to housing 39 . End shield 66 separates an inner chamber of electric machine 19 , which includes stator 40 and rotor 38 , and rotor shaft 29 from coupling device 58 . Rotor shaft 29 is also supported on end shield 66 . Coupling device 58 and planetary gear 59 are separated from each other by intermediate wall 68 .
[0031] FIG. 3 : Rolling bearing 60 has a track 69 , oriented in the circumferential direction, which is provided directly in flange 10 , e.g., by embossing in flange 10 . Another track 70 is provided in a mirror-image configuration in intermediate wall 68 . Rolling bearing 62 has a track 71 , oriented in the circumferential direction, which is provided directly in flange 10 . A track 72 , which is provided on a spring element 73 , is provided in a mirror-image configuration in relation to track 71 . Multiple balls 77 are situated between tracks 69 and 70 as rolling members.
[0032] Spring element 73 is either attached to or at least axially supported on end shield 66 . The rolling bearing arrangement is axially pretensioned between end shield 66 and intermediate wall 68 with the aid of elastically resilient spring element 73 . Tracks 69 , 70 , 71 and 72 either run as circular tracks around the entire circumference or are circular arc segment tracks whose arc angle corresponds to the maximum pivot angle of gear shift drum 22 . In the latter arrangement, at least two of the same circular arc segment tracks are situated on the circumferential side. Tracks 69 , 70 , 71 and 72 are also designed as ball grooves/track grooves which form a trough adapted to balls 77 in the longitudinal sectional view.
[0033] Tracks 69 and 70 are radially offset in relation to tracks 71 and 72 . The one track 69 is provided on the one axially oriented front face 74 of flange 10 , and the other track 71 is provided on a front face 75 of flange 10 which is oriented in the opposite direction from front face 74 . Due to an offset 76 in flange 10 , which is provided radially between tracks 69 , and due to the trough-shaped molding of the track grooves in the longitudinal sectional view, the ball grooves touch a shared imaginary radial plane 78 at their axially lowest point, radial plane 78 being axially penetrated perpendicularly by rotation axis 18 ′ and therefore intersecting both tracks 71 and 72 in the groove base. As a result, the roller bearing arrangement requires less axial installation space.
[0034] FIGS. 4 and 5 shows a shifting device 56 which essentially corresponds to shifting device 56 described in FIGS. 2 and 3 , whose actuator system 79 , however, is provided with modifications of drive 23 and geared connection 24 . Electric motor 90 of actuator system 79 has a pivot shaft 81 on which a pinion 82 is provided. Pinion 82 is in tooth engagement with a reversing gear wheel 83 , which is rotatably supported on an intermediate shaft 84 with the aid of a hub 185 . Intermediate shaft 84 is fixed to an intermediate wall 85 .
[0000]
List of Reference Numerals
1
Drive unit
2
Hub
3
Shaft
4
Coupling toothing
5
Coupling toothing
6
Actuator system
7
Mating toothing
8
Mating toothing
9
Hollow cylindrical section
10
Flange
11
Outer bearing ring
12
Rolling bearing
13
Rolling member
14
Inner bearing ring
15
Locking element
16
Coupling member
17
Coupling member
18
Main axis
19
Electric machine
20
Indentation
21
Mating friction surface
22
Gear shift drum
23
Drive for gear shift drum
24
Geared connection
25
Friction member
26
Coupling element
27
Output shaft
28
Coupling element
29
Rotor shaft
30
Coupling element
39
Housing
40
Stator
41
Guideway
42
Guiding element
43
Friction member
44
Friction surface
45
Friction surface
46
Mating friction surface
47
Intermediate shaft
48
Gear stage
49
Gear stage
50
Pinion
51
Pivot shaft
52
Spur wheel
53
Pinion
54
Tooth segment
55
Transmission
56
Shifting device
57
Geared connection
58
Coupling device
59
Planetary gear
60
Rolling bearing
61
Sun wheel
62
Rolling bearing
63
Surrounding structure
64
Annulus gear
65
Connecting shaft
66
End shield
67
Connecting shaft
68
Intermediate wall
69
Track
70
Track
71
Track
72
Track
73
Spring element
74
Front face
75
Front face
76
Offset
77
Balls
78
Radial plane
79
Actuator system
80
Electric motor
81
Pivot shaft
82
Pinion
83
Reversing gear wheel
84
Intermediate shaft
85
Intermediate wall
86-89
90
Electric motor
91-96
97
Shifting collar
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A shifting device including at least one coupling device, a shaft, a sliding sleeve-of the coupling device which is arranged in an axially moveable and rotationally fixed manner on the shaft and an actuator arrangement of the coupling device for axially moving the sliding sleeve. At least one coupling toothing is associated with the coupling element which can rotate about a rotational axis with respect to the shaft and a counter toothing corresponding to the coupling toothing is associated with the sliding sleeve in a rotationally fixed manner. At least one annular actuator element of the actuator arrangement surrounds the periphery of the sliding sleeve about the rotational axis.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an apparatus for carrying out a Standard Penetration Test (SPT) to determine the penetration resistance, geological distribution and nature of the soil, and more particularly to an automatic hammer system for a standard penetration test, which enables its hammer to fall from a precise predetermined height regardless of a penetration depth of a sampler, and is able to automatically carry out sequential test procedures such as counting the number of blows by the hammer and a penetration depth of a sampler according to the number of blows.
[0003] 2. Description of the Prior Art
[0004] To undertake various civil engineering works and construction works, there is a need to first determine the penetration resistance, geological structure and geological composition of the soil by checking consistency and relative density of the soil by testing the soil of an area in question. To this end, a test procedure known as the “Standard Penetration Test” is commonly used.
[0005] The standard penetration test is a representative geological surveying test for estimating soil constants such as strength, relative density and angle of internal friction of ground in question, which is carried out as follows. A hammer of 63.5 kg is raised to a height of 75 cm and then released to fall and impact a split barrel sampler (referred to merely as a sampler, hereinafter), and this procedure is repeatedly carried out until the soil is penetrated to a depth of 30 cm by the sampler. Subsequently, an N value, which is the number of blows of the hammer counted until the sampler penetrates the soil to the depth of 30 cm, is calculated, and the soil constants of the ground are obtained from the N value.
[0006] In this test, the number of blows counted until the sampler initially penetrates the soil to a depth of 15 cm is regarded as a number of preliminary blows because the soil sample is believed to be disturbed, and the number of blows counted until the sampler further penetrates the soil to a depth of 30 cm from the level corresponding to the initial depth of 15 cm is determined as the N value for the soil in question. Where the number of blows counted until the sampler penetrates the soil to the depth of 30 cm exceeds 50, a depth of the soil penetrated after the hammer gives the sampler 50 blows is measured.
[0007] As a rule, though the standard penetration test must be carried out every 1.5 m under the current ground surface, the standard penetration test is carried out only once where the same geological formation continues underground.
[0008] Referring to FIG. 1, there is shown the most common apparatus for use in the standard penetration test, which uses a winch.
[0009] As shown in the drawing, a frame 1 is provided at its lower portion with a winding drum 2 fixed thereto, and is provided at its upper portion with a pulley 3 . A rope 4 is wound around the winding drum 2 for several turns and wrapped around the pulley 3 to be directed downwardly. A cylindrical hammer 5 is coupled to one end of the rope 4 , and slidably inserted over a vertical guide rod 6 .
[0010] The guide rod 6 is coupled at its lower end to a drill rod 8 , which is inserted into a boring hole (not shown) which has been previously drilled. The drill rod 8 is provided at its upper end with an anvil 7 mounted thereon, on which the hammer 5 impacts, and is provided at its lower end with a sampler (not shown) coupled thereto to obtain a disturbed soil sample. The guide rod 6 is provided with a marking which indicates a maximum lifting height at a certain height from the anvil 7 .
[0011] In an operation of the winch-type apparatus, the drill rod 8 , on which the sampler is mounted, is inserted into the boring hole of the soil, and then coupled to the guide rod 6 . Subsequently, the rope 4 is pulled by an operator to raise the hammer 5 to the lifting height (75 cm), and then released to allow the hammer 5 to free fall. Consequently, the hammer 5 falls along the guide rod 6 and impacts the anvil 7 .
[0012] Therefore, the impact of the falling hammer 5 is transmitted to the drill rod 8 through the anvil 7 , so that the soil in question is penetrated by the sampler coupled to the lower end of the drill rod 8 . This procedure is repeated until the penetrated depth reaches a desired value.
[0013] However, since such a conventional winch-type apparatus for use in the standard penetration test is required for an operator to check, with his naked eye, a lifting height of the hammer 5 during every lifting procedure, it is difficult to maintain a constant lifting height throughout all the striking procedures even though the test is carried out by a skilled person. Hence, the drill rod is applied with different impact strengths throughout the striking procedures.
[0014] Furthermore, since the hammer 5 is raised by the rope 4 , frictional loss is generated between the winding drum 2 and the pulley 3 during the falling of the hammer 5 . The frictional loss varies depending on the properties and age of the rope 4 , and actual impact strength applied to the anvil 7 is reduced to a value lower than the specified value.
[0015] Therefore, the conventional winch-type apparatus is inadequate to carry out the standard penetration test, and it is difficult to assure a precise measurement of an N value and to assure reliability of test results because of various factors.
[0016] In addition, since an N value obtained by the test is in an operator's memory, and a penetration depth of the sampler is obtained by an additional measuring procedure, an operator is apt to obtain incorrect test results, and considerably different test results may be obtained depending on operators even though the tests are carried out on the same soil sample.
[0017] To overcome the above-mentioned problems, a drive hammer system for a standard penetration test is disclosed in U.S. Pat. No. 4,405,020, which is adapted to enable a hammer to consistently fall from the same height, and to minimize frictional loss generated during the falling of the hammer.
[0018] The drive hammer system is slidably supported to an outer surface of a hydraulic cylinder via a pivot arm connected to a piston rod of the hydraulic cylinder. The hydraulic cylinder is vertically mounted on a drill rig. The pivot arm is rotated to a working position and raised by the hydraulic cylinder to be positioned over an impact surface of an anvil. When the drive hammer system is positioned over the anvil, a shutoff valve is opened to allow fluid in the hydraulic cylinder to be exhausted.
[0019] In this state, by actuation of a motor mounted on the cylindrical housing, a sprocket is rotated to cause a chain to be rotated clockwise. Lifting lugs on the chain are raised along a slot axially formed at the cylindrical housing by the rotation of the sprocket. At this point, the lug comes into contact with a lower end of a hammer received in the housing. As the lug pushes the hammer up, the hammer is gradually distanced from the anvil.
[0020] When the lug reaches the sprocket and begins to move outwardly, the lug moves from under the hammer, permitting the hammer to free fall until it strikes the impact surface of the anvil. By the striking action of the hammer against the anvil, a sampler penetrates the soil, thereby allowing the anvil to be lowered. At this point, the cylindrical housing free falls by the penetration depth of the sampler, and thus is placed on a flange of a drill rod, thereby maintaining a drop height at a certain value.
[0021] The drive hammer system itself is lowered by the penetration depth after every blow so as to maintain the drop height of the hammer at a certain value. However, since the drive hammer system strikes the flange of the drill rod soon after blows from the hammer (i.e. secondary blows), the sampler further penetrates the soil.
[0022] In addition, since the hammer is adapted to be raised by the lifting lug of the turning chain and to fall by release from the lug, the hammer may be raised to a position higher than the specified height by being struck by the lug in the course of turning when the chain is rotated at high speed.
[0023] In addition to this, it is troublesome to measure a penetration depth of the sampler by blows of the hammer by an additional measuring device.
[0024] Accordingly, this drive hammer system is not able to assure accuracy and reliability of an N value.
SUMMARY OF THE INVENTION
[0025] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide an automatic hammer system for use in a standard penetration test, which is adapted to enable a hammer to be raised and to fall automatically, and which is adapted to maintain a drop height of a hammer at a certain value, regardless of a penetration depth of a sampler.
[0026] Another object of the present invention is to provide an automatic hammer system for use in a standard penetration test, which is able to minimize loss of impact energy of a hammer caused by frictional contacts between associated components, and which is adapted to reliably prevent secondary blows against an anvil, thereby permitting the anvil to always be applied with a specified impact energy.
[0027] A further object of the present invention is to provide an automatic hammer system for use in a standard penetration test, which is adapted to automatically carry out a series of test procedures for counting the number of blows by a hammer and a penetration depth of a sampler according to the number of blows, thereby affording a precise N value.
[0028] In order to accomplish the above object, the present invention provides an automatic hammer system for a standard penetration test, comprising: a first vertical hydraulic cylinder rotatably coupled to boring equipment; a cylindrical housing positioned to be parallel to the first hydraulic cylinder and coupled thereto, the cylindrical housing being connected to a piston rod of the first hydraulic cylinder and adapted to receive therein an anvil of a drill rod, wherein the drill rod is provided at its lower end with a sampler to be inserted in a boring hole of the soil; a cylindrical hammer with a blind lower end, which is movably received in the housing to be disposed over the anvil; a holding assembly received in the hammer and adapted to hold the hammer at its lower dead point and to release the hammer at its upper dead point to allow the hammer to fall; a second hydraulic cylinder concentrically coupled to an upper end of the housing and adapted to raise and lower the holding assembly; means for limiting a lifting height of the hammer, which is received in the housing to be disposed over the hammer and integrally coupled to the holding assembly with a spacing therebetween, the limiting means being raised and lowered within a certain range; means for counting the number of blows of the hammer against the anvil; means for measuring a penetration depth of the sampler by blows of the hammer; and a control unit for carrying out control of the striking action of the hammer and calculation of an N value according to data obtained by the counting means and the measuring means, and for carrying out record and display of test results.
[0029] According to an aspect of the present invention, the holding assembly includes a cylindrical casing which is radially provided at its wall with a plurality of fitting slots at a certain angular spacing, a plurality of holding blocks slidably fitted in the fitting slots of the casing and adapted to selectively press an inner surface of the hammer, and a pusher unit received in the casing and connected to the piston rod of the second hydraulic cylinder, the pusher unit being adapted to outwardly push or release the holding blocks in the course of axial movement.
[0030] The pusher unit is adapted to outwardly push and release the holding blocks when the pusher unit is further lowered and raised after the limiting means is stopped.
[0031] According to another aspect of the present invention, the counting means comprises a detection slot formed at an upper portion of the housing, and a first sensor mounted on the plunger to detect the detection slot to count the number of blows by the hammer.
[0032] According to a further aspect of the present invention, the measuring means comprises a plurality of protrusions axially formed along an outer surface of the hammer at a certain pitch, and a second sensor mounted on a wall of the housing to detect the number of protrusions passed over the second sensor during every lifting motion, thereby enabling a penetration depth to be obtained from the number of protrusions.
[0033] According to the present invention, the holding assembly is actuated to outwardly press an inner surface of the elongated cylindrical hammer, thereby firmly holding the hammer. The holding assembly engaging the hammer is raised by the second hydraulic cylinder and then releases the hammer to fall freely. After a blow by the hammer, since the holding assembly holds the hammer at a position which is higher than the previous holding position by a penetration depth of the previous blow, a drop height of the hammer is uniformly maintained for every blow, regardless of a penetration depth of the hammer.
[0034] Furthermore, since the hammer is adapted to be raised to a certain height and then to fall therefrom without lowering displacement of the hammer system itself, it is possible to reliably prevent secondary blows caused by lowering of a conventional hammer system. Therefore, the anvil can always be applied with specified impact energy.
[0035] In addition, since the number of blows by the hammer and penetration depths according to the number of blows are automatically calculated and accumulated, an N value can be precisely obtained, thereby affording improvements in reliability of test results and convenience in testing.
[0036] Therefore, the automatic hammer system for a standard penetration test according to the present invention can contribute to improvements in the accuracy, reliability and convenience of a standard penetration test.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0038] [0038]FIG. 1 is a perspective view of a conventional hammer system for use in a standard penetration test;
[0039] [0039]FIG. 2 is a perspective view of an automatic hammer system for a standard penetration test according to the present invention, which is mounted on a boring machine;
[0040] [0040]FIG. 3 is a front elevation view of the automatic hammer system for a standard penetration test according to the present invention;
[0041] [0041]FIG. 4 is a side elevation view taken along line IV-IV of FIG. 3;
[0042] [0042]FIG. 5 is a cross-sectional view taken along line V-V of FIG.
[0043] [0043]FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 4;
[0044] [0044]FIG. 7 is an enlarged cross-sectional view of a holding assembly according to the present invention;
[0045] [0045]FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. 7;
[0046] [0046]FIG. 9 is an enlarged cross-sectional view of means for limiting a stroke of a hammer according to the present invention;
[0047] [0047]FIGS. 10A to 10 D are cross-sectional views showing a holding operation of the holding assembly according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0048] This invention will be described in further detail by way of example with reference to the accompanying drawings.
[0049] As shown in FIGS. 2 to 6 , an automatic hammer system for a standard penetration test according to the present invention comprises a first hydraulic cylinder 10 , a cylindrical housing 20 adapted to be raised and lowered by the first hydraulic cylinder 10 , a hammer 30 received in the housing 20 to be raised and lowered to impact against an anvil 91 coupled to a drill rod 90 , a holding assembly 40 adapted to raise the hammer 30 by gripping action and to allow the hammer 30 to fall, a second hydraulic cylinder 50 adapted to raise and lower the holding assembly 40 , means 60 for limiting a lifting height of the hammer 30 to a certain height, means 70 for counting the number of blows of the hammer 30 , means 80 for measuring a penetration depth of a sampler by blows of the hammer 30 , and a control unit for controlling striking action of the hammer 30 and for recording and displaying test results such as N values.
[0050] As shown in FIG. 2, the first hydraulic cylinder 10 is disposed parallel to a vertical support shaft 110 , and rotatably coupled to the support shaft 110 via an arm bracket 120 . The support shaft 110 is mounted on boring equipment 100 , which is adapted to excavate boring holes (not shown) to be used in a soil test.
[0051] The housing 20 is coupled to the first hydraulic cylinder 10 by a carrier 21 such that the housing 20 is disposed parallel to the first hydraulic cylinder 10 and is raised and lowered with respect to the first hydraulic cylinder 10 . The carrier 21 is slidably inserted at its one end on the first hydraulic cylinder 10 , and fixedly coupled at its other end to the housing 20 .
[0052] A support rod 22 is vertically positioned and fixed to the carrier 21 at its lower end. The upper end of the support rod 22 is connected to an upper free end of a piston rod 11 of the first hydraulic cylinder 10 by a connector 23 .
[0053] The anvil 91 coupled to the upper end of the drill rod 90 is slidably received in the housing 20 and normally disposed at its lower portion.
[0054] The hammer 30 is shaped as an elongated cylindrical form, and is movably received in the housing 20 . The hammer 30 is comprised of a striking part 31 positioned at its lower portion to provide blow to the anvil 91 , and an elongated cylindrical holding part 32 disposed on the striking part 31 and opened at its upper end to receive the holding assembly 40 .
[0055] The holding part 32 of the hammer 30 is sized to be longer than a sum of a penetration depth (15 cm) of a sampler (not shown) and a penetration depth (30 cm) of the sampler corresponding to an N value, in which the penetration depth (15 cm) of the sampler is believed to be a depth corresponding to preliminary blows.
[0056] As illustrated in FIGS. 7 and 8, the holding assembly 40 includes a casing which is movably received in the holding part 32 of the hammer 30 , a pair of push blocks 42 adapted to radially and outwardly press and release an inner surface of the holding part 32 , and a pusher unit 43 adapted to actuate the push blocks 42 .
[0057] The casing 41 is comprised of a cylindrical body with a blind lower end in which the pusher unit 43 is operatively received. The casing 41 is provided at its upper end with a cap 44 to limit an upward movement of the pusher unit 43 and to prevent separation of the pusher unit 43 . The casing 41 is formed with a pair of fitting slots 41 a at diametrically opposite sides in which the pair of push blocks 42 are fitted.
[0058] The pair of push blocks 42 are slidably inserted in the pair of fitting slots 41 a of the casing 41 , so that the outer ends of the push blocks 42 are selectively engaged to an inner surface of the holding part 32 of the hammer 30 . Each of the push blocks 42 is sized to be longer than a wall thickness of the casing 41 so that an inner end of the push block 42 is slightly and inwardly protruded from an inner surface of the casing 41 .
[0059] The pusher unit 43 includes an actuating rod 45 slidably received in the casing 41 , a drop head 46 which is fitted in a hole formed at the lower end of the casing 41 to be axially slid, and a dog 47 pivotally connected to a lower end of the actuating rod 45 by a hinge pin 47 a.
[0060] The actuating rod 45 is connected to a piston rod 51 of the second hydraulic cylinder 50 , and is raised and lowered in the casing 41 .
[0061] The drop head 46 is fitted in the hole 41 b formed at the lower end of the casing 41 . The drop head 46 is provided at its outer surface with a flange 46 a , so that the drop head 46 is hung on the lower end of the casing 41 and properly protruded upwardly and downwardly to open the dog 47 .
[0062] The dog 47 is elastically biased by a torsion spring (not shown) in a closing direction, and is adapted to be opened by a lowering motion of the actuating rod 45 to receive the drop head 46 at its mouth, thereby pushing the push blocks 42 outwardly.
[0063] The second hydraulic cylinder 50 is concentrically connected to an upper end of the housing 20 . The piston rod 51 of the second hydraulic cylinder 50 is received in the housing 20 , and is connected to the actuating rod 45 of the pusher unit 43 via a connecting pipe 48 .
[0064] As shown in FIG. 9, the limiting means 60 includes a plunger unit 61 received in the housing to be positioned over the hammer 30 and to be raised and lowered in a certain range, and a pair of guide slots 62 , which are axially formed at the wall of the housing 20 to face each other.
[0065] The plunger unit 61 comprises a bush-type body 64 which includes a flange 64 a having an external diameter corresponding to an internal diameter of the housing 20 and a guide hole 64 b formed at its center, a connector 65 slidably fitted in the guide hole 64 b of the body 64 to connect the piston rod 51 of the second hydraulic cylinder 50 to the connecting pipe 48 , and a pair of guide protrusions 63 formed on an outer surface of the bush-type body 64 and slidably fitted in the corresponding guide slots 62 .
[0066] The body 64 of the plunger unit 61 is integrally coupled to the casing 41 of the holding assembly 40 by a joint pipe 66 , and is thus raised and lowered together with the holding assembly 40 with a certain spacing therebetween. The body 64 of the plunger unit 61 is adapted to be raised and lowered in a height range corresponding a drop height (75 cm) specified in the standard penetration test.
[0067] The body 64 of the plunger unit 61 is securely connected to the casing 41 of the holding assembly 40 by means of a plurality of connecting rods 67 .
[0068] The housing 20 is provided at its outer surface with a pair of upper stoppers 68 a and a pair of lower stoppers 68 b such that the upper stoppers 68 a are axially spaced from the lower stoppers 68 b , so as to more stably limit axial movement of the plunger unit 61 . The pair of upper stoppers 68 a and the pair of lower stoppers 68 b are disposed at positions corresponding to the guide slots 62 of the housing 20 , which come into contact with the guide protrusions 63 of the plunger unit 61 .
[0069] The spacing defined between the upper stoppers 68 a and the lower stoppers 68 b is set to equal to the drop height specified in the standard penetration test, and is also set to be smaller than a stroke length of the second hydraulic cylinder 50 , so that the pusher unit 43 can be raised and lowered in the casing 41 .
[0070] The means 70 for counting the number of blows comprises a detection slot 71 formed at an upper portion of the housing 20 , and a first sensor 72 mounted on an upper end of the connecting rod 67 projected from the plunger unit 61 to detect the detection slot 71 during axial movement of the plunger unit 61 .
[0071] The means 80 for measuring a penetration depth of the sampler, comprises a plurality of annular protrusions 81 formed on an outer surface of the hammer 30 at a certain pitch, and a second sensor 82 mounted on a wall of the housing 20 to detect the annular protrusions 81 .
[0072] The control unit stores various data such as a pitch of the annular protrusions 81 required for a standard penetration test, and controls the action of the hammer 30 .
[0073] An operation of the automatic hammer system for a standard penetration test according to the present invention will now be described with reference to FIGS. 10 a to 10 d.
[0074] After a boring operation by the boring equipment 100 is carried out to form a boring hole to a target depth, the drill rod 90 , which is connected to the sampler at its lower end, is coupled to an anvil 91 , and then inserted into the boring hole. Subsequently, the automatic hammer system is rotated about the support shaft 110 of the boring equipment 100 until the automatic hammer system is precisely positioned over the boring hole, as indicated by dotted lines in FIG. 2.
[0075] The housing 20 is raised or lowered by activation of the first hydraulic cylinder 10 , so that the hammer 30 received in the housing 20 is placed on the anvil 91 , as shown in FIG. 10A. The holding assembly 40 is then controlled to be positioned at a lower portion of the holding part 32 of the hammer 30 . At this point, the plunger unit 61 of the limiting assembly 60 is disposed at the lowermost position and comes into contact with the lower stoppers 68 b.
[0076] In this state, since the drop head 46 of the holding assembly 40 is hung on the lower end of the casing 41 , and is not bitten by the dog 47 , the push blocks 42 are not applied with pressing force, so that the hammer 30 is free of engagement with any component.
[0077] Thereafter, as the hammer system is driven, the piston rod 51 is lowered by actuation of the second hydraulic cylinder 50 . Consequently, the actuating rod 45 of the pusher assembly 43 , which is coupled to the piston rod 51 via the connecting pipe 48 , is lowered in the casing 41 .
[0078] Consequently, the dog 47 pivotally coupled to the lower end of the actuating rod 45 is engaged to the top of the drop head 46 hung on the lower end of the casing 41 , and thus opened, followed by biting the drop head 46 by elastic force of the torsion spring, as shown in FIG. 10B.
[0079] After the drop head 46 is bitten by the dog 47 , the piston rod 51 of the second hydraulic cylinder 50 is raised, as shown in FIG. 10C. In this state, since the drop head 46 is merely hung on the hole 41 b of the casing 41 , the drop head 46 is also raised together with the actuating rod 45 in a state of being bitten by the dog 47 .
[0080] As the dog 47 is raised, the push blocks 42 are radially and outwardly pushed by the opened dog 47 , and come into close contact with the inner surface of the hammer 30 , as indicated by a phantom line in FIG. 8. Accordingly, the hammer 30 is integrally coupled to the holding assembly 40 via the push blocks 42 , and then raised in the housing 20 together with the piston rod 51 .
[0081] At this point, since the plunger unit 61 disposed over the hammer 30 is connected to the casing 41 of the holding assembly 40 via the joint pipe 66 , the plunger unit 61 is also raised therewith.
[0082] When the guide protrusions 63 of the plunger unit 61 60 come into contact with the upper stoppers 68 a , the upward movement of the plunger unit 61 is stopped, and the holding assembly 40 connected to the plunger unit 61 is also stopped at the upper dead point.
[0083] When the plunge unit 61 is positioned at the upper dead point, the first sensor 72 of the count means 70 mounted on the connecting rod 67 is positioned to face the detection slot 71 of the housing 20 , thereby detecting the detection slot 71 . The detection signal is sent to the control unit, so that the control unit counts the number of detections.
[0084] At the same time, the second sensor 82 mounted on the wall of the housing 20 detects the number of the annular protrusions 81 passed over the second sensor 82 , and sends a signal corresponding to the number to the control unit. More specifically, the second sensor 82 detects the annular protrusions 81 which pass over the sensor 82 during one lifting action of the hammer 30 , and send a signal corresponding to the number of the protrusions 81 to the control unit.
[0085] Since a stroke length of the piston rod 51 of the second hydraulic cylinder 50 is set to be longer than the spacing between the upper stoppers 68 a and the lower stoppers 68 b , the piston rod 51 is further raised even after the guide protrusions 63 of the plunger unit 61 have been caught by the upper stoppers 68 a.
[0086] More specifically, since the piston rod 51 passes through the connector 65 slidably fitted in the guide hole 64 b of the plunger unit 61 , and is connected to the actuating rod 45 of the pusher unit 43 via the connecting pipe 48 , the piston rod 51 can be further raised until the actuating rod 45 is raised to the top of the casing 41 and thus caught by the cap 44 , as shown in FIG. 10D.
[0087] In this way, since the actuating rod 45 is further raised after the upward movement of the hammer 30 is stopped, the dog 47 in the casing 41 is raised with respect to the push blocks 42 , thereby allowing the drop head 46 to be released from the dog 47 .
[0088] At this point, since the pressing force applied to the push blocks 42 which are in state of pressing the inner surface of the hammer 30 radially and outwardly is removed, the hammer 30 falls by its own weight and thus impacts against the anvil 91 , thereby causing the sampler coupled to the drill rod 90 to penetrate the soil.
[0089] After the anvil 91 is applied with a blow by the hammer 5 , the piston rod 51 of the second hydraulic cylinder 50 is lowered again, so that the holding assembly 40 is lowered together with the plunger unit 61 .
[0090] Subsequently, when the guide protrusions 63 of the plunger unit 61 are caught by the lower stoppers 68 b , the plunger unit 61 and the casing 41 of the holding assembly 40 are stopped but the actuating rod 45 of the pusher unit 43 is further lowered because the actuating rod 45 is connected to the piston rod 51 of the second hydraulic cylinder 50 via the connector 65 of the plunger unit 61 and the connecting pipe 48 .
[0091] Consequently, the dog 47 is relatively lowered in the casing 41 with respect to the push blocks 42 , as shown in FIG. 10A. Thereafter, the dog 47 is opened by forcible engagement with the drop head 46 and thus bites the drop head 46 . In this state, as the piston rod 51 is raised, the push blocks 42 are outwardly pushed by the opened dog 47 with a larger width, thereby causing the hammer 30 to be firmly held by the push blocks 42 .
[0092] At this point, since the inner surface of the hammer 30 is pressed by the push blocks 42 at a position which is disposed to be higher than the previous pressed position by a distance corresponding to a penetration depth by the previous blow, drop heights of the hammer 30 can be maintained at a predetermined value for every blow, regardless of a penetration depth of the sampler.
[0093] In other words, since the hammer 30 is held by engagement of its inner surface and the push blocks 42 , and a lifting distance of the holding assembly 40 is defined by the upper and lower stoppers 68 a and 68 b , a substantial lifting height of the hammer 30 is uniformly maintained even though the hammer 30 is lowered with respect to the hammer system, with only a variation in a holding position of the hammer 30 to which the push blocks 42 are engaged.
[0094] Therefore, the automatic hammer system according to the present invention can basically prevent secondary blows generated by lowering of an overall hammer apparatus caused by increase of penetration depth, as in a conventional system.
[0095] When the hammer 30 is raised again by the holding assembly 40 as the piston rod 51 of the second hydraulic cylinder 50 is raised, the second sensor 82 mounted on the wall of the housing 20 detects the annular protrusions 81 formed on the outer surface of the hammer 30 which pass over the second sensor 82 , and outputs a signal corresponding to the number of the annular protrusions 81 .
[0096] At this point, the control unit calculates the number of protrusions corresponding to a penetration depth corresponding to one blow by subtracting the current number of the protrusions 81 from the previous number of the protrusions 81 , and then finally calculates the penetration depth corresponding to one blow by multiplying the calculated number of protrusions by a pitch of the protrusions.
[0097] By accumulating penetration depths obtained in every blow in the above manner, it is possible to conveniently obtain a precise N value.
[0098] As described above, the present invention provides an automatic hammer system for a standard penetration test, which enables drop heights of its hammer to be uniformly maintained for every blow, regardless of a penetration depth of the hammer, since the hammer is held at its inner surface by a holding assembly adapted to be raised and lowered in a predetermined distance range.
[0099] Furthermore, since the hammer is adapted to be raised to a certain height and then to fall therefrom without lowering displacement of the hammer system, it is possible to reliably prevent secondary blows caused by lowering of a conventional hammer system.
[0100] In addition, since the number of blows by the hammer and penetration depths according to the number of blows are automatically calculated and accumulated, an N value can be precisely obtained.
[0101] Therefore, the automatic hammer system for a standard penetration test according to the present invention can contribute to improvements in accuracy, reliability and convenience of a standard penetration test.
[0102] Although a preferred embodiment of the present invention has been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
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A hammer system for automatically carrying out a standard penetration test is disclosed. A cylindrical housing, in which an anvil coupled to a drill rod is received, is supported by a first hydraulic cylinder coupled to boring equipment. A cylindrical hammer is received in the housing. The hammer includes a holding assembly therein, which selectively holds and raises the hammer by a second hydraulic cylinder. Means for limiting a stroke of the hammer is spacedly connected to the holding assembly to be raised and lowered therewith. The limiting means includes a first sensor to detect a slot formed at the housing when the hammer is raised, thereby counting the number of blows. The hammer includes a plurality of protrusions on its outer surface. A wall of the housing includes a second sensor to detect the number of protrusions passed over the second sensor when the hammer is raised, thereby calculating a penetration depth from a difference between the numbers of protrusions detected for two continuous blows. Since the hammer system uniformly maintains drop heights of the hammer without lowering displacement of the hammer system itself, it is possible to prevent secondary blows. The hammer system precisely measures the number of blows and a penetration depth by continuous test procedures.
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RELATED APPLICATIONS
[0001] This application claims the benefit of provisional application Ser. No. 61/221,963 filed on Jun. 30, 2009.
FIELD OF THE INVENTION
[0002] The invention relates to game animal scouting cameras and, more particularly, to user interfaces and corresponding methods of programming that are incorporated into game animal scouting cameras.
BACKGROUND OF THE INVENTION
[0003] Game animal observation for recreation and/or for scouting in association with hunting activities is growing increasingly popular. Game animal observation or scouting activities can include implementation of scouting cameras for taking photographs, video footage, or other recordings. Use of scouting cameras for game animal observation or scouting is generally known.
[0004] Scouting cameras for scouting potential hunting areas and determining game patterns, particularly without disturbing animal activity, are generally well known in the art. Typically, the apparatus includes a film, digital or video camera and a passive infrared sensor (e.g., a motion/heat sensor) that is adapted to sense movement and, in response, activate the camera focused on the area in which the sensor detects movement. Oftentimes, these devices include a delay timer with multiple settings to match specific conditions or locations, thus eliminating unwanted multiple exposures or other non-desired events. Moreover, such apparatus preferably includes high/low sensitivity settings to allow adjustment of the camera's effective range in order to photograph or record game at a desired distance.
[0005] Known scouting cameras are set up or programmed by the user, typically, using relatively complex user interfaces and/or complex procedures. Many such scouting camera user interfaces include keypads that have five or more keys which are used to navigate through menus shown on a display and then set or define various operational parameters or values. With numerous menus to navigate through and numerous parameters or values to define, setting up and programming known scouting cameras can be confusing and can take a substantial amount of time. Setting up and programming some known scouting cameras is so complex that users take their operator's or instruction manuals with them to the field to use as references to guide them through such procedures. If such users are, for whatever reason, without their manuals, then they may experience great difficulty in setting up or programming their scouting cameras.
OBJECTS OF THE INVENTION
[0006] It is the object of the present invention to provide a scouting camera user interface which addresses these shortcomings by overcoming the aforesaid problems of the prior art. It is an object of the present invention to provide a scouting camera user interface which is easy to use, compared to known scouting cameras, even in the field. It is a further object of the present invention to provide a scouting camera user interface which requires relatively few manipulations to program, activate, and control a scouting camera. Another object of the innovative scouting camera user interface is to enable a scouting camera to be fully programmable for numerous functions without requiring extensive keypad manipulation or manipulating numerous DIP (dual in-line package) switches. Yet another object of the present invention is to provide a scouting camera user interface with a multiple-stage switch, e.g., a rotary switch, and one or more operation keys.
SUMMARY OF THE INVENTION
[0007] The present invention is a scouting camera which includes (i) a processing system having an operating system and a memory device and (ii) a user interface operably connected to the processing system and including: a visual display; at least one operation key for inputting user commands; and a multiple-stage manual switch that is moved to multiple alignment positions to control multiple camera functions during a camera setup procedure.
[0008] In some preferred embodiments of the innovative scouting camera, the multiple-stage manual switch defines a first range controlling a first category of camera functions and a second range controlling a second, different category of camera functions. In some such embodiments, the at least one operation key is used in combination with the multiple-stage manual switch to define a value that corresponds to a setting within one of the first and second categories of camera functions.
[0009] In some preferred embodiments, the multiple-stage manual switch alone is used to define a value that corresponds to a setting within the other one of the first and second categories of camera functions.
[0010] In other preferred embodiments, the first category of camera functions includes at least one of time and date settings, and the second category of camera functions includes picture-taking frequency settings. In some of these embodiments, the multiple-stage manual switch further defines a switch position corresponding to at least one of a test mode and a power-off setting.
[0011] In additional preferred embodiments of the innovative scouting camera, the at least one operation key includes a first operation key and a second operation key and the multiple-stage manual switch defines (a) a time position for setting a time value, (b) a date position for setting month and day values, and (c) a year position for setting a year value, at least one position of which is displayable on the visual display.
[0012] In other preferred embodiments, when the multiple-stage manual switch is located at the time position, the first operation key manipulates an hour value and the second operation key manipulates a minute value. In other such embodiments, when the multiple-stage manual switch is located at the date position, the first operation key manipulates a month value and the second operation key manipulates a day value. And yet other such embodiments, when the multiple-stage manual switch is located at the year position, manipulating the first operation key increases a year value displayed on the visual display and manipulating the second operation key decreases a year value.
[0013] In highly-preferred embodiments of the innovative scouting camera, the manual switch is a rotary switch.
[0014] The present invention also includes a method of operating a scouting camera, and such method includes performing an initial setup of the scouting camera by (a) determining a setting to define a value therefor, (b) aligning a multiple-stage rotary switch to a position that corresponds to the setting, (c) manipulating an operation key to define the value; and (d) activating the scouting camera. In some preferred embodiments of the innovative method, the scouting camera is automatically activated after performing the initial setup. Other preferred embodiments of the operation of a scouting camera further include determining a second setting to define a second value therefor and defining the second value by aligning the multiple-stage rotary switch to a position that corresponds to a desired value. In some such preferred embodiments, the second value is defined without manipulating the operation key.
[0015] Other preferred embodiments of the innovative method of operating a scouting camera comprise (a) rotating a multiple-stage rotary switch from a position corresponding to a power-off setting to a position within a first rotational range for controlling a first category of camera functions; (b) defining a first setting value within the first category of camera functions by manipulating an operation key; and (c) defining a second setting value within a second category of camera functions by rotating the multiple-stage rotary switch to a position within a second rotational range. In some of these preferred embodiments, the first category of camera functions includes time and date settings and the second category of camera functions includes picture-taking frequency settings. Other such embodiments further include (i) moving the multiple-stage rotary switch to a first discrete position within the first rotational range; (ii) manipulating the operation key to set a first time and/or date value; (iii) moving the multiple-stage rotary switch to a second discrete position within the first rotational range; (iv) manipulating the operation key to set a second time and/or date value; and (v) moving the multiple-stage rotary switch to a discrete position within the second rotational range to set a picture-taking frequency value.
[0016] In yet other preferred embodiments of the innovative method for operating a scouting camera, setting the picture-taking frequency value is performed without manipulating the operation key.
[0017] In additional embodiments of the innovative method, the scouting camera includes first and second operation keys and the multiple-stage rotary switch defining (a) a time position for setting a time value, (b) a date position for setting month and day values, and (c) a year position for setting a year value, at least one position of which is displayable on the visual display. In some of these preferred embodiments, the method further includes moving the multiple-stage rotary switch to a time position, manipulating the first operation key to set an hour value, and manipulating the second operation key to set a minute value. In other of these preferred embodiments, the method includes moving the multiple-stage rotary switch to a date position, manipulating the first operation key to set a month value, and manipulating the second operation key to set a day value. And in yet other of these embodiments, the method includes moving the multiple-stage rotary switch to a year position, manipulating the first operation key to increase a year value, and manipulating the second operation key to decrease a year value.
[0018] These and other aspects and objects of the present invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating preferred embodiments of the present invention, is given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a perspective view of a first embodiment of a scouting camera.
[0020] FIG. 2 is a front elevational view of a programming interface of the scouting camera of FIG. 1 .
[0021] FIG. 3 is a close-up front elevational view of the user interface of FIG. 2 .
[0022] FIG. 4 is a flowchart illustrating a method of using the programming interface of the preferred embodiments.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0023] With initial reference to FIGS. 1 and 2 , a scouting camera 5 is shown. Scouting camera 5 includes a processing system 7 that includes various known system resources such as, for example, a memory device, a processor, and an operating system (not shown specifically but in general) communicating with each other and configured to perform the desired functions of scouting camera 5 . The scouting camera 5 further includes a main body 10 and a cover 30 that are joined together with a hinge 40 at a top portion of the main body 10 . At a bottom portion of the main body 10 , a lock assembly 50 is provided which includes a thumbscrew for temporarily holding the cover 30 against the main body 10 and a lock receptacle to receive a lock when securing the cover 30 against the main body 10 .
[0024] Main body 10 is a box-like enclosure that has a back wall 11 , multiple sidewalls 12 , 13 extending therefrom, and a front wall 15 . Front wall 15 holds an infrared illuminator 14 , a camera window 16 , and a sensor, such as a heat-in-motion sensor 18 , vertically aligned with each other and extending down the middle of the front wall 15 . Multiple LEDs (light emitting diodes) 20 , 22 can be provided on the front wall 15 and can be configured to indicate feature or other statuses of scouting camera 5 or convey various other information to a user. A pair of battery bays 24 , 26 are parallel to each other sitting adjacent the sidewalls 12 , 13 and open into the main body 10 so that the back wall 11 serves as the back of the battery bays 24 , 26 and the sidewalls 12 , 13 define outer lateral walls of the battery bays 24 , 26 . Each of the battery bays 24 , 26 has a pair of flanges 25 that extend outwardly from the front wall and across part of the opening of the bays 24 , 26 to capture and retain batteries therein. A memory card slot 28 communicates with the processing system 7 and is provided near one of the battery bays 24 , 26 .
[0025] Cover 30 flips open and closed by pivoting about a hinge pin of the hinge 40 , which is preferably configured to selectively hold the cover 30 in one or more open positions. The cover 30 has various openings that align with the IR illuminator 14 , camera window 16 , and heat-in-motion sensor 18 allowing such components to operate when the cover 30 is in the closed position, overlying the main body 10 . When the cover 30 is in an open position, a user interface 100 is readily accessible to a user.
[0026] Referring now to FIGS. 2 and 3 , user interface 100 is configured to perform numerous setup and programming functions by way of few user input devices and by using few steps. For example, the user interface 100 includes a visual display 110 , a multiple-stage manually operable switch, such as a rotary switch 120 , and a pair of operation keys “A” and “B”. (In FIG. 3 , the labels “A” and “B” are associated with the two square keys located directly above such labels, respectively.) Visual display 110 can be an LCD (liquid crystal display) or other suitable known display device that communicates with the processing system 7 and conveys system status and/or other use-related information to the user.
[0027] Referring now to FIG. 3 , multiple-stage rotary switch 120 has a base 122 and an arm 124 that visually indicates where the multiple-stage rotary switch 120 is pointing or what it is aligned with at any given time. Multiple stage rotary switch 120 is rotatable about an entire 360-degree range of circular movement. Within the full range of circular or rotational movement, the multiple-stage rotary switch 120 defines multiple rotational ranges that account for portions of the full rotational range. For example, a SET-range 130 defines a first rotational range for controlling a first category of camera functions, and an ARMED-range 140 defines a second rotational range for controlling a second category of camera functions.
[0028] SET-range 130 provides a control mechanism for a clock or calendar feature, allowing processing system 7 to, for example, time and date stamp photos when they are taken. SET-range 130 includes three distinct positions, namely, Time position 132 , Date position 134 , and Year position 136 . ARMED-range 140 provides a control mechanism for picture-taking frequency, by controlling the scouting camera's five dwell times or periods of time that it waits or delays before taking another picture. ARMED-range 140 includes five distinct positions, namely, 30 s position 142 , 1 m position 143 , 5 m position 144 , 15 m position 145 , and 30 m position 146 which correspond to dwell times of thirty seconds, one minute, 5 minutes, fifteen minutes, and thirty minutes, respectively. The particular positions, number of positions, and types of camera functions that correspond to such positions are merely exemplary and non-limiting, noting that other camera functions can be controlled by way of multiple-stage rotary switch 120 , depending on the particular desired end-use configuration of scouting camera 5 .
[0029] Still referring to FIG. 3 , in addition to the SET-range 130 and ARMED-range 140 , multiple-stage rotary switch 120 can have other positions defined within its full rotational range. For example, Test position 150 and Off position 155 can be provided between the SET-range 130 and ARMED-range 140 , optionally elsewhere within the full rotational range of the multiple-stage rotary switch 120 . Operation keys “A” and “B” cooperate with the multiple-stage rotary switch 120 for controlling at least some of the functions of scouting camera 5 and/or inputting and defining various values; this portion of operation is described in greater detail elsewhere herein.
[0030] Referring now to FIGS. 1-3 , in light of the above, to use the scouting camera 5 , it is first mounted to a tree or other mounting substrate by way of a screw, strap, or other suitable hardware. Preferably, scouting camera 5 is mounted about three feet above the ground and about ten feet to fifteen feet, optionally up to about 50 feet, from a particular area where games animals are expected to be found. The multiple-stage rotary switch 120 is turned to the Off position 155 , and batteries are installed into the battery bays 24 , 26 . Scouting camera 5 senses a charge or power value of the batteries and, if the batteries are low on power, then the same is conveyed to the user by, for example, showing a low-battery icon (not shown) on the visual display 110 . In some embodiments, after batteries are installed in scouting camera 5 , a series of numbers is shown on the visual display 110 , revealing product and software information such as hardware and software version numbers, and then the visual display 110 powers down and scouting camera 5 remains off. A memory card (not shown) is inserted into the memory card slot 28 of scouting camera 5 , and a setup procedure can begin by way of the user interface 100 .
[0031] Referring again to FIG. 3 , as part of the setup procedure, a preliminary test can be performed to check or confirm a detection zone of the scouting camera 5 . The multiple-stage rotary switch 120 is moved to the Test position 150 . Cover 30 is closed and then secured shut with the thumbscrew of the lock assembly 50 . The user walks back and forth in front of scouting camera 5 , and an LED 20 is illuminated, visible through an opening of the cover 30 , when the user is detected by the scouting camera 5 .
[0032] Still referring to FIG. 3 , the setup continues by using the SET-range 130 for setting various time and date values. Namely, multiple-stage rotary switch 120 is moved to the Time position 132 . When switch 120 is in the Time position 132 , pressing the “A” operation key manipulates or sets an hour value and pressing the “B” operation key manipulates or sets a minute value. Next, multiple-stage rotary switch 120 is moved to the Date position 134 . When switch 120 is in the Date position 134 , pressing the “A” operation key manipulates or sets a month value and pressing the “B” operation key manipulates or sets a day value. Multiple-stage rotary switch 120 is then moved to the Year position 136 . When switch 120 is in the Year position 136 , pressing the “A” operation key decreases the year value and pressing the “B” operation key increases the year value.
[0033] Still referring to FIG. 3 , the setup continues by using ARMED-range 140 for setting a picture-taking frequency or dwell time value for scouting camera 5 . This can be done without manipulating the operation keys “A” and “B”, but instead by only using the multiple-stage rotary switch 120 . The user decides which dwell time to implement and then moves multiple-stage rotary switch 120 to the corresponding one of the “30 s” position 142 , “1 m” position 143 , “5 m” position 144 , and “15 m” position 145 , and “30 m” position 146 .
[0034] The dwell times can be selected based on the particular environment or habitat in which scouting camera 5 is installed and the type of animal activity that is expected at such location, in order to minimize a likelihood of taking multiple pictures of the same game animal(s). For example, 30 s position 142 establishes a relatively short dwell time of thirty seconds before the scouting camera 5 can take a subsequent picture after taking a first picture. A short dwell time of 30 seconds can be appropriate for a game animal trail location since an animal on such a trail is likely to quickly traverse it without loitering about 1 m position 143 establishes a somewhat longer dwell time of one minute, which can be appropriate for a game animal scrape location since, for example, a buck deer typically spends a relatively short amount of time making a scrape on the ground. The longer dwell times of five, fifteen, and thirty minutes of 5 m position 144 , 15 m position 145 , and 30 m position 146 , respectively, can be appropriate for food plot or feed station locations where the game animals will likely remain for a relatively longer period of time.
[0035] After scouting camera 5 has been in use for a period of time, a user can check its picture status in the following way. Cover 30 is lifted open and the user can push either one of the operation keys “A” and “B” to temporarily suspend picture-taking function of the scouting camera 5 . When operation key “A” or “B” is released, the number of images that are stored on the memory card is shown on the visual display 110 . In some embodiments, pressing operation key “A” or “B” subsequent times will show the user yet other information on visual display 110 . Such other information includes, but is not limited to, available storage space on the memory card, time, date and year. In some embodiments, after conveying all such information to the user, pressing operation key “A” or “B” another time will put scouting camera 5 into test mode, as though multiple-stage rotary switch 120 was moved to the Test position 150 . Then after a period of inactivity, in other words, of not detecting anything in the test mode, scouting camera 5 automatically arms itself, returning it to picture-taking mode. Such period of inactivity is predetermined and can be, for example, two minutes, four minutes, five minutes, or some other time period. In some embodiments, after pressing operation key “A” or “B” a certain number of times, for example, four, five, or six times, optionally, two times in a rapid sequence, then scouting camera 5 again arms itself, returning to picture-taking mode.
[0036] Turning to FIG. 4 , a method 200 of programming a scouting camera using the above-described user interface is shown. Beginning with the switch of the user interface in Off position 155 , the user can first actuate the manually operable switch to a first position in Block 202 of FIG. 4 , and possibly to multiple positions, to set the current year, date and time. Once set, switch 120 can be used to turn scouting camera 5 off, as described above, or to arm camera 5 . To arm scouting camera 5 , the user manipulates switch 120 to a second position to define a parameter associated with scouting camera 5 use in Block 204 . For instance, camera 5 can be armed for a range of “dwell” times. As described previously, the user may want to minimize the number of shots of the same animal and can do so by making sure that scouting camera 5 cannot re-arm itself for a period of time (the dwell time). For instance, if the user selects one minute, once a subject is identified and a picture is taken, another picture cannot be taken for another minute. In sum, once the year, date and time are set on the user's camera, the user simply needs to arm scouting camera 5 with a particular dwell time to place the camera into action. This simple one-step programming of scouting camera 5 with a manually-operable switch provides far superior ease-of-use over all known scouting cameras.
[0037] While the principles of this invention have been described in connection with specific embodiments, it should be understood clearly that these descriptions are made only by way of example and are not intended to limit the scope of the invention.
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A game scouting camera including a processing system having an operating system and a memory device and a user interface operably connected to the processing system that has (a) a visual display, (b) at least one operation key for inputting user commands, and (c) a multiple-stage manual switch movable to multiple alignment positions to control multiple camera functions during a camera setup procedure.
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FIELD OF THE INVENTION
[0001] The invention relates to a thermally responsive device for activating a pressure relief device. More particularly, the invention is directed to a heat pipe capable of activating a pressure relief device by heat transfer through one of a capillary action and a fuse.
BACKGROUND SUMMARY
[0002] Presently there are a variety of pressure vessels developed for use in various applications, such as those designed to contain gases for use in fuel cells. Fuel cells have been proposed as a clean, efficient and environmentally responsible power source for electric vehicles and various other applications. One example of a fuel cell is a Proton Exchange Membrane (PEM) fuel cell. In PEM type fuel cells, hydrogen is supplied as a fuel to an anode of the fuel cell and oxygen is supplied as an oxidant to a cathode. Hydrogen is colorless, odorless, burns without producing a visible flame or radiant heat, and is difficult to contain. A common technique for storing hydrogen is in a lightweight, high pressure vessel resistant to punctures.
[0003] Traditionally such vessels are divided into four types. A Type I vessel is a metal vessel. A Type II vessel is also a metal vessel, the vessel having an outer composite shell disposed on a cylindrical section thereof. A Type III vessel consists of a liner produced from a metal such as steel and aluminum, for example, and an outer composite shell that encompasses the liner and militates against damage thereto. A Type IV vessel is substantially similar to the Type III vessel, wherein the liner is produced from a plastic. Furthermore, a conceptual Type V vessel may be developed, wherein the vessel is produced from a composite material. Each type of vessel may include a metal boss disposed therein to house a pressure relief device (PRD).
[0004] The PRD is in fluid communication with the interior of the vessel and, when actuated, vents the hydrogen in the vessel to decrease the internal pressure therein. A variety of PRD's are known, and can be actuated thermally, by pressure, or by a combination of both. In a fuel cell system, the internal pressure of the vessel rarely builds to beyond containable levels before the structural integrity of the lightweight vessel is compromised. Therefore, a fuel cell has traditionally been fitted with a thermal PRD such as the one disclosed in U.S. Pat. No. 6,006,774, hereby incorporated herein by reference in its entirety.
[0005] Typically, when the ambient air reaches a predetermined temperature, the PRD is actuated. However, where vessels are long, remote portions of the vessel insulated from the PRD can be exposed to localized heat sources without causing actuation of the PRD. Exposure to these localized heat sources can result in a rupture of the vessel. Therefore, to actuate the PRD regardless of exposure to the localized heat source, various pipes, conduits, venting lines, and fuses which actuate the PRD have been positioned along the vessel.
[0006] One such pipe is disclosed in U.S. Pat. No. 5,848,604. An elongate pressure vessel is disclosed having a single PRD located at one end. The PRD is thermally coupled to a heat pipe. The heat pipe, which extends generally parallel to an axis of the pressure vessel, conducts heat from the localized heat source at the remote location directly to the PRD. The outer casing of the pipe is made from a thermally conductive metal and is lined with a wicking material, which is capable of moving a fluid by capillary action. The inside of the pipe is filled with a vaporizable fluid. When heat is applied to the pipe, the fluid, which has permeated the wicking material, vaporizes and moves through the central core of the pipe, repeatedly condensing and vaporizing as it travels toward the PRD, until it transfers the heat to the PRD and causes the PRD to actuate.
[0007] A fuse is disclosed in U.S. Pat. No. 6,382,232. A heat responsive fuse cord is disclosed which is thermally coupled to a PRD. The PRD is in fluid communication with the pressurized contents of a vessel. When ignited, the fuse cord burns to a thermal coupler, transferring the heat to the thermal actuator of the PRD.
[0008] Alternatively, multiple PRDs may be positioned at a plurality of locations along a vessel. Each PRD communicates with the interior of the vessel via a common high pressure line extending from the boss.
[0009] Since such devices could be damaged or broken during an accident, and multiple PRDs are expensive, it would be desirable to produce a heat pipe wherein the cost thereof is minimized and the reliability thereof is maximized.
SUMMARY OF THE INVENTION
[0010] According to the present invention, a heat pipe wherein the cost thereof is minimized and the reliability thereof is maximized, has surprisingly been discovered.
[0011] In one embodiment, the heat pipe comprises a sealed casing having spaced apart ends; a porous wicking material disposed in the casing; a working fluid disposed in the casing permeating the wicking material, the working fluid adapted to transfer heat within the casing; and a fuse disposed in the casing for transporting heat within the casing upon damage to the casing causing leakage of the working fluid.
[0012] In another embodiment, the thermally responsive system comprises a pressure relief device; and a heat pipe thermally coupled to the pressure relief device, the heat pipe further comprising: a thermally conductive sealed casing having spaced apart ends; a porous wicking material disposed in the casing capable of moving a fluid by capillary action; a vaporizable working fluid disposed in the casing permeating the wicking material, the working fluid adapted to transfer heat within the casing; and a fuse disposed in the casing for transporting heat within the casing upon damage to the casing causing leakage of the working fluid, the fuse capable of being activated by at least one of oxygen and a localized heat source.
[0013] In another embodiment, the thermally responsive system for a fuel cell comprises a vessel for containing a pressurized fluid, the vessel having a first end and a second end; a pressure relief device disposed in the first end of the vessel for venting the vessel at a predetermined temperature; and a heat pipe thermally coupled to the pressure relief device extending generally parallel to the longitudinal axis of the vessel to a portion of the vessel spaced from the pressure relief device, the heat pipe adapted to transmit heat from the portion of the vessel to the pressure relief device, the heat pipe further comprising: a thermally conductive sealed casing having spaced apart ends; a porous wicking material disposed in the casing capable of moving a fluid by capillary action; a vaporizable working fluid disposed in the casing permeating the wicking material, the working fluid adapted to transfer heat within the casing; and a fuse disposed in the casing for transporting heat within the casing upon damage to the casing causing leakage of the working fluid, the fuse capable of being activated by at least one of oxygen and a localized heat source.
DESCRIPTION OF THE DRAWINGS
[0014] The above features of the invention will become readily apparent to those skilled in the art from reading the following detailed description of the invention when considered in the light of the accompanying drawings, in which:
[0015] FIG. 1 is a side elevational view partially in section of a heat pipe thermally coupled to a pressure relief device disposed in a pressure vessel according to an embodiment of the invention;
[0016] FIG. 2 is a cross-sectional view of the heat pipe illustrated in FIG. 1 , wherein the wicking material and the working fluid are disposed in the upper hemispherical section of the heat pipe and the fuse is disposed in the lower hemispherical section of the heat pipe;
[0017] FIG. 3 is a cross-sectional view of the heat pipe illustrated in FIG. 1 , according to another embodiment of the invention;
[0018] FIG. 4 is a cross-sectional view of the heat pipe illustrated in FIG. 1 , according to another embodiment of the invention; and
[0019] FIG. 5 is a schematic diagram showing heat transfer by capillary action through the heat pipe illustrated in FIG. 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] The following detailed description and appended drawings describe and illustrate various exemplary embodiments of the invention. The description and drawings serve to enable one skilled in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner.
[0021] FIG. 1 shows a thermally responsive pressure relief system for a Type IV pressure vessel 10 according to an embodiment of the invention. It is understood that the thermally responsive pressure relief system can be used with other vessel types such as a Type I, a Type II, a Type III, and a Type V, for example. The pressure vessel 10 includes a first end 12 and a second end 14 . A wall forming the vessel 10 includes a liner 16 to contain a pressurized fluid and an outer composite shell 18 that encompasses the liner 16 and militates against damage thereto. In the embodiment shown, the liner 16 is produced from a plastic material, although other materials can be used as desired.
[0022] The first end 12 of the vessel 10 is provided with a boss 20 for receiving a pressure relief device (PRD) 22 . A single PRD 22 is disposed in the boss 20 such that the PRD 22 communicates with an interior of the vessel 10 to vent the vessel 10 when subjected to temperatures above a predetermined temperature. In the embodiment shown, the PRD 22 is a thermally responsive PRD. A heat pipe 24 , thermally coupled to the PRD 22 , extends from the PRD 22 and along an exterior of the vessel 10 in a direction generally parallel to a longitudinal axis of the vessel 10 . The heat pipe 24 extends to a desired location along the vessel 10 . It is understood that the heat pipe 24 can extend to the second end 14 , if desired.
[0023] As illustrated in FIGS. 2 , 3 , and 4 , the heat pipe 24 includes an outer casing 26 . A wicking material 28 , capable of moving a fluid by capillary action, is disposed in the casing 26 . A working fluid 30 is disposed in the casing and permeates the wicking material 28 . A fuse 32 is also provided in the casing. In the embodiment shown, the fuse 32 is adapted to transfer heat generated by an exothermic reaction caused by an exposure of the fuse to at least one of oxygen and a localized heat source. An accumulation of the fuse 32 may be disposed adjacent the end 38 of the heat pipe 24 thermally coupled to the PRD 22 to increase the heat generated adjacent the PRD 22 to ensure enough heat for activation of the PRD 22 . The casing 26 is sealed to isolate the working fluid 30 from the outside environment and may be produced from any thermally conductive material such as copper, nickel, stainless steel, and the like, for example. The wicking material 28 is produced from a porous material such as a metal foam, a ceramic, and a carbon fiber, and the like, for example. The working fluid 30 can be any vaporizable fluid such as water, methanol, and the like, for example. In the embodiment shown, the heat pipe 24 has a generally circular cross-sectional shape. However, it is understood that the heat pipe 24 may have other cross-sectional shapes as desired.
[0024] FIG. 2 shows the wicking material 28 and the working fluid 30 disposed in the upper hemispherical section of the heat pipe 24 and the fuse 32 disposed in the adjacent lower hemispherical section of the heat pipe 24 . It is understood that the wicking material 28 and the working fluid 30 can be disposed in the outer section of the heat pipe 24 encapsulating the fuse 32 as shown in FIG. 3 , the inner section of the heat pipe 24 having the fuse 32 encapsulate the wicking material 28 and the working fluid 30 as shown in FIG. 4 , or elsewhere in the heat pipe 24 as desired.
[0025] FIG. 5 illustrates the heat pipe 24 in use. When the heat pipe 24 is subjected to temperatures above the predetermined temperature at a location 34 along the vessel 10 as indicated by arrows “A”, the working fluid 30 is caused to vaporize into a gas 36 . The gas 36 is then caused to flow to a cooler location in the heat pipe 24 as indicated by arrows “B”. Thus, heat is transferred through an interior of the heat pipe 24 and conducted by the casing 26 from the location subjected to temperatures above the predetermined temperature to the cooler location in heat pipe 24 . The gas 36 then condenses at the cooler location as indicated by arrows “C”. The condensing of the gas 36 emits heat, indicated by arrows “D”, at an end 38 of the heat pipe 24 thermally coupled to the PRD 22 . The vaporization and condensation cycle continues until the heat emitted actuates the PRD 22 . Upon actuation of the PRD 22 , the pressurized contents of the vessel 10 are vented.
[0026] However, if the heat pipe 24 is damaged, the working fluid 30 may leak from the heat pipe 24 . Accordingly, the heat pipe 24 becomes inoperable. When the heat pipe 24 is damaged, the fuse 32 disposed in the heat pipe 24 can actuate the PRD 22 . The fuse 32 may be activated by at least one of oxygen and a localized heat source. The heat generated is transferred by a progressive consumption of the fuse 32 through the interior of the heat pipe 24 to the end 38 of the heat pipe 24 thermally coupled to the PRD 22 . When the heat generated reaches a predetermined temperature, the PRD 22 is caused to actuate, thereby venting the pressured contents of the vessel 10 .
[0027] It is understood that the effectiveness of the heat pipe 24 is not limited to temperatures above the predetermined temperature being applied to the remote location 34 of the vessel 10 . The heat pipe 24 operates to transfer heat from any location along the vessel 10 to the cooler location along the heat pipe 24 . The PRD 22 and boss 20 are provided with substantial mass which will typically be the cooler location along the heat pipe 24 to which the heat will migrate.
[0028] From the foregoing description, one ordinarily skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, make various changes and modifications to the invention to adapt it to various usages and conditions.
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A heat pipe is disclosed, the heat pipe capable of transferring heat to actuate a pressure relief device by heat transfer through either capillary action involving a wicking material and a working fluid, or by a fuse in the case of leakage of the working fluid from the heat pipe.
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FIELD OF THE INVENTION
The present invention relates to the manufacture of chlorofluoroethanes of formula:
CF.sub.3 --CHF.sub.x Cl.sub.2-x (I)
where x is equal to 0 or 1, by catalytic hydrogenation of a perhaloethane of formula:
CF.sub.3 --CF.sub.x Cl.sub.3-x (II)
The two raw materials, included in the formula (II), are 1,1,1-trichloro-2,2,2-trifluoroethane (CF 3 CCl 3 ) and 1,1-dichloro-1,2,2,2-tetrafluoroethane (CF 3 CFCl 2 ), in which the substitution of a chlorine atom by a hydrogen atom produces 1,1-dichloro-2,2,2-trifluoroethane (CF 3 CHCl 2 ) and 1-chloro-1,2,2,2-tetrafluoroethane (CF 3 CHFCl) respectively.
BACKGROUND OF THE INVENTION
Catalytic hydrogenation of the compounds (II) has already been described, but the selectivities for the product corresponding to the removal of a single chlorine atom are low. Thus, hydrogenolysis of 1,1-dichloro-1,2,2,2-tetrafluoroethane at 280° C. over a catalyst containing 5% palladium on charcoal (Patent GB 1,578,933) yields a product containing 70% of 1,1,1,2-tetrafluoroethane. Similar results are obtained by C. Gervasutti et al. (Journal of Fluorine Chemistry 1981, 1, 1-20) over a catalyst containing 0.5% of palladium on charcoal: at 170° C. the hydrogenolysis of 1,1-dichloro-1,2,2,2-tetrafluoroethane produces 76% of 1,1,1,2-tetrafluoroethane.
Charcoal-supported metal catalysts containing 0.5% of rhenium, platinum or rhodium (Publications JP 132,536/89, 132,537/89 and 132,538/89 respectively) have also been tested in the hydrogenolysis of 1,1-dichloro-1,2,2,2-tetrafluoroethane; they result in the significant formation of 1,1,1-trifluoroethane, which can attain 30% at 200° C. Furthermore, the complete dechlorination of 1,1-dichloro-1,2,2,2-tetrafluoroethane on bimetallic catalysts based on palladium (Publication JP 172,348/89) or based on platinum (Publications JP 172,349/89 and 128,942/89) has also been described.
To solve the problem of the removal of a single chlorine atom it is necessary to resort, according to Japanese Patent Application 106,051/82 (Publication JP 222,038/83), to a chemical reduction with the zinc-ethanol couple; under the conditions described, the selectivity of the hydrogenolysis of 1,1,1-trichloro-2,2,2-trifluoroethane to 1,1-dichloro-2,2,2-trifluoroethane attains 90%. However, this process has the disadvantage of employing costly metallic zinc and of giving zinc chloride as a byproduct, which must be destroyed.
Advantageous results have been obtained in the catalytic hydrogenolysis with catalysts containing 0.5% of platinum on alumina or charcoal (Publication JP 149,739/89): at 175° C., with a catalyst on charcoal, 1,1,1-trichloro-2,2,2-trifluoroethane yields a product containing 64% of 1,1-dichloro-2,2,2-trifluoroethane, and at 200° C., with a catalyst on alumina, 1,1-dichloro-1,2,2,2-tetrafluoroethane yields a product containing 42% of 1-chloro-1,2,2,2-tetrafluoroethane.
DESCRIPTION OF THE INVENTION
It is has now been found that the catalytic removal of a single chlorine atom takes place highly selectively if an iridium-based catalyst is employed.
The subject of the present invention is therefore a process for the preparation of chlorofluoroethanes of formula (I) by catalytic hydrogenation of a perhaloethane of formula (II), characterized in that an iridium-based catalyst deposited on a support is employed.
In the catalyst employed according to the invention the iridium content can range from 0.1 to 10% by weight, but is preferably between 0.2 and 8%.
The support may be of very diverse nature and can be chosen, for example, from aluminas, aluminium fluoride and active charcoals. The preferred supports are charcoals which have a specific surface area of between 200 and 1500 m 2 /g (preferably between 600 and 1200 m 2 /g), a high porosity (0.3 to 0.7 cm 3 /g) and a particle size compatible with stationary-bed catalysis (1 to 10 mm). These products are marketed in extrudate or bead form by many companies.
The catalyst according to the invention may be prepared by impregnating the support with an aqueous or organic solution of an iridium derivative, evaporation of the water or of the solvent, and heat treatment at a temperature ranging from 150° to 500° C. (preferably 200° to 400° C.) and under a hydrogen stream (preferably at a pressure of 1 to 5 bars) to liberate the metal. The nature of the iridium derivative employed is of no importance and may be, for example, a chloride, chloroiridic acid or its ammonium salt.
The catalyst according to the invention may also be chosen from commercially available products, for example those of the Engelhard company, which offers catalysts containing from 0.5 to 5% of iridium on aluminas or charcoals.
The catalytic hydrogenation according to the invention may be performed at a temperature ranging from 50° to 300° C., preferably between 150° and 250° C. with a hydrogen/perhaloethane (II) molar ratio ranging from 0.5 to 8 (preferably 1 to 5), at a pressure of 1 to 20 bars (preferably 1 to 5 bars) and an hourly flow rate of 1 to 20 moles of perhaloethane (II) per liter of catalyst.
EXAMPLES
The following examples illustrate the invention without limiting it. In Examples 2 to 8, the results are expressed as the overall degree of conversion (DC o ) and the selectivity (S) for a product of the reaction: ##EQU1## the analysis at the reactor entry and exit being performed by in-line vapor phase chromatography.
EXAMPLE 1
Preparation of the catalysts
Catalyst A
60 ml (28 g) of an active charcoal which has a porosity of 0.6 cm 3 /g and a specific surface area of 950 m 2 /g in the form of extrudates 1.8 mm in diameter are charged into a rotary evaporator. After degassing for 3 hours at 100° C. at reduced pressure (1 kPa), 70 ml of an aqueous solution of iridium trichloride hydrate (53.3% Ir) containing 2.6 g of IrCl 3 are introduced and the water is then evaporated off under reduced pressure (1 kPa), followed by drying at 100° C. The product is then treated at 400° C. for 2 hours under a hydrogen stream (10 Nl/h) and a catalyst A containing 5% of iridium is thus obtained.
Catalyst B
By proceding in the same way, but with an aqueous solution containing 0.53 g of IrCl 3 , a catalyst B containing 1% of iridium is obtained.
Catalyst C
The procedure is the same as for preparing the catalyst B, except that the hydrogen treatment is performed at 200° C. instead of 400° C. The catalyst C thus obtained also contains 1% of iridium.
Catalyst D
The procedure is the same as for preparing the catalyst A, but the active charcoal is replaced with the same volume of an alumina which has a porosity of 0.48 cm 3 /g and a specific surface area of 129 m 2 /g in the form of 2-mm diameter spheres and an aqueous solution of iridium chloride containing 0.35 g of IrCl 3 is employed. A catalyst D containing 0.5% of iridium is thus obtained.
EXAMPLE 2
50 ml of the catalyst A described in Example 1 are introduced into an Inconel tube of 45 cm length and 2.72 cm internal diameter, which is heated electrically, and a mixture of hydrogen and of 1,1-dichloro-1,2,2,2-tetrafluoroethane is then passed through it in the molar ratios and at the flow rates and temperatures shown in the following table, the last part of which collates the results obtained.
TABLE 1______________________________________TEST No. 1 2 3 4______________________________________Operating conditions:Temperature (°C.) 100 130 150 200Molar ratio H.sub.2 /C.sub.2 F.sub.4 Cl.sub.2 5 5 5 5C.sub.2 F.sub.4 Cl.sub.2 flow rate (mole/hour) 0.05 0.05 0.05 0.05Results% DC.sub.0 of C.sub.2 F.sub.4 Cl.sub.2 4 42 97 100% S for CF.sub.3 CHFCl 86 84 74 50% S for CF.sub.3 CH.sub.2 F 9 9 13 20% S for CF.sub.3 CH.sub.3 4 6 13 30______________________________________
In most of the cases the selectivity for the hydrogenolysis of a single C--Cl bond is higher than 70%.
By way of comparison, two tests were performed with the catalyst A according to the invention replaced with a catalyst containing 5% of palladium, prepared in the same way and on the same support as in Example 1, with PdCl 2 instead of IrCl 3 . The results, collated in Table 2, which follows, show that with this palladium catalyst the selectivity of the reaction is clearly in favor of the abstraction of two chlorine atoms.
TABLE 2______________________________________COMPARATIVE TEST No. 5 6______________________________________Operating conditions:Temperature (°C.) 150 200Molar ratio H.sub.2 /C.sub.2 F.sub.4 Cl.sub.2 4 4C.sub.2 F.sub.4 Cl.sub.2 flow rate (mole/hour) 0.07 0.07Results% DC.sub.0 of C.sub.2 F.sub.4 Cl.sub.2 100 100% S for CF.sub.3 CHFCl 4 3% S for CF.sub.3 CH.sub.3 1 1.2% S for CF.sub.3 CH.sub.2 F 94.5 95______________________________________
EXAMPLE 3
In the same apparatus as in Example 2 and with a 25 ml charge of catalyst A, tests of hydrogenolysis of 1,1-dichloro-1,2,2,2-tetrafluoroethane are performed again while the molar ratio H 2 /CF 3 CFCl 2 is decreased.
The operating conditions of the tests and the results obtained are collated in Table 3, which follows.
TABLE 3______________________________________TEST No. 7 8 9______________________________________Operating conditions:Temperature (°C.) 103 153 200Molar ratio H.sub.2 /C.sub.2 F.sub.4 Cl.sub.2 1.5 1.5 1.5C.sub.2 F.sub.4 Cl.sub.2 flow rate (mole/hour) 0.07 0.07 0.07Results% DC.sub.0 of C.sub.2 F.sub.4 Cl.sub.2 26 62 97% S for CF.sub.3 CHFCl 88 79 76% S for CF.sub.3 CH.sub.3 6 12 17% S for CF.sub.3 CH.sub.2 F 6 7 7______________________________________
EXAMPLES 4-7
In the same apparatus as in Example 2 and with a 25 ml charge of catalyst, different tests of hydrogenolysis of 1,1-dichloro-1,2,2,2-tetrafluoroethane were performed, using catalysts B, C and D.
The operating conditions and the results of these tests are collated in Table 4, which follows.
TABLE 4______________________________________EXAMPLE. 4 5 6 7______________________________________Operating conditions:Catalyst B C C DTemperature (°C.) 150 150 190 230Molar ratio H.sub.2 /C.sub.2 F.sub.4 Cl.sub.2 4.5 5 5 1.5C.sub.2 F.sub.4 Cl.sub.2 flow rate (mole/hour) 0.03 0.05 0.05 0.07Results% DC.sub.0 of C.sub.2 F.sub.4 Cl.sub.2 55 59 83 97% S for CF.sub.3 CHFCl 81 90 92 76% S for CF.sub.3 CH.sub.3 11 6 4 14% S for CF.sub.3 CH.sub.2 F 8 4 4 6______________________________________
EXAMPLE 8
50 ml of a new charge of catalyst A is introduced into the same apparatus as in Example 2 and used to perform the hydrogenation of 1,1,1-trichloro-2,2,2-trifluoroethane (CF 3 --CCl 3 ).
The operating conditions of the test and the results obtained are collated in Table 5, which follows. Besides the expected product, 1,1-dichloro-2,2,2-trifluoroethane (CF 3 CHCl 2 ), the byproduct formed is chiefly 1,1,1-trifluoroethane (CF 3 CH 3 ) and 1-chloro-2,2,2-trifluoroethane (CF 3 CH 2 Cl).
TABLE 5______________________________________Operating conditions:Temperature (°C.) 160Molar ratio H.sub.2 /C.sub.2 F.sub.3 Cl.sub.3 1.5C.sub.2 F.sub.3 Cl.sub.3 flow rate (mole/hour) 0.06Results% DC.sub.0 of C.sub.2 F.sub.3 Cl.sub.3 68% S for CF.sub.3 CHFCl.sub.2 81% S for CF.sub.3 CH.sub.3 8% S for CF.sub.3 CH.sub.2 Cl 3______________________________________
Although the invention has been described in conjunction with specific embodiments, it is evident that many alternatives and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, the invention is intended to embrace all of the alternatives and variations that fall within the spirit and scope of the appended claims. The above references are hereby incorporated by reference.
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The invention relates to the manufacture of chlorofluoroethanes of formula CF 3 --CHF x Cl 2-x , where x is equal to 0 or 1, by catalytic hydrogenation of a perhaloethane of formula CF 3 --CF x Cl 3-x .
The use of an iridium-based catalyst deposited on a support enables the selectivity to be improved.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of manufacturing a metal/polymer composite article. More particularly, the present invention relates to a method of forming a metal/polymer composite article by spraying molten metal and polymeric materials to form articles composed of metal and polymer admixtures.
2. Description of the Related Art
There are several motivations to produce material article that incorporates both metallic and polymeric phases. The metal provides strength and durability while the polymeric material reduces the weight of the article and provides for lower frictional properties or allows for chemical interaction to occur through the article. While many possible applications exist for metal/polymeric composite materials, their manufacture has been difficult and expensive. Generally, the temperatures needed to melt metals of technological interest will vaporize most polymers.
Materials that have improved wear resistance, self lubricating, and or thermal insulating properties have been prepared by thermal spray processes. These materials have generally been applied atop a metal article as a thin coating. For example, U.S. Pat. No. 5,837,048, teaches a plasma spray coating of polymeric cellulose ether with a metal or ceramic powder. Between 1 and 10% by weight of the polymeric material is combined with the metal or ceramic and applied as a plasma spray feedstock. The polymeric, metal and ceramic materials are blended together combined and sprayed using a spray gun. The invention describes the complexities of spraying the mixture through a single spray gun. The spray temperatures for spraying metal and polymeric materials are different and the metal and polymeric materials tend to separate.
U.S. Pat. Nos. 5,434,210, 5,766,690 and 5,464,486 also teach methods of combining friction-reducing materials with metals and ceramics to produce powders that can be formed into abradable seals using thermal spray. Again, the metal and friction reducing material are premixed and applied using a single thermal spray gun. The mixture forms a relatively thin coating that is applied to a metal article. However, thermally spraying premixed metal/polymer or ceramic/polymer powders often produce unacceptable end results because the optimal conditions required (temperatures, type of projecting gas, voltage, current) metals, ceramics and polymers are significantly different. Consequently, the thermal spray parameters that optimize the microstructures and properties of one phase often produce undesirable chemistry and properties of the other.
Another use of a metal/polymeric article is as a separator for an electrical or chemical article. U.S. Pat. No. 5,021,259, teaches a method of applying a thermoplastic coating onto a porous metal surface by thermally spraying the thermoplastic polymer. The porous metal and coating are then heated to fuse the thermoplastic polymer coating into the porous metal. The metal supports the polymer and forms a protective covering for the metal. This patent additionally teaches a method of infiltrating a polymeric material into the surface of a metallic substrate. The polymer is applied as relatively thin coating atop a metal substrate. The metal substrate must first be formed to have the desired porosity network. The polymer coating must be melted to cause the coating to flow into the pores. Because of the relatively low viscosity of polymeric materials, the polymer only penetrates the area nearest to the surface of solid metals.
A relatively new material combines polymeric and metal materials into a single particle that can he used as a thermal spray powder feedstock. U.S. Pat. No. 5,660,934 teaches methods for manufacturing clad plastic powder particles suitable for thermal spray. These powder particles, consisting of a plastic core surrounded by ceramic or metal particles, can be thermal sprayed because the outer ceramic and metal particles protect the inner polymeric material for the high thermal spray temperature. These onerous ceramic or metal encapsulated polymeric particles are often used as a small fraction of an overall thermal spray feedstock material.
The salient feature of all of the above is that they teach various methodologies of improving the surface wear and corrosion properties of metallic articles using metal/polymer or ceramic/polymer composite coatings. In all cases the metallic substrate provides the bulk properties while the coating provides desired surface characteristics. These articles always require dual bulk and surface manufacturing steps and their useful life usually terminates once the surface coatings are removed. The cited references do not teach any methodology of making a complete article that incorporates intimate mixtures of metal and polymeric materials in its bulk. Additionally they do not teach the use of co-deposition techniques, using multiple and different thermal spray guns to form solid articles containing polymeric and metallic admixtures.
Traditional valve seats for sealing around poppet valves in internal combustion engines maybe made of sintered powdered metal compacts or alloy castings. Casting and sintering processes often require temperatures in excess of 1000° C. and limit the compositions available for use as valve seat inserts. Desirable solid lubricating materials such as MoS 2 and BN cannot be easily incorporated into the valve seat material because they either decompose, sublime, or fail to provide wetting at the melting or sintering temperatures of most metals. Traditional valve seats have not incorporated polymeric material because the processing temperatures needed to incorporate the polymeric material into the valve seats exceed the decomposition, boiling or degradation point of most polymeric materials.
The need for self lubricating valve seats is extremely important for compressed or liquid pressurized natural gas (CNG or LPG) fueled engines. Gasoline fuels contain additives that provide some degree of lubrication to the valves; especially the intake valves. Natural gas does not provide any lubrication to the valves. They run virtually dry. Consequently, traditional valve seats do not provide the required engine durability. Harder valve seat inserts particularly those containing significant amount of cobalt, molybdenum, chromium and lead have been used with natural gas engines but these components are much more costly than traditional valve seats inserts. Liquid sodium filled ultra light valves have also been used to reduce the heat buildup and the spring load between the valve and valve seat. These products are also expensive and can be problematic in case of unanticipated valve failure.
The present invention overcomes all of the above limitations and enables the manufacturing of a low cost metal/polymeric article that has polymeric material throughout the bulk thus providing the article with better friction and wear properties and extended life. The present invention also produces an article in a single step without the need for separate bulk and surface processing. The process incorporates simultaneous metal and polymer processing methodology to form metal/polymer composite article having required bulk and surface properties.
SUMMARY OF THE INVENTION
The present invention is directed to a method of manufacturing a metal and polymeric composite article by the following steps. A spray deposited metal alloy and a spray deposited polymeric material are combined to form an article having the polymeric material interspersed within the metal. A carrier or mandrel shaped to receive the metal and polymeric layers is provided. The carrier may be either stationary or movable. Spray deposited metal and spray deposited polymeric material are applied atop the carrier using coordinated multiple thermal spray guns. The metals and the polymers are deposited using different guns with optimized parameters for each material and deposition technique. The spray deposited article comprises between seventy five and ninety percent by volume of the article. The polymeric and metallic materials are intimately mixed within the bulk article. Adequate cooling is provided during deposition to prevent the degradation of the polymeric material and guarantee the appropriate bulk density.
A wide variety of metals, and polymeric materials are suitable for use with the present method including iron, nickel, copper and titanium based alloys as well as thermoplastic and thermoset epoxies such as polycarbonates, ketones and Teflon. The metal is usually supplied in the form of a wire or powder feed stock while the polymer is in powder or pellet form. The metal can be sprayed using conventional arc, plasma, or combustion processes while the polymer is deposited using flame or plasma techniques.
The method produces a composite article having the polymeric material phases encased or surrounded by the metallic ones. The polymeric material may be deposited substantially uniformly throughout the article or concentrated in areas of greatest need. The concentration and distribution of the metal and polymeric material can be controlled by the spraying process as will be more fully described below and in the attached drawings.
These and other desired objects of the present invention will become more apparent in the course of the following detailed description and appended claims. The invention may best be understood with reference to the accompanying drawings wherein illustrative embodiments are shown.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of one apparatus used for carrying out the thermal spray step of this invention making hollow ring-shaped articles.
FIG. 2 is a cross-sectional view of a hollow ring-shaped article made from the method of FIG. 1 .
FIGS. 3A-E are schematic illustrations of an alternative apparatus used for carrying out the thermal spray step of the invention making flat articles.
FIGS. 4A and 4B are a graphs comparing the performance of an automotive valve seat insert made using this invention with inserts made from cast and powder metallurgy.
FIG. 5 is a photomicrograph of the article made by the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention as illustrated in FIGS. 1-4 teaches a method of manufacturing automotive valve seat inserts (valve seats). The invention will also be described as a method of manufacturing a flat panel, however other components may also be manufactured using the same or similar process, technique and equipment, and are included within the invention described herein.
The following items are a word list of the items described in the drawings and are reproduced to aid in understanding the invention;
10 . Thermal spray apparatus
12 . Thermal spray gun
14 . Spray head
16 . Target mandrel surface
18 . Mandrel
20 . Direction of rotation
22 . Spray droplets from gun
24 . Feed supply
26 . Feed supply
28 . Thermal spray gun
30 . Polymeric material feed stock
32 . Spray droplets from gun
34 . Cylindrical metal and polymeric composite article
36 . Section
38 . Apparatus
40 , 42 . Metal spray guns
44 . Polymeric spray gun
46 . Spray
48 . Carrier
50 . Direction
52 . Polymeric spray
53 . Spray
54 . Edge
56 . Direction
Illustrated in FIG. 1 is a thermal spray setup 10 depositing layers of molten metal and molten plastic. The thermal spray gun 12 comprises a two-wire arc feedstock (however thermal spray gun 12 may be wire arc, powder plasma, or any other of the high velocity methods such as high velocity oxy-fuel (HVOF), detonation gun or cold gas-dynamic spraying).
The thermal spray gun 12 has a spray head 14 placed between 6-12 inches from the target mandrel surface 16 . A mandrel 18 rotates in the direction marked 20 . As the mandrel 18 rotates, the thermal spray gun 12 emits a spray 22 of molten droplets that deposit a layer of bulk material on the mandrel surface 16 . The deposition rate varies with the composition of the bulk material being deposited. However, deposition rates of between 2-10 pounds per hour provide adequate build time. The process for depositing bulk material on a rotating mandrel is illustrated in commonly assigned U.S. patent application Ser. No. 08/999,247, entitled “METHOD OF MAKING SPRAY FORMED INSERTS”, filed Dec. 29, 1997, now U.S. Pat. No. 5,983,495 and incorporated herein by reference. This patent application teaches a method of making valve seats by applying a bulk material to a rotating hollow mandrel.
The selection of the chemistry for the wire or feed supply 24 , 26 to the gun 12 , to carry out thermal spraying, is dependent upon the article to be formed by the thermal spray process. When manufacturing valve seats, feed supply 24 is selected from a nickel-based alloy having a composition of 58% nickel, 4% niobium, 10% molybdenum, 23% chromium, and 5% iron. The feed stock 26 is selected from a carbon steel having a composition of 1% carbon, 1.6-2% chromium, 1.6-1.9% manganese, and the balance iron. The two wire arc thermal spray gun 12 is operated at between 30-33 volts, 200-300 amps, using between 60-100 psi air as the propelling gas. The process forms molten metal spray droplets having a particle size of in the range of 10-100 μm in diameter.
The thermal spray gun 28 applies molten polymeric material simultaneously with the thermal spray gun 12 . Polymeric material is selected to provide continuous lubrication of the valve seat during engine operation. The glass transition temperature T g , degree of crystallinity, impact fatigue strength, alkane solubility, re-crystallization temperature, high melting point, and high shear viscosity are all important properties a polymeric material must possess in order to be used in high temperature applications such as in valve seats inserts.
A thermoplastic polyethylene ethyl ketone (PEEK) was selected as the polymeric material feedstock 30 . PEEK was selected because of its high temperature chemical stability, high melting point, and complete insolubility in alkane. The material used has an average particle size of 40-60 Mm, 30-40% crystallinity, a T g of 289° F., a melting temperature of 649° F., a heat distortion temperature of 599° F., and a continuous use temperature of 500° F. Other polymeric materials such as fluoropolymers, thermoplastic polycarbonates and elastomers, and polyimides can be used.
The PEEK feed stock 30 is sprayed in a propane flame using air or argon as the propelling gas. The gun 28 produces a polymeric spray droplets 32 . The guns 12 and 28 are positioned at 15-30 cm and 5-15 cm respectively from the mandrel surface 16 during deposition. The gun 12 was turned on first and allowed to deposit about 1 mm thick material before gun 28 is turned on. Due to the rotation of mandrel 18 , the sprayed layer is an intimate mixture of solidified polymeric and metallic droplets. Various metal to polymer proportions can be produced by adjusting the parameters of spray guns 12 and 28 respectively. The percentage by volume of metal is between 75 and 90%. More preferably, the percentage of metal is between 90 and 95%. The metal percentage by weight is between 90 and 98%, more preferably between 93 and 95%.
A build-up of intermixed metal and polymer sprays from droplets 22 and 32 forms until the metal/polymeric composite article 34 is formed. The article 34 is r-moved from the mandrel 20 , machined to specified dimensions and cut into thin sections 36 as illustrated in FIG. 2 . Alternatively, the mandrel 20 is machined away prior to sectioning. In another practice of the invention, the flame was turned off in gun 30 during the polymer spray onto the surface 16 simultaneously with the metal deposition. The heat from the molten metal spray heated the polymer spray sufficiently to soften the polymer and form the metal/polymer admixture.
Illustrated in FIGS. 3 a- 3 d is the method of making flat panels having layers or admixtures of independently sprayed metal and polymeric material. The thermal spray apparatus 38 includes a bank of metal spray guns 40 , 42 and polymeric spray gun 44 . The guns can be independently controlled to deposit alternating or mixed layers on carrier 48 . The metal spray gun 40 applies a molten metal spray 46 onto a carrier 48 . The carrier 48 serves as a target to receive the molten metal and polymeric spray. The bank of spray guns 40 , 42 , 44 are moved in the direction 50 and the spray gun 44 applies a polymeric spray 52 on top of the previously applied metal spray layer as shown in FIG. 3 b . The spray guns 40 , 42 , 44 are moved further in the direction 50 as illustrated in FIG. 3 c . The spray gun 42 applies a molten metal spray 53 atop the previously applied polymeric layer. The molten metal spray 53 may be the same or different from the metal spray 46 . The spray guns 40 , 42 , 44 are moved in direction 50 as shown in FIG. 3 d . The spray gun 40 ceases applying the thermal spray when it reaches the edge 54 of the carrier 48 . Likewise, the spray gun 44 , 42 also cease spraying when they reach the edge 54 . The spray guns 40 , 42 , 44 are then cycled back in the direction 56 and the spray gun 44 applies polymeric spray 52 and then the spray gun 40 applies a metal spray 46 as illustrated in FIG. 3 e.
In this way, metal and polymeric layers may be continuously applied to the carrier 48 without having a build-up of either metal or polymeric material along the edge 54 or over-spraying beyond the perimeter of the carrier 48 .
The invention was found to be especially well suited for the manufacture of internal combustion engine valve seats. The valve seats were manufactured using the forgoing process. An elongated tube was formed around the mandrel and then cut into thin sections which were subsequently machined into valve seats. The valve seats included the PEEK polymer throughout the seat. This construction enabled the manufacture of valve seats that could be used with conventional valves in CNG engines. The inclusion of the PEEK polymer permitted a permanent lubrication of the valve/valve seat interface during engine operation. Illustrated in FIG. 4B is the performance evaluation of valve seat inserts made using this invention, cast inserts as well as powder metallurgy ones. The dynamometer testing was done on production 2.0 liter modular, in-line 4 cylinder, 4 valve engine under full load, wide open throttle at 5800 rpm. Given that only 75 mm was the maximum allowable recession on this engine, only the valve seat inserts manufactured using this invention meets adequate performance criteria, particularly in intake applications.
The comparative performance of valve seats made from the metal/PEEK material and those made from conventional Powder Metal and Cast Alloys. Valve seats made from metal/PEEK substantially better wear resistance (measured as recessions) than either the Powder Metal Alloy or Cast Alloy valve seats. The improved performance is believed to be the result of incorporating the PEEK throughout the body of the valve seat and not merely as a coating.
Illustrated in FIG. 5 is a photomicrograph of the metal and polymeric composite material made according to the present invention. The polymeric material appears as the dark spots. The polymeric material is distributed evenly throughout the material.
The invention has been described as a method of manufacturing an engine valve seat and a flat sheet. While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention as defined by the following claims.
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A method of manufacturing a metal and polymeric composite article by the following steps. Droplets of spray deposited metal and spray deposited polymeric material are combined to form an article having the polymeric material interspersed within the metal. A carrier or form that shaped to receive the metal and polymeric layers is provided. The carrier may be made either stationary or movable. Layers of spray deposited metal and spray deposited polymeric material are applied atop the carrier. The spray deposited metal is between 90 and 95 percent by volume of the article. The polymeric layers do not completely cover the metal layers. Succeeding spray deposited metal layers contact bond to previous metal layers. The polymeric material between imbedded between the interconnected metal layers.
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FIELD OF THE INVENTION
The present invention relates to a double winding type electrode assembly, and, more particularly, to a double winding type electrode assembly constructed in a structure in which a cathode and an anode are opposite to each other while a separator is disposed between the cathode and the anode, wherein the electrode assembly is manufactured by preparing a plurality of cell units, each cell unit having a cathode sheet and an anode sheet, of a predetermined size, wound, while a separator is disposed between the cathode sheet and the anode sheet, each cell unit being elliptical in section, and sequentially winding the cell units while arranging the cell units on a long separator sheet.
BACKGROUND OF THE INVENTION
As mobile devices have been increasingly developed, and the demand for such mobile devices has increased, the demand for batteries has also sharply increased as an energy source for the mobile devices. Accordingly, much research on batteries satisfying various needs has been carried out.
In terms of the shape of batteries, the demand for prismatic secondary batteries or pouch-shaped secondary batteries, which are thin enough to be applied to products, such as mobile phones, is very high. In terms of the material for batteries, the demand for lithium secondary batteries, such as lithium ion batteries and lithium ion polymer batteries, having high energy density, high discharge voltage, and high output stability, is very high.
Furthermore, secondary batteries may be classified based on the construction of an electrode assembly having a cathode/separator/anode structure. For example, the electrode assembly may be constructed in a jelly-roll (winding) type structure in which long-sheet type cathodes and anodes are wound while separators are disposed respectively between the cathodes and the anodes, a stacking type structure in which pluralities of cathodes and anodes having a predetermined size are successively stacked one on another while separators are disposed respectively between the cathodes and the anodes, or a stacking/folding type structure in which pluralities of cathodes and anodes having a predetermined size are successively stacked one on another, while separators are disposed respectively between the cathodes and the anodes, to constitute a bi-cell or a full-cell, and then the bi-cell or the full-cell is wound. The details of the stacking/folding type electrode assembly are disclosed in Korean Patent Application Publication No. 2001-0082058, No. 2001-0082059, and No. 2001-0082060, which have been filed in the name of the applicant of the present patent application.
However, the conventional electrode assemblies have several problems.
First, the jelly-roll type electrode assembly is manufactured by densely winding long-sheet type cathodes and anodes with the result that the jelly-roll type electrode assembly is circular or elliptical in section. Consequently, stress, generated by the expansion and contraction of the electrodes during the charge and discharge of the electrode assembly, accumulates in the electrode assembly, and, when the stress accumulation exceeds a specific limit, the electrode assembly may be deformed. The deformation of the electrode assembly results in the nonuniform gap between the electrodes. As a result, the performance of the battery is abruptly deteriorated, and the safety of the battery is not secured due to an internal short circuit of the battery. Furthermore, it is difficult to rapidly wind the long-sheet type cathodes and anodes while maintaining uniformly the gap between the cathodes and anodes, and therefore, the productivity is lowered.
Secondly, the stacking type electrode assembly is manufactured by sequentially stacking pluralities of unit cathodes and anodes. As a result, it is additionally necessary to provide a process for transferring electrode plates, which are used to manufacture the unit cathodes and anodes. Furthermore, a great deal of time and effort is required to perform the sequential stacking process, and therefore, the productivity is lowered.
Thirdly, the stacking/folding type electrode assembly considerably makes up for the defects of the jelly-roll type electrode assembly and the stacking type electrode assembly. However, a stacking process is necessary to manufacture the bi-cell or the full-cell. Consequently, the stacking/folding type electrode assembly is not a complete solution.
In conclusion, the jelly-roll type electrode assembly is preferred in the aspect of productivity, and the stacking type electrode assembly and the stacking/folding type electrode assembly are preferred in the aspect of operational performance and safety of the battery. Nevertheless, there is high necessity for a new electrode assembly that is capable of providing higher productivity and operational performance of a battery while making up for the defects of the conventional electrode assemblies.
Especially, a large-sized battery module, which is used for middle- or large-sized devices, such as electric vehicles or hybrid electric vehicles, which have lately attracted much attention, needs a large number of battery cells (unit cells). Furthermore, it is required that the large-sized battery module have a long service life characteristic. Consequently, a new electrode assembly that can solve all the above-mentioned problems is seriously needed.
SUMMARY OF THE INVENTION
Therefore, the present invention has been made to solve the above problems, and other technical problems that have yet to be resolved.
As a result of a variety of extensive and intensive studies and experiments to solve the problems as described above, the inventors of the present invention have developed an electrode assembly constructed in a structure in which winding type cell units, as unit bodies, are wound while the cell units are arranged on a long separator sheet, and found that the double winding type electrode assembly is manufactured with a high productivity equivalent to that of the conventional jelly-roll type electrode assembly, and, in addition, the double winding type electrode assembly exhibits a high operational efficiency and safety equivalent to the conventional stacking type or stacking/folding type electrode assembly even after the electrode assembly according to the present invention is used for a long period of time. The present invention has been completed based on these findings.
In accordance with one aspect of the present invention, the above and other objects can be accomplished by the provision of a double winding type electrode assembly constructed in a structure in which a cathode and an anode are opposite to each other while a separator is disposed between the cathode and the anode, wherein the electrode assembly is manufactured by preparing a plurality of cell units, each cell unit having a cathode sheet and an anode sheet, of a predetermined size, wound, while a separator is disposed between the cathode sheet and the anode sheet, each cell unit being elliptical in section, and sequentially winding the cell units while arranging the cell units on a long separator sheet.
The electrode assembly according to the present invention is basically based on the winding structure, and therefore, it is possible to manufacture the electrode assembly according to the present invention with a higher productivity than the stacking structure. On the other hand, each cell unit is constructed in a structure in which the cathode and the anode are wound by the reduced number of winding times, with the result that stress, generated by the expansion and contraction of the electrodes during the continuous charge and discharge of the electrode assembly, does not accumulate in the electrode assembly, and therefore, the electrode assembly according to the present invention is not deformed even after the electrode assembly is used for a long period of time. For the jelly-roll type electrode assembly, the number of winding times of the electrode sheets is very large, and therefore, a large frictional force is generated in the longitudinal direction of the electrode sheets during the winding process. Furthermore, the stress, generated in the longitudinal direction of the electrode sheets by the expansion and contraction of the electrodes, is not removed due to the frictional force but accumulates in the electrode assembly. However, each cell unit of the present invention is constructed in a structure in which the electrode sheets are wound by the reduced number of winding times. Consequently, only a small frictional force is generated in the longitudinal direction of the electrode sheets during the winding process, and therefore, the stress accumulation does not occur.
The cell units are small-sized winding type unit cells, which are elliptical in section. The cell units may be manufactured by winding the cell units in a circular shape in section and then compressing the wound cell units such that the cell units are formed in the elliptical shape, or winding the cell units in an elliptical shape from the beginning. Preferably, the separator, disposed between the cathode and the anode, extends longer than the outer winding end of each electrode, such that the occurrence of a short circuit due to the contact between the cathode and the anode is prevented during the winding process or the operation of the electrode assembly. The elliptical sectional structure is substantially similar to a thin stacked sheet structure.
The number of winding times of each cell unit is, preferably 1 to 5, more preferably 2 to 4, based on the number of bending times of the respective electrode sheets in the elliptical structure. When the number of winding times of each cell unit is too large, the stress accumulation may occur, during the charge and discharge of the electrode assembly, due to the increase of the frictional force in the longitudinal direction of the electrode sheets.
When the winding process is performed to manufacture of each cell unit, the inside winding end of the cathode and the inside winding end of the anode may be located at approximately the same winding start point, or the inside winding end of the cathode and the inside winding end of the anode may be opposite to each other at the winding start point. Here, the term “inside winding end” means the end, of each electrode sheet, located at the inside of the each cell unit when each electrode sheet is wound in the circular or elliptical shape. Whereas, the term “outside winding end” means the end, of each electrode sheet, located at the outside of the each cell unit when each electrode sheet is wound.
The cell units may be constructed in various structures depending upon the location of the outside winding ends of the electrode sheets constituting each cell unit. For example, each cell unit may be a cell unit constructed in a structure in which the upper end electrode and the lower end electrode have different polarities (hereinafter, referred to as an ‘A-type cell unit’) or a cell unit constructed in a structure in which the upper end electrode and the lower end electrode have the same polarity (hereinafter, referred to as an ‘B-type cell unit’).
The A-type cell unit may be constructed in a structure in which the outside winding end of the cathode and the outside winding end of the anode are located on the same plane or a structure in which the outside winding end of the cathode and the outside winding end of the anode are not located on the same plane. Preferably, opposite round sides of each cell unit are surrounded by the anode sheet. This is because the anodes occupy a relatively large area, when a plurality of cell units are stacked in a cathode/anode facing structure, and therefore, when the electrode assembly according to the present invention is used, for example, in a lithium secondary battery, the dendritic growth of lithium metal at the anode is maximally retrained during the charge and discharge of the lithium secondary battery.
The B-type cell unit may be constructed in a structure in which the anode forms the outer winding surface or a structure in which the cathode forms the outer winding surface. Preferably, however, the outside winding end of the anode extends longer than the outside winding end of the cathode such that the dendritic growth of lithium metal is retrained.
As described above, the cell units are located on the long separator sheet, and are then wound, such that the cathodes and the anodes face each other at the interfaces of the cell units, to manufacture a double winding type electrode assembly according to the present invention.
In a preferred embodiment, the first cell unit, with which the winding process is initiated, and the second cell unit, among the cell units arranged on the separator sheet, are spaced apart from each other by a length sufficient such that the lower end electrode of the first cell unit is brought into contact with the upper end electrode of the second cell unit after the outer surface of the first cell unit is completely covered by the separator sheet during the winding process. Specifically, the first cell unit and the second cell unit are located on the separator sheet while the first cell unit and the second cell unit are spaced apart, by a distance corresponding to the width of at least one cell unit, from each other, and then the process for winding the cell units is performed.
As a result, the cell units are wound in a structure in which the upper end electrode of the first cell unit and the upper end electrode of the third cell unit have opposite polarities, the lower end electrode of the second cell unit and the upper end electrode of the fourth cell unit have opposite polarities, and the lower end electrode of the third cell unit and the upper end electrode of the fifth cell unit have opposite polarities. Based on this winding structure, it is possible to arrange the cell units in various structures as described above.
Preferably, the electrode assembly is constructed in a structure in which the lower end electrode of the last cell unit on the separator sheet (n th cell unit) and the lower end electrode of the n−1 th cell unit adjacent to the n th cell unit are anodes. The lower end electrode of the last cell unit and the lower end electrode of the n−1 th cell unit form the outer surface of the electrode assembly, i.e., the upper and lower end surfaces of the electrode assembly. Consequently, it is possible to maximally restrain the dendritic growth as previously described.
In this connection, several exemplary arrangements of the cell units are possible as follows.
In a first exemplary arrangement, the first cell unit and the second cell unit are A-type cell units whose upper end electrodes are cathodes (hereinafter, referred to as ‘Ac-type cell units’), the third cell unit is an A-type cell unit whose upper end electrode is an anode (hereinafter, referred to as an ‘Aa-type cell unit’), the fourth cell unit and the following cell units are sequentially disposed in a structure in which the Ac-type cell units and the Aa-type cell units are alternately arranged, and the n th cell unit is a B-type cell unit whose outer surface is an anode (hereinafter, referred to as a ‘Ba-type cell unit’).
In a second exemplary arrangement, the first cell unit and the second cell unit are Aa-type cell units, the third cell unit is an Ac-type cell unit, the fourth cell unit and the following cell units are sequentially disposed in a structure in which the Aa-type cell units and the Ac-type cell units are alternately arranged, the n−1 th cell unit is a Ba-type cell unit, and the n th cell unit is an Ac-type cell unit.
In a third exemplary arrangement, the first cell unit is a Ba-type cell unit, the second cell unit and the third cell unit are B-type cell units whose outer surfaces are cathodes (hereinafter, referred to as ‘Bc-type cell units’), the fourth cell unit and the following cell units are sequentially disposed in a structure in which the Bc-type cell units and the Ba-type cell units are alternately arranged two by two, and the n−1 th cell unit and the n th cell unit are Ba-type cell units.
However, other arrangements are also possible, and they must be interpreted to be within the scope of the present invention.
The number of cell units, wound while being located on the separator sheet, may be decided depending upon various factors, such as the number of winding times of each cell unit and the desired capacity of each cell unit. Preferably, the number of cell units is 2 to 10.
The separator sheet is not particularly restricted so long as the separator sheet is insulative and is constructed in a porous structure to allow the movement of ions like the separator disposed between the cathode and the anode of each cell unit.
In a preferred embodiment, the cell units are bonded to the separator sheet before the commencement of the winding process, such that the process for winding the cell units is easily performed on the separator sheet. At this time, the bonding of the cell units to the separator sheet may be accomplished, for example, by applying a solution, having a polymer, such as PVDF, HFD, PMMA, PEO, or PMMA, which is easily laminated at a low glass temperature (TG) and electrochemically stable at a potential range of 0 to 5 V, dissolved in a predetermined solvent, to a separator and drying the solution applied to the separator, to manufacture a separator sheet coated with a binder, placing cell units on the separator sheet, and applying predetermined pressure and heat to the cell units and the separator sheet.
The binder-coated separator sheet may be used as the separator material of each cell unit. The binder-coated separator sheet serves to maintain the elliptical sectional shape of each cell unit, during the manufacture of the electrode assembly, due to the coupling force between the binder-coated separator sheet and the electrodes.
The electrode assembly manufactured as described above may be applied to an electrochemical cell to generate electricity through the electrochemical reaction between the cathode and the anode. Typically, the electrode assembly is applied to a secondary battery.
The secondary battery is constructed in a structure in which an electrode assembly, which can be charged and discharged, is mounted in a battery case, while the electrode assembly is impregnated with an ion-containing electrolyte. In a preferred embodiment, the secondary battery is a lithium secondary battery.
Recently, the lithium secondary battery has attracted much attention as a power source of large-sized devices as well as small-size mobile devices. When the lithium secondary battery is applied to such devices, it is preferable for the lithium secondary battery to be light in weight. Preferably, a solution for reducing the weight of the secondary battery is to mount the electrode assembly in a pouch-shaped case made of an aluminum laminate sheet.
Furthermore, when the secondary battery is used as a power source for middle- or large-sized devices, as described above, it is preferable that the deterioration of the operational performance of the secondary battery be maximally restrained even after the secondary battery is used for a long period of time, the service life characteristics of the secondary battery be excellent, and the secondary battery be mass-produced with low costs. In this connection, the secondary battery including the electrode assembly according to the present invention is preferably used in a middle- or large-sized battery module as a unit cell.
The middle- or large-sized battery module is manufactured by connecting a plurality of unit cells in series or in series/parallel with each other such that the middle- or large-sized battery module provides high output and large capacity. The structure of the middle- or large-sized battery module is well known in the art to which present invention pertains, and therefore, a related description thereof will not be given.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
FIGS. 1 to 4 are vertical sectional views illustrating exemplary A-type cell units that can be used in an electrode assembly according to an embodiment of the present invention;
FIGS. 5 to 8 are vertical sectional views illustrating exemplary B-type cell units that can be used in an electrode assembly according to an embodiment of the present invention;
FIGS. 9 to 12 are typical views illustrating various arrangements of cell units when manufacturing an electrode assembly according to the present invention;
FIGS. 13 and 14 are typical views illustrating the electrode facing relationships during the stacking process of the cell units through the winding operation of the cell units based on the arrangement of FIG. 10 and the arrangement of FIG. 12 , respectively; and
FIG. 15 is a vertical sectional view typically illustrating an electrode assembly according to an embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Now, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted, however, that the scope of the present invention is not limited by the illustrated embodiments.
FIGS. 1 to 3 are vertical sectional views typically illustrating exemplary A-type cell units that can be used in an electrode assembly according to an embodiment of the present invention, and FIGS. 5 to 7 are vertical sectional views typically illustrating exemplary B-type cell units that can be used in an electrode assembly according to an embodiment of the present invention. For convenience of description, separators, which are disposed respectively between cathodes and anodes, are omitted from the accompanying drawings. In addition, although the cell units, which are elliptical in section, are constructed in a substantially thin stacked sheet structure, as previously described, the cell units are exaggeratingly shown in the accompanying drawings for easy understanding.
Referring to these drawings, cell units 100 , 100 a , 200 , 300 , 300 a , and 400 are constructed in a flat elliptical structure in section. The cell units 100 , 100 a , 200 , 300 , 300 a , and 400 have electrode sheets, which are wound three or four times based on the number of bending times of the respective electrode sheets. Consequently, a large frictional force is not generated in the longitudinal direction of the electrode sheets, as compared to the conventional jelly-roll type electrode assembly, and therefore, stress accumulation does not occur during the charge and discharge of the electrode assembly.
Referring to FIG. 1 , the cell unit 100 is constructed in a structure in which the inside winding end 122 of an anode 110 is opposite to the inside winding end of a cathode 120 at the winding start point.
As in the cell unit 100 a of FIG. 3 , on the other hand, the inside winding end 112 of the anode 110 and the inside winding end 122 of the cathode 120 may be located at approximately the same winding start point. At this time, the inside winding end 112 of the anode 110 extends longer than the inside winding end 122 of the cathode 120 so as to further restrain the dendritic growth of lithium metal, as previously described. Also, no active material is applied to the extension region.
Although the winding start points are located at the same position, however, as in the cell unit 100 b of FIG. 4 , the inside winding end 112 of the anode 110 may extend longer than the inside winding end 122 of the cathode 120 , while the anode 110 is partially overlapped at the winding start region.
The winding structure of the cell unit may be confirmed through the cell unit 300 a of FIG. 7 and the cell unit 300 b of FIG. 8 , both of which are modifications of the cell unit 300 of FIG. 5 . Specifically, the inside winding end 312 of an anode 310 and the inside winding end 322 of a cathode 320 are located at approximately the same winding start point, while the inside winding end 312 of the anode 310 extends longer than the inside winding end 322 of the cathode 320 . However, the cathode 320 may be partially overlapped at the winding start region, as shown in FIG. 7 , or the anode 310 may be partially overlapped at the winding start region, as shown in FIG. 8 .
On the other hand, the cell units 100 , 200 , 300 , and 400 may be constructed in various structures based on the location of the outside winding ends of the electrode sheets constituting the cell units 100 , 200 , 300 , and 400 .
First, the A-type cell unit 100 of FIG. 1 and the A-type cell unit 200 of FIG. 2 are constructed in a structure in which the upper end electrode and the lower end electrode have different polarities. Specifically, the A-type cell unit 100 is constructed in a structure in which the outside winding ends 114 and 124 of the anode 110 and the cathode 120 are located on the same plane, whereas the A-type cell unit 200 is constructed in a structure in which the outside winding ends 214 and 224 of the anode 210 and the cathode 220 are not located on the same plane. Opposite round sides a of the A-type cell unit 100 are surrounded by the anode sheet 110 , and therefore, it is possible to further restrain the dendritic growth of lithium metal.
On the other hand, the B-type cell unit 300 of FIG. 5 and the B-type cell unit 400 of FIG. 6 are constructed in a structure in which the upper end electrode and the lower end electrode have the same polarity. Specifically, the Ba-type cell unit 300 is constructed in a structure in which the anode 310 forms the outer winding surface, whereas the Bb-type cell unit 400 is constructed in a structure in which the cathode 420 forms the outer winding surface. In the B-type cell units 300 and 400 , the outside winding ends 314 and 414 of the anodes 310 and 410 extend longer than the outside winding ends 324 and 424 of the cathodes 320 and 420 .
Separators (not shown) of the cell units 100 , 200 , 300 , and 400 extend at least longer than the outside winding ends 314 and 414 of the anodes 310 and 410 so as to prevent the occurrence of a short circuit due to the contact between the cathodes and the anodes. Also, the separators, the cathodes, and the anodes are preferably bonded to each other using a specific binder so as to maintain the wound state of the respective cell units 100 , 200 , 300 , and 400 .
FIGS. 9 to 12 are typical views illustrating various arrangements of cell units when manufacturing an electrode assembly according to the present invention.
Referring first to FIG. 9 , cell units are arranged on a long separator sheet, and then the cell units are sequentially wound from the right-side cell unit, so as to manufacture an electrode assembly.
The first cell unit 501 and the second cell unit 502 are located on the separator sheet while the first cell unit 501 and the second cell unit 502 are spaced apart by at least a distance corresponding to the width of one cell unit from each other. Consequently, when the outer surface of the first cell unit 510 is completely covered by the separator sheet 910 according to the winding operation, the lower end electrode of the first cell unit 501 is brought into contact with the upper end electrode of the second cell unit 502 .
During the sequential stacking process through the winding operation, the application length of the separator sheet 910 increases. For this reason, the cell units 502 , 503 , 504 , and 505 are arranged such that the distance between the respective cell units 502 , 503 , 504 , and 505 is gradually increased in the winding direction.
Also, during the stacking process, the respective cell units are constructed such that the cathodes and the anodes face each other at the stacked interfaces. Specifically, the first cell unit 501 and the second cell unit 502 are Ac-type cell units whose upper end electrodes are cathodes, the third cell unit 503 is an Aa-type cell unit whose upper end electrode is an anode, the fourth cell unit 504 is an Ac-type cell unit, and the final fifth cell unit 505 is a B-type anode cell unit whose outer surface is an anode.
Referring to FIG. 10 illustrating another example, the first cell unit 601 and the second cell unit 602 are Aa-type cell units, the third cell unit 603 is an Ac-type cell unit, the fourth cell unit 604 is a B-type anode cell unit, and the final fifth cell unit 605 is an Ac-type cell unit.
Referring to FIG. 11 illustrating a further example, the first cell unit 701 is a Ba-type cell unit, the second cell unit 702 and the third cell unit 703 are Bc-type cell units, the fourth cell unit 704 is a Ba-type cell unit, and the final fifth cell unit 705 is a Ba-type cell unit.
The arrangement of FIG. 12 is the same as the arrangement of FIG. 11 ; however, the respective cell units 801 , 802 , 803 , 804 , and 805 are wound by a reduced number of winding times, specifically, the number of winding times which is one time less than that of FIG. 11 .
For clearer understanding about the above-described arrangement modes, the electrode facing relationships during the stacking process of the cell units through the winding operation of the cell units based on the arrangement of FIG. 10 and the arrangement of FIG. 12 are illustrated respectively in FIGS. 13 and 14 .
Referring first to FIG. 13 , the first cell unit 601 and the second cell unit 602 are wound while the first cell unit 601 and the second cell unit 602 are spaced apart by a distance corresponding to the width of one cell unit. As a result, the upper end electrode (anode) of the first cell unit 601 is brought into contact with the upper end electrode (cathode) of the third cell unit 603 . Also, the lower end electrode (cathode) of the first cell unit 601 is brought into contact with the upper end electrode (anode) of the second cell unit 602 . Consequently, when the first cell unit 601 is an Aa-type cell unit, the second cell unit 602 must be an Aa-type cell unit or a Ba-type cell unit, and the third cell unit 603 must be an Ac-type cell unit or a Bc-type cell unit.
On the other hand, the second cell unit and the following cell units 602 , 603 . . . are sequentially stacked without a distance corresponding to the width of one cell unit. As a result, the lower end electrode (cathode) of the second cell unit 602 is brought into contact with the upper end electrode (anode) of the fourth cell unit, and the lower end electrode (anode) of the third cell unit 603 is brought into contact with the upper end electrode (cathode) of the fifth cell unit. Consequently, it is necessary for the cell units to be alternately arranged two by two, and therefore, the second cell unit 602 must be an Aa-type cell unit, and the third cell unit 603 must be an Ac-type cell unit.
Meanwhile, the lower end electrode of the n th cell unit 600 n and the lower end electrode of the n−1 th cell unit 600 n −1 form the outer surface of the electrode assembly at the final position. Preferably, therefore, the lower end electrode of the n th cell unit 600 n and the lower end electrode of the n−1 th cell unit 600 n −1 are anodes.
Referring now to FIG. 14 , the upper end electrode (anode) of the first cell unit 801 is brought into contact with the upper end electrode (cathode) of the third cell unit 803 , and the lower end electrode (anode) of the first cell unit 801 is brought into contact with the upper end electrode (cathode) of the second cell unit 802 . Consequently, when the first cell unit 801 is a Ba-type cell unit, the second cell unit 802 and the third cell unit 803 must be an Ac-type cell unit or a Bc-type cell unit.
Also, in the same principle as the previous description, the lower end electrode of the second cell unit 802 is brought into contact with the upper end electrode of the fourth cell unit, and the lower end electrode of the third cell unit 903 is brought into contact with the upper end electrode of the fifth cell unit. Consequently, the electrodes at the interfaces therebetween must have different polarities, and therefore, the second cell unit 802 and the third cell unit 803 must be a Bc-type cell unit.
An exemplary electrode assembly manufactured by the process described above is typically illustrated in FIG. 15 .
Referring to FIG. 15 , various kinds of unit cells 901 , 902 , 903 . . . are sequentially wound, while the unit cells 901 , 902 , 903 . . . are arranged on a separator sheet 901 in a specific combination, to constitute an electrode assembly 900 . The separator sheet 901 has a length sufficient to cover the electrode assembly 900 once after the completion of the winding process.
Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
INDUSTRIAL APPLICABILITY
As apparent from the above description, the electrode assembly according to the present invention is manufactured with a high productivity equivalent to that of the conventional jelly-roll type electrode assembly. Furthermore, the electrode assembly according to the present invention exhibits a high operational efficiency and safety equivalent to the conventional stacking type or stacking/folding type electrode assembly even after the electrode assembly according to the present invention is used for a long period of time.
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Disclosed herein is a double winding type electrode assembly constructed in a structure in which a cathode and an anode are opposite to each other while a separator is disposed between the cathode and the anode, wherein the electrode assembly is manufactured by preparing a plurality of cell units, each cell unit having a cathode sheet and an anode sheet, of a predetermined size, wound, while a separator is disposed between the cathode sheet and the anode sheet, each cell unit being elliptical in section, and sequentially winding the cell units while arranging the cell units on a long separator sheet.
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BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to shipping and storage containers and more particularly to containers in which the base serves as a reusable pallet and which further has an independent top and bottom thereof.
Containers are used in a wide variety of applications requiring the storage and transportation of industrial goods. Many previous container designs employed wooden pallets which served as supporting members for these goods. The use of these pallets had several drawbacks, however, as the pallets required much valuable warehouse space, were subject to relatively easy breakage, and were not reusable over a relatively long period of time.
Improvements in container designs have been made and one such improvement is shown in U.S. Pat. No. 4,550,830. This patent discloses a reusable pallet and a sleeve in the form of a cardboard box open at its lower end. A plurality of foldable tabs are integrally formed along the bottom edge of the sleeve. These tabs co-operate with the pallet so as to pass therethrough and be folded underneath the pallet so as to hold the sleeve, the pallet, and a top in assembly relation thereby forming a container. Other composite containers are shown in U.S. Pat. Nos. 4,648,521 and 4,793,519 owned by the assignee of this application.
The pallet is preferably formed with a peripheral groove lying substantially at floor level to receive the edge of the sleeve in order that compressive forces applied to the container be transferred by the container to the floor. While improving over the wooden pallet design, the use of the tabs for connecting the pallet and sleeve can be improved on.
According to the present invention, a container is provided which employs a reusable pallet having a sidewall member having a plurality of openings therein, adjacent the bottom periphery thereof. The sidewall member and the pallet co-operate to define a recessed groove portion around the periphery of the pallet which at its upper end is raised above the surface upon which the pallet is placed. A sleeve in the form of an open bottom cardboard box is disposed within the defined groove portion, the sleeve having openings therein in communication with the openings of the sidewall portion.
A removable retainer clip is removeably extended through each of said openings and through the associated communicating sleeve opening while encircling the bottom of the sidewall member so as to securely lock the sleeve within the groove. Additionally, a plastic top portion is fitted over the top portion of the sleeve in substantially the same manner as the sleeve was fitted within the defined groove.
A dry break valve is also disclosed for use with a blow molded tank which is retained within the sleeve upon the pallet. The dry break valve insures that flow of material from within the tank will be discontinued immediately when the valve is closed.
These and other aspects, features, advantages, and objects of this invention will be more readily understood upon reviewing carefully the following detained description in conjunction with the accompanying drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention relative to the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings. In describing the overall invention, reference will be made to the accompanying drawings wherein like numerals in the various figures refer to the same or similar elements or features and in which:
FIG. 1 is an exploded perspective view showing the assembly relationship of the components of a container made in accordance with the teachings of the preferred embodiment of this invention;
FIG. 2 is a vertical sectional view of the composite container of this invention taken substantially along the line 2--2 of FIG. 1;
FIG. 3 is a fragmentary exploded perspective view showing the assembly relationship of the sleeve, pallet, and retainer clip in a container made in accordance with the teachings of the preferred embodiment of this invention;
FIG. 4 is an enlarged sectional view taken substantially along the line 4--4 of FIG. 2;
FIG. 5 is an exploded elevational and sectional view of the components associated with a dry break valve in the container of this invention;
FIG. 6 is a vertical sectional view of the dry break valve of FIG. 5 shown in assembly relation with the tank forming part of the composite container of this invention; and
FIG. 7 is a perspective view of the spring retainer portion of the dry break valve shown in FIGS. 5 and 6.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, there is shown a composite container 10 made in accordance with the teachings of the preferred embodiment of this invention and including a substantially square shaped top or cover member 12, a substantially square shaped pallet 14, a sleeve member 16 in the form of a cardboard box of rectangular shape, and a blow molded plastic tank 20 having thin walls.
Specifically as shown best in FIGS. 1 and 3, the pallet 14 comprises a plastic body having flat support portion 22 bounded by a depending sidewall member 24. Spaced support feet 25 are formed on sidewall member 24 at equi-distant locations therearound so that the container 10 can be supported on a floor or other surface and handled with fork lift or other apparatus. The sidewall member 24 further contains a plurality of rectangularly shaped side openings 30 on the outer surface thereof. A recessed groove 32 is formed around the periphery of pallet 22 at a position extending downwardly into sidewall member 24 in communication with the openings 30.
The pallet 22 also has an upwardly flanged cup shaped tank retention projection 34 having an opening 36 for the tank discharge. The pallet 22 and the projection 34 may be constructed of a variety of materials but, in the preferred embodiment of this invention, are manufactured of a thermo-formed plastic material.
The tank 20 is a generally cubic shape hollow body 38 into which a volume of flowable liquid material (not shown) is placed. In the preferred embodiment of this invention, tank 20 is manufactured by the standard technique of blow molding polyethylene. Tank 20 also contains a top inlet (not shown) in communication with the interior of body 38. The inlet is used to fill the body 38 with flowable material following which the inlet is closed by a readily removable closure 40.
Tank 20 further contains a dry break valve body 42 (shown best in FIGS. 1 and 5) which provides communication between the contained flowable material (not shown) and the exterior of tank 20 by means of an outlet opening 44 which is circumscribed by a plurality of internal threads 46 on the interior surface of valve body 42.
As shown best in FIGS. 5-7, a dry break valve assembly 48 is disposed within valve 42 and comprises a spring retention member 50, a spring 52, a depressible poppet member 54, and a removable threaded insert 56.
Retention member 50 consists of a unitary irregularly shaped body having a flat plate portion 58 formed with a central orifice 66 and having side wing portions 62 which are perpendicular to plate portion 58. Each side portion 62 is integral with opposite portions 68 and 70 which extend angularly outward relative to the supporting sidewing portion 62.
The retention member 50, in the preferred embodiment of this invention, is disposed within valve 42 such that orifice 60 is in direct communication with outlet 44. This location is accomplished by positioning angle portions 68 and 70 on an interior shoulder 72 in valve body 42 as shown in FIG. 6.
Spring 52 is a standard compressible spring and is of a diameter such that it can be positioned at one end 76 between the side portions 62 of retention member 50 in the manner illustrated in FIG. 6. The opposite end 78 of spring 52 is wrapped around a horizontally extending projection 80 on poppet 54 and is moveable from an extended partially compressed position as shown in FIG. 6 to a more compressed "valve open" position (not shown).
Poppet 54 has an end face 82 which defines an area large enough to cover outlet opening 44. As shown in FIG. 6, poppet 54 is normally biased into a fluid stoppage position by the co-operation of spring 52 and shoulder 72.
In this stoppage position, communication is prevented between the material (not shown) in tank 20 and outlet opening 44. Poppet 54 is moveable to a depressed or valve open position (further within the body of valve 42) by the application of depressing force to face 82. When enough force is applied to face 82 to overcome the force of the spring 52, the poppet 54 is moved into an internal chamber 84 within valve body 42.
In this position, the valve is open and material can flow from tank 20 to outlet 44 as the material will now flow around poppet 54 through the chamber 84 and exiting therefrom through outlet 44. If the depressing force applied to face 82 is removed, spring 52 will move the poppet 54 back to an operable stoppage position as shown in FIG. 6. Thus, an interruption or breakage of contact between poppet 54 and a valve opening member (not shown) will not result in spillage of the tank contents because the valve 48 will automatically close. Threaded insert 56 is provided to support poppet 54 so that poppet 54 may not be accidentally depressed in a manner that would cause material flow from outlet 44.
As shown in FIG. 1, the tank 20 is peripherally supported by sleeve 16 which is telescoped over the tank 20. Specifically, sleeve 16 has rectangular flat side walls 86, a front wall 87 and a back wall 89, each having a horizontal bottom edge 88 adapted to be placed within groove 32 so as to support the sleeve 16 on the pallet 14. In the preferred embodiment of the invention, sleeve 16 is made of corrugated cardboard.
As shown best in FIGS. 1 and 3, each sidewall 86 has a plurality of rectangular openings 90 therein, said openings 90 being disposed adjacent horizontal top and bottom edges 92 and 88, respectively of the sidewall. A centrally located opening 94 in the front wall 87 is aligned with the tank discharge opening 44.
As further shown in FIG. 1, container 10 also includes a top or cover 12 preferably manufactured of thermo-formed plastic and defining a flat depressed inner portion 98 having a central opening 100. A thick peripheral ridge 102 extending around the cover periphery has a plurality of openings 104 on sides 106 that are aligned with side walls 86.
As shown best in FIGS. 3 and 4, the container 10 is maintained in assembled condition by a plurality of locking clips 108 preferably formed of a yieldable plastic material. Each clip 108 has an upright outer wall 110 to which horizontal finger members 112 and 114 are connected. The lower finger 114 terminates at its inner end in a vertical flange 116 which extends upwardly and ends in a spaced relation with upper finger 112. The outer side of flange 116 terminates in a beveled face 118 for a purpose to appear presently.
The clip 108 is constructed so that the finger 112 can be inserted into one of the pallet openings 30 and through a sidewall of opening 90 aligned with opening 30 while lower edge 88 of sidewall 86 is supportively nested within pallet groove 32. The beveled face 118 of finger 114 engages a surface 122 on the bottom portion of sidewall member 24 inwardly of the opening 30 so that the flange 116 is deflected downwardly below the sidewall 24 until it has cleared the sidewall. The flange 116 then springs upwardly to the locking position shown in FIG. 4.
In operation, top 40 is twistably lifted from tank 20 and flowable material (not shown) is placed within body 38. Top 40 is then returned to its closure position, as shown in FIG. 1, and tank 20 is placed upon support portion 22 of pallet 14 such that discharge 44 is placed within recess 36 and extends forwardly therefrom. The tank 20 is then nested in retention projection 34. Sleeve 18 is then telescoped downwardly over the tank 20 and extended into groove 32 such that each opening 90 adjacent lower edge 88 is in direct communication with a pallet opening 30. A locking clip 108 is then inserted into every opening 30 such that finger 112 thereof extends through an opening 90 and the bottom edge of the sleeve 16 is nested within groove 32 wherein finger portion 116 of clip 108 simultaneously is locked against the inner side of the sidewall 24 of pallet 14. In this manner, the sleeve 16 is securely connected to pallet 14 so as to retain the tank 20 in an upright position on the pallet.
The cover 12 is then positioned over the top end of sleeve 16 and is secured by clips 108, turned upside down relative to the position shown in FIGS. 3 and 4, to the upper edge 92 of the sleeve 16. In this assembly, opening 100 is aligned with the tank closure 40 so that the tank 20 can be filled through the opening 100 after the cover 12 is installed. The container 10 is readily discharged through dry break valve body 42 and sleeve opening 94 by actuation of the dry break valve poppet 54.
Should it be desired to remove tank 20 from container 10, clips 108 are first removed and sleeve 16 together with top 12 are removed exposing tank 20. Thusly, based upon the aforementioned discussion it should be apparent to one skilled in the art that container 10 is relatively easy to assemble or to disassemble and that the repeated insertion or removal of clips 108 therefrom will have little effect upon the wear of the same thus increasing the total useable life of container 10. Further, container 10 may be stacked in a relatively small warehouse space and contains elements including a pallet which may be repeatedly used.
It is to be understood that the invention is not to be limited to the exact construction or method illustrated and described above, but that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.
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A composite container which consists of a reusable pallet, a thin walled plastic tank and a reinforcing cardboard shell maintaining the tank in an upright position on the pallet. Plastic clips connect the shell to the pallet and enable easy assembly and disassembly of the container. Additionally, a dry break valve is incorporated in the container so as to prevent material leakage and enable easy discharge of the tank contents on an intermittent basis.
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RELATED APPLICATIONS
This application is related by Applicant's copending application Ser. No. 781,338 filed on June 6, 1986.
FIELD OF THE INVENTION
This invention relates to an ocean-floor wellhead apparatus for use in drilling offshore oil and gas wells in combination with means for sinking it into the ocean floor and drilling a well therethrough.
BACKGROUND OF THE INVENTION
Deepwater wellheads of oil and gas wells are generally put in place by lowering a drill string having a bit at the bottom, boring hole in the ocean floor, and lowering a wellhead apparatus down the drill string. A large-diameter length of pipe is generally secured to the bottom of the wellhead, lowered into the drilled hole and centered therein.
Housing for wellhead equipment may consist of a subsea caisson having an open bottom that is lowered to the ocean floor and a pressure displacement dredging system to remove the soil inside the caisson. Such a device is set forth in U.S. Pat. No. 4,558,774 issued on Dec. 17, 1985. However, in this patent, apparatus in the caisson is used to remove the soil against its inner walls which eliminates soil friction inside the caisson which is positioned below the ocean floor.
It is also recognized that ship anchors have been positioned in the ocean floor by sucking them into the ocean floor in accordance with the method and apparatus disclosed in U.S. Pat. No. 4,432,671 issued on Feb. 21, 1984. However, the apparatus of this invention requires the use of a specially designed underwater motor-driven pump together with power-transmission cables which are removably connected to the anchor prior to installing the anchor in the ocean floor, and subsequently remotely disconnected from the anchor for removal to the ocean surface.
It is an object of the present invention to provide a well base structure that is highly stable, capable of taking high vertical and lateral loads, and can be controlled during installation to be either truly plumb or positioned at a predetermined angle relative to the vertical. Another object of the present invention is to provide an underwater wellhead apparatus that can be transported to the drilling location on a relatively small vessel and lowered to the ocean floor by means of a running pipe string. The apparatus, upon being positioned on the ocean floor, is subsequently sucked into the ocean floor by means of circulating fluid, such as water, down the running pipe string to actuate a suction device carried by the wellhead apparatus. The apparatus is anchored in the ocean floor by frictional resistance against both the internal and external walls of the apparatus. The apparatus is further provided with means whereby a well may be drilled through it into the ocean floor.
SUMMARY OF THE INVENTION
This invention relates to a wellhead apparatus and a method for positioning the apparatus on the ocean floor in combination with means for sinking it into the ocean floor. The wellhead apparatus is equipped with a venturi suction device and a central opening for receiving a well conductor.
A venturi suction device is provided on or stabbed into an open-bottom container assembly or arrangement of containers so that the suction device may be placed in fluid communication with ports through the upper end of the container assembly. The suction device may be conducted to a running pipe string used for lowering the wellhead apparatus from a vessel on the water surface to the ocean floor and sinking it thereinto.
Once the wellhead apparatus is lowered to the ocean floor, the angle of the wellhead apparatus relative to the vertical is determined. This may be done in any well-known suitable manner, as by a camera carried by an underwater remotely-operated vehicle (ROV) or a level-indicating device positioned on the wellhead apparatus. It may be desirable in some locations to position the wellhead apparatus at an angle, say 10 to 20 degrees, with respect to the vertical, such as in the case where the wellhead apparatus is to be positioned on the ocean floor so as to drill a well beneath a shipping lane in which a drilling vessel may not be positioned. If a level-indicating device is employed, it may be connected to a controller located on the apparatus or aboard a vessel from which, in turn, a signal can be transmitted to actuate valves carried by the container assembly for adjusting the wellhead apparatus to a predetermined angle relative to the vertical.
By means of a pump on the surface vessel, fluid is pumped down the running string, through the venturi of the suction device, and out an outlet port of the suction device so as to create suction within the container assembly. The suction is terminated by shutting off the pump on the surface vessel when the container assembly has penetrated the ocean floor to a selected depth.
The venturi suction device is then disconnected from the container assembly and raised with the running string to the water surface. Alternatively, the remaining pipe string may be disconnected from the venturi suction device which could be left on the container assembly.
A well conductor is then lowered from the surface vessel through the central opening of the wellhead apparatus to be seated on landing surfaces formed or supports connected to the container assembly which have a downwardly-directed opening therethrough.
An advantage of the present invention is that a solidly anchored wellhead apparatus may be positioned on the ocean floor to serve as a base for subsea drilling and/or production facilities such as drilling wellhead assembly which may include connectors, blow out preventers, etc. of a type well known to the art and used in drilling underwater wells.
Another advantage of the present invention is that it is not necessary to drill a hole in the ocean floor prior to installing the underwater wellhead or the platform on which the underwater wellhead is securely positioned during the drilling of a well.
A further advantage of the present invention is that it permits the drilling of a well into the ocean floor at a predetermined angle, say two to twenty degrees from the vertical. The present method and apparatus provides means for positioning an offshore wellhead at a selected angle relative to the vertical.
The various features of novelty which characterize the invention are pointed out with particularity in the claims forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific object obtained by its uses, references should be made to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.
A BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view, taken in partial cross-section, of a wellhead apparatus after it has been sucked into the ocean floor;
FIG. 2 is a plan view of another embodiment of a wellhead apparatus having a base plate for supporting well equipment;
FIG. 3 is a cross-sectional view taken along the line 3--3 of FIG. 2 of a pendulum device used to control evacuation of water from a wellhead apparatus; and
FIG. 4 is a schematic view of a level-indicating device, controller, and remotely-actuated valves on the wellhead apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 of the drawing, a wellhead apparatus represented herein by numeral 10, may comprise a plurality of open-bottomed containers 15 adapted to be sunk into the ocean floor 11 such that the tops of the containers are above the ocean floor 11 to form a base for well equipment. The container edges, when penetrating the ocean floor 11, provide a seal limiting the entry of water into the containers 15.
A venturi suction device 30 is engageable and disengageable with the wellhead apparatus 10. The suction device 30 has a throughbore 32 and is secured to and lowered by a conduit 40, such as running pipe string, extending from the ocean floor 11 to a point above the water surface. The suction device 30 may be provided with means for seating the suction device 30 adjacent the top of the container 15 and means for orienting and aligning the ports 45 of the suction device with the ports 27 of the sleeve 26.
The container 15 shown in FIG. 1 is provided with a landing surface 25 to engage a well conductor (not shown) or the landing surface 22 of the suction device 30. The sleeve 26 of the container 15 is centrally positioned in the wellhead apparatus 10 and extends downwardly from the landing surface 25 of the container 15. The sleeve 26 has ports 27 through the wall near the upper end of the container 15 and is in communication with the interior of the container 15. The top of the sleeve is formed in a manner to receive the suction device 30 and is lowerable by the conduit 40 from a vessel on the ocean surface or by other suitable means.
Suitable cooperating connector means, diagrammatically represented by numeral 42, carried by the suction device 30 and wellhead apparatus 10 connects the wellhead apparatus 10 to the suction device 30 in a weight-supporting and fluid-communication manner. Alternatively, the connector means 42 may have two engageable portions, one portion being carried by the suction device 30 and the other portion being carried by the upper end of the sleeve 26 of the wellhead apparatus 10.
Fluid conduit means 44 of the suction device 30 are in communication with the interior of the container 15 and the venturi suction ports 45. The fluid conduit means 44 include at least one port 27 through the wall of the container 15 near its upper end.
A base 17, as shown in FIG. 2, may be connected to the tops of a plurality of containers 15 to provide a surface for supporting equipment associated with the use of the wellhead apparatus 10. Holes 18 may be provided in the base 17 to permit the base 17 to be more easily lowered from a vessel on the water surface to the ocean floor 11. The plurality of containers 15 shown in FIG. 2 are positioned in the ocean floor 11 in close fixed proximity to each other. Support means 20, such as a substantially horizontal plate, is secured to the containers forming the wellhead apparatus 10 and has a downwardly directed opening 21 therethrough for receiving a well conductor.
The suction device 30 may comprise a pendulum-type valve, flow controller, or adjustable closure device 47 (FIG. 3) to selectively open the suction ports 34 in response to the angle of the containers 15 relative to the vertical during normal operations in the illustrated embodiment of FIG. 3, the pendulum-type valve has a pendulum 47a suspended from a conduit 40 by a suspending support 47B.
FIG. 4 illustrates a wellhead apparatus 10 including level-indicating means 50 in communication with the containers 15 to determine the angle of the containers 15 relative to the vertical. The level-controlling system may include level-indicating means 50, valves 52 connected in communication with the ports 53 of the containers 15 for selectively evacuating water from the selected containers 15, and controller means 55 in communication with the level-indicating means 50 and the valves 52 to selectively open the valves 52 based on the desired angle that the containers 15 are to be positioned relative to the vertical.
Referring to FIG. 1, the method for positioning the wellhead apparatus 10 and sinking it into the ocean floor 11, comprises the initial step of connecting the suction device 30 to the lower end of the conduit 40 in a manner such that the suction device 30 is in fluid communication with the container 15. That is, the suction device 30 is seated and aligned with the container 15 so that one suction port 45 is in communication with the container port 27 and the other suction port 34 is in communication with the throughhole 32 of the conduit 40. Conduit 40 may be added until the wellhead apparatus 10 is on the ocean floor 11.
Then, it is determined whether the container 15 is at the desired angle relative to the vertical. This may be done in any manner well known to the art such as a camera carried by an underwater remotely-operated vehicle (ROV) or a level-indicating device 50 (FIG. 4). A signal is transmitted from the level-indicating means 50 to a controller means 55 to indicate the angle of the containers 15 relative to the vertical. The position indicated by the controller means 55, located on the apparatus 10 or aboard a service vessel, for example, is compared with a selected predetermined angle of the containers 15 relative to the vertical. If angular adjustment of the containers 15 is necessary, a signal is transmitted from the controller means 55 to actuate the valve means 52 carried by the container 15 selectively according to the desired angle of the containers 15 relative to the vertical.
To sink the container 15 into the ocean floor 11 to a selected depth (FIG. 1), fluid is pumped down the conduit 40, through the venturi suction device 30, and out of the outlet port means 37 to create suction within the container 15. The wellhead apparatus 10 is anchored in the ocean floor 11 by frictional resistance against both the internal and external walls of the container 15. Should it become necessary to adjust the angle of the wellhead apparatus 10 relative to the vertical after the apparatus 10 has been sunk into the ocean floor 11, fluid may be pumped down the conduit 40 and into the apparatus 10 to increase the pressure within the apparatus 10 to release the suction within the container 15. When the container 15 has sunk into the ocean floor to a selected depth and angle, the suction within the container 15 is terminated and the suction device 30 is disconnected from the container 15. The suction device 30 and associated conduit 40 are then raised to the water surface. Alternatively, the conduit 40 may be disconnected from the suction device 30 which could be left on the wellboard apparatus 10.
A well conductor (not shown) is then lowered from the surface vessel through the central opening of the wellhead apparatus 10 to be seated on the landing surfaces 25 of the container 15 having a downwardly-directed opening therethrough.
Alternatively, the apparatus 10 may be positioned on the ocean floor 11 in accordance with the present invention to serve as a base for subsea drilling and production facilities such as a template (not shown) for drilling a multiplicity of wells, or as an ocean-floor base for oil and/or gas manifold systems, production or separator equipment, underwater storage facilities, pipelines, underwater mining facilities, etc.
Thus, it can be seen that the above-mentioned objective may be accomplished, based on the description of the preferred embodiment, by practicing the above-mentioned method.
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A wellhead apparatus and a method for positioning the apparatus on the ocean floor in combination with means for sinking it into the ocean floor. The wellhead apparatus is equipped with a venturi suction device and a central opening for receiving a well conductor pipe. The apparatus provides a well base structure that is highly stable, capable of taking high vertical and lateral loads, and can be controlled during installation to be either truly plumb or positioned at a predetermined angle relative to the vertical.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a continuation-in-part application of co-pending U.S. patent application Ser. No. 14/708,883, filed May 11, 2015, which is a continuation of U.S. patent application Ser. No. 13/428,625, filed Mar. 23, 2012, now U.S. Pat. No. 9,057,185, which claims the benefit of U.S. Provisional Patent Application No. 61/467,858, filed Mar. 25, 2011, and 61/490,138, filed May 26, 2011, all of which are incorporated by reference in their entireties herein.
BACKGROUND
[0002] Sinks have drains for permitting water to drain from the sink into a plumbing system. During installation, drains are typically inserted into the interior of the sink basin and dropped into an opening at the base of the basin. The drain has a rim with a diameter exceeding the diameter of the opening such that the rim rests on the top surface of the base of the sink basin. Often, the portion of the base surrounding the opening has a countersink portion such that the rim of the drain is generally flush with the adjacent portion of the base of the sink. Nonetheless, a groove is present between the rim of the drain and the sink base that is difficult to clean and susceptible to bacterial growth. In addition, the presence of the groove is visible to a user and aesthetically unappealing.
BRIEF SUMMARY
[0003] Embodiments of sinks and drains for sinks are disclosed herein. The embodiments permit the attachment of a drain to a sink such that the drain is substantially disposed below the top surface of the sink basin, and such that there is no discernable separation between the base of the sink basin and the drain when viewed from above the sink. A method of making a sink is also disclosed wherein there is no discernable separation between the base of the sink basin and the drain when viewed from above the sink.
[0004] A sink is described comprising a sink basin having a sidewall and a base in a bottom portion thereof. The base includes a drain opening and a first drain entry portion integrally formed from the base and extending from the bottom portion at the drain opening. A second drain entry portion includes a first end portion with a radially outwardly extending flange configured to connect to the base at the first drain entry portion, and a second end portion opposite the first end portion. A bracket includes a lip configured to engage the flange. A fastener attaches the bracket to the base to thereby hold the first end of the second drain entry portion to the first drain entry portion with the lip engaged with the flange.
[0005] A method of making a sink is also described. The method comprises forming a sink basin having a sidewall and a base, the base including a bottom portion and an opening. A first drain entry portion is formed integrally with the base and extending from the bottom portion at the drain opening. A second drain entry portion is provided, the second drain entry portion including a first end portion with a radially outwardly extending flange. A bracket including a lip is positioned into engagement with the flange to hold the flange on the base at the first drain entry portion. The bracket is attached to the base to thereby hold the first end of the second drain entry portion to the first drain entry portion with the lip engaged with the flange.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a perspective view of a sink;
[0007] FIG. 2 is a sectional view of a drain for the sink of FIG. 1 ;
[0008] FIG. 3 is a sectional view of a second embodiment of a drain for the sink of FIG. 1 ;
[0009] FIG. 4 is a sectional view of a third embodiment of a drain for the sink of FIG. 1 ;
[0010] FIG. 5 is a perspective view of another embodiment of a sink;
[0011] FIG. 6 is a sectional view of an embodiment of a drain for the sink of FIG. 5 ;
[0012] FIG. 7 is a sectional view of an embodiment of a drain for a sink attached to a garbage disposer;
[0013] FIG. 8 is a fragmentary bottom perspective view showing the drain of FIG. 7 ;
[0014] FIG. 9 is a sectional view of a drain entry portion welded to a sink;
[0015] FIG. 10 is a sectional view of another embodiment of a drain entry portion welded to a sink;
[0016] FIG. 11 is a sectional view of a further embodiment of a drain entry portion welded to a sink;
[0017] FIG. 12 is a cross section view of a sink;
[0018] FIG. 13 is a sectional close up view of a drain of the sink of FIG. 12 ;
[0019] FIG. 14 is a sectional close up view of an embodiment of a fastener for attaching a drain to a sink;
[0020] FIG. 15 is a sectional close up view of another embodiment of a fastener for attaching a drain to a sink;
[0021] FIG. 16 is a sectional close up view of yet another embodiment of a configuration for attaching a drain to a sink;
[0022] FIG. 17 is a sectional close up view of yet another embodiment of a configuration for attaching a drain to a sink;
[0023] FIG. 18 is a sectional close up view of yet another embodiment of a fastener for attaching a drain to a sink;
[0024] FIG. 19 is a perspective close up view of yet another embodiment of a configuration for attaching a drain to a sink;
[0025] FIG. 20 is a perspective view of a portion of the configuration of FIG. 19 ; and
[0026] FIG. 21 is a sectional close up view of yet another embodiment of a configuration for attaching a drain to a sink.
DETAILED DESCRIPTION
[0027] Referring to FIG. 1 , a sink 100 with the appearance of an edgeless drain is shown. The sink 100 can include one or more sink basins 102 and a rim 104 . The sink basin 102 can include one or more sidewalls 106 and a base 108 . The base 108 can include an opening 110 for a drain. The sidewalls 106 and base 108 can form an interior surface of the basin 102 to retain water and washable items. The rim 104 can be used to support the basin 102 in an above-mount arrangement or under-mount arrangement with respect to a counter. The sink 100 can be made of any suitable material, such as stainless steel.
[0028] Referring to FIG. 2 , a drain 101 is shown that can include a drain entry portion 112 , and drain elements including a flange plate 114 , a strainer 116 , a drain pipe 118 , and a cover 120 . The drain entry portion 112 can be sized and shaped to receive at least one of the drain elements and preferably all of the above drain elements, for example a cylindrical shape and can extend from the bottom of the sink basin at the opening for the drain 101 . The drain entry portion 112 can include a first end portion 122 and a second end portion 124 . In some embodiments, the drain entry portion 112 can be formed as part of the sink 100 . In other embodiments, the drain entry portion 112 can be a component separately manufactured from the sink 100 . The first end portion 122 of the drain entry portion 112 can be welded to the base of the sink to fix the drain entry portion 112 to the sink basin at the opening. In order to conceal the welded intersection between the drain entry portion 112 and the base, a grinding and polishing operation can be applied such that the intersection is hidden to a user looking into the sink basin. In addition, because the drain entry portion 112 can be mounted from below without the need for a drain rim to rest on the base, there is no groove between the drain 101 and the sink basin 102 . From a user's perspective, the drain opening leads directly into the drain 101 . The weld between the sink basin and the drain entry portion 112 can be accomplished in any suitable manner, such as with a shielding gas weld.
[0029] FIGS. 9-11 show examples of suitable embodiments of a drain entry portion welded to a base of a sink. It will be appreciated, however, that the drain entry portion can be coupled to the sink via any suitable manner, some embodiments of which are illustrated herein.
[0030] Referring to FIG. 9 , the drain entry portion 612 can include a radially extending flange 680 . The flange 680 can be disposed against the underside of the sink base 108 . The drain entry portion 612 can have an interior diameter that is smaller than the opening 110 of the sink 100 such that there is a portion of the flange 680 extending inward from the opening 110 that can receive a solder material 682 for welding the drain entry portion 612 to the sink 100 . As discussed, after welding, a grinding and polishing operation can be applied to the weld such that the intersection between the drain entry portion 612 and the sink 100 is hidden to a user looking into the sink basin 102 .
[0031] Turning to FIG. 10 , the drain entry portion 712 can include a radially extending flange 780 . The flange 780 can be disposed within the opening 110 such that the flange abuts the portion of the sink base 108 forming the opening 110 . Thus, the perimeter of the flange 780 has a diameter that is smaller than the opening 110 of the sink 100 such that the flange 780 fits within the opening 110 . The thickness of the flange 780 can be smaller than the thickness of the sink base 108 such that a space is formed on the upper surface of the flange 780 for receiving a solder material 782 for welding the drain entry portion 712 to the sink 100 . As discussed, after welding, a grinding and polishing operation can be applied to the weld such that the intersection between the drain entry portion 612 and the sink 100 is hidden to a user looking into the sink basin 102 .
[0032] As shown in FIG. 11 , the drain entry portion 812 can include a radially extending flange 880 . The flange 880 can be disposed away from the edge 884 of the drain entry portion 812 on the first end portion 822 . The flange 880 can be disposed against the underside of the sink base 108 , and the edge 884 of the drain entry portion 812 can have an exterior diameter that is smaller than the opening 110 of the sink 100 . The flange 880 can be located on the drain entry portion 812 a sufficient distance from the edge such that the edge is disposed below the upper surface of the sink base 102 and such that the edge 884 can receive a solder material 882 for welding the drain entry portion 812 to the sink 100 . As discussed, after welding, a grinding and polishing operation can be applied to the weld such that the intersection between the drain entry portion 812 and the sink 100 is hidden to a user looking into the sink basin 102 .
[0033] Referring again to FIG. 2 , the second end portion 124 of the drain entry portion 112 can include a lip 126 for receiving a seal 128 . The flange plate 114 can have an outer edge portion 130 and an inner edge portion 132 . The outer edge portion 130 of the flange plate 114 can rest on the seal 128 such that the seal 128 prevents water inside the drain 101 from passing between the intersection of the drain entry portion 112 and the flange plate 114 . The inner edge portion 132 of the flange plate 114 can receive a lip 134 of the drain pipe 118 for supporting the drain pipe 118 .
[0034] The strainer 116 can be disposed above the lip 134 of the drain pipe 118 and the inner edge portion 132 of the flange plate 114 . The strainer 116 can include a seal 136 for contacting the lip 134 of the drain pipe 118 and preventing the passage of water in the drain 101 past the seal 136 . The strainer 116 can be press fit within the flange plate 114 . The strainer 116 can have one or more openings in the bottom of the strainer to permit water to flow past the strainer 116 and into the drain pipe 118 .
[0035] The drain 101 can include a cover 120 over the drain entry portion 112 , the flange plate 114 , and the strainer 116 . The cover 120 can be secured to the sink with a locking nut 138 . The drain pipe 118 can be threaded to receive the locking nut 138 , and the locking nut 138 can be tightened to enhance the seal force applied between the drain entry portion 112 and the flange plate 114 . A coupler 140 can be used to attach the drain pipe 118 to a pipe 142 leading to a trap.
[0036] A removeable strainer basket 144 can be disposed within the drain 101 . The strainer basket 144 can include a basket portion 146 for capturing solids and a stopper 148 that can be lowered into the strainer 114 to plug the drain 101 .
[0037] Turning to FIG. 3 , a second embodiment of a drain 201 is shown that can include a drain entry portion 212 , and an attachment portion 250 , and drain elements including a strainer 216 , and a drain pipe 218 . The drain entry portion 212 can be cylindrical and can extend from the bottom of the sink basin at the opening for the drain 201 . The drain entry portion 212 can include a first end portion 222 and a threaded exterior surface 252 . The drain entry portion 212 can be a component separately manufactured from the sink. The first end portion 222 of the drain entry portion 212 can be welded to the base to fix the drain entry portion 212 to the sink basin at the opening. In order to conceal the welded intersection between the drain entry portion 212 and the base, a grinding and polishing operation can be applied such that the intersection is hidden to a user looking into the sink basin. In addition, because the drain entry portion 212 can be mounted from below without the need for a drain rim to rest on the base, there is no groove between the drain 201 and the sink basin. From a user's perspective, the drain opening leads directly into the drain 201 . The weld between the sink basin and the drain entry portion 212 can be accomplished in any suitable manner, such as with a shielding gas weld.
[0038] The attachment portion 250 can have a threaded surface 254 and an inner edge portion 232 . The attachment portion threaded surface 254 can be received and tightened to the threaded surface 252 of the drain entry portion 212 . The inner edge portion 232 of the attachment portion 250 can receive a lip 234 of the drain pipe 218 for supporting the drain pipe 218 .
[0039] The strainer 216 can be disposed above the lip 234 of the drain pipe 218 and the inner edge portion 232 of the attachment portion 250 . The strainer 216 can include a seal 236 for contacting the lip 234 of the drain pipe 218 and preventing the passage of water in the drain 201 past the seal 236 . The strainer 216 can be press fit within the attachment portion 250 . The strainer 216 can have one or more openings in the bottom of the strainer to permit water to flow past the strainer 216 and into the drain pipe 218 . The drain pipe 218 can be threaded to receive a coupler that can be used to attach the drain pipe to a pipe leading to a trap.
[0040] A removeable strainer basket 244 can be disposed within the drain 201 . The strainer basket 244 can include a basket portion 246 for capturing solids and a stopper 248 that can be lowered into the strainer 216 to plug the drain 201 .
[0041] Referring to FIG. 4 , a third embodiment of a drain 301 is shown that can include a drain entry portion 312 , an attachment portion 350 , and drain elements including a strainer 316 , and a drain pipe 318 . The drain entry portion 312 can be cylindrical and can extend from the bottom of the sink basin at the opening for the drain 301 . In this embodiment, the drain entry portion 312 can be formed from the sink basin during the drawing process to shape the sink. Thus, the drain entry portion 312 can be integrally formed to lead directly from the sink basin to the drain 301 . Threads 352 can be welded or otherwise attached to the drain entry portion 312 .
[0042] The attachment portion 350 can have a threaded surface 354 and an inner edge portion 332 . The attachment portion threaded surface 354 can be received and tightened to the threads 352 of the drain entry portion 312 . The inner edge portion 332 of the attachment portion 350 can receive a lip 334 of the drain pipe 318 for supporting the drain pipe 318 .
[0043] The strainer 316 can be disposed above the lip 334 of the drain pipe 318 and the inner edge portion 332 of the attachment portion 350 . The strainer 316 can include a seal 336 for contacting the lip 334 of the drain pipe 318 and preventing the passage of water in the drain 301 past the seal. The strainer 316 can be press fit within the attachment portion 350 . The strainer 316 can have one or more openings in the bottom of the strainer to permit water to flow past the strainer 316 and into the drain pipe 318 . The drain pipe 318 can be threaded to receive a coupler that can be used to attach the drain pipe to a pipe leading to a trap.
[0044] A removeable strainer basket 344 can be disposed within the drain 301 . The strainer basket 301 can include a basket portion 346 for capturing solids and a stopper 348 that can be lowered into the strainer 316 to plug the drain 301 .
[0045] FIGS. 5 and 6 show another embodiment of an edgeless drain 401 suitable for use with a non-metallic sink 400 , such as a sink made of granite or other suitable stone. The drain 401 can include a first drain entry portion 411 , a second drain entry portion 412 , and drain elements including a flange plate 414 , a strainer 416 , a drain pipe 418 , and a cover 420 . The first drain entry portion 411 can be cylindrical and can extend from the bottom of the sink basin at the opening for the drain 401 . Similar to the embodiment of FIG. 4 , the first drain entry portion 411 can be formed as part of the sink basin during the process of making the sink. Thus, the first drain entry portion 411 leads directly from the sink basin into the drain 401 .
[0046] The second drain entry portion 412 can include a first end portion 422 and a second end portion 424 . The second drain entry portion 412 can be a component separately manufactured from the sink. The first end portion 422 of the second drain entry portion 412 can include one or more apertures such that the drain entry portion 412 can be fastened to the bottom of the sink using suitable fasteners 456 disposed through the apertures, such as one or more screws.
[0047] The second end portion 424 of the second drain entry portion 412 can include a lip 426 for receiving a seal 428 . The flange plate 414 can have an outer edge portion 430 and an inner edge portion 432 . The outer edge portion 430 of the flange plate 414 can rest on the seal 428 such that the seal 428 prevents water inside the drain 401 from passing between the intersection of the second drain entry portion 412 and the flange plate 414 . The inner edge portion 432 of the flange plate 414 can receive a lip 434 of the drain pipe 418 for supporting the drain pipe 418 .
[0048] The strainer 416 can be disposed above the lip 434 of the drain pipe 418 and the inner edge portion 432 of the flange plate 414 . The strainer 416 can include a seal 436 for contacting the lip 434 of the drain pipe 418 and preventing the passage of water in the drain 401 past the seal 436 . The strainer 416 can be press fit within the flange plate 414 . The strainer 416 can have one or more openings in the bottom of the strainer to permit water to flow past the strainer 416 and into the drain pipe 418 .
[0049] The drain 401 can include a cover 420 over the second drain entry portion 412 , the flange plate 414 , and the strainer 416 . The cover 420 can be secured to the sink with a locking nut 438 . The drain pipe 418 can be threaded to receive the locking nut 438 , and the locking nut 438 can be tightened to enhance the seal force applied between the second drain entry portion 412 and the flange plate 414 . A coupler 440 can be used to attach the drain pipe 418 to a pipe 442 leading to a trap.
[0050] A removeable strainer basket 444 can be disposed within the drain 401 . The strainer basket 444 can include a basket portion 446 for capturing solids and a stopper 448 that can be lowered into the strainer 416 to plug the drain 401 .
[0051] It will be appreciated that the above-described sink and drain embodiments may be utilized with a garbage disposer. For example, FIGS. 7 and 8 show an embodiment of a drain 501 attached to a garbage disposer 560 . In this embodiment, the drain 501 can include a drain entry portion 512 , a disposer attachment ring 562 , a strainer 516 , and a disposer assembly 564 . The drain entry portion 512 can be cylindrical and can extend from the bottom of the sink basin at the opening for the drain 501 . The drain entry portion 512 can include a first end portion 522 and a threaded exterior surface 552 . The drain entry portion 512 can be a component separately manufactured from the sink. The first end portion 522 of the drain entry portion 512 can be welded to the base to fix the drain entry portion 512 to the sink basin at the opening. In order to conceal the welded intersection between the drain entry portion 512 and the base, a grinding and polishing operation can be applied such that the intersection is hidden to a user looking into the sink basin. In addition, because the drain entry portion 512 can be mounted from below without the need for a drain rim to rest on the base, there is no groove between the drain 501 and the sink basin. From a user's perspective, the drain opening leads directly into the drain 501 . The weld between the sink basin and the drain entry portion 512 can be accomplished in any suitable manner, such as with a shielding gas weld.
[0052] The disposer attachment ring 562 can have a threaded surface 566 and a lower portion 568 . The flange plate threaded surface 552 can be received and tightened to the threaded exterior surface 566 of the drain entry portion 512 . The lower portion 568 can have a detent 570 for receiving a snap ring 572 . The strainer 516 can be disposed above detent 570 . The strainer 516 can have one or more openings in the bottom of the strainer to permit water to flow past the strainer 516 and into the disposer 560 .
[0053] The disposer assembly 564 can include a backup flange 574 and a mounting ring 576 . The backup flange 574 can be generally triangular and the mounting ring 576 can have a plurality of tightening screws 578 for contacting the backup flange 574 near each vertex of the backup flange 574 . During tightening of the screws 578 , the mounting ring 576 can be retained to the disposer attachment ring 562 by the snap ring 572 . As is known to those of skill in the art, the disposer 560 can include a bracket for hanging the disposer from the mounting ring.
[0054] A removeable strainer basket 544 can be disposed within the drain 501 . The strainer basket 544 can include a basket portion 546 for capturing solids and a stopper 548 that can be lowered into the strainer 516 to plug the drain 501 .
[0055] FIGS. 12-21 show a variety of alternative sink/drain attachment embodiments. In particular, sinks constructed of composite materials that are cast or molded, such as E-Granite™ and other similar materials, are particularly well suited to the illustrated attachment embodiments. One such sink 900 is shown in FIG. 12 with the configuration of an edgeless drain. Other similar sink configurations are contemplated. The sink 900 can include one or more sink basins 902 and a rim 904 . The sink basin 902 can include one or more sidewalls 906 and a base 908 . The base 908 can include an opening 910 for a drain. The sidewalls 906 and base 908 can form an interior surface of the basin 902 to retain water and washable items. The rim 904 can be used to support the basin 902 in an above-mount arrangement or under-mount arrangement with respect to a counter. The sink 900 can be made of any suitable material, such as a composite stone and acrylic resin matrix. One advantage of such an engineered, molded product is that the area surrounding the opening 910 may be provided with an increase in material thickness relative to the sidewalls 906 , which is sufficiently thick to receive fasteners or other fastening elements as will be described in more detail hereinbelow in order to fasten a drain entry portion 912 of a drain thereto. For clarity, many of the elements of the drain will be omitted in the following illustrations, and it will be understood that the drain elements shown in the previous drawings and described above may be used in conjunction with the drain entry portion 912 shown in FIG. 13 , and similar elements in the following embodiments labeled as element 1212 , 1312 , 1412 , or 1512 , for example.
[0056] FIG. 13 shows a portion of a sink base 908 according to the embodiment of FIG. 12 . The base 908 includes an opening 910 , which is formed in a portion of the base that is thicker relative to the surrounding material. The thickened section of the base 908 is drilled and tapped or otherwise provided with threads or the like to receive fasteners 956 , which may be threaded screws. The fasteners 956 , when installed, hold a bracket 984 in position against the underneath of the base 908 surrounding the opening 910 . The bracket 984 may be circular, rectangular, or any suitable shape. An optional gasket 988 may be installed between the base 908 and the bracket 984 . The bracket 984 includes a lip 986 that defines, with the base 908 , an annular channel or groove.
[0057] The sink 900 includes a first drain entry portion 911 and a second drain entry portion 912 sized and shaped to receive drain elements, some examples of which are set out in the above embodiments. The second drain entry portion 912 includes a first end portion 922 that is positionable adjacent the base 908 and a second end portion 924 that is at an opposite end of the first end portion. The second drain entry portion 912 is similar in construction, shape and size as the second drain entry portion 412 in FIG. 6 . The first end portion 922 includes a radially outwardly extending flange 980 . The diameter of the second drain entry portion 912 may match or be about that of the diameter of the opening 910 . The flange 980 extends radially outwardly from the first end portion 922 . The second drain entry portion 912 is held in position on the base 908 by the overlapping interconnection of the flange 980 and the lip 986 .
[0058] Connection of the second drain entry portion 912 to the sink 900 proceeds by positioning the second drain entry portion on the underside of the base 908 of the sink. The bracket 984 is positioned over the second drain entry portion 912 with the flange 980 overlappingly captured by the lip 986 . The fasteners 956 are screwed or otherwise secured into bores formed in the base 908 to retain the bracket 984 on the base. Alternatively, a gasket 988 may be interposed between the base 908 and the bracket 984 to provide sealing.
[0059] While the fasteners 956 may directly threadably engage the material of the base 908 , other types of fasteners are contemplated. For example, as shown in FIG. 14 , the base 1008 is modified to receive an undercut anchor-type fastener 1056 . The fastener 1056 includes a receiving part that resides embedded within the material of the base 1008 and a bolt that threads into the receiving part. The fastener 1056 holds gasket 988 and bracket 1084 in a similar fashion as the fastener shown in FIG. 13 . The illustrated fastener 1056 is a commercially anchor available from Keil®. Preparation of the base 1008 for fastener 1056 is a well-known process.
[0060] Another type of fastener is shown in FIG. 15 . In this embodiment, the base 1108 may be provided with straight sided bores to receive a press-in threaded anchor 1190 that receives a bolt and nut fastener 1156 . This type of anchor/fastener is commercially available from specialinsert® and holds bracket 1184 in a similar fashion as the fastener shown in FIGS. 13 and 14 .
[0061] Turning to FIG. 16 , the first drain end portion 1211 is shown formed with an externally threaded extension 1292 that extends downwardly from the base 1208 . The second drain entry portion 1212 includes a first end portion 1222 with internal threads that are shaped and sized to threadably engage the externally threaded extension 1292 . A second end portion 1224 is configured as in previous embodiments. Installation of the second drain entry portion 1212 proceeds by threading the first end portion 1222 of the second drain entry portion onto the externally threaded extension 1292 until the flange 1280 abuts the bottom of the base 1208 .
[0062] FIG. 17 shows a sink base 1308 with a first drain entry portion 1311 and a second drain entry portion 1312 . The second drain entry portion 1312 includes a first end portion 1322 with a radially extending flange 1380 and a second end portion 1324 opposite the first end portion. The flange 1380 is embedded in the material of the first drain entry portion 1311 of the base 1308 . The embedding may occur during manufacture of the sink base. For example, the flange 1380 may be inserted into a mold or fixture used to case the sink base prior to casting such that the cast material may flow around portions of the flange 1308 .
[0063] FIG. 18 shows yet another fastener 1456 comprising a flange nut 1490 and mounting screw 1456 . The flange nut 1490 is cast or embedded into the material of the base 1408 and resides within the material permanently as a result of its shape. The second drain entry portion 1412 is held in position on the underneath surface of the base 1408 by the interconnection of the flange 1480 of the first end portion 1422 and the lip 1486 located on the bracket 1484 . The mounting screw 1456 holds the bracket 1484 to the underneath of the base 1408 with an optional gasket 1488 interposed between the bracket and base.
[0064] FIGS. 19-20 show yet another mechanism and method of connecting a second drain entry portion 1512 via a first end portion 1522 to a sink basin 1508 . The sink basin 1508 includes a first drain entry portion 1511 defining an opening 1510 provided with three or more spaced blocks 1581 surrounding the opening. The spaced blocks 1581 are formed with radially inwardly facing notches 1583 . The spaced blocks 1581 may be formed as a unitary, one-piece construction with the sink or attached to the sink basin 1508 with an adhesive, for example. The notches 1583 may be provided via other features formed in or attached to the basin 1508 .
[0065] A locking bracket or lockring 1585 is shaped and sized to interconnect and lock to the spaced blocks 1581 in a first rotational orientation and disengage from the spaced blocks in a second rotational orientation. The locking function is accomplished by engaging a plurality of spaced lugs 1591 that extend radially outwardly from the bracket 1585 . The lugs 1591 are configured to engage with the notches 1583 in the first rotational orientation. The bracket 1585 may be a substantially flat lock ring and includes a lip 1586 shaped and sized to retain the first end portion 1522 .
[0066] The bracket 1585 includes cutaways 1589 between the lugs 1591 . When the cutaways 1589 are aligned with the blocks 1581 , no engagement occurs between the bracket 1585 and the blocks and second drain entry portion 1512 can be disassembled from the sink. The bracket 1585 may also include stops 1587 that are formed between the lugs 1591 and the cutaways 1589 , which may be angled with respect to the plane of the bracket 1585 and contact the blocks to stop the rotation of the bracket. When the stops 1587 contact the blocks 1581 and rotation of the bracket 1585 is thereby arrested, the installer can be assured that the lugs 1591 are properly and fully engaged in the notches 1583 and the second drain entry portion 1512 is secured to the basin 1508 .
[0067] During assembly, the first end portion 1522 of the second drain entry portion 1512 is positioned against the underneath of the basin 1508 surrounding the opening 1510 . The bracket 1585 is installed over the second drain entry portion 1512 with the cutaways 1589 aligned to clear and pass over the blocks 1581 . The lip 1586 overlaps and captures the flange (not shown) of the second drain entry portion 1512 . The bracket 1585 is rotated ( FIG. 19 ) so the lugs 1591 are inserted and engage with the notches 1583 into the second rotational orientation shown in FIG. 19 . The stops 1587 contact the blocks 1581 to arrest the rotation of the bracket 1585 and provide confirmation that the lugs 1591 are fully engaged, which can occur without the need for visual inspection. Reversing the rotation of the bracket 1585 reverses the installation process and permits disassembly of the drain from the sink.
[0068] FIG. 21 shows another embodiment of a mechanism and method for attaching a drain to a sink. The sink basin 1608 includes an opening 1610 defined by a first drain entry portion 1611 . A second drain entry portion 1612 is brought into contact with the underneath the drain basin 1608 by contacting a flange 1680 of a first end portion 1622 of the second drain entry portion to the underneath of the drain basin. A bracket 1684 , which is sized and shaped to hold the flange 1680 via a lip 1686 and abut the underneath of the drain basin 1608 . An adhesive 1693 is applied to the side of the bracket 1684 in contact with the drain basin 1608 , which functions to hold the bracket on the drain basin.
[0069] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
[0070] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
[0071] Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
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Sinks and drains for sinks permitting the attachment of the drain to the sink such that the drain is substantially disposed below the top surface of the sink basin, and such that there is no discernable separation between the base of the sink basin and the drain when viewed from above the sink. A method of making a sink such that there is no discernable separation between the base of the sink basin and the drain when viewed from above the sink.
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FIELD OF THE INVENTION
This invention relates to the field of directional surveying instruments or to instruments used in determining the path which is established by a deep well and is particularly directed toward that type which depends upon an electrically driven gyrocompass as one of the instruments incorporated therewith.
When deep holes are drilled into the earth's surface, the path taken by the drill bit is rarely a straight line. This may occur because of variations in the structure being penetrated or simply because of limitations in the equipment or techniques being used. In the case of oil wells, the direction of the hole may, for many reasons, be deliberately changed from vertical. In any event, it is rare that either the bottom or indeed the greater portion of the hole lies directly beneath the wellhead.
It is particularly important in oil wells to determine carefully not only the location of the bottom and/or a particular portion of the hole (this would obviously be important from a legal standpoint) but also the entire path the drill bit takes as the well progresses. This kind of information would be vital in the event of a blowout of the well if, as a means of controlling the blowout, it became necessary to drill a relief well to the immediate vicinity of some point in the existing well.
To determine the path of the hole, there are two systems in general use today, both of which are included in what has come to be known as "directional surveying."
In the first, a magnetic compass in conjunction with an inclinometer comprises the instrumentation. The equipment is arranged so that it may be lowered into the bore hole to the desired depth at which point the inclination and the direction of the inclination are measured. Acquisition of this data is usually by means of a photograph of the compass and inclinometer taken by a camera incorporated into the instrument package. If these readings are taken at appropriate depth intervals (on the order of 100 feet or so), the path taken by the drill bit can be extrapolated by mathematical means.
In the second system, the magnetic compass is replaced by an electrically driven gyrocompass. Survey and calculating procedures are essentially the same as described above. The use of the gyrocompass does, however, permit directional surveys to be made where various disturbances of the earth's magnetic field render the magnetic compass useless.
It should be obvious from the above that the instruments described must be contained in some sort of protective enclosure capable of resisting whatever chemical, pressure, or temperature factors may be present and yet compromising in no way their proper functioning.
DESCRIPTION OF THE PRIOR ART
Heretofore, electrically driven gyrocompass directional surveying instruments have been limited for use in those wells which are not considered deep wells by today's standards. Therefore, the industry has by necessity been totally dependent upon the use of the magnetic compass directional surveying instruments when surveying deep wells. In view of the above, it is deemed prudent to discuss, at length, certain characteristics of the prior art.
Accordingly, the instrument package and protective enclosure generally in use for previous gyrocompasses is shown in FIG. 1 of the drawings. A gyrocompass 501 has fitted on its lower end an electrical connector and an index pin arranged so that it is connected both mechanically and electrically to a switch sub 502. The switch sub 502, on its upper face, has the configuration and construction necessary to interface properly with the gyrocompass 501.
The switch sub 502 and its lower end are suitably arranged so that an electrical current from a gyro battery pack 503 may be fed through it to the gyrocompass 501, i.e., for powering the spin motor.
The switch sub 502 also has in it a precisely located transverse tapered hole, as at 504, and on its outer surface a groove, as at 505, of particular cross-section. The purpose for both of these features will be explained later.
To complete the lower portion of the package an outer protective tubular enclosure, as at 506, is incorporated. The ends of this enclosure contain female threads and a packing means to prevent entry of fluids. The lower end of the switch sub 502 and the upper end of a bottom sub, as at 507, incorporate the necessary thread and gland configuration to interface with the lower enclosure 506.
The upper section of the package includes the gyrocompass 501; and inclinometer, as at 508; a camera, as at 509; and the camera power source or battery pack, as at 510. The camera battery pack 510 supplies power to the camera 509 both for illumination and for film advance purposes. The inclinometer 508 is of tubular configuration and is transparent at both ends so that the camera can simultaneously photograph both the angle sensing device and the gyrocompass card, i.e., the card is not shown but is fitted to the upper end of the gyrocompass 501 in a manner well known to those skilled in the art.
The package also includes an upper protective enclosure, as at 511, and a top sub member 512 which are arranged similar to their counterparts 506 and 507 on the lower section and function in like fashion.
Referring now to FIG. 1, particularly the tapered hole 504 and the groove 505 which are used in the following fashion:
In preparing the instrument package for lowering into a borehole B (see FIG. 2) it is necessary to calibrate accurately the gyrocompass 501 and other portions of the equipment. To help accomplish this task, a tripod stand, as at 513, is used to support the package 514 directly over the well head as shown in FIG. 2 of the drawings. An upper plate 515 of the stand 513 is shown in isometric view in FIG. 4 of the drawings. This plate 515 incorporates a chamferred center hole, as at 516, surrounded by a protractor scale 517. This plate 515 also has machined into it a slot, as at 518, which allows (see FIG. 1) a grooved portion 505 of the switch sub 502 to engage the plate 515 in such a manner as to establish the center line of the instrument package 514 coaxial with that of the top plate 515 with considerable accuracy. This arrangement also allows the instrument package 514 to be moved rotatably through angles which can be measured with great accuracy by observing the position of the switch sub 502 relative to the protractor scale 517 by means of suitable index marks located on the switch sub 502.
The other device necessary to the calibration of the gyrocompass is a telescope type transit instrument, as at 519, and as shown in FIG. 6 of the drawings. The transit 519 is mounted on a pin as at 520, which has a tapered portion, as at 521, on one end thereof. This tapered portion 521 is arranged to matingly fit into the tapered hole 504 in the switch sub 502. With this arrangement, it can be seen that by sighting a known land surveyor's benchmark with the transit 519, directions necessary to the calibration of the gyrocompass 501 can be established with requisite accuracy.
Further details regarding calibration procedures would add little to the background necessary for the disclosure of the invention except for the manner in which access is obtained during such procedures. This will be outlined in the following paragraph and is germane to the disclosure.
The usual procedure used in setting the gyrocompass surveying equipment would be more or less as follows:
Referring to FIG. 3 of the drawings, the gyro battery pack together with its protective enclosure (shown together and as characterized by the numeral 522) would be assembled to the switch sub 502 and this assembly placed in the tripod stand 513 over the well head or bore B. The gyrocompass 501 would be placed in position and the gyrocompass calibration described earlier would then be carried out.
Referring now to FIG. 5 of the drawings, it will be seen that added now to the above components are the inclinometer 508, the camera 509, and the battery pack 510. Shown also but not in assembled position is the upper protective enclosure 511 and the top sub 512 both of which are now suspended from a cable and winch assembly which are not shown. However, it should be noted that the cable and its associated winch mechanism are used to elevate the upper enclosure to a point above the instrument such that it may then be lowered, if desired. Thus, access to the gyrocompass is still possible and any final adjustments may be carried out.
After all adjustments and calibrations have been accomplished, the upper enclosure is lowered so that it may be lowered to the switch sub 502 by means of the threaded connection described earlier. The assembly is now elevated slightly, the stand 513 may be removed and the complete instrument package may then be lowered into the borehole B and the survey commenced.
The overall length of a typical package of this nature would be 12 to 14 feet. It can be seen that transporting this complete assembly to and from the well location by automobile, light truck or as is required on offshore locations, by aircraft, could be somewhat awkward. The usual procedure, then, is to separate the package at the switch sub 502 and, using suitable protective plugs and closures, transport the equipment into approximately equal size pieces.
In the design of instrument packages for gyrocompass type directional surveying equipment, aside from internal considerations having strictly to do with functioning of the instrument components, one is operating under three primary constraints: size, pressure and temperature. A brief discussion of each follows:
Size--Mentioned earlier was the problem of manageable lengths for transport purposes. Aside from this, length considerations allow considerable latitude in design and represent no serious problems. Not so with diameters. With this equipment, as with most other that is to be run in an oil well borehole, the smaller the better. The tubular members into which this equipment must fit can be quite small. This is particularly true as the drilling progresses to greater and greater depths. As a general rule, the deeper the hole, the smaller its diameter. This infers that the drill pipe used to turn the drill bit will also become smaller and smaller. Couple this with the fact that this equipment often runs inside the drill pipe and the magnitude of the problem becomes apparent. Some wells require instrument packages of 2 inch maximum diameter. Other wells can tolerate somewhat larger diameters but it would be fair to say that any package whose diameter exceeded 31/2 inches (88.9 millimeters) would be of little use.
Pressure--Oil wells, during the drilling process, are filled with a fluid known as "drilling mud." This name is misleading inasmuch as this fluid is compounded in a scientific manner to rather exact specifications. Drilling mud has many functions but the one which concerns us is its use as a means of offsetting formation pressures. The specific gravity of the drilling mud can be changed by the addition of various materials. The hydrostatic head then developed by the mud can be such that the formation pressure is exactly balanced. This state of equilibrium is necessary to prevent loss of control or "blowout." While this technique works very vell, it means that the instrument package must be capable of withstanding substantial pressures without collapse or even the slightest leak.
Temperature--As the earth's surface is penetrated deeper and deeper, albeit by a small amount, the bottom of the hole comes closer and closer to the earth's core. This core is believed to consist of molten iron at extremely high temperatures. This is confirmed by the fact that the bottom hole temperature of deep holes increases above surface temperature by a factor as for example 17° F. per 1,000 feet depth (9.45° C. per 304.8 meters). One could therefore expect to encounter temperatures in the neighborhood of 250° F. at 10,000 feet (121.1° C. at 3,048 meters), 330° F. at 15,000 feet (176° C. at 4,572 meters) and 420° F. at 20,000 feet (215.56° C. at 6,096 meters) for example. The operating depth of the instrument package would therefore be limited by its ability to withstand the temperature encountered at that depth.
With the foregoing size, pressure and temperature constraints in mind, it would be of some interest in completing this discussion of the present state of the art regarding directional surveying to determine the safe operating depth for an instrument package designed more or less along the lines of the one used in the example.
Size Constraint--The diameter of the largest component in the subject system would be the gyrocompass 501. These devices are available in diameters as small as 11/2 inches (38.1 millimeters). Accordingly, then, the outside diameter of the package need only be enough larger than 11/2 inches (38.1 millimeters) to provide a wall thickness sufficient to withstand the given pressure.
Pressure Constraint--If a 2 inch (50.8 millimeters) outside diameter is an acceptable size, then by using a 11/2 inch (38.1 millimeter) diameter gyrocompass 501 and allowing some clearance between the gyrocompass 501 and the outer enclosure, a wall thickness of as much as 0.218 inches (5.54 millimeters) would be possible. Using a material with a compressive strength of 100,000 pounds per square inch or 6,802.7 atmospheres of pressure, which material is readily available, and performing the necessary calculations, we find that such an enclosure would have a collapse pressure of about 19,500 pounds per square inch or 1,326.5 atmospheres of pressure. Depending on the specific gravity of the drilling mud in use at the time, this would mean a maximum operating depth for this package of between 15,000 feet to over 25,000 feet (4,572.0 meters to 7,620.0 meters). All of this presupposes glands and seals with commensurate pressure capabilities.
At this point it can be observed that neither size nor pressure represent any insurmountable obstacles to operating depths in the 20,000 plus foot range (6,096 meters). Unfortunately, the same cannot be said for temperature, as will be shown below.
Temperature Constraint--The temperature limitation on most commonly available electrical and electronic components as well as the camera film is 125° C. maximum. This translates to about 260° F. Applying the 17° F. per thousand feet (9.45° C. per 304.8 meters) criterion mentioned earlier and assuming a surface temperature of 70° F. (21.1° C.), we find that the temperature limit imposed by film and electrical components will be reached at 11,000 to 12,000 feet (3,352.8 meters to 3,657.6 meters). This limitation can be mitigated somewhat by operating procedures that do not allow the instrument package to remain beyond this "thermal barrier" for lengths of time longer than that required to heat the package beyond component temperature limits. It can nevertheless be said that the depth limitation on this equipment is imposed by temperature considerations.
The foregoing is a fair representation of the present state of the art as known by the applicant in regard to the present capabilities of directional surveying equipment of the gyrocompass type. Moreover, as far as is known by the applicant, there are at present no gyrocompass type directional survey instruments in commercial use that have a high pressure/temperature capability. There are, however, many magnetic compass systems that--by insulating the instrument in a vacuum flask or Dewar flask and in turn encapsulating the flask in a pressure vessel--achieve a temperature/pressure resistance capability that will allow operation in much deeper and/or hotter holes than can be done with gyrocompass or uninsulated systems.
A typical flask of this type is shown in FIG. 7 of the drawings and consists of the following: an outer tube, as at 524; and an inner tube, as at 525; are welded to a neck fitting, as at 526. The inner tube 525 has its opposite end closed. The outer tube 524 has its opposite end closed except for an evacuation fitting, as at 527. After assembly, a vacuum pump is connected to the fitting 527, and the volume contained between the tubes is evacuated to a pressure of 10 -4 torr or less. At this pressure virtually all heat transfer across the space between the tubes ceases. Radiation heat transfer is reduced by either making the outer surface of the tubes reflective or by placing layers of reflective foil in the evacuated space. To complete the assembly, the flask is fitted with a plug, as at 528, which is fabricated from a metal in which case it functions as a heat sink or from a low heat conductivity material such as plastic, in which case it functions as an insulator. On occasion, the plug will consist of a combination of the two. The plug is usually fitted with an O-ring, as at 529, or similar seals to prevent air entry.
These flasks vary somewhat in their construction, but this is understandable, since their designs are usually proprietary in nature. They all, nevertheless, use as their primary insulating method the evacuated Dewar flask. Although the vacuum flask has been successfully applied to magnetic units, some problems arise when the application thereof to gyrocompass is considered. If one used a single flask to encapsulate the gyrocompass instruments, this flask would have to be much too long to be easily transported. Furthermore it would be difficult, if not impossible, to develop procedures whereby the gyrocompass and other components could be assembled for calibration in the tripod stand and then removed from the stand, placed in the flask and the flask in turn placed in the outer pressure vessel. These problems do not occur in the magnetic units because they do not require extensive calibration, nor are they nearly so long as the gyro units.
In addition to the above, applicant is aware of many U.S. patents pertaining to these type instruments. See, for example, U.S. Pat. No. 1,924,816, granted to Sperry in 1933. In addition, see U.S. Pat. No. 2,187,028, granted to Hendrickson in 1940; U.S. Pat. No. 3,079,696 granted to Van Rooyen in 1963; U.S. Pat. No. 3,753,296 granted to Van Steenwyk in 1973; and U.S. Pat. No. 3,896,412 granted to Rohr in 1975. It will be appreciated by those skilled in the art that neither the state of the art as known by the applicant and fairly well outlined above or any of the above patents suggest or disclose applicant's concept.
SUMMARY OF THE INVENTION
This invention is directed towards overcoming the limitations or disadvantages and problems associated with previous gyroscopic directional instrument systems, particularly the problems having to do with the depth to which devices of this nature heretofore have been restricted. The objectives of the present invention are as follows:
First, to provide a pressure resistance capability of 24,000 pounds per square inch (1,632.7 atmospheres of pressure) which permits operation to depths of 25,000 feet (7,620 meters); if drilling weight is less than 18 pounds per gallon (2.14 kilograms per liter); and 21,000 feet (6,400.8 meters) if less than 22 pounds per gallon (2.62 kilograms per liter).
Second, to provide a temperature resistance capability such that operation for periods of up to 6 hours in wells with bottom hole temperatures of 450° F. (232.2° C.) are possible without damage to either the camera film or any instrument component.
Third, to provide a package having a maximum outside diameter of 3 inches (76.2 millimeters).
Fourth, to provide an interarrangement of pressure vessel and vacuum flask such that transport lengths may be practical for normally encountered transport methods.
Fifth, to provide an interarrangement of pressure vessel and vacuum flask such that calibration and set up procedures vary as little as possible from those presently used for the prior gyrocompass system.
Sixth, to provide an interarrangement of components disposed within the flasks to preclude, insofar as practicable, any untoward structural demands on the vacuum flasks with the object being that of precluding the development of any vacuum leaks, i.e., these vacuum flasks are notorious for their fragility.
Seventh, to provide improved rigidity and alignment of instrument components within the package.
The manner in which each of these objectives has been met will be described below.
Generally speaking, the apparatus of the present invention is intended to be used for the directional surveying of deep wells, i.e., 20,000-25,000 feet range or 6,096 meters to 7,620 meters, and which is specifically identified as a gyroscopic directional survey instrument having a high pressure and a high temperature capability, e.g., 24,000 pounds per square inch, or 1,632.65 atmospheres and 450° F. or 232.22° C. While in its fully assembled configuration, the apparatus may be described as being exceptionally long (or at times unwieldy), e.g., 12 to 16 feet long, or 3.66 meters to 4.88 meters, it is quite remarkable that it does not exceed 3 inches, or 76.2 millimeters in diameter. Therefore, it may readily be lowered into the small diameter steel casings normally defining the walls of these deep wells. In view of its cumbersomeness, it is significant to note that the apparatus may readily be broken down into upper and lower sub assemblies when being transported to or from the well site. Moreover, structure is included for individually protecting each sub assembly from the adverse affects of the extreme pressure and temperature. Therewith, the feasibility of "on site" mating and demating of the sub assemblies is achieved. Equally significant is that structure is included which readily enables the required physical access--at the "on site" location--to the internally disposed gyrocompass, inclinometer, and camera systems, i.e., for the purpose of accomplishing the initial preparations and/or calibration procedures as generally outlined previously.
Pressure Resistance Capability--In order to meet the 24,000 pounds per square inch requirement or 1,632.65 atmospheres, it was necessary to choose a material and wall thickness that would fall within the 3 inch or 76.2 millimeter outside diameter limit. Type 416 stainless steel heat treated has a yield strength for this purpose. Using calculation methods available in any good mechanics of materials text the wall thickness was readily determined to be a nominal 0.344 inches, or 8.74 millimeters. This yields an inside diameter of 2.312 inches or 58.73 millimeters, and with a 11/2 inch or 38.1 millimeter diameter gyrocompass, an annulus of 0.406 inches or 10.31 millimeters, more than enough for the vacuum flask. These dimensions were used on the upper section of the package. On the lower section, the maximum component diameter was 1.032 inches, or 26.21 millimeters (the batteries). Therefore, a smaller outside diameter was chosen. Using the above methods and an outside diameter of 2.250 inches, or 57.15 millimeters, a wall thickness of 0.281 inches, or 7.14 millimeters and an annulus of 0.328 inches, or 8.33 millimeters, was readily obtained, here again more than enough for the vacuum flask.
With regard to the points where the tubular pressure vessels interface with the top, bottom or switch subs, the sealing method used is that of conventional rubber O-rings. The design methods are readily available from either machine design text or O-ring manufacturer's literature.
Temperature Resistance Capability--The primary insulating means used in the present device is the vacuum flask or Dewar flask discussed earlier. In addition to the capability of these flasks to resist heat transfer from outside, a metallic heat sink is included in the flask enclosing the gyrocompass. This heat sink serves to mitigate internal temperatures by absorbing heat evolved by the spin motor of the gyrocompass. Without the heat sink, this heat would be available to raise the temperatures of components at a much higher rate.
The application of the vacuum flask to the lower section of the device is, except for the absence of the heat sink, similar to the upper section which will be discussed in detail later in the specification.
Outside Diameter Requirement--The discussion on pressure capabilities showed that the 3 inch or 76.2 millimeter maximum criterion was observed in the design of the device.
Transport Length Requirement--It was determined that the only way in which the apparatus could be made to disassemble into reasonable length components was to insulate the upper and lower sections independently with separate vacuum flasks. This allowed the unit to be "broken" at the switch sub into two parts of manageable lengths. The drawback to this approach is that it allows portions of the switch sub to come into direct contact with the drilling mud. This drilling mud, being at bore hole temperature, conducts heat directly into the switch sub and, if nothing is done, the switch sub then conducts heat into instrument and equipment spaces. The use, however, of an insulator plug described herein has proved (in actual tests) to be adequate to prevent this happening to any significant degree.
Set Up And Calibration Requirement--Reference is made to the discussion of setup and calibration procedures at the beginning of this disclosure and in particular to the stage where the upper pressure vessel is lowered by cable down over the instruments and then coupled to the switch sub. It was felt that in adding the vacuum flask to the system that it must be done in such a manner that the flask need not be handled as a separate piece. Aside from saving the labor required for handling the additional piece, this approach avoids the risk of damage to the flask in handling. In short, if the flask is mechanically integrated into the upper pressure vessel, handling procedures at the well will remain virtually unchanged. The manner in which this is accomplished will be discussed in detail later in the specification. Nevertheless, for maintenance purposes, the flask can easily and quickly be removed by removing the top sub 512 and sliding the flask out.
Vacuum Flask Installation Requirement--The manner in which this requirement for minimum structural loads on the vacuum flask for the upper portion of the apparatus was described above. The lower portion, about which little has been said, has an entirely different set of circumstances surrounding its operation. The lower portion consists in the main of the battery pack used to drive the gyroscope spin motor. The voltage requirement for this motor is 28 volts DC. To insure adequate voltage for the motor, the battery pack is sized so as to supply excess voltage initially, this higher voltage being reduced electronically through a typical voltage regulator system to the requisite 28 volts. Therefore, as the batteries are being drained during the service, their output voltage drops, and when the 28 volt level is reached they are considered spent. Experience has shown that by using "C" or "D" size alkaline type cells, voltage in excess of 28 volts can be maintained sufficiently long for survey purposes if the initial voltage is 40-45 volts. For the subject apparatus a pack consisting of 28 individual "C" cells of 1.5 initial volts each was preferred and has proven to be more than adequate. In order to meet the pressure/size requirement of the outer vessel, it was decided that these cells should be arranged in a single vertical string.
Arranging batteries in a single string must be done with a degree of caution because of the following:
In lowering the device into the bore hole it is quite often subjected to sizable inertia forces caused by either the cable, i.e., due to an abrupt stop of the winch drum, or simply by virtue of the package striking the bottom of the hole. Random forces are also caused as the package strikes the side of the casing or bore hole.
Manifestation of these forces has been observed in the form of indentation or diaphragming of the ends of the cells. Even a small amount of permanent or temporary deformation, while having no apparent effect on cell operation, can cause the net length of the string to change by significant amounts. For instance, a 1/64 inch or approximately 0.4 millimeters deformation per cell will reduce the string length by 7/16 inches or slightly more than 11 millimeters. Any electrical contact used to tap the energy of the battery string must be spring loaded in order to absorb this length change and yet maintain electrical continuity.
Attempts to mitigate inertia effects have taken the form of a large contact spring disposed at the lower end of the string of batteries to act in storing energy which can then be dissipated by harmless oscillations. Unfortunately, this lower spring travel imposes an even greater length variance requirement on the upper spring loaded contact and the upper contact must therefore be designed with this in mind.
The inertia loads, it is felt, are sufficiently large that it would be unwise to impose them in any way on the vacuum flask.
Inertia loads on the vacuum flask are minimized in that when the batteries move downward relative to the apparatus, i.e., because of inertia forces, a portion of the energy present will be stored by a load bearing compression spring. The remaining energy is converted in a manner to be fully disclosed in the specification. Albeit, this arrangement insures that none of the inertia forces will be imposed on the inner wall of the vacuum flask.
Rigidity and Alignment Requirement--Early in this disclosure a description of the arrangement of the instrument components was given and it showed how the gyrocompass, inclinometer, camera and camera battery pack were stacked one on top of the other. Because of their delicate nature, coupling these components together results in connections that are weak, at best, and subject to misalignment or damage if moment loads are imposed on them.
Accordingly, the concept herein disclosed includes structure for establishing a rigid protective light weight casing that may readily be manually placed in its position for circummuring the inclinometer, the camera, and at least a portion of the gyroscopic directional instrument system. Whereby, the likelihood of these instruments sustaining physical damage as a result of accomplishing the mating and unmating steps at the well site is minimized if not precluded. The manner in which this is accomplished will be fully disclosed later in the specification.
A device constructed in accordance with the concept herein disclosed has been built and operated within a 22,000 foot or 6,705.6 meter oil well using 16.6 pounds per gallon or 1.97 kilograms per liter drilling mud and having a bottom hole temperature of 420° F. or 215.6° C. was successfully surveyed just recently. To the best of applicant's knowledge, a well of this temperature and depth has never been surveyed before by using a gyrocompass type directional surveying instrument package.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-7 depict various arrangements of the prior art.
FIG. 8 is side-elevational view drawn substantially to scale of the complete instrument package or gyroscopic directional surveying instrument 11 of the present invention.
FIGS. 9-11 are enlarged fragmentational sectional views taken along the vertical center line of the instrument shown in FIG. 8 with FIG. 9 being the uppermost portion thereof, FIG. 10 being the medial portion thereof and FIG. 11 being the lower portion thereof.
FIGS. 12 and 13 jointly depict structure shown in FIG. 10; however, certain structure has been deleted for clarity.
FIGS. 14 and 15 jointly depict enlarged structure shown in FIG. 11; however, certain structure has been deleted for clarity.
FIG. 16 is a sectional view taken as on the line XVI--XVI of FIG. 9 of the drawings.
FIGS. 17-18 are intended to depict the manner in which the apparatus may be readily broken down into upper and lower sub assemblies, with FIG. 19 showing an internally threaded protective cap adapted to threadedly engage the upper sub assembly (FIG. 17), and FIG. 20 depicting an externally threaded protective plug adapted to threadedly engage the lower sub assembly (FIG. 18).
DESCRIPTION OF THE PREFERRED EMBODIMENT
The heart of the invention resides in the techniques or concepts employed for enclosing and the packaging of the various instruments in general and to the gyrocompass system in particular that is the principal instrument employed with this type system. Therefore, since it is believed that the overall system is new, it is deemed appropriate to direct this disclosure toward the entire system.
The improved gyroscopic directional survey instrument 11 of the present invention is shown substantially to 1/16 scale in FIG. 8 of the drawings. It will be appreciated by those skilled in the art that certain conventional features disclosed herein will be shown in diagrammatic drawing symbols since their detailed illustration is not essential for the proper disclosure of the invention. For example, referring to FIG. 9 of the drawing it will be seen that the gyroscopic directional surveying instrument or apparatus 11 includes a gyrocompass 13 having an electric motor 15 for suitably driving a gimbal arrangement 17, a typical inclinometer 19, and a typical camera 21 having a suitable camera battery pack 23. These various above mentioned instruments are disposed one on top of another substantially in the order depicted in FIG. 9. The manner in which they are made to interface one with the other is deemed to be a typical arrangement.
The apparatus 11 includes isolation means generally indicated at 25 in FIG. 8 of the drawings for maintaining, at least for a reasonable period of time, a suitable internal environment in which the gyroscopic directional instrument 13 may reliably function while being exposed exteriorly to an extremely hostile environment known to exist at the lower reaches of deep wells which extend several miles into the surface of the earth, like that previously described and as shown in FIGS. 2, 3, and 5 of the drawings. In other words, the isolation means 25 is intended to encompass the entire enclosure and packaging of the above mentioned instruments in general and the gyrocompass 13 in particular, as well as certain ancilliary equipment yet to be mentioned.
The isolation means 25 comprises heat shield means generally indicated at 27 in FIGS. 9-11 of the drawings, for protecting the gyroscopic instrument system (yet to be described in its entirety) from the extremely hot temperatures inherently existing in the hostile environment. The isolation means 25 also includes interface switch sub means, as at 29, for enabling the apparatus 11 to readily be broken down into upper and lower sub assemblies, as at 31, 33 to facilitate transporting the apparatus 11 between a laboratory-like environment and a well field environment in a manner to be fully disclosed as the specification proceeds.
The heat shield means 27 alluded to above includes an upper Dewar vacuum flask, as at 35, constituting a part of the upper sub assembly 31 for encompassing and heat shielding a first group of component members of the apparatus 11 and which are characterized generally by the numeral 37 in FIG. 9 of the drawings. The heat shield means 27 also includes a lower Dewar vacuum flask, as at 39 in FIG. 11 of the drawings, and which constitutes a part of the lower sub assembly 33 for encompassing and heat shielding a second group of component members of the apparatus 11. The second group of component members are characterized generally therein by the numeral 41. Thus, each of the sub assemblies 31, 33 is independently shielded from the extremely hot temperatures.
The gyroscopic directional instrument system alluded to above includes the previously mentioned electric motor means 15 for driving the gimbal arrangement 17 and a first power supply, characterized by the numeral 43 in FIG. 11 of the drawings, for providing a principal source of electromotive force (EMF) for powering the electric motor means 15.
The isolation means 25 alluded to above includes heat sink means, generally indicated by the numeral 45 in FIGS. 9 and 10 of the drawings, for absorbing, within limits, the heat being generated by the electric motor means 15 as power from the first power supply 43 is being dissipated in the process of maintaining optimum revolutions-per-minute (RPM) of the gimbal arrangement 17.
The heat sink means 45 alluded to above includes a first mass of metal, as at 47 in FIG. 10 of the drawings, which is preferably formed from brass or the like and is disposed adjacent to the electric motor means 15. The heat sink means 45 also includes a second mass of metal, preferably formed from aluminum or the like, and shaped so as to be disposed adjacent the first mass of metal 47 and the electric motor means 15 for readily conducting heat from one to the other.
Moreover, the second mass of metal 49 preferably is tubular shaped wherein a first portion thereof, as at 51 in FIG. 10 of the drawings, is circumposed about at least a portion of the first mass of metal 47 while a second portion thereof, as at 53 in FIG. 9 of the drawings, is circumposed about the electric motor means 15.
In addition, a third portion of the second mass of metal or tubular heat sink means 49 is characterized in FIG. 9 of the drawings by the numeral 55 and is circumposed about the inclinometer means 19.
Further, the tubular shaped sink means 49 includes a fourth portion, as at 57, which is circumposed about the camera means 21.
It will be appreciated by those skilled in the art that the principles of the Dewar flask are well known. Therefore, no attempt will herein be made to describe the details of the Dewar flask. Indeed, it should be sufficient to simply state that the upper vacuum flask 35 includes an inner wall, as at 59, and an outer wall, as at 61, jointly defining an evacuated chamber, as at 63. Likewise, and referring to FIGS. 11, 14 and 15 of the drawings, it may be seen that the lower vacuum flask 39 includes an inner wall, as at 65, an outer wall, as at 67, jointly defining an evacuated chamber as at 69.
The lower vacuum flask 39 primarily is employed for the purpose of shielding the first power supply 43 from the extreme temperatures. The first power supply 43 preferably is comprised of a plurality of single cell battery members 71 which may individually be characterized by the numerals 71 1 , 71 2 , 71 3 , etc. Indeed, the first power supply 43 preferably includes numerous individually cased battery cell members 71 arranged in series in like manner as a typical flashlight, thus establishing a long string of battery cell members 71 having considerable weight. For example, the first power supply 43 may include 28 such batteries 71 which preferably are well known "C" cells of 1.5 initial volts each, thus providing an initial voltage of 40 to 45 volts.
The gyroscopic directional instrument system includes voltage regulator means, as at 73, which is interposed between the first power supply 43 and the electric motor means 15 for regulating the voltage output, i.e., 40 to 45 volts of the first power supply 43. Thus, the voltage being applied to the electric motor means 15 remains within certain acceptable limits, e.g., 28 volts or the like, even though the voltage output of the first power supply 43 may vary exceedingly beyond the certain acceptable limits.
It should be understood that the camera battery pack 23 mentioned previously may optionally hereinafter be referred to as a second source of EMF. While the second source of EMF 23 will not be described in detail, it should be noted in FIG. 9 of the drawings that the second source of EMF 23 is smaller in diameter than are the other instruments 13, 19, 21. Therefore, from FIG. 9 of the drawings it may be seen that the second power supply 23 is surrounded by a toroidal shaped shock absorber or buffer, as at 75. The interior annular surface of the buffer 75 is compatibly shaped with the second power supply 23 so as to be a rather close fit. While the outer annular surface thereof preferably is compatibly sized with the exterior surfaces of the instruments 13, 19, 21. The buffer 75 preferably is formed from a substance having a degree of resiliency, e.g., polyethylene or the like, for the reasons which will be apparent as the specification proceeds.
Particular attention is now directed toward FIG. 10 of the drawings wherein it may be seen that the first and second masses of metal 47, 49 are compatible in size and shape to enable the first portion 51 of the tubular shaped heat sink means 49 to be slip fitted over the first mass of metal 47, i.e., so as to not only be contiguous therewith but to also provide a degree of rigidity to the tubular shaped heat sink means 49 for reasons yet to be disclosed.
The heat sink means 45 also includes quick disconnect fastener means, generally indicated at 77 for:
Firstly, rigidly joining the first and second masses of metal 47, 49 together and
Secondly, facilitating expediency in separating the first and second masses of metal 47, 49 one from the other.
From FIG. 12 of the drawings it may be seen that the first mass of metal 47 is provided with a reduced diameter portion, as at 81, and a larger diameter portion, as at 83, thus a shoulder, as at 85, is established.
Referring again to FIG. 10 of the drawings, it may be seen that the quick disconnect fastener means 77 includes spring loaded plunger means, as at 87, which is suitably attached to the first mass of metal 47 for coacting with an aperture, as at 89, provided in the tubular shaped mass of metal 49.
The plunger means 87 and the aperture 89 are interarranged to selectively enable the plunger means 87 to be made to register (close fittingly) with the aperture 89, when the tubular shaped mass of metal 49 is properly slip fitted over the first mass of metal 47. That is, the tubular shaped mass of metal 49 abuttingly engages the shoulder 35 (FIG. 12), thus precluding inadvertent separation of the first and second masses of metal 47, 49.
Stated another way, the tubular heat sink means 49 may also be described as means for establishing a rigid protective light weight casing that may readily be manually placed in its position for circummuring the inclinometer means 19, the camera means 21, and at least a portion of the gyroscopic directional instrument system, i.e., the gyrocompass 13 and the electric motor 15, whereby the likelihood of these instruments sustaining physical damage as a result of accomplishing certain mating and/or unmating steps is minimized if not precluded.
In addition, the close fit of the tubular heat sink means 49 with the shock absorber or buffer 75 prevents sidewise inertia effects from imposing moment loads on the instrument connection.
From FIG. 10 of the drawings it may be seen that at least a portion of the outer circumferential surface, as at 91, of the interface switch sub means 29 constitutes a medial portion of the outer surface of the apparatus 11 per se as shown in FIG. 8 of the drawings. Moreover, this results in the interface switch sub means 29 being directly exposed to the extremely hot temperatures. Therefore, the isolation means 25 alluded to includes heat insulation means, generally indicated by the numeral 93 in FIG. 10 of the drawings, for preventing any rise in temperature of the interface switch sub means 29 from adversely affecting certain components which may be housed within the upper and lower sub assemblies. The insulation means 93 preferably is formed from a substance selected for its heat insulation ability, e.g., Nema G-10 glass-epoxy and the like.
More specifically, the heat insulation means 93 includes switch sub heat insulation means, as at 95, for minimizing any heat transfer from the interface switch sub means 29 to certain components which may be housed within the upper sub assembly, i.e., the gyrocompass 13, etc. In addition, the heat insulation means 93 includes battery pack heat insulation means, as at 97 in FIGS. 10 and 11 of the drawings, for minimizing any heat transfer downwardly from the interface switch sub means 29 to the second group of components members 41, i.e., the first power supply 43. Thus, the temperature of the first and second groups of component members 37, 41 is not adversely affected by any rise in temperature of the interface switch sub means 29.
Particular attention is now directed towards FIG. 11 of the drawings wherein it may be seen where the apparatus 11 includes load transition means, as generally indicated by the numeral 99 therein, for precluding any inertia loads attributable to the weight of the long string of battery cell members 71 from acting adversely upon the lower vacuum flask 39.
More specifically, the load transition means 99 alluded to above includes providing battery tube means, as at 101, for containing the string of battery cell members 71, i.e., the battery tube means 101 is disposed within the lower vacuum flask 39. In addition, the load transition means 99 includes support means, as at 103, for supporting the battery tube means 101 merely from the upper end thereof. In this manner, the battery tube means 101 totally depends from the support means 103 and extends downwardly into the lower vacuum flask 39.
In addition, the load transition means 99 includes shock absorbor means, as at 105, which is disposed at the closed bottom, as at 107, of the battery tube means 101 with the lowermost one of the string of battery cell members, e.g., the battery 71 28 being restingly supported by the shock absorber means 105.
Particular attention is now directed towards FIGS. 14 and 15 of the drawings wherein it may be seen that the battery pack heat insulation means 97 forms a plug for the lower vacuum flask 39. Also, it may be seen that the battery tube means 101 alluded to above includes an intermediate tubular member, as at 109, interposed between upper and lower sleeve-like members 111, 113 respectively. Both of the sleeve-like members 111, 113 are provided with internally threaded portions, as at 115, 117 respectively. With the upper internally threaded sleeve-like member 111 constituting, at least in part, the support means 103 alluded to above.
The remote ends of the intermediate tubular member 109 are fixedly attached respectively to the upper and lower sleeve-like members 111, 113 in a manner to be described with the internally threaded portions 115, 117 thereof being outwardly directed.
The preferred manner of attaching the sleeve-like mmebers 111, 113 to the tubular member 109 is as follows: (Since both of the sleeve-like members 111, 113 are attached in exactly the same manner, the disclosure will be limited to only one of the sleeve members, i.e., the lower sleeve member 113.) The sleeve-like member 113, being of considerably heavier material than is the tubular member 109, is provided with an enlarged internal diameter portion, as at 119, thus establishing a shoulder, as at 121. The enlarged diameter portion 119 is compatibly sized so as to enable the tubular member 119 to be slip fitted internally thereof so as to abuttingly engage the shoulder 121. In addition, the enlarged diameter portion 119 is provided with a plurality of apertures, as at 123, which overlay the tubular member 109. The apertures 123 provide a suitable opening for receiving rosette welds, as at 125. Thus the sleeve-like member 113 is welded to the tubular member 109, i.e., the welds 125 do not protrude outwardly beyond the outer surface of the sleeve-like member 113.
The bottom 107 of the battery tube means 101 includes contact plug means 127 as best shown in FIG. 15 of the drawings, which is provided with an externally threaded portion, as at 129, for threadedly engaging the internally threaded portion 117, thus providing removable means for closing the bottom of the battery tube means 101.
The shock absorber means 105 alluded to above includes load-bearing compression spring means, as at 131 in FIG. 15 of the drawings, which is restingly supported upon the contact plug means 127. Thus, the weight of the long string of battery cell members 71 is initially carried by the load bearing compression spring means 131, thence by the contact plug means 127 (which depends from the lower sleeve-like member 113), thence longitudinally upwardly along the intermediate tubular member 109 where it is finally carried by the upper sleeve-like member 111, which constitutes, at least in part, the support means 103. It should be mentioned that the internally threaded portion 115 of the upper sleeve-like member 111 (FIG. 14) threadedly engages an externally threaded portion, as at 133, of the battery pack heat insulation means 97. In addition, since the battery pack heat insulation means 97 preferably is formed from glass epoxy, it, of course, is not only a heat insulator, as mentioned earlier, but is also an electrical insulator, the significance of which is about to be disclosed.
Both of the vacuum flasks, preferably being formed from stainless steel or the like, may readily be used, if desired, for conducting electricity. Therefore, the lower vacuum flask 39 is utilized for this purpose. In addition, the battery tube means 101 includes (at least in part) circuit means, generally indicated by the numeral 135 in FIGS. 10 and 11, for providing electrical continuity between the lowermost one of the string of battery cell members 71 and the lower vacuum flask 39. In this manner, the vacuum flask 39 may be utilized for providing, at least in part, an electrical circuit for interconnecting the electric motor means 15 and the first power supply 43.
Particular attention is again directed towards FIGS. 14 and 15 of the drawings wherein it may be seen that the circuit means 135 alluded to above includes a contact head member 137 preferably formed from brass or the like for engaging and thus establishing an electrical contact with the lowermost one of the batteries 71 28 . The contact plug means 127, preferably being formed from stainless steel or the like, includes inwardly and outwardly directed cup-like portions, as at 139, 141 respectively, communicated one with the other by an aperture, as at 143, provided therethrough. In addition, the load-bearing compression spring means 131 is disposed at least in part within the inwardly directed cup-like portion 139 and engages the contact head member 137 for making an electrical circuit between the contact head member and the contact plug means 127.
It should be understood that the vacuum flasks 35, 37 are notoriously fragile. Therefore, even though the lower vacuum flask 39 has a closed bottom, as at 145, it is incapable of assuming any of the inertia load which may be generated by the first power supply 43. Accordingly, even though the contact plug means 127 is disposed adjacent the fragile closed bottom 145, a definite spaced distance, as at 147, must be established between the bottom 145 of the lower flask 39 and the contact plug means 127.
The circuit means 135 alluded to also includes electrical conductor non-load-bearing compression spring means 151, which is disposed within the spaced distance 147 or at least in part within the outwardly directed cup-like portion 141 and which bears against both the contact plug means 127 and the fragile closed bottom 145 of the lower vacuum flask 39. The circuit means 135 also includes fastener means, as at 153, having a portion (or bolt member 155) extending through the aperture 143 for attaching the load bearing compression spring means 131 with the electrical conductor non-load-bearing compression spring means 151. Thus, the electrical continuity between the lowermost one of the string of battery cell members 71 28 and the vacuum flask 39 is provided. It should be mentioned that the fastener means 153 preferably includes a pair of shoulder washers, as at 157, and a nut 159.
Particular attention is again directed towards FIGS. 9-11 and 16 of the drawings wherein it may be seen that the upper and lower sub assemblies 31, 33 respectively, include upper and lower pressure vessels, as at 161, 163 for enabling the apparatus 11 to withstand the tremendous pressure inherently existing in the previously described hostile environment. Moreover, it should be noted with reference also being made to FIG. 16 that the apparatus 11 includes means generally indicated at 165 for maintaining a mechanical solidarity of at least the upper vacuum flask 35 and the upper pressure vessel 161, even though the upper pressure vessel 161 may be removed from the interface switch sub means, i.e., for the purpose of accomplishing the necessary initial preparations and/or calibration procedures at the well site.
More specifically, the means 165 alluded to above includes providing the pressure vessel 161 with a pair of vertically disposed elongated slots, as at 167, which are disposed substantially 180° one from the other and which lead upwardly to mouth-like openings, as at 169 in FIG. 16 of the drawings. The flask 35 includes a pair of projecting ears or lugs, as at 171, which are adapted for registration with the slots 167, i.e., being admitted into the slots through the mouth-like openings 169. It should be understood that the upper sub assembly 31 includes a top sub, as at 173, which corresponds to the top sub 512 of the prior art above described. Therefore, it should be sufficient to simply state that the top sub 173 is threaded onto the upper pressure vessel 161 in a manner well known to those skilled in the art. Of course, the top sub 173 closes the mouth-like openings 169. Therefore, the ears 171 are captured within their respective slots 167 when the upper pressure vessel (161 being attached to the top sub 173) is lifted to perform the calibration procedures, etc., at the well site.
Particular attention is now directed towards FIG. 17-20 of the drawings wherein it may be seen that the interface switch sub means 29 is provided with an externally threaded downwardly directed terminus, as at 175, and the lower sub assembly 33 is provided with an internally threaded socket, as at 177, adapted to threadedly engage the downwardly directed terminus 175. It is significant to note that the apparatus 11 includes internally threaded protective cap means, as at 179, adapted to threadedly engage the externally threaded terminus 175 of the switch sub means 29 for providing protection thereof when the apparatus 11 is broken down in the manner above described. In addition, the apparatus includes externally threaded protective plug means, as at 181, adapted to threadedly engage the threaded socket 177 of the lower sub assembly 33 for providing protection thereof when the apparatus is broken down. Of course, the apparatus 11 includes a bottom sub, as at 183, which threadedly engages the lower pressure vessel 163 in somewhat the same manner as does the top sub 173.
The switch sub means 29 is provided with a tapered surface, as at 185, which corresponds to the groove 505 as shown in FIG. 1, for the prior art. Therefore, the tapered surface 185 enables the apparatus 11 to be adapted to the plate 515 as shown in FIGS. 4 and 6 of the drawings.
Additionally, the switch sub means 29 is provided with a tapered hole, as at 187, which corresponds to the tapered hole 504 as shown in FIGS. 1 and 6 of the drawings. Therefore, the apparatus 11 may readily receive the standard telescope type transit instrument 519 as shown in FIG. 6 of the drawings for the purposes outlined earlier in the specification.
Referring again to FIGS. 12-14 of the drawings, it may be seen that the circuit means 135 also includes a first or lower spring loaded plunger assembly, as at 189, which is supported within a suitable socket provided in the battery-pack heat insulation means 97. More specifically, a metallic contact sleeve, as at 191, is adapted to simply slip into the socket provided in the insulation means 97. In addition, a plunger retainer, as at 193, is adapted to threadedly engage the contact sleeve 191, thus capturing the plunger assembly 189.
In addition, a battery pack tie rod, as at 195, preferably formed from stainless steel or the like is included and which has external threads provided at either end thereof. The lower end of the tie rod 195 threadedly engages the contact sleeve 191 while the upper end thereof threadedly engages a first contact button, as at 197. The contact button 197 is simply slip-fitted into an upper socket provided in the heat insulation means 97. Of course, since the tie rod 195 joins the contact sleeve 191 to the first contact button 197, they are captured in their respective sockets.
The circuit means 135 also includes a second or upper spring loaded plunger assembly, as at 199 (FIG. 13) which is very similar to the just described lower spring loaded plunger assembly 189. More specifically, a contact sleeve 201 is slip fitted into a contact insulator, as at 203, which is preferably formed from glass epoxy or the like. The contact insulator 203 is slip fitted into a socket provided in the switch sub body 29 and a plunger retainer, as at 205, threadedly engages the contact sleeve 201.
A switch sub tie rod, as at 207, preferably formed from stainless steel or the like, is included and has the lower end thereof provided with external threads for suitably engaging the contact sleeve 201. The upper end of the tie rod 207 is provided with an enlarged square head, as at 209, which is fitted into an elongated channel, of which the back wall is shown, as at 211, that is suitably provided in the upper end of the switch sub insulation means 95.
A tie rod insulation tube, as at 213, preferably formed from glass epoxy extends through the metal body of the switch sub means 29. The lower end of the insulation tube 213 is received in a suitable socket provided in the contact insulator 203 and the upper end thereof is suitably received in a socket provided in the switch sub heat insulation means 95. The switch sub tie rod 207 extends through the tie rod insulation tube 213.
The circuit means 135 also includes a leaf spring contact member, as at 215 (FIG. 12) which is captured by the tie rod 207. More specifically, the spring contact member 215 is provided with a suitable aperture (not shown) through which the tie rod 207 extends, i.e., being mated prior to the lower end thereof having been threadedly received by the contact sleeve 201.
Also included is a second contact button, as at 217, preferably formed from brass or the like, and which is slip-fitted into a suitably sized socket provided in a voltage regulator housing, as at 219, which is preferably formed from Delrin or the like.
The voltage regulator 73 is attached to the voltage regulator housing 219 by a bolt 221 which has the lower end thereof threadedly received within the second contact button 217. In this manner, electrical contact is also made from the contact button 217 to the voltage regulator 73.
A tapped plate, as at 223, is attached to the first mass of metal 47 by a bolt 225. The tapped plate 223 has a pair of tapped holes, as at 227 (only one of which is shown), for receiving a pair of bolts (only one is shown) as at 229. More specifically, the voltage regulator housing 219 is slip fitted into a socket, as at 231, i.e., provided in the mass of metal 47, after the voltage regulator 73 is attached thereto, and the bolts 229 capture the assembly within the socket 231.
The tapped plate 223 is provided with an aperture, as at 233, which is adapted to be in alignment with an elongated channel, as at 235, which is also provided in the first mass of metal 47.
Referring briefly to FIG. 10 of the drawings wherein it may be seen that a suitable disconnect plug, as at 237, is included as a member of the circuit means 135. Accordingly, it may readily be seen that suitable electrical conductors (not shown) may be made to extend through the aperture 233 and the elongated channel 235 for connecting the disconnect plug 237 with the voltage regulator 73. Of course, the gyro-compass 13 is provided with a suitable compatible disconnect plug (not shown) for electrical engagement with the disconnect plug 237, i.e., thus connecting the electric motor 15 with the just described circuit means 135.
It should also be mentioned at this point that the apparatus 11 is provided with suitable means, as at 239 (FIG. 10), for making the necessary electrical connection when performing the initial preparations and/or calibration procedures at the well site. Of course, the means 239 will include switch means (not shown) for starting the electric motor 15.
Operation--the apparatus 11 is intended to be transported to the well site in a broken down configuration. More specifically, the upper and lower sub assemblies 31, 33 are separated at the threaded terminus 175 (FIG. 17) and the protective cap means 179 is suitably placed over the threaded terminus 175.
Likewise, the protective plug means 181 is suitably inserted in the socket 173 (FIG. 18). Therefore, the apparatus 11 may quickly and easily be reassembled at the well site to the configuration of that shown in FIG. 8 of the drawings. The set up and calibration procedures for the apparatus 11 are substantially identical to the set up and calibration procedures of the previous gyrocompass directional surveying instrument and as fully outlined earlier in the specification. However, a few significant features of the apparatus 11 will be discussed briefly and with particular reference being made to FIGS. 9 and 10 of the drawings.
The upper pressure vessel 161 is adapted to threadedly engage the switch sub means 29, i.e., even though thread structure is not shown in FIG. 10 of the drawings. Thus, the upper pressure vessel 161 is disengaged from the switch sub means 29 while it is restingly supported by the arrangement as shown in FIG. 5 of the drawings. As mentioned previously, the upper vacuum flask 35 is removed simultaneously with the upper pressure vessel 161, thus exposing the tubular heat sink means 49 which is very light weight aluminum or the like. Therefore, depressing on the spring loaded plunger means 87 enables the tubular heat sink means 49 to be manually lifted upwardly so as to gain access to the above mentioned means 239 for accomplishing the initial preparations and/or calibration procedures.
After these procedures are completed, the tubular heat sink means 49 may be replaced by bringing it down over the various instruments, i.e., not only the gyrocompass 13, but the inclinometer 19 and the camera means 21. It will be obvious to those skilled in the art that due to the delicate nature of these instruments, coupling these components together results in connections that are weak at best and subject to misalignment or damage if moment loads are imposed on them. Therefore, the tubular heat sink means 49 precludes the likelihood of these instruments sustaining physical damage as a result of removing and replacing the upper pressure vessel 161.
The shock absorber 75 (FIG. 9) registers with the inside of the tubular heat sink means 49 for precluding any shifting of the instruments contained within the tubular heat sink means 49.
Inertia loads on the lower vacuum flask 39 (FIG. 11) are minimized in that when the batteries 71 move downward relative to the apparatus 11 because of inertia forces, a portion of the energy present will be stored by the shock absorber means 105, i.e., the load bearing compression spring means 131 (FIG. 15). The remaining energy is converted to a force on the contact plug means 127 which transfers this force to the battery tube means 101, the battery tube means 101 to the battery pack heat insulation means 97, thence to the outer wall 67 of the vacuum flask 39. This arrangement insures that none of the inertia forces will be imposed on the inner wall 65 of the vacuum flask 39, but rather on the outer wall 67 which, being of a heavier material, is better able to withstand the same. The spring loaded plunger assembly 189 has sufficient travel capability to accommodate battery movements and yet maintain optimum electrical continuity.
From FIG. 11 of the drawings it may also be seen that the bottom sub 183 has machined into it a socket, as at 241, for accommodating the bottom of lower vacuum flask 39. The interior space, shown as at 243, but which also includes the spaced distance 147 (FIG. 15), of the lower vacuum flask 39, is sealably closed at its upper end by the battery pack heat insulation means 97 which engages the flask 39 by means of a threaded connection, as at 245. The heat insulation means 97 is fitted with O-rings, as at 247, to prevent air entry into the interior storage space 253 of the vacuum flask 39.
In addition, O-rings, as at 249 (FIG. 10), provide an air-tight seal between the switch sub means 29 and the lower pressure vessel 163. Likewise, O-rings, as at 251, provide an air-tight seal between the switch sub means 29 and the upper pressure vessel 161.
The interior or storage space, as at 253, of the upper vacuum flask 35 is provided with an air tight seal by a pair of O-rings, as at 255, i.e., the O-rings 255 being received in grooves, as at 257, provided in the switch sub heat insulation means 95.
Although the invention has been described and illustrated with respect to a preferred embodiment thereof, it should be understood that it is not intended to be so limited since changes and modifications may be made therein which are within the full intended scope of the invention.
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Apparatus used for the directional surveying of deep wells, i.e., 20,000-25,000 feet (6,096 meters-7,620 meters), and which is specifically identified as a gyroscopic directional surveying instrument having a high pressure and a high temperature capability, e.g., 24,000 pounds per square inch (1,632.65 atmospheres) and 450° F. (232.22° C.). While in its fully assembled configuration, the apparatus may be described as being exceptionally long (or at times unwieldy), e.g., 12-16 feet long (3.66 meters-4.88 meters), it is quite remarkable that it does not exceed three inches (76.2 millimeters) in diameter. Therefore, it may readily be lowered into the small diameter steel casing normally defining the walls of these deep wells. In view of its cumbersomeness, it is significant to note that the apparatus may readily be broken-down into upper and lower sub-assemblies when being transported to or from the well site. Moreover, structure is included for individually protecting each sub-assembly from the adverse affects of the extreme pressure and temperature. Therewith, the feasibility of "on site" mating and demating of these sub-assemblies is achieved. Equally significant is that structure is included which readily enables the required physical access--at the " on site" location--to the internally disposed gyrocompass, inclinometer, and camera systems, i.e., for the purpose of accomplishing certain initial preparations and/or calibration procedures.
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This invention relates to the preparation of dialkoxy benzoic acid and more particularly to their preparation by direct metalation of 1,3-dialkoxybenzene.
BACKGROUND OF THE INVENTION
Dialkoxy benzoic acids have been prepared by metalation of 1,3-dialkoxybenzene acid with butyl lithium, Chem. Abstracts 95: 132423m; butyl lithium and ethyl lithium, U.S. Pat. No. 4,399,078; t-butyl sodium, Chem Abstracts 86: 42548r; and phenyl sodium, Japanese Published Application No. 68 22,969 (Chem Abst. 70: 77600y). These procedures require multiple reaction steps of first forming the metal organic reactant and then reacting it to metalate the dialkoxy benzene. The metalated dialkoxybenzene is carbonated and acidified to form benzoic acid.
BRIEF DESCRIPTION OF THE INVENTION
It is an object of this invention to provide a method for making dialkoxy benzoic acid comprising the metalation of 1,3-dialkoxybenzene by direct reaction with potassium metal.
In accordance with this invention dispersed potassium and 1,3-dialkoxybenzene are contacted in the presence of an amine solvent and an electron acceptor reactive with potassium such as α-methylstyrene, whereby the dialkoxybenzene is metalated, and the reaction mixture is carbonated and acidified in a conventional manner to precipitate the dialkoxy benzoic acid.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The reaction of the invention is represented by the equation ##STR1## where R 1 and R 2 are independently a lower alkyl radical, suitably containing up to 5 carbon atoms. UH is an electron acceptor reactive with potassium to form a free radical intermediate, suitably conjugated unsaturated hydrocarbons such as, for example styrene, α-methyl styrene, diisopropenyl benzene or biphenyl, or a fused ring aromatic compound having from 2 to 5 fused rings with or without substituent alkyl groups, such as, for example, naphthalene, phenanthrene, anthracene, acenaphthene, fluorene and pyrene. A substantially stoichiometric amount of electron acceptor is used, that is, one-half the molar quantity of potassium. If the electron acceptor is polymerizable, such as methyl styrene, excess of stoichiometric is to be avoided. SH is the saturated hydrocarbon corresponding to the electron acceptor used.
The dialkoxybenzene is also used in substantially stoichiometric amounts, that is one mol for each mol of potassium.
The reaction is carried out in a tertiary amine solvent, suitably a trialkyl amine, cyclic amine or tetraalkylethylenediamine or mixtures thereof, such as, for example, triethylamine, tetramethylethylenediamine, or 1-methylpyrollidine.
The reaction proceeds readily at slightly elevated temperatures, suitably 60°-80° C. Temperatures above about 100° C. should be avoided to avoid decreased yield and reaction rates are very slow at temperatures as low as room temperature.
In an illustrative example of the invention, a three-necked, 500 ml. Morton flask is equipped with a mechanical stirrer, thermometer, reflux condenser and 60 ml. pressure equalizing funnel. 3.75 g. of potassium, 140 ml. triethylamine and a drop of a potassium dispersing reagent (chlorobenzene) was charged to the flask under nitrogen and the potassium was dispersed at 70° C. A solution of α-methyl styrene (5.67 g.), 1,3-dimethoxybenzene (12.06 g.) and tetramethylethylenediamine (15 ml.) in triethylamine (20 ml.) was added dropwise over a period of 69 minutes. The mixture was stirred at 70° C. for three hours after the addition. The entire reaction mixture was quenched and carbonated by pouring it over crushed dry ice (456 g.) and then allowed to warm to room temperature. The volatile components were removed from the carbonated mixture with a rotary evaporator and the resultant solids were partitioned between diethyl ether (30 ml.) and water which was extracted with diethyl ether (4 times, 30 ml.) The aqueous layer was acidified with concentrated hydrochloric acid to pH 1. The resultant precipitate, water washed and air dried, was 2,6-dimethoxybenzoic acid (13.56 g.).
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2,6-dialkoxybenzoic acid is made by direct metalation of 1,3-dialkoxybenzene by potassium. The metalated dialkoxybenzene is carbonated and acidified to form the dialkoxybenzoic acid.
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[0001] This application is a U.S. national-phase application of International Application No. PCT/IT00/00547.
TECHNICAL FIELD
[0002] The present invention relates to a snow-board binding.
TECHNOLOGICAL BACKGROUND
[0003] In the technical field referred to, a need has arisen to facilitate the fitting and adjustment of snow board bindings on footwear so that they can be adapted to the snowboarder's various requirements as well as to the existing shapes of foot and footwear.
[0004] In most cases, the footwear is held on the base of the binding by two or more strap fastenings, each formed by two straps which can be closed onto one another by a fastening device for varying the extent to which the straps are tightened onto the user's footwear. Both straps of the strap fastening are made of relatively stiff plastic material to ensure the necessary support and clamping of the footwear during sports activities.
[0005] However, owing to the stiffness of the material, the fitting of the binding on the footwear is obstructed by the two straps of the strap fastening which have to be deformed resiliently in order to move them apart for this purpose.
[0006] Typical snow board bindings are disclosed in International Patent Publication No. WO 00/76603.
DESCRIPTION OF THE INVENTION
[0007] The main object of the invention is to provide a snow board binding including at least one strap fastening which is designed structurally and functionally for more convenient fitting on the footwear and improved adaptability to varied shapes of foot and/or footwear.
[0008] A further object of the invention is to optimize the coupling between the footwear and the binding.
[0009] Yet another object of the invention is to render the operations necessary to adjust the binding particularly quick and easy.
[0010] These objects and others which will become clearer from the following description are achieved by providing a snow-board binding formed in accordance with the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The characteristics and the advantages of the invention will become clearer from the detailed description of a preferred but not exclusive embodiment thereof, described by way of non-limiting example with reference to the appended drawings in which:
[0012] [0012]FIG. 1 is a perspective view of a snow board binding according to the invention,
[0013] [0013]FIG. 2 is a view showing a detail of the binding on an enlarged scale and sectioned on the line II-II of FIG. 1, and
[0014] [0014]FIG. 3 is a further, partial perspective view of the binding of FIG. 1.
PREFERRED EMBODIMENT OF THE INVENTION
[0015] With reference to FIG. 1, a snow board binding formed in accordance with the present invention is generally indicated by reference number 1 .
[0016] The binding 1 comprises a base 2 which can house a snow board shoe or boot (not shown) and is arranged to be fixed to a snow board 2 a (shown partially) in an angularly adjustable manner by a conventional connection mechanism 4 , shown partially.
[0017] The base 2 has two facing and opposed side walls 3 a , 3 b , which are connected at the rear by a bridge-like support 3 c , together defining a seat for housing the user's shoe or boot.
[0018] The binding 1 further comprises a pair of strap fastenings, that is, a rear strap fastening 5 and a front strap fastening 6 , for holding the shoe or boot on the base 2 . The rear strap fastening 5 is connected to the base 2 in the manner described below so as to act on the instep and ankle region of the user's foot, and the upper surface of the foot is acted on by the front strap fastening 6 .
[0019] Each strap fastening 5 , 6 comprises two straps 5 a , 5 b or 6 a , 6 b , respectively, between which a respective adjustable fastening 9 , 10 is disposed.
[0020] Each of the straps 5 a , 6 a comprises a toothed portion 7 and is anchored by one end 11 in a compartment 12 of the respective side wall 3 a so as to be pivotable about an axis 13 .
[0021] The strap 6 b is anchored by one of its ends 14 in a compartment 15 of the respective side wall 3 b so as to be pivotable about an axis 16 . The strap 6 b carries, at its free end, the adjustable fastening 10 which is of the type that is arranged for bringing about unidirectional, manually released clamping onto the toothed portion 7 of the strap 6 a.
[0022] The strap 5 b of the strap fastening 5 comprises a first portion which connects it to the base 2 and which is in the form of a loop 17 of flexible metal cable covered by a sheath of plastic material and closed onto itself around an anchoring pin 18 . To prevent extreme angles of wrapping of the metal cable, a pulley 19 is interposed between the loop 17 and the pin 18 and the whole is housed and protected in a compartment 20 of the side wall 3 b . At the end remote from the pulley 19 , the loop 17 is anchored in an adjustable position on teeth 21 of a rack 22 .
[0023] The rack 22 is protected by a cover 22 a provided with holes 22 b through which it is possible to see the underlying teeth 21 and thus to select the point of engagement of the loop 17 for the desired adjustment. The rack 22 is in turn fixed on top of a second portion 23 of the strap 5 b in the form of an element for distributing the clamping load of the rear strap fastening 5 over the user's instep. The rack 22 is fixed by two screws 32 , 33 which also have the function of anchoring the cover 22 a on the rack 22 . The second portion 23 is widened and padded and is also equipped with a fairly stiff covering band 24 of plastic material on which the adjustable fastening 9 is anchored.
[0024] The adjustable fastening 9 is of known type with a lever 25 pivoting on a base 26 and provided with teeth 27 for engaging the toothed portion 7 of the strap 5 a and pulling it along in the closure direction upon each operative pivoting movement on the base 26 . The adjustable fastening 10 also comprises a pawl 28 mounted on the base 26 and acting on the toothed portion 7 in order to restrain the strap 5 a unidirectionally. It will also be noted that a seat 29 is provided between the covering band 24 and the padded portion of the load-distributing element for the concealed housing of the portion of the strap 5 a which projects beyond the adjustable fastening 10 as a result of the tightening of the rear strap fastening 5 . The opening 29 a of this seat 29 is visible in FIG. 3.
[0025] Finally, the binding 1 is equipped with a rear support 30 connected for pivoting between the side walls 3 a , 3 b , for example, on pins 18 and 31 .
[0026] In operation, during the fitting of the binding 1 on the footwear, the strap 5 a of the rear strap fastening 5 , which is conventionally the stiffer strap owing to the need to incorporate the element for distributing the clamping load of the rear strap fastening 5 over the instep of the user's foot, can easily be opened out, owing to the considerable intrinsic flexibility of the first, metal loop 17 which not only allows the two straps 5 a , 5 b of the rear strap fastening 5 to be opened out easily but even allows the strap 5 b to be left resting on the snow-board in the opened-out condition, enabling the binding 1 to be fitted on the footwear without using one's hands.
[0027] Once fitted on the footwear, the binding 1 is tightened thereon by the adjustable fastenings 9 and 10 . If necessary, the length of the strap 5 b can be adjusted beforehand by changing the tooth 21 of the rack 22 on which the loop 17 is engaged.
[0028] The front strap fastening 6 may also have a structure similar to that of the rear strap fastening 5 described herein, with the same adjustment capabilities and flexibility. Moreover, the loop 17 may be made of non-metallic materials such as synthetic fibres, plastics materials, etc.
[0029] The present invention thus achieves the objects proposed, offering many advantages over the bindings of the prior art.
[0030] A first advantage is an extremely quick and easy fitting of the binding on the footwear since the strap fastening can be subjected to twisting or pivoting of any kind in the region of the metal loop without effort on the part of the user so that it does not obstruct the positioning of the footwear on the base of the binding.
[0031] Another advantage is that the cable used for the loop has a metal core, since this allows the cable to be very thin, favoring its flexibility but nevertheless ensuring its tensile strength.
[0032] Moreover, the binding can be adapted in many ways to varied morphological shapes of foot or to various types of footwear.
[0033] Finally, the adjustment both of the overall length of the strap fastening and of its inclination relative to the base of the binding is particularly easy.
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A snow-board binding is described and comprises a base ( 2 ) for supporting a footwear, at least one strap fastening ( 5, 6 ) connected to the base for restraining the footwear on the base ( 2 ), and means for connecting means comprising a first portion ( 17 ) of the strap fastening ( 5, 6 ) having greater flexibility than any remaining portion of the strap fastening.
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BACKGROUND OF THE INVENTION
The field of this invention pertains to calcium phosphate minerals for bone cement or bone filler applications and in the preparation of such cement. More specifically, this invention relates to a calcium phosphate bone cement comprising a mixture of tetra-calcium phosphate and di-calcium phosphate in an aqueous solution, in which the mixture then sets to form a bone cement with a substantial portion of the cement being hydroxyapatite.
Hydroxyapatite is the major natural building block of bone and teeth. It has been found useful in fixing fractures and bone defects to use bone cements which are formed by combining calcium and phosphate precursors in an aqueous solution which initially forms a paste but then hardens into a hydroxyapatite bone cement. Hydroxyapatite has a calcium-to-phosphorous ratio of approximately 1.67 which is generally the same as the calcium phosphate ratio in natural bone structures. The paste may be placed in situ prior to setting in situations where bone has been broken, destroyed, degraded, become too brittle or has been the subject of other deteriorating effects. Numerous calcium phosphate bone cements have been proposed such as those taught by Brown and Chow in U.S. Reissue Pat. No. 33,161 and 33,221, Chow and Takagi in U.S. Pat. 5,522,893, and by Constantz in U.S. Pat. Nos. 4,880,610 and 5,047,031, the teachings of these patents are incorporated herein by reference.
It has been well known since the initial use of calcium phosphate cements that the addition of sodium phosphate solutions, potassium phosphate solutions or sodium carbonate solutions to the aqueous setting solution of the calcium phosphate precursors can speed setting times. This is documented in the Chow et al., April, 1991 IADR Abstract No.: 2410 and AADR, 1992 Abstract No.: 666 and was known to those skilled in the art prior to these publications.
Typically, the powdered component, which may be a combination of tetracalcium phosphate and dicalcium phosphate is supplied in a sterile form in a blister pack or a bottle, e.g., with contents of 2 to 25 g. The liquid, e.g. a molar sodium phosphate solution, distilled water or sodium chloride solution is usually present in a sterile, glass container, usually a disposable syringe, having a volume of 10 cc. The powdered and liquid components are usually mixed in a vessel, and processed from this vessel, e.g., by means of a syringe or the like.
It is important that these components of bone cements have long-term stability during storage as these components may be stored for over weeks and months before the actual cement usage when the powdered component is mixed with the aqueous component to form a settable material. But, the long-term stability of these components have not been extensively studied because it has been assumed by those skilled in the art that they stay stable with little or no change in properties.
However, unlike the industry's general assumption, according to Gbirecl et al. in Factors Influencing Calcium Phosphate Cement Shelf - life , it has been found that some prior art powder mixtures of calcium phosphate lose their ability to set after 7 days of storage, despite being store in sealed containers. The deterioration of the prior art powder mixtures was subsequently found to be related to their conversion to monetite in a dry state during ageing.
Thus, there is a need to develop a rapid setting bone cement which overcomes the destabilization problems of the prior art. This need is fulfilled by the invention that is described herein.
SUMMARY OF THE INVENTION
It is an aspect of the invention to provide a rapid setting calcium phosphate bone cement with long-term shelf-life.
Furthermore, it is an aspect of the invention to provide a method for making a rapid setting bone cement with long-term shelf-life and supplying the same as a kit.
In the preferred embodiment, a first powdered component of the rapid setting bone cement comprises stabilized dicalcium phosphate dihydrous (DCPD) that contains about 10 ppm to about 60 ppm of magnesium, preferably about 30 ppm to about 50 ppm of magnesium, which is added as a stabilizing agent during the wet chemical precipitation process used to form the stabilized DCPD. This process will be described in detail in the examples below. The source of the magnesium used to stabilize dicalcium phosphate dihydrous is from MgO, MgO 2 , Mg(OH) 2 , MgHPO 4 , MgHPO 4 .3H 2 O, MgHPO 4 .7H 2 O, Mg 3 (PO 4 ) 2 , Mg 3 (PO 4 ) 2 .4H 2 O, Mg 3 (PO 4 ) 2 .8H 2 O, Mg 3 (PO 4 ) 2 .22H 2 O, MgCO 3 , MgCO 3 .3H 2 O, MgCO 3 .5H 2 O, 3MgCO 3 Mg(OH) 2 .3H 2 O, MgCO 3 Mg(OH) 2 .3H 2 O, Mg(C 3 H 5 O 3 ) 2 .3H 2 O, MgC 2 O 4 .2H 2 O, Mg(C 4 H 4 O 6 ) 2 .4H 2 O, MgCO 3 .CaCO 3 , Mg 2 P 2 O 7 , Mg(C 12 H 23 O 2 ) 2 .2H 2 O, Mg(C 14 H 27 O 2 ) 2 , Mg(C 18 H 33 O 2 ) 2 , or Mg(C 18 H 35 O 2 ) 2 or a mixture thereof. The preferred source of magnesium to stabilize DCPD is magnesium oxide. The first powdered component may also comprise other calcium phosphate minerals other than dicalcium phosphate dihydrous.
A second powdered component of the rapid setting bone cement comprises at least one calcium phosphate mineral other than the stabilized dicalcium phosphate dihydrous such as tetra-calcium phosphate, di-calcium phosphate, tri-calcium phosphate, mono-calcium phosphate, β-tricalcium phosphate, α-tricalcium phosphate, oxypatite, or hydroxypatite or a mixture thereof. The preferred calcium phosphate mineral other than the stabilized dicalcium phosphate dihydrous is tetracalcium phosphate (TTCP).
The liquid component of the rapid setting bone cement comprises water and other ionic solution which help setting times. The preferred third liquid component comprises a water-based solution of at least one sodium phosphate and trisodium citrate. Examples of sodium phosphates which can used in the invention are disodium hydrogen phosphate anhydrous, sodium dihydrogen phosphate monohydrate, sodium phosphate monobasic monohydrate, sodium phosphate monobasic dihydrate, sodium phosphate dibasic dihydrate, trisodium phosphate dodecahydrate, or dibasic sodium phosphate heptahydrate, pentasodium tripolyphosphate, sodium metaphosphate, or a mixture thereof. The most preferred third liquid component comprises a water-based solution of disodium hydrogen phosphate anhydrous, sodium dihydrogen phosphate monohydrate and tri-sodium citrate.
In another preferred embodiment, a calcium phosphate cement comprises a powdered first component comprising stabilized dicalcium phosphate dihydrous containing magnesium; a powdered second component comprising at least one calcium phosphate mineral other than said stabilized dicalcium phosphate dihydrous; and a liquid third component comprising water, wherein said cement is storage stable such that said stabilized dicalcium phosphate dihydrous containing magnesium exhibits characteristic x-ray diffraction peaks corresponding to those of dicalcium phosphate dihyrous after 1 year of storage at 25° C. in a sealed container or after an accelerated ageing test of 52 days at 50° C. in a sealed container.
In yet another preferred embodiment, a calcium phosphate cement comprises a powdered first component comprising stabilized dicalcium phosphate dihydrous containing magnesium; a powdered second component comprising at least one calcium phosphate mineral other than said stabilized dicalcium phosphate dihydrous; and a liquid third component comprising water, wherein said cement is storage stable such that said stabilized dicalcium phosphate dihydrous containing magnesium exhibits x-ray diffraction peaks at 11.605, 20,787, 23.391, 26.5, 29.16, 30.484, 31.249, 31.936, 33.538, 34.062, 35.45, 36.34 and 39.67±0.2 degrees two-theta after 1 year of storage at 25° C. in a sealed container or after an accelerated ageing test of 52 days at 50° C. in a sealed container.
In another preferred embodiment, a method for forming a calcium phosphate bone cement comprises: (a) producing a powdered first component comprising stabilized dicalcium phosphate dihydrous containing from about 10 ppm to 60 ppm of magnesium using a wet chemical precipitation process, (b) producing a powdered second component comprising at least one calcium phosphate mineral other than said stabilized dicalcium phosphate dihydrous, and (c) reacting said first and second powdered components with an aqueous liquid component causing a reaction which forms a settable material.
In another preferred embodiment, a method for forming a calcium phosphate bone cement comprises: (a) producing a powdered first component comprising stabilized dicalcium phosphate dihydrous containing magnesium using a wet chemical precipitation process such that said stabilized dicalcium phosphate dihydrous containing magnesium exhibits characteristic x-ray diffraction peaks corresponding to those of dicalcium phosphate dihydrous after 1 year of storage at 25° C. in a sealed container or after an accelerated ageing test of 52 days at 50° C. in a sealed container, (b) producing a powdered second component comprising at least one calcium phosphate mineral other than said stabilized dicalcium phosphate dihydrous, and (c) reacting said first and second powdered components with an aqueous liquid component causing a reaction which forms a settable material.
In yet another preferred embodiment, a kit for forming a calcium phosphate bone cement comprises: (a) a first container containing a mixture of a powdered first component comprising stabilized dicalcium phosphate dihydrous containing from about 10 ppm to 60 ppm of magnesium, and a powdered second component comprising tetra calcium phosphate; and (b) an aqueous liquid component in a second container, wherein the aqueous liquid component comprises at least one sodium phosphate. The aqueous liquid component of the kit may further comprise tri-sodium citrate.
In yet another preferred embodiment, a kit for forming a calcium phosphate bone cement comprises: (a) a first container containing a mixture of a powdered first component comprising stabilized dicalcium phosphate dihydrous containing magnesium such that the x-ray diffraction pattern of said stabilized dicalcium phosphate dihydrous remains substantially the same after 1 year of storage at 25° C. in a sealed container or after an accelerated ageing test of 52 days at 50° C. in a sealed container; and (b) an aqueous liquid component in a second container, wherein the aqueous liquid component comprises at least one sodium phosphate. The aqueous liquid component of the kit may further comprise tri-sodium citrate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a characteristic X-ray powder diffraction pattern of DCPD containing 40 ppm of magnesium before the accelerated ageing test.
FIG. 2 is a characteristic X-ray powder diffraction pattern of DCPD containing 40 ppm of magnesium after the accelerated ageing test (i.e., after storage at 50° C. for 77 days).
FIG. 3 is a characteristic X-ray powder diffraction pattern of DCPD containing 60 ppm of magnesium before the accelerated ageing test.
FIG. 4 is a characteristic X-ray powder diffraction pattern of DCPD containing 60 ppm of magnesium after the accelerated ageing test (i.e., after storage at 50° C. for 90 days).
DETAILED DESCRIPTION
This invention is illustrated by, but not limited to, the following examples. Although the following Examples may recite a certain order of steps of making the invention, the invention is not in anyway limited to the order written.
EXAMPLE 1
A. Production of Dicalcium Phosphate Dihydrous with 40 ppm of Magnesium
(1) 30% Phosphoric Acid Solution Preparation with 40 ppm Magnesium Addition.
To make the required 30% concentration of orthophosphoric acid (H 3 PO 4 ), in a 5 ltr stainless beaker, 261±2 mls of 85% orthophosphoric acid was added to 737±2 mls of deionized water and the beaker was placed on top of a hot plate set to 45° C. Then the temperature probe was placed in the beaker to measure the temperature of the acid solution and the hot plate was turned on to heat the solution to 45° C. The solution was then stirred at a speed of 200±10 rpm to ensure that the probe was measuring a true representation of the beaker content. While the acid solution was being heated to 45° C., 0.0413 grams of magnesium oxide (MgO) (equivalent to about 40 ppm magnesium content or about 0.006883% based on the weight of the DCPD) was added to the solution. Then the pH probes and temperature probes were calibrated and put into the acid solution.
(2) Preparation of Calcium Carbonate Solution
0.45 kg of calcium carbonate (CaCO 3 ) was added into a 5 kg stainless steel beaker and 1 ltr of deionized water was added to the beaker. The beaker was then placed on top of a hot plate which was set to 40° C. Then the temperature probe was placed into the calcium carbonate suspension and the hot plate was turned on. The calcium carbonate suspension was then stirred at a speed of 575±50 rpm to ensure that the probe was measuring a true representation of the beaker content.
(3) Wet Chemical Precipitation
Once the magnesium spiked orthophosphoric acid reached the temperature of 45° C. and calcium carbonate suspension reached the temperature of 40° C., Watson-Marlow's Model 323u/D peristaltic pump system was set up to feed the carbonate suspension into the magnesium spiked orthophosphoric acid at a feed rate of 48±2 ml/min. The pH probe was activated in order to obtain the temperature/pH/time data at the start. Then the carbonate suspension was fed into the acid solution. Once the pH of the acid solution reached a pH of ˜3.6, the feed rate of the carbonate suspension was stopped and the pH of the solution was monitored. The pH data from the beginning till the end of the carbonate feed was recorded. Once the pH reached 4.75, the final temperature/pH/time data for the precipitate was recorded and all the temperature and pH probes as well as the peristaltic tube from the solution were removed. The reaction of magnesium, orthophosphoric acid and calcium carbonate produced the stabilized DCPD precipitate.
(4) Precipitate Rinsing
A Whatman #5 filter paper (2.5 μm pore size) was placed into each Buckner funnel attached to a Buckner flask. Five (5) Buckner funnels attached to Buckner flasks were needed per precipitation run. Then, the precipitate solution (approximately 300 ml) was poured into each Buckner funnel attached to a Buckner flask and then a vacuum pump was turned on. The pump drew a vacuum and caused the water to be removed from the precipitate while the filter paper kept the precipitate in the Buckner funnel. After a minimum of two minutes of suction, each Buckner funnel was filled to the rim with deionized water (approx. 200-300 ml) in order to rinse any excess reactants from the precipitate. The precipitate was left under the vacuum for a minimum time of 5 minutes in order to ensure removal of any excessive free moisture.
(5) Freeze Drying
Next, a maximum of 300 grams (approximately half a precipitate production yield) was placed per freeze-drying tray in a manner ensuring that the precipitate is spread out evenly on the tray. The filled trays were then placed into Biopharma Process System's Model VirTis Genesis 25 Super ES freeze dryer. Each tray contained a temperature probe in order to monitor the precipitate temperature/moisture level during drying. Then the freeze dryer cycle was set to the program listed below and was turned on.
TABLE 1
Freeze Drying Recipe For DCPD
Step
Temperature (° C.)
Time (minutes)
Vacuum (mTorr)
*R
−15
1
100
**H
−15
120
100
R
−5
120
200
H
−5
240
200
R
0
120
1000
H
0
600
1000
R
10
60
1000
H
10
30
1000
R
20
60
1000
H
20
30
1000
*R = Ramp section of the freeze drying cycle.
**H = Hold section of the freeze drying cycle.
Once the precipitate has been dried using the freeze-drying cycle listed in Table 1, the precipitate required milling in order to reduce the average particle size so as to improve the final cement handling and setting properties. This milling is performed using Glen Creston Ltd's Model BM-6 roller ball-mill.
(6) Ball-Milling
3000±30 grams of alumina milling media (13.0 mm diameter×13.2 mm height) was placed into each ball-mill jar. Then, 500+/−25 grams of the dried DCPD precipitates were added into each ball-mill jar and were placed on the ball-mill rollers. The ball-mill was set to 170 rpm and a mill time of 30 minutes, and was turned on.
The ball-mill jar speed was monitored to ensure that it is rotating at 85 rpm. Once the 30 minutes of milling has elapsed, the milling media was separated from the milled powder by sieving through the 8 mm screen provided. The milled and sieved powders have a particle size within a range of about 0.4 to 200 μm, preferably about 35±20 μm, as measured by Beckman Coulter Counter's Model LS 13320 Series particle size analyzer. The milled and sieved powders were then placed into the freeze-drying trays and the freeze-drying procedure as detailed in the previous section was repeated.
B. Production of Tetra Calcium Phosphate (TTCP)
(1) TTCP Cake Preparation
To form the prefrerred TTCP, the TTCP slurry mixture needs to comprise a 50% w/w solution of solid to liquid with the solid component comprising 60.15% dicalcium phosphate anhydrous (DCPA) and 39.85% CaCO 3 and the liquid component comprising purified water. To prepare a batch of TTCP “cakes” for sintering in the furnace, i.e., 3500 grams of TTCP cakes, 2105.25+/−0.5 grams of DCPA was accurately weighed out into a clean 5 liter Buckner flask. To this, 1394.75+/−0.5 grams of CaCO 3 were added. To this powder mixture, 3.5 liters of deionized water was added. Table 2 shows the specific amounts and percentages of these components.
TABLE 2
Raw Material Weights For The Production Of TTCP Cakes
Material
Weight (g)
Ratio (%)
CaCO 3
1394.75 ± 1
39.85
DCPA
2105.25 ± 1
60.15
Water
3500.00 ± 10
100
The Buckner flask was then sealed with appropriate rubber bung and nozzle attachments. The Buckner flask was placed in Glen Creston Ltd's Model T10-B turbular mixer for 20 minutes for homogenous mixing. Table 3 shows the turbular blending parameters.
TABLE 3
Turbular Parameters For Blending Of TTCP Raw Materials
Parameter
Setting
Speed (rpm)
44 ± 4
Time (mins)
20
Buckner Flask Volume (%)
80
While the Buckner flask was mixing, the appropriate vacuum tubing to a four-point manifold was connected: one end was attached to the vacuum pump, the other four points were attached to the nozzle attachments on four Buckner flasks. A 9 cm diameter polypropylene Buckner funnel was assembled onto each of the four Buckner flasks, respectively, and Whatman grade 5 filter paper was placed into each Buckner funnel. The blended DCPA/CaCO 3 /water mixture was removed from the turbular mixer, and the rubber bung was removed. Then, each polypropylene Buckner funnel was completely filled with the TTCP slurry. The TTCP slurry was vacuum dried using the vacuum pump, and the vacuum was drawn for a minimum of 5 minutes until the cakes formed solid top surfaces. Further vacuum drying could be used if required to form solid cakes. Once the cakes were formed, the vacuum on the Buckner flasks was released. Each funnel was removed from the flask and the inverted funnel was gently tapped to remove the cake. Each funnel produced a cake of approximately 300 grams.
Then the spent filter paper was removed, the funnel was washed out with purified water and a fresh filter paper was placed in the funnel. The above steps were repeated until all the slurry solution is in a cake form. The TTCP slurry was hand mixed every four to five cake preparations to ensure homogeneity. If upon removal from the funnel, the cake was broken or has a rough surface, the deionized water was sprayed onto the surface to bind loose fragments together. Any loose remaining fragments were reintroduced to the slurry mixture to form new cakes.
(2) Sintering
All cakes were stacked onto a stainless steel tray and dried for two hours at 200° C. in Lenton's Model AWF 12/42 muffle furnace to drive off excess moisture prior to sintering. The TTCP cakes were now ready to be sintered using the sintering program detailed in Table 4.
TABLE 4
Sintering Parameters For Firing Of TTCP Cakes
Step
Temperature (° C.)
Time (minutes)
Ramp Rate (° C./min)
Ramp
800
100
8
Dwell
800
≧120
n/a
Ramp
1550
94
8
Dwell
1550
720
n/a
Cool
800
≦10
75
Cool
20
15
52
The sintered cakes were transferred to a vacuum Buckner flask before the temperature dropped below 150° C. unless the material was to be crushed and milled immediately.
(3) Jaw Crushing
TTCP was processed through Glen Creston's jaw crusher to reduce the granules to a manageable size, preferably in the range of about 2.5 to 7.5 mm prior to processing through the co-mill. The sintered TTCP cakes were manually broken using a mortar and pestle to particle sizes of approximately one inch in diameter before loading into the jaw crusher. In this instance, the jaw crusher gap was set to 5 mm.
(4) Co-Milling of TTCP Granules
TTCP was processed through Quadro Inc.'s co-mill (Model Quadro Comil 197) to reduce the material to the final particle size. The mill speed was set to 5000+/−300 rpm. The impeller gap was set to 0.375″ using stainless steel washers. To co-mill the TTCP powder, the jaw-crushed TTCP powders were slowly fed into the co-mill at a rate of approximately 700 grams/min, ensuring that the co-mill did not become clogged with excess powder. (See Table 5 for co-milling parameters.)
TABLE 5 Parameters For Co-Milling The Jaw-Crushed Sintered TTCP Cakes Parameter Setting Screen No. 0.024″ Impeller speed 5000 rpm
(5) Ball-Milling
Glen Creston Ltd's Model BM-6 roller ball mill was used to ball-mill the sintered, jaw crushed and co-milled TTCP. The ball milling parameters for the dry milling of the sintered, jaw crushed and co-milled TTCP are listed in Table 6. For the dry milling of the TTCP, a total of 3000±50 grams of alumina milling media (13.0 mm diameter×13.2 mm height) was weighed into an alumina ball-milling jars to which 850 grams of the TTCP was added. The ball mill parameters are outlined in Table 6 below.
TABLE 6
Milling Parameters For The Dry Ball-Milling Of TTCP
TTCP Ball Mill Parameters
Speed (rpm)
85
Time (mins)
420
Media fill weight (grams)
3000 +/− 50
TTCP weight (grams)
850
C. Production of Water-Based Solution of Sodium Phosphate and Trisodium Citrate:
Into one liter of high purity water, 22.8 grams of di-sodium hydrogen phosphate anhydrous, 45.5 grams of sodium dihydrogen phosphate monohydrate and 147.1 grams of tri-sodium citrate were added and stirred until they were completely dissolved. The details of this water-based solution are outlined in Table 7 below.
TABLE 7
Liquid Component of Bone Cement
Chemical
Quantity/
Name
Chemical Formula
Mw
liter
Molarity
Di-Sodium
HNa 2 O 4 P
141.96
22.8 g/l
0.1606 M
Hydrogen
grams
Phosphate
Anhydrous
Sodium
H 2 NaO 4 P•H 2 O
137.99
45.5 g/l
0.3297 M
Dihydrogen
grams
Phosphate
Monohydrate
Tri-sodium
C 6 H 5 Na 3 O 7 •2H 2 O
294.10
147.1 g/l
0.500 M
Citrate
grams
D. Mixing of the Powdered Components with the Liquid Component to Produce the Final Cement
For the final cement usage, add the DCPD with the TTCP in an equimolar ratio (i.e. DCPD-to-TTCP ratio of 31.97:68.03). This powder mixture was blended to ensure the formation of a homogeneous mixture. Then the liquid component was added using a liquid-to-powder ratio of 0.32 to form a settable final product.
EXAMPLE 2
A. Production of Dicalcium Phosphate Dihydrous with 60 ppm of Magnesium
(1) 30% Phosphoric Acid Solution Preparation with 60 ppm Magnesium Addition
To make the required 30% concentration of orthophosphoric acid (H 3 PO 4 ), in a 5 ltr stainless beaker, 261±2 mls of 85% orthophosphoric acid was added to 737±2 mls of deionized water and the beaker was placed on top of a hot plate set to 47° C. Then the temperature probe was placed in the beaker to measure the temperature of the acid solution and the hot plate was turned on to heat the solution to 47° C. The solution was then stirred at a speed of 200±10 rpm to ensure that the probe was measuring a true representation of the beaker content. While the acid solution was being heated to 47° C., 0.0620 grams of magnesium oxide (MgO) (equivalent to about 60 ppm magnesium content or about 0.0085% based on the weight of the DCPD) was added to the solution. Then the pH probes and temperature probes were calibrated and put in to the acid solution.
(2) Preparation of Calcium Carbonate Solution
0.45 kg of calcium carbonate (CaCO 3 ) was added into a 5 kg stainless steel beaker and 1 ltr of deionized water was added to the beaker. The beaker was then placed on top of a hot plate which was set to 42° C. Then the temperature probe was placed into the calcium carbonate suspension and the hot plate was turned on. The calcium carbonate suspension was then stirred at a speed of 575+/−50 rpm to ensure that the probe was measuring a true representation of the beaker content.
(3) Wet Chemical Precipitation
Once the magnesium spiked orthophosphoric acid reached the temperature of 47° C. and calcium carbonate suspension reached the temperature of 42° C., Watson-Marlow's Model 323u/D peristaltic system was set up to feed the carbonate suspension into the magnesium spiked orthophosphoric acid at a feed rate of 48+/−2 ml/min. Then the pH probe was activated in order to obtain the temperature/pH/time data at the start. Then the carbonate suspension was fed into the acid solution. Once the pH of the acid solution reached a pH of ˜3.6, the feed rate of the carbonate was stopped and the pH of the solution was monitored. The pH data from the beginning till the end of the carbonate feed was recorded. Once the pH reached 5.00, the final temperature/pH/time data for the precipitate was taken and all the temperature and pH probes as well as the peristaltic tube from the solution were removed. The reaction of magnesium, orthophophoric acid and calcium carbonate produced the stabilized DCPD precipitate.
(4) Precipitate Rinsing
A Whatman #5 filter paper (2.5 μm pore size) was placed into each Buckner funnel attached to a Buckner flask. Five (5) Buckner funnels attached to Buckner flasks were needed per precipitation run. Then, the precipitate solution (approximately 300 ml) was poured into each Buckner funnel attached to a Buckner flask and then a vacuum pump was turned on. The pump drew a vacuum and caused the water to be removed from the precipitate while the filter paper kept the precipitate in the Buckner funnel. After a minimum of two minutes of suction, each Buckner funnel was filled to the rim with deionized water (approx. 200-300 ml) in order to rinse any excess reactants from the precipitate. The precipitate was left under the vacuum for a minimum time of 5 minutes in order to ensure removal of any excessive free moisture.
(5) Freeze Drying
Next, a maximum of 300 grams (approximately half a precipitate production yield) was placed per freeze-drying tray in a manner ensuring that the precipitate is spread out evenly on the tray. The filled trays were then placed into Biopharma Process System's Model VirTis Genesis 25 Super ES freeze dryer. Each tray contained a temperature probe in order to monitor the precipitate temperature/moisture level during drying. Then the freeze dryer cycle was set to the program listed below and was turned on.
TABLE 8
Freeze Drying Recipe For DCPD
Step
Temperature (° C.)
Time (minutes)
Vacuum (mTorr)
*R
−15
1
100
**H
−15
120
100
R
−5
120
200
H
−5
240
200
R
0
120
1000
H
0
600
1000
R
10
60
1000
H
10
30
1000
R
20
60
1000
H
20
30
1000
*R = Ramp section of the freeze drying cycle
**H = Hold section of the freeze drying cycle
Once the precipitate has been dried using the freeze-drying cycle listed in Table 8, the precipitate required milling in order to reduce the average particle size so as to improve the final cement handling and setting properties. This milling is performed using Glen Creston's Model BM-6 roller ball-mill.
(6) Ball-Milling
3000+/−30 grams of alumina milling media (13.0 mm diameter×13.2 mm height) was placed into each ball-mill jar. Then, 500+/−25 grams of the dried DCPD precipitates were added into each ball-mill jar and were placed on the ball-mill rollers. The ball-mill was set to 180 rpm and a mill time of 32 minutes, and was turned on.
The ball-mill jar speed was monitored to ensure that it is rotating at 95 rpm. Once the 32 minutes of milling has elapsed, the milling media was separated from the milled powder by sieving through the 8 mm screen provided. The milled and sieved powders have a particle size within a range of about 0.4 to 200 μm, preferably about 35±20 μm, as measured by Beckman Coulter's Model LS 13320 Series particle size analyzer. The milled and sieved powders were then placed into the freeze-drying trays and the freeze-drying procedure as detailed in the previous section was repeated.
B. Production of Tetra Calcium Phosphate (TTCP)
(1) TTCP Cake Preparation
To form the preferred TTCP, the TTCP slurry mixture needs to comprise a 50% w/w solution of solid to liquid with the solid component comprising 60.15% dicalcium phosphate anhydrous (DCPA) and 39.85% CaCO 3 and the liquid component comprising purified water. To prepare a batch of TTCP “cakes” for sintering in the furnace, i.e., 3500 grams of TTCP cakes, 2105.25+/−0.5 grams of DCPA was accurately weighed out into a clean 5 liter Buckner flask. To this, 1394.75+/−0.5 grams of CaCO 3 were added. To this powder mixture, 3.5 liters of deionized water was added. Table 9 shows the specific amounts and percentages of these components.
TABLE 9
Raw Material Weights For The Production Of TTCP Cakes
Material
Weight (g)
Ratio (%)
CaCO 3
1394.75 ± 1
39.85
DCPA
2105.25 ± 1
60.15
Water
3500.00 ± 10
100
The Buckner flask was then sealed with appropriate rubber bung and nozzle attachments. The Buckner flask was placed in Glen Creston Ltd's Model T10-B turbular mixer for 25 minutes for homogenous mixing. Table 10 shows the turbular blending parameters.
TABLE 10
Turbular Parameters For Blending Of TTCP Raw Materials
Parameter
Setting
Speed (rpm)
44 ± 4
Time (mins)
25
Buckner Flask Volume (%)
90
While the Buckner flask was mixing, the appropriate vacuum tubing to a four-point manifold was connected: one end was attached to the vacuum pump, the other four points were attached to the nozzle attachments on four Buckner flasks. A 9 cm diameter polypropylene Buckner funnel was assembled onto each of the four Buckner flasks, respectively, and Whatman grade 5 filter paper was placed into each Buckner funnel. The blended DCPA/CaCO 3 /water mixture was removed from the turbular mixer, and the rubber bung was removed. Then, each polypropylene Buckner funnel was completely filled with the TTCP slurry. The TTCP slurry was vacuum dried using the vacuum pump, and the vacuum was drawn for a minimum of 5 minutes until the cakes formed solid top surfaces. Further vacuum drying could be used if required to form solid cakes. Once the cakes were formed, the vacuum on the Buckner flasks was released. Each funnel was removed from the flask and the inverted funnel was gently tapped to remove the cake. Each funnel produced a cake of approximately 300 grams.
Then the spent filter paper was removed, the funnel was washed out with purified water and a fresh filter paper was placed in the funnel. The above steps were repeated until all the slurry solution is in a cake form. The TTCP slurry was hand mixed every four to five cake preparations to ensure homogeneity. If upon removal from the funnel, the cake was broken or has a rough surface, the deionized water was sprayed onto the surface to bind loose fragments together. Any loose remaining fragments were reintroduced to the slurry mixture to form new cakes.
(2) Sintering
All cakes were stacked onto a stainless steel tray and dried for two hours at 200° C. in Lenton's Model AWF 12/42 muffle furnace to drive off excess moisture prior to sintering. The TTCP cakes were now ready to be sintered using the sintering program detailed in Table 11.
TABLE 11
Sintering Parameters For Firing Of TTCP Cakes
Step
Temperature (° C.)
Time (minutes)
Ramp Rate (° C./min)
Ramp
800
100
8
Dwell
800
≧120
n/a
Ramp
1550
94
8
Dwell
1570
780
n/a
Cool
800
≦10
75
Cool
20
15
52
The sintered cakes were transferred to a vacuum Buckner flask before the temperature dropped below 150° C. unless the material was to be crushed and milled immediately.
(3) Jaw Crushing
TTCP was processed through Glen Creston's jaw crusher to reduce the granules to a manageable size, preferably in the range of about 2.5 to 7.5 mm prior to processing through the co-mill. The sintered TTCP cakes were manually broken using a mortar and pestle to particle sizes of approximately one inch in diameter before loading into the jaw crusher. In this instance, the jaw crusher gap was set to 7.5 mm.
(4) Co-Milling of TTCP Granules
TTCP was processed through Quadro Inc.'s co-mill (Model Quadro Comil 197) to reduce the material to the final particle size. The mill speed was set to 5500+/−300 rpm. The impeller gap was set to 0.375″ using stainless steel washers. To co-mill the TTCP powder, the jaw-crushed TTCP powders were slowly fed into the co-mill at a rate of approximately 700 grams/min, ensuring that the co-mill did not become clogged with excess powder. (See Table 12 for co-milling parameters.)
TABLE 12 Parameters For Co-Milling The Jaw-Crushed Sintered TTCP Cakes Parameter Setting Screen No. 0.024″ Impeller speed 5500 rpm
(5) Ball-Milling
Glen Creston Ltd's Model BM-6 roller ball mill was used to ball-mill the sintered, jaw crushed and co-milled TTCP. The ball milling parameters for the dry milling of the sintered, jaw crushed and co-milled TTCP are listed in Table 13. For the dry milling of the TTCP, a total of 3000+/−50 grams of alumina milling media (13.0 mm diameter×13.2 mm height) was weighed into an alumina ball-milling jar, to which 900 grams of the TTCP was added. The ball mill parameters are outlined in Table 13 below.
TABLE 13
Milling Parameters For The Dry Ball-Milling Of TTCP
TTCP Ball Mill Parameters
Speed (rpm)
95
Time (mins)
430
Media fill weight (grams)
3000 +/− 50
TTCP weight (grams)
900
C. Production of Water-Based Solution of Sodium Phosphate and Trisodium Citrate
Into one liter of high purity water, 22.8 grams of di-sodium hydrogen phosphate anhydrous, 45.5 grams of sodium dihydrogen phosphate monohydrate and 147.1 grams of tri-sodium citrate were added and stirred until they were completely dissolved. The details of this water-based solution are outlined in Table 14 below.
TABLE 14
Liquid Component of Bone Cement
Chemical
Quantity/
Name
Chemical Formula
Mw
liter
Molarity
Di-Sodium
HNa 2 O 4 P
141.96
22.8 g/l
0.1606 M
Hydrogen
grams
Phosphate
Anhydrous
Sodium
H 2 NaO 4 P•H 2 O
137.99
45.5 g/l
0.3297 M
Dihydrogen
grams
Phosphate
Monohydrate
Tri-sodium
C 6 H 5 Na 3 O 7 •2H 2 O
294.10
147.1 g/l
0.500 M
Citrate
grams
D. Mixing of the Powdered Components with the Liquid Component to Produce the Final Cement
For the final cement usage, add the DCPD with the TTCP in an equimolar ratio (i.e. DCPD-to-TTCP ratio of 31.97:68.03). This powder mixture was blended to ensure the formation of a homogeneous mixture. Then the liquid component was added using a liquid-to-powder ratio of 0.32 to form a settable final product.
The DCPD powders produced as described in Examples 1 and 2 were analyzed for long-term stability using an X-ray diffractometer. First, as shown in FIGS. 1 and 3 , the X-ray powder diffraction patterns of the initial dry DCPD powders of Example 1 and Example 2 were collected using Rigaku's X-ray diffractometer.
Then, 5 grams of DCPD powders were packaged in a topaz bowl and heat-sealed with a breathable Tyvek lid. This bowl is then placed in a foil pouch with 10 grams of silicon desiccant. The foil pouch is then heat-sealed. The sealed foil pouch is then placed in a climatic oven set at 50° C. and aged for a set period of time. It has been determined that storage under these conditions for 52 days is equivalent to 1 year real time ageing.
The DCPD powders of Example 1 were stored in a climatic oven set at 50° C. for 77 days, and the DCPD powders of Example 2 were stored in a climatic oven set at 50° C. for 91 days for accelerated ageing tests.
After the exposure in the accelerated ageing test conditions, the X-ray powder diffraction patterns of the DCPD powders of Example 1 and Example 2 were collected again using the same Rigaku's X-ray diffractometer. As shown in FIGS. 2 and 4 , said stabilized dicalcium phosphate dihydrous containing magnesium exhibited characteristic x-ray diffraction peaks of dicalcium phosphate dihydrous. More specifically, after the exposure in the accelerated ageing test conditions as mentioned above, the X-ray powder diffraction patterns of the DCPD powders of Example 1 and Example 2, said stabilized DCPD powders exhibited x-ray diffraction peaks at 11.605, 20,787, 23.391, 26.5, 29.16, 30.484, 31.249, 31.936, 33.538, 34.062, 35.45, 36.34 and 39.67±0.2 degrees two-theta after 1 year of storage at 25° C. in a sealed container or after an accelerated ageing test of 52 days at 50° C. in a sealed container.
The bone cements produced as described in Examples 1 and 2 were also tested for penetration resistance after the accelerated ageing tests. The preferred penetration resistance requirements for the present invention are ≧1000 psi after 5 minutes from being mixed and a resistance of≧3500 psi after 10 minutes from being mixed. Tables 15 and 16 show the results of the penetration resistance tests using the bone cements produced according to Examples 1 and 2 above.
TABLE 15
Penetration Resistance Test Results
Bone Cement Containing DCPD With
40 ppm Of Magnesium (Example 1)
Sample Number
Results
1
3414 psi @ 5 min
7227 psi @ 10 min
2
3723 psi @ 5 min
6843 psi @ 10 min
3
2441 psi @ 5 min
7444 psi @ 10 min
4
2615 psi @ 5 min
6606 psi @ 10 min
5
2193 psi @ 5 min
6243 psi @ 10 min
6
2341 psi @ 5 min
7153 psi @ 10 min
Sample Average
2788 psi @ 5 min
6919 psi @ 10 min
TABLE 16
Penetration Resistance Test Results
Bone Cement Containing DCPD With
60 ppm Of Magnesium (Example 2)
Sample Number
Results
1
1947 psi @ 5 min
4668 psi @ 10 min
2
1675 psi @ 5 min
3947 psi @ 10 min
3
1649 psi @ 5 min
4567 psi @ 10 min
4
2371 psi @ 5 min
3047 psi @ 10 min
5
2096 psi @ 5 min
5872 psi @ 10 min
6
2903 psi @ 5 min
5483 psi @ 10 min
Sample Average
2106 psi @ 5 min
4930 psi @ 10 min
As these and other variations and combinations of the features discussed above can be utilized without departing from the present invention as defined by the claims, the foregoing description of the preferred embodiments should be taken by way of illustration rather than by way of limitation of the invention as defined by the claims.
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The invention is related to a rapid setting calcium phosphate cement comprising a powdered first component comprising stabilized dicalcium phosphate dihydrous containing from about 10 ppm to about 60 ppm of magnesium, a powdered second component comprising a calcium phosphate mineral other than said stabilized dicalcium phosphate dihydrous, and a liquid third component comprising water.
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[0001] This application is related to U.S. patent application Ser. No. 10/265,287 entitled “Anterior Sternal Thoraco-Lumbosacral Spinal Orthosis,” which is incorporated herein by reference in its entirety.
[0002] An exemplary aspect of this invention relates to spinal orthosis. More particularly, an exemplary aspect of the invention relates to spinal orthoses and a spring biased hinge mechanism that is capable of providing rigid frame spinal bracing for musculoskeletal injury, disease, or the like, that occurs, for example, in the thoracic, lumbar and sacral spinal regions.
[0003] The anatomy of the spine is usually divided into four major sections: the cervical, thoracic, the lumbar and the sacral. Each section is made up of individual bones called vertebrae with there being 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae. In order to relieve pain that can sometimes be associated with back injuries, it may be necessary to temporarily hyperextend the spine by using some type of orthosis.
[0004] According to an exemplary embodiment of the present invention, a spinal orthosis features a semi-resilient material, such as either a homogenous material or a laminate, the laminate having at least one of a shell and a liner, the shell at least partially having at least one layer, for example, a clothing contact surface material, a core, a stiffener and, for example, a strengthening material. The liner can have at least one layer, for example, at least one of a resilient cushion and a dermal contact surface layer.
[0005] A second exemplary embodiment relates to a spinal orthosis featuring a semi-rigid semi-resilient material that can be, for example, a homogenous material or a laminate, with the laminate having at least one of a shell and a liner. The shell can, for example, at least partially have at least one layer of at least one of a clothing contact surface material, a core, a stiffener and a strengthening material. The liner can at least partially include at least one layer of at least of a one resilient cushion and a dermal contact surface layer.
[0006] A third exemplary embodiment includes a spring biased hinge attached to an anterior surface of the orthosis, the spring biased hinge biasing a sternal portion.
[0007] The clothing contact surface can be made of any one or more of a plastic, a metal, an alloy, a cloth, leather, a rubber, a polyethylene, a polypropylene, a polyvinylchloride, a polybuterate, a polystyrene, a polycarbonate, an aluminum, or the like.
[0008] The core can be, for example, made from one or more of a plastic, a metal, an alloy, a cloth, leather, a rubber, a polyethylene, a polypropylene, a polyvinylchloride, a polybuterate, a polystyrene, a polycarbonate, an aluminum, or the like.
[0009] The strengthening material can be made from one or more of a plastic, a metal, an alloy, carbon fibers, glass fibers, plastic fibers, a cloth, leather, a rubber, a polyethylene, a polypropylene, a polyvinylchloride, a polybuterate, a polystyrene, a polycarbonate, an aluminum, or the like.
[0010] The sternal pressure base, hinge and sternal pressure bar can be made from one or more of a plastic, a metal, an alloy, carbon fiber, fiberglass, an aluminum, or the like.
[0011] The stiffener can be, for example, made from one or more of a plastic, a metal, an alloy, a cloth, leather, a rubber, a polyethylene, a polypropylene, a polyvinylchloride, a polybuterate, a polystyrene, a polycarbonate, an aluminum, or the like.
[0012] The resilient cushion can be, for example, made from any one or more of a foam, a plastic foam, a cloth, leather, a rubber foam, a polyethylene foam, a polypropylene foam, a polyvinylchloride foam, a polybuterate foam, or the like.
[0013] The dermal contact surface can be made from any one or more of a plastic, a cloth, leather, a rubber, a polyethylene, a polypropylene, a polyvinylchloride, a polybuterate, a polystyrene, a polycarbonate, or the like, or some combination thereof.
[0014] An exemplary aspect of the invention features a spinal orthosis having an overlap to include at least one inner flap and at least one outer flap, with both the inner and the outer flaps extending in an essentially equivalent distance past a sagittal anterior-posterior midplane. A sternal pad assembly attaches to at least one of the outer flap and inner flap.
[0015] In accordance with another exemplary embodiment, a spinal orthosis features a chest module, such as a sternal plate, or a bridged pectoral pad set, wherein the chest module is at least partially supported by a hinge having an axis of motion perpendicular to a sagittal anterior-posterior midplane.
[0016] Another exemplary aspect of the invention relates to a spinal orthoses having a chest module being either a sternal plate or a bridged pectoral pad set. The chest module attaches via a hinge having an axis of motion perpendicular to the sagittal anterior-posterior midplane, collectively all the axes of motion defining a compound hinge, the compound hinge including a resilient element where the resilient element urges the at least one of the module attachment and the chest plate attachment in a posterior direction against a posterior pressure directing anchor point.
[0017] These and other aspects of the invention will be apparent from the following detailed discussion of the embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is in perspective view illustrating an exemplary embodiment of the present invention;
[0019] FIG. 2 is an exploded view of the spring biased hinge according to this invention;
[0020] FIG. 3 illustrates a cross-section of the spring biased hinge in an unbiased position;
[0021] FIG. 4 illustrates a cross-section of the spring biased hinge in a biased position;
[0022] FIG. 5 is an environmental view of the orthosis according to this invention; and
[0023] FIG. 6 is a second environmental view of the orthosis according to this invention.
DETAILED DESCRIPTION
[0024] FIG. 1 illustrates an exemplary embodiment of the orthosis module 100 . The orthosis module 100 comprises a torso support portion 101 , a sternal plate 102 , a sternal pressure base 105 , a spring biased hinge 200 , a sternal pressure bar 108 , one or more straps 110 , and one or more adjustable straps 104 with corresponding strap loops 106 .
[0025] While the torso support portion 101 of the orthosis module 100 that comes into contact and surrounds the torso of the patient as illustrated in FIG. 1 is shown as a substantially unitary structure, it should be appreciated that the torso support portion 101 could comprise multiple sections that are held together by a fastening system, or in general be of any shape or configuration that provides spinal orthosis.
[0026] For example, by utilizing the spring biased hinge, and adhering to basic biomechanical principles, the operation of the orthotic module can be expanded to any specific orthotic function. For example, use is not limited to spinal orthosis. The spring biased hinge and appropriate orthotic support could also be used in upper limb (hand wrist elbow, forearm) bracing and rehabilitation. For example, through the addition of uprights and cuffs with, for example, hook and loop closures, such as Velcro®, the spring biased hinge could be used to assist in reducing flexion or extension contractures at the elbow. The hinge can also be placed proximal to the volar surface, and by adding a distal opponens and a proximal forearm cuff, forces to resist palmarflexion or promote palmarflexion strengthening may be performed by patients.
[0027] The spring biased hinge and appropriate body brace could also be modified and placed anteriorly with a clip or clasp on one end and a calf cuff and upright on the other end of the hinge and be used in dorsiflexion and plantarflexion strengthening exercises. In general, the spring biased hinge and accompanying body braces/supports can be used in any application to include, for example, orthotic, orthopedic and rehabilitation of patients.
[0028] The exemplary orthosis module 100 in FIG. 1 wraps around a patient and forms an overlap 107 at an anterior face of the orthosis module 100 . The orthosis module 100 can, for example as discussed above, be constructed of a semi-rigid contortable plastic material with, for example, a resilient lining. The overlap 107 in the orthosis module 100 allows adjustment to varying levels of tightness around the patient by the adjusting mechanism comprising the adjustable straps 104 and corresponding strap loops 106 .
[0029] For example, the adjusting mechanism can comprise multiple adjustment straps 104 that attached to the orthosis module 100 on laterally opposite sides of the overlap 107 with one end of each adjustment strap 104 being affixed to the orthosis module 100 and on the other end threaded through a strap loop 106 and folded back onto itself and fixed, for example, through the use of a hook and loop fastening system. The adjustment straps 104 can, for example, alternate in different directions with one end of a first adjustment strap fixed to a first side of the orthosis module and the accompanying strap loop on the opposite side, with the next strap being fixed to the opposite side of the orthosis module 100 , and the strap loop on the opposite side as illustrated in exemplary FIG. 1 . The number of straps is not limited to three as illustrated, but rather can be varied, based on, for example, the size of the orthosis module, the amount of tightness required, and the like. Likewise, the adjusting mechanism need not be limited to straps and strap loops but could also be made from any one or more of laces, belts and buckles, and the like.
[0030] Furthermore, additional straps can be located on any portion of the orthosis module, such as straps 110 , that can be further used to, for example, tighten a portion of the orthosis module 100 , maintain the position of the orthosis module 100 on a patient, and the like. For example, as illustrated in FIG. 1 , the straps 110 can be used in an over-the-shoulder type arrangement and fixed to the anterior face of the orthosis module by a fastening mechanism (not shown).
[0031] Also attached to the anterior face of the orthosis module 100 is a sternal pressure base 105 that is affixed, for example, to the anterior face of the orthosis module 100 where the overlap 107 occurs. The sternal pressure base 105 can be attached to the orthosis module 100 by many means including, but not limited to, bolts, screws, rivets, adhesives, clamps, molded interlocks, and the like. Furthermore, it should be appreciated that the sternal pressure base 105 could be integrally formed into the orthosis module 100 and can be fixed to or integrated into either the inner or outer flap.
[0032] The walls of the orthosis module 100 are contoured to exert compression from all sides by creating an increased hydraulic rigidity in a patient's abdominal section. This abdominal hydraulic rigidity increases the support between the pelvis and the thorax and provides corrective forces. The corrective forces are arranged in a 3-point pressure system, wherein the anterior portion of the orthosis module 100 provides a posteriorly directed force, the sternal plate 102 provides a second posteriorly directed force, and a posterior section of the orthosis module provides an anteriorly directed force.
[0033] Attached to the upper end of the sternal pressure base 105 is a spring biased hinge 200 which is also connected to the sternal plate 102 . As described in greater detail hereinafter, the spring biased hinge 200 is capable of providing a posteriorly directed force due to the spring biased feature as discussed hereinafter. The spring biased hinge 200 is connected to the sternal pressure base 105 and sternal pressure bar 108 by, for example, bolts, screws, rivets, adhesives, clamps, molded interlocks, a friction fit, a mechanical fit, or any other fastening means and/or arrangement that is capable of holding the various components together.
[0034] While the exemplary embodiment illustrated in FIG. 1 shows the sternal plate 102 as a single component, such as a pad, it is to be appreciated in the sternal plate 102 can be configured, for example, in a wide variety of configurations including but not limited to a plurality of pads. Likewise the shape of the sternal plate(s) can be altered into any shape, including, but not limited to, a circle, oval, square, kidney-shape, or the like. Furthermore, the sternal plate 102 can include padding and is fixed to the external pressure bar by fastening means, such as those discussed in relation to the external pressure base.
[0035] FIG. 2 illustrates in greater detail an exploded view of the hinge 200 . In particular, the exemplary spring biased hinge 200 comprises a sternal pressure base portion 210 , a sternal pressure bar portion 220 , a hinge pin 230 , a nut 240 , a plurality of, for example, set screws 250 , a spring 260 , a ball bearing 270 , and a tension adjustment mechanism 280 . As previously discussed, the sternal pressure base 105 can fit into slot 205 of the sternal pressure base portion 210 and secured, for example, by setscrews 250 . In a similar manner, the sternal pressure bar 106 can be inserted into slot 215 and secured by setscrews 250 . The spring biased hinge 200 , and in particular the external pressure bar portion 220 and external pressure base portion 210 are hingedly connected by means of a hinge pin 230 which is secured by nut the 240 . The spring biased hinged 200 is fixed to the external pressure base 105 in a manner such that the sternal plate 102 opens in a posteriorly directed manner. This spring biased hinge 200 when closed, allows the sternal plate 102 to be substantially parallel to the chest of the patient.
[0036] The tension adjusting mechanism 280 , in cooperation with the spring 260 and ball bearing 270 , provides a bias on the hinge which produces a posteriorly directed force that is applied by the sternal plate 102 to the chest of the patient. As, for example, the tension adjusting mechanism 280 is screwed into the corresponding threaded receiving portion 285 , the spring 260 is placed under greater compressive force which presses the ball bearing 270 against a surface of the sternal pressure bar portion 220 thereby providing the posteriorly directed force.
[0037] As illustrated in greater detail in FIG. 3 , the spring biased hinge 200 is illustrated in a closed position. In the closed position, the spring biased hinge is held in a substantially linear orientation by means of bump stops 225 and 235 . It should be appreciated that the thickness of the bump stops 225 and 235 can be modified such that, for example, the spring biased hinge, when closed, can be substantially linear, or, for example, adjusted such that the sternal plate 102 is angled slightly toward or away from the patient as appropriate.
[0038] As illustrated in FIG. 4 , the tension adjusting mechanism 280 has been “tightened” such as to create a greater compressive force on the spring 260 thereby forcing the ball bearing 270 to press against a surface of the sternal pressure bar portion 220 thereby creating the posteriorly directed force. The tightening, in turn, presses the sternal plate against the chest of a patient. As the tension adjusting mechanism 280 is further screwed into the receiving portion 285 , the posteriorly directed force increases.
[0039] As illustrated in the figures, while a coil spring is used is to create the posteriorly directed force, it should be appreciated that other spring mechanisms, such as a flat spring, or the like, could be used with equal success. Furthermore, a “mouse-trap” type spring arrangement could be utilized, for example, wherein the coil portion of the mouse trap type spring surrounds the hinge pin 230 . The spring could then be tensioned by a tensioning mechanism (not shown) that, for example, adjusts a non-helix portion of the spring, thus increasing the posteriorly directed force in a similar manner.
[0040] The spring tension adjusting mechanism is not be limited to the spring and tensioning adjusting screw as shown, but could also include, for example, a pneumatic or hydraulically based system, with, for example, an exterior pump that allows for the posteriorly directed force to be adjusted. More particularly, a cylinder and piston type arrangement could be used in place of the tension adjusting mechanism spring and ball bearing whereby a material, such as a fluid is injected into the cylinder which thereby extends a piston that presses against the surface of the sternal pressure bar 230 and increases the posteriorly directed force.
[0041] It should further be appreciated that the bias mechanism can be interchanged based on, for example, the intended patient use. For example, for use with a child, the spring 260 could be switched for a spring with lesser bias. Alternatively, for example, for a large patient, a larger spring could be used to provide more substantial posteriorly directed force.
[0042] FIGS. 5 and 6 illustrate environmental views of the orthosis module 100 . In particular, FIG. 5 illustrates the orthosis module 100 where the sternal plate 102 is resting against the patient's chest and the spring biased hinge 200 is in the closed position. FIG. 6 illustrates the orthosis module 100 with the spring biased hinge 200 providing a posteriorly directed force which is thereby pressing the sternal plate 102 against the chest of the patient thereby keeping the patient in a more erect position.
[0043] It is, therefore, apparent that there is provided, in accordance with the present invention, an orthosis system. While this invention has been described in conjunction with a number of embodiments, many alternatives, modifications, and variations would be apparent to those of ordinary skill in the applicable arts. Accordingly, all alternatives, modifications, equivalents and variations are intended to be included within the spirit and scope of this invention.
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An anterior opening spinal orthosis features a sternal plate and/or a bridged pectoral pad set. The sternal plate and/or a bridged pectoral pad set is at least partially supported by a spring biased hinge having an axis of motion perpendicular to a sagittal anterior-posterior midplane. The spring biased hinge is capable of providing a posteriorly directed force against the chest of a patient.
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BACKGROUND OF THE INVENTION
This invention relates to a brush section for an electric toothbrush, with a handle section connectible with the brush section, a bristle carrier of an in particular circular disk shaped configuration which is arranged at the end of the brush section remote from the handle section and has on its upper side bristle tufts disposed at least on one central ring and one outer ring, said bristle carrier being mounted on the brush section so as to be rotatable about an axis of rotation, in particular in an alternating oscillating fashion from a central position, and said axis of rotation being aligned angularly, in particular at right angles to a longitudinal center line of the brush section.
A brush section of this type for an electric toothbrush is known from International Patent Application WO 91/07116. In this specification, the bristles of the tufts disposed on the outer ring and the central ring of the bristle carrier are all of approximately equal length. This enables a user to clean uniformly in particular the tooth surfaces.
In a brush section for an electric toothbrush as disclosed in International Patent Application WO 94/21192, the bristles of the tufts disposed on the bristle carrier differ in length. In particular it is proposed in this specification that tufts comprised of longer bristles be arranged on a diameter within an outer ring. These longer bristle tufts thus enable the user to accomplish a better dental cleaning operation in particular on the interproximal spaces.
SUMMARY OF THE INVENTION
On the basis of the foregoing, it is an object of the present invention to provide a brush section for an electric toothbrush which enables a still further improved cleaning of the teeth, in particular of the interproximal spaces.
This object is accomplished in a brush section of the type initially referred to in that the outer ring is set with tufts of bristles of different lengths.
When tests were conducted, this arrangement of the longer bristle tufts in the outer ring of the bristle carrier has proven to be particularly advantageous. With this arrangement, a particularly good interproximal cleaning operation can be accomplished. This is presumably so because during dental cleaning the shorter bristle tufts on the outer ring of the bristle carrier take support upon the tooth surface, thus enabling the longer bristle tufts on the outer ring to penetrate between the user's teeth completely. In this manner, the longer tufts on the outer ring produce a thorough cleaning action on the interproximal spaces, while at the same time the shorter bristle tufts on the outer ring clean the tooth surfaces uniformly.
In an advantageous further development of the present invention, fourteen bristle tufts are arranged on the outer ring, comprising a cluster of four adjacent short bristle tufts, a cluster of three adjacent long bristle tufts, a cluster of four adjacent short bristle tufts, and a cluster of three adjacent long bristle tufts. Each cluster of tufts thus fills a sector of the outer ring. In this manner, the long and the short bristle tufts are each disposed in diametrically opposed sectors of a circle. As a result, the long and the short bristle tufts are symmetrically disposed on the outer ring of the bristle carrier. This has proven to be a particularly advantageous arrangement for cleaning the interproximal spaces.
The reason for this is presumably that in dental cleaning the long bristle tufts provided in the two sectors are able to penetrate the interproximal spaces on either side of a neck for cleaning, while the shorter bristle tufts contribute to supporting the bristle carrier on the tooth surface and thus to the cleaning thereof.
In an advantageous aspect of the present invention, in the central position of the bristle carrier the sectors with the long bristle tufts are arranged along the longitudinal center line, and the sectors with the short bristle tufts are arranged transversely to the longitudinal center line. This has proven to be particularly advantageous for the manipulation of the electric toothbrush. When a user holds the electric toothbrush approximately parallel to his upper or lower jaw for cleaning his teeth, the long bristle tufts are able to penetrate and clean the interproximal spaces.
In an advantageous further development of the present invention, the bristle tufts or the clusters of bristle tufts of different length each differ in color. Because of the severer load placed upon them, it is particularly suitable to make provision for the long bristle tufts to be comprised of color indicator bristles, in particular of green or blue bristles. This makes it easy for the user to make a visual distinction between long and short bristle tufts. The advantage thereby achieved is that it is by reason of this visual impression alone that the user aligns the electric toothbrush properly, thereby enabling the described improved cleaning action to be accomplished by the tufts with the longer bristles without any further action being necessary.
In an advantageous further development of the present invention, the tufts on the central ring are comprised of bristles of a substantially uniform length corresponding approximately to the bristle length of the short bristle tufts on the outer ring. This has the advantage that it is not only the short bristle tufts on the outer ring that are used for bearing against the tooth surface as explained, but also the equally short bristle tufts on the central ring. Particularly suitably, the adjacent tufts on the central ring lying radially inwardly relative to the long bristle tufts on the outer ring are comprised of color indicator bristles, in particular of green or blue bristles. The colored tufts on the central ring and on the outer ring thereby form diametrically opposed wedges. This further enhances the described visual effect of an automatically correct alignment of the electric toothbrush by its user.
In an advantageous further development of the present invention, at least two short bristle tufts are provided in an inner zone of the bristle carrier, their arrangement being preferably at about right angles to the central position of the bristle carrier. These serve, as the short bristle tufts on the outer ring and the central ring, for further supporting the bristle carrier on the tooth surface.
Further features, advantages and application possibilities of the present invention will become apparent from the subsequent description of embodiments illustrated in more detail in the accompanying drawings. It will be understood that any single feature and any meaningful combination of single features described and/or represented by illustration form the subject matter of the present invention, irrespective of their summary in the claims and their back-reference.
BREIF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side view of an electric toothbrush;
FIG. 2 is a schematic top plan view of the bristles illustrating a first embodiment of a bristle carrier for the electric toothbrush of FIG. 1;
FIG. 3 is a schematic top plan view of the bristles illustrating a second embodiment of a bristle carrier for the electric toothbrush of FIG. 1;
FIG. 4 is a schematic top plan view of the bristles illustrating a third embodiment of a bristle carrier for the electric toothbrush of FIG. 1; and
FIG. 5 is a schematic top plan view of the bristles illustrating a fourth embodiment of a bristle carrier for the electric toothbrush of FIG. 1.
DETAILED DESCRIPTION
Referring now to FIG. 1 of the drawings, reference numeral 20 designates an electric toothbrush. The toothbrush 20 comprises handle section 22 and a brush section 24 adapted to be coupled therewith. The handle section 22 accommodates a secondary battery 26 or, alternatively, a primary battery, an electric motor 28, and a motion converting mechanism 30 for converting the continuous rotary motion of the electric motor 28 into an oscillatory motion. Provided on the outside of the handle section 22 is a switch 32 for activating the toothbrush 20. The brush section 24 includes a hollow mounting tube 36 receiving a shaft 34. The mounting tube 36 and the shaft 34 are connectible with the handle section 22 by a coupling means 40. Arranged at the end of the brush section 24 remote from the handle section 22 is a brush 38 with a bristle carrier 44 for receiving the bristles 48 or bristle tufts 46. A bevel gear arrangement 42 at the end of the shaft 34 sets the brush 38 in an oscillatory motion. The range of the angle swept by the bristle carrier 44 during this motion is preferably of the order of about ±35 degrees±5 degrees, with values in the range from ±10 degrees to ±100 degrees being however also possible. The oscillation frequency may be between 10 Hz and 100 Hz, approximately, preferably at 40 Hz to 70 Hz, approximately. The axis of rotation 50 of the bristle carrier 44 forms with the axis of rotation 52 of the shaft 34 an angle of about 90 degrees. The toothbrush of FIG. 1 is described in detail in applicant's International Patent Application WO 91/07116 which is hereby incorporated by express reference in the disclosure content of the present application.
FIGS. 2 to 5 illustrate four embodiments of bristle carriers 44 differing from each other in respect of arrangement, configuration and selection of the individual tufts 46 or bristles 48. Schematically indicated in FIGS. 2 to 5 are the mounting tube 36 as well as the axis of rotation 52 of the shaft 34, which axis is approximately coincident with the longitudinal center line of the mounting tube 36 and thus of the brush section 24. The axis of rotation 50 of the bristle carrier 44 is illustrated in the center of FIGS. 2 to 5. The bristle carrier 44 is configured essentially as a circular plate with a diameter of between 11 mm and 15 mm, approximately, preferably 12 mm, approximately. The tufts 46 or bristles 48 are arranged on the upper side of the bristle carrier 44 on a central ring 54, an outer ring 56 and in an inner zone 84 or inner ring 88, which are all approximately concentric with the axis of rotation 50 of the bristle carrier 44. The representations of FIGS. 2 to 5 illustrate the bristle carrier 44 in a central position 58, that is, the position occupied by the bristle carrier 44 as it passes through 0 degrees in its oscillatory rotational motion of ±35 degrees.
In the first embodiment of the bristle carrier of FIG. 2, a total of fourteen tufts 60, 62 are disposed on the outer ring 56, the central ring 54 having a total of ten tufts 72, 74, and the inner zone 84 having two tufts 86.
Adjacent tufts 60, 62 on the outer ring 56 are combined or subdivided into four clusters 64, 66. Cluster 64 is comprised of three tufts 60 disposed symmetrically to the longitudinal center line 52 and extending over a sector 68 with a central angle of 80 degrees, approximately. Cluster 64 exists twice, being symmetrically disposed on either side of an imaginary transverse axis extending through the axis of rotation 50 at right angles to the longitudinal center line 52. The sectors 68 associated with the two clusters 64 thus extend approximately longitudinally to the longitudinal center line 52. Cluster 66 is comprised of four tufts 62 arranged symmetrically to said transverse axis and extending over a sector 70 with a central angle of 100 degrees, approximately. Cluster 66 exists twice, being symmetrically disposed on either side of the longitudinal center line 52. The sectors 70 associated with the two clusters 66 thus extend approximately transversely to the longitudinal center line 52.
The tufts 60 of the clusters 64 on the outer ring 56 are provided with long bristles of a length of about 8.2 mm±about 0.2 mm to 0.5 mm. The tufts 62 of the clusters 66 on the outer ring 56 are provided with short bristles of a length of about 7.5 mm±about 0.1 to 0.5 mm. The long and the short bristles of the tufts 60, 62 of both clusters 64, 66 have a diameter of 6 mils, approximately. The tufts 60, 62 of both clusters 64, 66 are comprised of about 54±4 such bristles. The bore diameter of the mounting bores 82 for the tufts 60, 62 in the bristle carrier 44 is 1.5 mm, approximately.
The long bristles of the tufts 60 and the short bristles of the tufts 62 differ in color. This can be accomplished in particular by color indicator bristles, for example, by green or blue bristles of this type which are used as long bristles of the tufts 60.
The ten tufts 72, 74 on the central ring 54 are arranged such that each two tufts 74 are associated with the area of the two sectors 68, and each three tufts 72 are associated with the area of the two sectors 70. In this arrangement, the two tufts 74 on the central ring 54 lie radially inwardly relative to the adjacent long bristle tufts 60 on the outer ring 56.
The bristles of the tufts 72, 74 on the central ring 54 are all of a uniform length amounting approximately to the length of the short bristles of the tufts 62 on the outer ring 56, that is, about 7.5 mm±about 0.1 to 0.5 mm. The diameter of their bristles is 6 mils, approximately (1 mil=0.0254 mm). About 54÷4 such bristles combine to form one of the tufts 72, 74. The bore diameter of the mounting bores 82 for the tufts 72, 74 in the bristle carrier 44 is 1.5 mm, approximately.
The two tufts 74 arranged in the respective area of the two sectors 68 differ in color from the other tufts 62, 72. This can be accomplished by configuring the bristles of the tufts 74 in particular as color indicator bristles of a blue or green color, for example.
Of the two tufts 86 in the inner zone 84, one each is arranged in the area of the two sectors 70. The two tufts 86 are thus disposed at approximately right angles to the longitudinal center line 52 and thus approximately transversely to the central position 58. The bristles of the tufts 86 have a length of about 7.5 mm±0.1 to 0.5 mm, the bristle diameter is 6 mils, approximately. Each of the two tufts 86 is comprised of about 54±4 bristles. The bore diameter of the mounting bores 82 for the tufts 86 is 1.5 mm, approximately. The area of the two sectors 68 in the inner zone 84 is devoid of tufts.
Accordingly, in the first embodiment of FIG. 2 all tufts 62, 72, 86 in the area of the two sectors 70 comprise bristles of approximately like length and approximately like diameter. By contrast, in the area of the two sectors 68, the tufts 60 in the outer ring 56 have longer bristles than the tufts 74 in the central ring 54. Further, the tufts 60, 74 in the two sectors 68 differ in color from the tufts 62, 72, 86 in the two sectors 70.
In the second embodiment of FIG. 3, the sole difference to the first embodiment of FIG. 2 resides in that in the area of the two sectors 70 the tufts 62 on the outer ring 56 have bristles with a diameter greater than the bristles of the tufts 72, 86 on the central ring 54 and in the inner zone 84. As before, the bristles of the tufts 62 have a diameter of 6 mils, approximately, whereas the bristles of the tufts 72, 86 have a diameter of 5 mils, approximately. Thus, the bore diameter of the mounting bores 82 for the tufts 72, 86 is only 1.3 mm, approximately, and the bristles per tuft 72, 86 are in amount about 60±4. The length of the bristles of the tufts 62, 72, 86 remains unchanged at about 7.5 mm±0.1 mm to 0.5 mm.
In the third embodiment of FIG. 4, the sole difference to the first embodiment of FIG. 2 resides in that in the area of the two sectors 70 all of the tufts 62, 72, 86 on the outer ring 56, the central ring 54 and in the inner zone 84 have bristles of a diameter smaller than the bristles of the tufts 60 in the sectors 68. The bristles of the tufts 62, 72, 86 have a diameter of 5 mils, approximately. The bore diameter of the mounting bores 82 for the tufts 62, 72, 86 is 1.3 mm, approximately, and the bristles per tuft 62, 72, 86 are in amount about 60±4. The length of the bristles of the tufts 62, 72, 86 remains unchanged at about 7.5 mm±0.1 mm to 0.5 mm.
In the fourth embodiment of the bristle carrier 44 of FIG. 5, a total of sixteen tufts 60, 62 are arranged on the outer ring 56, a total of eight tufts 76 are on the central ring 54, and four or five tufts 86 are arranged in the inner zone 84.
The tufts 60, 62 on the outer ring 56 are alternating long and short bristle tufts. The long bristles of the tufts 60 have a length of about 8.0 mm±0.1 mm to 0.5 mm, while the short bristles of the tuft's 62 are about 7.0 mm±0.1 mm to 0.5 mm long. The bristle diameter of the long bristle tufts 60 is 6 mils, approximately, and of the short bristle tufts 5 mils, approximately. The long bristle tufts 60 are comprised of about 54±4 bristles each, and the short bristle tufts 62 have about 60±4 bristles per tuft 62. The bore diameter of the mounting bores 82 for the long bristle tufts 60 in the bristle carrier 44 is about 1.5 mm, and for the short bristle tufts 62 about 1.3 mm.
The tufts 76 on the central ring 54 have bristles of a uniform length corresponding to the length of the long bristle tufts 60 on the outer ring 56. Accordingly, the tufts 76 have bristles of a length of about 8.0 mm±0.1 mm with a bristle diameter of 6 mils, approximately, comprising about 54±4 bristles per tuft 76 and with a diameter of the mounting bores 82 for the tufts 76 in the bristle carrier 44 of about 1.5 mm.
The tufts 76 on the central ring 54 are laterally offset in a radial direction relative to the adjacent long bristle tufts 60 on the outer ring 56. The amount of offset 78, 80 is about 0.5 to 1.5 times the diameter of the mounting bores 82 for the tufts 76.
In the inner zone 84 is an inner ring 88 on which the four tufts 86 are circumferentially spaced apart by about 90 degrees. In addition, the four tufts 86 on the inner ring 88 are interplaced between the eight tufts 76 on the central ring 54.
A further possibility is to arrange a fifth tuft 86 in the center of the bristle carrier 44.
The tufts 86 have bristles of a uniform length corresponding approximately to the length of the short bristle tufts 62 on the outer ring 56. The length of the tufts 86 is thus about 7.0 mm±0.1 mm to 0.5 mm with a bristle- diameter of 5 mils, approximately. The number of bristles per tuft 86 is about 60±4 with a bore diameter of about 1.3 mm for the mounting bores 82 for the tufts 86.
The long bristle tufts 60 on the outer ring 56 and the long bristle tufts 76 on the central ring 54 differ in color from the remaining tufts 62 on the outer ring 56 and the tufts 86 in the inner zone 84. This can be accomplished by using in particular color indicator bristles, for example, blue or green bristles for the tufts 60, 76.
The embodiments of bristle carriers 44 described may be operated in a variety of ways in combination with the electric toothbrush 20 equally described. Thus it is possible for the bristle carrier 44 to be set in an alternating oscillatory motion about the axis of rotation 50 at a frequency of about 62 Hz±5 Hz. The angle of oscillation is about ±30 degrees±5 to 10 degrees, relative to the central position 58, the amplitude of the bristle deflection is about ±3 to 4 mm, and the bristle speed is approximately between 0.5 m/s and 2 m/s, preferably in the range from 0.9 m/s to 1.7 m/s, in particular at about 1.3 m/s. This possibility may be varied, for example, by operating the bristle carrier 44 at a frequency of about 47 Hz±5 Hz, resulting in a bristle speed of about 0.9 m/s, with the other values remaining unchanged. Another possibility involves setting the bristle carrier 44 in an alternating oscillatory motion about the axis of rotation 50 at a frequency of about 115 Hz±20 Hz. In this case, the oscillation angle is about ±11 degrees±3 degrees relative to the central position 58, the amplitude of the bristle deflection is about 0.5 mm to 2.5 mm, preferably about 1 mm to 1.2 mm, and the bristle speed is approximately in the range from 0.6 m/s to 1.2 m/s, preferably at about 0.9 m/s. Further possibilities of driving the bristle carrier 44 comprise any combination of the above values, and it will be understood that the above combinations of values are not intended to limit the wide variety of these combinations.
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The invention is directed to a brush section (24) for an electric toothbrush (20) in which a handle section (22) is connectible with the brush section (24). A bristle carrier (44) of a circular disk shaped configuration is arranged at the end of the brush section (24) remote from the handle section (22) and has on its upper side bristle tufts (46, 60, 62, 72, 74) disposed on one central ring (54) and one outer ring (56). The bristle carrier (44) is mounted on the brush section (24) so as to be rotatable about an axis of rotation (50) in an alternating oscillating fashion from a central position (58). The axis of rotation (50) is aligned at approximately right angles to a longitudinal center line (52) of the brush section (24). In use of the electric toothbrush (20), an improved cleaning action is accomplished in that the outer ring (56) of the bristle carrier (44) is set with tufts (60, 62) of bristles of different lengths.
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FIELD OF THE INVENTION
The present invention relates to the use, in a navigation device, of a method for making available driving lane recommendations for each driving direction relating to at least one curb or one segment of road and interlinked with one another. The present invention further relates to a system for implementing such a method.
BACKGROUND INFORMATION
In means of transportation such as motor vehicles, permanently installed navigation devices simply, quickly, and safely guide the driver of a means of transportation from the current location to a desired destination without the driver of the means of transportation first having to elaborately plan a route and obtain appropriate maps.
For this purpose, appropriate navigation data based on charts, maps, or street maps are available stored, for example, on CD-ROM (=Compact Disc-Read Only Memory) or on DVD (=Digital Versatile Disc). The navigation device uses GPS (=Global Positioning System), for example, in order to determine the current location and calculate the appropriate navigation instructions that lead to the predetermined destination. The navigation data, in this connection, preferably contains data on roads and paths for motor vehicles.
An important component of the above-mentioned basic function of a navigation device is the processing of the driving lanes on the roads, especially before, at, and after intersections. Driving lanes, in this case, are to be understood as the fanning out of the driving directions, in particular before an intersection, painted on the road.
The processing of such driving lanes, which may be found directly on the road surface or on signs installed above the roads such as in the form of sign bridges and/or electronic alternative-route indicators having directional symbols and/or distant destinations, will initially be required only at freeway interchanges, but later also at all other intersections having driving lanes.
In this context, it must be considered, however, that so far, in conventional navigation devices, the processing of linked consecutive driving lanes is still inadequate. The driver of the means of transportation is not provided with information by the navigation device enabling him to optimally navigate the means of transportation through street traffic, especially in the case of a rapid succession of multiple intersections or forks in the road.
SUMMARY OF THE INVENTION
Based on the above-mentioned disadvantages and shortcomings, the object of the present invention is to create a method as well as a system, of the type mentioned at the outset, which improve the quality of the driving instructions provided by a navigation device via optimized processing of driving lanes on roads, in particular at intersections.
According to the teaching of the present invention, all curbs of the respective lanes are therefore given attributes carrying certain information explained in more detail below. Inserting the driving lanes into the curbs is carried out according to a particularly inventive further development by attaching the driving lanes to the particular curbs as new attributes.
Independent of or in conjunction with this, the curbs should expediently only carry one lane situation in each driving direction, otherwise they should be divided. The information initially contains only one list of available lanes (=“lane list”) per driving direction, i.e., in digitization direction of the curb or counter to the digitization direction of the curb. The sequence of the elements of the lane list should in this connection expediently coincide with the sequence of the lanes on the street, and should be counted from the outer curb of the road.
According to an advantageous further development of the present invention, the information further contains the length on which the lanes are available starting from the particular end of the curb; this avoids partitions of the curb in an advantageous manner in case lanes are only available at the end of the curb.
Each element of the lane list preferably contains the directional symbol associated with it, as well as optional additional information on special uses and other restrictions such as reservation of the lane for buses, taxis, or the like. This may also include—in a manner essential to the present invention—information in each element of the lane list regarding whether or not the lane marker for two adjacent driving lanes, i.e., for the adjacent left-hand lane or the adjacent right-hand lane, may be crossed by the driver of the means of transportation.
A relevant component of the information may also be at least one intersection approaching in the driving direction which is reached via this lane. If a curb is referred to that also has lanes, reference may be made to one of these lanes if it is understood to be a continuation of the original lane.
According to an advantageous embodiment of the present invention, the curbs, reference having been made to themselves or to their lanes, are linked to the same intersection as the original curb, but do not have to be directly meshed with same, since the intersection may also be complex, i.e., it may not consist of only one node, but of multiple nodes. In this case, it cannot always be guaranteed that it is possible to follow the lanes within these complex intersections.
In connection with the practical implementation and the actual application possibilities of the present invention, attention must be paid to the fact that a situation-and/or time-dependent switching of the lanes must be expected, as happens with greater frequency today via electronic alternative-route indicators in light of increased traffic densities, especially in city traffic with access and exit roads or on freeways having emergency lanes. The design of the data, therefore, should expediently facilitate the representation of such a dependency accordingly.
Generally, in view of the present invention, the fact must be considered that the quality of the acquisition of lanes may not in some cases be as high as the quality of the attributes relevant for the route search (one-way streets, turning prohibitions and the like). This may possibly result in discrepancies between route search and navigation using driving lanes, i.e., there are driving lanes at an intersection, but it is not possible to find a driving lane corresponding to the calculated route. Construction sites or the like also come to mind in this regard, of course, which in most cases involve detours or at least shifting of lanes.
In an embodiment essential to the present invention, lane information may also be used to make a perspective representation of the intersection and/or street existing in reality more realistic. For this purpose, the described data model, implemented according to the present invention in terms of method as well as system, contains all relevant information.
According to the present invention, the possibility of at least one selected driving lane carrying distant-destination information must be considered, so that this information may be included for the purpose of creating directions for getting into the correct lane, regardless of where the actual destination is (—>navigation device: “Take the lane for Dortmund!”)
Regarding the requirements on raw data for the method and the system according to the present invention, the data for a meaningful use of driving lanes for navigating must be selected such that the following categories and parameters may be filled with (data) content:
number of driving lanes at the approaching end of the traveled curb; type of symbols (if any) with which the individual driving lanes are marked on the road or on signs; driving lanes that may be used, in other words those that are not bus or taxi lanes; adjacent driving lanes, between which it is permitted to switch; and driving lane/s that is/are to be used in order to reach the subsequent curb, calculated by the route search algorithm, and the correct driving lane for continuing the route.
In this connection, the present invention also extends to a starting point essential to the present invention, where driving lanes may be digitized as separate curbs. In this case, the route search algorithm would assume the task of selecting the correct driving lane. It must be noted, however, that, at least at the moment, there still exist various inherent inadequacies with a mode of this type such as a difficult-to-manage data quantity, a certain locating uncertainty, digitization only from aerial photos, as well as the need for frequent changes.
The present invention, finally, relates to a navigation device operating according to a method of the type described above and/or having at least one system of the type described above.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A schematically shows a navigational driving lane recommendation for the right-hand lane.
FIG. 1B schematically shows a navigational driving lane recommendation for the two center lanes.
FIG. 2A schematically shows a lane combination with exit lane.
FIG. 2B schematically shows a curb diagram assigned to the driving lane combination from FIG. 2A .
FIG. 2C schematically shows an alternative curb diagram assigned to the driving lane combination from FIG. 2A .
FIG. 3A schematically shows a basic driving lane combination with intersection.
FIG. 3B schematically shows a curb diagram assigned to the basic driving lane combination from FIG. 3A .
FIG. 4A schematically shows an expanded driving lane combination with two intersections.
FIG. 4B schematically shows a curb diagram assigned to the expanded driving lane combination from FIG. 4A .
FIG. 5A schematically shows a further driving lane combination with branching of two expressways.
FIG. 5B schematically shows a curb diagram assigned to the further driving lane combination from FIG. 5A .
FIG. 6 schematically shows an “entity relationship” model of the present invention; and
FIG. 7 schematically shows a structure diagram of the interlinked lists in the present invention.
DETAILED DESCRIPTION
In the method and system according to the present invention, the driver of a means of transportation is able to receive information, in addition to the usual driving instruction, via driving lane information before reaching a decision point regarding which of the available driving lanes is best taken in order to be able to easily follow this driving instruction (see FIG. 1A , according to which the driver of the means of transportation would have to pick the right-hand one of the three driving lanes).
In real street traffic situations, there may be multiple suitable driving lanes when choosing lanes (see FIG. 1B , according to which the driver of the means of transportation would have to pick the middle, i.e., one of the two center lanes). While it is relatively simple to graphically represent such a situation, which is a little more complex than the situation in FIG. 1A , the oral identification of multiple lanes is difficult, especially when more than three driving lanes are available.
The present invention provides a possible alternative embodiment where the graphical representation of the driving lanes on the display device or on the display of a navigation device should coincide as far as possible with what the driver of the means of transportation sees painted on the driving lane or marked on signs in front of him. The arrow symbols used there—if any—should be taken into consideration in the design of the graphics of the navigation device.
In this connection, a test should also be carried out to see whether the lane-changing instructions should replace or supplement the driving instructions at this location, and/or how the calculation of the driving instructions is affected by the presence of driving lanes.
In the driving lane recommendations according to FIGS. 1A or 1 B, the change in direction at the immediately following decision point determines the driving lane selection. Should multiple lanes be available in one direction (see FIG. 1B for the “straight-ahead” direction), the navigation device recommends both lanes equally.
There are, however, also complex driving lane combinations, where the most favorable driving lane may only be selected if the route is viewed across more than one intersection (see FIG. 4A ). In order to get from street A to street C in the extended driving lane combination according to FIG. 4A , the driver of the means of transportation on street A must take the center lane, then, on street B, the right-hand driving lane, in order to then be able to turn into street C. Should the driver of the means of transportation want to continue his journey on street E, the left-hand or center lane on street A would be available to him. Street D may only be reached if the left-hand driving lane on street A is used.
Such lane sequences are sometimes crucial for the driver of the means of transportation, i.e., if the driver of the means of transportation takes the incorrect lane—in other words the left-hand lane—on street A with the complex lane combination of FIG. 4A , he is subsequently not permitted to change lanes again and must continue his journey in departure from the planned route on street B or street D. But even if there is no such constraint and it is still permissible to change lanes, it is desirable to provide information on the most favorable lane in any case in order to minimize the number of lane change maneuvers that are often critical in city traffic.
For the concept described above it is basically not necessary to know whether the driving lanes have dotted or solid lane markers, i.e., whether or not a lane change is permitted. If the linking of the lanes at the intersections is correctly digitized, the described route search algorithm will—if at all—select a lane sequence that will not require lane changes at the particular curbs.
A correct interlinking of the driving lanes, however, is only possible if the number of lanes along each of the curbs does not change. This means that the curbs must be divided in places where the number of driving lanes changes. At freeway exits, where typically the number of driving lanes increases by an exit lane, a lane combination as shown in FIG. 2 results; here, the node or intersection point marked by a separate arrow in FIG. 2B only exists due to the change in the number of driving lanes.
Alternatively, the exit according to FIG. 2A may also be digitized using a different course of a curb. This is how the exit lane is regarded as a separate driving lane according to FIG. 2C . The method according to the present invention may be used regardless of whether the curb diagram according to FIG. 2B or the curb diagram according to FIG. 2C has been chosen.
Regarding the “weave lanes” (merge or exit lanes), it must be added in this connection that, while in the lane combination depicted in FIG. 2A part of the expressway is recorded as having three lanes, this change in the number of lanes may only result in a lane change instruction if the expressway is to be left at the exit. In order to safely recognize this situation, the right-hand lane should be marked as a weave lane here. Lane-related instructions are only issued here if the weave lane must actually also be used.
However, it is not always possible to follow the selected route without changing lanes. Using the branching of two expressways shown as an example in FIG. 5A (in FIGS. 5A and 5B only the driving direction from right to left is shown), some situational examples can be illustrated; here it also becomes clear that for a complete description of the lane situation, the permissibility of crossing the lane markers must be known (dotted line, solid line, or both).
Route A->C->D, Route A->C->E:
Before the solid lane marker begins, the driver of the means of transportation must be guided into the right-hand driving lane (->route A->C->D) or into the left-hand driving lane (->route A->C->E) while still on street A in order to be able to follow the particular route.
Route A->C->F:
On street A, the driver of the means of transportation must first be guided into the left-hand driving lane and then into one of the left-hand lanes of street C; in other words, a lane change on street C is thus unavoidable.
Route B->C->D, Route B->C->E:
These routes cannot be followed by the driver of the means of transportation without crossing solid lines; there is a contradiction between the digitization of the driving lanes and the “turn restrictions,” but an automatic check of the data for such inconsistencies is possible.
Route B->C->F:
On this route no lane change is necessary, regardless of which driving lane is entered, and since no decision must be made, a driving instruction is also superfluous.
As far as the concrete implementation of the method, as well as the system, according to the present invention regarding following the course of a lane along a route is concerned, the presented data model makes it possible to select and output the most favorable driving lane based on the calculated route. Here, all curbs (“oncecells”) of the respective driving lanes are given attributes that carry certain information, explained in more detail below.
In this connection, curbs in each driving direction have only one lane situation, otherwise they are divided (see also the basic lane combination with intersection in FIG. 3A , as well as the curb diagram in FIG. 3B assigned to the driving lane combination in FIG. 3A , each in schematic form).
The procedure used in following the course of the lane will be explained via the schematic curb diagram according to FIG. 4B using the example of the complex driving lane situation with two intersections shown in FIG. 4A . The route was calculated in the curb sequence 10 -> 11 -> 12 (see FIG. 4B ). The means of transportation here is on curb 10 , and—according to the present invention—it must be determined which lane is the most advantageous for following the route.
Curb 10 as the starting curb has three lanes:
Driving lane 1 points to curbs 15 and 16 ; curbs 15 and 16 , however, are not part of the route, so that following driving lane 1 may be aborted; Driving lane 2 points to driving lane 1 of curb 11 ; curb 11 belongs to the route, so that driving lane 2 must continue to be followed to curb 11 ; Driving lane 3 points to driving lane 2 of curb 11 ; curb 11 belongs to the route, so that driving lane 3 must continue to be followed to curb 11 .
Now two driving lanes—driving lane 2 and driving lane 3 —of curb 10 have to continue to be followed; unambiguity has not yet been achieved, and the algorithm must be continued.
Curb 11 is the route successor, which means it is the successor curb of curb 10 , and has two lanes that must continue to be followed:
Driving lane 1 points to curbs 12 and 14 ; curb 12 belongs to the route, so that driving lane 1 must continue to be followed to curb 12 ; curb 14 , however, is not part of the route, so that following driving lane 1 on curb 14 is not necessary; Driving lane 2 points to curbs 13 and 14 ; curbs 13 and 14 , however, are not part of the route, so that following driving lane 2 may be aborted.
Now only one lane—lane 1 of curb 11 —must continue to be followed, thus having achieved unambiguity, and the algorithm may be aborted, since driving lane 1 on curb 11 is the only “survivor,” and the predecessor-driving lane 2 on curb 10 is the driving lane to be determined.
The procedure of following lanes will be explained based on another example of the driving lane combination shown in FIG. 5A occasioning necessary lane changes due to the intersecting of two expressways, using the schematic curb diagram according to FIG. 5B . The route was calculated in the curb sequence 10 ′-> 12 ′-> 15 ′. Here, the means of transportation is on curb 10 ′, and it is to be determined, according to the present invention, which driving lane is the most advantageous for following the route.
Curb 10 ′ as the originating curb has two driving lanes:
Driving lane 1 points to driving lane 1 of curb 12 ′; curb 12 ′ belongs to the route, so that driving lane 1 must continue to be followed to curb 12 ′; Driving lane 2 points to driving lane 2 of curb 12 ′; curb 12 ′ belongs to the route, so that driving lane 2 must continue to be followed to curb 12 ′.
Now two lanes—lane 1 and lane 2 —must continue to be followed; unambiguity has not yet been achieved, and the algorithm must be continued.
Curb 12 ′ is the route successor, which means it is the successor curb of curb 10 ′, and has four driving lanes that must continue to be followed:
Driving lane 1 points to curb 13 ′; curb 13 ′, however, is not part of the route, so that following driving lane 1 of curb 12 ′ may be aborted. Driving lane 2 points to curb 14 ′; curb 14 ′, however, is not part of the route, so that following driving lane 2 of curb 12 ′ may be aborted.
Now none of the lanes from curb 10 ′ to be followed runs along the calculated route.
Driving lane 3 points to curb 15 ′; curb 15 ′ belongs to the route, so that driving lane 3 to curb 15 ′, which may be reached by a lane change from driving lane 2 at curb 12 ′, has to continue to be followed. Driving lane 4 points to curb 15 ′; curb 15 ′ belongs to the route, so that driving lane 4 to curb 15 ′, which may be reached by a lane change from driving lane 2 at curb 12 ′ via driving lane 3 , has to continue to be followed.
Now two driving lanes—driving lanes 1 and 2 at curb 15 ′—have “survived,” so that the most advantageous driving lane sequence along the route is as follows:
Driving lane 2 in curb 10 ′
->Driving lane 2 in curb 12 ′ ->Change to driving lane 3 or driving lane 4 in curb 12 ′ ->Driving lane 1 or driving lane 2 in curb 15 ′.
As a result, the method as well as the system according to the present invention may be abstracted in an abstract way in the form of an “entity-relationship” model shown in FIG. 6 , where curb 10 carries digitization direction 82 and length 20 . a. 2 (->reference notation 80 ). Driving lane 84 , being assigned destination name 88 , symbol 86 , and driving lane number 50 . c. 1 , leads back to (->reference notation 90 ) curb 10 .
If this model is then implemented, the driving lanes are introduced into the curbs, wherein the driving lanes of the affected curbs are appended as a new annotation as seen in FIG. 7 :
A curb 10 is assigned a lane list 20 whose elements 20 . a. 1 . 1 , 20 . a. 1 . 2 , 20 . a. 2 contain lane information on the totality of the two driving lanes assigned to curb 10 , namely the lane information
on the driving lanes at the beginning of curb 10 (->reference notation 20 . a. 1 . 1 ), on the driving lanes at the end of curb 10 (->reference notation 20 . a. 1 . 2 ), and on the length of the driving lanes or on the fraction of the length of the driving lanes at curb 10 (->reference notation 20 . a . 2 ).
The sequence of elements 20 . a. 1 . 1 , 20 . a. 1 . 2 , 20 . a. 2 of lane list 20 here corresponds to the actual sequence of the two driving lanes, i.e., the right-hand driving lane corresponds to the first driving lane, and the left-hand driving lane corresponds to the second driving lane, counting from the outer side of the road.
As can be further seen in FIG. 7 , each of the two driving lanes—that is the first (=right-hand) driving lane and the left-hand (second) driving lane—is assigned a lane data list 30 and 40 , respectively, whose elements 30 . b . 1 , 30 . b. 2 and 40 . b . 1 , 40 . b. 2 , respectively, contain lane data information on the particular driving lane.
Elements 30 . b . 1 , 30 . b . 2 and 40 . b . 1 , 40 . b . 2 of lane data lists 30 and 40 , respectively, contain lane data information for each of the driving lanes
on the direction of the driving lane (->reference notation 30 . b . 1 and 40 . b . 1 , respectively) and on the number of the at least one follow-on driving lane succeeding the driving lane (reference notation 30 . b . 2 and 40 . b . 2 , respectively). Furthermore, elements 30 . b . 1 , 30 . b . 2 and 40 . b . 1 , 40 . b . 2 of lane data lists 30 and 40 , respectively, contain additional lane data information such as on special uses of the driving lane or other restrictions on the driving lane.
Finally, FIG. 7 also shows that each follow-on driving lane succeeding the driving lane is assigned a follow-on lane list 50 or 60 or 70 whose elements 50 . c . 1 , 50 . c . 2 , 50 . c . 3 , 50 . c . 4 or 60 . c . 1 , 60 . c . 2 , 60 . c . 3 , 60 . c . 4 or 70 . c . 1 , 70 . c . 2 , 70 . c . 3 , 70 . c . 4 include follow-on lane information on the particular follow-on driving lane interlinked with the lane data information of the preceding driving lane.
Elements 50 . c . 1 , 50 . c . 2 , 50 . c . 3 , 50 . c . 4 or 60 . c . 1 , 60 . c . 2 , 60 . c. 3 , 60 . c . 4 or 70 . c . 1 , 70 . c. 2 , 70 . c . 3 , 70 . c . 4 of follow-on lane list 50 or 60 or 70 include follow-on lane information for each of the follow-on driving lanes
on the follow-on driving lanes at the beginning of assigned curb 11 or 12 or 13 (->reference notation 50 . c . 1 or 60 . c . 1 or 70 . c . 1 ), on the follow-on driving lanes at the end of assigned curb 11 or 12 or 13 (->reference notation 50 . c . 2 or 60 . c . 2 or 70 . c . 2 ), on the direction and/or position of assigned curb 11 or 12 or 13 (->reference notation 50 . c . 3 or 60 . c . 3 or 70 . c . 3 ) and on the number of the follow-on driving lane (->reference notation 50 . c . 4 or 60 . c . 4 or 70 . c . 4 ) according to a reference to the identifier of succeeding assigned curb 11 or 12 or 13 .
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In order to create a method for making available driving lane recommendations for each driving direction relating to at least one curb and interlinked with one another, as well as a system related thereto, which improve the quality of the driving instructions provided by a navigation device via optimized processing of the driving lanes on roads, in particular at intersections, it is recommended that (a) a curb ( 10, 11, 12; 10′, 12′, 15′ ) be assigned at least one lane list ( 20 ) whose elements ( 20 .a .1.1, 20 .a .1.2, 20 .a .2 ) contain lane information on the totality of the driving lanes assigned to the curb ( 10, 11, 12; 10′, 12′, 15 ′); (b) each of the driving lanes be assigned at least one lane data list ( 30; 40 ) whose elements ( 30 .b .1, 30 .b .2; 40 .b .1, 40 .b .2 ) each contain lane data information on the particular driving lane; and (c) each follow-on driving lane succeeding the driving lane be assigned at least one follow-on lane list ( 50; 60; 70 ) whose elements ( 50 .c .1, 50 .c .2, 50 .c .3, 50 .c .4; 60 .c .1, 60 .c .2, 60 . c .3, 60 .c .4; 70 .c .1, 70 .c .2, 70 .c .3, 70 .c .4 ) each contain follow-on lane information, interlinked with the lane data information of the preceding driving lane, on the particular follow-on driving lane.
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FIELD OF THE INVENTION
The invention relates generally to a fiber optic cable guide to permit bendable installation of optical fiber cables and a method of application of the guide to a cable. More particularly, the invention is directed to a fiber optic cable guide that is removably attachable to a connector subassembly disposed at an end of the fiber optic cable and to a related method.
BACKGROUND OF THE INVENTION
Often a fiber optic cable is terminated in a constrained enclosure such as a small cabinet or elsewhere where space is otherwise limited. Sometimes a fiber optic cable is required to bend through about ninety degrees shortly after the termination point. If appropriate care is not given the cable, the bending of the cable may violate the minimum bend radius of the optical fiber, which could lead to attenuation and even breakage of the optical fiber in the cable. Various types of guides have been developed for bendably connecting fiber optic cables to other components without violating the minimum bend radius of the fiber optic cable. For example, guides are available such as those shown in U.S. Pat. Nos. 6,134,370; 5,710,851; 5,640,476; 5,347,603; and 5,037,175.
However, these guide devices include various disadvantages, such as bulkiness that may preclude their use in some applications, especially where small connectors or tight spaces are involved. Also, some of these devices cover most or all of the cable within the bend, making it difficult or impossible to visually detect which cable (for example, according to its color or markings) extends into a given connector. This difficulty can be increased where a large number of cables are connected in a group or where the connected cables extend out of sight beyond the guide. Some of the above guides also must be installed prior to the connector being installed on the optical fiber. Also, some of these devices include the guide as a permanent part of the connector itself, such as incorporating the guide into the boot, thereby precluding the ability to selectively provide a non-guided (i.e., non-bending) connector in the field. Some of these devices are also not readily rotatable relative to the connector after attachment to the connector, thereby limiting installation flexibility. Finally, the devices do not provide for a simple and reliable removal of a cable from the guide, either by choice or in case of an inadvertent snagging of a cable.
SUMMARY OF THE INVENTION
A fiber optic cable guide is disclosed for removable placement on a connectorized fiber optic cable assembly having a fiber optic cable and at least one connector subassembly. The fiber optic cable has a minimum bend radius. The fiber optic cable guide includes an elongated member at least partially curved along its length with a radius of curvature not less than the minimum bend radius of the fiber optic cable for guiding the fiber optic cable in a desired direction. The elongated member has a first end, a second end, a middle section between the first and second ends, and a channel extending from the first end to the second end for receiving the fiber optic cable. The first end is configured to be removably disposed around a portion of the connector subassembly. The second end includes at least one primary securement element extending from the second end and configured to releasably hold at least the fiber optic cable to the elongated member. The middle section includes at least one secondary securement element extending from the middle section and configured to releasably hold at least the fiber optic cable to the elongated member. The primary securement element is configured so that the fiber optic cable is releasable from the primary-securement element upon pulling the fiber optic cable at a first predetermined force in a direction generally away from a bottom of the channel.
The secondary securement element may be configured so that the fiber optic cable is releasable from the secondary securement element upon pulling of the fiber optic cable at a second predetermined force in the direction generally away from the bottom of the channel. The second predetermined force may be greater than the first predetermined force, or the second predetermined force may be substantially equal to the first predetermined force.
The at least one primary securement element may extend arcuately over a portion of the channel, and the second end may include at least two primary securement elements. The at least two primary securement elements may be disposed at two different axial positions along the second end of the elongated member, or the at least two primary securement elements may be disposed opposite each other at a common axial position along the second end of the elongated member, thereby forming a substantially C-shape with the second end.
The connector subassembly may include a strain relief boot, and the at least one primary securement element may be configured to hold the elongated member to the strain relief boot. The first end of the elongated member may be configured to allow the elongated member to rotate 360 degrees relative to the connector subassembly. The first end of the elongated member may have a receptacle extending from the first end, the receptacle defining a longitudinally-extending channel therethrough and a longitudinally-extending slot in communication with the channel. The receptacle may be substantially C-shaped. The slot may be configured to allow the fiber optic cable to be slid radially therethrough. If connector subassembly includes a strain relief boot, the receptacle may be configured to be removably disposed around the boot.
The at least one secondary securement element may be configured to allow axial movement of the fiber optic cable relative to the elongated member, or may be configured to be crimpable around the fiber optic cable to thereby substantially preclude axial movement of the fiber optic cable relative to the elongated member.
The middle section may have at least two secondary securement elements, which may be disposed at two different axial positions along the middle section of the elongated member, or which may be disposed opposite each other at a common axial position along the middle section end of the elongated member, thereby forming a substantially C-shape with the middle section. The at least one secondary securement element may also extend across a center of the channel.
The elongated member may be curved through about 90 degrees, and the channel may have a width that decreases in the direction of the first end to the second end.
Also, the elongated member may include at least one stiffening element. If desired, two ribs extending along the elongated member may be provided for stiffening. The stiffening element may be disposed proximate the secondary securement element or proximate an opening through the elongated member.
According to another aspect of the invention, a fiber optic cable guide is disclosed for removable placement on a connectorized fiber optic cable assembly having a fiber optic cable and at least one connector subassembly. The fiber optic cable has a minimum bend radius. The fiber optic cable guide includes an elongated member at least partially curved along its length with a radius of curvature not less than the minimum bend radius of the fiber optic cable for guiding the fiber optic cable in a desired direction. The elongated member has a first end, a second end, a middle section between the first and second ends, and a channel extending from the first end to the second end for receiving the fiber optic cable. The first end includes a substantially C-shaped receptacle for releasably holding a portion of the connector subassembly. The second end includes two primary securement elements extending from the second end to releasably hold at least the fiber optic cable. The middle section includes one secondary securement element extending from the middle section to releasably hold at least the fiber optic cable. The primary securement elements are configured so that the fiber optic cable is releasable from the primary securement elements upon pulling the fiber optic cable in a direction generally away from a bottom of the channel.
According to another aspect of the invention, a fiber optic cable guide is disclosed for removable placement on a connectorized fiber optic cable assembly having a fiber optic cable and at least one connector subassembly including a strain relief boot. The fiber optic cable has a minimum bend radius. The fiber optic cable guide includes an elongated member curved along its length with a radius of curvature not less than the minimum bend radius of the fiber optic cable. The elongated member has a first end, a second end, a middle section between the first and second ends, and a channel extending from the first end to the second end for receiving the fiber optic cable and the strain relief boot. The first end is removably attached to the strain relief boot. The second end includes at least one primary securement element extending from the second end to releasably hold the fiber optic cable to the elongated member substantially within the channel. The primary securement element is configured so that the fiber optic cable is releasable from the primary securement element upon pulling the fiber optic cable in a direction away from a bottom of the channel.
The elongated member may be forked. Each connector subassembly may include a strain relief boot and each receptacle may be disposed around a respective strain relief boot. The elongated member may include two channels extending from the first end to the second end, each channel for receiving a respective fiber optic cable. The primary securement elements may be configured so that the respective fiber optic cables are releasable upon pulling of the fiber optic cable in a direction away from a bottom of the respective channel. A middle section may be included between the first and second ends and two secondary securement elements disposed on the middle section, each secondary securement element for holding a respective fiber optic cable.
According to another aspect of the invention, a method is disclosed of removably fixing a fiber optic cable in a curvature not greater than that defined by a minimum bend radius of the fiber optic cable, a connector subassembly being disposed at at least one end of the fiber optic cable. The method includes the steps of radially inserting the fiber optic cable into a first end of a guide member, the first end being configured to be disposed around a portion of the connector subassembly, the guide member being at least partially curved along its length with a radius of curvature not less than the minimum bend radius and defining a channel for receiving the fiber optic cable extending from the first end of the guide member to a second end of the guide member, and radially inserting the fiber optic cable in a direction toward the bottom of the channel past at least one securement element extending from the guide member spaced from the first end to hold the fiber optic cable to the guide member.
Further steps may include inserting the fiber optic cable past at least another securement element axially spaced from the at least one securement element, crimping one of the securement elements over the fiber optic cable, axially sliding the guide member along the fiber optic cable after the first radially inserting step, removing the fiber optic cable from the guide member by pulling the cable radially from the at least one securement element, or rotating the guide member relative to the fiber optic cable to a desired orientation after the radially inserting steps.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.
For better understanding of the present invention, reference is made to the following description taken in conjunction with the accompanying drawings and its scope will be pointed out in the appending claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other aspects and advantages of the present invention are apparent from the detailed description below in combination with the drawings, in which:
FIG. 1 is a left side perspective view of one embodiment of a fiber optic cable guide according to the present invention;
FIG. 2 is a sectional view of the fiber optic cable guide taken along line 2 — 2 in FIG. 1;
FIG. 3 is a top perspective view of the fiber optic cable guide of FIG. 1;
FIG. 4 is a partial sectional elevational view of the fiber optic cable guide of FIG. 1, also showing use with a connector subassembly and cable;
FIG. 5 is a side elevational view of the fiber optic cable guide of FIG. 1, also showing use with an alternate connector subassembly and cable;
FIG. 6 is a left side perspective view of an alternative embodiment of a fiber optic cable guide;
FIG. 7 is a perspective view of another alternate embodiment of a fiber optic cable guide having offset securement elements;
FIG. 8 is a top perspective view of an alternative duplex embodiment of a fiber optic cable guide;
FIG. 9 is a top perspective view of another alternate duplex embodiment of a fiber optic cable guide;
FIG. 10 is a left side perspective view of the fiber optic cable guide of FIG. 9 with two connector subassemblies and cables;
FIG. 11 is a top view of fiber optic cable guide of FIG. 9;
FIG. 12 is a left side perspective view of another embodiment of a fiber optic cable guide according to the present invention;
FIG. 13 is a top perspective view of another embodiment of a fiber optic cable guide according to the present invention; and
FIG. 14 is a bottom perspective view of the fiber optic cable guide of FIG. 13 .
DETAILED DESCRIPTION OF THE INVENTION
Detailed reference will now be made to the drawings in which examples embodying the present invention are shown. The drawings and detailed description provide a full and detailed written description of the invention and of the manner and process of using it so as to enable one skilled in the pertinent art to make and use it as well the best mode of carrying out the invention. However, the examples set forth in the drawings and detailed description are provided by way of explanation of the invention and are not meant as a limitation of the invention. The present invention thus includes any modifications and variations of the following examples as come within the scope of the appended claims and their equivalents.
The detailed description uses numerical and lettered designations to refer to figures in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the invention, in particular with reference to corresponding parts in different embodiments.
A first embodiment of a fiber optic cable guide 20 according to the invention is shown in FIGS. 1-5. The fiber optic cable guide 20 is suitable for removable placement on a connectorized fiber optic cable or cable assembly. The fiber optic cable guide 20 includes an elongated member 22 having a first end 24 , a middle section 26 , and a second end 28 . The elongated member 22 defines a channel 23 extending from the first end 24 to the second end 28 . The second end 28 has at least one primary securement element in the form of an extension 30 and the first end 24 has a receptacle 32 .
The receptacle 32 and extension 30 are configured and sized to be removably attached to and safely guide a fiber optic cable 48 through a predetermined bend without violating the minimum bend radius of the fiber optic cable. The cable 48 and a connector subassembly 49 together form what is referred to herein as connectorized fiber optic cable assembly 46 (which may also have a connector at a second end of cable 48 ). As shown, assembly 46 is terminated by an LC connector, but it should be understood that the present invention has applications with various types of connectors. Connector subassembly 49 may include a strain relief boot 50 a or 50 b attached to a housing 51 and a trigger member 53 attached to the housing.
It should also be understood that use of the term “connectorized” is meant to refer both to cables connectorized by a technician in the field and to cables connectorized during initial manufacture. Thus, “connectorized” is intended only to indicate that the fiber optic cable has at least one connector, regardless of how or when installed.
If desired, the extensions 30 may be provided in one or two mating pairs. As shown in FIGS. 1-5 two pairs of the mating extensions 30 are provided. A slot 31 is disposed between each mating extension pair to allow the cable 48 and possibly the strain-relief boot (as described below in relation to the inventive method) to be slid radially through the slot 31 between extensions 30 . It should be understood that the two pairs of mating extensions 30 could be replaced with a single mating pair, if desired. Alternately, each pair could be replaced by a single extension or only a single extension could be employed and still be within the scope of the invention.
As shown, the extensions 30 are arcuate and form a channel 33 in communication with the slot 31 . Channel 33 is coextensive with the channel 23 within the extensions 30 . As shown, a mating pair of extensions 30 are substantially C-shaped, so as to conform to the cable and/or boot exterior. The extensions 30 , whatever their number or form, are configured to be removably disposed around at least a portion of the connectorized cable assembly. FIG. 4 shows the extensions 30 disposed around the cable 48 only, while FIG. 5 shows the extensions 30 disposed around the cable 48 and a boot 50 b (boot 50 a in FIG. 4 does not extend along the cable to the extensions).
The receptacle 32 is configured to be removably disposed around a portion of the connector subassembly 49 . One example of the receptacle, as shown, includes a longitudinally-extending channel 34 (coextensive with channel 23 within the receptacle) and a longitudinally-extending slot 36 that cooperate to permit at least a portion of the cable assembly 46 to be radially inserted into the channel. The receptacle 32 may also be, by way of example, substantially C-shaped. Thus, receptacle 32 is formed of two sides 32 a and 32 b that may be similar to a mating pair of extensions 30 , as described above. Slot 36 should be wide enough for the cable 48 to pass through radially, and may also be wide enough for at least a portion of the boot 50 a or 50 b to pass therethrough.
In use, receptacle 32 and channel 34 releasably secure the elongated member 22 to a portion of the connector subassembly 49 , namely the boot 50 a or 50 b (see FIGS. 4 and 5 ). The receptacle 32 may be configured to grip the boot 50 a or 50 b so as to allow the cable subassembly 46 to rotate 360 degrees relative to the elongated member 22 . If the boot shape is altered, the receptacle 32 may be altered accordingly, whether to allow secure attachment or to ensure rotatability, or both. Such relative rotatability allows for flexibility during installation and maintenance, while still providing minimum bend radius protection. The boot may be configured to accept the guide for example, by providing a groove (not shown) in its outer surface. The receptacle could also be attached to a part of the connector housing 51 , if desired.
The fiber optic cable guide 20 and its channel 23 may be relatively wider near the first end 24 and the receptacle 32 and may decrease in width and diameter towards the second end 28 and extension 30 , as shown. Alternately, the fiber optic cable guide 20 may be axially uniform, having a width equal to that of the channel 34 from the first end and 24 to the second end 28 . The configuration may also be dictated or altered to fit different cable and/or boot configurations and still be within the scope of the invention.
At least one secondary securement element 38 may also be included on guide 20 . If so, the securement element 38 may extend from the middle section 26 and may be configured to extend across a center of the channel 23 . The secondary securement element 38 has a proximal end 40 attached near the middle section 26 of the elongated member 22 and a distal end 42 extending away from the proximal end. The distal end 42 of the secondary securement element 38 may be loosely restrictive relative to the cable 48 and therefore freely allow axial and rotational movement of the cable 48 relative to the elongated member 22 (i.e., both sliding and rotating). Alternatively, the secondary securement element 38 can grip the fiber optic cable 48 tightly (via boot 50 a or 50 b ) so as to eliminate sliding unless the cable is pulled with a fair amount of force, or even can be crimped around the fiber optic cable to preclude sliding in most conditions. To be crimpable, securement element 38 and possibly all of guide 20 , would have to be made of a deformable material, such as a metal.
As shown, the secondary securement element 38 of the first embodiment extends arcuately, and its distal end 42 extends across the center of the channel 23 and therefore further circumferentially around the cable 48 and the boot 50 a or 50 b than do the arms 32 a or 32 b or the extensions 30 . Thus, the cable 48 must be carefully fed around the secondary securement element 38 , if the secondary securement element is so configured, so as to avoid damaging the cable during insertion and especially during removal.
In the exemplary embodiment as shown, the elongated member 22 is curved for at least a portion of its length. More particularly, the member 22 is curved through about ninety degrees but it may also be curved through other angles as desired. Regardless of the circumferential length of the curvature, the curvature (see FIG. 2) should not have a radius of curvature r smaller than the minimum bend radius of the fiber optic cable 48 .
As shown in FIG. 2, the elongated member 22 has a thickness 52 that extends in a plane through which the radius of curvature of the elongated member is curved. The thickness 52 increases in the direction of the first end 24 to provide more strength at that end and more flexibility at the second end 28 . If desired, however, the thickness 52 may be uniform from the first end 24 to the second end 28 , or may vary in other ways, whether uniformly or otherwise, as called for in particular applications.
The elongated member 22 also has a width 54 (FIG. 3) perpendicular to the plane of the radius of curvature. Put another way, a bottom 25 (see FIG. 2) of channel 23 extends along the member 22 in a plane aligned with the radius of curvature r. However, if desired, the curvature could extend in the direction of the width 54 , or in some other direction rather than in the direction of the thickness 52 . Thus, the plane which the radius of curvature extends could be at an angle to or even perpendicular to the plane in which the section was taken in FIG. 2, as will be discussed below with reference to FIG. 10 .
Of course, the guide 20 could be attached on or rotated to anywhere around connector subassembly 46 . For example, the guide 20 (as shown) could be mounted on the connector subassembly 46 with the guide 20 curving down, up, or sideways, regardless of the direction of curvature. Thus, it should be understood that various orientations of the elements described above relative to the curvature of the guide 20 are possible within the scope of the invention.
As shown in FIGS. 4 and 5, the extensions 30 may radially engage the cable 48 or an extended strain relief boot 50 a or 50 b disposed about the cable. The fiber optic cable 48 and the boot 50 may be releasably held by the extension 30 until a user pulls end 48 a of the fiber optic cable 48 away from the extension in a direction generally away from the bottom 25 of the channel 23 (to the right in FIGS. 4 and 5 ). Pulling on the cable 48 causes the cable 48 /boot 50 to be pulled through the extension 30 , thereby releasing the fiber optic cable/boot if pulling is done with force of at least a first predetermined force. The distance between extensions 30 may be configured to release the fiber optic cable/boot upon such pulling with less or more pulling force without causing stress on the fiber cable that could cause attenuation and eventually breakage of the optical fiber in the cable. Securement element 38 provides protection for the fiber optic connector by reducing the force on the connector when the cable is pulled upward relative to the guide 20 with a force that is greater than the first predetermined force. However, due to the extent of extension of the securement element 38 , if the cable 48 is to be removed from the guide one should take care to feed the fiber optic cable around and out of the securement element of this embodiment during continued pulling.
The primary securement element may be sized so as to allow the cable 48 to be released from the guide upon inadvertent snagging of the cable. If so, the possibility is greatly increased for avoiding damage to the cable 48 . Of course, if the cable is more violently pulled, damage to the optical fiber may be unavoidable. With the slots 31 disposed radially above the bottom 25 of channel, rather than to the side, it is also simple to tug the cable 48 upward (away from the bottom 48 of the channel 23 ) to remove it from the second end 28 when one wants to remove the guide 20 from the connectorized cable assembly 46 , or the assembly itself from a receptacle (not shown). The slots and extensions may be thus designed so as to allow the cable 48 to slide out of the slots radially at a first predetermined force, at which a damaging bend of the cable around second end 28 would not occur.
According to another embodiment of the invention as shown in FIG. 6, the middle section 226 of guide 220 may have at least two secondary securement elements 238 a and 238 b that further radially secure a connectorized assembly (not shown) to the elongated member 222 . The securement elements 238 a and 238 b would both extend a lesser distance over the cable than does the securement element 38 , and they more readily allow removal of the cable if pulled upward from the guide 220 . Thus, elements 238 a and 238 b do not extend over the center of channel 223 and are more akin to a mating pair of extensions 30 . Thus, the cable can be pulled upward out of elements 238 a and 238 b , unlike element 38 of the first embodiment.
If desired, the secondary securement elements 238 a , 238 b may be sized so as to allow the cable 48 and boot 50 a / 50 b to slide radially outward in a direction away from the bottom 225 of the channel 223 when the cable is pulled at a second predetermined force. The second predetermined force may be greater than or the same as the first predetermined force. If elements 238 a , 238 b are utilized, sequential or higher levels of protection of the cable if pulled or snagged may be provided depending on the magnitude, speed, and number of pulls the cable experiences.
According to another embodiment of the invention as shown in FIG. 7, securement elements 338 a and 338 b are disposed on a central location of elongated member 322 of guide 330 . Securement elements 338 a and 338 b are offset relative to each other and overlap relative to the center of channel 323 . Thus, elements 338 a and 338 b can be dimensioned the same or similar to element 38 . This embodiment requires that the cable be either slid or manipulated sequentially in two opposing directions around the elements 338 a and 338 b to remove or insert a cable subassembly from or into the guide 320 .
A further embodiment of the invention is shown in FIG. 8 in which a multiplex fiber optic cable guide 420 is configured for removable placement on at least two fiber optic cables 448 . Guide 420 as shown includes a forked elongated member 422 having dual guide bodies 422 a and 422 b with dual channels 423 a and 423 b . As shown in FIG. 8, receptacles 432 a and 432 b may be used to guide the fiber optic cables in a desired direction. At least two securement elements 438 a and 438 b may be used to secure the fiber optic cables. Elements 438 a and 438 b overlap the center of channel 423 , as with element 38 , although they may be configured as are elements 238 or 338 , if desired. Extensions 430 are also provided to receive fiber optic cables (not shown).
At the first end 424 of member 422 , the receptacles 432 a and 432 b are joined. At the middle section 426 and second end 426 , dual guide bodies 422 a and 422 b extend outwardly separately from the first end 424 . However, the guide bodies 422 a and 422 b could be joined along some or all of their lengths, if desired.
FIGS. 9-11 show an alternative embodiment of a multiplex fiber optic cable guide 520 having a forked elongated member 522 having dual guide bodies 522 a and 522 b . Guide 520 differs from guide 420 in that guide 520 includes at least two securement elements 538 a and 538 b on each of guide body 522 a and 522 b . Elements 538 a and 538 b do not extend over channels 523 a and 523 b , as with elements 238 a and 238 b . FIG. 10 shows two cable assemblies 546 secured to guide 520 .
FIG. 12 shows an alternative embodiment a fiber optic cable guide 620 including an elongated member 622 that is similar to that in FIGS. 1-5, except that the curvature of guide 620 extends essentially laterally with reference to the bottom 625 of the channel 623 . Guide 620 demonstrates that the curvature of the guide could extend in various directions with reference to the channel.
FIGS. 13 and 14 show another alternative embodiment of a fiber optic cable guide according to the present invention. As shown, fiber optic cable guide 720 includes an elongated member 722 that is similar to that shown in FIGS. 1-5, except that an opening 756 is located proximate securement element 738 . Opening 756 is also located proximate at least one stiffening element. As shown, the stiffening element may comprise a rib 758 extending along elongated member 722 . Fiber optic cable guide 720 as shown includes two such ribs 758 flanking opening 756 . Ribs 758 are also located proximate securement element 738 , as shown.
An opening (such as opening 756 ) may have to be formed in the elongated member 722 , if the part is made by molding. The presence, size, and location of such an opening is thus dependent on the molding procedure. Thus, opening 765 is not necessarily a required part of the fiber optic cable guide structure according to the present invention, although various openings, shapes, and locations could be included within an elongated member to alter the amount of material, shape, flexibility, etc. of the member within the scope of the present invention. The use of the at least one stiffening element (in this case two ribs 758 ) in the embodiment of FIGS. 13 and 14 compensates for the loss of stiffness in elongated member 722 caused by the presence of opening 756 . The stiffening element also provides a slightly larger surface that can make grasping the elongated member easier in some situations.
It should be understood that the shape and number of stiffening elements could be altered within the scope of the invention. Also, a stiffening element may not be needed, even if a hole is present in the elongated member. Furthermore, at least one stiffening element may be provided on the elongated member regardless of whether any opening extends through the elongated member, and at any desired location along the elongated member whether disposed near an opening, a securement element, or elsewhere. Further, at least one stiffening element may be provided on any of the previously discussed embodiments to stiffen the elongated member.
By way of example with reference to guide 20 , a method of using the disclosed guides is to radially insert the fiber optic cable 48 through into the first end 24 of the guide member 20 . Thus, cable 48 could be slid through slot 36 . Then, the guide member 20 could be slid axially along the cable 48 until the guide member releasably engages the connector subassembly 49 . At this point, the cable can be radially inserted or threaded into the primary and/or secondary securement elements, and then the guide can be rotated into position, if desired. Alternately, any rotation may take place before additional inserting or threading. Also, the axial sliding step can take place after all of the inserting and sliding steps, or the radial insertion could occur with the first end 24 engaging the connector subassembly 49 immediately (i.e., snapping on without requiring axial sliding afterwards).
To remove the cable, the cable may be pulled upwardly in a direction generally away from the bottom 25 of the channel 23 until the cable clears at least the primary securement element(s). Then, the cable may be sequentially pulled from or threaded around the secondary securement elements, if present. Then, the guide may be radially slid off the connector subassembly (boot), or may be axially slid down the cable prior to radial sliding.
Preferably, the guide is made of plastic, but any material could be used that has sufficient strength to cause the boot and cable to curve along the guide. Various other materials, including metals could thus be employed, as could readily be selected by one skilled in the art provided with the present disclosure.
It will be apparent to those skilled in the art that various modification and variations can be made in the present invention without departing from the scope and spirit of the invention. For example, specific shapes of various elements of the illustrated embodiments may be altered to suit particular connector or receptacle applications. Thus, the guides disclosed could be used with or ribbon type cable, and could be reconfigured to be flatter, or smaller or larger, if necessary to do so. Also, the various different configurations and numbers of securement elements could be switched among the embodiments, or the configurations of the receptacle, securement elements, and extensions could also be switched or modified, if desired, to suit the various cable assemblies currently available or that will be available in the future. It is intended that the present invention include such modifications and variations as come within the scope of the appended claims and their equivalents.
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A fiber optic cable guide is disclosed for holding fiber optic cable in a bend without violating the minimum bend radius. The guide is a removably attachable to the fiber optic cable. Duplex embodiments and related methods of use are also disclosed.
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BACKGROUND OF THE INVENTION
This invention relates generally to internal combustion engines and, more particularly, to an improved combustion environment within the cylinders in rotary engines employing reciprocating pistons.
In the familiar internal combustion engine, as well as in the familiar rotary piston type internal combustion engine, the spark plug is typically located in the stationary head of the engine. This configuration provides for the ignition of an air-fuel mixture within the cylinder at the point of the spark plug. The ignition of these gasses can be best described as a rapid burn originating at the point of the spark plug and growing out from that point towards the outward moving piston face. During high-speed operation the speed of the piston can exceed the speed of the burn. When this happens the burn is not yet completed when the exhaust valve opens and the unburned fuel is then expelled into the atmosphere wasting fuel and energy as well as producing higher than normal levels of pollution. On the other hand it is known that high-speed movement of the piston can help control the production of nitrogen oxides (other pollutants). Therefore, a need has developed to have a combination of high-speed piston movement with a more complete combustion.
This invention seeks to address the problem of unburned gasses being expelled into the atmosphere because of uncompleted combustion cycles during the high-speed operation of an internal combustion engine. It further seeks to provide conditions where high-speed piston movement is encouraged during combustion to help control the formation of nitrogen oxides and thereby further reduce toxic emissions. It is yet another goal of this invention to provide a means by which more usable energy can be provided because of a more complete combustion burn cycle, thereby increasing fuel efficiency and reducing fuel usage.
SUMMARY OF THE INVENTION
In contrast to conventional internal combustion engine configurations where the spark plug is located in the stationary engine head, the present invention provides a combined piston and spark plug configuration, hereinafter referred to as plug-in-piston assembly, where the spark plug is attached to and moves in unison with the piston. By initiating the combustion burn from the piston face, as is the purpose of the plug-in-piston design, the burn will now emanate from the movable piston face at a time when the piston is relatively stationary and be directed towards the stationary head of the engine allowing the flame to more completely consume all of the fuel in the cylinder prior to the opening of the exhaust valve. This single action will allow much higher acceleration rates for the piston while providing more complete combustion of the air-fuel mixture increasing output power while reducing fuel consumption and exhaust emissions.
It is therefore the intention of at least one aspect of the invention to provide a plug-in-piston assembly having a novel combination of a piston and spark plug.
In one aspect, the plug-in-piston assembly may include a spark plug threadably attached to and capable of moving in unison with the piston.
In another aspect, the plug-in-piston assembly may include a piston connected to a cylinder sleeve by a wrist pin whereby the wrist pin passes through a cylinder wall. The wrist pin has a tubular configuration and an angular hole provided at its center. There may also be an insulated spark plug body threadably attached to the piston and a spark plug electrode running through it. This electrode extends from the insulated spark plug body to the outside of the wrist pin and is aligned with a wrist pin electrode. The wrist pin electrode may be received through the angular hole on the wrist pin and may extend to lateral ends of the wrist pin. A stationary spark plug located on the stationary outer case transmits electrical energy, which may be received by the wrist pin electrode.
Still another aspect of the present invention may provide a plug-in-piston assembly including a piston having a bore. The bore is used to receive an insulating tube and a head of the spark plug is disposed in said insulating tube.
Another intention of at least one aspect of the invention is to provide an internal combustion engine having a central rotor supporting a plurality of radially extending cylinders rotatable with said rotor about a stationary main shaft. There is also a piston located within the interior surface of each of said cylinders and a spark plug that is attached to and moves in unison with each piston. The piston reciprocates in bearing relation with the interior surface of the cylinder and has a spark plug electrode running through it which extends from the spark plug to the wrist pin. The spark plug electrode is in alignment with the wrist pin electrode. A stationary case having an upper and lower half surrounds the engine coaxially of the stationary main shaft and a pair of cam tracks formed integrally with opposing interior walls is located therein. There is also a pair of cam follower bearings associated with each piston and each bearing operationally engages an adjacent one of the cam tracks whereby combustion actuation of each piston serves to drive the cam followers along said cam tracks.
Another intention of certain aspects of the present invention may be to provide a plug-in-piston assembly for the purpose of initiating a rapid air-fuel burn in a cylinder originating from the face of a movable piston and expanding outward towards the stationary head of the engine.
Yet another intention of certain aspects of the present invention may be to provide a plug-in-piston assembly that allows for a higher and more complete consumption of fuel when compared to a conventional internal combustion engine where the spark plug is located in the stationary engine head.
A further intention of at least one aspect of the present invention may be to provide a plug-in-piston assembly that provides increased power output with reduced fuel consumption when compared to a conventional internal combustion engine where the spark plug is located in the stationary engine head.
Still another intention of certain aspects of the present invention may be to provide a plug-in-piston assembly that produces fewer pollutants as a result of improved combustion when compared to a conventional internal combustion engine where the spark plug is located in the stationary engine head.
Another intention of at least one aspect of the present invention may be to provide a plug-in-piston assembly that can energize the spark plug while it is in motion with the piston.
A further intention of certain aspects of the present invention may be to provide a plug-in-piston assembly that energizes the spark plug while it is in motion with the cylinder.
Finally, another intention of certain aspects of the present invention may be to provide a method of initiating combustion in an internal combustion engine including the steps of providing a spark plug attached to a piston, providing a wrist pin electrode connected to the piston electronically connecting the wrist pin electrode to a spark plug electrode. A further step includes electrically connecting a spark plug electrode to a spark plug and transmitting electrical energy to the wrist pin electrode to produce a spark at the spark plug within the confines of a cylinder thereby initiating combustion. This method may also include the step of providing a second stationary spark plug which transmits electrical energy to the wrist pin electrode.
Having described certain aspects of the present invention, the above and further objects, features and advantages thereof will become readily apparent to those skilled in the art from the following detailed description and illustrations in the accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 is a top elevational view of an assembled rotary engine/generator combination with the top case removed showing the cylinders and pistons of the engine in cross-sectional views.
FIG. 2 is an enlarged sectional top view of the plug-in-piston assembly with sleeve as seen in FIG. 1 .
FIG. 3 is a full cross-section view taken substantially along section line A-A of FIG. 1 to illustrate the side elevation of the assembled arrangement of the parts therein.
FIG. 4 is an enlarged side section view as seen in FIG. 3 to illustrate the assembled arrangement of the plug-in-piston assembly.
FIG. 5 is a further enlarged side section view of the Plug-In-Piston assembly as seen in FIG. 4 showing only the plug-in-piston components.
FIG. 6 is an enlarged side section view of in FIG. 5 .
FIG. 7 is an illustration of the component parts of the plug-in-piston and wrist pin with electrode shown in multiple views.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of a combined piston and spark plug configuration where the spark plug is threadably attached to and moves in unison with the piston will now be described. Although the preferred embodiment provides for the spark plug being threadably attached to the piston, various other conventional means for attaching the spark plug to the piston are acceptable.
In a preferred embodiment disclosed herein, the unitary piston body has an integral connecting rod and an enlarged end at the back or the end opposite of the piston face that is receptive of a transverse wrist pin. A hole is bored and threaded in the face of the piston and on the centerline of the piston to receive the spark plug. An additional hole is bored on the centerline of and through the integral piston connecting rod from the back of the spark plug seat to the transverse bore in the back of the piston provided to receive the transverse wrist pin. This hole through the core of the piston is provided to receive the spark plug electrode and a suitable insulating material. The wrist pin is of a tubular configuration with an angular hole provided at the longitudinal center of the wrist pin and in alignment with the centerline of the wrist pin. This hole is provided to receive the pre-formed end of the wrist pin electrode, which will be in concentric alignment with the spark plug electrode after assembly. The wrist pin electrode is pre-formed with one bent end to align with the spark plug electrode and one expanded end located at one of the longitudinal ends of the wrist pin. In a particular aspect of the present invention where multiple sparks are desired in close proximity, the wrist pin electrode can be made to extend to both ends of the wrist pin. The wrist pin electrode is located along the longitudinal centerline of the wrist pin and secured by a suitable insulating material.
The expanded end of the wrist pin electrode is provided to receive a first spark, which is transmitted from a stationary modified spark plug of a more standard configuration located in the stationary outer case. The electrical energy transmitted from the first spark is carried through the wrist pin electrode to the spark plug electrode producing the desired spark at the point of the spark plug located at the piston face within the confines of the cylinder. The piston is located within the cylinder to reciprocate coaxially thereof in bearing relation with the cylinder's interior surface. The wrist pin extends through slotted openings in the cylinder walls and is coupled to a cam driven yoke or sleeve located exteriorly of the cylinder. The yoke has a cylindrical body, which embraces and rides in bearing relation with the smooth ground exterior of the cylinder during reciprocating activity of the piston.
Turning now to the drawing figures, FIG. 1 is a top view of a rotary engine/generator design having the general features and characteristics of U.S. Pat. No. 6,230,670, the contents of which are hereby incorporated by reference in their entirety. In FIG. 1 , the top view of the engine/generator is shown with the upper case half 1 removed. Also shown is the stationary lower case half 2 and the stationary electrical generating coil 3 that is attached to the case halves. Further depicted is the stationary main shaft 4 around which the rotor 6 rotates with the cylinders 7 and the pistons 8 causing the permanent magnets 9 to move rotationally in close proximity to the stationary coil 3 thereby producing electrical energy. Although the upper case 1 is not shown in FIG. 1 , the positions of one of the two stationary first spark plugs 5 , the outer cam track 10 and the inner cam track I 1 are visible. The cam tracks 10 and 11 are used to move and harness the power of the pistons 8 during operation through their interaction with the cam follower bearings 12 mounted to the cylinder sleeves 13 .
FIG. 2 is an enlarged sectional top view of the plug-in-piston assembly with the cylinder sleeve 13 as seen in FIG. 1 . In FIG. 2 the cylinder sleeve 13 and the cam follower bearing 12 that travel along the outer diameter of the cylinders 7 (not shown in this view) can be seen as well as the wrist pin 14 which is used to connect the piston 8 to the cylinder sleeve 13 . Threadably attached to the face of the piston 8 is the insulated spark plug body 15 . Running through the piston 8 body is the spark plug electrode 16 , which extends from the furthest point of the insulated spark plug body 15 to the outside diameter of the wrist pin 14 where it comes into an insulated alignment with the wrist pin electrode 17 . This arrangement is described in greater detail below.
FIG. 3 is a full side cross-section view taken substantially along section line A-A of FIG. 1 to illustrate the side elevation of the assembled arrangement of the parts therein. In this view the stationary top case half 1 can be seen as well as the stationary lower case half 2 , the stationary coil 3 , the stationary main shaft 4 and the two stationary first spark plugs 5 . The rotor 6 that rotates around the main shaft 4 with the cylinders 7 and the cylinder sleeves 13 can also be seen with the pistons 8 in the cylinders 7 . The cam follower bearings 12 that are mounted to the cylinder sleeves 13 are also shown in this view.
FIG. 4 is an enlarged side section view, as seen in FIG. 3 , to illustrate the assembled arrangement of the plug-in-piston assembly. In FIG. 4 the relationship is shown between the wrist pin 14 as it passes through the slotted walls of the cylinder 7 and is held in place by the set screw 20 . Also depicted is the outer earn track 10 and the inner cam track 11 used to control and harnesses the motion of the piston assembly. In this view, the point of ignition 21 is clearly visible as is the farthest point of the stationary head 37 . When the ignition starts at the piston face and the piston begins to rapidly move away from the head, the flame or burn will continue to move towards the stationary head and point 37 completing the burn before the exhaust valve 38 opens.
FIG. 5 is a further enlarged side section view of the plug-in-piston assembly as seen in FIG. 4 showing only the plug-in-piston components. It includes the first spark plug 5 , which provides the means to jump a spark to the wrist pin electrode 17 , which passes the current to the end of the spark plug electrode 16 causing a final spark to be produced at the tip 21 of the spark plug body 15 within the cylinder 7 , thereby initiating combustion. The wrist pin electrode 17 is fully insulated from the wrist pin 14 by the insulating material 18 . The piston 8 is fully insulated from the spark plug electrode 16 by the insulating tube 19 and the spark plug body 15 is fully insulated from the spark plug electrode 16 by a suitable insulating material 29 . The set screw 20 rests in a slot in the wrist pin 14 insuring proper alignment and positioning of the electrodes 17 and 16 .
FIG. 6 is an enlarged side section view of FIG. 5 . In this view, the relationship between the stationary first spark plug 5 and the moving wrist pin 14 when it is in alignment at the time of ignition is shown. Also depicted is the electrode 22 , which is part of the first spark plug 5 . It is from this electrode 22 in the first spark plug 5 that the first spark is jumped across the gap 23 energizing the wrist pin electrode 17 ultimately causing ignition of the air-fuel mixture within the related cylinder 7 . The wrist pin insulating material 18 is also visible in this view.
FIG. 7 is a component parts break down of the plug-in-piston and wrist pin 14 with the wrist pin electrode 17 shown in multiple views. Viewing in a clockwise rotation starting with the wrist pin 14 which is shown in two views, it is clear that the wrist pin 14 is of a tubular configuration having an angular relief 30 formed on one end of the inside bore, a locating notch 31 used to locate and secure the wrist pin 14 in the transverse bore 35 of the piston 8 and an angular slot 32 provided to receive the angular bent end 34 of the wrist pin electrode 17 . The wrist pin electrode 17 can be seen with the expanded head 33 and the bent end 34 .
The insulating tube 19 is also shown in two views. It is of such size that the outside diameter will be accepted by the bore 25 of the piston 8 and the inside bore of the insulating tube 19 will be receptive of the spark plug electrode 16 fitting firmly between the spark plug head 15 and the wrist pin 14 in assembly. The spark plug head 15 can be seen with insulating material 29 holding the spark plug electrode 16 in a non-conductive position away from the spark plug head 15 . The insulating material 29 provides a closer uniform proximity for the spark to jump, referred to as a spark gap 24 , from the spark plug electrode 16 to the spark plug head 15 during ignition. Four vents 36 are cut into and across the spark plug head 15 to provide for better combustion and vitalization.
Finally, the piston 8 is shown with a bore 25 being receptive of the insulating tube 19 and a threaded bore 27 being receptive of the spark plug assembly. The assembly comprises the spark plug electrode 16 and the spark plug head 15 which is inserted into the insulating tube 19 and threadably attached to the piston face at the threaded bore 27 . Also shown is a threaded hole 26 being receptive of a set screw 20 (see FIG. 5 ) to locate and secure the wrist pin 14 in assembly and a cross-sectional view 28 , showing the cylindrical nature of the piston 8 body.
From the foregoing, it is believed that one of skill in the art will readily recognize and appreciate the novel advancement of this invention over the prior art and will understand that while the same has been described herein and associated with preferred illustrated embodiments thereof, the same is nevertheless susceptible to variation, modification and substitution of equivalents without departing from the spirit and scope of the invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims.
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The combination of a piston with an integrated spark plug to be used in an internal combustion engine is disclosed. The plug-in-piston configuration allows for maximum combustion and fuel efficiency as well as increased power output. Further, the configuration minimizes the release of unburned fuel and pollutants into the atmosphere. A method is also disclosed by which electrical energy is communicated to a spark plug.
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[0001] This application claims the benefit of U.S. Provisional Application No. 61/639,602, filed Apr. 27, 2012, the entire contents of which are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to pantothenate derivatives for the treatment of neurologic disorders (such as pantothenate kinase-associated neurodegeneration), pharmaceutical compositions containing such compounds, and their use in treatment of neurologic disorders.
BACKGROUND
[0003] Pantothenate kinase-associated neurodegeneration (PKAN) is a form, thought to be responsible for half, of neurodegeneration with brain iron accumulation (NBIA) that causes extrapyramidal dysfunction (e.g., dystonia, rigidity, choreoathetosis) (A. M. Gregory and S. J. Hayflick, “Neurodegeneration With Brain Iron Accumulation”, Orphanet Encyclopedia , September 2004). PKAN is thought to be a genetic disorder resulting from lack of the enzyme pantothenate kinase, which is responsible for the conversion of pantothenate (vitamin B-5) to 4′-phosphopantothenate. 4′-Phosphopantothenate is subsequently converted into Coenzyme A (CoA) (as shown below) (R. Leonardi, Y.-M. Zhang, C. O. Rock, and S. Jackowski, “Coenzyme A: Back In Action”, Progress in Lipid Research, 2005, 44, 125-153).
[0000]
[0004] In particular, pantothenate is converted to 4′-phosphopantothenate via the enzyme pantothenate kinase (PANK), which is converted to 4′-phosphopantothenoylcysteine via the enzyme 4′-phosphopantothenoylcysteine synthase (PPCS), and subsequently decarboxylated to 4′-phosphopantethine via 4′-phosphopantothenoylcysteine decarboxylase (PPCDC). 4′-phosphopantethine is then appended to adenosine by the action of phosphosphpantethine adenyltransferease (PPAT) to afford dephospho CoA, which is finally converted to coenzyme A (CoA) via dephospho-CoA kinase (DPCK).
[0005] Classic PKAN usually presents in a child's first ten to fifteen years, though there is also an atypical form that can occur up to age 40. PKAN is a progressively degenerative disease, that leads to loss of musculoskeletal function with a devastating effect on quality of life.
[0006] One approach to treating PKAN could be to use the product of the enzymic reaction, namely, 4′-phosphopantothenate. This approach has been mentioned in the literature, but it has been recognized that the highly charged molecule would not be able to permeate the lipohilic cell membrane (C. J. Balibar, M. F. Hollis-Symynkywicz, and J. Tao, “Pantethine Rescues Phosphopantothenoylcysteine Synthetase And Phosphopantothenoylcysteine Decarboxylase Deficiency In Escherichia Coli But Not In Pseudomonas Aeruginosa”, J. Bacteriol., 2011, 193, 3304-3312).
SUMMARY OF THE INVENTION
[0007] The present invention relates to prodrugs of 4′-phosphopantothenate or a surrogate for 4′-phosphopantothenate. These prodrugs have greater cell permeability than 4′-phosphopantothenate. Without wishing to be bound by any particular theory, it is believed that the replacement of 4′-phosphopantothenate, or the use of a surrogate for it, will permit the body to synthesize CoA or an active variant of it. Thus, these prodrugs are useful for treating disorders resulting from a deficiency of 4′-phosphopantothenate and/or CoA.
[0008] One embodiment of the present invention is a prodrug of 4′-phosphopantothenate (3-{[(2R)-2-hydroxy-3,3-dimethyl-4-(phosphonooxy)butanoyl]amino}propanoic acid). The prodrug may have one or more prodrug moieties attached to the 4′-phosphopantothenate. Preferably, these prodrug moieties reduce the charge of the compound thereby enhancing its cell permeability. In one embodiment, one or more prodrug moieties are attached to the carboxyl group and/or the phosphono group of the 4′-phosphopantothenate. In a preferred embodiment, the prodrug has one prodrug moiety bound to the carboxyl group and two prodrug moieties attached to the phosphono group. In one more preferred embodiment, the hydrogen on one hydroxyl group of the phosphono moiety is replaced with a prodrug moiety, and the other hydroxyl group of the phosphono moiety is replaced with an amino group (e.g., an amino acid, attached through its amino group to the phosphorous atom).
[0009] In one embodiment, the present invention relates to a prodrug of 4′-phosphopantothenate or other compound of the present invention that does not form an ion at physiological pH (e.g., at a pH of between about 7.3 and about 7.5, such as at a pH of between about 7.3 and about 7.4, such as at a pH of about 7.4 or at a pH of about 7.365).
[0010] In another embodiment, the present invention relates to a prodrug of 4′-phosphopantothenate or other compound of the present invention having a pKa value of about 7.
[0011] Another embodiment of the present invention is a compound having the formula:
[0000]
[0000] or a pharmaceutically acceptable salt thereof, wherein
[0012] X is hydroxy, halogen, —OR 6 , or —SR 6 (where R 6 is a C 1 -C 6 alkyl, C 2 -C 6 alkenyl, or C 2 -C 6 alkynyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl);
[0013] Q is a carboxylic acid (—COOH), a sulfinic acid (—SOOH), a sulfonic acid (SOOOH), or an ester thereof (i.e., —COOR 1 , —SOOR 1 , —SOOOR 1 );
[0014] R 1 is selected from substituted or unsubstituted C 1 -C 6 alkyl, substituted or unsubstituted C 2 -C 6 alkenyl, substituted or unsubstituted C 2 -C 6 alkynyl, substituted or unsubstituted C 3 -C 8 cycloalkyl, substituted or unsubstituted C 3 -C 8 cycloalkenyl, substituted or unsubstituted C 3 -C 8 cycloalkyl(C 1 -C 6 alkyl), substituted or unsubstituted C 3 -C 8 cycloalkenyl(C 1 -C 6 alkyl), substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted heteroaryl, substituted and unsubstituted heterocyclylalkyl, and substituted and unsubstituted heteroarylalkyl;
[0015] (a) Z is a phosphonate (—CH 2 P(O)OR 2 ), phosphate (—OP(O)OR 3 R 4 ), a thiophosphonate (—CH 2 P(S)OR 2 ), a thiophosphate (—OP(S)OR 3 R 4 ),
[0000]
[0016] R 2 , R 3 , and R 4 are independently selected from substituted or unsubstituted C 1 -C 6 alkyl, substituted or unsubstituted C 2 -C 6 alkenyl, substituted or unsubstituted C 2 -C 6 alkynyl, substituted or unsubstituted C 3 -C 8 cycloalkyl, substituted or unsubstituted C 3 -C 8 cycloalkenyl, substituted or unsubstituted C 3 -C 8 cycloalkyl(C 1 -C 6 alkyl), substituted or unsubstituted C 3 -C 8 cycloalkenyl(C 1 -C 6 alkyl), substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted heteroaryl, substituted and unsubstituted heterocyclylalkyl, and substituted and unsubstituted heteroarylalkyl;
[0017] R 5 is selected from substituted or unsubstituted C 1 -C 6 alkyl (such as unsubstituted C 1 -C 6 alkyl), substituted or unsubstituted C 2 -C 6 alkenyl, substituted or unsubstituted C 2 -C 6 alkynyl, substituted or unsubstituted C 3 -C 8 cycloalkyl, substituted or unsubstituted C 3 -C 8 cycloalkenyl, substituted or unsubstituted C 3 -C 8 cycloalkyl(C 1 -C 6 alkyl), substituted or unsubstituted C 3 -C 5 cycloalkenyl(C 1 -C 6 alkyl), substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted heteroaryl, substituted and unsubstituted heterocyclylalkyl, and substituted and unsubstituted heteroarylalkyl;
[0018] Y is a natural or unnatural amino acid ester of the formula
[0000]
[0019] R 7 is selected from substituted or unsubstituted C 1 -C 6 alkyl (such as unsubstituted C 1 -C 6 alkyl), substituted or unsubstituted C 2 -C 6 alkenyl, substituted or unsubstituted C 2 -C 6 alkynyl, substituted or unsubstituted C 3 -C 8 cycloalkyl, substituted or unsubstituted C 3 -C 8 cycloalkenyl, substituted or unsubstituted C 3 -C 8 cycloalkyl(C 1 -C 6 alkyl), substituted or unsubstituted C 3 -C 8 cycloalkenyl(C 1 -C 6 alkyl), substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted heteroaryl, substituted and unsubstituted heterocyclylalkyl, and substituted and unsubstituted heteroarylalkyl;
[0020] R 8 and R 9 are independently selected from hydrogen, amino acid side chains, C 1 -C 6 alkyl, substituted or unsubstituted C 2 -C 6 alkenyl, substituted or unsubstituted C 2 -C 6 alkynyl, substituted or unsubstituted C 3 -C 8 cycloalkyl, substituted or unsubstituted C 3 -C 8 cycloalkenyl, substituted or unsubstituted C 3 -C 8 cycloalkyl(C 1 -C 6 alkyl), substituted or unsubstituted C 3 -C 8 cycloalkenyl(C 1 -C 6 alkyl), substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted heteroaryl, substituted and unsubstituted heterocyclylalkyl, and substituted and unsubstituted heteroarylalkyl;
[0021] with the proviso that R 8 and R 9 are not both hydrogen.
[0022] In one preferred embodiment, the amino acid side chain in the definition of R 8 and R 9 is that of a natural amino acid (e.g., an L-amino acid). In formula F, R 8 and R 9 may be attached to the carbon depicted such that the carbon has the R or S absolute configuration (D or L relative configuration). In a more preferred embodiment, one of R 8 and R 9 is hydrogen and the other is an amino acid side chain (preferably, an amino acid side chain of a natural L-amino acid, such as a proteinogenic amino acid).
[0023] Another embodiment is a compound having the formula:
[0000]
[0000] or a pharmaceutically acceptable salt thereof, wherein
[0024] R is an amino acid side chain;
[0025] R′ is selected from C 1 -C 6 alkyl substituted or unsubstituted C 1 -C 6 alkyl (such as unsubstituted C 1 -C 6 alkyl), substituted or unsubstituted C 2 -C 6 alkenyl, substituted or unsubstituted C 2 -C 6 alkynyl, substituted or unsubstituted C 3 -C 5 cycloalkyl, substituted or unsubstituted C 3 -C 5 cycloalkenyl, substituted or unsubstituted C 3 -C 5 cycloalkyl(C 1 -C 6 alkyl), substituted or unsubstituted C 3 -C 5 cycloalkenyl(C 1 -C 6 alkyl), substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted heteroaryl, substituted and unsubstituted heterocyclylalkyl, and substituted and unsubstituted heteroarylalkyl; and
[0026] R″ is selected from substituted or unsubstituted C 1 -C 6 alkyl, substituted or unsubstituted C 2 -C 6 alkenyl, substituted or unsubstituted C 2 -C 6 alkynyl, substituted or unsubstituted C 3 -C 5 cycloalkyl, substituted or unsubstituted C 3 -C 8 cycloalkenyl, substituted or unsubstituted C 3 -C 8 cycloalkyl(C 1 -C 6 alkyl), substituted or unsubstituted C 3 -C 8 cycloalkenyl(C 1 -C 6 alkyl), substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted heteroaryl, substituted and unsubstituted heterocyclylalkyl, and substituted and unsubstituted heteroarylalkyl.
[0027] In one preferred embodiment, the amino acid side chain in the definition of R is that of a natural amino acid (e.g., a natural L-amino acid). R may be attached to the carbon depicted such that the carbon has the R or S absolute configuration (D or L relative configuration). In a more preferred embodiment, R is the side chain of a proteinogenic amino acid. In one preferred embodiment, the stereochemistry of the R group is such that the molecule has the following stereochemistry:
[0000]
[0028] In one embodiment of the compound of formula G, R′ is C 1 -C 6 alkyl (e.g., methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl), benzyl, cyclohexyl, and methylcyclopropyl.
[0029] In one embodiment of the compound of formula G, R″ is C 1 -C 6 alkyl (e.g., methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl), benzyl, cyclohexyl, and methylcyclopropyl.
[0030] Another embodiment is a compound having the formula:
[0000]
[0000] or a pharmaceutically acceptable salt thereof, wherein
[0031] R is an amino acid side chain;
[0032] X is halogen (e.g., F);
[0033] n is 0, 1, 2, 3, 4 or 5 (e.g., 0, 1 or 2);
[0034] R′ is selected from C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 3 -C 8 cycloalkyl, C 3 -C 5 cycloalkenyl, C 3 -C 8 cycloalkyl(C 1 -C 6 alkyl), C 3 -C 8 cycloalkenyl(C 1 -C 6 alkyl), aryl, arylalkyl, heterocyclyl, heteroaryl, heterocyclylalkyl, and heteroarylalkyl; each of which is optionally substituted by one or more halogen (e.g., fluorine); and
[0035] R″ is selected from C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 3 -C 8 cycloalkyl, C 3 -C 8 cycloalkenyl, C 3 -C 8 cycloalkyl(C 1 -C 6 alkyl), C 3 -C 8 cycloalkenyl(C 1 -C 6 alkyl), aryl, arylalkyl, heterocyclyl, heteroaryl, heterocyclylalkyl, and heteroarylalkyl; each of which is optionally substituted by one or more halogen (e.g., fluorine).
[0036] In one preferred embodiment, n is 0. In another preferred embodiment n is 1.
[0037] In one preferred embodiment, the amino acid side chain in the definition of R is that of a natural amino acid (e.g., a natural L-amino acid). R may be attached to the carbon depicted such that the carbon has the R or S absolute configuration (D or L relative configuration). In a more preferred embodiment, R is the side chain of a proteinogenic amino acid. In one preferred embodiment, the stereochemistry of the R group is such that the molecule has the following stereochemistry:
[0000]
[0038] In one embodiment of the compound of formula H, R′ is C 1 -C 6 alkyl (e.g., methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, or t-butyl), benzyl, cyclohexyl, or methylcyclopropyl, each of which is optionally substituted by one or more halogen (e.g., fluorine).
[0039] In one embodiment of the compound of formula H, R″ is C 1 -C 6 alkyl (e.g., methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, or t-butyl), benzyl, cyclohexyl, or methylcyclopropyl, each of which is optionally substituted by one or more halogen (e.g., fluorine).
[0040] Preferred compounds of the present invention include those having the formula:
[0000]
[0000] or a pharmaceutically acceptable salt thereof, wherein
[0000] R (AA) R′ R″ L-Ala Et Et L-Ala Me Me L-Ala n Bu n Bu L-Ala Bn Et L-Ala Et Bn L-Ala Bn Bn L-Ala MeCyPr MeCyPr Gly Et Et Gly Bn Bn Gly Bn Et Gly Et Bn L-Val Et Et L-Trp Me Me L-Trp Et Et L-Trp Bn Et L-Trp Et Bn L-Trp Bn Bn
(wherein Bn is benzyl, Cy is cyclohexyl, Et is ethyl, hex is hexyl, iBu is isobutyl, iPr is isopropyl, Me is methyl, MeCyPr is methylcyclopropyl (i.e., —CH 2 -cyclopropyl, and Melndole is (1H-indol-3-yl)methyl). In one embodiment, the compounds mentioned above have the following stereochemistry:
[0000]
[0041] Yet another embodiment is a pharmaceutical composition comprising a compound of the present invention, and a pharmaceutically acceptable excipient. In one embodiment, the pharmaceutical composition includes an effective amount of the compound to treat a neurologic disorder. The pharmaceutical composition may be a dosage unit form, such as a tablet or capsule.
[0042] Yet another embodiment is a method of treating a disorder associated with a deficiency of pantothenate kinase, 4′-phosphopantothenate, or Coenzyme A in a subject. The method comprises administering to the subject an effective amount of a compound of the present invention.
[0043] Yet another embodiment is a method of treating pantothenate kinase-associated neurodegeneration in a subject. The method comprises administering to the subject an effective amount of a compound of the present invention. The subject may suffer from neurodegeneration with brain iron accumulation.
[0044] Yet another embodiment is a method of treating Parkinson's disease in a subject. The method comprises administering to the subject an effective amount of a compound of the present invention.
[0045] Yet another embodiment is a method of treating cells or tissue involved in a pathology characterized by abnormal neuronal function in a subject. The method comprises administering to the subject an effective amount of a compound of the present invention. The pathology may be selected from dystonia, extrapyramidal effects, dysphagia, rigidity and/or stiffness of limbs, choreoathetosis, tremor, dementia, spasticity, muscle weakness, and seizure.
[0046] Yet another embodiment is a method of treating cells or tissues involved in a pathology characterized by dysfunctional neuronal cells caused by misregulation of the gene associated with the enzyme pantothene kinase. The method comprises administering to the subject an effective amount of a compound of the present invention.
[0047] Yet another embodiment is a method of treating a pathology characterized by dysfunctional neuronal cells caused by misregulation of the gene associated with the enzyme pantothene kinase in a subject. The method comprises administering to the subject an effective amount of a compound of the present invention.
[0048] Yet another embodiment is a method of treating cells or tissues involved in a pathology characterized by dysfunctional neuronal cells caused by misregulation of the expression of the gene associated with the enzyme pantothene kinase. The method comprises administering to the subject an effective amount of a compound of the present invention.
[0049] Yet another embodiment is a method of treating a pathology characterized by dysfunctional neuronal cells caused by misregulation of the expression of the gene associated with the enzyme pantothene kinase in a subject. The method comprises administering to the subject an effective amount of a compound of the present invention.
[0050] Yet another embodiment is a method of treating a subject having neuronal cells with an over accumulation of iron. The method comprises administering to the subject an effective amount of a compound of the present invention.
[0051] In the aforementioned methods, the subject may be a child (for example, 10 to 15 years old) or an adult.
[0052] Yet another embodiment is a method of preparing a compound of formula G or H by:
(a) protecting both hydroxyl groups of pantothenic acid; (b) esterifying the acid moiety of the protected pantothenic acid to form a compound of the formula:
[0000]
[0000] where each Pg independently represent a protecting group, and R″ is defined as above with respect to formula G or H;
(c) deprotecting the hydroxyl groups; (d) phosphorylating the deprotected compound with a compound of the formula:
[0000]
[0000] wherein L is a leaving group (e.g., halogen such as chloro), and R and R′ are defined as above with respect to formula G or H; and
(e) optionally, forming a salt of the compound formed in step (d).
[0058] Yet another embodiment is a method of preparing a compound of formula G or H by:
[0059] (a) esterifying pantothenic acid with an alcohol of the formula R″OH to form a compound of the formula:
[0000]
[0000] wherein R″ is defined as above with respect to formula G or H;
[0060] (b) phosphorylating the esterified compound with a compound of the formula:
[0000]
[0000] wherein L is a leaving group (e.g., halogen), and R and R′ are defined as above with respect to formula G or H; and
[0061] (c) optionally, forming a salt of the compound formed in step (b). The esterification in step (a) can be performed by subjecting pantothenic acid to Fischer esterification conditions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0062] FIG. 1 is a bar graph showing the levels of acetyl CoA in human HEK 293T cells, as measured by mass spectrometry, following treatment with the compounds of Examples 2, 5, 7 and 12.
[0063] FIG. 2 is a bar graph showing levels of mBBr CoA in untreated Pank 1+/+ mice (WT), untreated Pank 1−/− knock out mice (pank1KO) and PANK knockout mice following administration of the compound of Example 2 (Pank KO+Example 2).
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0064] As used herein, certain items may have the following define meanings
[0065] As used in the specification and claims, the singular for “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a cell” includes a plurality of cells, including mixtures thereof. Similarly, use of “a compound” for treatment of preparation of medicaments as described herein contemplates using one or more compounds of the invention for such treatment or preparation unless the context clearly dictates otherwise.
[0066] As used herein, the term “comprising” is intended to mean that the compositions and methods include the recited elements, but not excluding others. Thus, a composition consisting essentially of the elements as defined herein would not exclude trace contaminants from the isolation and purification method and pharmaceutically acceptable carriers, such as phosphate buffered saline, preservatives, and the like. “Consisting of” shall mean excluding more than trace elements of other ingredients and substantial method steps for administering the composition of this invention. Embodiments defined by each of the transitional terms are within the scope of this invention.
[0067] The term “alkyl” refers to a straight or branched hydrocarbon chain radical consisting solely of carbon and hydrogen atoms, containing no unsaturation. Unless otherwise specified, the term “alkyl” refers to a group having from one to eight carbon atoms (for example, one to six carbon atoms, or one to four carbon atoms), and which is attached to the rest of the molecule by a single bond. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, s-butyl, n-pentyl, and s-pentyl.
[0068] The term “alkenyl” refers to an aliphatic hydrocarbon group containing a carbon-carbon double bond and which may be a straight or branched or branched chain. Unless otherwise specified, the term “alkenyl” refers to a group having 2 to about 10 carbon atoms, e.g., ethenyl, 1-propenyl, 2-propenyl (allyl), iso-propenyl, 2-methyl-1-propenyl, 1-butenyl, and 2-butenyl.
[0069] The term “alkynyl” refers to a straight or branched chain hydrocarbyl radical having at least one carbon-carbon triple bond. Unless otherwise specified, the term “alkynyl” refers to a group having in the range of 2 up to about 12 carbon atoms (for instance, 2 to 10 2 to 10 carbon atoms), e.g., ethynyl, propynyl, and butnyl.
[0070] The term “cycloalkyl” denotes a non-aromatic mono or multicyclic ring system of about 3 to 12 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.
[0071] The term “cycloalkylalkyl” refers to a cyclic ring-containing radical containing in the range of about 3 up to 8 carbon atoms directly attached to an alkyl group which is then attached to the main structure at any carbon in the alkyl group that results in the creation of a stable structure such as cyclopropylmethyl, cyclobutylethyl, and cyclopentylethyl.
[0072] The term “aryl” refers to a mono- or multi-cyclic aromatic radical having in the range of 6 up to 20 carbon atoms such as phenyl, naphthyl, tetrahydronapthyl, indanyl, and biphenyl.
[0073] The term “arylalkyl” refers to an aryl group as defined above directly bonded to an alkyl group as defined above, e.g., —CH 2 C 6 H 5 , and —C 2 H 5 C 6 H 5 .
[0074] The term “heterocyclyl” refers to a non-aromatic 3 to 15 member ring radical which, consists of carbon atoms and at least one heteroatom selected from nitrogen, phosphorus, oxygen and sulfur. The heterocyclic ring radical may be a mono-, bi-, tri- or tetracyclic ring system, which may include fused, bridged or spiro ring systems, and the nitrogen, phosphorus, carbon, oxygen or sulfur atoms in the heterocyclic ring radical may be optionally oxidized to various oxidation states. In addition, the nitrogen atom may be optionally quaternized.
[0075] The term “heterocyclylalkyl” refers to a heterocyclyl group as defined above directly bonded to an alkyl group as defined above.
[0076] The term “heteroaryl” refers to an optionally substituted 5-14 member aromatic ring having one or more heteroatoms selected from N, O, and S as ring atoms. The heteroaryl may be a mono-, bi- or tricyclic ring system. Examples of such heteroaryl ring radicals includes but are not limited to oxazolyl, thiazolyl imidazolyl, pyrrolyl, furanyl, pyridinyl, pyrimidinyl, pyrazinyl, benzofuranyl, indolyl, benzothiazolyl, benzoxazolyl, carbazolyl, quinolyl and isoquinolyl.
[0077] The term “heteroarylalkyl” refers to an heteroaryl group as defined above directly bonded to an alkyl group as defined above, e.g., —CH 2 C 6 H 4 N, and —C 2 H 5 C 6 H 4 N.
[0078] The term “halogen” includes F, Cl, Br, and I.
[0079] The term “amino acid side chain” refers to the side chain R of an alpha amino acid of the formula H 2 N—CH(R)—COOH. For example, the side chain of alanine is methyl, the side chain of glycine is hydrogen, the side chain of valine is iso-propyl, and the side chain of tryptophan is (1H-indol-3-yl)methyl. Suitable amino acid side chains in the compounds of the present invention include those of natural amino acids, including proteinogenic amino acids. Non-limiting examples of natural amino acids include Standard amino acids or proteinogenic amino acids include but are not limited to alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, pyrrolysine, selenocysteine, serine, threonine, tryptophan, tyrosine and valine.
[0080] The term “substituted”, unless otherwise specified, refers to substitution with any one or any combination of the following substituents: hydrogen, hydroxy, halogen, carboxyl, cyano, nitro, oxo (═O), thio(═S), alkyl, alkoxy, alkenyl, alkynyl, aryl, arylalkyl, cycloalkyl, cycloalkenyl, aryl, heterocyclyl, heteroaryl, —COOR x , —C(O)R x , —C(S)R x , —C(O)NR x R y , —C(O)ONR x R y , —NR y R z , —NR x CONR y R z , —N(R x )SOR y , —N(R x )SO 2 R y , —(═N—N(R x )R y ), —NR x C(O)OR y , —NR x R y , —NR x C(O)R y —, —NR x C(S)R y —NR x C(S)NR y R z , —SONR x R y —, —SO 2 NR x R y —, —OR x , —OR x C(O)NR y R z , —OR x C(O)OR y —, —OC(O)R x , —OC(O)NR x R y , —R x NR y C(O)R z , —R x OR y , —R x C(O)OR y , —R x C(O)NR y R z , —R x C(O)R x , —R x OC(O)R y , —SR x , —SOR x , —SO 2 R x , and —ONO 2 , wherein R x , R y and R z in each of the above groups can be hydrogen atom, alkyl, alkoxy, alkenyl, alkynyl, aryl, arylalkyl, cycloalkyl, cycloalkenyl, amino, aryl, heteroaryl, heterocyclyl, or any two of R x , R y and R z may be joined to form a saturated or unsaturated 3-10 member ring, which may optionally include heteroatoms which may be same or different and are selected from O, NH or S. In one embodiment, the term substituted refers to substitution with one or more halogens (e.g., fluorine).
[0081] The term “subject” refers to a mammal, such as a domestic pet (for example, a dog or cat), or human. Preferably, the subject is a human.
[0082] The phrase “effective amount” refers to the amount which, when administered to a subject or patient for treating a disease, is sufficient to effect such treatment for the disease.
[0083] “Treatment” or “treating” includes (1) inhibiting a disease in a subject or patient experiencing or displaying the pathology or symptomatology of the disease (e.g., arresting further development of the pathology and/or symptomatology), (2) ameliorating a disease in a subject or patient that is experiencing or displaying the pathology or symptomatology of the disease (e.g., reversing the pathology and/or symptomatology), and/or (3) effecting any measurable decrease in a disease in a subject or patient that is experiencing or displaying the pathology or symptomatology of the disease.
Pharmaceutical Formulations and Routes of Administration
[0084] The compounds of the present invention may be administered by a variety of routes including orally and by injection (e.g. subcutaneously, intravenously, and intraperitoneally).
[0085] The compounds may be administered orally in the form of a solid or liquid dosage form. In both, the compound may be coated in a material to protect it from the action of acids and other natural conditions which may inactivate the compound. The compounds may be formulated as aqueous solutions, liquid dispersions, (ingestible) tablets, buccal tablets, troches, capsules, elixirs, suspensions, syrups, and wafers. The oral dosage forms may include excipients known in the art, such as binders, disintegrating agents, flavorants, antioxidants, and preservatives. Liquid dosage forms may include diluents such as saline or an aqueous buffer.
[0086] The compounds may also be administered by injection. Formulations suitable for injection may include sterile aqueous solutions (where water soluble) or dispersions, and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions. The composition may be sterile and be fluid to the extent that easy syringability exists. It may be stable under the conditions of manufacture and storage and be preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (such as, glycerol, propylene glycol, and liquid polyethylene glycol), suitable mixtures thereof, and vegetable oils. The proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of dispersion and by the use of surfactants. Prevention of the action of microorganisms can be achieved by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, and ascorbic acid. In many cases, it will be preferable to include isotonic agents, for example, sugars, sodium chloride, or polyalcohols such as mannitol and sorbitol, in the composition. Prolonged absorption of the injectable compositions can be brought about by including in the composition an agent which delays absorption, for example, aluminum monostearate or gelatin.
[0087] Sterile injectable solutions can be prepared by incorporating the therapeutic compound in the required amount in an appropriate solvent with one or a combination of ingredients enumerated above, as required, followed by filtered sterilization. Generally, dispersions are prepared by incorporating the therapeutic compound into a sterile carrier which contains a basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the preparation of sterile injectable solutions, the methods of preparation include vacuum drying and freeze-drying which yields a powder of the active ingredient (i.e., the therapeutic compound) plus any additional desired ingredient from a previously sterile-filtered solution thereof.
[0088] The actual dosage amount of the compound administered to a subject may be determined by physical and physiological factors such as age, sex, body weight, severity of condition, the type of disease being treated, previous or concurrent therapeutic interventions, idiopathy of the subject and on the route of administration. These factors may be determined by a skilled artisan. The practitioner responsible for administration will typically determine the concentration of active ingredient(s) in a composition and appropriate dose(s) for the individual subject.
[0089] In one embodiment, a human subject is administered the daily doses of from about 0.01 mg/kg to about 100 mg/kg.
[0090] Single or multiple doses of the compounds are contemplated. Desired time intervals for delivery of multiple doses can be determined by one of ordinary skill in the art employing no more than routine experimentation. As an example, subjects may be administered two doses daily at approximately 12 hour intervals. In some embodiments, the compound is administered once a day.
[0091] The compounds may be administered on a routine schedule. As used herein a routine schedule refers to a predetermined designated period of time. The routine schedule may encompass periods of time which are identical or which differ in length, as long as the schedule is predetermined. For instance, the routine schedule may involve administration twice a day, every day, every two days, every three days, every four days, every five days, every six days, a weekly basis, a monthly basis or any set number of days or weeks there-between. Alternatively, the predetermined routine schedule may involve administration on a twice daily basis for the first week, followed by a daily basis for several months. In other embodiments, the invention provides that the agent(s) may taken orally and that the timing of which is or is not dependent upon food intake. Thus, for example, the agent can be taken every morning and/or every evening, regardless of when the subject has eaten or will eat.
Combination Therapy
[0092] In addition to being used as a monotherapy, the compounds may also find use in combination therapies. Effective combination therapy may be achieved with a single composition or pharmacological formulation that includes both agents, or with two distinct compositions or formulations, administered at the same time, wherein one composition includes a compound of this invention, and the other includes the second agent(s). Alternatively, the therapy may precede or follow the other agent treatment by intervals ranging from minutes to months.
[0093] The additional agent or agents may be selected from any agent or agents useful for treating a neurological disorder, for example any agent or agents useful for treating a deficiency of pantothenate kinase, 4′-phosphopantothenate, or Coenzyme A. In one embodiment, the additional agent or agent is useful in improving cognitive function, e.g., an acetylcholinesterase inhibitor, such as physostigmine, neostigmine, pyridostigmine, ambenonium, demarcarium, rivastigmine, galantamine, donezepil, and combinations thereof. In another embodiment, the additional agent or agents is an iron chelator, such as deferiprone, deferoxamine, deferasirox, and combinations thereof.
Synthesis of Phosphopantothenate Derivatives
[0094] The compounds of the present invention can be prepared from pantothenic acid (vitamin B5), which is readily available. The synthesis of pantothenic acid is described, for example, in U.S. Pat. Nos. 2,676,976 and 2,870,188.
[0095] The following synthesis for preparing the compounds of formula G can be adapted to prepare other compounds of the present invention, such as compounds of formula H. The compound of formula G can be prepared by (a) protecting both hydroxyl groups of pantothenic acid, (b) esterifying the acid moiety of the protected pantothenic acid to form a compound of the formula:
[0000]
[0000] where each Pg independently represent a protecting group, and R″ is defined as above with respect to formula G, (c) deprotecting the hydroxyl groups, (d) phosphorylating the deprotected compound with a compound of the formula:
[0000]
[0000] wherein L is a leaving group (e.g., halogen), and R and R′ are defined as above with respect to formula G; and (e) optionally, forming a salt of the compound formed in step (d). This reaction scheme is shown below (where L is Cl):
[0000]
[0000] (Note: R 1 in the last step can be hydrogen.)
[0096] The protection step (a) can be performed by treating pantothenic acid with benzaldehyde and zinc chloride to afford the corresponding acetal (T. W. Green and P. G. M. Wuts, Protective Groups in Organic Synthesis , Wiley-Interscience, New York, 1999, 217-224, 716-719). The pantothenic acid may also be protected by treatment of pantothenic acid with acetone and toluene sulfonic acid (M. Carmack and C. J. Kelley, “Synthesis of optically active Cleland's reagent [(−)-1,4-dithio-L-threitol]”, J. Org. Chem., 1968, 33, 2171-2173) to afford the corresponding acetal. In another example, pantothenic acid is treated with sodium hydride followed by benzyl bromide to afford the di-O-benzylated pantothenic acid (T. W. Green et al., supra).
[0097] After diprotection of the hydroxyl groups, formation of an ester (R″) may be accomplished by, for example, reacting the diprotected pantothenic acid with an appropriate alcohol, and dicyclohexyldicarbodimide (DCC), or diethylazodicarboxylate (DEAD) and triphenylphosphine (a Mitsunobu reaction). Alternatively, the protected pantothenic acid can be converted to the corresponding acid chloride (for example, with thionyl chloride or oxalyl chloride), followed by treatment with the corresponding alcohol.
[0098] Deprotection can be performed by any method known in the art, such as described in T. W. Green et al., supra.
[0099] As an alternative to steps (a) to (c), pantothenic acid can be esterified with an alcohol of the formula R″OH, for example, by subjecting pantothenic acid to Fischer esterification conditions (i.e., excess alcohol, and catalytic acid under reflux).
[0100] The primary hydroxyl group on the compound formed in step (c) can be selectively phosphorylated. See J. D. Patrone, J. Yao, N. E. Scott, and G. D. Dotson, “Selective Inhibitors of Bacterial Phosphopantothenoylcysteine Synthetase”, J. Am. Chem. Soc., 2009, 131, 16340-16341). The conditions described in D. M. Lehsten, D. N. Baehr, T. J. Lobl, and A. R. Vaino, “An Improved Procedure for the Synthesis of Nucleoside Phosphoramidates”, Organic Process Research & Development, 2002, 6, 819-822, can be used for this reaction.
[0101] This method is shown below with a method for preparating the phosphorylation reagent.
[0000]
[0102] Optionally, an optically pure product can be obtained by performing a chiral separation of the final product, or one of the intermediates between steps in the synthesis.
[0103] Alternatively, the compounds of the present invention can be prepared by the route described in B. S. Ross, P. G. Reddy, H.-R. Zhang, S. Rachakonda, and M, J. Sofia, “Synthesis of Diastereomerically Pure Nucleotide Phosphoramidates”, J. Org. Chem., 2011, 76, 8311-8319. This route can produce an optically pure product without performing a final chiral separation step.
EXAMPLES
Example 1
Synthesis of ethyl 3-((2R)-4-(((((S)-1-ethoxy-1-oxopropan-2-yl)amino)(phenoxy)phosphoryl)oxy)-2-hydroxy-3,3-dimethylbutanamido)propanoate
[0104]
[0105] L-Alanine ethyl ester hydrochloride (0.50 g, 3.25 mmol) was suspended in 10 mL of CH 2 Cl 2 and treated with phenyl phosphorodichloridate (0.50 mL, 3.35 mmol) at −10° C. and under an atmosphere of nitrogen. The well-stirred mixture was then treated dropwise with N-methylimidazole (1.0 mL, 12.5 mmol). After 1 hr. and still at −10° C., ethyl pantothenate (0.70 g, 2.8 mmol) in 3 ml, of CH 2 Cl 2 was added slowly. This mixture was allowed to warm to room temperature, and after 3 hrs, 2 mL of methanol was added. Extraction was performed sequentially with 1 M HCl, water, 5% NaHCO 3 , and brine. The organic phase was dried (Na 2 SO 4 ), and the solvent was evaporated affording 1.11 g of a clear, colorless syrup. This material was purified by flash column chromatography using 30 g of silica gel and eluting with 1:1 EtOAc/hexanes containing 5% EtOH. The process was repeated until 1.1 g of phosphoramidate was obtained. HPLC showed the product, as a 1:1 mixture of disastereomers, having a purity of 97%. 1 H NMR (300 MHz, CDCl 3 ): δ 1.08 (s, 3H, CH 3 ), 1.21 (d, 3H, J=2.7 Hz, CH 3 ), 1.27 (m, 6H, CH 3 ), 1.35 (t, 3H, J=6.9 Hz, CH 3 ), 2.53 (q, 2H, J=4.2 Hz, CH 2 ), 3.50 (m, 2H, CH 2 ), 3.60 (m, 1H, CH), 3.78 (d, J=7.5 Hz, CH), 3.9 (m, 2H, CH 2 ), 4.10 (m, 6H, CH 2 ), 4.79 (t, 1H, J=6.5 Hz, CH), 7.15 and 7.40 (2Ms, 5H, Ph). Expected Mol. Wt. 502.21, Observed Mol. Wt. 503.09 (M+H + ]
Example 2
Synthesis of methyl 3-((2R)-2-hydroxy-4-(((((S)-1-methoxy-1-oxopropan-2-yl)amino)(phenoxy) phosphoryl)oxy)-3,3-dimethylbutanamido)propanoate
[0106]
[0107] L-alanine methyl ester hydrochloride (1.35 g, 9.65 mmol) was suspended in dichloromethane (20 mL) and treated with phenyl phosphodichloridate (1.51 mL, 10.15 mmol) at −78° C. under an atmosphere of argon. Diisopropylethylamine (2.6 mL, 20.27 mmol) was added dropwise. The mixture was stirred at −78° C. for 30 minutes, then allowed to warm to room temperature for 1 hr. The mixture was chilled to −5° C. and methyl pantothenate (1.6 mL, 20.27 mmol) was added dropwise in dichloromethane. N-methylimidazole (1.6 mL, 20.27 mmol) was added, and after stirring at −5° C. for 30 mins and room temperature for 1 hour, 2 mL of methanol was added. The mixture was washed sequentially with water (30 mL), 5% citric acid (30 mL), and brine (10 mL). The organic phase was dried (Na 2 SO 4 ) and the solvent was removed under reduced pressure. Purification was achieved with a 1:1 mixture of EtOAc:hexane to afford the product as a clear colorless oil. (1.1 g, 24% yield). HPLC showed the product, as a 1:1 mixture of disastereomers, having a purity of 97%. 1 H NMR (300 MHz, CDCl 3 ): δ 1.11 (s, 3H, CH 3 ), 1.27, 1.39 and 1.40 (2 Ss, 3H, CH 3 ), 1.41 (overlapping d, 3H, J=1.2 Hz, CHCH 3 ), 3.55 (m, 2H, CH 2 ), 3.60 (m, 1H, CH 2 ), 3.63 (m, 1H, CH), 3.66 and 3.68 (2 Ss, 3H, COCH 3 ), 3.70 and 3.74 (2 Ss, 3H, COCH 3 ), 3.78 (m, 1H CH), 4.03 (m, 1H, CH), 4.17 (m, 1H, CH), 7.16 and 7.35 and 7.40 (2 Ms, 5H, Ph). Expected Mol. Wt. 474.18, Observed Mol. Wt. 475.03 (M+H + ].
Examples 3-14
[0108] The compounds shown in the table below were prepared according to the synthetic procedures outlined in Examples 1 and 2, using the appropriate starting materials.
[0000]
Mass
Observed
Isolated
Purity
Expected
Mol. Wt.
Example
R (Amino Acid)
R′
R″
(g)
(%)
Mol. Wt.
[M + H + ]
3
Me (L-Ala)
n-Bu
n-Bu
0.34
91
558.27
559.24
4
Me (L-Ala)
Bn
Et
1.87
97
564.22
565.07
5
Me (L-Ala)
Et
Bn
1.36
97
564.22
565.14
6
Me (L-Ala)
Bn
Bn
1.38
98
626.24
627.32
7
Me (L-Ala)
MeCyPr
MeCyPr
1.77
100
554.24
555.23
8
H (Gly)
Bn
Et
0.44
93
550.21
551.02
9
i-Pr (L-Val)
Et
Et
0.39
94
530.24
531.14
10
MeIndole (L-Trp)
Me
Me
1.43
95
589.22
590.16
11
MeIndole (L-Trp)
Et
Et
0.45
95
617.25
618.21
12
MeIndole (L-Trp)
Bn
Et
0.47
91
679.27
680.17
13
MeIndole (L-Trp)
Et
Bn
1.33
95
679.27
680.17
14
MeIndole (L-Trp)
Bn
Bn
0.13
90
741.28
742.24
Example 15
In Vitro Bacterial Testing
[0109] SJ16 is a strain of Escherichia coli that requires addition of pantothenic acid to proliferate (i.e., it has a mutation such that pantothenic acid is inactive). Thus, it serves as a useful assay in determining whether a compound can rescue an organism deficient in PANK, the cause of PKAN. Compounds of the present invention were tested for toxicity and for the ability to support growth of Escherichia coli K-12 strains SJ16 (see, e.g., Jackowski et al., J. Bacteriol., 148, 926-932, 1981) and DV70 (see, e.g., Vallari et al., J. Bacteriol., 169, 5795-5800, 1987) under permissive and non-permissive conditions. The test compound in a solvent (dimethylsulfoxide, DMSO) was added to growth medium at a final concentration of 8 μM. Solvent alone (DMSO) was added to the growth medium at a final concentration ≦0.1% as a control.
[0110] Strain SJ16 was grown at 37° C. for 18 hours on a solid medium containing agar (1.5%), M9 minimal essential salts (see, Miller, Experiments in Molecular Genetics. Cold Spring Harbor Laboratory, Cold Spring Harbor, N. Y., 1972), glucose (0.4%), methionine (50 μg/ml), and with (permissive) or without (non-permissive) calcium pantothenate (1 μM). Lack of growth with calcium pantothenate supplementation indicated toxicity. Growth without calcium pantothenate supplementation indicated the ability of the bacteria to metabolize the compound to yield pantothenate or β-alanine
[0111] Strain DV70 was grown at 30° C. (permissive) or 42° C. (non-permissive) for 18 hours on solid medium containing agar (1.5%), M9 minimal essential salts, glucose (0.4%), methionine (50 μg/ml), and calcium pantothenate (1 μM). Lack of growth at 30° C. indicated toxicity. Growth at 42° C. indicated metabolism of the compound and subsequent conversion to coenzyme A by the bacteria.
[0112] SJ16 recovery results for the compounds of Examples 2, 5, 7 and 12 are shown in the Table below. A ‘Yes” result indicates that bacteria were alive after 18 hours. The compounds of Examples 2, 5, 7 and 12 did not result in recovery of the DV70 strain.
[0000]
SJ16
Example
DMSO Used
Recovery
2
<10%
Yes
5
>50%
Yes
7
>60%
Yes
12
>70%
Yes*
*test compound precipitated
Example 16
[0113] The compounds of Examples 2, 5, 7 and 12 were tested in immortalized human cells (HEK 293T). The amount of acetyl-CoA (the downstream result of PANK) following administration of the compounds of Examples 2, 5, 7 and 12 were measured by mass spectrometry. The results are shown in FIG. 1 .
[0114] As can be seen from FIG. 1 , treatment of HEK 293T cells with 200 μM of the compound of Example 2 afforded a 42% increase in acetyl CoA over baseline (p<0.0005). Treatment of HEK 293T cells with 20 μM of the compound of Example 7 afforded a 38% increase in acetyl CoA over baseline (p<0.005).
Example 17
In Vivo Testing
[0115] Compounds of the invention were tested for efficacy in Pank1 −/− mice (strain 129SvJ×C57BL/6J background) which were compared with age-matched Pank1 +/+ (strain 129SvJ×C57BL/6J) littermates, ages 8-12 weeks. Each mouse was identified with a coded ear tag and weighed on the first day of testing. Each compound was administered to 4-5 mice by intraperitoneal injection at a dose of 1.2 μmoles/g body weight in 5 μL dimethylsulfoxide once daily for 5 days, and mice were then fasted overnight, weighed and euthanized. Untreated mice received 5 μL dimethylsulfoxide once daily for 5 days and then were fasted overnight prior to weighing and euthanasia. Livers were excised from each mouse, aliquots were snap-frozen in liquid nitrogen, and stored at −80° C. Within 7 days, liver samples were thawed on ice, weighed and analyzed for coenzyme A content as described below. Efficacy was indicated by a statistically significant increase in the liver Coenzyme A levels in the Pank1 −/− mice as compared to the liver from untreated Pank1 −/− mice and by equivalence in comparison with Coenzyme A levels in untreated Pank1 +/+ mice.
CoA Measurements: Extraction of Fibroblasts and Liver and Derivatization of Coenzyme A Prior to High Pressure Liquid Chromatography (HPLC)
[0116] Extraction of fibroblasts or liver was performed by modification of a method described previously (see, Minkler et al., Anal. Biochem., 376, 275-276, 2008). Coenzyme A derivatization was performed by modification of a method described previously (see, Shimada et al., J. Chromatogr. B Biomed. Appl., 659, 227-241, 1994).
[0117] Liver (20-50 mg) was homogenized in 2 mL of 1 mM KOH, and the pH was adjusted to 12 with 0.25 M KOH. Fibroblasts were scraped off the culture dish and collected in 1 mL of water, which was transferred to 200 μL of 0.25 M NaOH. The liver homogenate was then incubated at 55° C. for 2 hours and the fibroblast cells were incubated for 1 hour at 55° C. The pH was adjusted to pH 8 with 1 M Trizma-HCl, and 10 μL of 100 mM monobromobimane (mBBr, Life Technologies, NY) was added for 2 hours in the dark. The reaction was acidified with acetic acid, and centrifuged at 500 g for 15 minutes. The supernatant was then added to a 2-(2-pyridyl)ethyl column (Supelco) which was equilibrated with 1 mL of 50% methanol/2% acetic acid. The column was washed with 2×1 mL 50% methanol/2% acetic acid and 1 mL water. Samples were eluted with 2×1 mL 50 mM ammonium formate in 95% ethanol. Samples were evaporated under nitrogen and resuspended in 300 μL of water. Samples were spun through a Spin-X Centrifuge Tube Filter (0.22 μm Cellulose Acetate, Costar) to remove any precipitants before HPLC.
Coenzyme A Quantification by HPLC
[0118] The mBBr derivative of Coenzyme A was separated by reverse-phase HPLC using a Gemini C 18 3 μm column (150×4.60 mm) from Phenomenex (Torrance, Calif.). The chromatography system used was a Waters e2695 separation module with a UV/Vis detector and controlled by the Empower 3 software. Solvent A was 50 mM potassium phosphate pH 4.6, and solvent B was 100% acetonitrile. 20 μL of sample was injected onto the column, and the flow rate was 0.5 mL/min. The HPLC program was the following: starting solvent mixture of 90% A/10% B, 0 to 2 min isocratic with 10% B, 2 to 9 min linear gradient from 10% B to 25% B, 9 to 23 min concave gradient from 25% B to 40% B, 23 to 25 min linear gradient from 40% to 10%, and 25 to 30 min isocratic with 10% B. The detector was set at λ393 nm. The area under the mBBr derivatized Coenzyme A peak was integrated and was compared to a standard concentration curve of mBBr-Coenzyme A prepared from commercial Coenzyme A.
[0119] FIG. 2 depicts levels of mBBr CoA in PANK knockout mice following administration of the compound of Example 2. As can be seen from FIG. 2 , the compound of Example 2 restored levels of CoA to those seen in normal mice. This is also shown in the Table below.
[0000]
pmol mBBR-CoA/
mg Liver
Mean
SEM
n
WT
522.545
18.279
4
pank1 KO
339.560
11.496
5
pank 1 KO +
563.358
44.959
5
Example 2
[0120] All publications, patents, and patent applications cited herein are hereby incorporated by reference.
|
The present disclosure relates to pantothenate derivatives for the treatment of neurologic disorders (such as pantothenate kinase-associated neurodegeneration), pharmaceutical compositions containing such compounds, and their use in treatment of neurologic disorders.
| 2
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to electrospinning of fibers and more particularly to controlled electrospinning of fibers.
2. Background Art
Electrospinning has been known, since the 1930's. However, electrospinning of fibers has not previously gained significant industrial importance, owing to a variety of issues, some of these having been low output, inconsistent and low molecular orientation, poor mechanical properties, difficulties and instabilities of fluid streams in forming fibers, and high diameter distribution of the electrospun fibers. Although special needs of military, medical and filtration applications have stimulated recent studies and renewed interest in the electrospinning, quantitative technical and scientific information regarding process and product characterization are extremely limited.
In a typical electrospinning system, a charged polymer solution (or melt) is fed through a small opening or orifice of a nozzle (usually a needle or pipette tip), and because of its charge, the polymer solution is drawn (as a jet) toward a collector, which is often a grounded collecting plate (usually a metal screen, plate, or rotating mandrel), typically 5-30 cm from the orifice of the nozzle. During the jet's travel, the solvent gradually evaporates, and a charged polymer fiber is left to accumulate on the grounded target. The charge on the fibers eventually dissipates into the surrounding environment. The resulting product is a non-woven fiber mat that is composed of tiny fibers with diameters between 50 nanometers and 10 microns. This non-woven mat forms the foundation of a “scaffold”. If the target is allowed to move with respect to the nozzle position, specific fiber orientations (parallel alignment or a random) can be achieved. Previous work has shown that varying the fiber diameter and orientation can vary the mechanical properties of the scaffold.
Using electrical forces alone, electrospinning can produce fibers with nanometer diameters. Electrospun fibers have large surface to volume ratios, because of their small diameters, which enable them to absorb more liquids than do fibers having large diameters, and small pore sizes make them suitable candidates for military and civilian filtration applications. It is expected that electrospun fibers will find many applications in composite materials and as reinforcements.
Typically, an electric field is used to draw a positively charged polymer solution from an orifice of a nozzle to a collector, and “electrospin” the polymer solution, as the polymer solution travels from the orifice to the collector. A jet of solution typically flows or travels from the orifice of the nozzle to the collector, which is typically grounded. The jet emerges from the nozzle, which is typically of a conical geometry, and often, in particular, a Taylor cone. The jet transitions to form a stretched jet, after the jet leaves the orifice of the nozzle, and then the jet divides into many fibers in an area called the “splaying region”.
As the ionized jet of positively charged polymer solution travels from the orifice to the collector, a “whipping motion” (or bending instability) results in the jet
There is thus a need for apparatus and methods that control the jet and minimize instabilities of the jet as it travels from the nozzle to the collector plate. The apparatus and methods should be capable of controlling the jet, the path of the jet, controlling and minimizing instabilities of these fluid streams during formation of fibers, and controlling the direction of the jet and concentration of solution during electrospinning.
The formation of fibers by electrospinning is also impacted by the viscosity of spinnable fluids, since some spinnable fluids are so viscous that they require higher forces than electric fields can typically produce without arcing, i.e., dielectric breakdown of the air. Likewise, these techniques have been problematic where high temperatures are required, since high temperatures typically increase the conductivity of structural parts and complicate the control of high strength electrical fields. The apparatus and methods should, thus, also be capable of controlling the jet and minimizing instabilities for fluids of different viscosities, and should be capable of controlling the jet during the use of extreme temperatures and high strength electrical fields.
The apparatus and methods that control and minimize instabilities of the jet should be capable of improving efficiency, productivity, and economy of the electrospinning process. The apparatus and methods should also be capable of more accurate use of fluids, improvements in production and formation of fibers, and improvements in the production rate, fiber diameter distribution, measure, and characterization of the electrospun fiber properties in terms of size, orientation and mechanical properties.
Different electrospinning apparatus and methods have heretofore been known. However, none of the electrospinning apparatus and methods adequately satisfies these aforementioned needs.
U.S. Pat. No. 6,713,011 (Chu, et al.) discloses an apparatus and method for electrospinning polymer fibers and membranes. The method includes electrospinning a polymer fiber from a conducting fluid in the presence of a first electric field established between a conducting fluid introduction device and a ground source and modifying the first electric field with a second electric field to form a jet stream of the conducting fluid. The method also includes electrically controlling the flow characteristics of the jet stream, forming a plurality of electrospinning jet streams and independently controlling the flow characteristics of at least one of the jet streams. The apparatus for electrospinning includes a conducting fluid introduction device containing a plurality of electrospinning spinnerets, a ground member positioned adjacent to the spinnerets, a support member disposed between the spinnerets and the ground member and movable to receive fibers formed from the conducting fluid, and a component for controlling the flow characteristics of conducting fluid from at least one spinneret independently from another spinneret. U.S. Pat. No. 4,689,186 (Bornat) discloses production of electrostatically spun products, comprising electrostatically spinning a fiberizable liquid, the electrostatic field being distorted by the presence of an auxiliary electrode, preferably so as to encourage the deposition of circumferential fibers, having tubular portions. U.S. Pat. No. 6,520,425 (Reneker) discloses a process and apparatus for the production of nanofibers, in which a nozzle is used for forming nanofibers by using a pressurized gas stream comprises a center tube, a first supply tube that is positioned concentrically around and apart from the center tube, a middle gas tube positioned concentrically around and apart from the first supply tube, and a second supply tube positioned concentrically around and apart from the middle gas tube. The center tube and first supply tube form a first annular column. The middle gas tube and the first supply tube form a second annular column. The middle gas tube and second supply tube form a third annular column. The tubes are positioned, so that first and second gas jet spaces are created between the lower ends of the center tube and first supply tube, and the middle gas tube and second supply tube, respectively. A method for forming nanofibers from a single nozzle is also disclosed. U.S. Pat. No. 6,641,773 (Kleinmeyer, et al.) discloses electro spinning of submicron diameter polymer filaments, in which an electro spinning process yields substantially uniform, nanometer diameter polymer filaments. A thread-forming polymer is extruded through an anodically biased die orifice and drawn through an anodically biased electrostatic field. A continuous polymer filament is collected on a grounded collector. The polymer filament is linearly oriented and uniform in quality. The filament is particularly useful for weaving body armor, for chemical/biological protective clothing, as a biomedical tissue growth support, for fabricating micro sieves and for microelectronics fabrication. U.S. Pat. No. 6,991,702 (Kim) discloses an electrospinning apparatus, including a spinning dope main tank, a metering pump, a nozzle block, a collector positioned at the lower end of the nozzle block for collecting spun fibers, a voltage generator, a plurality of units for transmitting a voltage generated by the voltage generator to the nozzle block and the collector, the electrospinning apparatus containing a spinning dope drop device positioned between the metering pump and the nozzle block the spinning dope drop device having (i) a sealed cylindrical shape, (ii) a spinning dope inducing tube and a gas inletting tube for receiving gas through its lower end and having its gas inletting part connected to a filter aligned side-by-side at the upper portion of the spinning dope drop device, (iii) a spinning dope discharge tube extending from the lower portion of the spinning dope drop device and (iv) a hollow unit for dropping the spinning dope from the spinning dope inducing tube formed at the middle portion of the spinning dope drop device. U.S. Pat. No. 6,989,125 (Boney, et al.) discloses a process of making a nonwoven web, resulting in continuous fiber nonwoven webs with high material formation uniformity and MD-to-CD balance of fiber directionality and material properties, as measured by a MD:CD tensile ratio of 1.2 or less, and laminates of the nonwoven webs. The invention also includes a method for forming the nonwoven webs, wherein a fiber production apparatus is oriented at an angle less than 90 degrees to the MD direction, and the fibers are subjected to deflection by a deflector oriented at an angle B, with respect to the centerline of the fiber production apparatus, where B is about 10 to about 80 degrees. U.S. Pat. No. 4,233,014 (Kinney) discloses a process and apparatus for forming a non-woven web in which a bundle of untwisted filaments are charged upstream of a pair of elastomer covered counter rotating squeeze rolls and propelled through the nip of the rolls to a moving laydown belt, with the assistance of an electrostatic field developed between the rolls and the belt. U.S. Pat. No. 6,616,435 (Lee, et al.) discloses an electrospinning method and apparatus for manufacturing a porous polymer web, which includes the steps of: forming, pressurizing and supplying at least one or more kinds of polymer materials in a liquid state; and discharging and piling the polymer materials to a collector through one or more charged nozzles, the collector being located under the nozzles and charged to have a polarity opposing the polarity of the charged nozzles, the collector moving at a prescribed speed. U.S. Pat. No. 5,744,090 (Jones, et al.) discloses a process for the manufacture of conductive fibers, usable in electrostatic cleaning devices, in which the conductive fiber is formed from a mixture, including at least one fiber forming material and conductive magnetic materials, and the conductive magnetic materials are migrated toward the periphery of the fiber by application of a magnetic field to the fiber. The conductive fibers having the conductive magnetic materials located at the periphery of the fiber are preferably incorporated into an electrostatic cleaning device for use in an electrostatographic printing device. U.S. Pat. No. 5,817,272 (Frey, et al.) discloses a process of making a biocompatible porous hollow fiber that is made of polyolefin material and is coated with a biocompatible carbon material is disclosed. The biocompatible hollow fiber produced can be used as exchange material, diaphragms and/or semipermeable membranes within devices, which will contact blood or plasma outside of the living body. The coated fiber is produced by introducing a preformed porous hollow fiber into an atmosphere of gaseous monomer vinylidene chloride and subsequent induction, e.g. by gamma radiation, of a graft-polymerization reaction to form a uniform polyvinylidene chloride layer. The ultimate coating is formed after a dehydrochlorination reaction in which hydrogen chloride is removed from the layer. The dechlorination reaction is typically performed by treating the fiber with hot concentrated aqueous ammonia solution. The reaction can be continued to reduce the chlorine content of the coating to less than 6% of its original value. U.S. Pat. No. 6,858,168 (Vollrath, et al.) discloses an apparatus and method for forming a liquid spinning solution into a solid formed product, whereby the solution is passed through at least one tubular passage, having walls formed at least partly of semipermeable and/or porous material. The semipermeable and/or porous material allows certain parameters, such as the concentration of hydrogen ions, water, salts and low molecular weight, of the liquid spinning solution to be altered as the spinning solution passes through the tubular passage(s). U.S. Pat. No. 6,444,151 (Nguyen, et al.) discloses an apparatus and process for spinning polymeric filaments, in which a melt spinning apparatus for spinning continuous polymeric filaments, includes a first stage gas inlet chamber adapted to be located below a spinneret and optionally a second stage gas inlet chamber located below the first stage gas inlet chamber. The gas inlet chambers supply gas to the filaments to control the temperature of the filaments. The melt spinning apparatus also includes a tube located below the second stage gas inlet chamber, for surrounding the filaments as they cool. The tube may include an interior wall having a converging section, optionally followed by a diverging section. U.S. Pat. No. 6,110,590 (Zarkoob, et al.) discloses synthetically spun silk nanofibers and a process for making the same, in which a silk nanofiber composite network is produced by forming a solution of silk fiber and hexafluroisopropanol, wherein the step of forming is devoid of any acid treatment, where the silk solution has a concentration of about 0.2 to about 1.5 weight percent silk in hexafluroisopropanol, and where the silk is selected from Bombyx mori silk and Nephila clavipes silk; and electrospinning the solution, thereby forming a non-woven network of nanofibers having a diameter in the range from about 2 to about 2000 nanometers. U.S. Pat. No. 6,265,466 (Glatkowski, et al.) discloses an electromagnetic shielding composite having nanotubes and a method of making the same. According to one embodiment, the composite for providing electromagnetic shielding includes a polymeric material and an effective amount of oriented nanotubes for EM shielding, the nanotubes being oriented when a shearing force is applied to the composite. According to another embodiment of the invention, the method for making an electromagnetic shielding includes the steps of (1) providing a polymer with an amount of nanotubes, and (2) imparting a shearing force to the polymer and nanotubes to orient the nanotubes. U.S. Pat. No. 6,656,394 (Kelly) discloses a method and apparatus for high throughput generation of fibers by charge injection, in which a fiber is formed by providing a stream of a solidifiable fluid, injecting the stream with a net charge, so as to disrupt the stream and allowing the stream to solidify to form fibers. U.S. Pat. Nos. 6,955,775 and 7,070,640 (Chung, et al.) disclose a process of making fine fiber material, including improved polymer materials and fine fiber materials, which can be made from the improved polymeric materials, in the form of microfiber and nanofiber structures. The microfiber and nanofiber structures can be used in a variety of useful applications including the formation of filter materials. U.S. Pat. No. 6,753,454 (Smith, et al.) discloses electrospun fibers and an apparatus therefor. A fiber comprising a substantially homogeneous mixture of a hydrophilic polymer and a polymer, which is at least weakly hydrophobic is disclosed. The fiber optionally contains a pH adjusting compound. A method of making the fiber comprises electrospinning fibers of the substantially homogeneous polymer solution. A method of treating a wound or other area of a patient requiring protection from contamination comprises electrospinning the substantially homogeneous polymer solution to form a dressing. An apparatus for electrospinning a wound dressing is disclosed. U.S. Pat. No. 5,911,930 (Kinlen, et al.) discloses solvent spinning of fibers containing an intrinsically conductive polymer, including a fiber containing an organic acid salt of an intrinsically conductive polymer distributed throughout a matrix polymer along, with a method for providing such fibers by spinning a solution, which includes an organic acid salt of an intrinsically conductive polymer, a matrix polymer, and a spinning solvent into a coagulation bath including a nonsolvent for both the organic acid salt of an intrinsically conductive polymer and the matrix polymer. The intrinsically conductive polymer-containing fibers typically have electrical conductivities below about 10.sup.−5 S/cm. U.S. Pat. No. 6,695,992 (Reneker) discloses a process and apparatus for the production of nanofibers, including an apparatus for forming a non-woven mat of nanofibers, by using a pressurized gas stream, which includes parallel, spaced apart, first, second, and third members, each having a supply end and an opposing exit end. The second member is located apart from and adjacent to the first member. The exit end of the second member extends beyond the exit end of the first member. The first and second members define a first supply slit. The third member is located apart from and adjacent to the first member on the opposite side of the first member from the second member. The first and third members define a first gas slit, and the exit ends of the first, second and third members define a gas jet space. A method for forming a non-woven mat of nanofibers utilizes this nozzle. U.S. Pat. No. 7,070,723 (Ruitenberg, et al.) discloses a method for spin-drawing of melt-spun yarns. A method is provided for simultaneous spin-drawing of continuous yarns consisting of one or more filaments, comprising the steps in which a melt of a thermoplastic material is fed to a spinning device, the melt is extruded through a spinneret, by means of extrusion openings with the formation of continuous yarns, the continuous yarns are cooled by feeding them through a first and a second cooling zone, wherein the continuous yarns are cooled essentially by a stream of air on passing through the first cooling zone and essentially by a fluid, consisting wholly or partly of a component that is liquid at room temperature, on passing through the second cooling zone, and the continuous yarns are then dried, subsequently drawn and wound up by means of winding devices, the method being distinguished in that the continuous yarns are fed through the first and second cooling zones at a speed of up to 500 m/min and that the residence time of the continuous yarns within the first cooling zone is at least 0.1 sec. U.S. Pat. No. 7,105,058 (Sinyagin) discloses an apparatus and method for forming a microfiber coating, which includes directing a liquid solution toward a deposition surface. The apparatus includes a tube defining a volume through which the liquid solution travels. An electric field is applied between the origin of the liquid solution and the surface. A gas is injected into the tube to create a vortex flow within the tube. This vortex flow protects the deposition surface from entrainment of ambient air from the surrounding atmosphere. U.S. Pat. No. 7,105,812 (Zhao, et al.) discloses a microfluidic chip with enhanced tip for stable electrospray ionization, in which a microfluidic chip is formed with multiple fluid channels terminating at a tapered electrospray ionization tip for mass spectrometric analysis. The fluid channels may be formed onto a channel plate that is in fluid communication with corresponding reservoirs. The electrospray tip can be formed along a defined distal portion of the channel plate that can include a single or multiple tapered surfaces. The fluid channels may terminate at an open-tip region of the electrospray tip. A covering plate may substantially enclose most portions of the fluid channels formed on the channel plate except for the open-tip region. Another aspect of the invention provides methods for conducting mass spectrometric analyses of multiple samples flowing through individual fluid channels in a single microfluidic chip that is formed with a tapered electrospray tip having an open-tip region. U.S. Pat. No. 5,296,172 (Davis, et al.) discloses an electrostatic field enhancing process and apparatus for improved web pinning and uniformity in a fibrous web forming operation. The improvements are achieved by imposing an auxiliary electrostatic field above the fibrous web as it is pinned along a moving collection surface. An auxiliary electrostatic field enhancing plate is positioned above the web and collection surface and downstream of the laydown position where the web initially is deposited on the collection surface. The plate enhances the electrostatic field in the region above the collection surface and thereby increases the web pinning forces. When the invention is applied to a flash-spinning process, where trifluorochloromethane is used as the fluid medium, an auxiliary electrostatic field of between about 2 and 80 kV/cm, preferably between about 10 and 60 kV/cm, is applied by the plate. U.S. Pat. No. 3,860,369 (Berthauer, et al.) and U.S. Pat. No. 3,851,023 (Berthauer, et al.) disclose apparatus for making non-woven fibrous sheet and a process for forming a web; U.S. Pat. No. 3,319,309 (Owens) discloses charged web collecting apparatus; and U.S. Pat. No. 3,689,608 (Hollbert, et al.) discloses a process for forming a nonwoven web. U.S. Pat. No. 4,965,110 (Berry) and U.S. Pat. No. 5,024,789 (Berry) disclose a method and apparatus for manufacturing an electrostatically spun structure; U.S. Pat. No. 4,044,404 (Martin, et al.) discloses a fibrillar lining for a prosthetic device prepared by electrostatically spinning an organic material and collecting the spun fibers on a receiver; and U.S. Pat. No. 3,169,899 (Steuber) discloses non woven fibrous sheet of continuous strand material and the method of making same. U.S. Pat. No. 7,105,124 (Choi) discloses a method, apparatus, and product for manufacturing nanofiber media; U.S. Pat. No. 7,081,622 (Kameoka, et al.) discloses an electrospray emitter for a microfluidic channel; U.S. Pat. No. 6,106,913 (Scardino, et al.) discloses fibrous structures containing nanofibrils and other textile fibers; U.S. Pat. No. 6,709,623 (Haynes, et al.) discloses a process of and apparatus for making a nonwoven web; and U.S. Pat. No. 6,790,528 (Wendroff, et al.) discloses production of polymer fibers having nanoscale morphologies. Reneker, D. H., Yarin, A. L., Fong, H., and Koombhongse, S., “Bending instability of electrically charged liquid jets of polymer solutions in electrospinning,” Journal of Applied Physics, 2000, 87, No 9, pp. 4531-4547 discloses bending instability of electrically charged liquid jets of polymer solutions in electrospinning. Nanofibers of polymers were electrospun by creating an electrically charged jet of polymer solution at a pendent droplet. After the jet flowed away from the droplet in a nearly straight line, the jet bent into a complex path and other changes in shape occurred, during which electrical forces stretched and thinned it by very large ratios. After the solvent evaporated, birefringent nanofibers were left. The reasons for the instability are analyzed and explained, using a mathematical model. The rheological complexity of the polymer solution is included, which allows consideration of viscoelastic jets. It is shown that the longitudinal stress caused by the external electric field acting on the charge carried by the jet stabilized the straight jet for some distance. Then a lateral perturbation grew in response to the repulsive forces between adjacent elements of charge carried by the jet. The motion of segments of the jet grew rapidly into an electrically driven bending instability. The three-dimensional paths of continuous jets were calculated, both in the nearly straight region, where the instability grew slowly and in the region where the bending dominated the path of the jet. The mathematical model provides a reasonable representation of the experimental data, particularly of the jet paths determined from high speed videographic observations Warner, S. B., Buer, A., Grimler, M., Ugbolue, S. C., Rutledge, G. C. and Shin, M. Y., “A Fundamental Investigation of the Formation and Properties of Electrospun Fibers”, National Textile Center Annual Report, 1998 discusses the fundamental engineering science and technology of electrostatic fiber production (“electrospinning”). Electrospinning and its capabilities for producing novel synthetic fibers of unusually small diameter and good mechanical performance (“nanofibers”), and fabrics with controllable pore structure and high surface area are discussed. The following items are included: design and construction of process equipment for controllable and reproducible electrospinning; clarification of the fundamental electrohydrodynamics of the electrospinning process and, correlation to the polymer fluid characteristics; characterization and evaluation of the fluid instabilities postulated to be crucial for producing ultrafine diameter fibers; characterization of the morphology and material properties of electrospun polymer fibers; development of techniques for generating oriented fibers and yarns by the electrospinning process; and productivity improvement of the electrospinning process.
For the foregoing reasons, there is a need for apparatus and methods that control the jet and minimize instabilities of the jet as it travels from the nozzle to the collector plate. The apparatus and methods should be capable of controlling the jet, the path of the jet, and the concentration of solution during electrospinning.
The apparatus and methods should also be capable of controlling the jet and minimizing instabilities for fluids of different viscosities, and should be capable of controlling the jet, during the use of extreme temperatures and high strength electrical fields.
The apparatus and methods that control and minimize instabilities of the jet should be capable of improving efficiency, productivity, and economy of the electrospinning process. The apparatus and methods should also be capable of more accurate use of fluids, improvements in production and formation of fibers, and improvements in the production rate, fiber diameter distribution, measure, and characterization of the electrospun fiber properties in terms of size, orientation and mechanical properties.
SUMMARY
The present invention is directed to electrospinning apparatus and methods that control a jet or jets of solution during the electrospinning process. The apparatus and methods minimize instabilities of the jet(s) as it travels from the nozzle to the collector plate. The apparatus and methods are capable of controlling the jet(s), the path of the jet(s), and the concentration of solution during electrospinning.
The apparatus and methods are also capable of controlling the jet(s) and minimizing instabilities for fluids of different viscosities, and are capable of controlling the jet(s), during the use of extreme temperatures and high strength electrical fields.
The apparatus and methods that control and minimize instabilities of the jet(s) are also capable of improving efficiency, productivity, and economy of the electrospinning process. The apparatus and methods are capable of more accurate use of fluids, improvements in production and formation of fibers, and improvements in the production rate, fiber diameter distribution, measure, and characterization of the electrospun fiber properties in terms of size, orientation and mechanical properties.
An electrospinning apparatus for spinning a polymer fiber from a fluid comprising a polymer having features of the present invention comprises: at least one collector; a jet supply device delivering a quantity of fluid; the jet supply device in electrical communication with the at least one collector, the jet supply device and the at least one collector adapted to form an electric field therebetween and direct the quantity of fluid from the jet supply device toward the at least one collector; at least one magnet forming a magnetic field between the at least jet supply device and the at least one collector; the at least one collector drawing the quantity of fluid toward the at least one collector and forming the quantity of fluid into at least one polymer fiber at the at least one collector of the plurality of collectors; the magnet controlling dispersion characteristics of the quantity of fluid.
An electrospinning method for spinning a polymer fiber from a fluid comprising a polymer in the presence of an electric field established between at least one collector and a jet supply device, having features of the present invention comprises: a) forming an electrospinning jet stream of the fluid directed toward the at least one collector; b) controlling dispersion characteristics of the fluid by applying a magnetic field between the jet supply device and the at least one collector; c) forming at least one polymer fiber at the at least one collector.
Another electrospinning apparatus for spinning a polymer fiber from a fluid comprising a polymer having features of the present invention comprises: a plurality of collectors; a jet supply device delivering a quantity of fluid; the jet supply device in electrical communication with the plurality of collectors, the jet supply device and the plurality of collectors adapted to form an electric field therebetween and direct the quantity of fluid from the jet supply device toward the plurality of collectors; a controller controlling dispersion characteristics of the quantity of fluid by applying different voltages to at least two collectors of the plurality of collectors and influencing the electric field; at least one collector of the plurality of collectors drawing the quantity of fluid toward the at least one collector and forming the quantity of fluid into at least one polymer fiber at the at least one collector of the plurality of collectors. Another electrospinning method for spinning a polymer fiber from a fluid comprising a polymer in the presence of an electric field established between a plurality of collectors and a jet supply device having features of the present invention comprises: a) forming an electrospinning jet stream of the fluid directed toward the plurality of collectors; b) controlling dispersion characteristics of the fluid by applying different voltages to at least two collectors of the plurality of collectors; c) forming at least one polymer fiber at least one collector of the plurality of collectors.
DRAWINGS
These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:
FIG. 1 is a schematic representation of an electrospinning apparatus, having electric field control using different collector voltages, constructed in accordance with the present invention;
FIG. 2 is a schematic representation of an alternate embodiment of an electrospinning apparatus, having electric field control using different collector voltages and transverse electric field control of a jet of the electrospinning apparatus;
FIG. 3 is a schematic representation of an alternate embodiment of an electrospinning apparatus, having transverse magnetic field control of a jet of the electrospinning apparatus;
FIG. 4 is a schematic representation of an alternate embodiment of an electrospinning apparatus, having magnetic focusing control of a jet of the electrospinning apparatus;
FIG. 5 is a schematic representation of an alternate embodiment of an electrospinning apparatus, having magnetic induction control of a jet of the electrospinning apparatus;
FIG. 6 is a schematic representation of an alternate embodiment of an electrospinning apparatus, having transverse magnetic field control and transverse electric field control of a jet of the electrospinning apparatus;
FIG. 7 is a perspective view of an alternate embodiment of an electrospinning apparatus, having transverse magnetic field control and transverse electric field control of a jet of the electrospinning apparatus;
FIG. 8 is a schematic representation of an alternate embodiment of an electrospinning apparatus, having magnetic bending control of a jet of the electrospinning apparatus; and
FIG. 9 is a schematic representation of an alternate embodiment of an electrospinning apparatus, having alternate magnetic bending control of a jet of the electrospinning apparatus.
DESCRIPTION
The preferred embodiments of the present invention will be described with reference to FIGS. 1-9 of the drawings. Identical elements in the various figures are identified with the same reference numbers.
During electrospinning, typically, an electric field is used to draw a positively charged polymer solution from an orifice of a nozzle to a collector, and “electrospin” the polymer solution, as the polymer solution travels from the orifice to the collector. A jet of solution typically flows or travels from the orifice of the nozzle to the collector, which is typically grounded. The jet emerges from the nozzle, which is typically of a conical geometry, and often, in particular, a Taylor cone. The jet transitions to form a stretched jet, after the jet leaves the orifice of the nozzle, and then the jet divides into many fibers in an area called the “splaying region”.
As the ionized jet of positively charged polymer solution travels from the orifice to the collector, a “whipping motion” (or bending instability) results in the jet.
As the ionized jet of positively charged polymer solution travels from the orifice of the jet to the collector, a magnetic field is induced, which creates the whipping motion (or bending instability) of the jet. The magnetic field is induced by the motion of the charged polymer solution, or in other words, by the motion of charged particles of the polymer solution.
The whipping motion (or bending instability) may be controlled by controlling the magnetic field in the vicinity of the jet and/or controlling the electric field in the vicinity of the jet.
FIG. 1 shows an embodiment of the present invention, an electrospinning apparatus 10 , which controls whipping motion of a jet 12 of charged polymer solution, hereinafter designated as the jet 12 , during electrospinning of polymer fibers 14 . The electrospinning apparatus 10 has jet supply device 16 , which has reservoir 18 having polymer solution 20 therein and mixer 22 for mixing the polymer solution 20 , electrode 24 , pump 25 for pumping the polymer solution 20 from the reservoir 18 , and orifice 26 for discharging the jet 12 from the jet supply device 16 . The electrospinning apparatus 10 has collectors 28 , 30 , 32 , 34 , and 36 for collecting the polymer fibers 14 , power source 38 , and voltage controller 40 , the power source 38 in electrical communication with and supplying power to the electrode 24 and the voltage controller 40 . The voltage controller 40 is in electrical communication with and provides power to each of the collectors 28 , 30 , 32 , 34 , and 36 , voltages V 1 ( 42 ), V 2 ( 44 ), V 3 ( 46 ), V 4 ( 48 ), and V 5 ( 50 ) to each of the collectors 28 , 30 , 32 , 34 , and 36 . The potential difference between the collectors 28 , 30 , 32 , 34 , and 36 and the electrode 24 draws the jet 12 from the jet supply device 16 toward the collectors 28 , 30 , 32 , 34 , and 36 , the polymer fibers 14 being formed, upon approaching the collectors 28 , 30 , 32 , 34 , and 36 , and collected at the collectors 28 , 30 , 32 , 34 , and 36 . At least two of the voltages V 1 ( 42 ), V 2 ( 44 ), V 3 ( 46 ), V 4 ( 48 ), and V 5 ( 50 ) at the collectors 28 , 30 , 32 , 34 , and 36 are set to be different from each other, as a means of controlling the electric fields between the electrode 24 and each of the collectors 28 , 30 , 32 , 34 , and 36 , and, thus, controlling the whipping motion of the jet 12 and stabilizing bending motion of the jet 12 . The voltage controller 40 , thus, may be used to focus the jet 12 , which typically travels from the orifice 26 in a rapidly rotating spiral motion. The electrospinning apparatus 10 uses electrostatic focusing. The dispersion of the jet 12 is controlled by controlling the electric field in the vicinity of the jet 12 of the electrospinning apparatus 10 .
FIG. 2 shows an alternate embodiment of the present invention, an electrospinning apparatus 100 , which controls whipping motion of a jet 112 of charged polymer solution, hereinafter designated as the jet 112 , during electrospinning of polymer fibers 114 , which is substantially the same as the electrospinning apparatus 10 , except that the electrospinning apparatus 100 has electrodes 116 and 118 , in communication with and powered by power source 120 , which generates an electric field between the electrodes 116 and 118 substantially transverse to the jet 112 and further aids in controlling whipping motion of the jet 112 and stabilizing bending motion of the jet 112 . The electrospinning apparatus 100 also has voltage controller 121 to control voltages V 1 ( 122 ), V 2 ( 124 ), V 3 ( 126 ), V 4 ( 128 ), and V 5 ( 130 ) at each of collectors 132 , 134 , 136 , 138 , and 140 , and voltage controllers 142 and 144 to control the voltages at the electrodes 116 and 118 , and control the whipping motion of the jet 112 and stabilize bending motion of the jet 112 . Power to the voltage controllers 121 , 142 , and 144 is supplied by the power source 120 . The electrospinning apparatus 100 uses electrostatic focusing. Controlling the electric fields between the electrodes 116 and 118 and each of the collectors 132 , 134 , 136 , 138 , and 140 and the electric field generated between the electrodes 116 and 118 , which the jet 112 passes through and which also impacts the jet 112 , further enhances the ability of the electrospinning apparatus 110 to control the whipping motion of the jet 112 and stabilize the bending motion of the jet 112 .
FIG. 3 shows an alternate embodiment of the present invention, an electrospinning apparatus 200 , which controls whipping motion of a jet 212 of charged polymer solution, hereinafter designated as the jet 212 , during electrospinning of polymer fibers 214 . The electrospinning apparatus 200 has jet supply device 216 , which has reservoir 218 having polymer solution 220 therein and mixer 222 for mixing the polymer solution 220 , electrode 224 , pump 225 for pumping the polymer solution 220 from the reservoir 218 , and orifice 226 for discharging the jet 212 from the jet supply device 216 . The electrospinning apparatus 200 has magnets 228 and 230 , which generate a magnetic field substantially transverse to the jet 212 , which are preferably electromagnets and offer control of the magnetic field generated between the magnets 228 and 230 . The electrospinning apparatus 200 has collectors 232 , 234 , and 236 for collecting the polymer fibers 214 , power source 238 in electrical communication with and supplying power to the magnets 228 and 230 , and power source 240 in electrical communication with and supplying power to the electrode 224 and the collectors 232 , 234 , and 236 . The electrospinning apparatus 200 uses magnetic focusing. The electrospinning apparatus 200 also has voltage controller 242 for regulating voltage to the collectors 232 , 234 , and 236 , if desired. The dispersion of the jet 212 is controlled by controlling the magnetic field in the vicinity of the jet 212 of the electrospinning apparatus 200 .
FIG. 4 shows an alternate embodiment of the present invention, an electrospinning apparatus 300 , which controls whipping motion of a jet 312 of charged polymer solution, hereinafter designated as the jet 312 , during electrospinning of polymer fibers 314 . The electrospinning apparatus 300 has jet supply device 316 , which has reservoir 318 having polymer solution 320 therein and mixer 322 for mixing the polymer solution 320 , electrode 324 , pump 325 for pumping the polymer solution 320 from the reservoir 318 , and orifice 326 for discharging the jet 312 from the jet supply device 316 . The electrospinning apparatus 300 has an electromagnet 328 about the jet 312 , for controlling the dispersion of the jet 312 . The electrospinning apparatus 300 has collectors 332 , 334 , and 336 for collecting the polymer fibers 314 , power source 338 in electrical communication with and supplying power to the electromagnet 328 , and power source 340 in electrical communication with and supplying power to the electrode 324 and the collectors 332 , 334 , and 336 . The electrospinning apparatus 300 uses magnetic focusing. The dispersion of the jet 312 is controlled by controlling the magnetic field developed by the electromagnet 328 in the vicinity of the jet 312 of the electrospinning apparatus 300 . The electromagnet 328 typically comprises a toroid having a high permeability magnetic core and a conductive winding thereabout although other suitable construction may be used.
FIG. 5 shows an alternate embodiment of the present invention, an electrospinning apparatus 400 , which is substantially the same as the electrospinning apparatus 300 , except that the electrospinning apparatus 400 , has helical coil 410 , which induces a magnetic field in the vicinity of the jet 412 , and controls the dispersion of the jet 412 .
FIG. 6 shows an alternate embodiment of the present invention, an electrospinning apparatus 450 , which is substantially the same as the electrospinning apparatus 200 , except that the electrospinning apparatus 450 controls the electric field generated between electrodes 452 and 454 , which is substantially transverse to jet 456 and is controlled by voltage controllers 455 and 457 , in addition to controlling the magnetic field generated by magnets 458 and 459 , which is also substantially transverse to the jet 456 . The dispersion of the jet 456 is controlled by controlling the magnetic field and the electric field in the vicinity of the jet 456 of the electrospinning apparatus 450 .
FIG. 7 is a perspective view of an alternate embodiment of the present invention, an electrospinning apparatus 460 , which is substantially the same as the electrospinning apparatus 450 , except that the electrospinning apparatus 460 has electrodes 464 and 466 and magnets 468 and 470 , the electrodes 464 and 466 opposing one another and located in substantially the same plane as the magnets 468 and 470 , which are also opposing one another, the electrodes 464 and 466 substantially perpendicular to the magnets 468 and 470 , respectively.
In the present invention, the electrospinning apparatus 460 is having transverse magnetic field control and transverse electric field control of a jet of the electrospinning apparatus 460 .
FIG. 8 shows an alternate embodiment of the present invention, an electrospinning apparatus 500 , which controls whipping motion of a jet 512 of charged polymer solution, hereinafter designated as the jet 512 , during electrospinning of polymer fibers 514 . The electrospinning apparatus 500 has jet supply device 516 , which has reservoir 518 having polymer solution 520 therein and mixer 522 for mixing the polymer solution 520 , electrode 524 , pump 525 for pumping the polymer solution 520 from the reservoir 518 , and orifice 526 for discharging the jet 512 from the jet supply device 516 . The electrospinning apparatus 500 has collector 532 for collecting the polymer fibers 514 , power source 538 in electrical communication with and supplying power to voltage controller 539 , which is in electrical communication with and supplying power to the electrode 524 and the collector 532 . The electrospinning apparatus 500 has magnet 534 , which generates a substantially constant uniform magnetic field represented by flux lines 536 , and which results in the jet 512 taking a substantially circular path through bending zone 537 at a substantially constant speed. The electrospinning apparatus 500 also has magnet deflection yoke 540 , which aids in magnetic focusing and further directs the jet 512 toward the collector 532 , the magnetic deflection yoke preferably being similar in construction to the electromagnet 328 of the electrospinning apparatus 300 , although other suitable construction may be used. The electrospinning apparatus 500 uses magnetic focusing. The dispersion of the jet 512 is controlled by controlling the magnetic flux lines developed by the magnet 534 in the bending zone 537 and the magnetic field developed by the magnetic deflection yoke 540 in the vicinity of the jet 512 of the electrospinning apparatus 500 . It should be noted that the jet 512 is deflected by substantially 180 degrees after exiting the orifice 526 by the time the jet arrives at the collector 532 , although other suitable angles may be used, such as, for example, 90 degrees, 270 degrees, or any other suitable angles.
FIG. 9 shows an alternate embodiment of the present invention, an electrospinning apparatus 600 , is similar to the electrospinning apparatus 500 , i.e., the electrospinning apparatus 600 has a plurality of magnets 610 , 612 , 614 , and 616 , which bend jet 620 repeatedly. The jet 620 is discharged from jet supply device 622 , which has orifice 623 , and travels through flux lines 624 , 626 , 628 , and 630 generated by the magnets 610 , 612 , 614 , and 616 , respectively. The electrospinning apparatus 600 has collector 632 for collecting polymer fibers 634 , power source 638 in electrical communication with and supplying power to voltage controller 640 , which is in electrical communication with and supplying power to the collector 632 and electrode 642 of the jet supply device 622 . The jet 620 is drawn from orifice 623 of the jet supply device 622 through bending zones 644 , 646 , 648 , and 650 to the collector 632 , the bending zones 644 , 646 , 648 , and 650 being similar to that of the bending zone 537 of the electrospinning apparatus 500 , except that the angles of the bending zones 644 , 646 , 648 , and 650 are each selected to be approximately 90 or 270 degrees. The electrospinning apparatus 600 uses magnetic focusing. The dispersion of the jet 620 is controlled by controlling the magnetic flux lines developed by the magnets 610 , 612 , 614 , and 616 in the bending zones 644 , 646 , 648 , and 650 , respectively.
Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.
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Methods for controlled electrospinning of polymer fibers are described. The methods include spinning a polymer fiber from a fluid comprising a polymer in the presence of an electric field established between a plurality of collectors and a jet supply device controlling the dispersion characteristics of the fluid by applying a magnetic field created by at least one magnet located after the point of jet formation. Different voltages are applied to at least two collectors of the plurality of collectors. At least one magnet, located between the jet supply device and at least one collector, creates a magnetic field substantially transverse or substantially collinear to an electrospinning jet stream. The magnetic field changes direction of travel of the electrospinning jet stream.
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This application is a divisional application of prior application Ser. No. 10/933,610 filed Sep. 2, 2004, now U.S. Pat. No. 7,424,932, the entire content of which are hereby incorporated by reference.
FIELD OF INVENTION
The present invention relates to hoisting devices. Particularly it pertains to a new lifting device used in conjunction with a ladder, and a method for raising construction materials onto the roof of a building.
BACKGROUND OF INVENTION
Construction workers are often called upon to transport construction materials and equipment onto the roof portion of a building. The materials may include roofing shingles, plywood sheets, bricks, ventilation units or even ornamental structures. Various lifting devices have been employed to accomplish this task. Such devices often require multiple persons to operate, have limited safety features and are often quite expensive to purchase and maintain.
Applicant proposes a load lifting system used in conjunction with a ladder, and a method to move a load to the roof of a building. The system is comprised of a carriage that rolls along the rails of conventional extension ladders and a self-contained hoisting mechanism for raising a load to the roof surface of a building.
The carriage of Applicant's lifting system includes a dual braking mechanism that reduces the risk of a loaded carriage sliding or rolling down the ladder during a lift or off of the roof once the load is brought to the roof surface. Applicant's lifting system also includes ladder rail adaptors to provide for a smooth transition of the carriage as it rolls along the rails of extension ladders and an eave adaptor to provide for a smooth roll surface between the ladder rails and the roof surface. The proposed lifting system also includes an infinitely adjustable ladder support to provide an intermediate support to the extension ladder.
SUMMARY OF INVENTION
The present invention provides a hoisting system for use in conjunction with a ladder, and a method to lift loads to a roof surface. The device is primarily intended to lift materials to the surface of pitched roofs typically used in residential construction. The device may also be employed to raise loads to flat or substantially flat roofs or to various levels of a wall during its construction and it may be of particular use in the construction of masonry walls.
The hoisting system is comprised of a load-bearing carriage having a roller axle and wheel assembly that allows the loaded carriage to roll up the rails of a ladder on its axels and then roll along a roof surface on the provided wheels to a desired unloading area. A rail guide is provided to maintain alignment of the carriage as it travels on the ladder rails.
A self-contained hoisting means is provided to roll the carriage along the ladder rails and along the roof surface. The hoisting means includes a roof anchor mechanism that adapts to the pitch of the roof in which it is used and thus allows for its employment on roofs having a variety of different roof slopes. The hoisting means is further comprised of a winch mechanism and pull cable arrangement having a support that works in cooperation with the roof anchor mechanism.
The carriage is further provided with a dual breaking mechanism as a safety device. The first breaking mechanism is comprised of a breaking bar that slides over the ladder rungs during a lift up the ladder but provides a positive stop against a ladder rung in the event of an untoward reversal of the carriage during the lift. The second breaking mechanism is comprised of elongated spikes that dig into the roofing surface and serve to hold the carriage on the roof in the event of an untoward reversal of the carriage while it is on a roofing surface.
Adaptors are provided for the ladder rails to allow for a smooth transition of the carriage between ladder rail extensions and from the ladder rails to the roof surface.
An infinitely adjustable ladder support is provided to give support to the extension ladder a point between its ends. This allows the user of the device to reduce the angle of the lift and as a consequence increase the lift capacity of the hoisting device.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of the ladder hoisting assembly.
FIG. 2 is a perspective top view of the ladder hoist carriage.
FIG. 3 is a perspective bottom view of the ladder hoist carriage.
FIG. 4 is an end view of the ladder hoist carriage on a ladder.
FIG. 5 is a side perspective view of the winch assembly.
FIG. 6 is a perspective view of the roof anchor.
FIG. 7 is a perspective view of the roof eave guide bar.
FIG. 8 is a perspective view of the ladder extension rail transition assembly.
FIG. 9 is a cross sectional view of the hoisting apparatus.
FIG. 10 is a perspective view of the ladder hoisting assembly ready for a hoist.
FIG. 11 is a perspective view of a load carriage.
FIG. 12 is a cross sectional view of the hoisting apparatus during a hoist.
FIG. 13 is a side view of the hoisting assembly on a roof surface.
FIG. 14 is a perspective view of the ladder support.
FIG. 15 is a cross sectional view of the ladder support adjustment clamp.
DRAWINGS
Reference Numerals
10
Lifting Hoist System
12
Carriage
14
Hoisting Assembly
16
Winch Assembly
18
Roof Anchor
20
Winch Cable
22
Ladder
23
Ladder Rail
23A
Ladder Extension Rail
24
Ladder Rungs
25
Ladder Support
26
Carriage Frame
27
Carriage Deck Assembly
27A
First Deck Portion
27B
Second Deck Portion
28
Carriage Deck Hinge
29
Deck Load Support
Bar
29A
Load Support Bar
30
Carriage Axle
Adjustment
Screw
30A
Axle Bearing
32
Carriage Axle
32A
Axle Bearing
34
Carriage Wheel
36
Carriage load stop
38
Lower Load Stop
Frame
40
Lower Load Stop Frame
42
Upper Load Stop
Columns
Frame
44
Upper Load Stop Columns
46
Load Stop Brace
46A
Load Stop Brace Support
48
Load Stop Adjustment Screw
50
Carriage Brake Assembly
52
Ladder Rung Brake Bar
54
Carriage Ladder Brake bearing
56
Carriage Ladder Brake Rung Stop
58
Carriage Roof Brake Assembly
60
Carriage Roof Brake Claw
62
Carriage Roof Brake Bearing
64
Carriage Ladder Brake Support Pins
66
Carriage Brake Engagement Lever
68
Brake Engagement Lever Bearing
69
Brake/Carriage Deck Latch
70
Carriage Hitch Bar
71
Carriage Hitch Ring
72
Rail Guide Assembly
74
Rail Guide
75
Rail Guide Adjustment plate
76
Rail Guide Adjustment Slot
78
Rail Guide Adjustment Screw
80
Winch
81
Winch spool
82
Winch Support Frame
83
Cable Guide
84
Winch Support Roof Anchor Stops
85
Winch Support Carriage Hitch
86
Roof Anchor Bar
86A
Roof Anchor legs
86B
Roof Anchor legs
87
Roof Anchor Winch Supports
88
Roof Anchor Cable Hitch
89A
Roof Anchor Pad
89B
Roof Anchor Pad
90
Roof Anchor Pad Bearing
91
Roof Anchor Spike Guide
92
Ladder Roof Eave Guide Bar
93
Eave Guide Bar Attachment Tab
95
Eave Guide Bar Bolt
96
Ladder Extension Rail Transition Assembly
97
Ladder Transition Rail
98
Ladder Transition Rail Support Plate
98A
Transition Rail Filler Plate
99
Ladder Transition Support Plate Bolt
101
Ladder Support Base
102
Ladder Base Legs
103
Ladder Support Pole
103A
Lower Support Pole Segment
103B
Upper Telescoping Support Pole Segment
104
Ladder Support Adjustment Clamp
104A
Ladder Support Adjustment Clamp
104B
Ladder Support Spring
104C
Ladder Support Spring Stop
105
Ladder Rung Support Bar
106
Ladder Rung Cradle
200
Building
210
Roof
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings and more particularly FIG. 1 , there is shown a prospective view of the hoisting system 10 of applicant's invention. The hoisting system 10 is typically used to lift materials from the ground or from a truck bed onto the roof of a building 200 . The system 10 is comprised of a hoisting assembly 14 used to hoist loads up a ladder 22 that extends to the roof 210 of the building 200 . The ladder 22 is shown as an extension ladder having lower ladder rails 23 and upper ladder extension rails 23 A, though single section, non-extending, ladders may also be utilized. As may be required, the extension ladder 22 may be supported as desired by a telescoping ladder support 25 .
The hoisting assembly 14 is comprised of a carriage 12 that rolls along and is supported by the rails 23 and 23 A of the ladder assembly. A winch assembly 16 having a winch cable 20 is used, in conjunction with a roof anchor 18 attached to the ridge of the roof 210 , to roll the carriage 12 along the ladder 22 to the roof 210 .
FIG. 2 , a top prospective view of the carriage 12 , and FIG. 3 , a bottom prospective view of the carriage 12 show the components of the carriage 12 . The carriage 12 is comprised of a frame 26 having carriage axles 30 and 32 supported on axle bearings 30 A, 32 A for rollably supporting the carriage 12 on the rails 23 and 23 A of the extension ladder 22 . Each carriage axle 30 , 32 has carriage wheels 34 that allow the carriage 12 to be rolled along the roof surface 210 when the carriage transitions from the rails 23 , 23 A of the ladder 22 to the roof surface 210 .
A carriage deck assembly 27 is supported on the frame 26 . The carriage deck assembly 27 has a first deck portion 27 A a second deck portion 27 B. These deck portions 27 A and 27 B are pivotally attached to the carriage frame 26 by means of carriage deck hinges 28 . To minimize load shifting during a lift the carriage 12 is provided with a deck load support bar 29 adjustably mounted to the frame 26 by means of a load support bar adjustment screw 29 A.
The carriage 12 has a carriage load stop 36 which is comprised of a lower load stop frame 38 having tubular lower load stop frame columns 40 and an upper load stop frame 42 having upper load stop columns 44 that slidably fit into the tubular support columns 40 and held in place by means of adjustment screw 48 . This arrangement allows for telescopic adjustment of the height of the load stop 36 . The load stop 36 has a load stop brace 46 mounted on load stop brace support 46 A attached to the upper load stop frame 42 . The upper load stop frame 42 may be reversed to position the load support brace 46 atop a load carried on the deck surface 27 .
The carriage 12 is provided with a carriage hitch bar 70 mounted to the frame 26 of the carriage 12 . The carriage hitch bar 70 has a carriage hitch ring 71 for attachment of the cable 20 from the winch assembly 16 .
Referring to FIG. 3 , the carriage brake assembly 50 is shown below the deck 27 of the carriage 12 . The carriage brake assembly 50 is comprised of a ladder rung brake bars 52 having an upwardly canted configuration that pivots about the axle 30 by means of a ladder brake bearing 54 . This pivotal mounting allows the brake bar 52 to slide over ladder rungs 23 , 23 A as the carriage 12 is pulled up the ladder 22 . The ladder brake bars 52 support a ladder brake rung stop 56 at their ends. The rung stop 56 will slide over the ladder rungs 23 and 23 A during a lift but will fall down to engage a ladder rung 24 in the event the carriage 12 rolls down the ladder 22 during the hoisting of a load.
The carriage brake assembly 50 also includes a roof brake assembly 58 . The roof brake assembly 58 is comprised of a roof brake claw 60 that is pivotally mounted on the axle 30 between the ladder rung brake bars 52 by means of roof brake bearings 62 . Upper and lower carriage ladder support pins 64 attached to the claw 60 impede the full rotation of the roof brake claw 60 on the axle 30 . The pins 64 engage the brake bars 52 and allow the carriage brake claw 60 to dig into a roof surface when the carriage 12 rolls down a roof surface.
The carriage brake assembly 50 and roof brake assembly 58 are engaged and disengaged by means of a brake engagement lever 66 that pivots on a brake engagement lever bearing 68 mounted on the roof brake claw assembly 58 . When the brake assembly is disengaged the lever 66 is upwardly biased against the carriage hitch bar 70 . To engage the braking system prior to making a lift, the engagement lever 66 is pivoted off of the hitch bar 70 to allow the claw 60 of the roof brake assembly 58 and the brake bars 52 of the carriage brake assembly 50 to freely pivot on the axle 30 .
The carriage brake assembly 50 and roof brake assembly 58 can also be completely disengaged, as shown in FIG. 9 , to avoid its contact with the ladder rungs 23 , 23 A and roof 210 to allow the carriage 12 to roll down the roof and the ladder. This is accomplished by means of a brake deck latch 69 positioned below the carriage deck 27 B. Raising the carriage bar 52 for engagement in the deck latch 69 allows the carriage 12 to be rolled down the ladder and/or roof and also identifies to a user that the brake assemblies 50 and 58 are disengaged.
In FIG. 4 , an end view of the carriage 12 , rail guide assemblies 72 are shown mounted to the carriage frame 26 to steer the carriage 12 as it rolls along the rails 23 , 23 A of the ladder 22 . Each rail guide assembly 72 is comprised of a rail guide bar 74 positioned along the outside edges of the ladder rail 23 . The position of the rail guide bar 74 with respect to the ladder rail 23 may be adjusted by means of the rail guide adjustment plate 75 having an adjustment slot 76 and rail guide adjustment screw 78 . The adjustment of the rail guide assembly 72 allows for the carriage 12 to be adapted to fit the various widths of a selected ladder 22 .
The winch assembly 16 of the hoist assembly 14 is shown in FIG. 5 . The winch assembly 16 is comprised of a winch 80 having a winch spool 81 and winch cable 20 . The winch 80 may be electrically powered though other sources of power may also be employed. The winch 80 may be remotely controlled by mechanical or electronic means. The winch 80 is mounted on a winch support frame 82 having a cable guide 83 . The winch support frame 82 has winch support roofing anchor stops 84 for supporting and securing the winch assembly 16 on the roof anchor 18 . The anchor stops 84 are spaced apart so as to allow them to also be supported on the ladder rails 24 if lifting the carriage to the roof surface is not desired. Winch support frame 82 also has a carriage hitch 85 for attaching the winch assembly 16 on the carriage frame 26 .
The roof anchor assembly 18 is shown in FIG. 6 . The roof anchor assembly is comprised of a roof anchor bar 86 having vertically oriented roof anchor legs 86 A and 86 B positioned along the axis of the anchor bar 86 . Transversely positioned anchor bars 87 are positioned on the anchor bar 86 for corresponding engagement with winch anchor stops 84 . Roof anchor legs 86 A, 86 B have corresponding support pads 89 A, 89 B that have perforations serving as nail, spoke or screw guides 91 . The spike guide 91 allows the anchor pads 89 A, 89 B to be secured to the roof surface 210 by nails or other means. The roof anchor leg 86 B is somewhat longer than roof leg 86 A to allow it to engage the roof surface on the opposite side of the roof ridgeline. The roof anchor leg 86 B is pivotally attached by means of roof anchor leg bearing 90 to the roof support pad 89 B to facilitate its alignment with the roof surface. While the roof anchor 18 may be utilized without the use of nailing the pads to the roof surface, such nailing allows a further measure of safety for the user.
FIG. 7 shows an adaptor piece for a typical extension ladder 22 to more readily allow the carriage 22 to be moved from the ladder 22 onto the roof 210 . This is accomplished by means of attaching an eave guide bar 92 to the ends of the ladder rails 23 or 23 A, as may be the case. Each eave guide bar 92 is pivotally attached to the ladder rails 23 A, as shown in FIG. 7 , by means of an attachment tab 93 and a guide bar bolt 94 . The pivotal attachment of the guide bar 92 allows for adjustment to roofs of various pitches or inclines.
FIG. 8 shows a rail transition assembly 96 for use in adapting a typical extension ladder to facilitate travel of the carriage 12 along the ladder rails 23 to ladder rails 23 A. When the rails of the typical extension ladder are extended, there is a difference in rail height and in rail spacing width from one section of the ladder to the other. The ladder rail transition assembly 96 adapts the ladder rails to allow for a smooth transition in rail height and rail spacing width from one rail section to another. The rail transition assembly 96 is comprised of a ladder transition rail 97 secured to ladder extension rail 23 A. The ladder transition rail rests on the top of ladder rail 23 as shown in FIG. 8 . Transition rail 97 is pivotally attached to the transition rail 23 A by means of transition support plate bolt 99 and transition rail filler plate 98 A if required. The transition rail assembly 96 is thus adaptable to ladders of varying dimensions.
Referring again to FIG. 1 , the hoisting assembly 10 is shown being prepared for an initial lift to the roof surface. To make such a lift, a user would climb the ladder 22 to the roof surface 210 and secure the anchor assembly 18 at the ridge of the roof. The cable 20 is then extended from the winch assembly 16 , mounted on the carriage 12 by means of the winch carriage hitch 85 , to the roof anchor assembly 18 and attached to the cable hitch 88 . Engagement of the winch 80 of the winch assembly 16 will pull the carriage 12 by means of the cable 20 on the axle rollers 30 , 32 along the ladder rails 23 , 23 A to the surface of the roof 210 . When the carriage 12 reaches the roofs surface, the carriage 12 will roll along the roof 210 by means of the wheels 34 . At this stage, the carriage 12 is held in place on the roof surface by means of wheel chocks or an intermediate support cable (not shown) temporarily placed between the carriage 12 and the anchor assembly 18 . This allows for the winch assembly 16 to be removed from the carriage 12 and mounted on to the anchor assembly 18 by means of the winch supports 87 and winch anchor stops 84 . The cable 20 is extended from the roof anchor 18 and winch assembly 16 and attached to the carriage hitch ring 71 of the carriage hitch bar 70 .
To lower the carriage 12 from the roof surface to 210 and down the extension ladder 22 , the break assemblies 50 and 58 are disengaged by means of lifting the deck 27 B to expose the brake/carriage deck latch 69 and then lifting the ladder rung brake bar 52 and placing the brake rung stop 56 on the deck latch 69 . This procedure will disengage the break assemblies 50 and 58 , by holding the bars 52 and the claw 60 above the roof surface 210 and the ladder rungs 24 , so that the unloaded carriage 12 may be rolled along the roof 210 and ladder 22 . FIG. 9 shows a cross sectional view of the carriage brake assembly 50 disengaged by means of the brake/carriage brake latch 69 as described.
FIG. 10 shows the hoisting assembly 14 just prior to loading the deck 27 and hoisting the carriage 12 and the accompanying load. At this step in the process, the winch assembly 16 is mounted on the roof anchor assembly 18 , the cable 20 is connected to the carriage hitch ring 71 of the carriage 12 , and the carriage brake assembly 50 and the roof brake assembly 58 have been engaged by rotating and moving the lever 66 from its fixed position against the ladder hitch bar 70 .
FIG. 11 shows a loaded carriage 12 made ready for a lift. As shown the carriage 12 is loaded with boxes 250 representing roof materials, shingles or the like. These boxes 250 are supported on the carriage bed 27 and are prevented from shifting by means of the adjustable deck load support bars 29 . The Boxes 250 stacked on the carriage deck 27 are further supported by the load stop brace 46 . Load stop brace adjusts for the height of the boxes 250 as the upper load stop frame 42 has columns 44 which slide into the lower load stop columns 40 of the lower load stop frame 38 and the orientation can be reversed to allow the load support brace 46 to rest on top of the boxes 250 . The upper load stop frame 42 can then be held in place by means of adjustment screws 48 .
FIG. 12 shows a cross sectional view of a loaded carriage 12 in place on the ladder 22 . As it can be seen, the carriage 12 is supported on axles 30 and 32 as it rolls along the rails 23 and 23 A of the ladder 22 . The ladder break assembly 50 is shown in its engaged position impede the backward movement of the carriage 12 on the ladder 22 but allow its forward movement up the ladder 22 . Engagement of the winch 80 will pull the carriage 12 upward on the ladder 22 by means of the cable 20 . As the carriage 12 moves forward and upward on the ladder 22 , the pivoting claw 60 and the ladder rung brake bar 52 of the brake assemblies 50 and 58 glide over the ladder rungs 24 . Any downward movement of the carriage 12 on the ladder 22 would provide for engagement of the rung stop 56 of the ladder rung brake bar 52 with a rung 24 to prevent further downward movement of the carriage 12 .
FIG. 12 also shows the adjustable ladder support 25 in place to provide additional support to the ladder 22 as may be thought necessary on lifts made on longer ladder spans. The ladder support pole 103 has a lower support pole segment 103 A and an upper telescopic support pole segment 103 B that may be adjusted by means of support adjustment clamp 104 to place ladder rung cradle 106 in a desired position against a desired ladder rung 24 .
FIG. 13 shows the carriage 12 on a roof surface 210 . At this stage the carriage 12 has transitioned from the ladder 22 to the roof surface 210 by means of the ladder roof guide bar 92 . The wheels 34 allow the carriage 12 to be rolled along the roof surface by means of the cable 20 and winch assembly 16 . Should the cart 12 roll downward on the roof surface due to a defect of the winch 80 or other reason, the roof brake claw 60 of the roof brake assembly 58 will engage and dig into the roof surface 210 . Because the roof brake claw 60 pivots on roof brake bearing 62 , the roof brake claw 60 is adaptable to different types of roof surfaces and roof pitches. The carriage ladder brake support pins 64 engage and hold the pivoting brake claw 60 in place to prevent over pivoting and rotation of the claw 60 .
FIG. 14 shows the telescopically adjustable ladder support 25 . The ladder support 25 has a base 101 on which is vertically mounted a telescoping support pole 103 . The telescoping support pole 103 is comprised of a lower pole 103 A and an extendable upper support pole 103 B that is telescopically adjustable in length by means of pole adjustment mechanism 104 . The support pole 103 B includes a rung support bar 105 to which is mounted lateral rung cradles 106 . In use, the ladder support 25 is placed at a desired position under the ladder 22 and the pole 103 B is extended as desired to place the rung cradle 106 under the desired ladder rung 24 to support the ladder 22 as may be desired.
FIG. 15 shows a cross sectional detail of the ladder rung adjustment assembly 104 . The ladder support adjustment assembly 104 is comprised of a ladder support adjustment clamp 104 A and ladder support 104 B that places the adjustment clap 104 A in bias contact with support spring stop 104 C. This allows for an infinite adjustment of the extension of ladder support pole 103 B.
As can be seen from the illustrations, the carriage 12 , in combination with the ladder 22 , the roof ridge anchor 18 , and the hoist assembly 16 , provides for a self-contained hoisting assembly 14 . This hoisting assembly 14 allows the winch 60 to be transported to the roof 210 on the carriage 12 , detached from the carriage 12 , and mounted on the roof anchor 18 . The cable 20 may then be attached to the hitch ring 71 of the carriage 12 to allow the carriage 12 to be lowered down the roof and ladder 22 . The user never has to manually bring the winch 60 to the roof surface 210 to facilitate a hoisting of a load. Once the carriage 12 is off the roof 210 and on the ground or a truck bed, the deck 27 may be loaded and pulled up the ladder 22 by means of the winch assembly 16 . The process may be is repeated as necessary.
The carriage 12 may also be moved on the ladder 22 in the matter described above by placing the anchor stops 84 of the winch support frame 80 on the rungs 24 of the ladder and attaching the cable 20 to the carriage winch ring 71 . This will allow loads to move up a ladder positioned against a wall without the use of the anchor assembly 18 .
The foregoing is considered illustrative only of the principles of the invention. It may be apparent to those skilled in the art that numerous modifications and changes may be made in such details without departing from the spirit and principles of the invention.
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A hoisting device and method for hoisting material up an extension ladder. The device includes a load-carrying carriage having a wheel and roller axle assembly that also serves as rollers for engagement with the rails of the ladder. The wheel and roller axle assembly allows the cart to transition from the ladder rails to the roof surface. Also provided is a dual braking means that serves to prevent the carriage from rolling back down the ladder or off of the roof in cases of cable malfunction. The method employs a hoisting mechanism having a removable winch used in conjunction with a releasable coupled pull cable that is brought to the roof surface on the carriage, detached from the carriage, mounted on the roof and used to return the carriage to and from the roof during hoisting operations. An adjustable ladder support is provided to support the ladder during a hoist.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of U.S. patent application Ser. No. 15/501,992, filed Feb. 6, 2017, which is a Section 371 U.S. National Stage Filing of International Application No. PCT/EP2015/069130, filed Aug. 20, 2015, which was published in the English language on Mar. 10, 2016, under International Publication No. WO 2016/034423 A1, which claims priority to German Patent Application No. 20 2014 007 174.8, filed on Sep. 2, 2014, the disclosures of which are incorporated herein by reference.
[0002] The present invention relates to devices for preventing fatal bathroom accidents. Particularly, the present invention relates to devices for preventing fatal bathroom accidents relating to falls and/or drowning.
BACKGROUND OF THE INVENTION
[0003] The present generation of elderly people remains more active than ever. Rather than moving into specially observed homes and retirement homes, they regard their own homes, having lived there for a long time, the ideal place to live after retirement and arrange themselves accordingly; this is a generational change that has happened only within the last 15 to 25 years. Before then, retirees usually considered moving to a retirement home or a living facility at a much earlier age than nowadays. Presently, retirement homes are used more to help those with pressing diseases such as dementia or other ailments requiring around-the-clock care.
[0004] Most accidents happen at home. Especially accidents in bathrooms bear a high risk of fatal injuries due to slippery surfaces and a lack of protecting clothes. For example, elderly people may faint while taking a bath. If the fainted person is not able to wake up in time, it may drown in the bath tub. Another common accident is slipping in the shower which may lead to bone fractures or similar injuries.
[0005] Accordingly, there is a need for safety methods and equipment to prevent fatal injuries in the bathroom, especially for elderly people or other susceptible persons (e.g. persons suffering from epilepsy).
[0006] Amongst the ageing and those with multiple sclerosis or epilepsy, drowning in a bathtub is a common cause of death. Once a person faints in the bath tub, the body slides down until the head is under the water surface; if he or she does not recover consciousness, drowning occurs in less than 3 minutes.
[0007] The present invention uses the movement of the fainting body to increase the chances of survival by making the water flow out of the tub.
[0008] Furthermore, slipping in showers is a known, but little researched cause of severe injuries and death amongst the elderly. The leading injuries sustained in a fall in the shower are:
broken upper leg bones broken hips broken lower leg bones, in particular the shin concussions spinal injuries broken noses, fingers and hands, and fractured skull.
[0016] While some injuries heal, others have serious complications. For example, a broken hip of an already weak person can entail such demanding surgery that the operation might result in death.
[0017] The present invention is not trying to hinder the fall. Though attempts have been made, primarily within the American medical community, fall prevention efforts have been unsuccessful. A fall can have several causes-all of which cannot be helped by adding more handles to the shower or installing anti-skid mats. Particularly senior citizens may suddenly feel a loss in the leg muscles (“weak knees”), experience dizziness, and slip while showering; here neither the anti-skid mat nor the handles help, as the center of gravity is constantly changing when one showers.
[0018] The most perfect protection would either include a chair in the shower or wearing a belt, structured like in a parachute. However, the latter is not only uncomfortable, but difficult to put on; the areas where the belt is strapped to make it impossible to clean the underlying skin. Though the shower chair is commonly used by people unable to stand, it still remains an uncomfortable alternative. Slipping still occurs when exiting the shower, once the chair starts to move around, or when the body is covered with soap and water.
BRIEF SUMMARY OF THE INVENTION
[0019] Accordingly, the present invention is provided as claimed in the appended independent claims. Accordingly, in a first preferred embodiment, the present invention provides a bath plug device for closing a drain pipe of a bath tub, comprising a bath plug, a cone attached to the top of the bath plug, and at least one pedal-like unit attached to the left and/or to the right of the cone.
[0020] In a second preferred embodiment, the present invention provides a bath plug device for closing a drain pipe of a bath tub, comprising a bath plug, a protrusion attached to the top of the bath plug, and at least one foot rest unit attached to the left and/or to the right of the protrusion.
[0021] In one embodiment according to the second preferred embodiment, the at least one foot rest unit (or pedal-like unit) covers substantially the whole width of the bath tub.
[0022] In one embodiment according to the first or the second preferred embodiment as described above, the bath plug device has an overall density which is slightly below the density of water such that the bath plug device starts to float as soon it is detached from the drain pipe.
[0023] In one embodiment according to the first or the second preferred embodiment as described above, the bath plug is connected via a fixed wire to either an electric motor or a compressed air tube.
[0024] In one embodiment according to the first or the second preferred embodiment as described above, a tilt sensor is fixed inside the protrusion, which in turn is wirelessly connected to a bath security switch and/or a house server.
[0025] In a third preferred embodiment, the present invention provides a shower fall prevention device, comprising a fixing point on a ceiling of a shower and two arm pit hooks pivotable connected to the fixing point.
[0026] In one embodiment according to the third preferred embodiment as described above the shower fall prevention device further comprises a rod connected between the fixing point and a bar, wherein said arm pit hooks are connected on right and left ends of the bar.
[0027] In one embodiment according to the third preferred embodiment as described above the shower fall prevention device further comprises a strong rubber band or an extendable and retractable belt rolled up in a box, fixed to the fixing point and connected between the fixing point and the rod.
[0028] In one embodiment according to the third preferred embodiment as described above the shower fall prevention device further comprises a handle next to the rod and connected to the bar via an extension of a free end of one of the arm pit hooks.
[0029] In one embodiment according to the third preferred embodiment as described above the shower fall prevention device further comprises a cushion formed on an extension of a free end of one of the arm pit hooks, wherein said cushion is movable upwards and to the side.
[0030] In a fourth preferred embodiment, the present invention provides a shower fall prevention device, comprising a strong rubber band or an extendable and retractable belt rolled up in a box, fixed to the ceiling near the center of the shower ceiling, a rod fixed to the strong rubber band or the extendable and retractable belt, an solid part (e.g. an iron part) fixed to the rod at or near the middle of a straight or slightly curved part of the solid part, a handle positioned left of the rod and connected to the solid part, wherein the solid part is bent down from the handle, then backwards in a half circle, then up again, from there to the straight or slightly curved part to the right side, where it bends down again in a half circle, and a cushion formed on an extension on the right side of the straight or slightly curved part, wherein said cushion is movable upwards and to the side.
[0031] In a fifth preferred embodiment, the present invention provides a shower fall prevention device, comprising at least one rod fixed to a fixing point, an solid part fixed to the at least one rod on a straight or slightly curved part of the solid part, a handle connected to the solid part, wherein the solid part is bent down from the handle, then backwards in a half circle, then up again, from there to the straight or slightly curved part to the right side, where it bends down again in a half circle, and a cushion formed on an extension on the right side of the straight or slightly curved part, wherein said cushion is movable upwards and to the side.
[0032] In one embodiment according to the third to fifth preferred embodiment as described above the straight or slightly curved part of the solid part (or the bar) is extendable and retractable by a telescopic mechanism in the solid part.
[0033] In one embodiment according to the third to fifth preferred embodiment as described above the rod and the solid part have a full cushion placed around the whole area.
[0034] In a sixth embodiment, a shower fall prevention system is provided, comprising a shower fall prevention device according to one the third to fifth embodiment as described above, a switch having wireless connectivity and a battery, attached to the belt or the retraction unit, and a computing device wirelessly connected to the switch and sending alarm information if the switch is activated.
[0035] In the sixth embodiment, the shower fall prevention system further comprises a switch having wireless connectivity to the computing device and a battery integrated to the cushion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] All figures presented herein are of a schematic nature and parts should be interpreted in relation to another only. The drawings and the description use reference signs to facilitate the understanding of the present invention. Wherever appropriate, same reference signs are used to label same or similar parts of the invention.
[0037] FIG. 1 is a schematic diagram of a bath plug device according to a preferred embodiment of the present invention.
[0038] FIG. 2 is a schematic diagram of a shower fall prevention device according to a first preferred embodiment of the present invention.
[0039] FIG. 3 is a perspective view diagram of a shower fall prevention device according to the first preferred embodiment of the present invention.
[0040] FIG. 4 is a schematic diagram of a shower fall prevention device according to a second preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
1: Device Against Drowning in Bathroom Tubs—Manual Version
[0041] FIG. 1 is a schematic diagram of a bath plug device according to a preferred embodiment of the present invention. According to FIG. 1 , a cone 20 is used attached to the top of the bath plug 10 , at least one pedal-like unit 30 (preferably two units as shown in FIG. 1 ) to the left and/or to the right of the cone 20 are attached, covering more or less the whole span of the bath tub. The user is supposed to have his feet not on the side of the cone, but closer to his own body, preferably by lifting his knees slightly.
[0042] Once the user becomes unconscious, the body moves down along the bath tub, the feet pushing against the pedals 30 or the cone 20 itself This moves the cone 20 away from the user and lifts the bath plug 10 , allowing the water to flow out. In one embodiment, the bath plug device has an overall density which is slightly below the density of water (e.g. by choice of material of the bath plug formed cavities in the plug that contain air) such that the bath plug device starts to float as soon it is detached from the pipe. Thus, the bath plug 10 will not return to a pipe closing state once it is detached such that drain off of the bath tub water is not disturbed.
[0043] With the lowering of the water level, the chance of survival increases dramatically. It is then only a matter of the speed of the water flowing out and the time needed for the bath tub to drain. This can be calculated by the diameter of the pipe and the water level.
2: Bathroom Tub Drowning—Electric Version
[0044] In an electric version (not shown), the cone 20 is placed on top of the draining pipe. However, the bath plug 10 resides in the cone 20 , the plug being connected with a fixed wire to either an electric motor or a compressed air tube and a tilt sensor, e.g. a girometer fixed inside the cone 20 , which in turn are wirelessly connected to a bath security switch and/or a house server providing safety services like software that may trigger an alert at official services (a call center, police, ambulance, fire department etc.). On the side of the cone 20 , between the plug 10 and the motor or tube, the cone 20 has an opening. In the fully retracted mode, the plug is above the opening.
[0045] Once the bathroom switch is pressed, this information is transmitted to the cone 20 , causing the electric motor or compressed air tube to lift the plug over the opening. This causes water to enter the cone 20 and flow through the now-open drain pipe, thus lowering the water level.
[0046] The pedals 30 described earlier can potentially be attached to the electric embodiment of the cone 20 as well.
[0047] If the cone 20 is pressed down, the embedded girometer can trigger the upward movement of the motor or tube, and send a distress signal to the bathroom security switch and/or the house server such that further safety services are informed. E.g. a call center operator may first be allowed to communicate to the user in the bathroom and, if the user does not react, pictures or even a video signals may be transmitted to the operator. However, other safety means, like informing neighbors, residents of the home, or nearby relatives (“first responders”), may be triggered in addition or as an alternative. Such information may be provided via software on mobile phones of the respective first responders. Such measures (i.e. who should be informed in what case) may be selected by the user beforehand.
3: Shower Fall Prevention
[0048] FIG. 2 is a schematic diagram of a shower fall prevention device according to a first preferred embodiment of the present invention. FIG. 3 is a perspective view diagram of a shower fall prevention device according to the first preferred embodiment of the present invention. The present invention has been made to give ease of movement. Normally, the structure does not require contact with the skin.
Hardware
[0049] A rod 100 , preferably made from iron or stainless steel, described is fixed to the ceiling near the center of the shower ceiling either by a strong rubber band (not shown) with very little leeway or preferably—for user comfort—by an extendable and retractable belt 110 is rolled up in a box 112 similar to a safety belt retraction unit. If the unit is attached to a bath room, it will be placed on the ceiling, vertically aligned to where the person usually stands while showering.
[0050] To the left side of the rod 100 , a handle 200 is attached. An solid part 300 is bent down from the handle 200 , then backwards in a half circle, then up again, from there in a straight or slightly curved line (indicated in FIG. 3 ) to the right side, where it bends down again in a half circle. The solid part 300 is fixed to the rod 100 at or near the middle of the straight or slightly curved part.
[0051] Said straight or slightly curved part is extendable and retractable, e.g. by a telescopic mechanism in the rod, as an example but not limited to a expansion plug telescopic rod or other suitable detent mechanisms. The solid part 300 is bent up again, then to the left to about one half of the full width of the unit. At that point a small, soft cushion 400 is placed; in a preferred version of the unit, this cushion 400 can be moved upwards and to the side and may be locked in a position by a suitable locking mechanism. The cushion 400 is provided to prevent injuries of face and head of a user slipping in the shower and falling forward towards the shower wall (not shown).
[0052] For more comfort the rod 300 can have a full cushion (not shown) placed around the whole area, in particular where the armpits would fall. In an alternative version, shower walls can be covered with a delta-shaped cushion (not shown), in which the long side of the triangle is attached to the wall, the shortest side under the longer side of the cushion triangle.
[0053] FIG. 4 is a schematic diagram of a shower fall prevention device according to a second preferred embodiment of the present invention. Basically, the embodiment of FIG. 4 corresponds to the embodiment shown in FIGS. 2 and 3 . The difference between said embodiments is the manner in which the rod 100 ′ of FIG. 4 is fixed. Rod 101 ′ does not have a fixing to a flexible member like in FIGS. 2 and 3 (belt 112 ) but instead comprises one or more solid rods 100 ′ fixed to fixing points somewhere in the shower. E.g. rod 100 ′ may be fixed directly to a shower tub or to walls surrounding the shower. Number and stability of rods 100 ′ are chosen such that the device provides enough stability to support a falling person. Care should be taken to not place the rods 100 ′ such that the user is hindered at entering and leaving the shower.
Method of Use
[0054] The user enters the shower and moves his body through the opening in front of the fall prevention unit, so that the straight or slightly bent part is close to his back, running from shoulder to shoulder. He puts his left arm through the left part, his left armpit over the unit's left half circle; his left hand grabs the handle 200 on his left side. He then stretches his right arm over the right half circle. He moves the unit on the back below his shoulders and extends or retracts the unit to a comfortable width, then places the soft cushion 400 in front and near his head.
[0055] Once the user has put on the solid part of the mechanism, he or she may move freely inside the shower, only obeying that the left and right curves stay below the shoulders.
Functionality
[0056] In the case of a fall, the body of the user moves downward and/or forward. The forward movement is stopped on the left side by the solid piece with the handle 200 and in the middle by the cushion 400 near the face; this cushion stabilizes the head in the case in the case of a severe fall. The person slides down, having the fall stopped when the armpit falls in the downward half circles.
[0057] Then, the fall is stopped either by the rubber band (not shown) or by the lock of within the belt retraction unit 112 .
[0058] The cushion on the wall (described above; not shown) would in severe cases cushion the back of the head against the wall; by placing the second-longest side on top, the head can slide down over the cushion, not having to move over a top or bottom step, which might cause additional head injuries.
Connection to a Home Security Unit
[0059] In a preferred version of the invention, a switch with a wireless connection and battery is attached to the belt 110 or the retraction unit 112 . Once the impact is transmitted to the rubber band or the retraction unit locks, the switch sends a signal to either the remote server directly or to the bathroom switch unit, which uses this signal as if the alarm has been triggered.
[0060] The switch can also be integrated into the cushion 400 so that a strong push against the cushion triggers the alarm.
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The present invention relates to devices for preventing fatal bathroom accidents relating to drowning. Accordingly, in a first preferred embodiment, the present invention provides a bath plug device for closing a drain pipe of a bath tub, comprising a bath plug, a cone attached to the top of the bath plug, and at least one pedal-like unit attached to the left and/or to the right of the cone.
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CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of U.S. Ser. No. 595,550 which was filed on Oct. 11, 1990, now U.S. Pat. No. 5,040,620.
FIELD OF THE INVENTION
The present invention relates to an apparatus which can be attached to a drillstring to improve volumetric and drilling efficiencies, reduces time and energy costs of drilling, and increases drill bit life. The apparatus is a sleeve which can be attached to the outside of a drillpipe, which sleeve contains one or more helical pumping chambers for enhancing the movement of drilling mud and cuttings from bit/formation interface to borehole and thence to the surface. The full spectrum of boreholes from true vertical through "high angle" and including horizontal is encompassed. However, it is understood that the vertical portion of the borehole through unconsolidated formation and gumbo has been cased prior to running this apparatus.
BACKGROUND OF THE INVENTION
During the drilling of a borehole, or well, through a subterranean formation, drilling mud-a rheolitic slurry of fluid and buoyant suspension agent, e.g. bentonite-is pumped through a passageway in the drillstring to the bit, where it is injected at high velocity and pressure against the formation through jets located in the bit. The particular consistency of the drilling mud captures the cuttings generated by the bit, while its buoyant character assists the cuttings to rise out of the path of the bit. Because the diameter of the drill bit exceeds that of the other drillstring components, the cutting-laden drilling mud rises to the surface in the annulus defined by the drillstring and the wall of the borehole. Because the cutting-laden drilling mud can interfere with the drilling process, it is desirable to move it to the surface at a faster rate than conventional drilling presently allows.
Reduction in volumetric efficiency attributable to reduced effectiveness of the drilling mud hole-cleaning ability impacts a number of parameters. Because some of the cuttings are not removed from the path of the drill bit quickly enough, drilling efficiency (the rate of penetration or ROP) is reduced, leading to increased drilling time and energy requirements to achieve a specified borehole depth. Additionally, energy is lost by grinding the cuttings remaining in the path of the drill bit. The effect increases the difficulty of removing the cuttings and decreases the useful life of the bit--a substantial consideration in costly diamond drilling bit applications. Moreover, frequent removals of the drillstring to replace worn bits is a time consuming and expensive process, while concomitantly increasing the risk of a blow-out endangering personnel.
Yet another important problem encountered in drilling oil and gas wells is the phenomena of "differential sticking." Differential sticking occurs when the fluid in the drilling mud, located in the drillstring-borehole annulus, is absorbed unevenly around the periphery of the drillstring through the porous media of the borehole wall. This fluid loss induces a pressure differential across the drillstring diameter which causes the drillstring to be deflected against the borehole wall on the side experiencing the fluid loss, and can lead to halting engagement of the drillstring against the borehole wall. Once so engaged, the unbalanced fluid pressure acts to keep the drillstring in engagement with the borehole wall. The torque required to free the drillstring may exceed the capacity of the rotary table or the top drive used to drive the drillstring, or may exceed the yield strength of a drillstring component, leading to "twistoff" (torsion induced fracture). Differential sticking may result in the loss of the drill bit and a portion of the drillstring, thereby necessitating time consuming and extremely expensive procedures to recover the detached drillstring portion. In some cases, where the detached portion cannot be retrieved, the drill operator may have to abandon the borehole and begin anew.
A final phenomenon observed with conventional drillstrings is that of "key seating" at "doglegs" (borehole direction changes) and "kick-off-points", i.e., locations at which the angle of attack of the drill bit and drillstring is altered as the inclination from the vertical is increased. The phenomena of key-seating arises when there is sufficient bend in the borehole path to cause a portion of the drillstring to come into contact with one side of the borehole wall. This contact, if not substantial enough to cause differential sticking, can result in the drillstring forming a groove approximately the diameter of the drillstring in the borehole wall. If viewed in cross-section perpendicular to the borehole longitudinal axis, the borehole and groove would resemble a keyhole, with a large lower portion and a narrower upper portion. When key-seating occurs, it may no longer be possible to withdraw the drillstring from the borehole, since the larger diameter elements of the drillstring assembly (drill collars, stabilizers, etc.) will be unable to pass through the narrow groove. The phenomena of key-seating is due in large part to the rigidity of conventional drillstring components, which are unable to provide enough flexure to accommodate borehole directional changes and changes in the angle of attack. As with differential sticking, key-seating can lead to twistoff, necessitating time consuming retrieval procedures or abandonment of the borehole.
The aforementioned problems have provided a fertile ground for invention, and a number of prior art drillstring component designs are directed toward resolving one or more of these problems. One solution adopted by a number of prior art drillstring components, including the present invention, is the use of a helical flat or groove around the periphery of the drillstring component. Prior art drillstring components using such a solution may generally be grouped into two categories, each characterized by a disadvantage that the present invention is designed to overcome.
A first category of prior art helical groove drillstring component employs screw-like threads or broad V-shaped notches. Fitch U.S. Pat. No. 3,085,639 discloses a drill collar having screw-like threads on its periphery for drilling straight boreholes, wherein the flights of the screw coact with the borehole as a screw conveyor in removing cuttings from the vicinity of the drill bit. Arnold U.S. Pat. No. 3,194,331 and Massey U.S. Pat. No. 3,360,960 disclose, respectively, drillstring components having a single and multistep V-shaped helical groove on the circumference designed to reduce differential sticking, increase drilling mud flow through the borehole-drillingstring annulus, and to act as a broach to reduce key-seating.
In operation, the configuration of the helical groove in all three of these patents is such that the sharp edges of the grooves may strip the drilling mud lining the borehole wall (referred to as mud wallcake), leading to instability of the borehole wall and concomitant loss of fluid from the borehole. The drillstring component of the present invention is designed to leave intact the desired wallcake thickness, generally 3/32", while still providing superior performance by increasing drilling mud flow up the annulus, plus reducing differential sticking and key-seating.
A second category of helical groove drillstring component employs a spiral groove wherein the groove constitutes essentially a chord intersecting two points on the circumference of the drillstring component. Fox U.S. Pat. No. 2,999,552, Chance et al. U.S. Pat. No. 4,460,202, and Hill et al. U.S. Pat. No. 4,811,800 all disclose spiral groove drillstring components wherein he groove forms a chord on the component, when viewed in traverse section. The purpose of the groove is to reduce differential sticking, improve flow of drilling mud up the borehole-drillstring annulus and to increase the load on the drill bit in directional drilling applications. Hill et al. U.S. Pat. No. 4,811,800 discloses trading-off drillstring component service life in favor of increased drillstring flexibility by employing a relatively deep spiral chord-style groove. The drillstring component of the present invention is designed to provide the benefits attributed to these prior art chord-style spiral groove drillstring components, plus superior service life and flexibility in short radius directional drilling applications.
In view of the foregoing, it is an object of this invention to provide a drillstring component for drilling high angle and short radius directional and horizontal boreholes which experiences reduced mechanical fatique duty relative to previously known drillstring components, and which is readilly integrable with existing drilling systems, including downhole drilling mud-driven turbine style motors ("mudmotors").
It is a further object of this invention to provide a drillstring component for drilling high angle, directional and horizontal boreholes which improves volumetric and drilling efficiencies, reduces time and energy costs of drilling, and increases drill bit life relative to that achieved with previously known drillstring components.
It is another object of this invention to provide a drillstring component for a drilling high angle, directional and horizontal boreholes which substantially reduces the incidence of differential sticking, thereby reducing the major costs associated with retrieval of detached drillstring portions or abandonment of a partially drilled well.
It is yet another object of this invention to provide a drillstring component for drilling high angle and horizontal boreholes which has adequate flexibility to reduce the costs and additional effort required by incidents of key-seating and possible twistoff of the lower portion of the drillstring.
It is still another object of this invention to utilize the rotary motion of the drillstring to induce a turbine-style pumping ("turbo-pumping") action of the cutting-laden drilling mud away from the drill bit and subterranean formation interface toward the drilling mud treatment equipment at the borehole entrance.
This invention includes method steps carried out in sequence for obtaining the desired borehole-cleaning capability when drilling high angle, directional and horizontal boreholes.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a component for attachment to a drillpipe which is part of a drillstring carrying a drillbit, said drillstring rotatably driven in a working direction, which drillpipe contains a standard box tool joint at one end and a standard pin tool joint at the other end, which tool joints are of a diameter greater than the section of drillpipe between the two joints, and which drillpipe component is comprised of two elongated cylindrical half sections for clamping over at least a portion of the narrower section of drillpipe and which component, on its outer surface, contains at least one helical pumping chamber having a twist, when viewed in axial elevation, opposite to that in which said drillstring is rotatably driven in said working direction, said pumping chamber, when view is traverse section, having an undercut portion relative to the surface of the drillpipe component, said undercut portion defining a lip.
In a preferred embodiment of the present invention, the drillpipe component is manufactured from a polymeric material, such as a thermosetting plastic and is used in a cased borehole.
In another preferred embodiment of the present invention, the drillpipe component is manufactured from a metallic material and is used in an uncased borehole in a consolidated formation.
In both preferred embodiments of the present invention, the undercut defines a volute. The volute pumping chamber embodiment features a cross-section having at least two different radii of curvature, and has no sharp edges which could result in stress concentrations or which could damage the borehole mudcake.
Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation view of the drillpipe component of the present invention clamped onto a standard drillpipe.
FIG. 2 is an elevation view of a drillstring, constructed in accordance with the principles of the present invention.
FIGS. 3-5 illustrate axial cross-sectional views of several preferred embodiments of a drillpipe component constructed in accordance with the principles of this invention.
FIG. 6 is a fragmentary view of a cross-section of the drillpipe component of the invention illustrating the volute pumping chamber dimensions.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows drillpipe component 25 constructed in accordance with the principles of this invention. The drillpipe component is illustrated on a conventional drillpipe 12. Drillpipe component 10 has a left-handed helical pumping chamber 31. Standard American Petroleum Institute ("A.P.I.") box tool joint 16 and pin tool joint 18 are attached, respectively, to the upper end and lower ends of drillpipe 12. A circular passageway 14 is concentrically located within drillpipe 12 for carrying drilling mud to the drillstring bit. Drilling mud is pumped downward through this passageway by a drilling mud pump located near the entrance to the borehole, as described heretofore.
Referring now to FIG. 2, an elevation view of an illustrative embodiment of a drillstring 20, practicing the principles of the present invention, is disposed in a directionally drilled borehole 21. As shown in FIG. 2, borehole 21 comprises a vertical leg leading from the borehole entrance (not shown), a transition zone, a substantially horizontal leg and an annular passage defined by the borehole wall and the exterior of the drillstring. Drillstring 20 is comprised of drill bit 22, downhole mudmotor 23, drill collar 24 and drill pipe 25 containing the component of the present invention. The drillstring may, in addition, employ stabilizer units, not shown. Full length drillstring components 25 are joined by mating their respective threaded box and pin tool joints. The drillstring is engaged by a rotary table near the entrance of the borehole in a manner per se known. Drill bit 34, downhole mudmotor 23 and the assorted joint sections and stabilizer units are conventional devices and form no part of this invention. Rather, the invention resides in use of the drillpipe component containing the uniquely designed helical pumping chamber 31 (of FIG. 1 hereof) which chamber is cascaded upwards at each end of drillstring component 25 near the tool joint connection. A single helical groove is illustrated in FIG. 2, but it is to be understood that any number of grooves can be used to accomplish the turbo-pumping objectives of the invention. Five or more chambers spaced apart in equal relation around the periphery of drillpipe component 25 are expected to provide the optimum cross-section for flexibility and fatigue resistance.
Drillpipes on which the component of the present invention are practiced may be any conventional drillpipe. Such drillpipe is typically manufactured from high strength steel meeting A.P.I. metallurgy specifications. Drillstring component 25, and the drillpipe to which the component of the instant invention is attached are of standard size (e.g., 71/4" diameter for an 83/4" borehole) and length for a given application.
FIG. 2 illustrates the flexibility of drillpipe component 25 at borehole kick-off point 26.
FIGS. 3, 4, and 5 show a number of drillpipe component axial cross-sectional plan views illustrating the uniquely designed pumping chamber constructed in accordance with the present invention. FIG. 3 provides an axial cross-sectional view of drillpipe component halves 30 and 30a, having five pear-shaped or finger-like continuously curving undercut pumping chambers 31. The pumping chambers are undercut with respect to the cylindrical surface of the drillstring components, thereby forming a lip 32 associated with each pumping chamber. In the preferred embodiments shown in FIGS. 3-6, the pumping chamber forms a volute having at least two portions of different radii of curvature. FIG. 4 shows six volute pumping chambers in a drillstring component cross-section, while FIG. 5 shows eight volute pumping chambers in a drillstring component cross-section. Each of these figures shows the two halves being held together by bolts 51.
The two halves of the drillpipe component of the present invention can be manufactured from any appropriate material. Non-limiting types of materials which can be used include plastics, such as thermoset plastics, which preferably contain a strengthening filler component. Filler components may include such things as carbon black and fibers and filaments comprised of spun glass or carbon. It is preferred that the drillpipe components of the instant invention be comprised of a thermosetting plastic.
The two halves may be joined by any appropriate means including the use of bolts and locknuts only, or in conjunction with a hinge along one side.
Each of the drillpipe component cross-sections in FIGS. 3-5 has a central bore 33 through which the drilling mud is pumped to drill bit 22. The direction of twist of pumping chambers 31, indicated by the arrow in FIGS. 3-5, is counterclockwise when viewed in axial elevation (i.e., a left-hand twist, see FIG. 1), based on the convention that the drill is rotated in a clockwise direction. The surface of pumping chamber 31, when view in axial cross section, may define a tear-shape, or pear-shape having a continuously curved perimeter so as to minimize the creation of stress concentration points that might otherwise result in fracture of lip 32 or destruction of the wallcake, or mudcake, lining the borehole. The pumping chamber is characterized by having an undercut portion, with respect to the surface of the drillstring component, so that lip 32 is formed to overhang the pumping chamber, as shown in FIG. 6.
In the preferred embodiment configuration, the pumping chamber, when viewed in axial cross-section, defines a continuously curved volute having at least two portions with different radii of curvature. Referring again to FIG. 6, pumping chamber 31 is comprised substantially of two portions having radii of curvature "c" and "d". The precise configuration of the pumping chamber axial cross-section is not critical, provided that the radius of curvature of portion "d" of the volute is substantially smaller than that for portion "c". In one preferred embodiment, the ratio c to d is 3.25:1.
In an alternate embodiment, the shape of the volute is a mirror image across the radius A--A shown in FIG. 6. This embodiment of the helical volute pumping chamber is contemplated to have the advantage of increasing turbidity in the drilling mud present in the borehole-drillstring annulus, while having lower pumping capacity. Creating turbidity in the drilling mud located in the borehole-drillstring annulus can have important advantages as described hereinafter.
The helical pitch of the pumping chambers 31 (i.e., the distance between portions of the same groove measured on a line parallel to the drillpipe component longitudinal axis) will vary depending upon the number of pumping chambers employed and the volume of the pumping chambers. It is contemplated that the pitch of the spiral should not be less than that necessary to encircle the circumference of the drillpipe component over a length equal to 12 times the outer diameter of the drillstring component, and not more than that necessary to encircle same over a length 3 times such diameter. However, the velocity in the drillstring longitudinal direction of any point on the interior of the pumping chamber must exceed that of the velocity of the drilling mud in the adjacent borehole-drillstring annulus, within the range of drillstring rotation speeds.
It is also contemplated that the cross-sectional area of the pumping chambers 31 may equal from 5 percent to 60 percent of the cross-sectional area of a smooth surface drillpipe component of the same inner and outer diameters. The minimum cross-sectional area within each pumping chamber must be such that a cutting of the maximum size likely to be encountered in drilling a given subterranean formation will pass cleanly through the pumping chamber, i.e., without becoming stuck in the pumping chamber.
The pumping chamber 31 in drillpipe component provides a number of advantages over prior art spiral groove drillstring components and conventional circular cylinder drill collars when used in high-angle, directional and horizontal drilling applications. The helical volute pumping chambers act partly in a manner analogous to an Archimedean screw by propelling the cutting-laden drilling mud generated at the drill bit backwards and upwards toward the top of the borehole. Furthermore, as the drilling mud is propelled upward by the pumping chamber, it induces a dynamic flow field in the annulus. Rotation of the drillpipe component creates a partial suction at the bottom of the borehole tending to draw up additional amounts of drilling mud due to the localized underbalanced condition at the drill bit/formation interface, thus increasing the rate of penetration.
In conventional drilling applications, only about one-half of the borehole depth is attributable to the mechanical cutting energy of the drill bit; the balance of the earth cutting power is supplied by the hydrodynamic impact forces created by injecting the drilling mud through the drill bit jets. Drillstring component 25 harnesses the rotational energy of drillstring 20, which would otherwise be lost, for example, as heat, and uses that energy to increase the volumetric efficiency of the drilling rig. The turbo-pumping action induced by spiral pumping chamber 31 (of FIG. 1) enhances cuttings removal and provides a clear path for the drill bit to contact uncut formation, rather than pulverizing previous cuttings which heretofore were not quickly removed from the drill bit path. Consequently, significant increases in the rate of penetration of the drill bit and a concomitant increase in drill bit life may be realized.
Referring again to FIG. 1, pumping chamber 31 of drillpipe component 25 significantly reduces the incidence of differential sticking because pumping chamber 31 acts to equalize fluid pressure around the periphery of the drillpipe component. Also, since the drilling mud is free to flow through pumping chamber 31 to equalize any gradients around the drillpipe periphery, there is no longer a problem of lateral fluid pressure imbalance maintaining the drillstring in halting engagement with the borehole wall. Finally, since drillpipes incorporating the components of the present invention are not subject to drag induced by lesser degrees of differential sticking (i.e., downhole torque reduction), the drillstring can achieve higher rotary speeds with less concern about twistoff.
Finally, the configuration of pumping chamber 31 is designed to permit increased flexion of the drillstring component relative to previously known devices. Whereas, for example, a drillstring component designed in accordance with Hill et al. U.S. Pat. No. 4,811,800, based on the data contained in FIG. 10 of that patent, would experience twistoff within six hours (assuming a conservatively low rotary speed of 35 r.p.m. and a bend radius of 50 feet), it is contemplated that a drillpipe component constructed in accordance with the present invention, and having five or more helical pumping chambers, would have a service life of several hundred hours.
It is to be understood that the number of spiral pumping chambers 31 employed at equally spaced locations around the circumference of the drillpipe component may vary from one to many, and that precise configuration of the pumping chambers is not critical, provided that the pumping chambers preferably have a twist oriented in the direction opposite that of the drillstring rotation. Furthermore, the range of cross-sectional area of the drillpipe component that can be dedicated to the pumping chamber is limited at the lower end only by the minimum needed to induce a pumping action (dependent in part also upon the helical pitch) and at the upper limit by the minimum amount of metal required to maintain the torsional strength of the drillstring component.
EXAMPLE 1
For the volute pumping chamber shown in FIG. 6, wherein the dimensions a-f are: a=3.25"; b=1.50"; c=0.5"; e=0.19" and f=0.25", the cross-sectional area of the pumping chamber is about 2.0 in 2 .
Calculated values of the pumping capacity for a 30 foot long drillpipe component embodying the present invention, with the foregoing pumping chamber dimensions, and having a pitch of 1/10 turns per foot, are presented in Table 1 as a function of the number of volutes present on the drillpipe component periphery.
TABLE 1______________________________________ Pumping CapacityNumber of % Reduction GPM @ RPMVolutes in Area 10 RPM 25 RPM 50 RPM______________________________________1 7.6 5.5 13.8 27.63 22.9 16.5 41.4 82.85 38.3 27.5 69.0 138.06 46.0 33.0 82.8 165.68 61.3 44.0 110.4 221.8______________________________________
While the prior art helically grooved drillpipe components emphasize that the grooves serves to increase the load on the drill bit when used in directional and horizontal drilling applications, the counter-rotation twist of the drillstring of the present invention is particularly suitable for use with downhole mudmotors, since operation of invention drillstring component will not induce any "screw down" or other forces which might cause the mudmotor or bit to deviate from its intended path. Since the function of the mudmotor and assembly is to maintain a true course for the interpenetration of oilsand zones, extraneous forces introduced by the prior art drillstring components may be undesirable. In fact, such "screwing down" action may result in aggressive contact between these other prior art devices and the borehole wall, thereby destroying the wallcake and impeding progress.
Finally, the pumping capacity of the present invention, as represented in Table 1, gives a drillpipe component embodying the present invention the additional advantage of borehole cleaning in the event of a drilling mud pump shutdown or failure. With presently existing drillstring components, drilling mud pump shutdown can result in cuttings quickly settling out of suspension and packing in against the drillstring stabilizers, drill collars and bit, thereby impeding or preventing withdrawal of the drillstring. However, simply rotating a drillstring embodying the drillpipe component containing the pumping chambers of the present invention--using the rotary table or top drive--will keep the cuttings in suspension and pump cutting-laden drilling mud to the surface. Thus, a drillstring embodying the present invention features greatly enhanced retrievability, even in the event of drilling mud pump shutdown or failure.
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A component for attachment to a drillpipe which is part of a drillstring carrying a drillbit, said drillstring rotatably driven in a working direction, which drillpipe contains a standard box tool joint at one end and a standard pin tool joint at the other end, which tool joints are of a diameter greater than the section of drillpipe between the two joints, and which drillpipe component is comprised of two elongated cylindrical half sections for clamping over at least a portion of the narrower section of drillpipe and which component, on its outer surface, contains at least one helical pumping chamber having a twist, when viewed in axial elevation, opposite to that in which said drillstring is rotatably driven in said working direction, said pumping chamber, when view is traverse section, having an undercut portion relative to the surface of the drillpipe component, said undercut portion defining a lip.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application Nos. 2011-227907 and 2011-227913 filed in Japan on Oct. 17, 2011 and Oct. 17, 2011, respectively, the entire contents of which are hereby incorporated by reference.
TECHNICAL FIELD
[0002] The present invention relates to a silicone release coating composition of condensation reaction curing type.
BACKGROUND ART
[0003] There has long been known a method for producing a material releasable from sticky substances such as pressure-sensitive adhesive by forming a releasable cured film formed on a surface of a substrate such as paper, laminated paper, and plastic film. The material used for forming the releasable cured film is a silicone composition. For example, a silicone release coating composition of condensation reaction curing type, which is composed of silanol group-containing organopolysiloxane, organohydrogenpolysiloxane, and tin compound, was disclosed in JP-B S35-13709 (Patent Documents 1) and JP-B S36-1397 (Patent Documents 2).
[0004] The pioneering material mentioned above was followed by a composition of addition reaction curing type as disclosed in JP-B S46-26798 (Patent Document 3). This new composition soon came into general use on account of its better curability and longer pot life than the old condensation type. The addition curing type is still prevailing especially in the application for release paper which needs curing at a comparatively low temperature within a short time.
[0005] The coating composition of condensation reaction curing type mentioned above usually employs a tin compound in the form of alkyl tin which is superior in curing performance, colorless, liquid, and soluble in silicone. Unfortunately, this tin compound is toxic (to reproduction). Moreover, it is pointed out that the tin compound as a suspected environmental hormone is harmful to the environment, and hence there has been a movement to limit the use of the tin compound more strictly.
[0006] Despite its disadvantage mentioned above, the coating composition of condensation reaction curing type has advantages of finding use in an area where addition reaction curing type suffers from catalytic poison and of being cable of being used in mixture with a variety of other materials. Therefore, it is expected that the silicone release coating composition of condensation reaction curing type will find use in varied areas if it is relieved from problems with safety of tin catalyst and environmental load.
[0007] Consequently, much has been studied for the development of non-tin catalysts. Some examples are listed below:
[0008] quaternary phosphonium hydroxide compound, disclosed in JP-A S59-176326 (Patent Document 4);
[0009] quaternary ammonium ion compound, disclosed in WO 2008/081890 (Patent Document 5);
[0010] organic substance such as guanidine, disclosed in U.S. Pat. No. 3,719,633 (Patent Document 6), U.S. Pat. No. 4,180,462 (Patent Document 7), and JP-T 2011-506584 (Patent Document 8); and
[0011] natural mineral such as kaolin, disclosed in JP-T 2011-510103 (Patent Document 9).
[0012] Conventional metal compounds include titanium and zinc compounds. Recently proposed metal compounds are listed below:
[0013] Ir compound, disclosed in JP-T 2007-527932 (Patent Document 10);
[0014] Zr compound, disclosed in JP-A 2010-163602 (Patent Document 11);
[0015] Zn compound, disclosed in JP-T 2011-506738 (Patent Document 12);
[0016] Mo compound, disclosed in JP-T 2011-506744 (Patent Document 13); and
[0017] various metals such as Cu, Ag, B, Sc, Ce, Bi, Ge, and Mn, disclosed in JP-T 2011-506739 (Patent Document 14).
[0018] Such metal catalysts, however, are less common in the industry than tin catalysts because of their slow reaction rate, tendency toward gelation, poor catalytic effect, and high cost. These disadvantages prevent their use especially for the silicone release coating agent which needs curing at a comparatively low temperature within a short time.
CITATION LIST
[0000]
Patent Document 1: JP-B S35-13709
Patent Document 2: JP-B S36-1397
Patent Document 3: JP-B S46-26798
Patent Document 4: JP-A S59-176326
Patent Document 5: WO 2008/081890
Patent Document 6: U.S. Pat. No. 3,719,633
Patent Document 7: U.S. Pat. No. 4,180,462
Patent Document 8: JP-T 2011-506584
Patent Document 9: JP-T 2011-510103
Patent Document 10: JP-T 2007-527932
Patent Document 11: JP-A 2010-163602
Patent Document 12: JP-T 2011-506738
Patent Document 13: JP-T 2011-506744
Patent Document 14: JP-T 2011-506739
SUMMARY OF INVENTION
[0033] It is an object of the present invention to provide a silicone release coating composition capable of curing through condensation reaction involving dehydrogenation and dealcoholization, the composition being designed for coating onto a surface of a paper, a laminated paper and a plastic film and being able to form a non-tacky coating film with good releasability on the surface of various substrates.
[0034] In order to achieve the object above, the present inventors conducted a series of researches using a variety of materials. It has been found out that a composition providing good performance as a silicone release coating agent capable of curing through condensation reaction involving dehydrogenation and dealcoholization can be obtained if a non-tin metal compound catalyst is used in combination with a cocatalyst which is a specific nitrogen atom-containing compound or an oxygen multidentate ligand. This finding led to the present invention.
[0035] The present invention provides a following condensation reaction-curable silicone release coating composition.
[0000] [1] A silicone release coating composition of condensation reaction curing type comprising:
[0036] component (A) in an amount of 100 parts by weight which is an organopolysiloxane having at least two silanol groups in one molecule; component (B) which is composed of component (B-1) in an amount of 0.1 to 20 parts by weight which is an organohydrogenpolysiloxane having at least three SiH groups or three hydrogen atoms directly bonded to silicon atoms in one molecule, and/or component (B-2) in an amount of 0.1 to 20 parts by weight which is an organopolysiloxane having at least three hydrolyzable groups directly bonded to a silicon atom in one molecule, with component (B) being in such an amount that the number of moles of SiH groups and hydrolyzable groups as active groups therein is 1 to 200 times the number of moles of silanol amount in component (A);
[0037] component (C) in a catalyst quantity which is a compound of metal selected from magnesium, aluminum, titanium, chromium, iron, cobalt, nickel, copper, zinc, zirconium, tungsten, and bismuth, which functions as a condensation reaction catalyst; and
[0038] component (D) in an amount of 1 to 20 parts by weight which is either component (D-1), which is a cocatalyst of an organic compound having a bond between a nitrogen atom and an oxygen atom and/or a bond between a nitrogen atom and a sulfur atom through 1 to 3 carbon atoms, or component (D-2), which is a cocatalyst of an organic compound functioning as an oxygen multidentate ligand.
[0000] [2] The composition of [1], wherein component (D-1) is (I) one which has a molecular weight up to 10,000, (II) one which has a silicon atom-containing substituent in one molecule, or one which satisfies both of the conditions (I) and (II) mentioned above.
[3] The composition of [1] or [2], wherein component (D-1) is one selected from the following organic compounds (i) to (iv) and an organic compound formed by reaction between at least two of the organic compounds (i) to (iv):
[0039] (i) an isocyanate group-containing compound and a condensate thereof;
[0040] (ii) a reaction product of the isocyanate group-containing compound and a hydroxyl group-containing and/or amino group-containing compound;
[0041] (iii) a ring opening reaction product of the amino group-containing compound and an epoxy compound; and
[0042] (iv) a ring opening reaction product of the amino group-containing compound and an oxetane compound.
[0000] [4] The composition of [3], wherein component (D-1) is one of the organic compounds (i) to (iv) which has its oxygen atoms replaced partly or entirely by sulfur atoms and which is used alone or in combination with at least one of the organic compounds (i) to (iv).
[5] The composition of [1], wherein component (D-2) is any one of polybasic carboxylic acid, hydroxy acid, hydroxyketone, diketone, keto acid, and a substituted derivative thereof, which is a cocatalyst of an organic compound capable of functioning as a chelating agent.
[6] The composition of [5], wherein component (D-2) is any one of β-dicarboxylic acid, β-hydroxy acid, β-hydroxyketone, 1,3-diketone, β-keto acid, and a substituted derivative thereof.
[7] The composition of [6], wherein component (D-2) is any one of malonic acid, acetoacetic acid, acetylacetone, and a substituted derivative thereof.
[8] The composition of any one of [1] to [7], wherein the condensation reaction catalyst as component (C) is a compound of trivalent aluminum, trivalent iron, trivalent cobalt, divalent zinc, quadrivalent zirconium, or trivalent bismuth, which has an organic acid, alkoxide, or chelating agent as a ligand bonded thereto.
[9] The composition of [8], wherein the condensation reaction catalyst as component (C) is a compound of trivalent aluminum, trivalent iron, or trivalent bismuth, which has an organic acid or chelating agent as the ligand bonded thereto.
[10] The composition of [8], wherein the condensation reaction catalyst as component (C) is a compound of trivalent aluminum or trivalent iron, which has a multidentate ligand bonded thereto to be selected from organic acid having 5 to 20 carbon atoms and/or malonic acid, acetoacetic acid, acetylacetone, and a substituted derivative thereof.
[11] The composition of any one of [1] to [10], further comprising an organic solvent as component (E).
[12] The composition of any one of [1] to [11], wherein, when components (A) to (D) are dissolved in 1,900 parts by weight of toluene at the above-defined ranges of the blending amounts, a resulting solution has a viscosity up to twice its initial viscosity after standing at 25° C. for 24 hours.
ADVANTAGEOUS EFFECTS OF INVENTION
[0043] According to the present invention, even when using a non-tin metal compound catalyst which is generally inferior in curability and releasability to a tin compound catalyst, excellent curability and releasability can be accomplished. Moreover, the present invention provides a condensation reaction curable silicone release coating composition which is free of tin compounds involving potential problems with safety and environmental pollution. This composition is therefore expected to find new use in areas where an addition reaction curable silicone composition involves difficulties in application. It will also find new use because of its capability of mixing with a variety of materials.
[0044] The composition of the present invention forms a cured coating film which firmly adheres to a variety of substrates.
[0045] It is also superior in shelf life and pot life as well as workability and stability in properties.
DESCRIPTION OF EMBODIMENTS
Component (A): Organopolysiloxane
[0046] Component (A) is an organopolysiloxane having at least two hydroxyl groups each of which is directly bonded to a silicon atom in one molecule. The organopolysiloxane may have monovalent organic groups (other than the hydroxyl groups directly bonded to the silicon atoms) without specific restrictions. Such monovalent organic groups include, for example, alkyl groups (such as methyl group, ethyl group, propyl group, and butyl group), cycloalkyl groups (such as cyclopentyl group and cyclohexyl group), aryl groups (such as phenyl group and naphthyl group), and alkenyl groups (such as vinyl group and propenyl group), which are monovalent hydrocarbon groups having 1 to 10 carbon atoms. In the present invention, the organopolysiloxane should preferably contain organic groups other than the hydroxyl groups such that methyl group accounts for at least 80 mol % in them. In addition, the organopolysiloxane is not specifically restricted in molecular structure; however, a straight chain structure is basically desirable from the industrial point of view although a branched chain structure is also acceptable.
[0047] The organopolysiloxane as component (A) should preferably be one whose 30 wt % solution in toluene has an absolute viscosity of at least 50 mPa·s, more preferably 50 to 100,000 mPa·s, measured at 25° C. using a rotary viscometer.
[0048] Typical examples of component (A) are organopolysiloxanes represented by formulas (1-1) and (1-2) below, in which R is any one of hydroxyl groups, alkyl groups (such as methyl group, ethyl group, propyl group, and butyl group), cycloalkyl groups (such as cyclopentyl group and cyclohexyl group), aryl groups (such as phenyl group and naphthyl group), and alkenyl groups (such as vinyl group and propenyl group). R is also, in addition to monovalent hydrocarbon groups having 1 to 10 carbon atoms defined above, a siloxane residue represented by structural formulas (2-1) and (2-2), in which R 1 is an oxygen atom or one of alkylene groups having 1 to 6 carbon atoms (such as methylene group and ethylene group) and R is defined as above. In the formulas (1-1), (1-2), (2-1), and (2-2), α1 is 0 to 1,000, particularly 0 to 900, β1 is 50 to 9,000, particularly 60 to 9,000, α2 is 0 to 900, and β2 is 0 to 9,000. These numbers should be adequately selected so that there exist at least two hydroxyl groups in one molecule.
[0000]
[0000] (In the formulas above, Me is methyl group.)
Component (B-1): Organohydrogenpolysiloxane
[0049] Component (B-1) which is used as component (B) in the present invention is an organohydrogenpolysiloxane having at least three, preferably 4 to 1,000, hydrogen atoms directly bonded to silicon atoms (i.e., SiH groups) in one molecule. Except for this limitation, it may have any molecular structure of straight-chain type, branched chain type, or cyclic type. It is only necessary that the organohydrogenpolysiloxane as component (B-1) in the present invention is one which has an absolute viscosity ranging from several mPa·s to several tens of thousands of mPa·s measured at 25° C. using a rotary viscometer.
[0050] Typical examples of the organohydrogenpolysiloxanes are shown below.
[0000]
[0051] In the structural formulas and compositional formulas given above, Me is methyl group, Y and Z each are a group represented by the structural formula above, and a to q each are an integer in a range specified below.
a, e, g: 3 to 500, particularly 4 to 500 f, i, m: 0 to 500, particularly 0 to 400 b, c, d, h, j, k, n, o, p, q: 0 to 500, particularly 0 to 400
Component (8-2): Hydrolyzable Group-Containing Organopolysiloxane
[0055] Component (B-2) in the present invention is an organopolysiloxane which has at least three, preferably 3 to 1,000, hydrolyzable groups bonded to silicon atoms in one molecule. The hydrolyzable groups include alkoxy groups (such as methoxy group, ethoxy group, propoxy group, butoxy group, methoxyethoxy group, and isopropenoxy group) and acyloxy groups (such as acetoxy group), which are directly bonded to silicon atoms. The hydrolyzable groups may also partly include those which contain amino groups (such as ethylamino group), amide groups, oxime groups (such as ethylmethylbutanoxime group), or halogen atoms (such as chlorine atom and bromine atom).
[0056] Methoxy group, ethoxy group, propoxy group, and butoxy group are desirable as hydrolyzable groups from the standpoint of industry. Typical examples of organopolysiloxanes are represented by formulas below, in which r is 0 to 200, particularly 0 to 190, s is 0 to 1,000, particularly 0 to 900, Me is methyl group, and Et is ethyl group.
[0000]
[0057] Incidentally, alkoxy groups may be partly replaced by such groups as CH 3 COO—, CH 3 (C 2 H 5 )C═NO—, (C 2 H 5 ) 2 N—, CH 3 CO(C 2 H 5 )N—, and CH 2 ═(CH 3 )CO—.
[0058] The amount of organohydrogenpolysiloxane as component (B-1) of component (B) should be such that the amount (in terms of moles) of hydrogen atoms bonded to contained silicon atoms is 1 to 200 times, particularly 1 to 190 times, the total amount (in terms of moles) of hydroxyl groups contained in component (A). The hydrogen atoms bonded to the silicon atoms will be referred to as SiH group hereinafter. The amount of organopolysiloxane as component (B-2) of component (B) should be such that the amount (in terms of moles) of hydrolyzable groups bonded to silicon atoms is 1 to 200 times, particularly 1 to 190 times, the total amount (in terms of moles) of hydroxyl groups contained in component (A). If the amount of active groups (SiH groups and hydrolyzable groups) contained in component (B) is less than the lower limit mentioned above, the resulting silicone composition for release coating will be poor in curability. By contrast, the amount in excess of the upper limit is uneconomically wasted without any additional prominent effect and is detrimental to storage stability. The amount of component (B) should usually be 0.1 to 30 parts by weight, particularly 0.1 to 29 parts by weight, for 100 parts by weight of organopolysiloxane as component (A). Component (B) may be component (B-1) alone, component (B-2) alone, or a combination of components (B-1) and (B-2). It is also possible to use one which contains both SiH groups and hydrolyzable groups in one molecule.
Component (C): Curing Catalyst
[0059] The composition according to the present invention employs a curing catalyst as component (C). The catalyst is a condensation reaction curing catalyst intended to promote a so-called crosslinking reaction between component (A) and component (B), thereby forming a cured coating film. A compound of a metal selected from magnesium, aluminum, titanium, chromium, iron, cobalt, nickel, copper, zinc, zirconium, tungsten, and bismuth can be used as the condensation reaction curing catalyst. Preferable examples of the compounds include organic acid salts of trivalent aluminum, trivalent iron, trivalent cobalt, divalent zinc, quadrivalent zirconium, or trivalent bismuth, and metal compounds in the form of alkoxide or chelate. The organic acid salts include salts of octylic acid, lauric acid, and stearic acid. Alkoxide includes propoxide and butoxide, and chelate compounds include conjugate base of catechol, crown ether, polybasic carboxylic acid, hydroxy acid, and esters thereof, conjugate base of 1,3-diketone, conjugate base of β-keto acid ester, as well as multidentate ligand chelate compound. Different kinds of ligands may be bonded to one metal atom.
[0060] Compounds of aluminum, iron, and bismuth are easy to use and preferable because they often enable stable curing despite variation in compounding and working conditions.
[0061] Especially in a case where an organic compound is used which can function as component (D-2), which is an oxygen multidentate ligand mentioned later as a cocatalyst, the above-mentioned aluminum compound and iron compound are easy to use and desirable because of their stable curability insensitive to varied compounding and working conditions. Further preferable structures include trivalent chelate compound of aluminum or iron in which the multidentate ligand is malonic acid ester, acetoacetic acid ester, acetylacetone, or substituted derivative thereof. In addition, in the metal compound of trivalent aluminum or trivalent iron, an organic acid having 5 to 20 carbon atoms such as octylic acid can be preferably used, and the above-described multidentate ligand and organic acid may be bonded to one metal atom.
[0062] The substituted derivative mentioned above may be one in which a hydrogen atom contained in the compound mentioned above is replaced by any one of alkyl groups (such as methyl group and ethyl group), alkenyl groups (such as vinyl group and allyl group), aryl groups (such as phenyl group), halogen atoms (such as chlorine atom and fluorine atom), hydroxyl group, fluoroalkyl groups, ester group-containing group, ether-containing group, ketone-containing group, amino group-containing group, amide group-containing group, carboxylic acid-containing group, nitrile group-containing group, and epoxy group-containing group. Typical examples include 2,2,6,6-tetramethyl-3,5-heptanedione and hexafluoropentanedione.
[0063] The above-described condensation reaction curing catalyst may be used in a catalyst quantity, which ranges from 0.1 to 20 wt % (in terms of metal) for component (A) and can be arbitrarily determined depending on the curing conditions.
Component (D): Cocatalyst
[0064] According to the present invention, component (D) of the composition is a cocatalyt which is incorporated to improve the catalytic action of component (C). Component (D) is either component (D-1) or component (D-2). Component (D-1) is an organic compound constructed such that a nitrogen atom is bonded to an oxygen atom and/or sulfur atom through 1 to 3 carbon atoms. Component (D-2) is an organic compound which functions as the oxygen multidentate ligand.
[0065] When the bond is made through one carbon atom, this structure is represented by —O—C—N—, whose typical examples include cyanate group —O—C═N, trimer thereof known as cyanurate group, isocyanate group —N═C═O, dimer and timer thereof known as urethodione group and isocyanurate group, respectively, amide group —CO—NH—, carbamate group —O—CO—NH 2 , urethane group —O—CO—NH—, urea group —NH—CO—NH—,
[0000]
[0000] They may assume a cyclic structure as exemplified by cyclic iminoether (such as oxazoline, oxazole, and oxazine), cyclic imide (such as maleimide and phthalimide), and cyclic lactam (such as pyrrolidone). Preferable among these examples are those compounds derived from isocyanate groups. Other preferable compounds are their dimers, trimers, compounds derived therefrom, and products resulting from their reaction with a hydroxyl group- and/or amino group-containing compound.
[0066] Examples of the compound having a structure —O—C—C—N— include those compounds derived from ethanolamine. Ring-opening reaction between an amino group-containing compound and an epoxy compound is made by applying a production method of ethanolamine in which amine and ethylene oxide are reacted with each other, whereby various compounds having corresponding structures can be prepared.
[0067] Examples of the compound having a structure —O—C—C—C—N— include those compounds derived from 1,3-aminoalcohol. Ring-opening reaction between an amino group-containing compound and an oxetane compound is made by applying a production method of 1,3-aminoalcohol in which amine and oxetane are reacted with each other, whereby various compounds having corresponding structures can be prepared.
[0068] Component (D-1) may also include any organic compound which results from reaction between at least two of the above-mentioned compounds.
[0069] The compounds may have oxygen atoms (O) therein partly or entirely replaced by sulfur atoms (S). Such compounds may be prepared by using isothiocyanate, thiacyclopropane or thietane.
[0070] The compound as component (D-1) may be either or both of a first compound having a structure in which nitrogen atoms and oxygen atoms are bonded through carbon atoms and a second compound differing from the first one in that the oxygen atoms are partly or entirely replaced by sulfur atoms.
[0071] Moreover, component (D-1) is required to be readily soluble in the silicone composition of the present invention. This solubility depends on the structure and molecular weight of the compound. The higher the molecular weight, the poorer the solubility is. A desirable molecular weight is up to 10,000, particularly up to 5,000. The molecular weight given hereunder is the number-average molecular weight determined under the following conditions by gel permeation chromatography (GPC) that employs polystyrene as the reference substance.
[0072] [Measurement Conditions]
Developer: toluene Flow rate: 0.35 mL/min Detector: differential refractive index detector (RI) Column: TSKgel-G2000H×2, G3000H×1, G4000H×1, TSKguardcolumnH-L×1 (made by Tosoh Corp.) Column temperature: 40° C. Amount of sample injected: 20 μL (1 wt % toluene solution)
[0079] Incidentally, those compounds having Si atom-containing substituents in the molecule are desirable because of their good solubility. Examples of such substituents include silyl and siloxane groups represented by —SiR 1 m (OR 2 ) 3-m , —O—SiR 1 m (OR 2 ) 3-m , or —(SiR 1 o (OR 2 ) 2-o —O—) n —SiR 1 m (OR 2 ) 3-m , in which R 1 and R 2 each are an alkyl group, alkenyl group, or aryl group having 1 to 20 carbon atoms, particularly 1 to 10 carbon atoms, (such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, vinyl group, allyl group, propenyl group, butenyl group, and phenyl group), and m, n, and o are respectively 0 to 3, 1 to 10, and 0 to 2. These groups may exist in the molecule in the form of divalent (or polyvalent) substituent in which part of R 1 and R 2 function as bonds.
[0080] Component (D-1) should preferably be selected from those organic compounds defined in paragraphs (i) to (iv) below or those organic compounds which are obtained by reaction between at least two of the organic compounds below:
[0081] (i) an isocyanate group-containing compound and a condensate thereof;
[0082] (ii) a reaction product of the isocyanate group-containing compound and a hydroxyl group-containing and/or amino group-containing compound;
[0083] (iii) a ring opening reaction product of the amino group-containing compound and an epoxy compound; and
[0084] (iv) a ring opening reaction product of the amino group-containing compound and an oxetane compound.
[0085] Typical examples of component (D-1) in the present invention are represented by following formulas in which Me is methyl group and Et is ethyl group.
[0000]
[0086] On the other hand, component (D-2) is an organic compound which functions as the oxygen multidentate ligand typified by such compounds as polybasic carboxylic acid, hydroxy acid, hydroxyketone, diketone, keto acid, and substituted derivatives thereof. Preferable among these compounds are dicarboxylic acid, β-hydroxy acid, 1,3-diketone, β-keto acid, β-hydroxyketone, and substituted derivatives thereof. Their specific examples include malonic acid, acetoacetic acid, acetylacetone, and substituted derivatives thereof. Examples of the substituted derivatives include those derived from the above-mentioned compounds which have hydrogen atoms therein replaced by alkyl groups (such as methyl group and ethyl group), alkenyl groups (such as vinyl group and allyl group), aryl groups (such as phenyl group), acyl groups (such as benzoyl group), halogen atoms (such as chlorine atom and fluorine atom), hydroxyl group, fluoroalkyl groups, ester group-containing group, ether-containing group, ketone-containing group, amino group-containing group, amide group-containing group, carboxylic acid-containing group, nitrile group-containing group or epoxy group-containing group. Their specific examples include ethyl acetoacetate, 2,2,6,6-tetramethyl-3,5-heptanedionate, hexafluoropentanedionate, and benzoylacetoacetate. Particularly preferable among them are acetyl-acetone and their substituted derivative (such as 2,2,6,6-tetramethyl-3,5-heptanedione).
[0087] Although no elucidation has been made yet of the mechanism by which component (D-2) functions as a cocatalyst, it is assumed that aluminum or iron constituting the metal compound as component (C) easily reacts with ambient water to form hydroxides and such compounds contained as impurities or formed during use deteriorate the catalytic effect on account of their poor solubility. By the presence of component (D-2), it is considered that the oxygen multidentate ligand replaces hydroxyl group, thereby converting into a structure with high catalytic effect.
[0088] Another assumption is as follows. In a case where component (C) has a chelate compound as a ligand, the chelate compound (as the multidentate ligand) crosslinks at least two metal atoms, thereby forming a structure of high molecular weight. When components having such a structure increase, solubility is lowered and catalytic actions are deteriorated. This adverse effect, too, is counteracted by component (D-2) which disintegrates the crosslinking structure of metal atoms to give a new structure favorable for catalytic action.
[0089] According to the present invention, the cocatalyst as component (D) should be added in an amount of 1 to 20 parts by weight, preferably 1 to 19 parts by weight, for 100 parts by weight of component (A). With an amount less than the lower limit, the resulting composition will be poor in curability. With an amount more than the upper limit, the resulting composition will be poor in pot life and workability.
Component (E): Organic Solvent
[0090] An organic solvent as component (E) of the composition according to the present invention is incorporated for the purposes of good stability in a processing bath, good applicability to various substrates and adequate adjustment of coating weight and viscosity. Examples of the solvent include toluene, xylene, ethyl acetate, acetone, methyl ethyl ketone, ethanol, IPA, hexane, and heptane. They are used in any amount suitable for uniform dissolution of the composition. An adequate amount of component (E) is 10 to 1,900 parts by weight for 100 parts by weight of component (A). Component (E) may be omitted for some coating methods.
Component (F): Organic Compound Having Such a Structure that a Nitrogen Atom and an Oxygen Atom are Bonded Together Through a Carbon Atom
[0091] An organic compound having such a structure that a nitrogen atom (N) and an oxygen atom (O) are bonded together through 1 to 3 carbon atoms (C) may be incorporated in the composition according to the present invention. This organic compound is expected to increase the strength of the cured coating film and improve adhesion with the substrate. It includes, for example, compounds having an isocyanate group —N═C═O and derivatives thereof and compounds obtained by ring-opening reaction between an amino group-containing compound and an epoxy or oxetane compound. Preferable among them is one which additionally has a substituent group containing silicon (Si).
[0092] Typical examples of component (F) are shown below.
[0000]
[0093] The amount of component (F), if it is added, should be 1 to 20 parts by weight, preferably 1 to 19 parts by weight, for 100 parts by weight of component (A). Incidentally, component (F) is effective particularly in a case where the composition contains component (D-2) as the cocatalyst.
Additional Components
[0094] The composition according to the present invention may optionally be incorporated with any known additives such as slip agent, adhesion promoter, release control agent, pigment, leveling agent, and bath life extender as appropriate.
[0095] The composition according to the present invention may be readily produced by uniformly mixing components (A), (B), (C), and (D) mentioned above, optionally in combination with components (E) and (F) mentioned above. It is desirable to start the procedure by uniformly dissolving component (A) in component (E) and then mixing the resulting solution sequentially with components (B), (C), (D), and (F).
[0096] The composition according to the present invention is superior in pot life to the conventional one of condensation reaction curing type because it contains no tin catalyst. However, it should preferably be incorporated with component (C) immediately before coating so that it has a sufficiently long pot life.
[0097] The composition according to the present invention will be desirable from the standpoint of pot life and workability if it has a viscosity up to twice its initial viscosity when measured with a rotary viscometer after mixing with 1,900 parts by weight of toluene as component (E) and standing for 24 hours at 25° C.
[0098] The composition according to the present invention may be applied to such a substrate as paper, laminated paper, and plastic film, directly or after dilution with an adequate organic solvent, by any known coating method with a bar coater, roll coater, reverse coater, gravure coater, or air knife coater. Accurate thin film coating may be accomplished with an offset coater or multistage roll coater.
[0099] The composition according to the present invention may vary in coating weight depending on the type of the substrate. An adequate coating weight is 0.1 to 5.0 g/m 2 (in terms of solids). The coated substrate thus obtained is heated at 80 to 180° C. for 5 to 60 seconds so that the composition forms a cured film on the surface of the substrate. In this way there is obtained a release paper or release film as desired.
EXAMPLES
[0100] The invention will be described below in more detail with reference to Examples and Comparative Examples, which are not intended to restrict the scope thereof. Abbreviations Me and Et are methyl group and ethyl group, respectively, hereunder.
Example 1
[0101] First, component (A), which is 100 parts by weight of organopolysiloxane having a main skeleton composed of dimethylsiloxane units and having both ends of the molecular chain blocked with dimethylhydroxysilyl groups, characterized by that its 30 wt % solution in toluene has a viscosity of 10,000 mPa·s (measured with a rotary viscometer at 25° C.), was dissolved with stirring at 20 to 40° C. in component (E), which is 1,800 parts by weight of toluene. To the resulting solution was added components (B-1) and (D-1) with stirring at 20 to 40° C. for one hour. Component (B-1) is three parts by weight of methylhydrogenpolysiloxane composed of MeHSiO 2/2 units (95 mol %) and having both ends of the molecular chain blocked with trimethylsilyl groups, characterized by an absolute viscosity of 25 mPa·s. Component (D-1) is ten parts by weight of a compound represented by a formula below.
[0000]
[0102] Incidentally, component (D-1) was obtained from compounds represented by formulas below by reaction in equal molar amounts at 140° C. for six hours. It is composed mainly of a condensate of epoxy group and amino group, and it has an average molecular weight of 400.
[0000]
[0103] Immediately before application to a substrate, the desired composition was prepared by incorporating the above-described mixture with component (C), which is trivalent bismuth carboxylate, in an amount of 3 wt % in terms of bismuth for 100 wt % of component (A).
[0104] The thus obtained composition was uniformly applied to glassine paper by using a mayer bar, followed by curing under predetermined conditions (at 150° C. for 30 seconds). In this way there was obtained a sample for evaluation which has a coating weight of 1.0 g/m 2 (in terms of solids). The cured coating film was evaluated for characteristic properties according to a method mentioned later. The results of the evaluation are shown in Table 1.
Example 2
[0105] The same composition as in Example 1 was prepared except that component (D-1) was replaced by ten parts by weight of a compound represented by a formula below.
[0000]
[0106] Incidentally, component (D-1) was prepared from a compound represented by a formula below through condensation of three moles of isocyanate groups therein in a known way. It is a trimer having an average molecular weight of 600.
[0000]
Example 3
[0107] The same composition as in Example 1 was prepared except that component (D-1) was replaced by ten parts by weight of a compound represented by a formula below.
[0000]
[0108] Incidentally, component (D-1) was obtained from compounds represented by formulas below by reaction in equal molar amounts at 50° C. for six hours. It is composed mainly of a condensate of isocyanate group and amino group, and it has an average molecular weight of 350.
[0000]
Example 4
[0109] The same composition as in Example 1 was prepared except that component (D-1) was replaced by ten parts by weight of a compound represented by a formula below.
[0000]
[0110] Incidentally, component (D-1) was obtained from one mole each of compounds represented by formulas below.
[0000]
[0111] The first and second compounds were reacted with each other at 140° C. for six hours and the resulting intermediate compound was reacted with the third compound at 50° C. for six hours. The thus obtained compound has an average molecular weight of 600.
Example 5
[0112] The same composition as in Example 1 was prepared except that component (D-1) was replaced by ten parts by weight of a compound represented by a formula below.
[0000]
[0113] Incidentally, component (D-1) was obtained from one mole of a compound represented by a formula below
[0000]
[0000] and two moles of a compound represented by a formula below
[0000]
[0000] by reaction at 140° C. for six hours. The thus obtained compound has an average molecular weight of 700.
Example 6
[0114] The same composition as in Example 1 was prepared except that component (D-1) was replaced by ten parts by weight of a compound represented by a formula below.
[0000]
[0115] Incidentally, component (D-1) was obtained from one mole each of compounds represented by formulas below
[0000]
[0000] by reaction at 140° C. for six hours. The thus obtained compound has an average molecular weight of 400.
Example 7
[0116] The same procedure as Example 1 was carried out except that component (C) was replaced by iron tetraacetylacetonate in an amount of 3 wt % in terms of iron for 100 wt % of component (A).
Example 8
[0117] The same procedure as in Example 1 was carried out except that component (A) was replaced by another component (A) specified below and component (B-1) was replaced by component (B-2) specified below.
Component (A) for Replacement:
[0118] 100 parts by weight of organopolysiloxane having a main skeleton composed of dimethylsiloxane units (99.9 mol %) and blocked at both ends of the molecular chain with dimethylhydroxysilyl groups and also having hydroxymethylsiloxane units (0.01 mol %), characterized by that its 30 wt % solution in toluene has a viscosity of 15,000 mPa·s at 25° C.
Component (B-2):
[0119] five parts by weight of methylmethoxypolysiloxane which is a partial hydrolyzate condensate of MeSi(OMe) 3 and has a viscosity of 10 mPa·s.
Example 9
[0120] The same procedure as in Example 8 was carried out except that component (C) was replaced by another component (C) which is aluminum tetraacetylacetonate in an amount of 3 wt % (in terms of aluminum) for 100 wt % of component (A).
Example 10
[0121] The same procedure as in Example 8 was carried out except that component (C) was replaced by another component (C) which is iron tetraacetylacetonate in an amount of 3 wt % (in terms of iron) for 100 wt % of component (A).
Example 11
[0122] The same procedure as in Example 8 was carried out except that component (C) was replaced by another component (C) which is composed of aluminum tetraacetylacetonate in an amount of 1.5 wt % (in terms of aluminum) and trivalent bismuth carboxylate in an amount of 1.5 wt % (in terms of bismuth), both for 100 wt % of component (A).
Example 12
[0123] The same procedure as in Example 8 was carried out except that component (C) was replaced by another component (C) which is composed of iron tetraacetylacetonate in an amount of 1.5 wt % (in terms of iron) and trivalent bismuth carboxylate in an amount of 1.5 wt % (in terms of bismuth), both for 100 wt % of component (A).
Comparative Example 1
[0124] The same procedure as in Example 1 was carried out to prepare a sample for evaluation, except that component (D-1) was not added.
Comparative Example 2
[0125] The same procedure as in Example 1 was carried out to prepare a composition, except that component (D-1) was replaced by a compound represented by a formula below.
[0000]
Comparative Example 3
[0126] The same procedure as in Example 1 was carried out to prepare a composition, except that component (D-1) was replaced by a compound represented by a formula below.
[0000]
Comparative Example 4
[0127] The same procedure as in Example 1 was carried out to prepare a composition, except that component (D-1) was not added and component (C) was replaced by dioctyltin dicarboxylate in an amount of 3 wt % in terms of tin.
Comparative Example 5
[0128] The same procedure as in Example 8 was dioctyltin dicarboxylate to prepare a composition, except that component (D-1) was not added and component (C) was replaced by dioctyltin dicarboxylate in an amount of 3 wt % (in terms of tin) for 100 wt % of component (A).
[Method for Evaluating the Characteristic Properties of the Cured Coating Film]
(1) Curability
[0129] The silicone composition incorporated with a catalyst was applied to PE-laminated paper at a coating weight of 1.0 g/m 2 (in terms of solids), and the coated paper was heated at 130° C. for 30 seconds in a circulating hot air dryer. Thus there was obtained a sample for evaluation which has a cured coating film.
[0130] The sample was rated for curability according to following criteria by observing how the cured coating film changes in surface state after rubbing with a finger.
[0131] ◯: no clouding after heating at 130° C. for 30 seconds
[0132] Δ: slight clouding
[0133] x: dark clouding (or remaining uncured)
(2) Adhesion
[0134] The silicone composition incorporated with a catalyst was applied to PE-laminated paper at a coating weight of 1.0 g/m 2 (in terms of solids), and the coated paper was heated at 150° C. for 30 seconds in a circulating hot air dryer. Thus there was obtained a sample for evaluation which has a cured coating film.
[0135] After standing at 25° C. and 50% RH for one day, the sample was rated for adhesion according to following criteria by rubbing the surface of the cured coating film with a finger and checking it for peeling.
[0136] ◯: no peeling at all
[0137] Δ: partial peeling
[0138] x: easy peeling
(3) Releasability
[0139] The same sample as mentioned in (2) above for evaluation of adhesion was prepared. It was coated on its cured coating film with a sticking agent of acrylic solution type (“Oribain BPS-5127” from Toyo Ink Co., Ltd.). After heating at 100° C. for three minutes, the treated surface was laminated with wood-free paper having a basis weight of 64 g/m 2 , followed by pressing (twice) under a 2 kg roll and aging at 25° C. for 20 hours. The resulting sample was cut into a 5 cm wide strip. The strip was tested for 180° peel strength on a tensile tester at a peeling rate of 0.3 m/min. The peel strength is expressed in terms of force (N) required for delamination. The tensile tester is “Autograph DCS-500” made by Shimadzu Corporation.
(4) Remaining Adhesiveness
[0140] The cured coating film (which functions as a separator) was tested for remaining adhesiveness as follows. A piece of polyester tape (“Nitto 31B” made by Nitto Denko Co., Ltd.) was stuck to the surface of the cured coating film and kept pressed under a load of 20 gf/cm 2 at 70° C. for 20 hours. The tape was peeled off and stuck to a stainless steel plate. The tape was peeled off at an angle of 180° with respect to the surface of the stainless steel plate at a rate of 0.3 m/min, and the force required for peeling was measured. Meanwhile, the same procedure as above was carried out except that the cured coating film was replaced by a Teflon (registered trademark) plate. The ratio of the force measured in the first testing to the force measured in the second testing was calculated. The sample was rated as good (A), poor (B), and bad (C) according to the ratio which is at least 90%, 80 to 89%, and up to 79%, respectively.
(5) Pot Life
[0141] The coating solutions prepared in Examples and Comparative Examples were checked for appearance after standing at 25° C. for one day. Those with a good appearance were rated as good (A) and those with a poor appearance (due to increased viscosity, gelation, and precipitation) were rated as bad (C).
[0000]
TABLE 1
Results of Evaluation
Cur-
Ad-
Releas-
Remaining
Pot
No.
ability
hesion
ability
adhesiveness
life
Example
1
∘
∘
0.5
∘
∘
2
∘
∘
0.55
∘
∘
3
∘
∘
0.49
∘
∘
4
∘
∘
0.6
∘
∘
5
∘
∘
0.54
∘
∘
6
∘
∘
0.57
∘
∘
7
∘
∘
0.51
∘
∘
8
∘
∘
0.33
∘
∘
9
∘
∘
0.25
∘
∘
10
∘
∘
0.35
∘
∘
11
∘
∘
0.3
∘
∘
12
∘
∘
0.32
∘
∘
Comparative
1
x
∘
2.0
Δ
∘
Example
2
x
∘
2.0
Δ
∘
3
x
∘
1.2
Δ
∘
4
Δ
∘
0.6
∘
x
5
Δ
∘
0.3
∘
x
[0142] The present invention provides a composition which, without resorting to a tin-based catalyst, forms a release paper excellent in properties of a cured coating film and also exhibits good storage stability and workability.
Example 13
[0143] First, component (A), which is 100 parts by weight of organopolysiloxane having a main skeleton composed of dimethylsiloxane units and having both ends of the molecular chain blocked with dimethylhydroxysilyl groups, characterized by that its 30 wt % solution in toluene has a viscosity of 10,000 mPa·s (measured with a rotary viscometer at 25° C.), was dissolved with stirring at 20 to 40° C. in component (E), which is 1,800 parts by weight of toluene. To the resulting solution was added components (B-1) and (D-2) with stirring at 20 to 40° C. for one hour. Component (B-1) is three parts by weight of methylhydrogenpolysiloxane composed of MeHSiO 2/2 units (95 mol %) and having both ends of the molecular chain blocked with trimethylsilyl groups, characterized by an absolute viscosity of 25 mPa·s. Component (D-2) is five parts by weight of acetylacetone.
[0144] Immediately before application to a substrate, the desired composition was prepared by incorporating the above-described mixture with component (C), which is trivalent iron triacetylacetonate, in an amount of 3 wt % in terms of iron for 100 wt % of component (A).
[0145] The thus obtained composition was uniformly applied to glassine paper by using a mayer bar, followed by curing under predetermined conditions (at 150° C. for 30 seconds). In this way there was obtained a sample for evaluation which has a coating weight of 1.0 g/m 2 (in terms of solids). The cured coating film was evaluated for characteristic properties according to the method mentioned above. The results of the evaluation are shown in Table 2.
Example 14
[0146] First, component (A), which is 100 parts by weight of organopolysiloxane having a main skeleton composed of dimethylsiloxane units (99.9 mol %) and hydroxymethylsiloxane units (0.01 mol %) and having both ends of the molecular chain blocked with dimethylhydroxysilyl groups, characterized by that its 30 wt % solution in toluene has a viscosity of 15,000 mPa·s (measured with a rotary viscometer at 25° C.), was dissolved with stirring at 20 to 40° C. in component (E), which is 1,800 parts by weight of toluene. To the resulting solution was added components (B-2) and (D-2) with stirring at 20 to 40° C. for one hour. Component (B-2) is five parts by weight of methylmethoxypolysiloxane having a viscosity of 10 mPa·s, which is a partial hydrolyzate condensate of MeSi(OMe) 3 . Component (D-2) is five parts by weight of acetylacetone.
[0147] Immediately before application to a substrate, the desired composition was prepared by incorporating the above-described mixture with component (C), which is dipropoxy aluminum trivalent ethylacetoacetate, in an amount of 3 wt % in terms of aluminum for 100 wt % of component (A).
[0148] The thus obtained composition was uniformly applied to glassine paper by using a mayer bar, followed by curing under predetermined conditions (at 150° C. for 30 seconds). In this way there was obtained a sample for evaluation which has a coating weight of 1.0 g/m 2 (in terms of solids). The cured coating film was evaluated for characteristic properties according to the method mentioned above. The results of the evaluation are shown in Table 2.
Example 15
[0149] The same procedure as in Example 14 was carried out except that component (C) was replaced by aluminum trivalent triacetylacetonate in an amount of 3 wt % (in terms of aluminum) for 100 wt % of component (A) and component (D-2) was replaced by acetylacetone in an amount of five parts by weight.
Example 16
[0150] The same procedure as in Example 13 was carried out except that component (C) was replaced by iron trivalent octylate in an amount of 4 wt % (in terms of iron) for 100 wt % of component (A) and component (D-2) was replaced by acetylacetone in an amount of five parts by weight, and a compound represented by a formula below was further added as component (F) in an amount of five parts by weight.
[0000]
Example 17
[0151] The same procedure as in Example 14 was carried out except that component (C) was replaced by zinc divalent diacetylacetonate in an amount of 5 wt % (in terms of zinc) for 100 wt % of component (A) and component (D-2) was replaced by acetylacetone in an amount of five parts by weight, and a compound represented by a formula below was further added as component (F) in an amount of five parts by weight.
[0000]
Example 18
[0152] The same procedure as in Example 14 was carried out except that component (C) was replaced by a combination of dibutoxyzirconium quadrivalent diacetylacetonate in an amount of 1.5 wt % (in terms of zirconium) for 100 wt % of component (A) and iron trivalent octylate in an amount of 1.5 wt % (in terms of iron) for 100 wt % of component (A), and component (D-2) was replaced by ethyl acetoacetate in an amount of five parts by weight.
Comparative Example 6
[0153] The same procedure as in Example 13 was carried out except that component (D-2) was not added.
Comparative Example 7
[0154] The same procedure as in Example 14 was carried out except that component (D-2) was not added.
Comparative Example 8
[0155] The same procedure as in Example 13 was carried out except that component (D-2) was not added and component (C) was replaced by dioctyltin dicarboxylate in an amount of 3 wt % in terms of tin.
[0000]
TABLE 2
Results of Evaluation
Cur-
Ad-
Releas-
Remaining
Pot
No.
ability
hesion
ability
adhesiveness
life
Example
13
∘
∘
0.35
∘
∘
14
∘
∘
0.26
∘
∘
15
∘
∘
0.25
∘
∘
16
∘
∘
0.33
∘
∘
17
∘
∘
0.32
∘
∘
18
∘
∘
0.36
∘
∘
Comparative
6
x
∘
1.2
Δ
∘
Example
7
x
∘
0.8
Δ
∘
8
Δ
∘
0.3
∘
x
[0156] The present invention provides a composition which, without resorting to a tin-based catalyst, forms a release paper excellent in properties of a cured coating film and also exhibits good storage stability and workability.
[0157] Japanese Patent Application Nos. 2011-227907 and 2011-227913 are incorporated herein by reference.
[0158] Although some preferred embodiments have been described, many modifications and variations may be made thereto in light of the above teachings. It is therefore to be understood that the invention may be practiced otherwise than as specifically described without departing from the scope of the appended claims.
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Disclosed herein is a silicone release coating composition of condensation reaction curing type including: (A) an organopolysiloxane having at least two silanol groups in one molecule; (B) (B-1) an organohydrogenpolysiloxane having at least three SiH groups in one molecule, and/or (B-2) an organopolysiloxane having at least three hydrolyzable groups directly bonded to a silicon atom in one molecule; (C) a compound of metal selected from Mg, Al, Ti, Cr, Fe, Co, Ni, Cu, Zn, Zr, W, and Bi, which functions as a condensation reaction catalyst; and (D) (D-1) a cocatalyst of an organic compound having a bond between a nitrogen atom and an oxygen atom and/or a bond between a nitrogen atom and a sulfur atom through 1 to 3 carbon atoms, or (D-2) a cocatalyst of an organic compound functioning as an oxygen multidentate ligand.
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OBJECT OF THE INVENTION
The present invention relates to a modular machine for spinning and doubling with individual transmission elements for spindles, with a continuous and individual conical or double conical folding system, by means of conventional asynchronous alternative current motors controlled by frequency converters and programmed by a control or microprocessor unit.
BACKGROUND OF THE INVENTION
The textile industry uses two types of continuous spinning and doubling, machines which, among other elements, are provided basically with some elements, called spindles, in a number ranging from five to several hundred units in each machine. The spindles turn continuously at the same speed, driven by only one electric motor by means of gear or pulleys assembly. Also, each spindle can be driven by an individual electric motor, with all motors controlled by a frequency variation unit so that all spindles turn at a same speed.
Although these machines have a high efficiency, all of their spindles turn at the same speed. Consequently, they all have to use the same thread type and are unable to combine different thread types in order to perform simultaneous short operations. Therefore, when it is necessary to produce different spinning and doubling operations, it is necessary to adapt the machine to the new process, causing an increase in production costs.
Furthermore, in spinning, doubling, textile spinning, spool roving frame, spool doubling, and similar machines, the thread obtained is stored in spinning bobbins, while the process for doubling the final product has suffered changes. The conventional process consist of the so called “reel” doubling, where the product is wound around a cylindrical reel provided in its upper and lower sides, with rims to prevent the thread from separating from the cylinder. This process had several inconveniences. For example, to carry out the unfolding of the thread in the process, it was necessary to turn the reel to avoid the breakage of the thread due to the strain caused by the pulling of the bobbin. Another inconvenience is that the unfolding had to be performed perpendicularly to the turning axis, in order to avoid thread breakage due to fouling in the bobbin upper rim.
A new reel type was later developed, which was known as “conventional conical.” This reel type reduced the upper rim to a diameter slightly larger than that of a central axis, so that the bobbin obtained had a mixed shape, with a conical upper portion. With this new pattern, although some of the previous inconveniences of the previous “reel” type model were eliminated, some problems remained. For example, in order to identify the bobbin pattern, it is necessary to match the cone angle with the number of coats required to obtain the required configuration. It will also be necessary to repeat such process for each reel type provided in the spinning machine, in the case that thread of different types and thicknesses are used, thus affecting the machine efficiency. Another inconvenience is that, when finishing a manufacturing cycle, the machine stops completely, and therefore all spindles stop turning even if they have not completed their process. As a result, time is wasted. Additionally, it is not possible to have bobbins with the same pattern when processing different products in the different spindles of spinning, doubling, textile spinning, spool roving frame, spool doubling, and similar machines.
SUMMARY OF THE INVENTION
With the purpose to prevent all serious inconveniences indicated above, when it is necessary to spin or double small amounts of product and to avoid wasting time relating to machine preparation, an improved modular machine for spinning and doubling with elements for spindles individual transmission has been developed. The invention also relates to a new system for doubling threads and welts as a continuous and individual conical or double conical folding system with a corresponding programming and control unit.
The modular machine for spinning and doubling with elements for spindles individual transmission with a continuous and individual conical or double conical folding system is made of a frame which includes two metal cabinets, one on a left side and one on a right side. The frame has a vertical cubic shape, made preferably in steel plate. The exterior of each cabinet has a pivoting access door. The central portion of the frame connects the two cabinets, fastened by bolts, is provided with cross bars made preferably of welded steel tubes, which act as a support for the different moving elements that will be described hereinafter.
The central portion of the frame contains within the space between both cabinets and held by the crossing tubes, preferably between one and thirty spinning or folding spindles, each having its own driving means. The spindles turn vertical to the axis on which the different types of spinning or folding reels will be mounted. The spindles are held by a twin roller system, of the ball bearing type. The upper bearing unit is packed in connection with a synthetic rubber ring to absorb the radial vibrations, and the lower bearing unit is mounted on a swinging support that is allowed to be displaced radially.
The spindle bottom part has fastened to it a pulley arranged to receive a transmission flat belt, for connection to the output of an induction electrical motor mounted on a pair of crossing tubes placed in the back side of frame.
A ring rail, having a vertical up and down displacement, on which a sliding piece rotates to create the twisting of the thread, is mounted coaxially on the spindle head. Above this ring rail, there is a thread guide having a similar movement but with a different speed. The thread guide guides the different threads towards the sliding piece that comes from the hake box or feeding assembly.
The feeding assembly for each spindle comprises a pair of feeding rollers, an inlet thread roller and a pressure cylinder. The feeding rollers, made preferably of chromed carbon steel, are driven by means of two horizontal shafts, which are also driven, through a flat belt transmission system, by an alternate current motor. The current motor is controlled by a conventional frequency variator. The variator is controlled by a potentiometer. The entire feeding assembly is located in the cabinet. The shafts are made of carbon steel and go through one cabinet to the other, and are supported by the cabinets. One shaft is located vertically above the other, and the shafts are connected to each other by means of a chain that makes them turn in the same direction. The pressure roller is located between the two feeding rollers and exerts a pressure on the thread in order to obtain a better draw. The pressure roller is held by ball bearings. The pressure arm is also fastened by bearings to another vertical shaft placed on top of those supported by the feeding rollers. The pressure arm is allowed to move radially when actuated by a pneumatic piston as to exert more or less pressure on threads moving through the pressure roller and feeding rollers. The pneumatic pistons acting on the pressure rollers of the feeding system in each spindle are driven by the pressured air flow coming from the air pressure piping system, with pressure regulated by a pressure control valve located in the cabinet.
In the modular machine for spinning and doubling with elements for spindle individual transmission with conical or double conical continuous and individual folding system, spindles are the main elements that are in continuous movement, and are able to turn at different speeds. The ring rail has a vertical up and down movement, with the sliding pieces and thread guides turning around and having, as in the case of the ring rail, a vertical up and down movement.
Each spindle turns around its own shaft driven by an alternate current induction motor by means of a belt, preferably of the flat type with interior teeth. Each motor is individually controlled by a frequency variator, of the conventional, vectorial or other type, which is programmed independently for each spindle by means of a potentiometer located in each spindle control panel, so that each spindle can turn at a different speed and have an opposite turning direction.
The ring rail can move vertically along two vertical guides, one in each side cabinet. The guides are of cylindrical shape and are made of carbon steel and fastened in the bottom to each cabinet forming the machine frame. The ring rail moves vertically up and down with a stroke equivalent to the spindle reel height, and can regulate the length of the stroke. The thread guides move above the ring rail, following a similar motion pattern, along the guides.
The ring rail as well as the thread guides are driven by an alternate current electric motor, provided with a speed variator of the manual regulation disc type. The variator transmits the turning movement to a speed reduction unit by means of the flat teethed belt. The output of the reduction unit is a horizontal shaft driving two drums with a different diameter on which steel cables are wound which hold the thread guides and the ring rail. The vertical up and down displacement is created as a consequence of the reverse in the motor turning direction, by means of the control provided by limit switches mounted on the drums. The thread guides and the ring rail are driven by the same means and the same motor with reduction unit, so that they all have the same frequency of movement.
The feeding rollers are mounted on two horizontal cross shafts vertically one on top of the other, and are driven through a flat belt transmission system by an alternate current motor controlled by a conventional frequency variator which, in turn, is controlled by a potentiometer. The turning movement is transmitted between both of them by means of a driving chain, so that both shafts turn in the same direction.
The driving motor as well as the frequency variator and the control potentiometer are located in the cabinet. Finally, the swing arm of each pressure roller is actuated by means of a pneumatic cylinder.
For a better understanding of the new continuous, individual conical or double conical folding system, first we will explain the process to obtain a conventional simple conical folding as it is used now. A conventional reel, comprising a cylindrical central body with its bottom provided with a disc having a diameter between two and five times the central body diameter to support the processed thread, will be inserted in spindles of a spinning and doubling machine. The upper part of the reel has another disc, with a diameter slightly larger than that of the central body. The processed thread is inserted in the central body bottom part of the reel, driving the spinning and doubling machine so that the reel turns, driven by the spindle. By means of the up and down displacement of the sliding piece, driven by the ring rail in which the processed thread is inserted, the thread will be wound or folded around the reel in an upwards direction. As a result, once the reel central body is covered with a first coat, a second coat is folded in a downwards direction. This process is repeated successively to get a diameter slightly smaller than that of a reel bottom disc, in a manner such that each coat presents a height slightly smaller than the previous coat. The result is a mixed pattern bobbin, in which approximately the lower two-thirds of the bobbin has a cylindrical shape and the upper one-third has a truncoconical shape resulting in folded material having an improved stability.
With the new continuous, individual, conical or double conical folding system, the process to obtain a bobbin is totally different from the conventional process. In the conventional process, the thread or welt is folded in accordance with a bobbin simple pattern, with most of its length being of cylindrical shape and truncoconical upper portion. In contrast, with the new continuous, individual, conical or truncoconical folding system, the folding pattern corresponds to a bobbin made up of multiple concentric cylinders and truncocones, forming assemblies called “subcycles” Each of the subcycles comprises a smaller given number of thread or welt coats, with respect to the conventional system, and each subcycle has a height slightly lower than that of a previous subcycle. When the assembly has a given number of subcycles, it is called a “repeated great cycle”.
With this improvement, the modular machine for spinning and doubling with individual transmission elements for spindles is provided with a control unit comprising a microprocessor. The microprocessor enables the machine to program, on a display, the length required to be stored in each reel, the reel length, the height (h) of the cone or truncocone, and by means of a display restricted to the user, the number of subcycles (m) and number of thread or welt coats in each subcycle (n) in accordance with the features of the processed products. The difference in height between a coat and next coat (Ca) and the difference in height between a subcycle and next subcycle (Cb), computed by means of the microprocessor algorithm, establishes the corresponding parameters.
Also, the microprocessor provides the machine with the capability to program different bobbin shapes, such as single cone, double cone and cylinder. All of these patterns can be obtained under the same process of subcycles and coats as previously described.
With the improvement introduced with the new control unit, the spinning machine, doubling machine, textile spinning, spool roving frame, spool doubling machine, and similar machines, have the capacity to apply the above described programs individually to each spindle of the machine.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention, a preferential embodiment of the improved modular spinning and doubling machine with individual transmission elements for spindles is shown in the drawings.
FIG. 1 is a front view of the modular spinning and doubling machine with individual transmission elements for spindles with a continuous, individual, conical or double conical folding system.
FIG. 2 is a plan view of the modular spinning and doubling machine with individual transmission elements for spindles with continuous, individual, conical or double conical folding system.
FIG. 3 is a sectional view of an assembly according to the invention.
FIG. 4 is a sectional view of a spindles bearing system according to the invention.
FIG. 5 shows front and plan views of a side of a cabinet according to the invention.
FIG. 6 shows front and plan views of a side of a cabinet according to the invention.
FIG. 7 is a front view of a cylindrical reel with two identical discs.
FIG. 8 is a front view of a reel folded in accordance with a conventional process.
FIG. 9 is a front schematic view of a continuous conical folding process.
FIG. 10 is a front view of a bobbin which has been configured in accordance with the continuous conical folding process.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The modular spinning and doubling machine with individual transmission elements for spindles with continuous, individual, conical or double conical folding system is made of a frame composed by two metal cabinets, one at the left ( 2 ) and the other at the right ( 1 ) hand side. The frame has a vertical cubic shape, made preferably in steel plate. The exterior of each cabinet has a pivoting access door. The central portion of the frame, connecting the two cabinets fastened by bolts, is provided with cross bars made preferably of welded steel tubes which support moving elements described hereinafter.
The central portion of the frame can contain, within the space between both cabinets ( 1 , 2 ) and held by the cross tubes ( 4 ), between one and thirty spinning or folding spindles ( 5 ), each having its own driving means. The spindles ( 5 ) are turning vertical to the axis on which the different types of spinning or folding reels will be mounted. The spindles ( 5 ) are held by a twin roller system of the ball bearing type. The upper bearing unit ( 8 ) is packed in connection with a synthetic rubber ring ( 9 ) to absorb the radial vibrations, and the lower bearing unit ( 10 ) is mounted on a swinging support ( 11 ) that is allowed to be displaced radially.
The spindle bottom part is fastened to a pulley ( 12 ) that is arranged to receive a transmission flat belt( 13 ), for connection to the output of an induction electrical motor ( 14 ) mounted on a pair of crossing tubes placed in the back side of the frame.
A ring rail ( 15 ), having a vertical up and down displacement, on which a sliding piece ( 16 ) rotates to create the twisting of the thread, is mounted coaxially on the spindle ( 5 ) head. Above this ring rail ( 15 ), there is a thread guide ( 17 ) having a similar movement but with a different speed. The said thread guide having the purpose of guiding the different threads towards the sliding piece ( 15 ) coming from the hake box or feeding assembly.
The feeding assembly for each spindle comprises a pair of feeding rollers ( 19 ), an inlet thread roller ( 18 ) and a pressure cylinder ( 21 ). The feeding rollers ( 19 ), are made preferably of chromed carbon steel, and are driven by means of two horizontal shafts ( 22 ), which are also driven, through a flat belt ( 23 ) transmission system by an alternate current motor ( 24 ) controlled by a conventional frequency variator, controlled by the control unit or microprocessor ( 29 ). The shafts are made of carbon steel and go through from one cabinet to the other supported by the cabinets. One shaft is located vertically above the other. The shafts are connected to each other by means of a chain ( 25 ) that makes them turn in the same direction. The pressure roller ( 21 ) is located between the two feeding rollers ( 19 ) and exerts a pressure on the threads ( 26 ) in order to obtain a better draw. The pressure roller is held by means of ball bearings. The pressure arm ( 20 ) is also fastened by means of bearings to another horizontal shaft ( 27 ) placed on top of those supported by the feeding rollers ( 19 ). The pressure arm ( 20 ) is allowed to move radially when actuated by a pneumatic piston ( 28 ) as to exert more or less pressure on threads moving through the pressure roller ( 21 ) and feeding rollers ( 19 ). The pneumatic pistons ( 26 ) acting on the pressure rollers ( 21 ) of the feeding system in each spindle are driven by the pressured air flow coming from the air pressure piping system, with pressure regulated by a pressure control valve located in the left hand side cabinet.
In the modular machine for spinning and doubling with elements for spindle individual transmission with conical or double conical continuous and individual folding system, spindles ( 5 ) are the main elements that are in continuous movement, and are able to turn at different speeds. The ring rail has a vertical up and down movement, with the sliding pieces ( 16 ) and thread guides ( 17 ) turning around and having, as in the case of the ring rail ( 15 ), a vertical up and down movement, the feeding rollers ( 19 ), the pressure rollers ( 21 ) and the inlet thread rollers ( 18 ).
Each spindle ( 5 ) turns around its own shaft, driven by an alternate current induction motor ( 14 ) by means of a belt ( 13 ), preferably of the flat type with interior teeth. Each motor ( 14 ) is individually controlled by a frequency variator, preferably of the conventional, vectorial or other type, which is programmed independently for each spindle ( 5 ) by means of the control unit or microprocessor ( 29 ) located in each spindle control panel, so that each spindle can turn at a different speed and have an opposite turning direction.
The ring rail ( 15 ) can displace vertically along two vertical guides ( 30 ), one in each side cabinet. The guides ( 30 ) are of cylindrical shape and are made of carbon steel and fastened in the bottom to each cabinet ( 1 , 2 ) forming the machine frame. The ring rail ( 15 ) moves vertically up and down with a stroke equivalent to the spindle reel height, so that it is possible to regulate the length of said stroke. The thread guides ( 17 ) move above the ring rail, following a similar motion pattern, along the guides.
The ring rail ( 15 ) as well as the thread guides ( 17 ) are driven by an alternate current electric motor ( 31 ) provided with a speed variator ( 32 ) of the manual regulation disc type. The variator ( 32 ) transmits the turning movement to a speed reduction unit ( 34 ) by means of the flat teethed belt ( 35 ). The output of the reduction unit is a horizontal shaft ( 36 ) driving two drums ( 37 ) with different diameters, on which steel cables ( 38 ) are wound which hold the thread guides ( 17 ) and the ring rail ( 15 ). The vertical up and down displacement is created as a consequence of the reverse in the motor ( 31 ) turning direction by means of the control provided by limit switches mounted on the drums. The thread guides ( 17 ) and the ring rail ( 15 ) are driven by same means and the same motor with reduction unit, so that they all have the same frequency of movement.
The feeding rollers ( 19 ) are mounted on two horizontal cross shafts ( 27 ) vertically, one on top of the other, and are driven through a flat belt transmission system by an alternate current motor ( 24 ) controlled by a conventional frequency variator, controlled by a control unit or a microprocessor ( 29 ). The turning movement is transmitted, between both of them by means of a driving chain ( 25 ) so that both shafts turn in the same direction.
For a better understanding of the new continuous, individual conical or double conical folding system, first we will explain the process to obtain a conventional simple conical folding as it is used now. A conventional reel ( 7 ), comprising a cylindrical central body ( 53 ) with its bottom provided with disc having a diameter from between two and five times of the central body diameter to support the processed thread, will be inserted in spindles ( 5 ) of spinning and doubling machine. The upper part of the reel has another disc with a diameter slightly larger than that of the central body ( 53 ). The processed thread is inserted in the central body ( 53 ) bottom part of the reel ( 7 ), driving the spinning and doubling machine so that the reel ( 7 ) turns, driven by the spindle. By means of the up and down displacement of the sliding piece ( 16 ), driven by the ring rail ( 15 ) in which the processed thread is inserted, the thread will be wound or folded around the reel ( 7 ) in an upwards direction so that once the reel central body is covered with a first coat, a second coat is folded in a downwards direction. This process is repeated successively to get a diameter slightly smaller than that of a reel bottom disc, in a manner such that each coat presents a height slightly smaller to that of the previous coat, as to obtain a mixed pattern bobbin, with approximately the lower two-thirds of the bobbin having a cylindrical shape and approximately the upper one-third of the bobbin having a truncoconical shape, resulting in folded material having an improved stability.
With the new continuous, individual, conical or double conical folding system, the process to obtain a bobbin, as shown in FIG. 9, is totally different from the conventional process, shown in FIG. 8 . In the conventional process of FIG. 8, the thread or welt is folded in accordance with a bobbin simple pattern, with most of its length having a cylindrical shape and a trunco-conical upper portion, while with the new continuous, individual, conival or trunco-conical folding system the folding pattern corresponds to a bobbin made up of multiple concentric cylinders and trunco-cones, forming assemblies called “subcycles” ( 45 ). Each of the subcycles ( 45 ) has a smaller given number of thread or welt coats ( 44 ) relative to the conventional system, and each subcycle ( 45 ) has a height slightly lower than that of a previous subcycle. The assembly having a given number of sub cycles is called a “repeated great cycle” ( 46 ).
With this improvement, the modular machine for spinning and doubling with individual transmission elements for spindles is provided with a control unit ( 29 ) comprising a microprocessor which enables the machine to program, on a display, the length required to be stored on each reel ( 7 ), the reel length, the height (h) ( 49 ) of the cone or trunco-cone, and by means of a display restricted to the user, the number of subcycles (m) and the number of thread or welt coats in each subcycle (n) in accordance with the features of the processed products.
The difference in height between a coat and next coat (Ca) ( 48 ) and the difference in height between a subcycle and a next subcycle (Cb) ( 47 ), computed by means of the microprocessor algorithm, establishes the corresponding parameters.
Also, the microprocessor ( 29 ) provides the machine with the ability to program different bobbin shapes, including single cone, double cone, and cylinder. All of these patterns are obtained through the same process of subcycles and coats as previously described.
With the improvement introduced with the new control unit ( 29 ), the spinning machine, doubling machine, textile spinning, spool roving frame, spool doubling machine and similar machines, have the capacity to apply the above described programs, individually to each spindle of the machine.
In order to start the process, an operation cycle is programmed for each spindle by means of the display ( 29 ) of the control unit or microprocessor by introducing the following data: twist degree, bobbin shape (simple cone, double cone or straight), length to be processed in each spindle, conical ( 49 ) and the reel height ( 50 ).
Subsequently, the different threads ( 26 ) are inserted to form the final thread or welt through the inlet rollers ( 18 ), then feed through the feeding rollers ( 19 ) and pressure roller ( 21 ), through the thread guides ( 17 ) and the sliding piece ( 16 ), and then wound on the reels ( 7 ).
With the pressure arms up ( 20 ) and the spindles ( 5 ) stopped, the feeding rollers ( 18 ), the ring rail ( 15 ) and the thread guide ( 17 ) are started by means of the feeding system start switch ( 51 ). Further, the motors driving the spindles are started in sequence by means of individual switches.
The twist index is given by the control unit or microprocessor ( 29 ) to the frequency variator in each motor based on turning speed of each spindle provided by the encoder or motor pulse generator and by the turning speed of the feeding rollers, also provided by the pulse generator or encoder of the frequency variator of feeding rollers driving motor.
Simultaneously, the operation cycle is started, winding or folding the thread or welt on the reel central body ( 53 ) with upwards movement and when reaching the maximum reel height by the action of the ring rail sliding piece, the thread or welt starts folding next coat in downwards direction, in this case of smaller height since it is conditioned by the programmed dimension of high cone ( 48 ), and so on to configure a complete subcycle ( 45 ) with n coats ( 44 ) which will start the configuration of a new subcycle, with the same number of coats than the previous one, which in accordance with the low cone ( 47 ) dimension, will be of smaller height than the previous one, and so on, to the point in which, as a consequence of the programmed length to be folded on each reel, the reel will stop whereas the remaining spindles will continue the process without being required to stop. Once the filled reel is replaced with an empty reel, the individual starting switch ( 52 ) is turned on to initiate the reel operation, starting a new folding process.
It is possible to introduce changes in shape, arrangement and constitution in the assembly and its components, as long as those alterations do not affect substantially the characteristics of the invention as claimed below.
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Modular machine for spinning and doubling with individual transmission elementos for spindles with continuous, individual, conical or double conical folding system, comprising a frame formed by two metal cabinets connected to each other by means of a central body; the machine further comprises
a series of mobile elements; the spindles with their respective driving system, the ring rail on which the travellers turn around, the yarn guide, the feeding system and the control panel, said machine being capable of producing bobbins wound by the conical or double conical continuous, individual, winding system. Said machine can be used for spinning and doubling yarn, cord or similar product in a continuous endless process.
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TECHNICAL FIELD
This invention relates to appliances used in the stabilization and fusion of spinal vertebrae during and after spine surgery, and more specifically, relates to systems and methods for using a fusion plate for stabilizing vertebrae as part of a corpectomy or discectomy procedure to allow bone growth to occur.
BACKGROUND
Fusion plates have been in use as appliances for immobilizing and fusing adjacent spinal vertebrae following a discectomy (spinal disc removal) or for immobilizing the area surrounding a corpectomy (removal of an entire vertebral body). When these procedures are performed, a gap in the spine remains from the removed disc or vertebral body; this gap typically being closed by inserting a bone graft, usually from a cadaver. The adjacent vertebrae surrounding the discectomy or corpectomy site are then immobilized by attaching a fusion plate, usually on the anterior side of the spine, so that the vertebrae fuse to the bone graft, forming an entire fused section of the spine. Such fusing of vertebrae to the bone graft requires that the vertebrae remain immobile. Any movement during the healing process can cause a lack of fusion to occur, essentially forming a false joint in the spine at the discetomy or corpectomy site.
Presently, in performing a discectomy or corpectomy, a device called a “distractor” is used to spread the adjacent vertebrae so that the disc or vertebral body of interest can be removed. In use, a pair of distractor pins, which are essentially screws having a head for engaging with the distractor, are screwed into the vertebrae adjacent to the discectomy or corpectomy site. One pin is placed in the upper vertebra, and a second pin is placed in the lower vertebra, both vertebrae being directly adjacent to the discectomy or corpectomy site. The distractor tool is then coupled to the pins on the upper and lower vertebrae, above and below the site, and the vertebrae are then mechanically spread apart, for aiding in the removal of any remaining portion of the deteriorated disc or vertebral body, and also to create a gap for placing a bone graft. Once the bone graft is placed, the distractor is removed; next, the distractor pins are removed from the spine, and finally, a fusion plate is placed in a position for keeping the adjacent upper and lower vertebrae as well as the bone graft immobilized. The plate is screwed into the upper and lower vertebrae the goal of which is to provide sufficient immobility to cause fusion between the vertebrae and bone graft to occur. Examples of fusion plates presently existing in the art, which are used in the heretofore described manner, are those produced by EBI Biomet, Inc., Dupuy AcroMed, Inc., and Spinal Concepts, Inc, to name a few.
Two drawbacks with the present fusion plate methods and systems are: 1) the plate is often positioned off-center on the spine, during these procedures, due to the fact that there has not been a system in place to properly align the fusion plate on the spine; and 2) the above methods rely only on the natural compression of the spine (e.g. once the distractor is removed), to compress the vertebrae sufficiently against the bone graft, to allow fusion to begin. With regard to the first drawback, a fusion plate positioned off-center can result in aesthetic objections from a patient in whom a fusion plate has been implanted. This often occurs when a patient examines his spinal X-ray following surgery and the fusion plate is off-center, or crooked, leading the patient to surmise that the surgeon has performed a haphazard job. With regard to the second drawback, the failure to sufficiently compress the vertebra and bone graft together, prior to placing and anchoring the fusion plate, results in unnecessary space remaining between these components, and reduces the likelihood that fusion will occur (this can cause the “false jointing” problems noted above).
Therefore, a need exists for a fusion plate system and method which allows a section of spine to be compressed adequately following a corpectomy or discectomy, so that sufficient immobilization and spinal fusion can occur. Additionally, a need exists for a fusion plate system and method which allows a fusion plate to be centered properly upon a spine.
The foregoing reflects the state of the art of which the inventor is aware, and is tendered with a view toward discharging the inventors' acknowledged duty of candor, which may be pertinent to the patentability of the present invention. It is respectfully stipulated, however, that the foregoing discussion does not teach or render obvious, singly or when considered in combination, the inventor's claimed invention.
SUMMARY OF THE INVENTION
The invention overcomes the drawbacks of the prior art by providing a modified fusion plate system, and method for installing this system upon a patient's spine. This method and system allows a desired level of compression to be applied to the adjacent vertebrae surrounding the site of a corpectomy or discectomy, prior to, and during, the anchoring of the fusion plate. Furthermore, the inventive fusion plate system and method results in the fusion plate being properly centered upon a patient's spine, so that an aesthetically pleasing, as well as functional, surgical result is achieved.
The inventive system and method relies upon mechanically compressing the spine to draw vertebrae together until these vertebrae are in contact with a bone graft located in the gap left by a corpectomy or discectomy. Once the spine is compressed, the fusion plate is guided to a centered positioning upon the spine over the site of the corpectomy. Finally, the fusion plate is anchored upon the spine, while the spine is still undergoing mechanical compression. The reliance of this system and method upon mechanical compression of the spine while the fusion plate is anchored, is intended to reduce spaces between the bone graft and adjacent vertebrae at the site of a corpectomy or discectomy, as much as possible, so that spinal fusion has the greatest chance of occurring.
In the preferred embodiment, the inventive system uses a distractor device to not only distract (e.g. spread) vertebrae, in the manner presently used, but additionally, to mechanically compress vertebrae and any bone graft located there between. Furthermore, the addition of sizing graduations to the inventive distractor device, correlating to the sizes of different fusion plates, allows a properly sized fusion plate to be selected by the surgeon for a particular application, with minimal trial and error.
The inventive system and method uses distractor pins to properly guide the fusion plate to a centered positioning upon a patient's spine. Once guided onto the spine, the fusion plate is anchored with bone screws. The distractor pins are centered on the spine using anatomical landmarks such as the longis colli muscles or uncinate processes. The distractor pins are also designed for having a compressing force applied to them by the distractor device such that they do not bend or disengage from the distractor device upon compressing the spine to a desired level.
Accordingly, the following objects and advantages of the invention apply:
It is an object of this invention to provide a fusion plate system and method which results in improved fusion of spinal vertebrae following a corpectomy or discectomy.
It is another object of this invention to provide a fusion plate system and method which causes a fusion plate to be centered upon a patient's spine.
Further objects and advantages of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing preferred embodiments of the invention, without placing limitations thereon.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood by reference to the following drawings which are for illustrative purposes only:
FIG. 1 is a plan view of the C-4 and C-6 vertebrae with the C-5 vertebral body removed as in a corpectomy procedure and wherein the C-4 and C-6 vertebrae each have a centered distractor pin coupled thereto.
FIG. 2 is a plan view of the C-4 and C-6 vertebrae shown with a bone graft positioned in the gap left by the removal of the C-5 vertebral body, this view again showing centered distractor pins coupled to the C-4 and C-6 vertebrae.
FIG. 3A is a perspective view of a first preferred embodiment of the distractor pin of the inventive system, this embodiment having a slender head portion and a section that is hexagonal for mating with a surgical wrench.
FIG. 3B is a perspective view of a second preferred embodiment of the distractor pin of the inventive system, this embodiment having a groove located at the bottom end of the pin head portion, this groove for mating with the terminal end of a distractor device armature.
FIG. 3C is a perspective view of a third preferred embodiment of the distractor pin having a spring loaded, flexible portion.
FIG. 4 is a perspective view of a distractor device of the inventive system, this view showing the carriage body and associated armature traveling in an extended (distracted) direction.
FIG. 5 is a perspective view of the distractor device of FIG. 4, showing the opposite side of the distractor device shown in FIG. 4, with the carriage body and associated armature traveling in a compressed direction.
FIG. 6 is an end view of the carriage body of the distractor device.
FIG. 7 is a closeup side cutaway view of the carriage body element positioned on a section of the rack of the inventive distractor device showing a two-way toggling mechanism toggling in a position for distraction.
FIG. 8 is a closeup side cutaway view of the carriage body element positioned on a section of the rack of the inventive distractor device showing a two-way toggling mechanism toggling in a position for compression.
FIG. 9A is a closeup view of a distractor device armature and the bore of its terminal end portion showing a spring clamp coupling mechanism for coupling to the head portions of distractor pins of the type shown in FIG. 3 B.
FIG. 9B is a closeup cutaway view of the terminal end portion of the inventive distractor device showing the spring clamp coupling mechanism engaging the head portion of a distractor pin of the type shown in FIG. 3 B.
FIG. 10A is a closeup view of a section of the rack portion of the inventive distractor device having a measuring scale graduated in millimeters.
FIG. 10B is a closeup view of a section of the rack portion of the inventive distractor device having a measuring scale indicating an exemplary manufacturer's fusion plate model numbers.
FIG. 11A is a plan view of a fusion plate used for a discectomy procedure, having a cleft engagement means for snugly engaging the head of a distractor pin.
FIG. 11B is a perspective view of the plate shown in FIG. 11A showing the plate having a curvature for conforming to the shape of the anterior portion of a spine.
FIG. 11C is a plan view of the fusion plate shown in FIG. 11A showing the head portions of distractor pins snugly engaged within the cleft engagement means of the fusion plate.
FIG. 12A is a plan view of a fusion plate used for a corpectomy procedure.
FIG. 12B is a perspective view of another style of fusion plate used for a corpectomy procedure this view showing a curvature for conforming to the shape of the anterior portion of a spine.
FIG. 12C is a plan view of the fusion plate shown in FIG. 12B showing the head portions of distractor pins snugly engaged within the cleft portions of the plate.
FIG. 13 is a side view of the C-4 and C-6 vertebrae with the C-5 vertebral body removed and a gap located there between, as would occur in a corpectomy procedure. The distractor pins are aligned perpendicularly to the C-4 and C-6 vertebrae.
FIG. 14 is an elevated perspective view of the distractor device of FIG. 4 coupling to distractor pins in turn coupled to the C-4 and C-6 vertebrae and spreading these vertebrae apart. The C-5 vertebral body has been removed as in a corpectomy procedure and a bone graft has been placed in the gap left by the removal of the vertebral body. The spreading of the vertebrae here allows the vertebral body to be removed from the C-5 vertebrae and allows the bone graft to be placed.
FIG. 15 is an elevated perspective view of the distractor device of FIG. 4 coupled to distractor pins in turn coupled to the C-4 and C-6 vertebrae with a bone graft filling the gap left by the removal of the C-5 vertebral body as in a corpectomy procedure. Here the distractor device is being used to compress the C-4 and C-6 vertebrae against the bone graft.
FIG. 16 is an elevated perspective view of the distractor device of FIG. 4 coupled to distractor pins and compressing the C-4 and C-6 vertebrae against the bone graft while a fusion plate is positioned in a centered manner by distractor pins at the corpectomy site.
FIG. 17 is a closeup elevated perspective view of the terminal ends of the distractor device of FIG. 4 coupled to distractor pins and compressively holding the C-4 and C-6 vertebrae against the bone graft while a fusion plate is being anchored into place over the corpectomy site. Here a modified drill guide is used to apply the anchor screw to the fusion plate, the guide tube of drill guide being shown in cutaway with an anchor screw and screw driver placed therein. The terminal end of drill guide tube is shown seated in a chamfered region surrounding anchor holes
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a section of cervical spine 10 with a vertebral body (not shown) removed from a fifth cervical vertebrae (C-5) 12 as would result in a standard corpectomy procedure. While the cervical section of a human spine is shown here, this is for illustrative purposes only, as this invention could be used on other vertebral sections, such as the thoracic or lumbar sections of the spine. Additionally, while a human spine is shown in the drawings, the inventive system and method could be adapted to be used on sections of animal spines. In surgery the vertebral body of the (C-5) 12 vertebrae would have been removed in sections, being careful not to damage the dura covering (not shown) of the spinal cord, thereby leaving a gap 14 having the fourth (C-4) 16 and sixth (C-6) 18 cervical vertebrae located adjacent to gap 14 .
In a corpectomy procedure the gap 14 is filled with a bone graft 20 that is sized and shaped to fill gap 14 snugly as is shown in FIG. 2 . Prior to placing a bone graft into gap, the bottom surface 22 of the C-4 vertebrae and the top surface 24 of the C-6 vertebrae are usually scored by the surgeon to cause bleeding. This blood flow encourages the ossification process to occur between the cervical vertebrae 16 , 18 and the bone graft 20 placed in gap 14 , thereby causing fusion of these elements. If gravity is the only force acting on the spine to draw vertebrae 16 , 18 in contact with the bone graft 20 , it is possible for enough space to remain between the contacting surfaces of these elements, such that fusion will not occur at all. If fusion does not occur, this may necessitate a second surgery to correct the problem.
As shown in FIGS. 1 and 2, first and second distractor pins 26 are placed in the (C-4) 16 and (C-6) 18 vertebrae. In the inventive method and system, distractor pins 26 are used as leverage points for the application of a distractor device 30 for purposes of both distracting, or spreading the vertebrae, and additionally, for compressing the vertebrae. Due to the application of compressive force by the inventive method and distractor device, it is preferred that distractor pins 26 , be constructed from a non-bendable material such as titanium alloy.
FIG. 3A illustrates a distractor pin 26 of a preferred shape to accomplish the inventive system and method. Distractor pin 26 has a head portion 32 for coupling to a distractor device and a screw portion 34 for attaching to vertebrae. Preferably, head portion 32 is tapered 36 at its top with an overall slender cylindrical profile below the tapered top having a substantially uniform cylindrical diameter. A small hexagonal section 38 for engaging with a surgical wrench aids in driving the distractor pin into the vertebra. Alternately, the head portion 32 can also be designed to be a phillips head, for example, or designed with another means for driving screw portion 34 into vertebrae. The lower section 40 of head portion 32 is cylindrical with the rest of the head portion for engaging with the fusion plate 42 in a manner described further below.
FIG. 3B illustrates a second embodiment of distractor pin 26 with head portion 32 having a groove 44 located above lower section 40 . This groove 44 mates with a spring clamp 106 located in the bore 104 of the armature 50 A, 50 B of distractor device 30 to form a coupling mechanism as further described below.
FIG. 3C illustrates a third embodiment of distractor pin 26 having a spring loaded, flexible top 52 . The flexible top allows a surgeon to bend the top 52 slightly into the bore 104 of the armature 50 A, 50 B of the distractor device 30 , thus serving as a bore-guide. Flexible top 52 is especially useful in the bloody conditions of surgery where guiding the distractor armature 50 A, 50 B onto the head portion 32 of the distractor pin 26 is often done by feel. Distractor pins 26 are preferably approximately 12-14 mm long, with the screw portion 34 comprising the majority of the length of the distractor pin in relation to the head portion 32 . The screw portion 34 can be altered in length to conform to a range of patient's bone depth and density. For example, an osteoporotic patient may require a screw portion 34 longer than normal to allow additional purchase of the distractor pin 26 in the deteriorating bone.
Referring again to FIGS. 1 and 2, the step in the inventive method of centering distractor pins 26 can be examined. The method described here for centering distractor pins 26 on the (C-4) and (C-6) 16 , 18 vertebrae shown here would apply to other vertebrae located at other sections of the spine as well. The preferred method for accomplishing this step involves choosing a bilaterally symmetrical anatomical landmark such as the longis colli muscles (not shown), or the uncinate processes 54 of the vertebrae and using these landmarks for centering the distractor pins 26 . These landmarks are typically equidistant from the center of the cervical vertebra, and hence, the surgeon needs only to confirm the location of the equidistant center (demonstrated hereby arrows 130 ) and attach a distractor pin 26 to the vertebrae at that location, as shown in FIGS. 1 and 2.
Upon placing the distractor pins 26 in the manner heretofore described, a distractor device 30 , the preferred embodiment of which is shown in FIGS. 4 and 5 is coupled to distractor pins 26 . As shown, distractor device 30 is comprised of a carriage body 56 , a first armature 50 A coupled to carriage body 56 , a rack 60 for allowing the carriage body 56 a range of motion and a second armature 50 B coupled at an end of the rack 60 .
Referring also to FIGS. 6 and 7 carriage body 56 defines a chamber 64 along its length l. Chamber 64 has first and second openings 66 , 68 at an engagement end 70 and the opposite end 72 respectively, and openings 66 , 68 are in communication with the chamber 64 . The body 56 also defines a gear bore 74 at a location along length l, the gear bore 74 being in communication with chamber 64 . Gear bore 74 has an axis 76 which is perpendicular to length l of chamber. Gear bore 74 is preferably defined through carriage body 56 from the first side 78 to the opposite side 80 of the body 56 .
Referring again to FIGS. 4 and 5 and still to FIGS. 6 and 7, rack 60 is slidably disposed through first opening 66 and within the chamber 64 . Rack 60 has a first end 82 for engaging with first opening 66 and a second end 84 having a second armature 50 B coupled thereto. Rack 60 is slidable between a number of extended and compressed positions. FIG. 4 shows device 30 having rack 60 extended while FIG. 5 shows device 30 with rack being compressed to draw armatures 50 A, 50 B together. Rack 60 moves between extended and compressed positionings by engaging with gear 86 in gear bore 74 , using a number of spaced apart teeth 88 located on rack 60 .
Referring still to FIG. 7 and now to FIG. 8 the distractor device 30 also includes a two-way toggle switch 90 located atop carriage body 56 , toggle switch for allowing first armature 50 A coupled to carriage body 56 to alternately travel closer to, or away from, second armature 50 B. Carriage body 56 and its associated armature 50 A when traveling further from second armature 50 B causes distraction, or spreading of the vertebrae. Alternatively travel of carriage body 56 closer to second armature 50 B causes compression of vertebrae. Depending on the direction of travel desired, toggle switch 90 is switched so that the engaging member 92 located at each end of toggle switch arm 94 engages the gear teeth 88 of rack 60 . FIG. 7 shows the actuation position of toggle switch for distraction, while FIG. 8 shows the proper actuation position of toggle switch for compression. Upon switching toggle switch to a desired direction, engaging member is biased against gear teeth 88 by a spring (not shown), so that as handle 58 is turned, engaging member 92 is dragged over gear teeth 88 and locks in the valley of gear teeth. Upon locking, engaging member 92 prevents carriage body 56 from traveling in the opposite undesired direction, from which toggle switch 90 has been actuated.
Referring now to FIGS. 9A and 9B and still to the previous figures, the armatures 50 A, 50 B of distractor device 30 can be examined. First armature 50 A coupled to carriage body 56 is comprised of a first section 98 extending substantially perpendicularly outward from carriage body 56 and a second section 100 bent at an obtuse angle in relation to first section. Second armature 50 B is comprised of two similar sections 98 , 100 as first armature 50 A, except that second armature is stationarilly engaged to the end 84 of rack. FIG. 9A is a closeup of the terminal end 102 of either first or second armature 50 A, 50 B showing a bore 104 axially disposed within second section 100 of armature, the bore preferably including a coupling mechanism comprised of a spring clamp 106 for receiving and releasably holding the head portion 32 of a distractor pin 26 therein. Spring clamp 106 is preferably horseshoe-shaped with the semi-circular portion 108 having a slightly smaller diameter than the head portion of distractor pin 26 of the type shown in FIG. 3 B. The ends 110 of the horseshoe shape of spring clamp 106 are flexibly anchored to the body of terminal end 102 . The top 36 of distractor pin 26 is preferably tapered, as previously discussed, to easily slide spring clamp 106 over and onto the head portion 32 . As shown in FIG. 9B, upon positioning around head portion 32 , spring wire expands into space 121 inside of bore 104 and then compresses upon reaching groove 44 of distractor pin 26 . Once inside groove 44 , spring clamp 106 prevents distractor device 30 from migrating upward and slipping off of distractor pins 26 while vertebrae are being compressed. Spring clamp 106 can be removed from distractor pins 26 by applying gentle upward pressure on armatures 50 A, 50 B until device 30 disengages from distractor pin 26 .
Referring now to FIGS. 10A and 10B distractor device 30 includes a measuring scale 114 located upon rack 60 which allows a surgeon to select a properly sized fusion plate 42 for attachment at the site of a corpectomy or discectomy. Measuring scale 114 corresponds to a distance between the terminal ends 102 of armatures 50 A, 50 B, this distance corresponding to a preferred fusion plate size which will most likely fit over the site of a corpectomy or discectomy. Measuring scale 114 may have standard indicia 116 , such as millimeters or inches as shown in FIG. 10A, or else correspond to a particular sizing convention associated with a particular manufacturer for the plurality of fusion plates it produces, as shown in FIG. 10 B. For example a manufacturer may designate a plate as a “No. 1 plate” a “No. 2 plate” etc., to designate different sizes. Measuring scale 114 ensures that a properly fitted plate 42 will be placed by the surgeon with minimal trial and error.
FIGS. 11A-C and 12 A-C illustrate exemplary fusion plates 42 which comprise the inventive system and method. Fusion plates 42 are preferably surgical quality metal, such as titanium alloy, but composite materials which are not rejected by the immune response of the human body could also be used. Additionally, fusion plates may be comprised of a synthetic absorbable material which dissolves over time. Fusion plates 42 shown here, are for cervical applications and are fashioned to be placed upon the anterior portion of the cervical spine 10 . In FIGS. 11A-C fusion plate 42 is shorter and designed for use at the site of a discectomy. In FIGS. 12A-C fusion plate 42 is elongate for purposes of spanning the site of a corpectomy. The size of a bone graft required to fill in the site of a corpectomy is greater than the size of a bone graft required to fill in a discectomy, hence the differences in the length of fusion plates adapted to each separate procedure.
Fusion plate 42 has an inner surface 118 and an outer surface 120 , inner surface for contacting the anterior portion of the cervical spine 10 . Inner surface 118 preferably has at least a slight curvature 122 along its longitudinal axis for conforming to a similar curvature of the section of spine to which the fusion plate 42 will attach. For cervical applications the inner surface 118 has a slight concave curvature 122 along its longitudinal axis of the plate 42 . The plate can be bent further by the surgeon if needed. The inventive system and method requires that fusion plate 42 engage distractor pins 26 for purposes of centering fusion plate 42 properly. As shown in FIGS. 11A-C and 12 A-C, cleft 124 at upper 126 and lower 128 edges located centrally along the longitudinal axis of fusion plate 42 has a width for engaging snugly with lower section 40 , of the distractor pin head portions 32 .
Referring again to FIGS. 1 and 2 and additionally to FIG. 13 the remainder of the inventive surgical method can be described. Prior to placing distractor pins 26 in the centered manner as previously described, a determination of bone depth and density must be performed. This can be accomplished by taking an intra-operative lateral spine x-ray. The bone depth and denisty of the vertebrae must be sufficient to anchor distractor pins 26 and bone screws.
Once the central location on the vertebrae is determined, the surgeon preferably positions distractor pins 26 using an alignment guide (not shown) of a type well known in the art to make sure that distractor pins are perpendicular upon the spine, as shown in FIG. 13 . Perpendicular placement of the distractor pins 26 , aids in properly engaging terminal ends 102 of the armatures 50 A, 50 B of distractor device 30 . Once aligned, distractor pins 26 are then driven into the vertebrae at the centered locations using a hexagonal surgical wrench (not shown), until the screw portion 34 of the distractor pins 26 are seated within the vertebra, at a sufficient depth for allowing compression by the distractor tool 30 to occur.
Next, as shown in FIG. 14, terminal ends 102 of distractor device 30 are attached to the heads 32 of distractor pins 26 . A coupling mechanism 106 of the type previously noted in FIGS. 9A and 9B engages and couples onto groove 44 of head portions 32 . The toggle switch 90 on the carriage body 56 is actuated for spreading the (C-4) and (C-6) vertebrae 16 , 18 and handle 58 is turned to spread these vertebrae in the direction 132 shown. Next, the vertebral body (not shown) of the C-5 vertebrae 12 is removed. The engaging member 92 locks distractor 30 in a spread position, at this point, in preparation for placing a bone graft 20 between the (C-4) and (C-6) vertebrae 16 , 18 . The bottom surface 22 of the (C-4) vertebrae and top surface 24 of the (C-6) vertebrae are cleaned and scored to promote blood flow. Next, a bone graft 20 of appropriate size and shape is placed in the gap 14 left by the removal of the (C-5) vertebral body.
Referring to FIGS. 15 and 16 the steps of placing the fusion plate 42 and compressing the vertebrae using the mechanical compression exerted by the distractor device 30 , are demonstrated. Distractor device 30 remains engaged upon the heads of distractor pins 26 , and toggle switch 90 is actuated to cause carriage body 56 to travel in the direction 134 resulting in compression. Handle 58 is turned in a direction so as to compress the spine 10 until the (C-4) and (C-6) vertebrae 16 , 18 contact the bone graft 20 . Engagement member 92 locks first armature 50 A at the desired level of compression and keeps it there, thereby maintaining compression upon the bone graft 20 by the adjacent vertebrae 16 , 18 . Once the desired level of compression is reached, the surgeon can then read the measuring scale 114 on the rack 60 of the distractor device 30 to determine the appropriately sized fusion plate 42 which should be used in a particular application. The cleft 124 located at each of the opposite ends 126 , 128 of fusion plate 42 allows the surgeon to engage a properly sized fusion plate 42 upon the distractor pins 26 without removing the distractor device 30 . The fusion plate engages lower section 40 of head portion with cleft 124 . The clefts are preferably centered along the longitudinal axis of the fusion plate. This engagement results in the fusion plate 42 being centered upon the spine 10 , at the area of the corpectomy. The maintenance of compression on the spine 10 , while the fusion plate 42 is being placed, ensures that a minimal amount of space exists between the bone graft 20 and its adjacent vertebrae 16 , 18 , thereby providing the best chance for fusion to occur.
As further shown in FIG. 17, once compressed, bone screws 136 are placed in anchor holes 138 using a drill guide 140 . Bone screws 136 may be comprised of titanium alloy, composite material or synthetic absorbable material. Anchor holes 138 are preferably placed exterior to the longitudinal axis 137 of the fusion plate 42 . However, as shown in FIG. 12A anchor holes 138 may also be placed on the longitudinal axis, as some surgeons prefer to anchor fusion plate directly in the bone graft 20 , as well as in the adjacent vertebrae 16 , 18 . Drill guides are commonly used in spinal surgery, however the drill guide 140 shown has a wider diameter guide tube 142 to allow for a drill bit to work therein to start a pilot hole in both the patient's vertebrae 16 , 18 and bone graft 20 . The wider diameter of guide tube 142 also allows enough space to drop a bone screw 136 down the guide tube 142 and drive it into the spine 10 with a screw driver 144 . Alternately, guide tube 142 can be used to hold bone screw 136 upright and start driving bone screw into spine 10 without first drilling a pilot hole. By using a drill guide 140 to guide bone screws 136 without using a pilot hole, bone screws are added in one step, and the frequent struggle to find a pilot hole in the middle of surgery is eliminated. Drill guide 140 is held steady during the addition of bone screws 136 by handle 145 . To further ensure the proper alignment of bone screws 136 , a furrowed region 146 surrounding anchor hole 138 allows the terminal end 148 of guide tube 142 to seat in an aligned manner upon fusion plate 42 . Additionally, anchor hole 138 includes chamfer 149 which allows bone screw 136 to seat flush with top surface 120 of fusion plate 42 . Anchor holes 138 may include locking washers (not shown) seated therein to prevent bone screws 136 from backing out.
Clefts 124 at each of the opposite ends 126 , 128 preferably do not protrude beyond anchor holes 138 located at each of ends 126 , 128 . Distractor pins 26 have been previously placed at a location on the vertebrae where bone density is adequate for strong implantation, to withstand the leveraging force on the distractor pins 26 due to compression. The region near the cleft 124 , on average, has a similar sufficient bone density for placement of the bone screws 136 . By positioning clefts 124 so that they do not protrude beyond anchor holes 138 , an increased likelihood that bone screws 136 will be inserted into a similar region of adequate bone density as the distractor pins 26 , occurs.
When the fusion plate 42 is fully anchored, the distractor device 30 and distractor pins 26 are removed from the patient's spine. When fusion plate 42 is anchored, bone graft 20 and its adjacent vertebrae 16 , 18 are immobilized in a contacting manner, thereby creating the best conditions for bone fusion to occur.
The foregoing detailed disclosure of the inventive system and method is considered as only illustrative of the preferred embodiment of, and not a limitation upon the scope of, the invention. Those skilled in the art will envision many other possible variations of the system and method for its use as disclosed herein that nevertheless fall within the scope of the following claims. And, alternative uses for this system and method may later be realized. Accordingly, the scope of the invention should be determined with reference to the appended claims, and not by the examples which have herein been given.
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The invention provides a fusion plate system, and method for installing this system upon a patient's spine. The system uses a distractor device which measures an appropriately sized fusion plate for a corpectomy or discectomy application. Once a properly sized fusion plate is selected, the distractor device compresses the vertebrae and any associated bone graft placed between the vertebrae, thereby assuring maximum contact between the vertebrae and bone graft at a corpectomy or discectomy location. Compression is maintained by the distractor device while the fusion plate is anchored upon the corpectomy or discectomy site. Furthermore, the inventive fusion plate system and method results in the fusion plate being properly centered upon a patient's spine, so that an aesthetically pleasing, as well as functional, surgical result is achieved.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to rotors for reluctance machines. The invention is particularly applicable to a reluctance machine designed to be run at high speed.
2. Description of Related Art
Among the inefficiencies that a reluctance machine designer may have to take into consideration are the so-called `windage losses`. These are the result of the machine rotor creating turbulence in the air as it spins in the stator. The problem of windage losses becomes more and more significant as the operational speed of the machine increases.
It is known to seek to reduce the windage losses associated with a stator by filling the spaces between stator poles.
It is also known to seek to reduce the windage losses associated with a rotor by filling the spaces between rotor poles. An example of this is disclosed in U.S. Pat. No. 5,053,666 (Kliman et al). In Kliman the fillers are keyed into the spaces between rotor poles by angularly projecting, and longitudinally extending projections in one of the rotor poles. The fillers mate with complementarily shaped recesses in the rotor poles. Thus, it is known to attempt to reduce windage losses in a switched reluctance machine rotor by the use of fillers between the rotor poles such that the rotor assembly defines a circular cross-section cylindrical arrangement.
As the working speed of a rotor for a switched reluctance machine increases, the centrifugal forces imposed on the fillers increase accordingly. Some recent developments in switched reluctance motors call for design speeds in excess of 30,000 rpm (500 rev/sec). At such speeds the windage losses are excessive and the ability of known fillers to withstand the high centrifugal forces involved is considered to be inadequate. While such fillers may be secured so that they can withstand the centrifugal forces, they may still creep radially outwardly and upset the balance of the rotor.
In a modified form of rotor disclosed in Kliman, the laminations of the rotor poles are separate segments which are inserted in the spaces between fillers, arranged in a cage-like construction, and fixed to a rotor core. Separate non-magnetic support laminations replace some of the rotor laminations around the rotor core. These support laminations form a ring of intersticial connectors between the axially extending interpole fillers. According to Kliman, each separate rotor pole lamination has to be connected with the filler cage, e.g. by welding. The rotor has to be constructed in many parts and assembled around the filler cage which itself requires relatively elaborate assembly.
SUMMARY OF THE INVENTION
To address this and other disadvantages, it is an object of the present invention to provide a rotor for a reluctance machine that is more simple in construction and more efficient when running.
According to embodiment of the present invention there is provided a rotor for a reluctance machine comprising a rotor shaft, at least a pair of rotor members mounted on the shaft, each defining rotor poles and interpole regions therebetween, a filler in each interpole region and at least one insert also mounted on the rotor shaft, arranged between the rotor members, to which insert the fillers are secured.
The insert preferably has an integral cross-section and is in the form of a discate member mounted on a rotor shaft in common with the rotor members which are separated by the insert. In particular, it is preferable that the insert is circumferentially continuous and defines a radially outer surface which is coincident with the end faces of the rotor poles.
The filler may fill the interpole region. For example, it may be in the form of an injected material such as a resin or mouldable plastics. On the other hand, the filler may define an outer plate, extending between the end faces of adjacent rotor poles.
Preferably, one of the rotor poles and the filler is keyed into the other of the rotor poles and the filler.
The rotor may have an end cap mounted on each axial end of the rotor which is connected with the fillers. Again, the end caps preferably have an outer periphery which is in conformity with the radially outer surface of the pole faces and the interjacent fillers. For a particularly secure construction, it is preferable that at least one end cap and at least a part of at least one filler are of a unitary construction. Alternatively, one of the end cap and the fillers may be secured to the other.
The insert provides securement between the ends of the rotor to which the fillers can be fixed additionally by the use of end caps. The ends of the fillers are secured to the insert which is secured relative to the rotor member.
The insert should desirably have no substantial effect on the flux paths established in the rotor and the stator. The inventor has recognized that the lack of a significant axial component in the flux paths can be exploited to allow the rotor to be split into axially separated components providing a net benefit in the security with which the fillers are held in place.
Preferably, the insert is a non-metallic disc which provides the required centrifugal stiffness, being made of a ceramic material, for example, or a composite plastics material. However, it could be made of a non-magnetic material such as aluminium, although eddy currents would flow in a non-magnetic conductor when such a rotor is used.
While a single insert mounted midway along the axis of the rotor is preferable in some applications, embodiment of the invention also extend to the use of two or more inserts holding the filler radially and being positioned at spaced intervals along the rotor.
Embodiments of the invention have the benefit of anchoring fillers in a rotor particularly for use in high speed applications. While the flux carrying capacity of the rotor is compromised by the presence of the insert, the overall performance of the machine with the insert in place is enhanced because of the avoided windage losses, resulting in a net gain in efficiency without disturbing the radial integrity of the rotor, ie. the direction in which substantially all the flux flows.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention can be put into practice in various ways, some of which will now be described by way of example with reference to the accompanying drawings in which:
FIGS. 1A, B & C are a lateral cross-section, and first and second axial cross-sections taken along lines A--A and B--B, respectively, of an embodiment according to the invention;
FIG. 2 is a lateral cross-section of a switched reluctance machine embodiment according to the invention; and
FIGS. 3A, B & C are a lateral cross-section, and first and second axial cross-sections taken along lines C--C and D--D, respectively, of an embodiment according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIGS. 1A to C, a rotor assembly for a switched reluctance machine comprises a rotor 10 of conventional cross-section but comprising rotor members in the form of first and second stacks 12 and 14 of rotor laminations which are mounted on, and secured with respect to, a continuous rotor shaft 16. Typical securement methods include keying, clamping, an interference fit or the like as will be well-known to the skilled person. The laminations making up the stacks preferably are known in the art and preferably are made of electrical sheet steel of an appropriate grade, e.g. TRANSIL 315-35, as supplied by British Steel, Great Britain. As will be clear from FIG. 1C, the rotor 10 defines an inner core part 18 and four equi-angular spaced rotor poles 20. The axially adjacent stacks 12 and 14 in this embodiment are of equal length and are axially separated by an insert 22 in the form of a circular disc made of aluminium which is also mounted on and secured to the shaft 16. An end plate 24 is also mounted on the shaft at each end of the rotor 10. The cross-section of the insert and the end caps is circular and of a radial extent coincident with the faces of the poles 20 of the rotor.
The insert 22 and the end plates 24 are formed with blind arcuate recesses 26 extending axially in respective filler contact zones. A filler plate 28 made of ceramic having an arcuate axial section (shown in FIG. 1C) is arranged in each interpole region extending between the angularly adjacent flanks of neighboring rotor poles 20. Each filler plate 28 has an axially extending arcuate projection 30 formed at each end which is located in the corresponding recess 26 in the adjacent end plate 24 and the insert 22, respectively, the projections and recesses forming securing members of the rotor. The filler contact zones alternate circumferentially with rotor-pole contact zones, as can be envisioned with respect to e.g. FIG. 1B.
As will be seen in FIG. 1C, the cylindrical outer surface of the filler plates together with the radially outer pole faces of the rotor poles 20, define a smooth circular cross-section surface. The end plates 24 present a smooth outer surface at either end of the rotor.
At high speeds the central insert 22 serves to retain the fillers in place. While the machine is made reliably quieter running and less lossy, the insert does have some detrimental effect on the flux carrying capacity of the rotor because of the volume of rotor given up to the insert. The iron losses in the rotor increase as the material of the rotor is removed. However, it has been found that the insert according to the invention provides a net benefit by allowing windage losses to be reduced at high speed and simply and reliably secures the fillers in position. Previous techniques for securing the fillers in place have relied on connecting them only at both ends or by holding solid fillers in place in the interpole region.
FIG. 2 shows an alternative form of the invention in a reluctance machine construction comprising a stator 32, defining stator poles 34, in which the rotor 10 is arranged to rotate. The stator poles 34 carry phase windings 36 as is conventional in the art. In this embodiment the rotor is provided with a solid filler 38 in each interpole area. An insert (not shown) is present, similar to that in FIGS. 1A to C, having blind arcuate recesses receiving projections on the filler as before. The solid fillers 38 of FIG. 2 may be either pre-formed or molded to the rotor so that the projections engaging the recesses 26 are formed in the molding process. While the solid filler is shown taking up all of the interpole region, it is equally possible for it to leave voids at, for example, the root of the region between the poles. A suitable material for the molding solid filler is an injection molded plastic loaded with a suitable strengthening material, such as Nylon 66.
FIGS. 3A to 3C show a further alternative form of the invention in which rotor members 40 have rotor poles 42 formed with axially extending keyways 44 on either flank. A filler plate 46 which is similar to that shown in FIGS. 1A to C has an axially extending lug 48 on each side which is arranged to engage a respective keyway 44 on either side of the interpole area between adjacent poles 42.
In this embodiment an insert 52 is also arranged midway between the rotor lamination stacks on the shaft 16. The insert 52 has an arcuate array of circular blind recesses 54 in place of the equiangularly spaced arcuate recesses of FIGS. 1A to C. The radially inner part of the insert 52 defines a pair of axially opposite recesses 60 in the form of annuli. The rotor laminations are formed with complementarily shaped axial ends 62 that are received in the recesses. This engagement of the insert 52 by a further part of the rotor benefits the security of the fitting of the rotor members on the shaft. The filler plates 46 are integrally molded as part of one of a pair of end caps 58. Each end cap 58 is mounted on the shaft 16 so that the lugs 48 run along the keyways 44, and the end caps 58 mate against a respective axial end of the rotor portions and the distal ends of the filler plates 46 engage the recesses 54.
It will be appreciated that the insert and the fillers could equally well be constructed as an integral member such that the end plates were required to be secured in mating relationship with them. Also, the fillers could be continuous having a keyed relationship with the insert by which they are secured radially and yet able to be slid axially into place.
The presence of the insert reduces the flux carrying capacity of the rotor. Nevertheless, embodiments of the invention allow the use of fillers at high speed by improving the manner in which they are retained in place. The insert provides an attachment point between the rotor ends without disturbing the cross-sectional integrity of the rotor laminations. The rotor fillers are reliably held in place while the overall efficiency of the machine is improved at high speeds because of the reduction in windage losses.
Embodiments of the invention is applicable to rotors designed to run at different speeds. Nevertheless, it of particular advantage at very high speeds. Thus, particular care should be exercised in choosing the material for the fillers and the inserts. It is preferable that the filler should not increase the rotor mass significantly. Therefore, the density of the filler material may need to be taken into consideration. The fillers have to be magnetically transparent so that they have little or no appreciable effect on the flux path between the stator poles and the rotor poles.
A metal filler could be used, but it is necessary for it to insulated at least at one end to eliminate the possibility of losses due to a closed electrical circuit being formed around a rotor pole. A suitable metal filler is aluminium as it is non-magnetic. A particularly preferred material for the filler is a ceramic as it is both non-magnetic and non-conducting. A further alternative is an epoxy resin type molded filler particulary for solid filler applications.
Thus, while the present invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and description herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is intended to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined in the appended claims.
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A rotor for a reluctance machine comprises a rotor made up of a stack of laminations defining a cross-sectionally integral rotor profile consisting of rotor poles arranged about a rotor core. A non-magnetic insert is arranged axially along the stack of laminations and a filler spans the interpole region between rotor poles. The filler is attached at either end of the rotor to an end cap and is secured to the insert intermediate the rotor ends. The insert provides a means of securement for the filler to provide stability at high speed.
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TECHNICAL FIELD
The present invention generally relates to a system for heating a charge of water or other liquid and is particularly applicable to machines and systems heating water for infusion purposes, e.g., for brewing coffee or tea, and subsequently maintaining the heated charge or infused liquid at an elevated temperature, e.g., at a "warm" or "hot", drinking temperature. The invention is particularly useful in coffee makers or other apparatus for heating water for infusion purposes in which a cold or unheated water charge is contained in a reservoir and is heated and transferred to a second chamber (hot drink vessel) in which it is maintained at the elevated temperature. In addition, the present invention is particularly useful in systems utilizing a single heating means, such as a flow through heating unit, for heating water, or other liquid from the reservoir chamber, pumping the heated liquid to the second chamber, and maintaining the liquid in the second chamber at an elevated temperature while awaiting use. However, the concepts may be utilized in systems utilizing other types of heating units, or other arrangements.
Various systems are known for heating a charge of water contained in a reservoir chamber and effecting a transfer of heated water to a second chamber in which the liquid is maintained at an elevated temperature. Such systems are in common use to provide hot water for infusing coffee or tea. In such systems hot water flows through a coffee or tea infusion chamber during its transfer to the second chamber which may be a decanter or carafe. In known coffee makers, a flow-through heating and pumping unit is displaced from the reservoir, most often at or below the level of the bottom of the reservoir, and an outlet from the bottom of the reservoir is connected to the heating and pumping unit. The water flows, by gravity and siphon effect, through a check valve from the reservoir to the flow-through heating and pumping unit. In such a system, the water is heated as it flows through the heater and hot water is delivered from the outlet of the heater to a riser system through which it is pumped upwardly and discharged above the top of the infusion chamber or coffee basket. The pumping action is usually achieved by the cooperation of the check valve located below the cold water reservoir and the heating of the water in the heater unit. As the water heats up, it expands and vapor is generated. The unidirectional check valve keeps the hot water from flowing back into the cold water reservoir and thus the water is forced to flow into the infusion basket and then into the hot drink vessel.
In known systems, the heating unit operates continuously at full power while heating the water and transferring it. When the water has been substantially all transferred, the heat input to the heating unit is no longer dissipated by the water and the temperature of the heating unit rises causing a thermostat to cut off the power and to thereafter operate in an on/off duty cycle mode, to maintain the temperature of the heating means within a predetermined range for keeping the liquid warm. In some systems, once the water has been transferred and the thermostat has been activated, power is applied to the heating unit through resistors to lower the temperature of the heating unit. This method requires high wattage resistors and is wasteful of energy. In systems where the cold water is heated by a heater unit separate from the one for the warming operation, contacts for the main heater may be thermally held open during the warming operation so as to keep said heater deenergized during said operation.
One of the problems encountered in known systems when operating in the warming mode is the difficulty in achieving the appropriate level of heat energy to maintain the liquid in the vessel at the desired drinking temperature. This is achieved by the insertion of energy dissipating resistors in the heating circuits or, to avoid the use of resistors, by cycling on/off full power to the heating unit. In such systems, when the liquid in the vessel being maintained at an elevated temperature has been substantially dispensed therefrom, the temperature of the heating means builds to approximate the thermostat cut out temperature. While the cut out temperature may be set so that there is no fire hazard, a substantially dry vessel, such as a carafe in a coffee maker, may be ruined because of the drying and "burning on" of the residue. Furthermore, the on/off cycling will continue until the apparatus is turned off. If the equipment is left unattended, this condition may persist for long periods and irreparably damage the vessel. This condition is hard for the manufacturer to control because of habits of various users including that of using a non-original replacement vessel which may have different heat transmitting characteristics from the original.
The present invention improves the operation of the heating cycle and also eliminates the problem encountered in the warming phase by allowing the user to control the temperature of the heating unit and thus the temperature of the liquid in the vessel and also by automatically turning off the apparatus should an empty vessel be left on the heating unit.
In known types of water heating apparatus, overheat conditions may occur if the vessel is empty or the control thermostat or other portions of the system have failed. To avoid dangerous conditions and alleviate fire danger, various thermostat arrangements have been provided to cut off power under various overheat conditions. This requires additional thermostats and adds to cost and complexity. The present invention improves the control of excessive temperature by monitoring the heating unit temperature at all times and taking the appropriate action without relying on additional thermostats which add cost and complexity and reduce reliability. The present invention eliminates the use of thermostats altogether and monitors temperature by temperature sensing means which, in cooperation with ancillary logic, control the apparatus during the brewing and warm cycle and turn off the apparatus when the temperature and conditions require it.
A further problem which arises with a water heating apparatus is limestone or other type deposits in the water passages of the heating unit. For example, in a flow through heater where a water carrying tube is heated to heat the water, the deposits will build up and interfere with the heat transfer from the heater, through the tube wall, to the water. This can cause the thermostat to cycle on and off, extend the brewing time and make the coffee taste bitter. In such cases, the water passages should be cleaned. In one known type of coffee maker, the water level in the cold water chamber is sensed and this is used in conjunction with a condition indicative of the heater temperature, which increases during the water heating operation as deposits increase, to provide a visual indication to the user that cleaning of the water tubes is needed.
Because of deposits, coffee makers and other similar water heating apparatus of the type described should be periodically cleaned with a cleaning solution to remove deposits, but this is often neglected by the user. The present invention includes features for reminding the user of the need for cleaning and for facilitating the cleaning of the apparatus.
SUMMARY OF THE INVENTION
One object of the invention is to eliminate the shortcoming of known devices, where the warming mode can only be obtained by first going through the brewing mode. The present invention in its preferred form allows the user to select the operating mode, i.e., AUTO, BREW, WARM only, or OFF. The preferred embodiment allows the mode selection to be accomplished by using a single push-button switch.
Another object of the invention is to allow the user to adjust the warming temperature level and thus obtain the temperature desired by the user for the beverage.
A further object of the invention is to have a constant monitoring of the operating temperature of the device and to make the appropriate logic decisions depending on the then active operating mode.
An additional object of the invention is to detect the build up of lime deposits in the apparatus and to warn the user of the need to clean the machine. In conjunction with this warning, the apparatus has an operating mode which allows unattended cleaning of the machine.
A further object of the invention is to maintain a constant temperature in the WARM mode while eliminating the use of power dissipating resistors, or duty cycle control.
Another object of the invention is to eliminate the use of thermostatic switches in the operation of the apparatus and thus improve performance.
The preferred form of the present invention provides a new and improved hot beverage infusion or water heating machine or apparatus and a control system therefore, which machine and control system preferably operates to provide a machine having multiple states with signals indicating the state of the machine and conditions within the states. The apparatus is such that it can be operated from one state to another by operator intervention regardless of the existing state of the machine, and during a BREW and WARM cycle is operated between states and conditions within states in response to certain information including temperature, or elapsed time period(s) in relationship to predetermined factors. The information is determined or gathered automatically by the control system, with said system being further responsive to user input during a cycle to effect a change from one state to another or to automatically start a cycle in response to a user set or controlled inputs such as automatic start in response to a preset timer.
The present invention in its preferred form provides an apparatus for heating a water or liquid for infusion purposes in which the apparatus and related control system have an AUTO state which can be manually initiated. The AUTO state allows the state of the apparatus to then be changed by a manual input or by external means such as a computer, modem or other signal generating means or an internal or external user settable clock. The apparatus further provides a BREW state for heating the liquid for infusion purposes, said state being capable of activation either by operator input means or by externally generated change of state means such as a clock/timer. The apparatus further provides a WARM state and an OFF state, said states being capable of activation either by operator input or by internally operated change of state means determined by operational conditions or predetermined user selectable elapsed times.
In the BREW state, the apparatus has heating means for heating the liquid to the appropriate infusion temperature and sensing means for monitoring the heating means temperature. The sensing means, in conjunction with related control means, is capable of monitoring several apparatus malfunctions (such as non-operational heating unit, temperature sensor, thermal fuses, power control semiconductor, control circuitry, etc.), detecting lime deposit build up in the apparatus requiring that the apparatus be cleaned, alerting the operator of change of state by indicator means and sequentially changing the state from BREW to WARM to OFF by control means. The temperature sensing means further controls power delivery means by applying, during the BREW cycle, essentially full alternating current line voltage to the heating means.
In the WARM cycle, the apparatus includes operator adjustable temperature control means for controlling the temperature of the beverage, power control means for activating power delivery means at the appropriate time during each half alternating current cycle to achieve the user selected temperature, operator selectable timing means for changing the state of the apparatus from the WARM to the OFF state and means for changing the state of the apparatus if the temperature of the heating means exceeds a preset high temperature threshold due to lack of liquid in the vessel or any other condition causing an elevated temperature.
The invention in its preferred from further provides visual indicator means indicating the active state and the deposit build up condition of the apparatus. The apparatus may further provide an audible signal via signal generating means, to alert the operator at each change of state.
A further preferred feature of the invention is that it provides vessel detection means which disable the delivery of power to the heating means if the vessel is removed from the apparatus at any stage of the operating cycle.
More particularly the present invention in its preferred form provides, among others, the following distinctive features:
1) Use of partial power, preferably without on/off thermostatic controls, without use of power dissipating elements, and without rectifier elements, during the WARM mode. In the preferred embodiment, the power level may be adjustable and the application of partial power to the heating means is accomplished by using a phase controlled triggerable semiconductor which, through power control means, is caused to conduct for the appropriate portion of each half A.C. current cycle to achieve the desired temperature. The temperature of the infused liquid thus remains essentially constant since partial power is applied at the same frequency of the A.C. line (typically 50 or 60 HZ) and power is not wasted in power dissipating elements.
2) Use of full power during the BREW cycle by triggering the phase controlled triggerable semiconductor a fraction of a millisecond after each time the A.C. voltage absolute value first exceeds zero volts. A further feature of the invention is the use of negative gate current to trigger the triggerable semiconductor.
3) Utilization of temperature sensing means operatively connected to the heating means to provide temperature information to the control system to cause all necessary state changes and further monitor malfunctions in the BREW state and overheat conditions in the WARM state. In the preferred embodiment, the temperature sensor is a thermistor which may be optimally connected to the heating means to optimally detect temperature variations of said heating means caused by lime deposit build up.
4) Monitoring of temperature during the BREW state to determine if the heating means exceed a specified temperature for a preset period of time due to lime deposits build up. If the condition occurs, clean indicator means are activated to alert the operator. Another feature is that the indicator means remains in its on state until another BREW cycle is initiated or the machine is unplugged from the A.C. source, but is not disabled when the machine reaches the OFF state.
5) Timer means activated when the BREW cycle is started, the timer means providing user selectable machine shut off times which will set the apparatus to the OFF state when the preset time has elapsed.
6) Temperature comparison means providing various temperature levels or ranges to which the control system responds: a first level or range is used by the control system when a BREW cycle is commenced to determine if the temperature sensing means is responding as it should, a higher second level or range is used in the course of the BREW state to determine if the system is in need of cleaning and to determine, if the BREW cycle has been completed, that partial power is to be turned on for the WARM state, and a third high level or range which, if exceeded or entered while in the BREW state, causes a switching from the BREW state to the WARM state and turns the heating power off until the temperature falls below the second level or range, at which time partial power is applied to achieve the desired temperature in the WARM state. The third high level additionally, depending on the state of the user selectable shut off means, can respond to conditioning signals established in the WARM state to shut down the system and preferably reset the control system to the OFF state if the temperature of the heating means again enters the high range.
7) User selectable states which allow operator to select any state without having to allow the normal completion of the prior state. This feature is particularly useful since it allows the operator to warm a drink without first going through the BREW cycle and also allows the user to fill the reservoir with an acidic cleaning fluid with the apparatus in the WARM mode or state. The heating and pumping action at the lower warming power level will thus take place at a much slower rate allowing the heated acid to fully dissolve the mineral deposits. In the preferred embodiment, once all of the acid has been pumped through the heater, the temperature will rise above the third high level and cause the machine to shut off automatically.
8) Vessel sensor means which detect the presence or absence of the beverage vessel from the apparatus and inhibits the application of power to the heating means.
Different apparatus utilizing subsets of the above features can be easily implemented by those skilled in the art.
DESCRIPTION OF THE DRAWINGS
The following description of a preferred embodiment of the invention is made with reference to the drawings which form a part of this specification for all subject matter discussed therein and in which:
FIG. 1 is a simplified front elevational view of a coffee brewer embodying the present invention;
FIG. 2 is a view of the heating unit of the brewer of FIG. 1 viewing the top of the heating unit from along line 2--2 in FIG. 1;
FIG. 3 is a cross-sectional view of the heater unit shown in FIG. 2 taken from along line 3--3;
FIG. 4 is an enlarged form of the control panel shown on the brewer in FIG. 1;
FIGS. 5A and 5B together form a functional block diagram of an embodiment of the invention;
FIG. 6 shows the A.C. waveform and the triac waveform during the BREW cycle;
FIG. 7 is a temperature graph for a typical complete operating cycle;
FIG. 8 shows the A.C. and triac waveform during the WARM cycle;
FIGS. 9A-9C show several embodiments of the vessel detector;
FIGS. 10A and 10B together form a logic flow diagram of the embodiment shown in block diagram form in FIGS. 5A and 5B.
FIGS. 11A-11J together are the electrical schematic for an embodiment of the device shown in FIGS. 5A and 5B.
DESCRIPTION OF PREFERRED EMBODIMENT
The preferred embodiment of the present invention as illustrated in FIG. 1 is shown in a coffee brewing machine 10, having a cold water reservoir 11, which is open to atmosphere, for receiving a charge of water to be heated and used in a coffee brewing operation, a beverage infusion basket 12, and a beverage vessel 13, providing a receiving container which is heated to maintain the warm beverage in a heated condition which is commonly and alternatively referred to as "hot" or "warm".
The machine includes heating means comprising a water heating unit 14 which, in the illustrated embodiment is a conventional U-shaped or horseshoe type water heater having a water tube 20 fixed to and heated by a calrod heater element 21 as shown in FIG. 3. The water tube 20 receives water by gravity from the cold water reservoir 11 through a water conduit 15, and a unidirectional check valve 17 is provided which allows water to flow downward by gravity but keeps heated water from being pumped back to the cold water reservoir. The heating element 21 is energized to heat the water for brewing purposes. A temperature sensing means 27 is on the water tube 20. Once the water has reached a sufficiently high temperature, the associated vapor of the water will pump the charge up through water conduit 18 into the infusion basket 12 where the heated water will infuse the coffee charge and the coffee (or other infused drink) will flow by gravity into the vessel 13, where the coffee is to be maintained at an appropriate drinking temperature. Once the hot water has been pumped into the infusion basket, another cold charge of water will flow from reservoir 11 into the heater unit 14 and the cycle will repeat until all of the cold water charge has been heated and pumped to the beverage infusion basket.
Referring to FIG. 4, the machine has a control system comprising a panel 22 including a momentary push button switch 23 for starting and selectively establishing various machine states, preferably a digital clock 24 settable by the user to start the machine at a selected time of a 24 hour day, an optional mode select switch 26 to select auto or manual operation, and a selector switch 25 for selecting the automatic shut-off time period that begins with the start of the brewing operation. A mode switch could be provided to selectively choose a manual mode, in which the heating cycle can only be started by the momentary push button switch 23, or to choose an auto mode to enable the control system to respond to a signal from the user set time clock 24 as well as the push button switch 23 or an external input such as a modem, etc. The panel includes indicator lights 29 for indicating various states and conditions of the machine as described hereafter and user controls for the machine, such as operator adjustable temperature control 28 for the WARM mode.
A schematic block diagram of an illustrative embodiment of the control system of applicant's invention is shown in FIGS. 5A and B. An A.C. source 124 provides power to a Power Supply 123. The Power Supply, through the use of a capacitor, rectifiers and voltage regulators provides an appropriate voltage, typically 5 V to power all of the logic units contained in the apparatus and eliminates the need for a power supply transformer. This low voltage floats on the neutral lead of the A.C. line and allows the triac (described below) to be driven directly.
The power supply also provides full line voltage through connection 130 to the Power Control Unit 119. The Power Control Unit is a semiconductor, such as a triac, which can be turned on and off at every A.C. cycle, to provide full or partial power to the Heating Unit 118 through the connection 131. The connections of the Power Supply to the other blocks have been omitted for the sake of clarity. When power is applied to the unit and the voltage at the Power Supply reaches a predetermined voltage V greater than V preset, a reset pulse is generated by the Power-up Reset Circuitry (PWR-UP RESET) 104. The Power-up Reset Circuitry 104 resets all of the state control flip-flops in State Controller 101 (described hereinafter) to the system OFF condition regardless of past status; tests the System Clock Oscillator Divider 103 and the Beeper Unit 102. If the self test does not detect any malfunctions with the master oscillator and clock divider stages, the Power-up Reset Circuitry 104 is reset by the System Clock 103, leaving the State Controller 101 in the OFF state and ready to receive further inputs to effect state changes.
State Controller 101 through functional connection 134 activates the Indicator Lights Drive 106 which in turn activates Indicator Lights 107 through 111 according to the state of the machine. When power is applied and the machine is reset, all of the indicator lights are in the OFF condition.
Once power has been applied to the system, the apparatus is ready to commence operations and is in the OFF or A state. The only input which can change the state of the machine at this time is PB (push button) 125 (described below) corresponding to the Select Switch 23 of FIG. 4. If PB is activated by being momentarily pressed, the corresponding input will cause the State Controller 101 to change to the AUTO or B state or to the BREW or C state depending on the condition of the Mode Select Input 127. If the Mode Select Input is open (manual operation), the State Controller 101 will change to the BREW or "C" state and the brewing cycle will commence. If the Mode Select Input is closed (auto operation), then State Controller 101 will change its state to AUTO. Once in the AUTO or B state, a further state change can occur either by temporarily closing PB switch 125 or automatically by sending a negative pulse to "Auto Start" control terminal 126. The source of the Auto Start mode may be a display clock 105 settable by the user and incorporated in the apparatus, an external telephone modem, a computer output or other external or remote input source implemented by the user. If optional switch ("Mode Select") 127 is open, the apparatus can only be operated manually. If switch 127 is closed, the apparatus can either be operated manually or through the auto start mode. In the description of the embodiment, it is assumed that switch 127 is closed. The operation with switch 127 open is a subset of the operation with switch 127 closed.
Once either inputs 125 or 126 have been activated, the State Controller circuitry 101 will activate, through output 132, Beeper Unit 102. The beeper unit is receiving a medium frequency signal (approximately 4 KHZ from System Clock 103) for approximately one second, thus informing the operator of a change of state. The beeper unit is similarly activated during all state changes. The audible signal could obviously be eliminated in other embodiments without loss of basic performance.
State Controller 101, which is composed of a series of flip-flops and associated gating circuitry, sends a control signal through connection 134 to the Indicator Lights drive circuitry 106 and the Auto light 107 is activated. At this point, the apparatus is ready for operation but needs an additional instruction input, either through the manual PB input 125 or through the Auto Start terminal 126 to initiate the brewing process. The present embodiment uses a digital Display Clock 105 to activate the Auto Start input at a specified time. Clearly other interface controls could be implemented by the user to activate the apparatus at the desired time or when predetermined conditions set by the user are met. If either PB control 125 is depressed or Auto Start terminal 126 receives a low signal, the State Controller 101 changes its state to the BREW or "C" state and activates the following functions:
1) The Beeper Unit 102 is activated for approximately one second to alert the user of the change in state.
2) The State Controller flip-flops change of state cause the Indicator Lights Drive circuitry 106 to turn on the ON Light 108 and the Brew Light 110.
3) The State Controller generates a D.C. signal in the high state on line 145 which enables Power Controller Unit 119. In the BREW mode the State Controller 101 also delivers a voltage state through line 135 to the Power Level Selector circuitry 122.
The function of the Power Level Selector circuitry 122 is to control whether the Power Control Unit is on essentially for the full A.C. cycle, as in the case of the BREW mode, or for only a portion of the A.C. cycle, as in the WARM mode.
The Power Control Unit is a semiconductor (i.e., triac) which can be fully turned on every half A.C. cycle of the A.C. line voltage. In the BREW mode, once it has been enabled, the power control unit is fully turned on each half A.C. cycle, approximately 600 82 s after the line voltage has crossed a zero voltage, by a negative pulse generated by the Trigger circuit 120. In the BREW mode the Zero Crossing detector 143 detects the change in sign of the A.C. voltage V L1 of FIG. 6 and activates the Trigger Delay circuit 144 which after approximately 600 μs activates the Trigger Circuit whose output I GT of FIG. 6 fires the Power Control unit. This represents the high power operation of the apparatus. The output of circuit 120 is shown in FIG. 6 as I GT . The line voltage is also shown in FIG. 6 as V L1 with V TRC representing the voltage across the Power Control Unit 119. When the Power Controller is fully on, the full line voltage is applied across Heating Unit element 118. When power is turned on to the Heating Unit 118, the Temperature Sensor Timer 113 is also activated by an input signal on line 136 from the State Controller. The Sensor Timer (a counter fed by the System Clock 103) counts for approximately one minute unless it is reset by an output T TAT 137 from Temperature Comparator 112 as described below.
As power is applied to the Heating Unit 118, the Temperature Sensor 114 (i.e., a thermistor) provides a signal on line 139 to the Temperature Comparator 112. The Temperature Comparator has three outputs labeled T TAT on line 137, T LO on line 140 and T HI on line 141. These outputs are activated whenever the temperature of the heating unit exceed the preestablished reference temperature for these three outputs. These temperatures have been chosen to be approximately 90° C. for T TAT , 150° C. for T LO and 170° C. for T HI . Other levels could be chosen to suit particular heaters, uses or liquids.
If T (temperature of heating unit) is not greater than T TAT before the Temperature Sensor Timer 113 completes its counting cycle, no output will occur at the T TAT output of Temperature Comparator 112 and the Temperature Sensor Timer 113 will generate a pulse on line 142 which will reset the State Controller to the OFF or A state, turn off all indicator lights and turn off all power to the heating unit. The operation of the apparatus is thus interrupted. This condition can occur for several reasons and the interruption of the cycle provides safe operation. The temperature of the heating unit may not reach the prescribed 90° C. within the allowed time for the following reasons:
1) the Heating Unit is open or defective and no heat is generated;
2) the thermistor is non-operational;
3) a thermal fuse is open;
4) the Power Control Unit is non-operational or
5) the Vessel Detector 128 is open (no receiving carafe).
Under any of these conditions, the BREW cycle should be discontinued.
If the temperature of the Heating Unit exceeds 90° C. before the Temperature Sensor Timer times out, then the Temperature Comparator will generate a signal T TAT on line 137 which will reset the timer and allow the brewing process to continue.
The temperature profile of the Heating Unit is shown in FIG. 7. The vertical axis represents temperatures of the Heating Unit while the horizontal axis represents time. The various temperature profiles contained within the BREW time on the horizontal axis are possible temperatures achieved by the heating element during a typical BREW cycle. The various dotted temperature profiles labeled "TAT SHUT-OFF" represent possible abnormal conditions where the temperature of the Heating Unit does not increase with sufficient rapidity because of the occurence of one or more of the malfunctions or conditions listed above. If T is less than T TAT (T<T TAT ) after the Temperature Sensor Timer 113 has completed its timing cycle, the Temperature Sensor Timer 113 will reset the State Controller 101 to the OFF or "A" state via line 142. Under normal operating conditions, T will exceed T TAT before timer 113 has gone through its counting cycle, but will remain below T LO until the end of the BREW cycle. During this period all of the fluid will be discharged from the reservoir into the vessel through the infusion basket, after having been heated by the Heating Unit.
Once all of the fluid has run through the Heating Unit, the temperature of the Heating Unit will continue to rise since it is no longer cooled by the fluid. The Temperature Sensor 114 will eventually detect a temperature higher than T HI and the Temperature Comparator 112 will have an output T HI on line 141 which will change the state of the State Controller 101. This change of state disables the Power Controller 119 so that no further power is applied to the Heating Unit 118. The State Controller 101 will also activate, through Indicator Lights Drive 106, the Warm Light 111. The apparatus is now in the WARM or D state. Once this state has been achieved, the State Controller also switches the Power Level Selector 122 to enable Phase Controller 121. The phase of the Phase Controller 121 is adjustable through Temperature Adjustment means 115 which is adjustable by the user.
During the transition from BREW to WARM, the Power Controller 119 has been disabled and thus the temperature monitored by the Temperature Sensor 114 starts decreasing as shown by the temperature profile in the PWR OFF time period of FIG. 7. When the Heating Unit temperature decreases to T LO the Temperature Comparator will have an output at the T LO terminal 140. This output causes State Controller 101 to enable once more the Power Controller 119. At this stage, power is applied for a portion of the line cycle.
As shown in FIG. 8, the Phase Controller 121 will delay the triggering of the Power Controller 119 until a later time (t WARM ) of the power half cycle. The actual trigger time can be adjusted by Temperature Adjustment 115 and thus the total amount of power delivered to t the Heating Unit is reduced to achieve the appropriate temperature level of the hot beverage during the WARM state. The dashed portion of the A.C. cycle in FIG. 8 represents the portion of A.C. line voltage applied to the Heating Unit 118 during the Warm cycle. "t WARM " may be advanced or delayed to control the temperature of the drink in the vessel.
If T, for lack of liquid in the vessel or other reason again increases above T HI , the second T HI output of the Temperature Comparator 112 will cause one of two events to occur. If the Thermal Shut-off input 147 is in a high state then the output T HI 141 will change the state of the State Controller from WARM to OFF and the apparatus is turned off. All indicator lights will also be turned off with the exception of the Clean Light 109 if it had been activated during the Brew cycle.
If the Thermal Shut-Off input was set low, then the State Controller 101 stays in the WARM state but via line 145 disables Power Control unit 119, turning power off to the Heating Unit 118 until the temperature falls below T LO at which time heating is reactivated and the cycle repeats until the WARM state ends.
Thus the apparatus may be turned to the OFF condition when T becomes greater than T HI for the first time during the WARM state or, when the Thermal Shut-Off input is low, if the optional Auto Shut-off Timer 116 times out.
An additional feature of the apparatus is to warn the operator when mineral deposit build up is present in the heating unit chamber in amounts requiring the apparatus to be cleaned of such deposits. Mineral deposits on the walls of the water tube of the heating unit 114 act as an insulator. During the brewing cycle, the temperature of the heating unit is controlled by the cold fluid entering the water tube. As deposits build up the cooling effect is reduced and the heating unit will achieve a higher temperature. This temperature is constantly monitored by the Temperature Sensor 114. If during the BREW cycle, T is greater than T LO , as shown in FIG. 7 in the family of curves above T LO , then the temperature comparator 112 will have an output at T LO . T LO output on line 140 will activate Clean Timer 129 which after a few minutes will activate the Indicator Lights Drive 106 and turn on the Clean light 109. The light will not be activated if the BREW cycle ends before the Clean Timer 129 turns on the Clean light. This assures that T is greater than T LO for a sufficiently long time during the BREW period. The light will remain on throughout the remainder of the cycles and will only be reset if the apparatus is totally reset after a power interruption, or by the starting of another BREW cycle.
A further advantage of the apparatus is that a complete cleaning of the deposits can be accomplished in an unsupervised mode by the operator. Since the states of the apparatus can be selected independently without need to go through the prescribed cycle of BREW-WARM, the user can select the WARM mode and fill the reservoir with a liquid acid solution such as common vinegar. The acid will flow through the check valve 17 into the chamber of the heating unit where it will be heated at the reduced power rate of the WARM mode.
This causes the discharge of the liquid into the infusion basket to be delayed substantially and allow a high residence time of each acid charge in the heating unit. This high residence time causes each successive charge to better dissolve the deposits and at the end of the cycle the heating unit is completely free of deposits.
The Auto Shut Off Timer 116 is an internal counter driven by the System Clock 103 of the apparatus which allows the operator to select different times at which the apparatus will be shut off. Once the selected time span has elapsed the Auto Shut Off Timer will automatically reset the machine through the State Controller 101 to the OFF or A state.
FIGS. 9A-9C show three different embodiments of Vessel Detector 128 of FIG. 5. In all embodiments a magnetic reed switch 154, which is connected in series with Power Control Unit 119 of FIG. 5, is normally closed and thus conducting when the vessel 150 is on the heater of the apparatus. In this condition power is applied to the heating unit during the various states according to the operational demands of the various states. If the vessel 150 is removed in embodiment 9A, actuator lever 151 pivoted around pivot 152 rotates downward by the action of gravity, causing permanent magnet 153, which is rigidly connected to the extension of lever 151, to move away from the reed switch 154 which will thus open interrupting the current flow to the heating means. In embodiment 9B a permanent magnet 153 is installed in the wall of the vessel 150 and the reed switch 154 is installed in the wall of the apparatus to be operatively controlled by the magnet in the vessel. If the vessel is removed, the reed switch will open thus interrupting the current flow to the heating means. In embodiment 9C, the vessel controls the movement of a push button actuator 155 installed in the apparatus. The push button is spring loaded with a bias towards the vessel and is attached to magnet 153. When the vessel is removed, push button actuator 155 moves outwardly towards the vessel side causing magnet 153 to move away from reed switch 154 which will thus open causing an interruption of current flow. In all three embodiments the return of the vessel to the apparatus will cause magnet 153 to come into proximity to switch 154 and thus re-establish current flow.
FIGS. 10A-10B are a logic flow diagram of the condition and apparatus responses of the embodiment represented in block diagram form in FIG. 5. Listed below are the abbreviations used in the logic diagram. Where appropriate, reference is made from the logic flow diagram to the functional block diagram of FIG. 5.
______________________________________PUC: power-up-reset (104 FIG. 5)OSC RUN: oscillator runDVDR OK: divider/counters okayA: state (A)Bt: beeper/counter timer (102 FIG. 5)PB: push-button input (125 FIG. 5)MSI: mode select input (127 FIG. 5)B: state (B)ASI: auto-start inputC: state (C)PN: power ON 100%CLF: clean light OFF, resett: actual elapsed timeTCt: thermistor check timer (113 FIG. 5)ASt: auto-shut-off timerT: temperature sensed by thermistorT.sub.TAT : thermistor assurance temperature (137 FIG. 5)T.sub.LO : low control temperature (140 FIG. 5)T.sub.HI : high control temperature (141 FIG. 5)CLt: clean light timer (129 FIG. 5)CLN: clean light ON, setD: state (D)WPN: warm power ONPF: power OFFTMS: thermal shut-off mode select______________________________________
The logic diagram clearly defines the responses of the apparatus under all possible operating conditions. When power is applied to the apparatus (Power Up Reset), the OSC RUN logic determines if the oscillator is operating. If the answer is negative, the apparatus is shut off. If the oscillator is operating, the DVDR logic (divider/counter) determines if clock counters and dividers are operating. If the answer is NO, the apparatus is shut off. If the divider logic is operating properly, the apparatus activates the A (or OFF) state and Bt (beeper/counter timer) activates a beeper annuniciator. At this stage if PB is activated by the operator, and if MSI (mode select input) is Hi, then the output of MSI will activate the C (or BREW) state and the beeper Bt. If MSI is Low the B (or AUTO) state will be activated. If PB is activated again the Y output will activate the C (or BREW) state. Similarly, a Y output by ASI (auto start) will activate the C (or BREW) state.
Once the C state has been activated, PN (power on) is fully activated and CLF (clean light off) is reset. TCt (start run thermistor check timer) is reset and enabled and concurrently the ASt (auto-shut-off timer) is reset and enabled. During the BREW mode the temperature control logic monitors both the operation of the apparatus and of the monitoring hardware. If T is less than T TAT and the elapsed time t is greater than TCt, the apparatus returns to the A (or OFF) state and operation is discontinued. If t is not greater than TCt and T is no longer less than T TAT , then operation continues.
If during the C state, the condition T HI >T>T LO occurs, then the Clean Light Timer (CLt) is activated. If CLt timer reaches a full time count before the BREW cycle ends, and therefore the condition t>CLt is met, CLN (clean light on) is set and the CLt (clean Light Indicator) is activated. If the BREW state ends before the CLt time reaches a full count, the Clean Light Indicator is not activated. The BREW cycle will end either because PB is activated and apparatus changes to the D (or WARM) state or because the condition T>T HI is satisfied. Once the D state is activated and the Bt audible signal has been generated, if the condition of T>T HI is met, then PF (power off) is active. In this condition, the heating unit receives no energy and it starts cooling off. Then, if T<T LO is met, the WPN (warm power ON) is activated. In this condition a reduced amount of power is delivered to the heating unit to achieve the desired temperature level. At this stage the apparatus can be set to the A (or OFF) state by depressing PB again. If PB has not been depressed or activated and the elapsed time t is >ASt (Auto Shut Off Timer), the apparatus is also set to the A (or OFF) state. If the condition is not met, and T>T.sub. HI is not met, the apparatus continues to operate in the WARM mode. If T>T HI is satisfied, and, if the TMS (Thermal Mode Select) is in the high position (=1), the apparatus is set to the A (or OFF) state. If TMS=0 the apparatus returns to PF and the cycle repeats itself.
In the PF loop, if T<T LO is not satisfied but the lapsed time t>AST is satisfied, the apparatus is set to the A (or OFF) state. If the condition t>AST is not satisfied, the apparatus will stay in the WARM state until the condition is met.
FIG. 11 is a detailed schematic of an embodiment of the invention. L1 and L2 represent the A.C. line input. The values given for some components have been found to be very satisfactory. When power is applied, the power supply, consisting of resistors 337, 373 and 331; capacitors 336, 333 and 330, diodes 335 and 334 and zener diode 332, provide a -5 volts to zener diode 299 which, in this embodiment, is in an integrated custom circuit. The -5 volts is established with respect to the neutral L2 line.
The power supply is a charge pump with positive voltages of line L1 with respect to L2 causing a current flow through diode 335 and negative voltages causing a current flow from the anode of diode 334 to its cathode, thus allowing a negative voltage to be generated at the anode of zener 332.
If the power supply is operating properly, an RC oscillator, constituted of resistors 368 and 369, capacitor 369C and inverters 344, 345 and 346 starts oscillating at 64 KHz. Different frequencies could be obtained by varying the RC time constant. The oscillator output of inverter 344 feeds cascaded counters CTR210, CTR211 and CTR212. They respectively divide the frequency by 16, 512 and 1024. The output of CTR212 at Q11 is thus 7.8 HZ. Inverter 344 also feeds, through gates, counters CTR214, 215, 216 and 217.
Following is a description of the operation of the apparatus shown in FIG. 11.
Power-up Reset, Diagnostic Self-test
When the apparatus is initially turned on, the power-up reset circuit 343 resets counters CTR210, CTR211, and the Power-up Latch 342. The Q bar output of the Power-up Latch 342 goes high, and OR gates 236 and 238 reset flip-flops FF202 and FF203. The Q bar output of flip-flop FF203, via OR gate 253, resets FF206 and the Q bar output of flip-flop FF206 resets flip-flop FF205. Inverter 249 and AND gate 247 form a rising edge pulse generator which is triggered when FF203 is reset. The pulse resets CTR213 via OR gate 340. This enables the beeper output driver circuit, formed by gates 348, 349 and 350, via NOR gate 347. Counter CTR213 is clocked by the Q9 output of counter CTR211 through NOR gate 341. After eight (8) clock pulses, the Q4 output of counter CTR213 goes high and stops further clock input to CTR213 and also disables the beeper output via NOR gate 347. Whenever the apparatus changes state, (i.e. from AUTO to BREW, from BREW to WARM, etc), the beeper output is enabled by a rising edge pulse by the change in state of flip-flops FF202, 203 and 205 and the output of OR gate 340 to the R input of counter CTR213. The beeper output frequency and the length of the beep time are determined by the system clock oscillator frequency and the number of divider stages in counters CTR210 and CTR211.
If the system clock oscillator, is operational, and the system clock dividers CTR210 and CTR211 are counting properly, the Q9 output of counter CTR211 will set the power-up latch 342, and its Q bar output will go low, thus allowing master reset OR gate 236 to go low and reset flip-flop FF203 and permit the state controller to operate starting with state A or OFF.
OFF State (A):
In state A or OFF, the condition of the state controller equivalent of FIG. 5 in the detailed implementation of FIG. 11 can be described as follows: Light Emitting Indicators (LED) AUTO 224, ON 226, BREW 230 and WARM 232 are off. LED indicator CLEAN 228 can either be Off or On depending on the test conditions and results of the previous BREW cycle. Control flip-flops FF202, FF203, FF205 and FF206 are reset to Off, thus the Q output of FF206 is low and turns off AND gate 283, causing triac drive Q 284 and triac TRC 288 to be disabled. The Q bar output of ON flip-flop FF203 resets thermal shut-off latch FF207 and auto-shut off counter/timer CTR217.
Also the Q bar output of the BREW/WARM flip-flop FF205 resets the thermistor check timer CTR216 via OR gate 338 and resets the clean light timer CTR212 with the output of OR gate 339.
Only the push button PB 371 input can cause the state controller to change state in this condition. The PB input is usually in a high condition since resistor R372 is connected to +V. When the PB input is connected to ground by the operator pressing PB, the input goes low and inverter 235 changes the data (D) input of flip-flop FF201 from low to high. The clock (C) input of flip-flop FF201 is connected to the Q7 output of counter CTR211.
The frequency of output Q7 of counter CTR211 is approximately 30 hertz with a period of about 32 milliseconds. The data at flip-flop FF201 can only be clocked at this slow rate allowing transients and contact bounce noise generated by PB to be rejected by the input. When the PB input has been closed during a low to high clock transition, the Q output of flip-flop FF201 will go high for a minimum of 32 milliseconds and will cause the state controller to change from state A (OFF) to state B (AUTO) or state C (BREW) depending on the selected state of the mode-select input (MSI) 306.
AUTO State (B), MSI (Mode Select Input) Low
The MSI input 306 is pulled high by a resistor R370 or a current source. If a jumper connects the MSI input to ground, the low level at the input will cause the state controller to change from the OFF state (A) to the AUTO state (B) when PB 371 is pressed. If Mode Select input 306 is low, OR gate 238 will be low. Since control flip-flops FF202 and FF203 are reset in OFF state (A), OR gate 239 is Off inhibiting FF203 from turning On with the next push button (PB) input impulse. The output of AND gate 237 is high since the Q bar output of flip-flops FF202 and FF203 are high. Thus a push-button input impulse will set flip-flop FF202 to On which in turn lights the AUTO light LED 224 and enables the Auto-Start Input (ASI) 305 via AND gate 233. The state controller will next change from the AUTO state (B) to the BREW state (C) whenever either the auto-start input is pulled low or the push button (PB) input is pulled low.
AUTO State B, Push-button Change
When the apparatus is in AUTO state (B), OR gate 239 is On which in turn enables AND gate 242. XOR gate 243 is on since the Q output of flip-flop FF203 is low and the Q bar of flip-flop FF205 is high. Also AND gate 242 is high to the data (D) input of flip-flop FF203. A push-button (PB) pulse input in these conditions will turn on flip-flop FF203 causing the Q output of flip-flop FF203 to go high and reset flip-flop FF202 via OR gate 238. This sequence initiates the BREW state (C) described in detail below.
AUTO State (B), Auto-start Input Change
When in the AUTO state (B), if the auto-start input (ASI) 305 is pulled low, inverter 221 and NOR gate 222 generate a pulse which sets flip-flop FF203 on. The Q output of flip-flop FF203 thus goes high, resetting flip-flop FF202 via OR gate 238 as before, and the BREW state (C) is initiated.
OFF State (A), Push-button Input Change with MSI High
When the mode select input 306 is high, it locks flip-flop FF203 in a reset condition via OR gate 238. If flip-flop FF203 is reset and flip-flop FF205 is reset, then XOR gate 243 is high. AND gate 242, which is enabled by OR gate 239 and XOR gate 243, sets the data input of flip-flop FF203 high. This means that the state controller, when PB is pressed with the apparatus in the OFF state, will not change to the AUTO state (B), but will change from OFF state (A) to the BREW state (C).
BREW State (C)
In the above conditions, when the push-button input PB is low, the Q output of flip-flop FF201 goes high and flip-flop FF203 is set. The Q output of flip-flop FF203 goes high and causes the rising edge pulse generator, consisting of inverter 240 and AND gate 241, to send a pulse to the following circuits: OR gate 340 which initiates a beeper cycle via counter CTR213 as previously described; CLEAN light flip-flop FF204; clock input (C) to reset flip-flop FF204 and turn off the CLEAN light LED 228 if it had been set on during the previous BREW cycle; the set (S) input of flip-flop FF205, thus setting it to On causing the BREW (C) state to be initiated; the set (S) input of power control flip-flop FF206 via OR gate 256 and AND gate 254 which set flip-flop FF206 to On enabling the triac output driver 284. Thus a change from state A to state C causes the beeper to sound for about one second, the "ON" light LED 226 to turn On, the BREW light LED 230 to turn On and full power (100%) to be selected. The triac driver is also enabled, and the CLEAN light (LED 228) is turned off if it was on from a previous cycle.
BREW State (C), Thermistor Check Timer Operation
When the BREW cycle begins, flip-flop FF205 is set On and the Q bar output of FF205 is low. The thermistor (TH) 264 is in physical contact with the water tube and heating unit, and measures the temperature T of said heating unit. The thermistor resistance decreases as the measured temperature increases. The voltage at the T node decreases as the measured temperature increases. Resistors R260, R261, R262, R263 form a divider network which sets three reference voltages which correspond to the control temperatures measured by TH. These temperatures can be adjusted by changing the values of resistors R260, R261, R262, R263, and are referred to as T TAT (approximately 80° C.), T LO (approximately 140° C.), and T HI (approximately 170° C.). Resistor R265 and thermistor TH 264 form a divider bridge which is connected in parallel and across the reference divider bridge comprised of resistors R260 through R263 to create a differential measurement bridge which will give a consistent comparison regardless of the voltage level supplying the bridge. When the measured temperature T, is below T TAT , the output of comparator CMP259 is low. When the measured temperature T, is above T TAT , the output of comparator CMP259 is high. Assuming the initial measured temperature T, is room ambient (approximately 23° C.), then the output of comparator CMP259 will be low. Since comparator CMP259 is low and the Q bar output of flip-flop FF205 is low, then the output of OR gate 338 will be low allowing counter CTR216 to begin counting. As the measured temperature T rises above T TAT (80° C.), comparator CMP259 will switch from low to high which will reset counter CTR216. Counter CTR216 is also held in reset, regardless of temperature, if the controller is not in the BREW state (C). If the measured temperature T does not rise above T TAT before counter CTR216 has counted 512 system clock pulses (approximately 1 minute), then the Q10 output of counter CTR216 will go high and through OR gate 360 and master reset OR gate 236 will reset the state controller to the OFF state (A). This situation can occur if one or more of the following conditions are present: a thermistor wire is broken; a thermal fuse is open; the heater element is open; the power triac is open; the receiving vessel detector is open, or any other condition which prevents the heating unit from operating. If the controller fails to sense the necessary increase in measured temperature T it will shut the machine to the OFF state (A). This safety feature is essential for negative temperature coefficient type of thermistors.
BREW State (C), Clean Light Operation
During the brewing period, the water in the heating unit keeps the water tube at a specific temperature. As mineral deposits accumulate on the inside of the water tube, the water tube temperature increases since the scale lining inside the water tube decreases the heat transfer from the heating unit to the water in the water tube. When the measured temperature T exceeds T LO during the brewing period, the output of comparator CMP258 goes low. Flip-flop FF205 is low during the BREW period and comparator CMP258 causes OR gate 339 to go low, enabling clean light counter/timer CTR212 which begins counting. If the BREW state (C) ends before counter CTR212 is finished counting, then the Q bar output of flip-flop FF205 will go high, resetting counter CTR212 via OR gate 339 and the clean light will not be activated. If counter CTR212 reaches a full count before the BREW cycle ends, then the output Q11 of CTR212 will go high and set flip-flop FF204 on and turn on clean light LED 228 via output buffer 207. When flip-flop FF204 is set, its Q bar output goes low and prevents any reset input by flip-flop FF205 from turning the clean light LED 228 off. As indicated earlier, the clean light flip-flop FF204 is reset at the beginning of each BREW cycle by a pulse generator consisting of inverter 240 and AND gate 241, when flip-flop FF203 is set on. If the clean light flip-flop FF204 is off and state control flip-flop FF205 is not in the BREW (ON) condition, the Q bar output of FF205 is high and holds clean light flip-flop FF204 off, clean light LD 228 off and resets counter CTR212.
BREW State (C), Full Power Triac Operation
With the apparatus in the BREW state, the triac output circuits are controlled by power flip-flop FF206 and flip-flop FF205. In the BREW state (C), flip-flop FF205 is set, with its Q output high, and if T is less than T HI , flip-flop FF206 is set via a pulse from inverter 240, AND gate 241, OR gate 256 and AND gate 254. The Q output of flip-flop FF205 which is high, is connected to inverter 275, AND gate 276 and AND gate 277. AND gate 277 is thus enabled permitting the output of the zero crossing delay counter, CTR214, to trigger the output pulse counter CTR215. Resistor R298 connects one side of the A.C. line to the input of the zero crossing detector made up of inverter 295, delay buffer 294, and XOR gate 293. When the line voltage crosses zero with respect to the LINE IN input, XOR gate 293 generates a positive pulse whose length is equal to the time of the delay buffer 294. This pulse resets counter CTR214 causing Q7 to go low. Q7 disables the triac driver output Q284 via AND gate 283 and discharges the phase delay capacitor C267 via inverter 273 and semiconductor Q268 (the phase delay capacitor is utilized in the operation of the WARM state). OR gate 292 is also enabled and counter CTR214 starts counting the 64 KHz system clock. Also, the output of AND gate 277 goes low. When counter CTR214 has counted 40 clock cycles, its Q7 output goes high. This enables triac driver output Q284 via AND gate 283 and turns off Q268 via inverter 273, allowing capacitor C267 to begin charging. It also disables OR gate 292, stopping counter CTR214, and causes AND gate 277 to go high, causing OR gate 278 to go high. A rising edge pulse generator formed by AND gate 280 and delay inverter 279, resets CTR215 just after the system clock's signals rising edge. The Q2 output of counter CTR215 goes low, turning on triac driver Q284 via inverter 282 and AND gate 283. Q2 also enables OR gate 281. After two system clock cycles, the Q2 output of counter CTR215 goes high and turns off triac driver Q284 via inverter 282 and AND gate 283. It also disables OR gate 281, stopping counter CTR215 until the next reset pulse from AND gate 280. This circuitry allows triac TRC288 to be fired approximately 600 microseconds after every zero A.C. line crossing, and reduces the operating supply current by limiting the triac's firing pulse width to 32 microseconds. This also minimizes heat dissipation in the triac gate. The triac effectively fires continuously, supplying full power to the heater assembly. When T is greater than T HI , due to lack of water in the heater unit at the end of the BREW cycle, then comparator CMP257 will go high and reset FF206 via OR gate 253. The Q bar output of flip-flop FF206 goes high and resets flip-flop FF205. FF205 is now in the WARM (D) state, and the Q output of FF206 is low, which disables the triac driver Q284 via AND gate 255 and AND gate 283 turning all power to the heater off.
WARM State (D), Phase Delay Triac Power Control
When flip-flop FF205 is reset, its Q output is low and the BREW light LED 230 turns off. Also the WARM light LED 232 is turned on while the ON light LED 226 remains on. AND gate 277 is disabled by the Q output of flip-flop FF205 and AND gate 276 is enabled through inverter 275. The triac firing is now controlled by the phase delay timing circuit which consists of comparator CMP272, AND gate 274, inverter 273 and output driver Q268. When the A.C. line zero crossing detector senses a zero volt line crossing, counter CTR214 is reset as described above and the Q7 output of counter CTR214 goes low for approximately 600 microseconds. During this time, the triac output driver Q284 is disabled via AND gate 283 which is connected to the Q7 output of counter CTR214. AND gate 274 is connected to counter CTR214 output Q7 which disables any output from comparator CMP272. Inverter 273 is connected to counter CTR214 output Q7 which turns output driver Q268 on, thus discharging the phase delay timing capacitator C267. When capacitor C267 is discharged, the voltage at node TC IN is near zero and therefore the output of comparator CMP272 is low. When counter CTR214 reaches the full count, its Q7 output goes high causing inverter 273 to turn off output driver Q268, thus allowing timing capacitor C267 to begin charging through resistor R266. AND gates 274 and 283 are also enabled. Resistors R270, R269, and R271 form an adjustable reference bridge. The reference voltage can be raised or lowered by rotating control R271. When R271 is rotated fully clock-wise, Vref is at its lowest value which allows for the earliest phase firing of the triac TRC288 and the highest level of keep-warm wattage. This sets Vref at the input of comparator CMP272. When the voltage on capacitator C267 goes above Vref, the output of comparator CMP272 goes high, AND gate 274 goes high, AND gate 276 goes high, OR gate 278 goes high and the triac pulse is generated as previously described. Thus the triac fires in a phase delayed manner due to the charging of C267 and therefore reduces the wattage available to the heating unit to keep the beverage in the vessel warm. The wattage range can be changed by changing resistors R269 and R270. The configuration, shown in FIG. 11 provides for approximately 0 to 10% of the full power wattage.
During the WARM cycle, if temperature T becomes greater than T HI , the output of comparator CMP257 goes high and FF206 is reset via OR gate 253. This disables triac driver Q284 since the Q output of FF206 is low, AND gate 255 goes low and AND gate 283 goes low, turning triac driver Q284 off. With power off, the temperature starts decreasing and when temperature T goes below T LO , comparator CMP258 goes high causing OR gate 256 to go high and flip-flop FF206 to be set. The Q output of flip-flop FF206 goes high causing AND gate 255 to go high and AND gate 283 is enabled. Phase delayed firing pulses are sent to the triac TRC288 via output driver Q284. The heating unit operates again with reduced warming wattage to maintain beverage temperature in the receiving vessel.
WARM State (D), Automatic Thermal Shut-off
When in the WARM state (D), flip-flop FF205 is reset and its Q bar output is high. When changing from the BREW state (C) to the WARM state (D), flip-flop FF206 is reset and its Q bar output is high. To prevent thermal shut-off flip-flop FF207 from turning on during the BREW or WARM transition, flip-flop FF206 is reset before flip-flop FF205 and low data are clocked by flip-flop FF207, and its Q1 output remains low. When the temperature T goes lower than T LO , the output of comparator CMP258 goes high, setting flip-flop FF206 causing its Q bar output to be low. If T should go above T HI for a second time while in the WARM state (D), the output of comparator CMP257 goes high, resetting flip-flop FF206 via OR gate 253. Since flip-flop FF205 is already reset and its Q bar output is high; when the Q bar output of FF206 goes high, it sets flip-flop FF207, causing its Q1 output to go high. If the thermal shut-off input 307 is not connected to ground, the internal pull-up resistor 364 will enable AND gate 261. When flip-flop FF207 goes high, AND gate 261 goes high, causing master reset OR gate 236 to reset the state machine controller to the OFF state (A).
If the thermal shut-off input is connected to ground, then any output from flip-flop FF207 is ignored and the controller will not be reset to the OFF state (A). Flip-flop FF206 will toggle off when the temperature T rises above T HI and will toggle on when the temperature T falls below T LO , thus maintaining a suitable control temperature limit.
WARM State (D), Automatic Time Shut-off
When the controller is in either BREW state (C) or in WARM state (D), counter CTR217 is enabled when its reset input goes low. CTR217 is connected to flip-flop FF203 whose Q bar output is low whenever the controller is in the BREW or WARM state. Counter CTR217 has four outputs which correspond to four shut-off times. Each shut-off time is two times longer than the preceding time, i.e. approximately 35, 70, 140 and 280 minutes. To select the proper time, decoder select logic is used so that two input pins can select the four times. The decoder select logic consists of inverters 362 and 363, AND gates 359, 351, 358, 352, 357, 353, 356 and 354 and OR gate 355. If Select Input Pins A and B are low, then inverters 363 and 362, and AND gates 359, 358, 357 and 356, decode the binary 00 code so that the output of AND gate 359 is high. This enables AND gate 359 to select counter CTR217's Q15 output via AND gate 351 and OR gate 355. When counter CTR217 reaches the proper count, Q15 goes high, AND gate 351 goes high, OR gate 355 goes high, OR gate 360 goes high and master reset OR gate 236 goes high, resetting the controller to the OFF state (A). The same scenario occurs for the other binary selections: if A=1 and B=0, this combination selects AND gates 358 and 352 for a shut-off time of 70 minutes; if A=0 and B=1, the combination selects AND gates 357 and 353 for a shut-off time of 140 minutes; and if A=1 and B=1, the combination selects AND gates 356 and 354 for 280 minutes.
Beverage Vessel Detection and Triac Power Control
A means to control the triac is provided so that when the beverage vessel or decanter is removed from the heating means, the triac is disabled and powder for the heating unit is turned off. Several methods could be used to accomplish this. Switch 286 could be a reed switch as shown in FIGS. 9A to 9C. In another embodiment a mechanical switch 286 is connected between the triac driver output pin and the junction of the triac TRC288 gate and resistor R287. If the switch is mechanically connected so that it is closed when the beverage vessel is placed on the heating unit, the triac will operate normally as previously described. If the beverage vessel is removed, or improperly placed on the heating unit, then the switch will be open and the triac will remain off regardless of the state of the controller. A further method to accomplish the beverage vessel detection comprises the detection switch being connected to a fourth input of AND gate 283. The fourth input to this gate is connected to ground via a pull-down resistor and the switch. The switch is closed when the beverage vessel is in the correct position. AND gate 283 would become disabled whenever the beverage vessel is missing or incorrectly placed on the heating unit. With the vessel missing the fourth input to AND gate 283 goes low and disables triac output driver Q284, leaving triac TRC288 off. Therefore no power would be supplied to the heating unit.
Thermal fuses 289 and 291 are added as a precaution in case of a system failure resulting in the heating unit 290 becoming excessively hot.
A large family of simpler apparatus relying on only a portion of the features contained in the invention will be obvious to those skilled in the art.
The invention has been described in such terms as to enable a person skilled in the art to practice the invention, but variations and modifications within the spirit and scope of the invention falling within the scope of the claims may occur to those skilled in the art to which the invention pertains.
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An automatic electric maker for coffee or the like, having user selectable AUTO, BREW, WARM or OFF modes. The temperature of the WARM mode is selectable by applying partial power to the heating element. Full power can be triggered using a phase controlled triggerable semiconductor. Monitoring devices measure temperature and time to control the operator of the apparatus and to detect malfunction. A temperature comparator is provided to determine if the water conduit should be cleaned and to determine if the BREW state of the machine should be converted to the WARM state, and to place the system in the OFF state if necessary.
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This is a continuation-in-part of U.S. patent application Ser. No. 13/998,088, filed on Sep. 30, 2013, which claims the benefit to the priority of U.S. Provisional Patent Application Ser. No. 61/797,042, filed on Nov. 28, 2012. The teaching of U.S. patent application Ser. No. 13/998,088 are incorporated herein in their entirety.
FIELD OF THE INVENTION
The present invention relates generally to a polymeric composition which can be utilized in manufacturing a wide variety of articles of manufacture. This polymeric composition offers an excellent combination of tensile strength, flexural modulus, and impact strength and is made with a large quantity of micronized rubber powder from recycle streams, such as discarded tires and industrial rubber products. One embodiment of the present invention relates to materials and compounds using micronized or pulverized rubber powder as a component to enhance the physical properties or reduce cost of finished products, such as tuber or flat strips in highway delineators, road markers, utility line markers, and vent tubes, for example the vent tubes used on Port-A-Johns).
BACKGROUND OF THE INVENTION
Millions of used tires, hoses, belts and other rubber products are discarded annually after they have been worn-out during their useful service life. These used rubber products are typically hauled to a dump or simply burnt as fuel after they have served their original intended purpose. A limited number of used tires are utilized in building retaining walls, as guards for protecting boats, and in similar applications. Some tires are ground into powder form to be used in various applications, such as tire compounds, binders for asphalt, mulch, fillers for a variety of low performance rubber products, sports field and playground applications, and the like. However, a far greater number of tires, hoses and belts are simply discarded or burnt.
The recycling of cured rubber products has proven to be extremely challenging and problematic. Recycling cured rubber products (such as, tires, hoses and belts) is problematic because, in the vulcanization process, the rubber becomes crosslinked with sulfur into a formed structure. The sulfur crosslinks are very stable and the vulcanization process is extremely difficult to reverse. After vulcanization, the crosslinked rubber becomes thermoset and cannot easily be reformed into other products. In other words, the cured rubber cannot be melted and reformed into other products like metals or thermoplastic materials. Thus, cured rubber products cannot be simply melted and easily recycled into new products.
Since the discovery of the rubber vulcanization process by Charles Goodyear in the nineteenth century, there has been interest in the recycling of cured rubber. A certain amount of cured rubber from tires and other rubber products is shredded or ground to a small particle size and incorporated into various products, including rubber products, as a type of filler. For instance, ground rubber can be incorporated into asphalt for surfacing roads or parking lots. Small particles of cured rubber can also be included in rubber formulations for new tires and other rubber products. However, it should be understood that such recycled rubber which has simply been ground to a small particle size serves only in the capacity of a filler because it was previously cured and does not bond to an appreciable extent to the virgin rubber in the rubber formulation. Therefore, recycled rubber is typically limited to lower loadings due to poor compound processing (compounds become drier with higher loadings) as well as higher loadings leading to unacceptable cure properties. Rubber compositions which contain high levels of ground rubber from previously cured products also typically have compromised physical characteristics, such as lower tensile strength, lower impact strength, low abrasion resistance, and the like. These problems have accordingly greatly limited the quantity of ground rubber from recycled products which can be incorporated into new rubber products.
Various techniques for devulcanizing cured rubber have been developed. Devulcanization offers the advantage of rendering the rubber suitable for being reformulated and recurred into new rubber articles if it can be carried out without degradation of the rubber. In other words, the rubber could again be used for its original intended purpose. However, none of the devulcanization techniques previously developed have proven to be commercially viable at high loadings. For example, some devulcanized materials may be used at loadings of 3-5%. However, above this level the properties of the new rubber article are diminished. This renders them unsuitable for high performance applications, such as vehicle tires, power transmission belts, conveyor belts, hoses, windshield wiper blades, and the like. In other cases, the devulcanized materials are unsuitable for processing at high loadings into rubber compounds. These processing challenges can include short cure times (scorch), too little tack, too high of a viscosity, and poor mill handling and extrusion quality. A renewable material that can be used in high performance applications at loadings of 5% and higher is accordingly needed so that recycled rubber can be used in manufacturing products having higher demands on performance.
U.S. Pat. No. 4,104,205 discloses a technique for devulcanizing sulfur-vulcanized elastomer containing polar groups which comprises applying a controlled dose of microwave energy of between 915 MHz and 2450 MHz and between 41 and 177 watt-hours per pound in an amount sufficient to sever substantially all carbon-sulfur and sulfur-sulfur bonds and insufficient to sever significant amounts of carbon-carbon bonds.
U.S. Pat. No. 5,284,625 discloses a continuous ultrasonic method for breaking the carbon-sulfur, sulfur-sulfur and, if desired, the carbon-carbon bonds in a vulcanized elastomer. Through the application of certain levels of ultrasonic amplitudes in the presence of pressure and optionally heat, it is reported that cured rubber can be broken down. Using this process, the rubber becomes soft, thereby enabling it to be reprocessed and reshaped in a manner similar to that employed with previously uncured elastomers.
U.S. Pat. No. 5,602,186 discloses a process for devulcanizing cured rubber by desulfurization, comprising the steps of: contacting rubber vulcanizate crumb with a solvent and an alkali metal to form a reaction mixture, heating the reaction mixture in the absence of oxygen and with mixing to a temperature sufficient to cause the alkali metal to react with sulfur in the rubber vulcanizate and maintaining the temperature below that at which thermal cracking of the rubber occurs, thereby devulcanizing the rubber vulcanizate. U.S. Pat. No. 5,602,186 indicates that it is preferred to control the temperature below about 300° C., or where thermal cracking of the rubber is initiated. Toluene, naphtha, terpenes, benzene, cyclohexane, diethyl carbonate, ethyl acetate, ethylbenzene, isophorone, isopropyl acetate, methyl ethyl ketone and derivatives thereof are identified as solvents that can be used in the process disclosed by this patent.
U.S. Pat. No. 6,548,560 is based upon the discovery that cured rubber can be devulcanized by heating it to a temperature of at least about 150° C. under a pressure of at least about 3.4×10 6 Pascals in the presence of a solvent selected from the group consisting of alcohols and ketones having a critical temperature within the range of about 200° C. to about 350° C. The molecular weight of the rubber can be maintained at a relatively high level if the devulcanization is carried out at a temperature of no more than about 300° C. This devulcanization technique is reported to not significantly break the polymeric backbone of the rubber or to change its microstructure. In other words, the devulcanized rubber can be recompounded and recurred into useful articles in substantially the same way as was the original (virgin) rubber. This patent more specifically reveals a process for devulcanizing cured rubber into devulcanized rubber that is capable of being recompounded and recurred into useful rubber products, said process comprising (1) heating the cured rubber to a temperature which is within the range of about 150° C. to about 300° C. under a pressure of at least about 3.4×10 6 Pascals in the presence of a solvent selected from the group consisting of alcohols and ketones, wherein said solvent has a critical temperature which is within the range of about 200° C. to about 350° C., to devulcanize the cured rubber into the devulcanized rubber thereby producing a slurry of the devulcanized rubber in the solvent; and (2) separating the devulcanized rubber from the solve.
U.S. Pat. No. 5,770,632 discloses a process for reclaiming elastomeric material from elemental sulphur-cured elastomeric material having a vulcanized network without using hexamethylene tetramine, by treating the sulphur-cured elastomeric material having a vulcanized network with one or more rubber delinking accelerators selected from the group of zinc salts of thiocarbamates and zinc salts of dialkyl dithiophosphates, 2-mercaptobenzothiazole or derivatives thereof, thiurams, guanidines, 4,4′-dithiomorpholine and sulphenamides, and a zinc oxide activator in an amount sufficient to act as an activator for the accelerator(s) to delink the elastomeric material at a temperature below 70° C., whereby the vulcanized network is opened up or delinked to provide a curable reclaimed elastomeric material capable of being vulcanized without adding rubber vulcanizing chemicals. The technique described in this patent also includes compositions capable of delinking the vulcanized network of sulphur-cured elastomeric materials including the accelerators and activator described above. The obtained recycled, or reclaimed, elastomeric material has desired physical and dynamic characteristics that render it suitable for use in molded goods or for admixture with fresh compounds in tires and related products.
U.S. Pat. No. 6,831,109 described a modifier for devulcanization of cured elastomers, and especially vulcanized rubber, said modifier containing a first chemical substance, which is disposed towards on and the formation of an organic cation and amine, and further containing a second chemical substance as promoter of dissociation of the first chemical substance, said promoter containing a functional group constituting an acceptor of said amine.
U.S. Pat. No. 6,541,526 describes a mechanical/chemical method composition for the de-vulcanization of rubber is reported to maintain the macromolecules in the composition and to render the sulfur therein passive for later re-vulcanization. This process is also reported to be cost effective, environmentally friendly and to produce high quality de-vulcanized rubber to replace virgin rubber. According to the method of U.S. Pat. No. 6,541,526 waste rubber is shredded, crushed and metal is removed. Then the modifying composition is added as the particles of shredded waste rubber are poured between two rollers that further crush the particles. The modifying composition is a mixture of ingredients which include, by weight, the following components: (1) between approximately 76% and approximately 94% of a proton donor that breaks sulfur to sulfur bonds in the waste rubber; (2) between approximately 1% and approximately 5% of a metal oxide, (3) between approximately 1% and approximately 5% of an organic acid having between 16 and 24 carbon atoms per molecule, (4) between approximately 2% and approximately 10% of a vulcanization inhibitor and (5) between approximately 2% and approximately 10% of a friction agent.
United States Patent Application Publication No. 2010/0317752 described a method which is reported to be effective in recycling vulcanized elastomeric materials via a cost effective devulcanization process which opens up or “delinks” the crosslinks of the vulcanized network structure in used vulcanized elastomers without unduly degrading the backbone of the rubbery polymer. This patent more specifically discloses a delinking composition in the form of a combined solid dose comprising: (i) one or more elastomer delinking accelerators selected from the group consisting of zinc salts of thiocarbamates and zinc salts of dialkyl dithiophosphates; and (ii) one or more elastomer delinking accelerators selected from the group consisting of 2-mercaptobenzothiazole or derivatives thereof, thiurams, guanidines, 4,4′-dithiomorpholine and sulpenamides; and (iii) at least one elastomer delinking activator. However, this patent absolutely requires as essential ingredients zinc salt, an elastomer delinking accelerator and a delinking activator.
None of the techniques described in these foregoing patents have proven to be commercially viable and the recycled rubber made by these processes have not proven to be feasible for use at high loadings in value added applications, such as tires, conveyor belts, power transmission belts, hoses, air springs, windshield wiper blades, and the like. In fact, to date very little characterization data has been presented to substantiate statements regarding the selectivity of sulfur-sulfur or sulfur-carbon bonds being broken instead of carbon-carbon bonds within the vulcanized rubber compound network. Accordingly, the suitability of any of these recycled rubbers as a direct replacement for virgin rubber in manufacturing new rubber products has not been substantiated.
Cured rubber articles can successfully be ground into a powder and used in manufacturing a wide variety of products. For instance, reclaimed elastomeric materials, such as reclaimed elastomers, ground tire rubber (GTR), and micronized rubber powders (MRP), which include vulcanized elastomeric materials, are used in a variety of products. For instance, micronized rubber powders are commonly used as fillers in rubber, asphalt, and plastic articles. More specifically, micronized rubber powders are presently being utilized as fillers in tires, industrial rubber products (hoses, power transmission belts, conveyor belts, floor mats), asphalt products (paving formulations and roofing shingles) and a wide array of other products. The utilization of reclaimed elastomers in such rubber products is typically significantly less expensive than using virgin materials and leads to an overall reduction in manufacturing costs. The use of reclaimed material is also environmentally advantageous in that it prevents the cured rubber recovered from postconsumer and industrial sources from going to landfills or simply being burned. Finally, the use of recycled ground tire rubber and micronized rubber powders provides a strategic supply chain hedge against petroleum-based supply chain price and supply volatility.
Today, devulcanized rubber material known as reclaim exhibits excellent processability but poor cure properties in compounds at loadings above 3-5%. Micronized rubber powder (MRP) shows acceptable cure properties, yet at higher loadings (above 5%), compound processability begins to suffer.
Generally, ground tire rubber (GTR) consists of particle size distributions that range from a diameter of about 0.5 mm to about 5 mm which can be produced by a variety of techniques including ambient temperature and cryogenic grinding methods. Micronized rubber powders (MRP) typically contain a significant fraction of rubber particles having a particle size of less than 100 microns. In any case, ground tire rubber and micronized rubber powders are commonly designated by mesh size. For example, powders in the size range of 10-30 mesh normally are considered to be ground tire rubber while powders having a smaller particle size which is within the range of 40-300 mesh are generally considered to be micronized rubber powder. Micronized rubber powder is typically more expensive to make by virtue of requiring more processing and/or more demanding processing conditions to attain the smaller particle size. For this reason, ground tire rubber is typically used in low performance applications, such as floor mats, with micronized rubber powder only being utilized in more demanding applications, such as tires, where the additional cost can be justified.
The reclaimed elastomeric polymers which are used as the raw material for making ground tire rubber and micronized rubber powder, such as scrap tire rubber, are cured (previously vulcanized) rubbers. They are accordingly relatively inert particles which are essentially non-reactive with virgin elastomers, which results in compromised processing and properties at high loadings. The use of such reclaimed rubbers in manufacturing new rubber products often leads to a compromised level abrasion resistance which greatly limits the level at which they can be incorporated into products which are subjected to abrasive forces during their service life, such as tire tread formulations, windshield wiper blades, and conveyor belts, and the like.
Even though many uses for recycled rubber have been developed over the years there remains a need for using recycled rubber in large quantities in high performance applications. In other words, there is a long-felt but unresolved need for applications in which ground tire rubber and micronized rubber powders can be used in large quantities in manufacturing high performance articles of manufactured. In other words, it would be highly desirable for these products to have the attributes of those which are at least as good or better than those made utilizing virgin rubber.
SUMMARY OF THE INVENTION
This invention relates to rubber formulations which are useful as a structural material for utilization in manufacturing a wide variety of articles having excellent impact strength and tensile strength. These articles of manufacture can be made to have a unique combination of rigidity, strength and flexural properties while maintaining excellent impact strength and durability. Additionally, articles made with the rubber formulations of this invention can essentially return to their original shape after being deformed by being impacted with a foreign object. The rubber formulations of this invention can accordingly be used in making various articles of manufacture having a highly desirable combination of physical properties which can provide them with beneficial characteristics which could not otherwise be attained. For instance, the rubber formulations of this invention are of particular value in vehicle mud flaps, tuber or flat strips for highway delineators, road markers, utility line markers, vent tube, and the like.
The subject invention more specifically reveals a polymeric formulation which is useful as a structural material for manufacturing a wide variety of articles of manufacture, said polymeric formulation being comprised of (1) about 45 weight percent to about 85 weight percent of a micronized rubber powder, (2) from about 15 weight percent to about 45 weight percent of a metallocene polyolefin elastomer, and (3) from about 1 weight percent to about 10 weight percent of a maleic anhydride grafted polyethylene.
The present invention further reveals an extrudable flexible composition for use in articles which return to their original shape when deformed comprising: between 1 weight percent and 90 weight percent of a micronized rubber powder, a polyolefin-based elastomer, and a compatabilizer. In these compositions the polyolefin-based elastomer will typically be a polyethylene-based elastomer or a polypropylene-based elastomer. It is generally preferred for the polyolefin-based elastomer to be a metallocene polyolefin elastomer, such as a metallocene polyethylene elastomer or a metallocene polypropylene elastomer. The micronized rubber powder will typically be a mixture of natural rubber and various synthetic rubbers, including synthetic polyisoprene rubber, emulsion styrene-butadiene rubber, solutions styrene-butadiene rubber, high cis-1,4-polybutadiene rubber, styrene-isoprene-butadiene rubber, and the like. In one embodiment of this invention, the micronized rubber powder is present in the extrudable flexible composition at a level which is within the range of 45 weight percent to about 85 weight percent and is preferably present at a level which is within the range of 60 weight percent to about 80 weight percent. The compatabilizer can be a mixture of light color aliphatic hydrocarbon resins or a maleic anhydride grafted polyolefin, such as a maleic anhydride grafted polyethylene or maleic anhydride grafted polypropylene.
The subject invention also discloses an extrudable durable composition which retains its shape in finished products comprising: about 40 weight percent to 60 weight percent of a micronized rubber powder, about 10 weight percent to about 50 weight percent of a polyolefin-based elastomer, about 1 weight percent to about 10 weight percent of a compatabilizer, and about 1 weight percent to about 5 weight percent of a color concentrate. In these compositions the polyolefin-based elastomer will typically be a polyethylene-based elastomer or a polypropylene-based elastomer. It is generally preferred for the polyolefin-based elastomer to be a metallocene polyolefin elastomer, such as a metallocene polyethylene elastomer or a metallocene polypropylene elastomer. The micronized rubber powder will typically be a mixture of natural rubber and various synthetic rubbers, including synthetic polyisoprene rubber, emulsion styrene-butadiene rubber, solutions styrene-butadiene rubber, high cis-1,4-polybutadiene rubber, styrene-isoprene-butadiene rubber, and the like. The compatabilizer can be a mixture of light color aliphatic hydrocarbon resins or a maleic anhydride grafted polyolefin, such as a maleic anhydride grafted polyethylene or maleic anhydride grafted polypropylene.
One aspect of the subject invention is based upon the discovery of how to manufacture road markers and highway delineators from a compounded mixture of polymers and pulverized or micronized rubber powder, using a multi-layer plastic extrusion process on industry standard extrusion equipment.
Utility line markers, road markers and highway safety delineators are used along roads and highways to mark road boundaries, exits, and underground service pipes or cables. The problems with current delineators is their limited ability to be impacted by a vehicle, such as an automobile or truck, traveling at 55 mph (miles per hour) or even faster or farm implements, and to return to the vertical position at cold or elevated temperatures. The cost of delineators or posts of current design: ranging from standard commodity thermoplastics to expensive performance based polymers, such as TPU (thermoplastic polyurethane) is reduced in the practice of this invention by using available lower cost, recycled tire and scrap rubber powder sources.
The finished tube or flat delineator is protected from deteriorating from ultra-violet rays from the sun by a multi-layer thin cap coat cover of a polymer and color concentrate. One aspect of this invention is based upon the discovery that the blending of various levels of micronized/non-micronized rubber; recycled and or virgin blends into a formulated array of thermoset/thermoplastic blends to achieve economic performance results for impact regardless shape, attachment method or spring back mechanisms. The micronized rubber particles act as a filler to make an un-extrudable thermoset/thermoplastic blend more viscous and thus extrudable. It is the excellent filler loading acceptance and the elasticity performance nature of Vistamax 3020 or equivalent (propylene-based elastomer, using ExxonMobil Chemical's EXXPOL catalyst technology or equivalent) that provides the desired characteristics.
One aspect of this invention is based upon the use of a mixture of light-colored aliphatic resins to improve the homogeneity of elastomers of different polarity and viscosity during the mixing cycle. Such a mixture of light-colored aliphatic resins is commercially available from Struktol Company of Ameerica of Stow, Ohio and is sold as Struktol® RP 28 which has a softening point of 95-105° C. and a specific gravity of 0.97.
In one embodiment of this invention a rubber/thermoplastic blend is used in a delineator base applications wherein the blend provides an economic advantage over virgin rubber and also enables a stronger chemical bond (with the use of compatibilizers) with the butyl adhesive or epoxy that is used to adhere the base of the delineator to the pavement.
Another object of the subject invention is the provision of a reduced and sustainable carbon foot print of emissions for virgin rubber and the repurposing of some of the large amount of tire scrap accumulating each year around the world. Another object of the present invention is the provision of a composition which itself is recyclable so that, for example, a highway delineator can be recycled by being blended back into new delineator without loss of performance in the new delineators.
Another object of the subject invention is the provision of a composition which can be formed into an elongated flexible tube or profile of resilient thermoplastic/thermoset plastics filled with a rubber blend filler. Another object of the subject invention is the provision of as composition which can be extruded into a shape and which is then capable of being repetitively bent through an angle of 90° and of returning to an upright straight position. In order to duplicate impact testing results 90° flexure was tested via a modified test apparatus using the ASTM D2444-99 test procedure. The falling TPU test utilized a 20 pound, smooth face TPU, dropped repetitively from a height of 11 feet, impacting and passing through the horizontal test sample 18 inches from the mounted base and flexing it to a 90° bend. The velocity of the impact was calculated to be 57 mph (miles per hour). The test specimens measured 42 inches in length. The delineator continuously returned to origin. Another object of the invention is the provision of a formed performance base for highway delineators consisting of a resilient thermoplastic/thermoset plastic filled with micronized rubber blend filler. Another object of the present invention is the provision of a composition which can be used in existing mechanical designs without modification of existing form, fit, and function.
One embodiment of this invention is directed to a compounded blend of materials which can be used to make all existing delineator structures as well as new designs. These blends include a matrix of micronized rubber particles (either virgin or recycled) ranging from 1% to 90% load capacity depending on performance desired enveloped into a blend of thermoplastic or thermoset polymer blends. The theory behind the envelopment of rubber particles into a thermoplastic or thermoset blend is to provide the viscosity required to extrude the material through existing, conventional extrusion and sizing equipment. In addition, the micronized rubber powder will act as a filler reducing cost of performance related thermoplastics/thermosets without reducing performance. This invention may or may not utilize a cap stock material to enable processing of the performance portion of the internal blend mix. The cap stock material may also serve as a means to reduce color concentrate cost required to customize the tube per customer specifications. The cap stock material may also be used for the adhesion of reflective tape, in addition to UV protection.
Another object of the present invention is the provision of a cost effective performance based rubber/thermoplastic blend in the manufacturing of the base. It is noted that virgin rubber is an expensive solution for the impact properties desired and performance required. The compounded blend will still offer comparable performance results at an economical value.
Another purpose of the present invention is the provision of a compounded blend that will enable a successful performance drive over test for a utility line marker. An attribute needed for underground line markers, used in the utility industry for identifying the location of underground lines. Numerous underground utility line markers are damaged by farm implements that knock the existing line markers over thereby eliminating their visual purpose. The blend of the subject invention allows the line markers to rebound back to a vertical position to remain visible for their intended purpose.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a co-extrusion operation using two extruders.
FIG. 2 is a block diagram of a co-extrusion operation using three extruders.
DETAILED DESCRIPTION OF THE INVENTION
The polymeric formulation of this invention are comprised of (1) about 45 weight percent to about 85 weight percent of a micronized rubber powder, (2) from about 15 weight percent to about 35 weight percent of a metallocene polyolefin elastomer, and (3) from about 1 weight percent to about 10 weight percent of a maleic anhydride grafted polyethylene. The polymeric formulation of this invention can be made by thoroughly mixing the micronized rubber powder, the metallocene polyolefin elastomer, the maleic anhydride grafted polyethylene, and other desired ingredients in a twin screw extruder to attain an essentially homogeneous mixture of the various ingredients. To attain optimal results the ingredients will be dried before being mixed in the extruder. The ingredient are typically dried to a moisture content of less than 0.5 weight percent and are optimally dried to a moisture content of less than 0.1 weight percent.
The micronized rubber powder can be included in the polymeric formulations of this invention at surprisingly high level with excellent physical properties still being maintained. For instance, the micronized rubber powder will typically be included in the polymeric rubber formulations of this invention at a level which is within the range of 50 weight percent to 85 weight percent or at a level which is within the range of 55 weight percent to 85 weight percent. In some applications it is preferred for the micronized rubber powder to be included in the polymeric rubber formulations of this invention at a level which is within the range of 60 weight percent to 80 weight percent or which is within the range of 65 weight percent to 80 weight percent. In some cases it is preferred for the micronized rubber powder to be included in the polymeric rubber formulations of this invention at a level which is within the range of 70 weight percent to 80 weight percent or which is within the range of 72 weight percent to 78 weight percent.
The micronized rubber powders (MRP) utilized in making the polymeric formulations of this invention typically contain a significant fraction of rubber particles having a particle size of less than 100 microns. In any case, such micronized rubber powders can be designated by mesh size as determined by ASTM D-5603. For example, an 80 mesh rubber powder is one in which 90% of particles pass through an 80 mesh screen. There is no defined minimum particle size, therefore the particle size distribution can be quite broad or even multi-modal. Powders in the size range of 40 mesh to 300 mesh are generally considered to be micronized rubber powder.
The reclaimed elastomeric polymers which are used as the raw material for making micronized rubber powder, such as scrap tire rubber, are cured (previously vulcanized) rubbers. They are accordingly relatively inert particles which are essentially non-reactive with virgin elastomers. In one specific embodiment of this invention the micronized rubber can be made utilizing the cryogenic grinding system described in U.S. Pat. No. 7,445,170 or with an impact mill as described in U.S. Pat. No. 7,861,958. The teachings of U.S. Pat. No. 7,445,170 and U.S. Pat. No. 7,861,958 are incorporated herein for purposes of describing useful techniques and equipment which can be employed in making micronized the rubber formulations of this invention. Micronized rubber powder can also be made in many other ways, such as but not limited to a wet grinding process, ambient temperature grinding procedures, and other cryogenic processes. In any case the micronized rubber powder will typically be comprised of a mixture of various cured rubbery polymers including natural rubber, synthetic polyisoprene rubber, emulsion styrene-butadiene rubber, solution styrene-butadiene rubber, styrene-isoprene-butadiene rubber, and a wide variety of additional cured rubbers.
The micronized rubber powder will typically have a particle size which is within the range of 40 Mesh to 300 Mesh. The micronized rubber will normally have a particle size which is within the range of 80 Mesh to 200 Mesh and will preferable be of a particle size which is within the range of 100 Mesh to 160 Mesh. In one embodiment of this invention the micronized rubber can be of a particle size of 80 Mesh with less than 10% by weight of the particles of the micronized rubber powder being capable of passing through a 200 Mesh screen. In another embodiment of this invention the micronized rubber can be of a particle size of 140 Mesh with less than 10% by weight of the particles of the micronized rubber powder being capable of passing through a 200 Mesh screen. A micronized rubber powder that can be utilized in the practice of this invention is MicroDyne 400 which is commercially available from Lehigh Technologies of Tucker, Ga. MicroDyne 400 has a maximum moisture content of 0.5 weight percent, contains from 25 to 35 weight percent carbon black, and has a specific gravity of 1.14±0.03. MicroDyne 400 also has a particle size distribution wherein less than 1% of particle are larger than 600μ and less than 10% are larger than 400μ.
The metallocene polyolefin elastomer will typically be included in the polymeric formulations of this invention at a level which is within the range of 15 weight percent to 45 weight percent and will more typically be included at a level which is within the range of 15 weight percent to 40 weight percent. In many cases the metallocene polyolefin elastomer will be included in the polymeric formulations of this invention at a level which is within the range of 20 weight percent to 35 weight percent or which is within the range of 15 weight percent to 40 weight percent. In one embodiment of this invention the metallocene polyolefin elastomer is included in the polymeric formulations of this invention at a level which is within the range of 22 weight percent to 28 weight percent.
The metallocene polyolefin elastomer will typically be an ethylene/α-olefin interpolymer or a propylene/α-olefin interpolymer. In one embodiment of this invention the metallocene polyolefin elastomer can be a blend of an ethylene/α-olefin interpolymer and a propylene/α-olefin interpolymer.
Although ethylene is not generally characterized as being an α-olefin, as used herein the term propylene/α-olefin interpolymer includes propylene-ethylene interpolymers. Such propylene/α-olefin copolymers are further described in detail in U.S. Pat. No. 6,960,635 and U.S. Pat. No. 6,525,157. The teaching of U.S. Pat. No. 6,960,635 and U.S. Pat. No. 6,525,157 are incorporated herein by reference for the purpose of describing metallocene polyolefin elastomers which can be used in the practice of this invention. Such propylene/α-olefin copolymers are commercially available from The Dow Chemical Company, under the tradename VERSIFY Elastomers and Plastomers, and from ExxonMobil Chemical Company, under the tradename VISTAMAXX.
In one embodiment, the propylene/α-olefin copolymer, is characterized as having substantially isotactic propylene sequences. The term “substantially isotactic propylene sequences” as used herein means that the sequences have an isotactic triad (mm) measured by 13 CNMR of greater than about 0.85; in the alternative, greater than about 0.90; in another alternative, greater than about 0.92; and in another alternative, greater than about 0.93. Isotactic triads are well-known in the art and are described in, for example, U.S. Pat. No. 5,504,172 and International Publication No. WO 00/01745, which refer to the isotactic sequence in terms of a triad unit in the copolymer molecular chain as determined by 13 CNMR spectra. The teachings of U.S. Pat. No. 5,504,172 and International Publication No. WO 00/01745 are incorporated herein by reference for the purpose of describing such isotactic triads.
The propylene/α-olefin copolymer may have a melt flow rate in the range of from 0.1 to 25 g/10 minutes, measured in accordance with ASTM D-1238 (at 230° C./2.16 Kg). All individual values and sub-ranges from 0.1 to 25 g/10 minutes are included herein and disclosed herein; for example, the melt flow rate can be from a lower limit of 0.1 g/10 minutes, 0.2 g/10 minutes, or 0.5 g/10 minutes to an upper limit of 25 g/10 minutes, 15 g/10 minutes, 10 g/10 minutes, 8 g/10 minutes, or 5 g/10 minutes. For example, the propylene/α-olefin copolymer may have a melt flow rate in the range of 0.1 to 10 g/10 minutes; or in the alternative, the propylene/α-olefin copolymer may have a melt flow rate in the range of 0.2 to 10 g/10 minutes.
The propylene/α-olefin copolymer has a crystallinity in the range from 1 percent by weight (a heat of fusion of 2 Joules/gram (J/g)) to 30 percent by weight (a heat of fusion of 50 Joules/gram). All individual values and sub-ranges from 1 percent by weight (a heat of fusion of 2 Joules/gram) to 30 percent by weight (a heat of fusion of 50 Joules/gram) are included herein and disclosed herein; for example, the crystallinity can be from a lower limit of 1 percent by weight (a heat of fusion of 2 Joules/gram), 2.5 percent (a heat of fusion of 4 Joules/gram), or 3 percent (a heat of fusion of 5 Joules/gram) to an upper limit of 30 percent by weight (a heat of fusion of 50 Joules/gram), 24 percent by weight (a heat of fusion of 40 Joules/gram), 15 percent by weight (a heat of fusion of 24.8 Joules/gram) or 7 percent by weight (a heat of fusion of 11 Joules/gram). For example, the propylene/α-olefin copolymer may have a crystallinity in the range of from 1 percent by weight (a heat of fusion of 2 Joules/gram) to 24 percent by weight (a heat of fusion of 40 Joules/gram); or in the alternative, the propylene/α-olefin copolymer may have a crystallinity in the range of from 1 percent by weight (a heat of fusion of 2 Joules/gram) to 15 percent by weight (a heat of fusion of 24.8 Joules/gram); or in the alternative, the propylene/α-olefin copolymer may have a crystallinity in the range of from 1 percent by weight (a heat of fusion of 2 Joules/gram) to 7 percent by weight (a heat of fusion of 11 Joules/gram); or in the alternative, the propylene/α-olefin copolymer may have a crystallinity in the range of from 1 percent by weight (a heat of fusion of 2 Joules/gram) to 5 percent by weight (a heat of fusion of 8.3 Joules/gram). The crystallinity is measured via DSC method, as described herein. The propylene/α-olefin copolymer comprises units derived from propylene and units derived from one or more α-olefin comonomers. Exemplary comonomers utilized in the propylene/α-olefin copolymer are C 4 to C 10 α-olefins; for example, C 4 , C 6 , and C 8 α-olefins. A particularly preferred polyethylene/α-olefin copolymer is metallocene propylene-octene copolymer elastomer.
The propylene/α-olefin copolymer comprises from 1 to 40 percent by weight of one or more α-olefin comonomers, including as previously discussed, ethylene. All individual values and sub-ranges from 1 to 40 weight percent are included herein and disclosed herein; for example, the comonomer content can be from a lower limit of 1 weight percent, 3 weight percent, 4 weight percent, 5 weight percent, 7 weight percent, or 9 weight percent to an upper limit of 40 weight percent, 35 weight percent, 30 weight percent, 27 weight percent, 20 weight percent, 15 weight percent, 12 weight percent, or 9 weight percent. For example, the propylene/α-olefin copolymer comprises from 1 to 35 percent by weight of one or more α-olefin comonomers; or in the alternative, the propylene/α-olefin copolymer comprises from 1 to 30 percent by weight of one or more α-olefin comonomers; or in the alternative, the propylene/α-olefin copolymer comprises from 3 to 27 percent by weight of one or more α-olefin comonomers; or in the alternative, the propylene/α-olefin copolymer comprises from 3 to 20 percent by weight of one or more α-olefin comonomers; or in the alternative, the propylene/α-olefin copolymer comprises from 3 to 15 percent by weight of one or more α-olefin comonomers.
In some embodiments of the invention, the propylene/α-olefin copolymer is propylene/ethylene wherein the ethylene is present in amounts from 9 to 15 weight percent of the total propylene/ethylene copolymer weight. All individual values and sub-ranges from 9 to 16 weight percent are included herein and disclosed herein; for example, the comonomer content can be from a lower limit of 9, 10, 11, 12, 13 or 14 weight percent to an upper limit of 10, 11, 12, 13, 14, or 15 weight percent. For example, the propylene/ethylene copolymer may comprise in a weight percent derived from ethylene of from 9 to 15 weight percent, or in the alternative, from 10 to 14 weight percent or in the alternative, from 11 to 13 weight percent.
The propylene/α-olefin copolymer has a molecular weight distribution (MWD), defined as weight average molecular weight divided by number average molecular weight (M w /M n ) of 3.5 or less; in the alternative 3.0 or less; or in another alternative from 1.8 to 3.0.
In one embodiment of this invention, the propylene-α-olefin copolymers are further characterized as comprising (A) between 60 and less than 100, preferably between 80 and 99 and more preferably between 85 and 99, weight percent units derived from propylene, and (B) between greater than zero and 40, preferably between 1 and 20, more preferably between 4 and 16, and even more preferably between 4 and 15, weight percent units derived from at least one of ethylene and/or a C 4 -C 10 α-olefin; and containing an average of at least 0.001, preferably an average of at least 0.005 and more preferably an average of at least 0.01, long chain branches/1000 total carbons, wherein the term long chain branch refers to a chain length of at least one (1) carbon more than a short chain branch, and wherein short chain branch refers to a chain length of two (2) carbons less than the number of carbons in the comonomer. For example, a propylene/1-octene interpolymer has backbones with long chain branches of at least seven (7) carbons in length, but these backbones also have short chain branches of only six (6) carbons in length. The maximum number of long chain branches in the propylene interpolymer is not critical to the definition of this embodiment of the instant invention, but typically it does not exceed 3 long chain branches/1000 total carbons. Such propylene/α-olefin copolymers are further described in details in U.S. Pat. No. 8,420,760; International Publication WO2009/067337A1, and EP0964890B1, each of which is incorporated herein by reference.
The metallocene polyolefin elastomer utilized in the polymeric formulations of this invention can be a single propylene/α-olefin interpolymer or it can be comprise of two or more propylene/α-olefin interpolymers or a combination of two or more embodiments as previously described herein.
The maleic anhydride grafted polyethylene will typically be incorporated into the polymeric formulations of this invention at a level which is within the range of about 1 to about 10 weight percent, based upon the total weight of the polymeric formulation. However, the maleic anhydride grafted polyethylene will more commonly be incorporated into the polymeric formulations of this invention at a level which is within the range of about 2 to about 8 weight percent. The maleic anhydride grafted polyethylene will more commonly be incorporated into the polymeric formulations of this invention at a level which is within the range of about 3 to about 6 weight percent. In most cases the maleic anhydride grafted polyethylene does not provide further benefits at levels of greater than about 5 weight percent. Accordingly, for economic reasons the level of the maleic anhydride grafted polyethylene in the polymeric formulations of this invention will typically not exceed about 5 weight percent. For this reason, it is generally preferred to include the maleic anhydride grafted polyethylene in the polymeric formulations of this invention at a level which is within the range of about 4 weight percent to about 5 weight percent.
The maleic anhydride grafted polyethylene used in the practice of this invention typically has an acid number which is within the range of 5 to 12 mg KOH/gram and more typically has an acid number which is within the range of 6 to 10 mg KOH/gram. In many case it is preferred for the maleic anhydride grafted polyethylene used in the practice of this invention to have an acid number which is within the range of 7 to 9 mg KOH/gram. The maleic anhydride grafted polyethylene used in the practice of this invention will also typically have a Mettler softening point which is within the range of 110° C. to 130° C. as determined by differential scanning calorimetry and a penetration hardness of less than 1 dmm as determined by ASTM D5. The maleic anhydride grafted polyethylene will also typically have a weight average molecular weight (M w ) which is within the range of 45,000 to 85,000 and which is more typically within the range of 55,000 to 75,000. For instance, the maleic anhydride grafted polyethylene can have a weight average molecular weight which is within the range of 60,000 to 70,000.
The maleic anhydride grafted polyethylene which can be utilized in the practice of this invention and techniques for the synthesis of such maleic anhydride grafted polyethylene are described in U.S. Pat. No. 5,955,547 and U.S. Pat. No. 6,046,279. The teachings of U.S. Pat. No. 5,955,547 and U.S. Pat. No. 6,046,279 are incorporated by reference herein.
The rubber formulations of this invention can also include a wide variety of standard rubber compounding ingredients including fillers, antioxidants, processing oils, extender oils, resins, colorants, pigments, and the like. For instance, the rubber formulations of this invention can contain fillers, such as carbon black, reinforcing silica, clay, talc, lignin, and the like.
Examples 1-5
In this experiment a series of polymeric formulations were prepared in accordance with this invention and tested to determine physical properties. In the procedure used the ingredients delineated in Table 1 were dried and mixed in a twin screw extruder to attain homogeneous polymeric blends. The polymeric formulations were then processed into dog-bones for determination of physical properties. The properties of the polymeric formulations made are also shown in Table 1.
TABLE 1
Example
1
2
3
4
5
Composition
Micronized rubber powder
75%
75%
71.4%
71.4%
71.4%
(40 mesh)
Engage ® A1103
25%
—
23.8%
—
11.9%
ethylene-octene elastomer
Vistamaxx ™ 6102
—
25%
—
23.8%
11.9%
ethylene-octene elastomer
Epolene ® C-26 maleic
—
—
4.8%
4.8%
4.8%
anhydride grafted
polyethylene
Physical Properties
Tensile Strength @ break (psi)
221
222
556
607
550
Tensile Elongation @ break (%)
138
203
251
218
232
Flexural Modulus (psi)
428
412
971
3887
946
Flexural Strength @ 5% (psi)
19.0
18.5
43.7
145
41.7
As can be seen from Table 1, the presence of the maleic anhydride grafted polyethylene in the formulations of this invention greatly enhanced the tensile properties and the flexural strength of the formulations made. The excellent tensile properties and flexural strength attained was surprising in light of the high level of micronized rubber included in the formulations made.
Example 6
One embodiment of this invention includes a mix of micronized rubber from Lehigh Technologies, LLC of 120 Royal Woods Court SW, Tucker, Ga. 30084, and Vistamaxx™ propylene based elastomers from Exxon Mobil Chemical Company, of 13501 Katy Freeway, Houston, Tex. 77079-1398. The invention may also include a combination of color concentrate and compatibilizer from Struktol Corporation, of 201 E. Steels Corners Road, P.O. Box 1649, Stow, Ohio 44224-0649 and a powder form of linear low density polyethylene (“LLDPE”). There are varying degrees of performance and cost targets which may be met adding and subtracting portions of the ingredients of the mix.
The addition of a cap coat with a Vistamaxx 3020™ or equivalent molecular blend/loading allows for adhesion of the two layers in the multi-layer extrusion process and also allows both layers to exhibit like performance of elasticity upon impact. The high density polyethylene (“HDPE”) provides a stiffening property to the matrix and may be varied depending upon performance and usage. Higher levels of Vistamaxx™ or similar, may be used depending on the field purpose of the delineator. In addition, varying melt viscosities may be used in any of the layers, depending on performance desired. Construction zone delineators suffer numerous impacts and may or may not require a higher loading or concentration of Vistamaxx™ or equivalent for performance purposes.
It has been determined that micronized powder meshes of all components are optimum in homogenous mixing. It has also been noted that continuous mixing to the throat of the extruder is important to keep a proper proportional balance. In addition, it has also been determined that different melt flow ranges of the materials in the ingredient blend will provide for a homogeneous blend encapsulating the rubber particles and in turn providing performance optimization. It has also been determined that the addition of Maleic Anhydride in the form of MAPE (Maleated Polyethylene), MAPP (Maleated Polypropylene) or maleated natural rubber may enhance the performance characteristics allowing for higher loading content of rubber greater than 50%. This is disclosed in Highly filled thermoplastic elastomers from ground tire rubber, maleated polyethylene and high density polyethylene, by A R Kakroodi and D. Rodriguez, Plastics Rubber and Composites, 2013 Vol. 42, No. 3, page 115-122.
Cap Coat
1. HDPE (Nexeo, 11720 Grand Avenue, Northlake, Ill. 60164)
2. LLDPE (Nexeo)
3. Exxon Mobil Chemical Company, Vistamaxx™ (3020FL Prod pellets)
4. Struktol Co. of America, Stow, Ohio, Rubber Compatibilizer RP 28
5. Color Concentrate
Sub Layer Rubber Content
1. Lehigh Technologies micronized rubber powder at 40 mesh
2. ExxonMobil Vistamaxx (3020FL Prod pellets)
3. LLDPE Powder (Nexeo)
4. Struktol Corporation, Compatibilizer RP 28
Testing
The following blend were tested at a 50%+/−2% target focal point for rubber content and performance results based upon a 90 degree flex test.
1) 48% Lehigh Micronized Rubber: 48% Vistamaxx 3020 or equivalent: 2% Struktol Compatibilizer: 2% Color Concentrate 2) 48% Lehigh Micronized Rubber: 36.5% Vistamaxx 3020 or equivalent: 11.5% LLDPE: 2% Struktol Compatibilizer: 2% Color Concentrate 3) 48% Lehigh Micronized Rubber: 24% Vistamaxx 3020 or equivalent: 24% LLDPE: 2% Struktol Compatibilizer: 2% Color Concentrate 4) 48% Lehigh Micronized Rubber: 11.5% Vistamaxx 3020 or equivalent: 36.5% LLDPE: 2% Struktol Compatibilizer: 2% Color Concentrate *** All blends were encase in a 48/48 blend of HDPE/Vistamaxx 3020 or equivalent Cap Coat with max cap wall of 0.030″ to min wall of 0.015″, 4% blend of color concentrate and Struktol compatibilizer. Variations of Cap coating ingredients may and or will apply according to impact performance requirements and UV weathering requirements, per customer requirements or filed recommendations.
The chemical names for the above ingredients are:
Micronized Rubber=mixture of natural and synthetic rubbers, carbon black, fillers and oils; Vistamaxx=propylene-based elastomer; Compatibilizer=mixture of light color aliphatic hydrocarbon resins.
Method of Mixing Materials
The preceding material blends were measured per weight and percentage calculations using a 5000 lb Fairbanks scale for the heavier components, subtracting tare weight of the container used. The lighter components, color concentrate and compatibilizer, were measured per weight and percentage calculations on a Howe 50 lb capacity scale, subtracting tare weight of the container used. All materials were blended to a uniform blend in a 3000 lb capacity Prater Twin Auger Pulverizer/Mixer and portioned into plastic lined gaylords. Prior to line loading the main extruder, the rubber blend was processed through a Con Air Model D-100A incandescent dehumidifying drier to remove moisture.
Method of Manufacturing
Multi-layer extrusion process was used to fabricate test samples. As show in FIG. 1 , extruder B is a 62 centimeter American Maplan Twin Screw Extruder, providing an inner matrix of 48% micronized rubber, 48% Vistmaxx and 4% color concentrate/Struktol compatibilizer blend. Extruder A is a 3½ NRM Single Screw, providing an outer cap coat application of 48% HDPE, 48% Vistamaxx and 4% Color Concentrate and Struktol compatibilizer blend. Processing temperatures were set in accordance to manufacturers' specifications and output speeds. In addition, as show in FIG. 1 , the die design/extruder layout may encompass an ABA variant into the processing of a finished part where A is the same material on the outside as the inside and B is the center material of rubber blended composition. As show in FIG. 2 , an ABC layered concept may be utilized in the extrusion process, encompassing three or more extruders to provide multiple layers form inside to outside.
NTPEP Testing
The NTPEP (National Transportation Product Evaluation Program) has listed the following work plan for field testing Flexible Ground Mounted Delineator Posts.
Test Procedures:
Sample size of ten units were tested in the following way:
Eight flexible ground mounted posts were installed by the manufacturer (four installed manually and four installed mechanically). The delineators will be hit ten times (four posts for glancing bumper hits and four posts for wheel hits). A standard sedan with a bumper height of approximately 18″ while traveling at a speed of 55+/−2 mph will be used for impact testing. Five of the impacts will be at an ambient temperature of 32+/−5 degrees F. and the remaining five impacts at an ambient temperature of 85+/−5 degrees F. The test vehicle shall impact four of the posts at an angle perpendicular to the front of the posts. The same test samples will be used for the ten hits. Two flexible posts will be used for weatherometer testing. A glancing hit is defined as one on the bumper near the vehicle headlight. The delineators shall be installed a minimum of eight hours prior to being hit.
Testing Observations
The testing agent will inspect each post after each impact and document the following:
1. Any splits, cracks, breaks or other forms of deformation or distress.
2. The percent list to vertical two minutes after each impact.
3. The approximate percentage of the reflective area that is damaged after each impact to an extent it no longer performs as intended.
4. Any problems or comments associated with the installation and removal of the posts and bases. The testing agent will document any special equipment or techniques required for installing or removing the posts and bases.
It is a standard test procedure to impact the delineator at a speed of 55 MPH in an automobile at an impact height of 18″ (bumper height). The test samples using the composition of the present invention was tested in accordance with the ASTM D2444-99 Standard Test Methods for determining impact resistance on thermoplastic pipe and fittings by means of a TUP (Falling Weight).
The testing apparatus used was in conformance with the apparatus described in Paragraph 4 of the above ASTM Standard Test Method. The drop tube used in accordance with paragraph 4.3.1 was approximately 12 foot in length/height, providing for a fall of at least 11 ft. or 3.3528 meters. The TUP nose detail is shown as TUP A on page 2 of the test procedure. The mass of the TUP weight was 20 lbs.
The velocity of the impact at 57 MPH was calculated as follows:
Formula: The square root of (a+b) yields impact speed in meters per second whereas: A=Initial Speed=0 (squared) B=Height Meters×2×9.8 meter/second (squared) Note: Height=11 feet or 3.3528 meters B=3.3528 meter×2×9.8 meters squared=644 Square root of 644=25.47 MPH=(square root in meters)×2.2369 or 25.47×2.2369=56.97 MPH Impact Speed
Test Specimens
Each tube specimen generated for testing measure 6″ in length and 0.00″ in Outside Dimension. Wall thickness ranged in the 0.165″ to 0.175″.
A minimum of 20 samples were tested for preliminary tests and a minimum of 100 samples were tested at the optimum level of performance 48% Vistamaxx™.
Specimens were allowed to cool for a period of 24 hours to reach ambient room temperature before being tested. In addition, it was important to gain equal knowledge or performance upon samples that had been placed in a freezer overnight to a temperature of 20 degrees F. Upon removal from the freezer each sample was tested within 60 seconds after removal.
All test specimens including 48% rubber passed the impact TUP test at room temperature and at the 20 degree F. marker; at 120 ft/lbs using ASTM Spec D 2444-99 apparatus. No cracks observed.
Tensile Strength and Elongation
Testing
Bow Tie specimens (performance rated) were cut from extruded delineator post samples for the purpose of evaluating elasticity. Ambient room temperature samples were placed within the Tinius Olsen Locap Electromatic Compression & Tensile Testing Machine apparatus for testing and the elongation speed was set for expansion rate of 2 inches per minute. The 2 inch mark spread to 11 inches before failure and breakage occurred yielding a 1½=450% elongation.
The performance rated bow tie specimens consists of:
Inside Substrate
33% rubber—Pulverized or micronized scrap rubber
67% LDPE—Low density Polyethylene and I.E. PVC, Polyethylene, Polypropylene, ABS, metallocene. ½ pph RP28 (compatibilizer). This component permits extrusion of the rubber and permits it to adhere to another plastic.
Outside Capcoat—LDPE GA 818-073/ExxonMobil 3020FL (but will change depending on the application).
The compatibilizer used is a hydrocarbon resin offered by Struktol Company of America, 201 E. Steels Corners Road, Stow, Ohio, 44224, sold as “Struktol RP28”. The rubber is the mixture of natural and synthetic rubbers, carbon black, filler and oils called “Micronized Rubber Powder” sold by Lehigh Technologies, LLC, of 120 Royal Woods Court SW, Tucker, Ga. 30084.
This invention is illustrated by the following examples that are merely for the purpose of illustration and are not to be regarded as limiting the scope of the invention or the manner in which it can be practiced. Unless specifically indicated otherwise, parts and percentages are given by weight.
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This invention relates to rubber formulations which are useful as a structural material for utilization in manufacturing a wide variety of articles having a unique combination of rigidity, strength and flexural properties while maintaining excellent impact strength and durability. Additionally, articles made with the rubber formulations of this invention can essentially return to their original shape after being deformed by being impacted with a foreign object. A polymeric formulation which is useful as a structural material for manufacturing a wide variety of articles, said polymeric formulation being comprised of (1) about 45 weight percent to about 85 weight percent of a micronized rubber powder, (2) from about 15 weight percent to about 45 weight percent of a metallocene polyolefin elastomer, and (3) from about 1 weight percent to about 10 weight percent of a maleic anhydride grafted polyethylene.
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CROSS REFERENCE TO RELATED APPLICATIONS
This is a non-provisional application based upon U.S. provisional patent application Ser. No. 60/578,663, entitled “A METHOD AND APPARATUS FOR ADJUSTING THE RATE OF VAPORIZATION”, filed Jun. 10, 2004.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to wicked vaporization systems, and, more particularly, to wicked vaporization systems using a heating element.
2. Description of the Related Art
An electrically heated chemical delivery system, which is connectable with an electrical receptacle is known. For example, it is known to provide a housing which directly carries a pair of terminals, which extend therefrom and may be plugged into a conventional 115 volt electrical receptacle. The electrical terminals are electrically connected to a heater disposed within the body of the delivery system. A heat actuated chemical is disposed within the body and releases its gasses into the ambient environment with heat accelerating the release.
One method used to alter the amount of vaporizable material that is released in the environment is to control the air flow around the heating element. Controlling the air flow requires adjustable elements in the housing to alter the air flow that passes by the vaporizable material.
Another method of controlling the vaporization of the vaporizable material is alter the heat supplied by way of the heating element. This requires control electronics, which add substantial cost to the assembly.
What is needed in the art is a way to adjust the vaporization rate in a simple cost effective manner.
SUMMARY OF THE INVENTION
The present invention provides a vaporization system that adjusts the amount of heat applied to the vaporizable material without altering the amount of power consumed by the device.
The invention comprises, in one form thereof, a vaporization device including a housing, a wick, at least one heating element and a rotational coupling. The wick is partially contained within the housing and extends from the housing. The at least one heating element being proximate the wick. The rotational coupling interconnects the heating element with the housing.
An advantage of the present invention is that heat to the wick is adjustable without the need to alter the power supplied to the resistive heater.
Another advantage of the present invention is that the vaporization rate of liquid from the wick is adjustable with out controlling the airflow around the wick.
BRIEF DESCRIPTION OF THE DRAWINGS
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:
FIG. 1 is a side view of an embodiment of a vaporization device of the present invention; and
FIG. 2 is another side view of the vaporization device of FIG. 1 .
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one preferred 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
Referring now to the drawings, and more particularly to FIGS. 1 and 2 , there is shown a vaporization device 10 which generally includes a housing 12 having a reservoir 14 , a wick 16 and a heating block 18 carrying one or more heating elements rotatably coupled to housing 12 by way of a rotational coupling 20 . Housing 12 may include electrical contacts for an interconnection with an electrical supply that provides energy to heating block 18 . Within housing 12 is a reservoir 14 , which contains vaporizable material, which may be in the form of a fluid fragrance, an insecticide, a medicine or other material that is desirable to release in the air. The vaporizable material wicks up wick 16 from reservoir 14 and is in contact with ambient air. In order to accelerate the vaporization of the vaporizable material, heating block 18 supplies heat to wick 16 thereby increasing the vaporization of the vaporizable material supplied to wick 16 from reservoir 14 .
Heating block 18 is rotatably coupled by way of rotational coupling 20 to housing 12 . Rotational coupling 20 includes a pivot pin 20 A associated with heating block 18 and a recessed flange 20 B associated with housing 12 . Pivot pin 20 A of rotational coupling 20 is snapped into recessed flange 20 B, thereby allowing heating block 18 to be easily coupled to housing 12 . Heating block 18 may include more than one heating element, such as one located on each side of wick 16 . Heating block 18 has a heated surface or circuit that is longer than the width of wick 16 , thereby allowing heating block 18 to increase the heat transfer to wick 16 when heating block 18 is rotated as shown in FIG. 1 . When heating block 18 is rotated, as shown in FIG. 2 , the minimal amount of contact of heating block 18 with wick 16 is achieved, thereby having the lowest heat transfer from heating block 18 to wick 16 . This results in a minimal amount of vaporization of the vaporizable material from wick 16 .
Proximate to rotational coupling 20 is a stop 22 and a lowered stop 24 . When heating block 18 is rotated in direction 26 , an edge of heating block 18 contacts stop 22 , thereby increasing the contact of heating block 18 with wick 16 , which increase the heat transfer to wick 16 . When heating block 18 is rotated in direction 28 , until it encounters lowered stop 24 , then an even higher amount of heat is transferred from heating block 18 to wick 16 , since the angle of rotation in direction 28 is larger than the angle of rotation in direction 26 . The rotation of heating block 18 is about an axis, which is normal to a surface of wick 16 . Even though rotational coupling 20 is shown centrally disposed along the length of heating block 18 , rotational coupling 20 may be located at a different location along heating block 18 . As heating block 18 is rotationally displaced from the position, as shown in FIG. 2 , the heat transfer to wick 16 is increased, because a greater length of the heating elements in heating block 18 are transferring heat to wick 16 .
Both linear and non-linear heating elements are contemplated for use in vaporization device 10 in order to change the rate of increase of heat transfer to wick 16 as heating block 18 is rotated in either direction 26 or 28 .
Advantageously, the present invention alters the heat flow to wick 16 , thereby varying the temperature of wick 16 . The vaporization of chemicals that are contained in wick 16 increases with the temperature of wick 16 . The present invention simply adjusts the heat transfer by altering the contact of heating block 18 with wick 16 , rather than using another device to adjust the power supplied to a heating element. This simple solution reduces the cost involved in having an adjustable vaporization rate device as compared with other methods of adjustment.
While this invention has been described as having a preferred design, 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.
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A vaporization device including a housing, a wick, at least one heating element and a rotational coupling. The wick is partially contained within the housing and extends from the housing. The at least one heating element being proximate the wick. The rotational coupling interconnects the heating element with the housing.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] The present application is a non-provisional of, and claims the benefit of priority of U.S. Provisional Patent Application No. 61/109,881 (Attorney Docket No. 027680-001400US) filed Oct. 30, 2008; and 61/109,882 (Attorney Docket No. 027680-001500US) filed Oct. 30, 2008, the entire contents of which are incorporated herein by reference.
[0002] The present application is related to U.S. Provisional Patent Application Nos. 61/110,905; 61/115,403; 61/148,809; 61/109,973; 61/109,875; 61/109,879; 61/109,889; 61/109,893; 61/254,997; and U.S. patent application Ser. Nos. 11/747,862; 11/747,867; 12/480,929; 12/480,256; 12/483,174; 12/482,640; 12/505,326; 12/505,335; the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present application generally relates to systems and methods for creating ablation zones in human tissue. More specifically, the present application relates to the treatment of atrial fibrillation of the heart by using ultrasound energy, and even more specifically, the present application relates to ablation systems and methods used to treat atrial fibrillation that detect and compensate for collateral tissue such as the phrenic nerve, esophagus, and other tissue.
[0005] The condition of atrial fibrillation (AF) is characterized by the abnormal (usually very rapid) beating of the left atrium of the heart which is out of synch with the normal synchronous movement (‘normal sinus rhythm’) of the heart muscle. In normal sinus rhythm, the electrical impulses originate in the sino-atrial node (‘SA node’) which resides in the right atrium. The abnormal beating of the atrial heart muscle is known as ‘fibrillation’ and is caused by electrical impulses originating instead at points other than the SA node, for example, in the pulmonary veins (PV).
[0006] There are pharmacological treatments for this condition with varying degree of success. In addition, there are surgical interventions aimed at removing the aberrant electrical pathways from PV to the left atrium (‘LA’) such as the ‘Cox-Maze III Procedure’. This procedure has been shown to be 99% effective but requires special surgical skills and is time consuming. Thus, there has been considerable effort to copy the Cox-Maze procedure using a less invasive percutaneous catheter-based approach. Less invasive treatments have been developed which involve use of some form of energy to ablate (or kill) the tissue surrounding the aberrant focal point where the abnormal signals originate in PV. The most common methodology is the use of radio-frequency (‘RF’) electrical energy to heat the muscle tissue and thereby ablate it. The aberrant electrical impulses are then prevented from traveling from PV to the atrium (achieving the ‘conduction block’) and thus avoiding the fibrillation of the atrial muscle. Other energy sources, such as microwave, laser, and ultrasound have been utilized to achieve the conduction block. In addition, techniques such as cryoablation, administration of ethanol, and the like have also been used.
[0007] More recent approaches for the treatment of AF involve the use of ultrasound energy. The target tissue of the region surrounding the pulmonary vein is heated with ultrasound energy emitted by one or more ultrasound transducers.
[0008] When delivering energy to tissue, in particular when ablating tissue with ultrasound to treat atrial-fibrillation, a transmural lesion (burning all the way through the tissue) must be made to form a proper conduction block. Achieving a transmural lesion though has many challenges. Health complications may arise when esophageal or other collateral tissue such as the phrenic nerve is ablated. Thus there is a need in the medical device field to provide an ablation system and method of use that detects and compensates for collateral tissue during the ablation process. It would also be desirable to provide an ablation system that is easy to use, easy to manufacture and that is lower in cost than current commercial systems.
[0009] 2. Description of Background Art
[0010] Patents related to the treatment of atrial fibrillation include, but are not limited to the following: U.S. Pat. Nos. 6,997,925; 6,996,908; 6,966,908; 6,964,660; 6,955,173; 6,954,977; 6,953,460; 6,949,097; 6,929,639; 6,872,205; 6,814,733; 6,780,183; 6,666,858; 6,652,515; 6,635,054; 6,605,084; 6,547,788; 6,514,249; 6,502,576; 6,416,511; 6,383,151; 6,305,378; 6,254,599; 6,245,064; 6,164,283; 6,161,543; 6,117,101; 6,064,902; 6,052,576; 6,024,740; 6,012,457; 5,405,346; 5,314,466; 5,295,484; 5,246,438; and 4,641,649.
[0011] Patent Publications related to the treatment of atrial fibrillation include, but are not limited to International PCT Publication No. WO 99/02096; and U.S. Patent Publication No. 2005/0267453.
[0012] Scientific publications related to the treatment of atrial fibrillation include, but are not limited to: Haissaguerre, M. et al., Spontaneous Initiation of Atrial Fibrillation by Ectopic Beats Originating in the Pulmonary Veins, New England J Med., Vol. 339:659-666; J. L. Cox et al., The Development of the Maze Procedure for the Treatment of Atrial Fibrillation, Seminars in Thoracic & Cardiovascular Surgery, 2000; 12: 2-14; J. L. Cox et al., Electrophysiologic Basis, Surgical Development, and Clinical Results of the Maze Procedure for Atrial Flutter and Atrial Fibrillation, Advances in Cardiac Surgery, 1995; 6: 1-67; J. L. Cox et al., Modification of the Maze Procedure for Atrial Flutter and Atrial Fibrillation. II, Surgical Technique of the Maze III Procedure, Journal of Thoracic & Cardiovascular Surgery, 1995;110:485-95; J. L. Cox, N. Ad, T. Palazzo, et al. Current Status of the Maze Procedure for the Treatment of Atrial Fibrillation, Seminars in Thoracic & Cardiovascular Surgery, 2000; 12: 15-19; M. Levinson, Endocardial Microwave Ablation: A New Surgical Approach for Atrial Fibrillation; The Heart Surgery Forum, 2006; Maessen et al., Beating Heart Surgical Treatment of Atrial Fibrillation with Microwave Ablation, Ann Thorac Surg 74: 1160-8, 2002; A. M. Gillinov, E. H. Blackstone and P. M. McCarthy, Atrial Fibrillation: Current Surgical Options and their Assessment, Annals of Thoracic Surgery 2002;74:2210-7; Sueda T., Nagata H., Orihashi K., et al., Efficacy of a Simple Left Atrial Procedure for Chronic Atrial Fibrillation in Mitral Valve Operations, Ann Thorac Surg 1997;63:1070-1075; Sueda T., Nagata H., Shikata H., et al.; Simple Left Atrial Procedure for Chronic Atrial Fibrillation Associated with Mitral Valve Disease, Ann Thorac Surg 1996;62:1796-1800; Nathan H., Eliakim M., The Junction Between the Left Atrium and the Pulmonary Veins, An Anatomic Study of Human Hearts, Circulation 1966;34:412-422; Cox J. L., Schuessler R. B., Boineau J. P., The Development of the Maze Procedure for the Treatment of Atrial Fibrillation, Semin Thorac Cardiovasc Surg 2000;12:2-14; and Gentry et al., Integrated Catheter for 3- D Intracardiac Echocardiography and Ultrasound Ablation, IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, Vol. 51, No. 7, pp 799-807.
BRIEF SUMMARY OF THE INVENTION
[0013] The present application generally relates to systems and methods for creating ablation zones in human tissue. More specifically, the present application relates to the treatment of atrial fibrillation of the heart by using ultrasound energy, and even more specifically, the present application relates to ablation systems and methods used to treat atrial fibrillation that detect and compensate for collateral tissue such as the esophagus, phrenic nerve, and other tissue.
[0014] In a first aspect of the present invention a tissue ablation method for treating atrial fibrillation in a patient comprises locating an ostium of a pulmonary vein, and positioning an interventional catheter adjacent the ostium. The interventional catheter has an energy source. Collateral tissue adjacent the ostium is identified and tissue around the ostium is transmurally ablated with energy from the energy source. This forms a contiguous transmural lesion circumscribing the ostium and the lesion blocks aberrant electrical pathways in the tissue so as to reduce or eliminate the atrial fibrillation. The ablating is modified so as to avoid ablating or otherwise damaging the collateral tissue.
[0015] The interventional catheter may further comprise a sensor adjacent the energy source. The locating step may comprise delivering energy from the energy source toward the tissue adjacent the ostium, and sensing energy reflected from the tissue adjacent the ostium with the sensor. The sensor may comprise at least a portion of the energy source.
[0016] The positioning step may comprise intravascularly advancing the interventional catheter into a left atrium of the patient's heart. Identifying may comprise characterizing properties of the tissue adjacent the ostium and comparing the properties with known tissue properties. Identifying may be a part of a diagnostic sweep of tissue adjacent the ostium. The sweep may be a systematic scan to acquire information about the tissue adjacent the ostium. The identifying step may be performed while the ablating step is performed.
[0017] The modifying may comprise modifying the transmural lesion so as to avoid the collateral tissue. Modifying may comprise changing an originally planned transmural lesion path to a new transmural lesion path or modifying may comprise changing the energy emitted from the energy source so as to avoid damaging the collateral tissue.
[0018] The collateral tissue may comprise an esophagus. Identifying the esophagus may comprise positioning an esophageal detection device into the esophagus. Identifying may also comprise sensing the presence of the detection device through one or more layers of tissue. The esophageal detection device may comprise a balloon catheter which may be filled with a fluid such as saline, water, gas (e.g. carbon dioxide, air). Liquids such as saline or water are preferably filled with microbubbles to enhance echogenicity. The method may further comprise sensing water in the balloon catheter with an ultrasound signal delivered by the energy source. The esophageal detection device may also comprise a transponder such as a reflective material, a chemical substance, RFID tag, a capacitive plate, an inductive component, an ultrasound transducer, and an infrared light. The esophageal detection device may further protect the esophagus by cooling the esophagus. Identifying the esophagus may comprise sensing the esophageal detection device with the interventional catheter.
[0019] The collateral tissue may also comprise a phrenic nerve. Identifying the nerve may comprise applying pressure or an electrical signal to the phrenic nerve and monitoring the patient for a reflex response. The reflex response may comprise a hiccup. Monitoring may comprise audibly monitoring the patient. Applying pressure may comprise directing an ultrasound pressure wave to the phrenic nerve, pushing on the nerve with an instrument or electrically stimulating the nerve.
[0020] In another aspect of the present invention, a tissue ablation system for treating atrial fibrillation in a patient comprises an interventional catheter having an energy source and a sensor. The energy source is adapted to deliver a beam of energy to tissue thereby ablating tissue around an ostium of a pulmonary vein to form a contiguous lesion circumscribing the ostium. The contiguous lesion blocks aberrant electrical pathways in the tissue so as to reduce or eliminate the atrial fibrillation. The system also includes an esophageal detection device positionable in the esophagus. The detection device has a transponder detectable by the sensor through one or more layers of tissue.
[0021] The detection device may comprise a balloon catheter and the balloon catheter may be at least partially filled with a fluid such as saline, water, gas (e.g. carbon dioxide, air). Liquids such as saline or water are preferably filled with microbubbles to enhance echogenicity. The beam of energy may comprise an ultrasound signal that reflects off the saline or water filled portion of the balloon catheter and is sensed by the sensor. The transponder may comprise one of a reflective material, a chemical substance, RFID tag, a capacitive plate, an inductive component, an ultrasound transducer and an infrared light. The energy source may comprise an ultrasound transducer, and the sensor may comprise at least a portion of the ultrasound transducer.
[0022] These and other embodiments are described in further detail in the following description related to the appended drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 illustrates an exemplary embodiment of an energy delivery device.
[0024] FIG. 2 illustrates exemplary use of the energy delivery device in FIG. 1 to ablate cardiac tissue.
[0025] FIG. 3 illustrates an exemplary embodiment of the energy source and backing.
[0026] FIGS. 4A-4B illustrate alternative embodiments of an energy source.
[0027] FIGS. 5-6 illustrate still other embodiments of an energy source.
[0028] FIGS. 7-10 illustrate the energy beam and zone of ablation in tissue.
[0029] FIG. 11 shows a flowchart of an exemplary method of collateral tissue compensation.
[0030] FIG. 12 shows a flowchart of an exemplary method of identifying the phrenic nerve.
[0031] FIG. 13 shows a flowchart of an exemplary method of identifying the location of the esophagus.
[0032] FIG. 14 illustrates an exemplary embodiment of an esophageal catheter.
[0033] FIG. 15 illustrates insertion of a detection device in the esophagus.
[0034] FIGS. 16A-16B illustrate location of the phrenic nerve.
DETAILED DESCRIPTION OF THE INVENTION
[0035] The following description of the preferred embodiments of the invention is not intended to limit the invention to these preferred embodiments, but rather to enable any person skilled in the art to make and use this invention.
[0036] As shown in FIG. 1 , the energy delivery system 10 of the preferred embodiments includes an energy source 12 , that functions to provide a source of ablation energy, and an electrical attachment 14 , coupled to the energy source 12 , that functions to energize the energy source 12 such that it emits an energy beam 20 . The energy delivery system 10 of the preferred embodiments also includes a sensor 40 or the energy source 12 may also serve as the sensor to detect the gap (distance of the tissue surface from the energy source 12 ), the thickness of the tissue targeted for ablation, the characteristics of the ablated tissue, and any other suitable parameter or characteristic of the tissue and/or the environment around the energy delivery system 10 . The energy delivery system 10 of the preferred embodiments also includes a processor 33 operatively coupled to the sensor and to the electrical attachment 14 , that controls the electrical attachment 14 and/or the electrical signal delivered to the energy source 12 based on the information from the sensor 40 . The energy delivery system 10 is preferably designed for delivering energy to tissue, more specifically, for delivering ablation energy to tissue, such as heart tissue, to create a conduction block—isolation and/or block of conduction pathways of abnormal electrical activity, which typically originate from the pulmonary veins in the left atrium—for treatment of atrial fibrillation in a patient. The system 10 , however, may be alternatively used with any suitable tissue in any suitable environment and for any suitable reason.
[0037] 1. The Energy Source. As shown in FIG. 1 , the energy source 12 of the preferred embodiments functions to provide a source of ablation energy and emit an energy beam 20 . The energy source 12 is preferably moved and positioned within a patient, preferably within the left atrium of the heart of the patient, such that the energy source 12 is positioned at an appropriate angle with respect to the target tissue. The angle is preferably any suitable angle such that the emitted energy beam 20 propagates into the target tissue, and preferably generates a transmural lesion (i.e. a lesion through the thickness of the tissue that preferably creates a conduction block, as described below). Angles between 40 and 140 degrees are preferable because in this range the majority of the energy beam will preferably propagate into the tissue and the lesion depth needed to achieve transmurality is preferably minimally increased from the ideal orthogonal angle.
[0038] As shown in FIG. 1 , the energy source 12 is preferably coupled to a housing 16 . The energy source 12 and the housing 16 are preferably positionable within the patient. For example, the housing 16 , and the energy source 12 within it, are preferably moved to within the left atrium of the heart (or in any other suitable location) and, once positioned there, are preferably moved to direct the energy source 12 and the emitted energy beam 20 towards the target tissue at an appropriate angle. Furthermore, the housing 16 , and the energy source 12 within it, are preferably moved along an ablation path such that the energy source 12 provides a partial or complete zone of ablation along the ablation path. The zone of ablation along the ablation path preferably has any suitable geometry to provide therapy, such as providing a conduction block for treatment of atrial fibrillation in a patient. The zone of ablation along the ablation path may alternatively provide any other suitable therapy for a patient. A linear ablation path is preferably created by moving the housing 16 , and the energy source 12 within it, along an X, Y, and/or Z-axis. As shown in FIG. 2 , the motion of the distal portion of the elongate member 18 in and out of the guide sheath portion GS of the elongate member 18 is represented by the z-axis. A generally circular or elliptical ablation path is preferably created by rotating the energy source 12 about an axis (for example, as defined by the wires W in FIG. 2 ). The elongate member 18 , along with the housing 16 and the energy source 12 , is preferably rotated, as shown in FIG. 2 . Alternatively, in other configurations, the energy source 12 is rotated within the housing 16 . For example, as shown in FIG. 2 , the housing 16 points towards the wall tissue 2174 of an atrium. The energy source 12 in the housing 16 emits an energy beam to establish an ablation window 2172 . As the housing 16 (and an elongate member 18 , described below) are rotated (as shown by arrow 2124 in FIG. 2 ), the ablation window 2172 sweeps a generally circular ablation path 2176 creating a section of a conical shell. Further, in this example, it may be desirable to move the elongate member forwards or backwards along the Z-axis to adjust for possible variations in the anatomy. Although the ablation path is preferably linear or circular, any suitable ablation path may be created by any suitable combination of movement in the X, Y, and Z axes and rotational movement.
[0039] As shown in FIG. 1 , the energy delivery system 10 of the preferred embodiments may also include an elongate member 18 , coupled to the energy source 12 . The elongate member 18 is preferably a catheter made of a flexible multi-lumen tube, but may alternatively be a cannula, tube or any other suitable elongate structure having one or more lumens. The elongate member 18 of the preferred embodiments functions to accommodate pull wires, fluids, gases, energy delivery structures, electrical wires, therapy catheters, navigation catheters, pacing catheters, connections and/or any other suitable device or element. As shown in FIG. 1 , the elongate member 18 preferably includes a housing 16 positioned at a distal portion of the elongate member 18 . The elongate member 18 further functions to move and position the energy source 12 and/or the housing 16 within a patient, such that the emitted energy beam 20 propagates into the target tissue at an appropriate angle and the energy source 12 and/or the housing 16 is moved along an ablation path such that the energy source 12 provides a partial or complete zone of ablation along the ablation path.
[0040] The energy source 12 is preferably an ultrasound transducer that emits an ultrasound beam, but may alternatively be any suitable energy source that functions to provide a source of ablation energy. Suitable sources of ablation energy include but are not limited to, radio frequency (RF) energy, microwaves, photonic energy, and thermal energy. The therapy could alternatively be achieved using cooled sources (e.g., cryogenic fluid). The energy delivery system 10 preferably includes a single energy source 12 , but may alternatively include any suitable number of energy sources 12 . The ultrasound transducer is preferably made of a piezoelectric material such as PZT (lead zirconate titanate) or PVDF (polyvinylidine difluoride), or any other suitable ultrasound emitting material. For simplicity, the front face of the transducer is preferably flat, but may alternatively have more complex geometry such as either concave or convex to achieve an effect of a lens or to assist in apodization—selectively decreasing the vibration of a portion or portions of the surface of the transducer—and management of the propagation of the energy beam 20 . The transducer preferably has a circular geometry, but may alternatively be elliptical, polygonal, or any other suitable shape. The transducer may further include coating layers which are preferably thin layer(s) of a suitable material. Some suitable transducer coating materials may include graphite, metal-filled graphite, gold, stainless steel, magnesium, nickel-cadmium, silver, and a metal alloy. For example, as shown in FIG. 1 , the front face of the energy source 12 is preferably coupled to one or more matching layers 34 . The matching layer(s) preferably functions to increase the efficiency of coupling of the energy beam 20 into the surrounding fluid 28 . The matching layer 34 is preferably made from a plastic such as parylene, preferably placed on the transducer face by a vapor deposition technique, but may alternatively be any suitable material, such as graphite, metal-filled graphite, metals, or ceramic, added to the transducer in any suitable manner.
[0041] The energy source 12 is preferably one of several variations. In a first variation, as shown in FIG. 3 , the energy source 12 is a disc with a flat front surface coupled to a backing 22 with an adhesive ring 24 . The backing 22 forms a pocket 26 to help reflect energy in a desired direction, often distally away from the housing 16 into the treatment tissue. A plurality of axial channel or grooves 36 along the backing allow fluid to flow therepast in order to help cool the transducer 12 and prevent direct tissue contact. In a second variation, as shown in FIGS. 4A and 4B , the energy source 12 ′ includes an inactive portion 42 . In this variation, the inactive portion 42 does not emit an energy beam when the energy source 12 is energized, or may alternatively emit an energy beam with a very low (substantially zero) energy. The inactive portion 42 preferably functions to aid in the temperature regulation of the energy source, i.e. preventing the energy source from becoming too hot. In a full disk transducer, as shown in FIG. 3 , the center portion of the transducer generally becomes the hottest portion of the transducer while energized. By removing the center portion or a portion of the center portion of the transducer, the energy emitted from the transducer is preferably distributed differently across the transducer, and the heat of the transducer is preferably more easily dissipated.
[0042] The inactive portion 42 is preferably a hole or gap defined by the energy source 12 ′. In this variation, a coolant source may be coupled to, or in the case of a coolant fluid, it may flow through the hole or gap defined by the energy source 12 ′ to further cool and regulate the temperature of the energy source 12 ′. The inactive portion 42 may alternatively be made of a material with different material properties from that of the energy source 12 ′. For example, the material is preferably a metal, such as copper, which functions to draw or conduct heat away from the energy source 12 . Alternatively, the inactive portion is made from the same material as the energy source 12 , but with the electrode plating removed or disconnected from the electrical attachments 14 and or the generator. The inactive portion 42 is preferably disposed along the full thickness of the energy source 12 ′, but may alternatively be a layer of material on or within the energy source 12 ′ that has a thickness less than the full thickness of the energy source 12 ′. As shown in FIG. 4A , the energy source 12 ′ is preferably a doughnut-shaped transducer. As shown, the transducer preferably defines a hole (or inactive portion 42 ) in the center portion of the transducer. The energy source 12 ′ of this variation preferably has a circular geometry, but may alternatively be elliptical, polygonal as shown in FIG. 4B ), or any other suitable shape. The energy source 12 ′ preferably includes a singular, circular inactive portion 42 , but may alternatively include any suitable number of inactive portions 42 of any suitable geometry, as shown in FIG. 4B . The total energy emitted from the energy source 12 is related to the surface area of the energy source 12 that is active (i.e. emits energy beam 20 ). Therefore, the size and location of inactive portion(s) 42 preferably sufficiently reduce the heat build-up in the energy source 12 , while allowing the energy source 12 to provide as much output energy as possible or as desired.
[0043] In a third variation, as shown in FIG. 5 , the energy source 12 ″ preferably includes a plurality of annular transducers 44 . The plurality of annular transducers is preferably a plurality concentric rings, but may alternatively have any suitable configuration with any suitable geometry, such as elliptical or polygonal. The energy source 12 ″ may further include an inactive portion 42 , such as the center portion of the energy source 12 ″ as shown in FIG. 5 . The plurality of annular transducers 44 preferably includes at least a first annular transducer and a second annular transducer. The first annular transducer preferably has material properties that differ from those of the second annular transducer, such that the first annular transducer emits a first energy beam that is different from the second energy beam emitted from the second annular ring. Furthermore, the first annular transducer may be energized with a different frequency, voltage, duty cycle, power, and/or for a different length of time from the second annular transducer. Alternatively the first annular ring may be operated in a different mode from the second annular ring. For example, the first annular ring may be run in a therapy mode, such as ablate mode which delivers a pulse of ultrasound sufficient for heating of the tissue, while the second annular ring may be run in a diagnostic mode, such as A-mode, which delivers a pulse of ultrasound of short duration, which is generally not sufficient for heating of the tissue but functions to detect characteristics of the target tissue and/or environment in and around the energy delivery system. The first annular transducer may further include a separate electrical attachment 14 from that of the second annular transducer.
[0044] In a fourth variation, as shown in FIG. 6 , the energy source 12 ′″ preferably includes a grid of transducer portions 46 . The grid of transducer portions 46 preferably has any suitable geometry such as circular, rectangular (as shown in FIG. 6 ), elliptical, polygonal, or any other suitable geometry. The energy source 12 ′″ in this variation may further include a transducer portion that is inactive, such as an inactive portion as described in the second variation of the energy source 12 ′. The grid of transducer portions 46 preferably includes at least a first transducer portion and a second transducer portion. In a first version, the first transducer portion and the second transducer portion are preferably portions of a single transducer with a single set of material properties. The first transducer portion is preferably energized with a different frequency, voltage, duty cycle, power, and/or for a different length of time from the second transducer portion. Furthermore the first transducer portion may be operated in a different mode from the second transducer portion. For example, the first transducer portion may operate in a therapy mode, such as ablate mode, while the second transducer portion may operate in a diagnostic mode, such as A-mode. In this version, the first transducer portion may further include a separate electrical attachment 14 from that of the second transducer portion. For example, the first transducer portion may be located towards the center of the energy source 12 ′″ and the second transducer portion may be located towards the outer portion of the energy source 12 ′″ and the second transducer portion may be energized while the first transducer portion remains inactive. In a second version, the first transducer portion preferably has material properties that differ from those of the second transducer portion, such that the first transducer portion emits a first energy beam that is different from the second energy beam emitted from the second portion. In this version, the first transducer portion may also be energized with a different frequency, voltage, duty cycle, power, and/or for a different length of time from the second transducer portion.
[0045] 2. The Electrical Attachment. As shown in FIG. 1 , the electrical attachment 14 of the preferred embodiments functions to energize the energy source 12 such that it emits an energy beam 20 . In use, as the energy source 12 is energized, it emits an energy beam 20 towards targeted tissue. As the energy is transferred from the energy beam 20 into the tissue, the targeted tissue portion is preferably heated sufficiently to achieve ablation. As shown in FIG. 1 , the electrical attachment 14 is preferably coupled to the energy source 12 . The energy delivery system 10 preferably includes two electrical attachments 14 and 14 ′, but may alternatively include any suitable number of electrical attachments to energize the energy source 12 . The energy source 12 preferably has a first electrical attachment 14 coupled the front surface of the energy source 12 which is coupled to a suitably insulated wire 38 . The electrical attachment 14 is preferably accomplished by standard bonding techniques such as soldering, wire bonding, conductive epoxy, or swaging. The electrical attachment 14 is preferably placed closer to the edge of the energy source 12 so as not to disturb the energy beam 20 emitted by the energy source 12 upon being electrically energized. The energy source 12 preferably has a second electrical attachment 14 ′ coupled the back surface of the energy source 12 which is coupled to a suitably insulated wire 38 ′. Wires 38 and 38 ′ together form a pair 38 ″, which are preferably a twisted shielded pair, a miniature coaxial cable, a metal tube braid, or are coupled in any other suitable method. The electrical attachment(s) 14 may alternatively be coupled to the energy source 12 in any other suitable fashion in any other suitable configuration.
[0046] The energy delivery system 10 of the preferred embodiments also includes an electrical generator (not shown) that functions to provide power to the energy source 12 via the electrical attachment(s) 14 . The energy source 12 is preferably coupled to the electrical generator by means of the suitably insulated wires 38 and 38 ′ connected to the electrical attachments 14 and 14 ′ coupled to the two faces of the energy source 12 . When energized by the generator the energy source 12 emits energy. The generator provides an appropriate signal to the energy source 12 to create the desired energy beam 20 . The frequency is preferably in the range of 5 to 25 MHz, more preferably in the range of 8 to 20 MHz, and even more preferably in the range of 2 to 15 MHz. The energy of the energy beam 20 is determined by the excitation voltage applied to the energy source 12 , the duty cycle, and the total time the voltage is applied. The voltage is preferably in the range of 5 to 200 volts peak-to-peak. In addition, a variable duty cycle is preferably used to control the average power delivered to the energy source 12 . The duty cycle preferably ranges from 0% to 100%, with a repetition frequency that is preferably faster than the time constant of thermal conduction in the tissue. One such appropriate repetition frequency is approximately 40 kHz.
[0047] 3. Energy Beam and Tissue Interaction. When energized with an electrical signal or pulse train by the electrical attachment 14 and/or 14 ′, the energy source 12 emits an energy beam 20 (such as a sound pressure wave). The properties of the energy beam 20 are determined by the characteristics of the energy source 12 , the matching layer 34 , the backing 22 (described below), the electrical signal from electrical attachment 14 . These elements determine the frequency, bandwidth, and amplitude of the energy beam 20 (such as a sound wave) propagated into the tissue. As shown in FIG. 7 , the energy source 12 emits energy beam 20 such that it interacts with tissue 276 and forms a lesion (zone of ablation 278 ). The energy beam 20 is preferably an ultrasound beam. The tissue 276 is preferably presented to the energy beam 20 within the collimated length L. The front surface 280 of the tissue 276 is at a distance d ( 282 ) away from the distal face of the housing 16 . As the energy beam 20 travels through the tissue 276 , its energy is absorbed and scattered by the tissue 276 and most of the ablation energy is converted to thermal energy. This thermal energy heats the tissue to temperatures higher than the surrounding tissue resulting in a heated zone 278 . In the zone 278 where the tissue is heated, the tissue cells are preferably rendered dead due to heat. The temperatures of the tissue are preferably above the temperature where cell death occurs in the heated zone 278 and therefore, the tissue is said to be ablated. Hence, the zone 278 is preferably referenced as the ablation zone or lesion.
[0048] 4. The Physical Characteristics of the Lesion. The shape of the lesion or ablation zone 278 formed by the energy beam 20 depends on the characteristics of suitable combination factors such as the energy beam 20 , the energy source 12 (including the material, the geometry, the portions of the energy source 12 that are energized and/or not energized, etc.), the matching layer 34 , the backing 22 (described below), the electrical signal from electrical attachment 14 (including the frequency, the voltage, the duty cycle, the length and shape of the signal, etc.), and the characteristics of target tissue that the beam 20 propagates into and the length of contact or dwell time. The characteristics of the target tissue include the thermal transfer properties and the ultrasound absorption, attenuation, and backscatter properties of the target tissue and surrounding tissue.
[0049] The shape of the lesion or ablation zone 278 formed by the energy beam 20 is preferably one of several variations due to the energy source 12 (including the material, the geometry, the portions of the energy source 12 that are energized and/or not energized, etc.). In a first variation of the ablation zone 278 , as shown in FIG. 7 , the energy source 12 is a full disk transducer and the ablation zone 278 is a tear-shaped lesion. The diameter D 1 of the zone 278 is smaller than the diameter D of the beam 20 at the tissue surface 280 and further, the outer layer(s) of tissue 276 preferably remain substantially undamaged. This is due to the thermal cooling provided by the surrounding fluid (cooling fluid and/or blood), which is flowing past the tissue surface 280 . More or less of the outer layers of tissue 276 may be spared or may remain substantially undamaged due to the amount that the tissue surface 280 is cooled and/or the characteristics of the energy delivery system 10 (including the energy source 12 and the energy beam 20 ). The energy deposited in the ablation zone 278 preferably interacts with the non-surface layer(s) of tissue such that the endocardial surface remains pristine (and/or not charred). As the energy beam 20 travels deeper into the tissue, the thermal cooling is provided by the surrounding tissue, which is not as efficient as that on the surface. The result is that the ablation zone 278 has a larger diameter D 2 than D 1 as determined by the heat transfer characteristics of the surrounding tissue as well as the continued input of the energy from the beam 20 . As the beam 20 is presented to the tissue for an extended period of time, the ablation zone 278 extends into the tissue, but not indefinitely. There is a natural limit of the depth 288 of the ablation zone 278 as determined by the factors such as the attenuation and absorption of the ultrasound energy as the energy beam 20 propagates into the tissue, heat transfer provided by the healthy surrounding tissue, and the divergence of the beam beyond the collimated length L. During this ultrasound-tissue interaction, the ultrasound energy is being absorbed by the tissue, and therefore less and less of it is available to travel further into the tissue. Thus a correspondingly smaller diameter heated zone is developed in the tissue, and the overall result is the formation of the heated ablation zone 278 , which is in the shape of an elongated tear limited to a depth 288 into the tissue.
[0050] In a second variation, as shown in FIG. 9 , the ablation zone 278 ′ has a shorter depth 288 ′. In this variation, the lesion preferably has a more blunt shape than ablation zone 278 ( FIG. 7 ). One possible lesion geometry of this second variation may be a tooth shaped geometry, as shown in FIG. 9 , but may alternatively have any suitable shape such as a blunt tear shape, a circular shape, or an elliptical shape. As shown in FIG. 9 , zone 278 ′ (similarly to zone 278 in FIG. 7 ) has a diameter D 1 of the zone 278 ′ smaller than the diameter D of the beam 20 at the tissue surface 280 due to the thermal cooling provided by the surrounding fluid flowing past the tissue surface 280 . In this variation, the energy source 12 ′ preferably has an inactive portion 42 located at the center of the energy source 12 ′, such that energy source is a doughnut-shaped transducer which emits an energy beam 20 that is generally more diffused, with a broader, flatter profile, than the energy beam 20 of the first variation ( FIG. 7 ). The energy beam 20 emitted from the doughnut-shaped transducer, as shown in FIG. 9 , preferably has a reduced peak intensity along the midline of the energy beam (as shown in cross section by the dotted lines in FIG. 9 ). With this ultrasound-tissue interaction, the reduced peak intensity along the midline of the energy beam is being absorbed by the tissue, and less and less of the energy is available to travel further into the tissue, forming a blunter lesion than in the first variation.
[0051] The size and characteristics of the ablation zone also depend on the frequency and voltage applied to the energy source 12 to create the desired energy beam 20 . For example, as the frequency increases, the depth of penetration of ultrasound energy into the tissue is reduced resulting in an ablation zone 278 (ref. FIG. 7 ) of shallower depth 288 . The frequency is preferably in the range of 5 to 25 MHz, more preferably in the range from 8 to 20 MHz, and even more preferably in the range from 10 to 18 MHz. The energy of the energy beam 20 is determined by the excitation voltage applied to the energy source 12 for a transducer fabricated from PZT material, for example. The voltage is preferably in the range of 5 to 200 volts peak-to-peak. In addition, a variable duty cycle is preferably used to control the average power delivered to the energy source 12 . The duty cycle preferably ranges from 0% to 100%, with a repetition frequency of approximately 40 kHz, which is preferably faster than the time constant of thermal conduction in the tissue. This results in an ablation zone 278 , which is created within 1 to 5 seconds, and is of depth 288 of approximately 5 millimeters (mm), and of a maximum diameter of approximately 2.5 mm in correspondence to the diameter of the energy source 12 , for an average power level preferably 0.5 to 25 watts, more preferably 2 to 10 watts, and even more preferably 2 to 7 watts.
[0052] The size and characteristics of the ablation zone 278 also depend on the time the targeted tissue is contacted by the energy beam 20 , as shown in FIGS. 8A-8D , which exemplify the formation of the lesion at times t 1 , t 2 , t 3 and t 4 , respectively. The ablation zone 278 in the tissue is formed by the conversion of the ultrasound energy to thermal energy in the tissue. As the energy beam 20 initially impinges on the front surface 280 of the tissue 276 at time t 1 , heat is created which begins to form the lesion 278 ( FIG. 8A ). As time passes on to t 2 , and t 3 ( FIGS. 8B and 8C ), the ablation zone 278 continues to grow in diameter and depth. This time sequence from t 1 to t 3 preferably takes as little as 1 to 5 seconds, depending on the ultrasound energy density. As the incidence of the ultrasound beam is continued beyond time t 3 , the ablation lesion 278 grows slightly in diameter and length, and then stops growing due to the steady state achieved in the energy transfer from its ultrasound form to the thermal form balanced by the dissipation of the thermal energy into the surrounding tissue. The example shown in FIG. 8D shows the lesion after an exposure t 4 of approximately 30 seconds to the energy beam 20 . Thus the lesion reaches a natural limit in size and does not grow indefinitely.
[0053] The ultrasound energy density preferably determines the speed at which the ablation occurs. The acoustic power delivered by the energy source 12 divided by the cross sectional area of the beam 20 determines the energy density per unit time. Effective acoustic power preferably ranges from 0.5 to 25 watts, more preferably from 2 to 10 watts, and even more preferably from 2 to 7 watts, and the corresponding power densities preferably range from 50 watts/cm 2 to 2500 watts/cm 2 . These power densities are developed in the ablation zone. As the beam diverges beyond the ablation zone, the power density falls such that ablation will not occur, regardless of the time exposure.
[0054] Although the shape of the ablation zone 278 is preferably one of several variations, the shape of the ablation zone 278 may be any suitable shape and may be altered in any suitable fashion due to any suitable combination of the energy beam 20 , the energy source 12 (including the material, the geometry, etc.), the matching layer 34 , the backing 22 (described below), the electrical signal from electrical attachment 14 (including the frequency, the voltage, the duty cycle, the length of the pulse, etc.), and the target tissue the beam 20 propagates into and the length of contact or dwell time.
[0055] 5. The Sensor. The energy delivery system 10 of the preferred embodiments also includes a sensor separate from the energy source and/or the energy source 12 may further function as a sensor to detect the gap (the distance of the tissue surface from the energy source 12 ), the thickness of the tissue targeted for ablation, the characteristics of the ablated tissue, the incident beam angle, and any other suitable parameter or characteristic of the tissue and/or the environment around the energy delivery system 10 , such as the temperature. By detecting the information, the sensor (coupled to the processor, as described below) preferably functions to guide the therapy provided by the ablation of the tissue.
[0056] The sensor is preferably one of several variations. In a first variation, the sensor is preferably an ultrasound transducer that functions to detect information with respect to the gap, the thickness of the tissue targeted for ablation, the characteristics of the ablated tissue, and any other suitable parameter or characteristic. The sensor preferably has a substantially identical geometry as the energy source 12 to insure that the area diagnosed by the sensor is substantially identical to the area to be treated by the energy source 12 . More preferably, the sensor is the same transducer as the transducer of the energy source, wherein the energy source 12 further functions to detect information by operating in a different mode (such as A-mode, defined below).
[0057] The sensor of the first variation preferably utilizes a burst of ultrasound of short duration, which is generally not sufficient for heating of the tissue. This is a simple ultrasound imaging technique, referred to in the art as A Mode, or Amplitude Mode imaging. As shown in FIG. 10 , sensor 40 preferably sends a burst 290 of ultrasound towards the tissue 276 . A portion of the beam is reflected and/or backscattered as 292 from the front surface 280 of the tissue 276 . This returning sound wave 292 is detected by the sensor 40 a short time later and converted to an electrical signal, which is sent to the electrical receiver (not shown). The returning sound wave 292 is delayed by the amount of time it takes for the sound to travel from the sensor 40 to the front boundary 280 of the tissue 276 and back to the sensor 40 . This travel time represents a delay in receiving the electrical signal from the sensor 40 . Based on the speed of sound in the intervening media (fluid 286 and blood 284 ), information regarding the gap distance d ( 282 ) is detected. As the sound beam travels further into the tissue 276 , a portion 293 of it is scattered from the lesion 278 being formed and travels towards the sensor 40 . Again, the sensor 40 converts this sound energy into electrical signals and a processor (described below) converts this information into characteristics of the lesion formation such as thickness, etc. As the sound beam travels still further into the tissue 276 , a portion 294 of it is reflected from the back surface 298 and travels towards the transducer. Again, the sensor 40 converts this sound energy into electrical signals and the processor converts this information into the thickness t ( 300 ) of the tissue 276 at the point of the incidence of the ultrasound burst 290 . As the catheter housing 16 is traversed in a manner 301 across the tissue 276 , the sensor 40 detects the gap distance d ( 282 ), lesion characteristics, and the tissue thickness t ( 300 ). The sensor preferably detects these parameters continuously, but may alternatively detect them periodically or in any other suitable fashion. This information is used to manage the delivery of continuous ablation of the tissue 276 during therapy as discussed below.
[0058] In a second variation, the sensor is a temperature sensor that functions to detect the temperature of the target tissue, the surrounding environment, the energy source 12 , the coolant fluid as described below, and/or the temperature of any other suitable element or area. The temperature senor is preferably a thermocouple, but may alternatively be any suitable temperature sensor, such as a thermistor or an infrared temperature sensor. This temperature information gathered by the sensor is preferably used to manage the delivery of continuous ablation of the tissue 276 during therapy and to manage the temperature of the target tissue and/or the energy delivery system 10 as discussed below.
[0059] 6. The Processor. The energy delivery system 10 of the preferred embodiments also includes a processor 33 (illustrated in FIG. 1 ), coupled to the sensor 40 and to the electrical attachment 14 , that controls the electrical attachment 14 and/or the electrical signal delivered to the electrical attachment 14 based on the information from the sensor 40 . The processor 33 is preferably a conventional processor, but may alternatively be any suitable device to perform the desired functions.
[0060] The processor 33 preferably receives information from the sensor such as information related to the gap distance, the thickness of the tissue targeted for ablation, the characteristics of the ablated tissue, and any other suitable parameter or characteristic. Based on this information, the processor preferably controls the energy beam 20 emitted from the energy source 12 by modifying the electrical signal sent to the energy source 12 via the electrical attachment 14 such as the frequency, the voltage, the duty cycle, the length of the pulse, and/or any other suitable parameter. The processor preferably also controls the energy beam 20 by controlling portions of the energy source 12 that are energized using various frequencies, voltages, duty cycles, etc. Different portions of the energy source 12 may be energized as described above with respect to the plurality of annular transducers 44 and the grid of transducer portions 46 of the energy source 12 ″ and 12 ′″ respectively. Additionally, the processor may further be coupled to a fluid flow controller. The processor preferably controls the fluid flow controller to increase or decrease fluid flow based on the sensor detecting characteristics of the ablated tissue, of the unablated or target tissue, the temperature of the tissue and/or energy source, and/or the characteristics of any other suitable condition.
[0061] By controlling the energy beam 20 (and/or the cooling of the targeted tissue or energy source 12 ), the shape of the ablation zone 278 is controlled. For example, the depth 288 of the ablation zone is preferably controlled such that a transmural lesion (a lesion through the thickness of the tissue) is achieved. Additionally, the processor preferably functions to minimize the possibility of creating a lesion beyond the targeted tissue, for example, beyond the outer atrial wall. If the sensor detects the lesion and/or the ablation window 2172 (as shown in FIG. 2 ) extending beyond the outer wall of the atrium or that the depth of the lesion has reached or exceeded a preset depth, the processor preferably turns off the generator and/or ceases to send electrical signals to the electrical attachment(s) 14 .
[0062] Additionally, the processor preferably functions to maintain a preferred gap distance between the energy source and the tissue to be treated. The gap distance is preferably between 0 mm and 30 mm, more preferably between 1 mm and 20 mm. If the sensor detects the lesion and/or the ablation window 2172 (as shown in FIG. 2 ) extending beyond the outer wall of the atrium or if it does not reach the outer wall of the atrium, or that the depth of the lesion has either not reached or has exceeded a preset depth, the processor preferably repositions the energy delivery system. For example, as the housing 16 (and an elongate member 18 , described below) are rotated (as shown by arrow 2124 in FIG. 2 ), the ablation window 2172 preferably sweeps a generally circular ablation path 2176 creating a section of a conical shell. However, if the sensor determines that the ablation window 2172 is not reaching the wall of the atrium, the processor preferably moves the elongate member forwards or backwards along the Z-axis, or indicates that it should be moved, to adjust for the possible variations in the anatomy. In this example, the operator can reposition the elongate member, or the processor is preferably coupled to a motor drive unit or other control unit that functions to position the elongate member 18 .
[0063] 7. Method of Collateral Tissue Compensation. As shown in FIG. 11 an exemplary method of collateral tissue compensation includes identifying collateral tissue during a scanning process S 100 and altering the ablation process S 110 .
[0064] Step S 100 , which recites identifying collateral tissue during a scanning process, functions to sense and detect the collateral tissue locations. Preferably, the scanning process occurs during a diagnostic sweep prior to tissue ablation. The diagnostic sweep preferably includes gathering of gap data, tissue thickness, and/or any other suitable tissue information to aid in the ablation process. The diagnostic sweep may alternatively be only composed of the scanning process for collateral tissue. Alternatively, the scanning process may be performed periodically during the ablation process. As another alternative, the scanning process may be performed during a diagnostic sweep and during the ablation process. The collateral tissue identified is preferably any tissue or anatomical structure that is sensitive to ablation, sensitive to overheating, or any other characteristic that may require special treatment during the ablation process, including, but not limited to esophageal tissue and nerves such as the phrenic nerve. The identification of the collateral tissue is preferably a specialized test adapted to identify a single collateral tissue type, or alternatively may identify multiple collateral tissue types that have shared or overlapping properties. The collateral tissue is preferably identified by comparing standardized tissue characteristics with measured tissue thickness, tissue motion, relative position, or any suitable sensible characteristic. As discussed below, Step S 100 may additionally include the additional steps of identifying the phrenic nerve S 102 and/or identifying location of esophagus S 104 .
[0065] Step S 110 , which recites altering the ablation process based on information previously obtained from the collateral tissue identification, functions to modify the treatment of collateral tissue during the ablation process. Preferably, the ablation path is modified to exclude collateral tissue. The ablation path may be altered so the path deviates from the original planned path and merely avoids the collateral tissue. Alternatively, the ablation path may be changed completely as in the case when the collateral tissue makes it impossible to use the originally planed ablation path. As another alternative, the energy beam may be altered to superficially ablate the tissue. This alternative functions to form a transmural lesion, but does so using a specialized technique that is customized to not damage the collateral tissue. The specialized technique may be a faster speed during ablation, lower beam energy, extra tissue sensing, or any other suitable alterations to the ablation process.
[0066] As shown in FIGS. 11 and 12 , Step S 100 may additionally include the additional step of identifying the phrenic nerve S 102 . Step S 102 includes positioning the energy delivery system S 200 , inquiring about the tissue by bumping or electrically stimulating a tissue location S 210 , and monitoring the patient for a reflex response S 220 to the inquiry S 210 . The method of identifying the phrenic nerve functions to utilize the reflex response wherein a person hiccups when his phrenic nerve is physically pushed or electrically stimulated.
[0067] Step S 200 , which recites positioning the energy delivery system, functions to move the energy delivery system to a designated position. Preferably, the designated position is a position that is a part of a diagnostic sweep performed before the ablation sweep. Alternatively, the location of the phrenic nerve may be estimated after the diagnostic sweep (a systematic scan to acquire tissue information). The diagnostic sweep preferably generates an anatomical tissue map from which the phrenic nerve location can be estimated. The estimated location preferably reduces the number of positions through which the energy delivery system must iterate before identifying the phrenic nerve. As another alternative, the position may be the current position of ablation. The phrenic nerve is preferably identified during the ablation process in this alternative.
[0068] Step S 210 , which recites inquiring about a tissue location, functions to apply a mechanical force on the phrenic nerve. The mechanical force preferably incites a reflex response of a hiccup event by the patient. Preferably, the energy delivery device delivers the mechanical force as an ultrasound pulse. The ultrasound pulse is preferably a short duration high intensity signal; a resulting pressure wave then momentarily bumps or deforms the phrenic nerve. The ultrasound may, by a series of pulses, a high or low frequency signal, or any other suitable ultrasound signal, deform the phrenic nerve. Alternatively, the energy delivery system may use a rigid structure that projects outward from the device and that can be used to physically push on tissue locations such as a nerve. The rigid structure may additionally serve other purposes such as a wire to act as the axis of rotation, an elongated member providing slidable z-axis actuation, or any other suitable structure of the energy delivery system.
[0069] Inquiring step S 210 about a tissue location may also be performed by electrically stimulating the tissue. Electrical stimulation of the phrenic nerve will similarly incite the reflex response of a hiccup event by the patient. An exemplary device for electrically or mechanically stimulating the phrenic nerve is discussed below with reference to FIG. 16B .
[0070] Step S 220 , which recites monitoring a patient for a reflex response to an inquiry such as a bump or electrical stimulation, functions to audibly monitor the patient for a hiccup when the phrenic nerve is bumped. The bumping of the phrenic nerve preferably incites an audible hiccup from the patient. A nerve signal, muscle contraction, or any other suitable internal or external reflex response may alternatively be monitored. Preferably, the physician or operator signals to the device through a button or any suitable input device when a hiccup is observed. Alternatively, an audio microphone or any suitable sensor may be used to detect the audible hiccup and electronically signal to the device when a hiccup occurs. The microphone is preferably positioned near the source of the sound such as the mouth or any other suitable position. Another alternative may use a pressure sensor to detect the contraction of the diaphragm during the hiccup. The position of the energy delivery at the time of the hiccup is preferably used to identify the location of the phrenic nerve.
[0071] Referring now to FIG. 16A , catheter 1602 having an energy source and sensor 1604 similar to the embodiment of FIG. 1 is positioned in the heart H in order to identify location of the phrenic nerve P which typically has a left branch LP which passes over the left ventricle, and a right branch RP which passes over the right atrium. Ultrasonic or other energy 1606 is transmitted from the energy source and sensor 1604 to the nerve and then the sensor captures energy 1608 bouncing back from the nerve, thereby allowing the nerve to be located. Alternatively, energy from the energy source provides a mechanical force to the nerve and then the hiccup reflex is monitored separately. FIG. 16B illustrates an alternative embodiment where an instrument 1610 such as a catheter or other device having a flexible wire tip 1612 is used to probe and touch the nerve P causing a hiccup reflex in the patient and allowing the location of the nerve to be determined. In alternative embodiments, flexible wire tip 1612 may also be an electrode that is used to deliver an electrical signal to the phrenic nerve. The electrode may be a monopolar electrode with a return path elsewhere (e.g. a Bove plate), or the electrode may be a bipolar electrode. Wires or other electrical conductors (not shown) may run through the instrument 1610 allowing the electrode to be coupled to a power source and controlled from a proximal end of the instrument 1610 , preferably outside the patient's body.
[0072] Referring back to FIGS. 11 and 13 , Step S 100 may additionally and/or alternatively include the additional steps S 104 of identifying the location of the esophagus. Step S 104 includes inserting an esophageal balloon device into the esophagus S 300 and using an energy delivery system to sense the location of the esophageal balloon device S 310 .
[0073] Step S 300 , which recites inserting an esophageal balloon device into the esophagus, functions to position an esophageal balloon in the esophagus to aid in the sensing of the esophagus location behind heart tissue and may further provide protection of the esophagus during ablation of the heart tissue. The esophageal balloon is preferably composed of a catheter balloon and transponder. The esophageal balloon is preferably a catheter balloon device, which is well known in the art, and additional details are provided below. The transponder functions to be an element detected through the heart and esophagus tissue. Preferably, the esophageal balloon is filled with a fluid such as saline, water, or a gas (e.g. carbon dioxide, air). Liquids such as saline or water are preferably filled with microbubbles to enhance echogenicity. water. The water is preferably sensed by the ultrasound signal of the energy delivery device and functions to be the transponder. The water may further function to cool the esophagus tissue during the ablation process. Alternatively, the transponder may be any active sensor (device sending out a signal) or passive sensor (device able to be sensed without requiring internal power source). The transponder may be a balloon material, a chemical substance, RFID tags, a string of infrared light beacons, an ultrasound transducer, or any other suitable transponder.
[0074] Step S 310 , which recites using an energy delivery system to sense the location of the esophageal balloon device, functions to determine the location of the esophagus behind the heart tissue. Preferably, the energy delivery system can use ultrasound sensing to detect the water within the esophageal balloon. The water preferably generates a unique ultrasound echo that can be distinguished from an echo from tissue. Alternatively, the energy delivery system may include a specialized sensor that corresponds to the type of transponder used in the esophageal balloon. The specialized sensor may be an RFID reader, an IR photodetector, a material sensor, or any other suitable sensor.
[0075] 8.
[0076] While the above is a complete description of the preferred embodiments of the invention, various alternatives, modifications, and equivalents may be used. For example, additional embodiments and additional details on various aspects of an ablation system are disclosed in copending U.S. Provisional Patent Application Nos. 61/110,905; 61/115,403; 61/148,809; 61/109,973; 61/109,875; 61/109,879; 61/109,881; 61/109,882; 61/109,889; 61/109,893; 61/254,997; and U.S. patent application Ser. Nos. 11/747,862; 11/747,867; 12/480,929; 12/480,256; 12/483,174; 12/482,640; 12/505,326; 12/505,335; the entire contents of which have previously been incorporated herein by reference. Therefore, the above description should not be taken as limiting in scope of the invention which is defined by the appended claims.
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A tissue ablation method for treating atrial fibrillation in a patient comprises locating an ostium of a pulmonary vein and positioning an interventional catheter adjacent the ostium. The interventional catheter has an energy source. Collateral tissue adjacent the ostium is located and tissue around the ostium is ablated with energy from the energy source so as to form a contiguous lesion circumscribing the ostium. The lesion blocks aberrant electrical pathways in the tissue so as to reduce or eliminate the atrial fibrillation. The ablating is modified so as to avoid ablating or otherwise damaging the collateral tissue.
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BACKGROUND AND SUMMARY OF THE INVENTION
This is a divisional of co-pending application Ser. No. 139,660 filed on Dec. 30, 1987, now U.S. Pat. No. 4,836,006.
This invention is concerned with a machine that continuously forms pointed terminals from a coil of wire that has not previously been deformed.
This invention is further concerned with a terminal forming machine in which the lengths of the terminals can readily be changed.
This invention is also concerned with a terminal forming machine which can readily be changed to handle wires of various sizes and cross-sectional shapes.
This invention is also concerned with a terminal forming machine that eliminates the need for shears or cutting dies by first deforming the wire with swedges and then twisting the wire at the deformed portion to separate a terminal from the wire.
This invention is also concerned with a terminal forming machine in which the supply of wire for the terminals is fed horizontally into the machine, and the terminals are inserted vertically into plastic parts.
This invention is also concerned with a terminal forming machine that drives the terminals into plastic parts that do not require preformed holes for the terminals.
This invention is also concerned with a terminal forming machine in which the force required to insert the terminals into the plastic parts can be varied.
This invention is also concerned with a terminal forming machine having a terminal inserter which picks up the terminal in a horizontal position and inserts it in a vertical position.
Other concerns of this invention may be found in the following specification, claims and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated more or less diagrammatically in the following drawings wherein:
FIG. 1 is a partial side elevational view of the terminal forming and inserting mechanism of this invention, with a moved position of the terminal inserting mechanism shown in phantom lines.
FIG. 2 is an enlarged partial view of the wire feeding mechanism of the terminal forming and inserting mechanism of this invention showing the wire feeding assembly in a forward feeding position.
FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 2.
FIG. 4 is a front elevational view of the mechanism of FIG. 2.
FIG. 5 is a rear elevational view of the mechanism of FIG. 2.
FIG. 6 is a partial side elevational view of the mechanism of FIG. 2 with the wire feeding assembly shown in a rear position, with some parts broken away and others shown in dashed lines for clarity of illustration.
FIG. 7 is a top plan view of the mechanism of FIG. 6.
FIG. 8 is a side elevational view of the terminal forming mechanism of this invention.
FIG. 9 is a front elevational view of the mechanism of FIG. 8.
FIG. 10 is a cross-sectional view on an enlarged scale, taken along line 10--10 of FIG. 9.
FIG. 11 is an exploded view of the mechanism of FIG. 8.
FIG. 12 is a diagrammatic view of a portion of a length of wire after deforming, but before separation.
FIG. 13 is a diagrammatic view of a portion of a length of wire after the terminal has been deformed from the main length of wire.
FIGS. 14-18 show the sequence of movement of the vertical and horizontal swedges during a wire deformation movement.
FIG. 19 is a front elevational view of the terminal insertion mechanism shown in its inserting position.
FIG. 20 is a side elevational view of the mechanism of FIG. 19.
FIG. 21 is a cross-sectional view, taken along line 21--21 of FIG. 19.
FIG. 22 is a rear elevational view of the mechanism of FIG. 19.
FIG. 23 is a cross-sectional view of the terminal inserting mechanism.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The terminal forming and inserting machine 31 shown in the drawings is used to form short pointed terminals T for insertions in pieces of plastic, which do not require preformed holes for the terminals, from a continuous length of wire W which is supplied from a reel of wire, not shown. The wire W is of non-circular cross section, preferably rectangular or square. Commercially available, standard wire of square cross section, in sizes from 0.015 to 0.060 inches, may be used as the wire W. The machine 31 includes a gooseneck frame 33 (FIG. 1) which is supported on a base 35, which in turn conventionally will rest on a table or other support, which is not shown. A support beam 37 of square cross section is attached to one side of and extends the length of the gooseneck frame 33. A wire feeding mechanism 39 hangs on the support beam 37. This mechanism feeds the wire W to a terminal forming mechanism 41 also supported on the gooseneck frame. From the terminal forming mechanism, terminals T are supplied to a terminal inserting mechanism 43 mounted on the end of the gooseneck frame 33. The terminal inserting mechanism inserts the terminals T in a plastic part 45, held in a fixture 47 supported on a stand 49.
A wire-clamping mechanism 51 engages the wire W to move it forward in steps with the wire clamp moving mechanism 53, which slides on spaced rails 55 (FIG. 2) supported by depending arms 57, which in turn hang down from the support beam 37. The distance of each forward movement of the mechanism 53 is equal to the length of a terminal T. The wire clamp moving mechanism 53 is operated by an air cylinder 59 mounted on a depending support 57 attached to the support beam 37. The air cylinder has a rod 61 (FIG. 7) with a clevis 63 fastened to the end thereof. The clevis 63 receives an integral finger 65 of a plate 67 connected to a mounting plate 69, which is a part of the wire clamp moving mechanism 53. A slide block 71 is also attached to the mounting plate 69, and it rides on the spaced rails 55 (FIG. 3) to carry the wire clamp moving mechanism 53.
The wire clamp mechanism 51 includes a wire clamp base 77, shown in detail in FIGS. 2, 4 and 6. A clamping lever finger 79 is pivotally mounted between two projecting portions of a clamping lever 81 (FIG. 4), also pivotally mounted on the mounting plate 69. An air cylinder 83, also mounted on the mounting plate 69, has a rod 85 which engages the clamping lever to move the lever finger 79 to thereby force the wire W against the wire clamp base 77. As shown in FIGS. 4 and 6, the wire clamp base 77 has a depending lip 87 in which is formed a groove 89 to receive and hold the wire W. The lip 87 does not extend downwardly as far on the right hand side of the groove 89, as viewed in FIG. 4, as it does on the left hand side. This is to permit the wire W to be positioned in the groove by inserting it from the side of the mechanism and to eliminate the need to thread the wire W through the groove 89. The clamping lever 79 has a notch 91 to receive the depending lip 87 of the wire clamp base, as shown in FIG. 2.
A nylon guide screw 95 having an opening therethrough of substantially the same cross section as the wire W (see FIG. 7) guides the wire to the groove 89 in the wire clamp base 77. The nylon guide screw 95 is mounted in a wire guide and stop holder 97, which is attached to one of the depending supports 57 (FIG. 5). A rear stop plate 99 is also mounted on the rear guide and stop holder 97 and engages the plate 67 (FIG. 6) to stop rearward movement of the wire clamp moving mechanism 53. The length of this part can be varied to adjust the rearward movement of the wire clamp moving mechanism 53, thereby varying the length of the terminals T formed by the mechanism. A front stop for the wire clamp mechanism 53 is provided by a bolt assembly 101 (FIG. 1) mounted on the front depending support 57. This assembly has an adjustable jam nut 103, shown in FIG. 7 of the drawings. A front stop 105 attached to the mounting plate 69 engages the bolt assembly 101 to limit forward movement of the wire clamp moving mechanism 53.
The terminal forming mechanism 41 of this invention is shown in relation to the other parts of the terminal forming and inserting machine 31 in FIG. 1 and in detail in FIGS. 8-18 of the drawings. As shown in FIG. 1, it is supported on the gooseneck frame 33 and aligned with the groove 89 of the wire clamp base 77 by means of the support beam 37, which fits in a notch 201 formed in the top of the housing 203 of the terminal forming mechanism in the manner shown in FIG. 9. The housing 203 includes a back plate 205 having a passage 207 with a tapered entrance 209 for the wire W. The passage 207 aligns with the groove 89 in the wire clamp, base-depending lip 87. A rear wire guide 211 is positioned inside the terminal forming housing 203 and has an integral square base 213 and a circular nozzle portion 215. A passage of non-circular cross section conforming to that of the wire W is formed in the square base and circular nozzle by means of an electrical discharge machining process (hereinafter referred to as an EDM process) using a sparking wire which cuts a thin slot through the part to form the passage. The entrance and exit to the passage are tapered for easier passage of the wire W. The rear wire guide 211 is mounted in a gear and swedge block 219, with the square base 213 of the guide seated in a cavity 221 formed in the gear and swedge block. The nozzle 215 of the rear wire guide extends through an opening 223 formed in the gear and swedge block and extends into a circular cavity 225, also formed in this block. A hub 227, shown most clearly in FIGS. 11 and 14 of the drawings, is formed as part of the gear and swedge block 219 and also extends into the circular cavity 225. Intersecting vertical and horizontal passages 229 and 231 are cut through this hub. Cam gears 233 and 235, each having external teeth and internal cam surfaces, are positioned in the circular cavity 225 and rotate about the hub 227.
Vertically-sliding swedges 237 move in the vertical passage 229 and horizontally-sliding swedges 239 move in the horizontal passage 231. Each swedge has a cam follower portion 241 which rides on the cam surface of its gear and a deforming projection or die 243 at the opposite end of the swedge for engagement with the wire W. A pin 245 extends out of each swedge near the cam follower portion and engages a spring 247 captured in a slot 249 formed in the block 219 to bias the swedge toward the cam surface of its gear. Cam gear 233 has cam surface 251, while cam gear 235 has cam surface 253. Plastic spring retaining plates 255 contact the springs and ends of the swedge pins and are held in place by the back plate 205 of the housing 203.
A rack passage 257, shown most clearly in FIGS. 11 and 14, is formed in the terminal forming mechanism housing 203 and intersects the circular cavity 225 so that the teeth of the rack 259, which reciprocates in the rack passage, engage the teeth of both cam gears 233 and 235.
A drive pin 261 extends through both of the cam gears 233 and 235 and projects forward thereof through an arcuate slot 263 formed in plate 265, most clearly shown in FIGS. 9, 11 and 14-18 of the drawings. A square central opening 267 is formed in the center of the plate 265, and a front wire guide 269 is seated in the square opening 267 by means of a square base 271. A passage 273 of the same cross section as the wire W is formed in the front wire guide 269 by means of an EDM process, again using a sparking wire which cuts a thin slot through the part and into the passage.
A wire twister 275 has a hub 277 which fits over the front wire guide 269 and a flange 279 that seats in a recess 281 formed in plate 265. An opening 283 shown in FIG. 9 is formed in the wire twister to receive the drive pin 261 so that the pin can rotate the twister as the pin rotates with the gears 233 and 235.
A passage 285 of the same non-circular cross section as the wire W is formed in the hub portion 277 of the twister 275. This passage is formed in a conventional manner by an EDM process using a thin slot 287 formed in the hub and extending from a drilled hole 289, also formed in the hub. A front plate 291 having a central opening 293 which receives the hub 277 of the twister 275 is fastened to the plate 265 and block 219 to hold the housing 203 together. The rack 259 is reciprocated by a three-position cylinder 299, shown most clearly in FIG. 1 of the drawings.
The terminal inserting mechanism 43 is shown in relation to the terminal forming and inserting mechanism 31 in FIG. 1 of the drawings, and is shown in detail in FIGS. 19-23 of the drawings. It is attached to the forward end of the gooseneck frame 33 at a ball bushing block 321. A pair of spaced slide shafts 323 are slidably mounted in ball bushings 325 (FIGS. 19 and 20) positioned in the ball bushing block 321. An upper cross member 327 is clamped on the slide shafts 323 near the upper ends thereof, while a lower cross member 329 connects the slide shafts at the lower ends thereof. An upper stop plate 331 is mounted on the top of the ball bushing block 321 and a pair of bottom plates 335 are attached to the bottom of the block 321 to retain the ball bushings 325 in the block.
A cylinder support 341 is mounted on the ball bushing block 321 and supports an air cylinder 343, as is shown most clearly in FIGS. 19 and 20. A piston rod 345 extends downwardly from the air cylinder 343 and has a piston rod clevis 347 attached to the end thereof, as shown in FIGS. 19 and 21. A clevis 349 attached to the lower cross member 329 connects with the piston rod clevis 347 to connect the piston rod 345 to the lower cross member 329.
A shock absorber and stop mechanism 353, to limit downward movement of the upper and lower cross members 327 and 329 and slide rods 323, is mounted on the upper cross member 327, and is shown in detail in FIG. 22 of the drawings. This shock absorber mechanism consists of adjustable spring shock absorbers 355 and an adjustable stop lug 357. The adjustable spring shock absorbers 355 engage the heads of bolts 359 mounted in the upper stop plate 331 of the ball bushing block 321, and the adjustable stop lug 357 engages the upper stop plate 331 to limit downwardly movement of the upper and lower cross members 327 and 329 and slide rods 323. A reed switch 361 is mounted on the air cylinder 343 to sense the return of the cylinder piston to its uppermost position. A magnet (not shown) is provided on the piston to actuate the reed switch.
A terminal pickup and holder assembly 371 is pivotally mounted on a shaft 373 supported at its opposite ends in shaft support blocks 375, which are mounted on the lower cross member 329, as shown in FIG. 19. A gear 379, shown in FIG. 20, is fastened to the shaft 373, and this gear is rotated by engagement with the teeth of a rack 381 connected to a piston rod 383 of an air cylinder 385. The cylinder 385 is supported on a cantileverly-mounted block 387, which in turn is supported on the top of an upright 389 attached to one of the shaft support blocks 375. Upper and lower stops 391 and 393 are provided to limit rotation of the terminal pickup and holder assembly 371, as driven by the rack 381 and gear 379.
The terminal pickup and holding member 371 is shown in cross-sectional detail in FIG. 23 of the drawings. It includes a tubular body 399 having a stepped-down nose portion 401 at the free end thereof. The tubular body is formed of two longitudinal half sections 403, see FIG. 19, which are held together at their upper ends by a retaining block 405 and at their lower ends by an O-ring 407. The retaining block 405 holds the tubular body to a pivot support member 409. The pivot support member has a passage 411 which receives the shaft 373 driven by the gear 379. A passage 413 is formed in the nose portion 401 of the tubular member 399 to receive and hold a terminal T pushed out of the terminal forming mechanism 41. The passage is initially formed by an EDM process with the same cross-sectional shape and size as that of a terminal T. In order to more securely hold a terminal T in the passage 413, the passage is slightly reduced in cross-sectional area by cutting the tubular member 399 longitudinally through the passage 413 to form the two longitudinal half sections 403. The provision of the O-ring 407 to hold the lower ends of the half sections together provides the small amount of expansion of the passage 413 necessary to accept the terminal T, while maintaining sufficient force on the terminal to hold it even when the terminal is in a vertical position.
Formed in the tubular body 399 immediately inwardly of the passage 413 are tubular chambers 415 and 417 with each having a larger diameter than the preceding passage or chamber. Located in these chambers is an inertia rod 419. The inertia rod has a cylindrical projection 421 which fits into the chamber 415 and a cap 423 at the opposite end which is seated in the retaining block 405. The inertia rod acts as a stop to limit inwardly movement of a terminal T into the passage 413, and also functions to prevent the terminal T from moving backwards in the passage 413 when it is driven into a plastic part 45. A sleeve 424 encircles a portion of the tubular body 399 and is held in place by an O-ring 425.
The use, operation and function of this invention are as follows.
This invention is concerned with a terminal forming and inserting machine that forms wire terminals T from a continuous reel of wire W that is not required to be deformed, scored or cut prior to installation in the machine. In other words, the machine uses a commercially available wire of square or rectangular cross section that does not require any pre-treatment before it is used to form terminals. The terminals are created from the wire W by deforming the wire at one location but not severing it, and moving the severed or deformed portion to a second location where it is twisted to be separated into a terminal. The machine picks up the terminal T at a third location and inserts it in a plastic part. Because the wire W does not have to be predeformed, scored or cut at the locations of the terminals, it is relatively simple to change the length of the terminals by adjusting the lengths of several of the parts in the machine which determine the length of the terminal. It is also relatively simple to convert the machine to form terminals of larger or smaller cross-sectional areas simply by changing designated parts in the machine. When the cross-sectional area of the terminal is changed, it is also possible with this mechanism to change the amount of force utilized to seat the terminal in the plastic part, and preformed holes are not required in the plastic parts for receiving the terminals. Thus, the holding power of the terminal in the plastic part is greatly increased.
The terminal forming and inserting machine 31 of this invention shown in the drawings is operated by a single operator and is actuated through the use of palm buttons, two in this case, for safety, which are not shown for clarity of illustration. Also, omitted from the drawings and the specification of this invention are the conventional air and electric supply, as well as timers and solenoid valves, which are required to control the operation of the terminal former and inserting machine. These parts which are necessary to the operation of the machine are omitted from this description of the invention since they are conventional and their use, installation and function are well-known to those skilled in this art. The plastic part 45 shown in fixture 47 is depicted diagrammatically only, and it should be understood and appreciated that this part may be of various shapes, and usually a number of terminals T are inserted in each part 45. This part is moved into its various positions relative to the terminal holder 371 by movement of the fixture 47, which again is a conventional device, and the use of such devices is well-known to those skilled in the terminal inserting art.
The operation of the terminal forming and wire-inserting mechanism 31 of this invention will be described through an ordinary cycle of its operation. The wire W extends in a horizontal direction from its reel, which although not shown is located to the rear and below the machine, through the nylon guide 95 which is in the shape of a screw, and between the wire clamp base 77 and the clamping lever finger 79, with the wire W being held in the groove 89 in the wire clamp base. The wire W extends forward from the groove 89 through passage 207 in the back plate 205 of the terminal forming mechanism 41 and then outwardly of the wire twister 275 in the form of a terminal T where the terminal T is picked up by the terminal-holding and inserting mechanism 371.
In a normal sequence of operation there is an intermittent or stepped forward movement of the wire W, in other words to the left as viewed in FIG. 1. The wire is moved by the wire clamp moving mechanism 53. The sequence of operation is as follows.
First, the air cylinder 83 is actuated, extending its piston rod 85 and clamping the wire W between the wire clamp base 77 and clamping lever finger 79, with the wire being located in the groove 89 in the wire clamp base 77. Upon clamping of the wire W the air cylinder 59 is actuated to extend its piston rod 61, the wire clamp moving mechanism 53 and the wire W toward terminal forming mechanism 41 and into passage 207 in back plate 205 of this terminal forming mechanism. The movement of the wire clamp mechanism 53 continues until plate 105 engages stop bolt assembly 101, shown in FIG. 7, which is mounted on the forward depending arm 57. The movement of the air cylinder 83 is reversed to unclamp the wire W from the clamping mechanism. The cylinder 59 is reversed to move its piston rod and wire clamp moving mechanism 53 to the right, as viewed in FIG. 1, until plate 67 on the wire clamp moving mechanism 53 engages stop plate 99 mounted on the rear depending arm 57. This action has moved the wire W one terminal length T to the left, as viewed in FIG. 1.
Referring now to FIG. 10 of the drawings, the movement forward or leftward of the wire W, as viewed in FIGS. 1 and 10, brought about by movement of the piston rod 61 of cylinder 59, moves a portion of the wire W to the circular cavity 225 formed in the gear and swedge block 219. This portion of the wire W has had vertical deformations made in it by dies 243 of the vertical swedges 237, and these vertical deformations are positioned directly in line with the dies 243 of the vertical and horizontal swedges 237 and 239, respectively, as shown in FIG. 10 of the drawings. During the forward movement of the wire W the three-way cylinder 299, shown in FIG. 1 of the drawings, and its rack 259 are in their center positions, shown in FIGS. 15 and 16 of the drawings, in which both the vertical swedges 237 and the horizontal swedges 239 are in their retracted positions due to the shapes of the cam surfaces 251 and 253, respectively, of their gears 233 and 235. When the movement of the wire W is stopped, the piston rod of cylinder 299 and its rack 259 are then fully extended to the position shown in FIGS. 17 and 18 where the horizontal swedges 259 and their dies 215 make horizontal deformations on the wire W. This completes deformation of the wire, shaping the wire into the configuration shown in FIG. 12 of the drawings in which the wire is deformed but not severed. As the rack 259 moves to its lower position the wire twister 275 is rotated by the pin 261 in a clockwise direction, as viewed in FIGS. 15-18 of the drawings, to sever a terminal T from the wire W, as shown in FIG. 13. This severing takes place at the outer end of the front wire guide 269 at a location where the wire had previously been deformed, as shown in FIG. 12. The piston rod of piston 299 is then retracted along with its rack 259 through the center position, shown in FIGS. 15 and 16 of the drawings, in which both the vertical and horizontal swedges 237 and 239 are retracted from engagement, permitting another movement of the wire W by the piston rod cylinder 59. When the piston of piston rod 299 reaches its upper position, shown in FIG. 14 of the drawings, the vertical swedges 239 and their dies 215 are brought in contact with a new portion of the wire brought into position under the dies 243 and the vertical deformations are formed in the wire W. Movement of the rack 259 to its uppermost position, shown in FIG. 14, returns the wire twister 275 in a counterclockwise direction to the position shown in FIG. 14.
After a terminal T is severed from the wire W, it is held in the wire twister 275 with a major portion of the terminal T extending outwardly thereof to the left, as viewed in FIG. 10, until it is forced into the passage 413 in the terminal pickup and holder assembly 371, which is pivotally mounted on the terminal inserting mechanism 43. The passage 413 is of slightly smaller cross-sectional area than that of the terminal T. But because the house 399 is split in two longitudinally-extending sections, held together by the flexible O-ring 407, the terminal T is forced into the passage 413 and held there by the resilience of the O-ring.
Actuation of the air cylinder 385 retracts the rack 381 and through engagement with the gear 379 rotates the terminal holder and inserting mechanism 371 to the vertical position, shown in solid lines in FIGS. 1, 19 and 20 of the drawings. Actuation of the air cylinder 343 extends its piston rod 345 downwardly and moves the upper and lower cross members 327 and 329 and the terminal pickup and holder assembly 371 downwardly until the terminal T is inserted into the plastic part 45 mounted on the fixture 47. Downwardly movement of the terminal pickup and holder assembly 371 is limited by engagement of the adjustable stop lug 357 carried on the upper cross member 327, with the stop plate 331 mounted on the top of the ball bushing block 321.
When the terminal T is inserted in the plastic part 45, the air cylinder 343 is reversed and the terminal pickup and holder assembly is raised, leaving the terminal T embedded in the plastic part. Upper movement of the terminal pickup and holder assembly 371 is stopped when the reed switch 361 indicates the piston of cylinder 343 has returned to its uppermost position. The terminal pickup and holding member 371 is rotated 90 degrees to its terminal pickup position by actuation of the air cylinder 385, which extends its piston rod 383 out of the cylinder 385, as viewed in FIGS. 19 and 20 of the drawings.
Whereas the preferred form of the invention has been shown and described herein, it should be realized that there may be many modifications, substitutions and alterations thereto.
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A method and apparatus for continuously forming pointed terminals from a length of wire. The length of wire is moved to a position where a portion of the wire is positioned between a pair of opposed swedges. The pair of swedges is closed to engage and deform the portion of wire. The wire is then moved to position the deformed portion of wire at a wire severing location and another portion of the wire is positioned between the pair of opposed swedges. The wire is twisted relative to the deformed portion to separate the portion of the wire ahead of the deformed portion to form a terminal. The pair of swedges are closed simultaneously with the twisting to deform the next portion of wire and these steps are repeated.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 08/355,783, filed Dec. 14,1994, abandoned.
FIELD OF THE INVENTION
This invention relates to an improved process for the hydrogenation of anthraquinones in a cyclic process to produce hydrogen peroxide and more specifically to the use of a hydrogenation catalyst comprising palladium on a support.
BACKGROUND OF THE INVENTION
The "anthraquinone process" to produce hydrogen peroxide involves the reaction of 2-alkylanthraquinones, commonly referred to as "anthraquinones" or "quinones", dissolved in a suitable solvent or solvent mixture, with hydrogen in the presence of a catalyst to form the corresponding 2-alkylanthrahydroquinones, commonly referred to as "anthrahydroquinones" or "hydroquinones". These 2-alkylanthraquinones are generally a mixture of both the anthraquinone form and the corresponding 5,6,7,8-tetrahydroanthraquinone form. The alkyl side chain on the anthraquinone can be highly variable, but is usually an ethyl, butyl, or amyl group. The anthraquinone is commonly called the reaction carrier or working material and the anthraquinone-solvent mixture is called the working solution. After reduction, the catalyst is removed and the hydroquinones are oxidized to the original anthraquinones with an oxygen containing gas (usually air) with simultaneous formation of hydrogen peroxide. The hydrogen peroxide is extracted with water and the aqueous solution is purified and concentrated to the desired concentration. The anthraquinone working solution is returned to the hydrogenation reactor to complete the cycle.
U.S. Pat. No. 2,657,980, issued Nov. 5, 1949, discloses the use of a palladium on alumina catalyst in a process to produce hydrogen peroxide. The catalyst support materials are described as activated alumina, at least 50% by weight of which is any natural or synthetic hydrated alumina, dehydrated or partially dehydrated, whereby a microporous alumina is obtained containing alpha alumina monohydrate, gamma alumina or both. The catalyst contains metallic palladium, 0.01 to 10% by weight.
British Patents 718,305 and 718,306, both issuing on Nov. 10, 1954, disclose the use of a palladium hydrogenation catalyst for the production of anthrahydroquinones or anthraquinols and a process to prepare such catalysts, respectively. The catalyst consists of metallic palladium, 0.1-10 wt %, formed by reduction of one or more palladium oxides or basic carbonates preferably deposited on a carrier of alumina, charcoal, magnesia or other suitable support and has a particle size corresponding to a screen aperture between 0.1 inch and 0.001 inch.
British Patent 760,737, issued on Nov. 7, 1956, describes a catalyst for use in the hydrogenation stage of the anthraquinone process prepared by impregnating a silica/alumina carrier with a palladium compound by adsorption from an aqueous solution of a palladium salt, treating the catalyst with an aqueous alkaline solution, followed by reduction. The catalyst, typically 2.3% palladium on 60-150 micron silica/alumina, showed initial productivities of 2.5-4.6 g H 2 O 2 /g catalyst/hr. However, the catalyst was deactivated readily, requiring a more than 10-fold increase in catalyst loading over a 595 hour continuous operation to maintain productivity. This patent also teaches that palladium on silica/alumina catalysts are more active than palladium on alumina catalysts.
Canadian Patent 600,788, issued Jun. 28, 1960, describes a process to prepare catalysts which involves depositing a group VIII metal on an open-surfaced oxide carrier and catalysts prepared by this process. The carrier is an oxide of silicon, aluminum, or a mixture of these, prepared pyrogenically at temperatures between 900 and 1200° C. to form aerogels. These materials and their preparation are described in British Patent 726,250 issued Mar. 16, 1955. Open surface structure, also called porosity factor, f, is defined as having a ratio of the BET surface area to the surface area determined by electron microscopy, of 3-25. These carriers are of a particle size smaller than 2 mesh, and surface area of 10-600 m 2 /g. The surface possesses only a very minor portion of pores.
U.S. Pat. No. 3,030,186, issued Apr. 17, 1962, describes a supported noble metal catalyst (Pd, Pt, Rh, Ru) having a particle size in the range of 4-60 mesh, microporosity (defined as the volume of pores less than 800 Å in diameter) less than 0.03 cc/g, and a BET surface area in general less than 5 m 2 /g. The amount of metal is in the range of 0.1 to 2% by weight. This patent teaches that gamma alumina is an inferior support for use with palladium in the hydrogenation stage of the anthraquinone process due to poor selectivity of this support resulting in formation of undesirable byproducts which are incapable of producing hydrogen peroxide upon oxidation.
U.S. Pat. No. 3,615,207, issued Oct. 26, 1971, describes a hydrogenation catalyst with 0.05-5% by weight of metallic palladium dispersed uniformly over the surface of alumina spheres which are described in U.S. Pat. No. 3,635,841, issued Jan. 18, 1972. The alumina spheres are from about 0.07-0.5 mm in diameter for fluid bed hydrogenations and 0.15-6.5 mm in diameter for fixed bed hydrogenations. The alumina support is predominantly in the delta and theta crystalline phases, being substantially free from alpha- and gamma-alumina, and has pore size of 350-600 microns and BET surface area of 20-200 m 2 /g. These patents teach that a catalyst on an alpha- or gamma-alumina support is not attrition resistant and has a short active life.
While it is known that palladium catalysts on a support are used commercially for the hydrogenation of anthraquinones in the process to produce hydrogen peroxide, there are problems that have been associated with such catalysts. These problems include the following: (1) low catalyst activity which has necessitated high loading of the catalyst in order to achieve high production rates; (2) high loadings of catalyst contribute to increased attrition of catalyst particles and can cause filtration problems and/or downstream contamination resulting in product yield loss; (3) short catalyst life which requires high catalyst turnover or regeneration to maintain a sufficient loading of active catalyst to achieve desired production rates; (4) catalyst loss during regeneration and catalyst loss due to filter leakage requiring significant addition of fresh catalyst to the hydrogenation reaction vessel; (5) high catalyst inventory requirements due to low activity, short catalyst life, high turnover, catalyst losses, and the need to add fresh catalyst.
Conventional supports used to prepare catalysts for the hydrogenation of anthraquinones have high surface areas and small deep pore structures. Due to the size of these pore structures, impregnation of these supports with metals such as palladium deposits much of the metal in regions of the support which are largely inaccessible to the anthraquinone moiety. Consequently, these supports show almost no improvement in hydrogenation activity with increasing metal concentration. The restrictive pore structure of conventional supports also promotes over-hydrogenation of the anthraquinones thereby forming byproducts which do not produce hydrogen peroxide during the oxidation step of the process. These byproducts can build up in the working solution and lower the productive capacity of an operative system. Removal of these components is difficult and requires additional processing as described in U.S. Pat. Nos. 4,668,436, issued May 26, 1987 and 4,544,543, issued Oct. 1, 1985.
The hydrogen peroxide production process of the present invention eliminates these problems and provides superior catalyst performance based on activity, catalyst life, and filtering ability, with very high selectivity relative to catalysts known in the art. Surprisingly it has been found that catalysts prepared on supports with an average pore size of 50-1000 Å, an average particle size of 1-200 microns and a surface area of 20-200 m 2 /g show a dramatic performance improvement relative to catalysts known in the art for the hydrogenation of 2-alkylanthraquinones. Catalysts for this application must also be quite attrition resistant to enable use of normal filtration procedures and to avoid excessive catalyst losses. Some supports, with larger to very much larger pores, although exhibiting excellent activity are not suitable for the slurry hydrogenation stage of the anthraquinone process due to poor attrition resistance.
SUMMARY OF THE INVENTION
The process of this invention for the production of hydrogen peroxide is an improved anthraquinone process, the improvement comprising in the hydrogenation stage of said process the use of a palladium catalyst which consists essentially of 0.2-10% by weight of metallic palladium on a support having pore diameter of from 50-1000 Å, volume average particle size of from 1-200 microns, BET surface area of 20-200 m 2 /g and an attrition resistance greater than 90%.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides an improvement in the hydrogenation stage of the anthraquinone process to produce hydrogen peroxide which involves using a palladium catalyst on a support for the hydrogenation of anthraquinones to hydroquinones. Details of the anthraquinone process of the prior art are described in U.S. Pat. Nos. 2,158,525, issued May 16, 1939, 2,215,883, issued Sep. 24, 1940, and 3,009,782, issued Nov. 21, 1961, incorporated herein by reference.
This invention relates to use of a hydrogenation catalyst which is palladium on a calcined oxide or calcined mixed oxide support having an average pore diameter of 50-1000 Å, a volume average particle size range of 1-200 microns, and a BET surface area of 20-200 m 2 /g
The catalyst support is a calcined oxide or calcined mixed oxide and can be alumina, silica, titania, silica/alumina, and silica/alumina/magnesia and the like. Preferably the support is a high purity gamma alumina, having greater than 90% of the alumina in the gamma crystalline phase. This high purity gamma alumina can be conveniently prepared by starting with a pure boehmite alumina phase produced from the hydrolysis of aluminum alkoxides which can be then dried at 100°-125° C., preferably in a vacuum oven. Calcination can be performed at 450°-800° C., for 2-4 hours.
The catalyst support has an average pore diameter of from about 50 to about 1000 Å, preferably about 60-150 Å. Increasing pore diameter, in a way that the surface area does not decrease, increases catalyst activity and decreases the rate of activity loss, but also makes the catalyst increasingly prone to attrition.
The support has a range of particle size from about 1 to 200 microns, preferably with a volume average particle size of from about 20-80 microns. Smaller particles can improve activity of the catalyst; however, it is desirable that the particles remain large enough for use with conventional filters. The BET surface area of the supports used in this invention is within the range of 20-200 m 2 /g, preferably 120-170 m 2 /g.
The catalysts used in this invention contain from about 0.2 to 10% by weight of metallic palladium, preferably from about 0.5 to 4% by weight, deposited on the supports described above with a dispersion of 20-40%. Dispersion is defined as the percentage of palladium exposed and available for reaction relative to the total palladium content of the catalyst.
In addition to having the aforementioned characteristics of pore diameter, particle size and surface area, the supports of this invention must also possess sufficient physical strength so as to render them resistant to attrition. Attrition generates small particles by wearing down the edges of larger particles or fracturing due to compressive stress and can cause serious problems such as plugging of the filters or catalyst loss due to smaller particles passing through the filters.
Attrition resistance is defined as 100 minus the % change in number average particle size. An attrition test can be used to determine attrition resistance of the supports which involves agitation of an aqueous slurry of the support. Particle size analysis is performed before and after the test to determine changes in particle size distribution. The change either in number average particle size or volume average particle size can be used to measure attrition resistance. Number average particle size is more meaningful because it provides a more sensitive evaluation of attrition resistance as the increase in number of small particles affects the number average particle size more significantly than the increase in volume of small particles will affect the volume average particle size. To illustrate, a support of the prior art with a volume average particle size of 101.9 microns and a number average particle size of 45.0 microns was tested for attrition resistance. After the test, this support had a volume average particle size of 98.0 microns and a number average particle size of 15.2 microns. This means that there was a substantial number of small particles generated indicating poor attrition resistance. Using the same test method, a support of this invention with a volume average particle size of 44.3 microns and a number average particle size of 24.5 microns was tested for attrition resistance. After the test, this support had a volume average particle size of 44.2 microns and a number average particle size of 24.3 microns showing substantially no change in particle size or shape and no generation of small particles. The supports used in this invention can have a change in number average particle size of less than 10% yielding an attrition resistance value of greater than 90%, preferably 5% and 95%, respectively.
Attrition resistance is an important element of the catalyst supports used in the process of the present invention. A test for attrition resistance must be of sufficient duration (time) and generate sufficient collisions between particles (by agitation or other means) to provide reliable data to help select the catalyst support. A test carried out for insufficient duration or collisions can falsely indicate that a catalyst support is attrition resistant. Such catalysts supports will not withstand actual process conditions. The attrition test used to determine attrition resistance in the present invention utilizes agitation of the catalyst support in an aqueous slurry at an agitation rate of 50 feet per second for 1 hour.
The catalysts used in this invention can be prepared using conventional techniques such as the incipient wetness technique or other techniques involving deposition of palladium salts from aqueous media onto supports followed by washing, drying and subsequent reduction of the palladium ion to the metallic state. Alternatively, organometallic palladium compounds and complexes can be used to deposit palladium on the supports in organic media. After removal of the organic solvent, for example, by evaporation, the residue can be treated with heated nitrogen and then reduced with a hydrogen containing gas at elevated temperatures.
The catalysts of this invention are superior relative to catalysts of the prior art in the hydrogenation stage of the anthraquinone process for production of hydrogen peroxide in that more H 2 O 2 per catalyst per time, and more H 2 O 2 per palladium per time can be produced. These catalysts also possess superior catalyst life and have excellent attrition resistance, requiring much less make-up catalyst to be added to the process to maintain production rates, and can be easily managed with conventional filters. These features allow the catalyst to achieve high selectivity by minimizing overhydrogenation thereby reducing quinone consumption and also slowing the rate of catalyst deactivation during extended use.
Yet another advantage of using the supports described in the present invention over microporous supports of the prior art in hydrogenations is that palladium metal is readily accessible for reaction on the supports described herein. Increasing palladium loading on a microporous support gives little to no improvement in the rate of reaction.
Often catalysts possessing very high activity exhibit poor selectivity when compared to their less active counterparts. However, the catalysts of the present invention show excellent selectivity in the hydrogenation of 2-alkylanthraquinones in the process to produce hydrogen peroxide.
Supports made from alumina, silica, titania, or mixtures such as silica/alumina, or silica/alumina/magnesia which have structures with the combination of characteristics described herein work equally well. For a general description of alumina including information on calcination conditions, pore structure, crystalline forms see Kirk-Othmer "Encyclopedia of Chemical Technology", third edition, volume 2, John Wiley & Sons, pp. 218-244 and "Catalyst Supports and Supported Catalysts", by Alvin B. Stiles, Butterworth Publishers, 1987, pp. 11-55.
The process of the present invention using the catalysts of this invention in the hydrogenation stage of the anthraquinone process to produce hydrogen peroxide can operate within conventional ranges of temperature and pressure. In this invention, the working solution is an anthraquinone in a solvent or solvent mixture. The hydrogenation of the anthraquinone working solution can be performed at pressures between atmospheric to 60 psia, preferably between atmospheric and 40 psia and at temperatures between ambient or about 20° C. to about 150° C., preferably, the temperature is between 35° C. and 65° C. The catalysts are suitable for use in free suspension in a hydrogenator and are of such a particle size that separation from the anthraquinone working solution can be achieved simply by filtration. The hydrogenation can be performed as a batch or continuous operation.
The hydrogenated anthraquinone working solution can then be oxidized with air or an oxygen containing gas and subsequently extracted or stripped to remove the formed hydrogen peroxide as described in the above referenced U.S. Pat. Nos. 2,158,525, 2,215,883, and 3,009,782. The extracted working solution is then recycled to the hydrogenation step.
In the process of this invention, it is the combination of features of the catalysts working synergistically that increase activity and selectivity in the hydrogenation stage of the anthraquinone process to produce hydrogen peroxide. Consequently, quinone consumption is reduced and the rate of catalyst deactivation is slowed, which is particularly in evidence during extended use. The catalysts described herein have been used in continuous operation for months without loss of productivity.
EXAMPLE 1
In a 1.75-liter continuously stirred tank-type reactor with internal filters to retain the catalyst inside the reactor, operating at a volume of 1.25 liters, a temperature of 43°-45° C. and pressure of 15 psig, a working solution was circulated at a flow rate of 50 ml/min. The working solution initially contained 18 wt % ethylanthraquinone, of which 45 wt % was tetrahydroethylanthraquinone, 58 wt % of an aromatic solvent (alkylated benzenes - heavy naphtha fraction, Aromatic 150), and 24 wt % tetra-n-butylurea. The hydrogen feed rate was controlled to give a maximum reduction level (anthrahydroquinone or HQ titer) of 0.408 g mol/l. 2.254 g of a 2.6 wt % palladium on gamma alumina catalyst was added to the reactor.
The catalyst had average pore size of 114 Å, average particle size of 44 microns, surface area of 158 m 2 /g. Pore size was determined by nitrogen sorption using the BJH method described in Barret, et al., J. Am. Chem. Soc., 1951, vol. 73, p. 373. Particle size was determined on unsonicated samples using a Microtrac Particle Analyzer, available from Leeds & Northrup. Surface area was determined by the BET method described by Brunauer, et al., in J. Am. Chem. Soc., 1938, vol. 60, p. 309.
An attrition test was performed by preparing an aqueous suspension of the support material at a solids concentration of 30 g/l. This slurry was placed in a 2.5 gallon baffled vessel using a 3.75 inch pitched turbine blade agitator. The slurry was agitated at a tip speed of 50 ft/sec for 60 minutes. For the attrition test, particle size analysis was performed using a Coulter Counter Multisizer II. The number average particle size was 9.45 microns initially and 9.46 microns after the test, showing an attrition resistance of 100%.
The activity of the catalyst was monitored over time by following the loss of reduction level of anthraquinones to hydroanthraquinones by determining the concentration of anthrahydroquinones in the working solution by oxidation of this solution to hydrogen peroxide and titration of the hydrogen peroxide with a standard permanganate method as described by Vogel in "Quantitative Inorganic Analysis", third edition, Longmans, Green and Co., London, 1961, p. 295. After 44.8 hours, the reduction level had dropped to 0.304 g mol/l. Catalyst additions were subsequently made at time intervals to reach and maintain a stable reduction level of 0.360 g mol/l. Time, catalyst amounts, HQ titer and productivity are shown in Table 1.
TABLE 1______________________________________ Catalyst HQ ProductivityTime (cumulative titer (g H.sub.2 O.sub.2 /g(hr) total, g) (g mol/l) catalyst/hr)______________________________________0 2.254 0.380 17.244.8 0.304 13.845.6 2.857 0.318 11.468.9 0.318 11.469.5 3.873 0.352 9.3163.4 0.346 9.1164.0 4.414 0.394 9.1211.5 0.372 8.6348.7 0.360 8.3635.5 4.414 0.359 8.3______________________________________
In comparison, the process as described above was repeated using a 0.6 weight % palladium on alumina catalyst. This catalyst had an average pore size (diameter) of 28 Å, an average particle size of about 80 microns, a surface area of 213 m 2 /g and attrition resistance of 73%. Such a catalyst system is outside the scope of this invention.
The initial catalyst addition was 10.055 g, which resulted in an initial reduction level of 0.256 g mol/l. The activity of the catalyst was monitored as described above. After 23.63 hours, the reduction level had fallen to 0.21 g mol/l. Catalyst additions were made with the goal of reaching and maintaining a stable reduction level of 0.360 g mol/l. Time, catalyst amounts, HQ titer and productivity are shown in Table 2.
TABLE 2______________________________________ Catalyst HQ ProductivityTime (cumulative titer (g H.sub.2 O.sub.2 /g(hr) total, g) (g mol/l) catalyst/hr)______________________________________0 10.055 0.256 2.623.6 0.201 2.024.1 16.009 0.285 1.847.2 0.265 1.748.1 22.014 0.3165 1.571.0 0.301 1.471.8 26.032 0.3505 1.494.9 0.337 1.395.5 28.036 0.360 1.3119.0 0.3385 1.2119.5 30.537 0.359 1.2129.0 0.3345 1.1129.5 33.05 0.360 1.1199.7 0.3265 1.0200.3 36.10 0.372 1.1289.3 0.350 1.0______________________________________
The comparison of the data in Tables 1 and 2 shows that the catalyst system of this invention affords surprisingly large improvements over the catalysts of the prior art.
EXAMPLE 2
A glass jacketed hydrogenation vessel with internal baffles equipped with a highly efficient gas dispersing turbine (similar in design to a stirred tank reactor described in Ind. Eng. Chem. Res., 27,278 (1988) but with a reduced volume suitable for hydrogenation of a 100 ml volume of working solution) was purged with nitrogen. To the vessel was added 100 ml of working solution of a mixture of 2-ethyl, 2-butyl, 2-amyl anthraquinone, 24% by weight of the working solution, having about 55% of the quinones present in the form of tetraalkylanthraquinones, and a mixed solvent system containing an aromatic solvent of alkylated benzene, "Aromatic 150", 54% by weight of the working solution, and a polar solvent, diisobutylcarbinol, 22% by weight of the working solution, followed by 120 mg of 2.6 wt % palladium on gamma alumina catalyst, as described in Example 1.
The temperature of the vessel was brought to 35° C. and maintained at this temperature by recirculated water while stirring the mixture at a rate of 300 rpm over a period of 5-7 minutes then, momentarily, at 2500 rpm then stopped.
Hydrogen was admitted to the vessel at a rate of 100 cc per minute and allowed to stand under hydrogen purge for 5 minutes. The contents were agitated at 2500 rpm for 8 minutes. Inlet flow of hydrogen during this time was adjusted as needed to maintain a modest vent gas rate so as to prevent any backflow of air into the system. After this time, the gas flow was changed from hydrogen to nitrogen and was allowed to flow for 5 minutes.
The hydroquinone so produced was converted to H 2 O 2 by oxidation. To analyze for hydrogenation catalyst efficiency, the reaction mixture was filtered through a 0.2 micron pore size medium. A 5-ml portion of the 100 ml of the reduced working solution filtrate was transferred to a 300-ml Morton flask with a drain containing 200 ml of deionized water and 5 ml of o-xylene. This mixture was stirred and sparged with oxygen for 10 minutes. The oxygen was turned off and stirring was stopped. The mixture was allowed to settle for 5 minutes and the aqueous portion (which now contained hydrogen peroxide) was transferred into a beaker. A second 200-ml quantity of deionized water was added to the remaining o-xylene solution in the flask. The mixture in the flask was again stirred and sparged with oxygen for 5 minutes. After 5 minutes to allow for settling, the water was again drawn off into the same beaker.
This 400-ml aqueous peroxide solution was stirred; to a 100-ml aliquot of this solution was added 25 ml of 3 N H 2 SO 4 and 2 drops of ferroin indicator and was titrated with a 0.10 N Ce (IV) solution to an endpoint indicated by a color change from red-orange to clear-blue. The volume of Ce (IV) solution utilized was 3.1 ml (0.0031 eq) corresponding to 0.000155 mole or 0.00527 g of H 2 O 2 in the 100-ml aliquot or 0.0211 g H 2 O 2 (0.00062 mole) in the 5 ml of oxidized working solution. This, in, turn, corresponds to 0.124 mole of H 2 O 2 per liter of working solution produced, requiring. 0.124 mole H 2 . Multiplying by 22,400 ml H 2 per mole H 2 and dividing by reaction time (8 minutes) and catalyst amount (1.2 g per liter of working solution), the activity of the palladium hydrogenation catalyst was calculated to be 289 ml H 2 per liter of working solution per minute per gram catalyst.
EXAMPLE 3
A series of palladium on gamma alumina catalysts with increasing palladium loadings was examined following the procedure of Example 2. The alumina support used in these examples had average pore diameter of 113 Å, average particle size of 57 microns, surface area of 162 m 2 /g and attrition resistance of 96%. For each catalyst, the process of Example 2 was repeated using 120 mg of catalyst. The activities of the catalysts were determined in the same manner as described above. Palladium loading and catalyst activity are shown in Table 3.
TABLE 3______________________________________Palladium Catalyst Activity (ml H.sub.2 /min/Loading (wt %) 1 working solution/g catalyst)______________________________________0.5 1151.0 1642.0 2522.5 286______________________________________
In comparison, a series of palladium on alumina catalysts outside of the scope of this invention, wherein the alumina support had a microporous structure was examined. The alumina support used in these tests had an average pore diameter of 35 Å, average particle size of about 80 microns, surface area of 330 m 2 /g and an attrition resistance of 34%. Catalyst samples containing 0.08 wt %, 0.20 wt %, 0.40 wt %, 0.80 wt % and 2.4 wt % palladium were prepared. For each such catalyst the process of Example 2 was repeated using 500 mg of catalyst. The activities of the catalysts were determined in the same manner as described above. The activities of these catalysts were identical to each other, 22 ml H 2 /min/l working solution/g catalyst. In addition to the very low catalyst activity, these catalysts do not meet the attrition resistance requirement for long term use and, unlike the catalysts of this invention, these catalysts show no benefits in activity by increased palladium loading.
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An improved process for producing hydrogen peroxide by the anthraquinone process, utilizing a palladium on calcined support catalyst having high attrition resistance, is provided.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an optical information recording medium for recording and/or reading information optically, in particular, relates to an optical disk technique.
[0003] 2. Description of Related Art
[0004] As one way to achieve a high capacity optical disk, a multilayered medium technique having a laminated information recording layer has been proposed. As a read-only disk, a dual-layered DVD-ROM is achieved. As for a rewritable dual-layered medium, Japanese Journal of Applied Physics Vol. 38, pp. 1679 to 1686 (1999) introduces such a technique therein, for example. In these techniques, a recording layer is cumulated with an interval of several 10 μm, and recording/reading information by focusing optical spots onto each layer. Information on a side further than an incident light is recorded/read as the light passes through the layer on the side of the incident light. When reading the information, the light passes the layers on the side of the incident light twice.
[0005] These techniques can increase a recording capacity of a medium of the same size about twice.
[0006] JP-A-21720-1993 discloses a triple-layered recordable medium using a high transmittance organic recording film. In this method, transmittances of three layers are 70%, 80% and 90%, respectively, and a recording mark thereof is 100%. By detecting an amount of transmitting light, data recorded on three layers are read at the same time. The method is capable to increasing a recording density and data transfer rate by about three times.
[0007] As for an optical disk using a nonlinear optical layer, a method of photon super-resolution is proposed. Several methods using this technique have been proposed, and Japanese Journal of Applied Physics Vol. 32, p. 5210 discloses one of them, for example. The method is characterized in that by providing a mask to a part of optical spot so as to transmit light only through an unmasked portion, an effective spot diameter is reduced, thus increasing density and capacity of the optical disk. Specifically, in the photon super-resolution, when the light focuses on a film, the light transmittance of the light of higher intensity is increased whereas reflectance of non-focused portion is high. In known techniques in the photon super-resolution, a medium has reflective films, and transmittance of the medium itself is always substantially 0%.
[0008] The abovementioned techniques, however, have some problems. In recordable and rewritable optical disks, in particular, it is difficult to form a dual-layered medium that secures a process margin in consideration of mass productivity and products or margins for recording/reading condition. This is because it is difficult to achieve an optimum optical design allowing for high signal modulation in both layers. To increase the signal quality obtained from the light-incident side, the transmittance of the layer should be lowered and it is better to increase reflectance and create larger differences in reflectance between a marked portion and a spaced portion. On the other hand, however, for the layer of further side, the higher the transmittance of the layer on the light incident side is, the higher signals can be received. As such, as for setting transmittance of the light incident side layer, the signal needs to be shared by two layers because the optimum transmittance for both layer contradicts. More details thereof will be described hereinbelow.
[0009] Hereinbelow, a dual-layered phase change medium will be described. Hereinbelow, L 0 denotes a layer on a side of incident light, L 1 denotes a layer on further side, Rc denotes disk reflectance of crystal, and Ra denotes amorphous thereof. Rc and Ra of L 0 and L 1 are shown respectively as Rc 0 , Ra 0 , Rc 1 , and Ra 1 . An amount of reflected light/incident light, i.e., drive reflectance, is shown Rcd and Rad, and transmittance of L 0 is shown as TO.
[0010] Suppose T 0 =60% and (Rcd, Rad)=(15%, 2%). The reflectance shown is values close to reflectance of a phase change disk that is currently produced. It is desirable to obtain the same amount of signal from L 0 and L 1 . Calculation of reflectance while taking the above into consideration, a setting value for reflectance of the L 1 is (Rc 1 ,Ral)=(41.7%, 5.6%). However, it is difficult to design disk for a phase change medium capable of overwriting that has reflectance of 40% or higher. If T 0 is set higher than 60%, reflectance and light absorption of the L 0 is lowered significantly, and it becomes impossible to obtain desirable property at the L 0 . Moreover, it is necessary that the transmittance is substantially the same as crystalline state and amorphous state due to the following reason: the L 0 has a marked portion and an unmarked portion, and if the light spot passes on a border of two area of the L 0 as the light reads the L 1 , the direct current element and amplitude of the signal in reading L 1 fluctuate, thereby causing an increase of jitter or error rate. Therefore, accidental error of transmittance for those two states should be suppressed less than 5 to 10%. However, maintaining translucent transmittance with the range is difficult when considering the process margin.
[0011] Moreover, even a dual-layered medium generates problems such as above, it is almost impossible to achieve a recordable/rewritable optical disk having three or more layers.
[0012] The triple-layered recordable disk technique described above detects transmittance. In this method, however, optical systems need to be placed on the top and the bottom of the disk. Such a structure makes it difficult to adjust the optical systems, thereby lowering production margin of the drive. Moreover, the method is not applicable to a rewritable disk.
[0013] In the super-resolution technique, an effective spot diameter can be smaller, thus allowing for higher density. However, the technique has drawbacks as follows: A. When considering a process margin for mass productivity, it is difficult to make a size of the light transmitting portion constant over an entire surface of the disk; B. In the optical disk, a signal noise ratio S/N becomes an issue, and an area of an effective spot as a part of the spot diameter determines the signal while a spot diameter irradiating the disk determines the noise, whereby the signal is increased for a short mark but overall S/N including the one for a long mark is lowered.
SUMMARY OF THE INVENTION
[0014] In view of the above, the transmittance of L 0 should be high at least while reading the L 1 in consideration of the L 1 . When reading the L 1 , a signal for reading the L 1 is determined by a square of the transmittance of L 0 , that is T 0 2 . A value of the obtained signal should be no lower than a half of the signal obtained from a single layer of L 1 , thus desirable as expressed in:
T 0 2 ≧50%
∴T 0 ≧71% EXPRESSION 1
[0015] In the case of a triple-layered medium, the signals are determined by a square of transmittance of L 0 when reading the L 1 , i.e., T 0 2 1 , and a product of squared transmittance of L 0 and L 1 , i.e., T 0 2 T 1 2 , when reading the L 2 . In this case, each signal for reading L 0 and L 1 is desirable as expressed by:
T 0 2 ≥ 2 3 = 67 %
∴ T 0 ≥ 2 3 ≈ 82 % EXPRESSION 2
T 0 2 T 1 2 ≥ 1 3 = 33 %
∴ T 1 ≥ 1 2 = 71 % EXPRESSION 3
[0016] When the expressions are generalized, transmittance for reading a J th layer of an n-layered recording medium can be expressed as:
∏ i = 1 j - 1 T i 2 ≥ n - j + 1 n , EXPRESSION 4
[0017] where i-layer and i-layer used herein mean a laminated film interposed between a substrate and spacer layer, or a laminated film interposed between a spacer layer and another spacer layer, the i-layer or the j-layer composed of a lower protective layer, a recording layer, an upper protective layer, a nonlinear optical layer or a reflective layer.
[0018] However, as described above, it still has high transmittance, thereby making it difficult to design the L 0 . Such a problem can be solved by producing a medium where the transmittance is lowered and reflectance enhanced as the light focuses thereon. Such a mechanism will be described later.
[0019] In the above-described Expression 4, transmittance of the first layer to the j-1 th layer is dealt with all together, but it is desirable to design in such a manner that a signal is equally divided among respective layers. In the case of a triple-layered medium, for example, T 0 and T 1 fulfilling Expressions 2 and 3 is:
T 0 ≥ 2 3
T 1 ≥ 1 2 . EXPRESSION 5
[0020] By generalizing the expression, transmittance Ti of the i th layer only needs to fulfill
T i ≥ n - i n - i + 1 . EXPRESSION 6
[0021] Moreover, it is possible to design a medium that secure the process margin if the transmittance is 50% or less when the light is focusing. In this case, signals on layers further than a light-focusing layer seeing from the light incident layers is not read, and thus, it is not necessary to consider differences in transmittance of crystal and amorphous as described above. The transmittance is low enough to make designing a medium while securing process margins easier. In the present specification, a phrase “when the light is focusing” herein is defined as a case when a light spot diameter on a film surface becomes 105% or less of a size of a minimum beam constriction of the optical system concerned. A term “spot diameter” used herein means a diameter of intensity of 1/e 2 of the central intensity when the spot of the light approximated to the gaussian distribution. When the spot diameter spreads by 5%, the central intensity is about 90%, thereby it is considered within a margin of mechanism shown below.
[0022] A medium that changes transmittance and reflectance, as described above, can be achieved by using a substance whose optical property changes depending on an energy density of a light applied to the L 0 , i.e., by using a nonlinear optical layer. When the nonlinear optical layer is provided between the L 0 recording film and L 1 recording film, the nonlinear optical layer should be composed of a material that is transparent or translucent when the light is not focused on the L 0 recording film, and has a higher reflectance when the optical spot focuses on the L 0 recording medium compared to a case where the light is not focused. Such a change occurs due to absorption of the light. That can be achieved by either using a photon mode or the heat generated by the light absorption. The change should occur by depending on the light power density applied to the substance. In order to read the L 1 immediately after reading the L 0 , the change has to return to an original state within a certain period of time, and the transmittance of the L 0 has to be high again. It is desirable that it returns to normal naturally during one disk revolution, for example. If the change occurs by heat, the temperature should return to the original during one disk revolution so as to reverse the change to the original state.
[0023] The mechanism is not only applicable to a dual-layered medium but to a multilayered medium having 2 or more layers.
[0024] [0024]FIG. 1 illustrates the mechanism. When the light of high power density does not irradiate a nonlinear optical layer 104 , i.e., when there is not incident light, and when recording and reading the L 1 , reflectance of the nonlinear optical layer 104 is low while transmittance is high. On the other hand, when recording/reading the L 0 , a portion 110 irradiated with light becomes metallic, thereby increasing the reflectance.
[0025] The above-described object is achieved by providing a nonlinear optical layer between a substrate and a second recording film (L 0 layer), the nonlinear optical layer has a property in which the transmittance thereof is higher than the reflectance when the light is focusing, and the reflectance is higher than the transmittance when the light is not focusing. The recording layers are not limited to two layers, and the structure is applicable to a multilayered recording medium having more than two recording layers.
[0026] The following materials may be used as a nonlinear optical layer: a) thermochromic material, b) transition metal oxide showing semiconductor-metal transition, c) garnet, and d) magnetic semiconductor.
[0027] The thermochromic material changes wavelength dependency of reflectance and transmittance reversibly by temperature. One example thereof is a material of triphernylmethane dye. A super-resolution optical disk using the aforementioned material is disclosed in Japanese Journal of Applied Physics Vol. 39, pp 752 to 755 (2000).
[0028] A semiconductor-metal transition is known to occur with temperature, pressure, and compound composition ratio as its variables. In this case, a material causing the transition by temperature thereof is selected. Such a material may include oxide of Ti, V, Cr, Mn, Fe, Co, Ni and Cu. The heat dependency of electronic properties of these materials is described in, for example, Solid State Physics, Vol. 21, pp 1 to 113 (1968). If the material is solely used, optical property such as refractive index thereof before and after the transition does not change much in the wavelength range of visible light used in the current optical disks. A fact regarding V 02 is reported in Physical Review, Vol. 172, pp. 788 to 798 (1968). In order to solve the problem, free electrons generated in the transition metal oxide due to the transition is injected into another material A so as to change an optical response of the material A. In this case, the material that changes its optical response by the injection of electric charge may be metal or semiconductor. In particular, when the semiconductor is used, electric charge is injected into a conduction band so as to increase the number of carriers comparing to that before the transition, thereby increasing the effect thereof. In order to inject the electric charges efficiently, Fermi energy level of the material A should be smaller than Fermi energy level of the transition metal oxide indicating the transfer. Moreover, the injection of the electric charge is conducted through an interface. Thus, the larger an area of the interface is, the easier the electric charge is injected. Therefore, more electric charges can be injected if the material A and the transition metal oxide are formed in a multilayered film structure.
[0029] Next, a case of using a magnetic material will be described. Among the magnetic materials, there is a kind that shows magnetic transition due to heat while changing the optical property simultaneously. Garnett, in particular, shows a strong tendency for this change. FIG. 2 shows a temperature dependency of the transmittance of a bulk crystal of garnet having Ga doped thereinto. A wavelength of the light used herein is 400 nm. In FIG. 2, the transmittance decreases drastically at around 120° C. A Curie temperature of the material is about 120° C., and thus, a change in transmittance occurs due to magnetic phase transition.
[0030] When a magnetic semiconductor is used, a band structure change due to magnetic property contributes a great deal to a change of an optical property. A temperature dependency of the optical property of the magnetic semiconductor is described, for example, in Semiconductors and Semimetals, Vol. 25, pp. 35 to 72 (1988). The magnetic semiconductor of this kind includes a material shown as RMnM, where R is a simple substance or mixture of Cd, Zn, Hg, and Pb, and M is O, S, Se, and Te. RPnM may be used as a simple substance, or may be mixed with other materials in some cases.
[0031] When the above-described nonlinear optical material is applied to a multilayered disk, it is designed in such a manner that the transmittance is high when no focused light is applied whereas it becomes low when the focused light is applied. In particular, when applying to a phase change disk, a phase change recording film absorbs the light, and thus, it is desirable to design the material to have an absorption factor of substantially 0 when the transmittance thereof is high. In this case, however, it is impossible for the nonlinear optical material to indicate transmittance change due to the light absorption. The problem can be solved by transferring heat from a film near the nonlinear optical layer that absorbs light if the nonlinear optical material indicates transmittance change by heat. The film for absorbing the light may be a recording film like a phase change film described above, or may be formed by laminating a film of metal or semiconductor within the disk. In order to transfer heat efficiently, a distance between the light absorbing film and the nonlinear optical material has to be shorter, and a thickness of the metal film or semiconductor therebetween needs to be from 0 nm to 50 nm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] [0032]FIG. 1 is a diagram illustrating a structure of a dual-layered disk according to the present invention;
[0033] [0033]FIG. 2 is a graph showing a heat dependency of transmittance of a bulk monocrystal of garnet with GA doped therein;
[0034] [0034]FIGS. 3A to 3 G illustrate production steps of a dual-layered medium;
[0035] [0035]FIG. 4 is a block diagram of an optical disk drive for recording and reading a multilayered disk according to the present invention; and
[0036] [0036]FIG. 5 is a diagram illustrating a structure of triple-layered disk according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] Embodiment 1
[0038] As a nonlinear optical layer 104 of FIG. 1, a multilayered structure of VO 2 and GaN is used. A laminated structure of L 0 is polycarbonate substrate of 120 mm in diameter (100 μm)/a protective layer/a recording film InSe (5 nm/a protective layer/GaN (2 nm)/V 02 (2 nm)/GaN (2 nm)/VO 2 (2 nm). A laminated structure of L 1 is a protective layer/a recording film InSe (22 nm)/a protective layer/a reflective film (80 nm)/120 mm diameter polycarbonate substrate (1.1 mm). All films are formed by sputtering. A resin layer (spacer layer) of about 30 μm is arranged between L 0 and L 1 . The polycarbonate substrate of 1.1 mm in diameter has grooves with a depth of about 40 nm and a width of 0.3 μm, with a pitch of 0.6 μm. Specifically, it has a land/groove structure.
[0039] [0039]FIGS. 3A to 3 G shows a production process of the disk in sequence. As shown in FIG. 3A, a polycarbonate substrate 301 with a thickness of 1.1 mm is provided with a land/groove structure. On top of the polycarbonate substrate 301 , a reflective film 302 , a protective film and recording film 303 are sputtered as shown in FIG. 3B. Next, a resin 304 for a spacer layer is attached, and a stamper is pressed against the resin to cure the resin as shown in FIG. 3C, so as to form a land/groove pattern for the L 0 as shown in FIG. 3D. Thereafter, as shown in FIG. 3E, a nonlinear optical layer 305 (GaN (2 nm)/VO 2 (2 nm)/GaN (2 nm)/VO 2 (2 nm)), a protective film, and recording film 303 are sputtered. Herein, GaN is sputtered while mixing with 1% of N 2 into Ar atmosphere. VO 2 is sputtered by mixing 1% of O 2 into Ar atmosphere by using a V target. Lastly, as shown in FIG. 3F, resin for gluing the sheet 306 is attached, a polycarbonate sheet 307 with a thickness of 0.1 mm is glued therewith as shown in FIG. 3G. The disk is completed by curing the resin 305 . Refractive indices of the resins 304 and 306 and 0.1 mm sheet 307 are generally the same. The difference in the refractive indices is less than 0.1.
[0040] Marks were recorded/read on this disk through an objective lens with a numerical aperture of 0.85 by the light with wavelength of 400 nm. The recording/reading drive used herein is a conventional drive as shown in FIG. 4. A semiconductor laser 401 as a light source is driven by a laser driving circuit, and emits linearly polarized laser beam. The light becomes parallel beam by a lens 402 , passes though a beam splitter 403 so as to become circularly polarized light at a ¼λ plate 404 . The circularly polarized light is focused on a disk 407 by a lens 405 attached to an actuator 406 . The reflective light from the disk 407 returns to the lens 405 , and becomes linearly polarized light having reverse direction from the incident light at the ¼λ plate, so as to distort the light path by the beam splitter 403 . The light passes through a lens 408 , divided by a knife-edge prism 409 . One of the divided lights enters a two-division optical detector 410 for auto-focusing servo, and the other enters a two-division optical detector 411 for reading/tracking system. A ratio of light amount splitting of the knife-edge prism is the detector 410 : the detector 411 =1:9.
[0041] A signal obtained by the optical detector 410 is taken for its subtracted signal. The subtracted signal is divided by a reading signal, and input to an electronic circuit for auto-focusing servo for dual-layered disks. The actuator 406 moves the lens 405 for auto-focusing. The signal input to the auto-focus servo circuit changes as a focusing point of laser beam in the disk 407 moves, and when focused, it becomes 0. When the disk is dual layered, and the transmittance of the L 1 is substantially 0, the light focuses on a surface of the sheet 307 , the L 0 , and L 1 because difference in the refractive indices between the resins 304 , 306 and the sheet 307 are minute. When performing auto-focusing, the lens 405 moves closer to the disk to count the number of 0 cross points of the signal, it is possible to identify where the laser beam focuses on the disk 407 currently. Moreover, when the laser beam focuses on the L 0 , for example, and moves to the L 1 , the lens 405 moves to further side of the disk, and stops the move when the next 0 cross point is detected.
[0042] A sum signal of the signal obtained by the optical detector 411 is input to an RF signal system, and a subtracted signal thereof in input to a tracking servo circuit as a push/pull signal. The actuator 406 moves the lens 405 so as to conduct tracking servo.
[0043] The above-described drive uses a knife-edge method for auto-focus, and a push-pull method for a tracking. Alternatively, an astigmatic method may be used for focus, and a 3-beam differential push-pull method may be used for tracking, for example.
[0044] Before evaluating the dual-layered medium described above, a single layer disks having structure of L 0 and L 1 are formed, respectively for evaluation. The reflectance and transmittance of the L 0 are measured by a spectrophotometer to find that the reflectance and transmittance of crystal and amorphous thereof, i.e., Rc, Ra, Tc, Ta, are (RcO, RaO, TcO, TaO)=(5%, 5.5%, 71%, 62%), correspondingly, and for the L 1 , (Rc 1 , Ra 1 )=(20.3% and 6.2%).
[0045] For evaluation of the dual-layered medium, the L 0 is focused first. The reflectance calculated from an amount of reflecting light obtained at the drive, i.e., the drive reflectance is (Rc, Ra)=(10.7%, 3%). The result is different from the value obtained by a spectrophotometer as described above because refractive indices of V 02 and GaN have changed due to semiconductor-metal transition. A laser beam pulse irradiates the L 0 to record mark of 0.194 μm long by linear velocity of 6 m/s. CNR and 50 dB are obtained. When random pattern is recorded by using 8-16 modulation code, jitter is 8.5% for the first recording, and 9.3% after overwriting 1000 times.
[0046] Next, the laser beam is focused on the L 1 . The reflectance of the L 1 is (R 1 c, R 1 a)=(10.1%, 3%). The transmittance of the L 0 is 71% when in crystal, is about a half of the reflectance of the L 1 single layer observed by spectrophotometer, since 0.71 2 ≈50%, which agrees with the calculation. When marks are recorded in the L 1 under the same recording condition for the L 0 , jitter is 8.7% for the first recording, and 9.6% after overwriting 1000 times.
[0047] Embodiment 2
[0048] As a layer 104 in FIG. 1, a mixed material of triphernylmethane dye material and color development material is used. A laminated structure of L 0 is polycarbonate substrate of 120 mm in diameter (0.6 mm)/a protective layer/a recording film InSe (10 nm)/a protective layer (10 nm)/dye (60 nm). A laminated structure of L 1 is a protective layer/a recording film InSe (16 nm)/a protective layer/a reflective film (80 nm)/120 mm diameter polycarbonate substrate (0.6 mm). The substrate of the medium has grooves with a depth of about 70 nm and a width of 0.615 μm, with a pitch of 1.23 μm.
[0049] The production method of the medium is the same as the method described in Embodiment 1 as shown in FIGS. 3A to 3 G. A dye as a nonlinear optical material is formed by vapor deposition.
[0050] Hereinbelow, the experiment is conducted with a light source having wavelength of 650 nm.
[0051] The reflectance and transmittance of the produced disk measured by a spectrophotometer results in (Rc 0 , Ra 0 , Tc 0 , Ta 0 )=(0.3%, 0.3%, 91%, 77%) for the L 0 single layer, and (Rc 1 , Ra 1 )=(22.2%, 3.5%) for the L 1 single layer. Two layers are combined by the resin. A thickness of the resin layer, i.e., a spacer layer, is about 50 Am.
[0052] The drive reflectance of the dual-layered medium is (Rc 0 , Ra 0 , Rc 1 , Ra 1 )=(15.6%, 4.0%, 18.4%, 2.9%). The reflectance of the L 0 is different from reflectance observed by spectrophotometer because the optical property of the dye changes by focusing the light spot to the L 0 . From the calculation, the absorption of the dye with the above-described L structure with respect to the light with 650 nm wavelength is close to 0%. However, the optical property of the dye still changes. The reason for this is that the recording film absorbs the light and transfers the heat to the dye. In the experiment, when the thickness of the upper protective layer exceeds 50 nm, a change in the optical property becomes significantly small.
[0053] Recording is made to the medium. By using an 8-16 modulation code, random mark is recorded by a shortest mark length 0.42 μm and linear velocity of 8.2 m/s. At the L 0 , jitter was 8.2% for the first recording, and 8.6% after overwriting 1000 times, and at the L 1 , jitter was 7.5% for the first recording, and 8.0% after overwriting 1000 times.
[0054] Embodiment 3
[0055] As a layer 104 in FIG. 1, garnet is used. The material used herein is yttrium ion garnet (YIG) having Ga doped therein, and a film thereof is formed by sputtering. A laminated structure of L 0 is polycarbonate substrate of 120 mm in diameter (90 μm)/a protective layer/a recording film InSe (14 nm)/a protective layer/garnet(15 nm). A laminated structure of L 1 is a protective layer/a recording film InSe (16 nm)/a protective layer/a reflective film (80 nm)/120 mm diameter polycarbonate substrate (1.1 mm) The substrate of the medium has grooves with a depth of about 25 nm and a width of 0.16 μm, with a pitch of 0.32 μm.
[0056] The production method of the medium is the same as the method shown in FIGS. 3A to 3 G. Garnet is sputtered in 100% Ar atmosphere (except remnant gases).
[0057] Hereinbelow, the experiment is conducted with a light source having wavelength of 400 nm, and recorded on the groove.
[0058] The reflectance and transmittance of the produced disk measured by a spectrophotometer result in (Rc 0 , Ra 0 , Tc 0 , Ta 0 )=(4.1%, 10.7%, 76.3%, 59.4%) for the L 0 single layer, and (Rc 1 , Ra 1 )=(34.3%, 8.9%) for the L 1 single layer. A thickness of a spacer layer is about 25 μm.
[0059] The drive reflectance of the dual-layered medium is (Rc 0 , Ra 0 , Rc 1 , Ra 1 )=(16.3%, 1.3%, 16.8%, 4.4%). By using an 8-16 modulation code, a random mark is recorded by a shortest mark length 0.19 μm and linear velocity of 6 m/s. At the L 0 , jitter is 7.8% for the first recording, and 8.4% after overwriting 1000 times, and at the L 1 , jitter is 9.0% for the first recording, and 9.5% after overwriting 1000 times.
[0060] Embodiment 4
[0061] As a layer 104 in FIG. 1, ZnMnTe, one of magnetic semiconductor, is used, and a triple-layered rewritable medium is formed. A laminated structure of L 0 is polycarbonate substrate of 120 mm in diameter (90 μm)/a protective layer/a recording film InSe (10 nm)/a protective layer/ZnMnTe (10 nm). A laminated structure of L 1 is a protective layer/a recording film InSe (10 nm)/a protective layer/ZnMnTe (10 nm). A laminated structure of L 2 is a protective layer/a reflective film (80 nm)/120-mm-diameter polycarbonate substrate (1.1 mm). The substrate of the medium is an In Groove substrate having grooves with a depth of about 25 nm and a width of 0.16 μm, with a pitch of 0.32 μm.
[0062] Since the medium is triple-layered, it has a structure as shown in FIG. 5. The production method of the medium is the same as the method shown in FIGS. 3A to 3 G, except that a method shown as FIGS. 3C to 3 E is added after the method in FIG. 3E. ZnMnTe is sputtered in 100% Ar atmosphere (except remnant gases).
[0063] Hereinbelow, the experiment is conducted with a light source having wavelength of 400 nm.
[0064] The reflectance and transmittance of the produced disk measured by a spectrophotometer result in (Rc 0 , Ra 0 , Tc 0 , Ta 0 )=(2.4%, 6.6%, 82.8%, 67.1%) for the L 0 single layer, (Rc 1 , Ra 1 , Tc 0 , Ta 0 )=(1.4%, 3.6%, 82.8%, 67.5%) for the L 1 single layer, and (Rc 2 , Ra 2 )=(23%, 1.5%) for the L 2 single layer. The thickness of a spacer layer is about 20 μm.
[0065] The drive reflectance of the dual-layered medium is (Rc 0 , Ra 0 , Rc 1 , Ra 1 , Rc 2 , Ra 2 )=(10.7%, 1.8%, 10.8%, 3.2%, 10.8%, 0.7%). By using an 8-16 modulation code, random marks are recorded by a shortest mark length 0.19 μm and linear velocity of 6 m/s. Jitter is 9.0% for L 0 , 9.5% for L 1 , and 8.8% for L 2 for the first recording, and 10.1% for L 0 , 10.8% for L 1 , and 9.9% for L 2 after overwriting 1000 times. The jitter obtained herein is a little too high for a practical used. By applying PRML (Partial Response Most Likelihood) as one of the signal process for reading, a data error rate is reduced to about 2×10 −15 .
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In a multilayered optical disk having n layers of recording layers, it is designed in such a manner that transmittance T i of the i th layer from a light-incident side fulfills
∏ i = 1 j - 1 T i 2 ≥ n - j + 1 n
when the light is focused on a recording film of the j th layer. By doing so, the recording/reading property of a multilayered medium is improved.
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CROSS-REFERENCE TO RELATED APPLICATION
The present application is a divisional of U.S. application Ser. No. 07/825,913, filed on Jan. 27, 1992, issued as U.S. Pat. No. 5,258,021.
1. Field of the Invention
The present invention is in the field of heart valve implantations. More particularly, the present invention is directed to the permanent implantation of a prosthetic ring in the annulus of human sigmoid valves (aortic or pulmonary) to remodel them so as to make the valve competent and avoid its replacement with an artificial heart valve. The present invention is also within the surgical field of heart valve reconstruction or repair.
3. Brief Description of the Prior Art
Heart valves are deformed by a variety of pathological processes. The vast majority of the patients have their valves replaced by artificial valves which are of two main types: 1) The "mechanical" valves, made of metal or plastic material, and 2) The "tissue" valves made from animal tissue. These tissue valves use bovine pericardium or a porcine aortic valve which is chemically treated and supported by suturing it to a stent or frame that simplifies its insertion into the annulus of the patient after excision of the diseased aortic or pulmonary valve. These have been termed "bioprosthesis". Several stents for the support of tissue valves have been described and/or patented:
Sugie et. al. (J Thorac Cardiovasc Surg 57:455, 1969. "Clinical experience with supported homograft heart valve for mitral and aortic replacement") describes a support stent that has a circular base with three vertical single posts. The stent is cloth covered so that a tissue aortic valve can be sutured on its inner aspect. The stent cannot be placed at the level of the aortic valve of a patient without previously excising it. Its flat base in a single plane cannot adapt to the curvatures of the patient's own leaflet insertions and therefore cannot be introduced inside the aortic valve. It is designed for mounting a tissue valve in its interior.
W. W. Angell, U.S. Pat. No. 3,983,581, describes a "stent for a tanned expanded natural tissue valve". The stent comprises a frame whose interior configuration is the anatomical negative of the exterior configuration of a tanned expanded aortic tissue valve. The described device can only be placed on the exterior of an aortic valve and not inside because it would interfere completely with the normal movements of the three leaflets.
A Carpentier and E. Lane, U.S. Pat. No. 4,451,936, describe "an aortic prosthetic valve for supra-annular implantation comprising a valve body of generally annular configuration and a valve element movable". "The valve body terminates in a generally annular base and a scalloped suture ring . . . which fit the contour of the sinuses of valsalva at the base of the aorta". This device, although it conforms better to the anatomy of the aortic annulus, cannot be placed inside the aortic root without excising the patient's own aortic valve. Its suturing base requires excision of the three leaflets. It is not designed to be used as an annuloplasty device but as a valve replacement.
D. N. Ross and W. J. Hoskin, U.S. Pat. No. 4,343,048 describe a stent for holding in its interior a tissue valve "for the replacement of defective cardiac valves". "The non viable valve is mounted within". The stent design is such that it cannot be placed within the aortic root without excising the patient's native valve. A feature described to be important in this patent is the flexibility of the stent in order to reduce the stress on the mounted tissue valve.
A. Carpentier and E. Lane, U.S. Pat. No. 4,106,129, describe a new bioprosthetic heart valve that is supported by a wire frame with U shaped commissural support. This support frame supports a preserved porcine xenograft or xenografts from other species, or an allograft (homograft). This patent does not mention using this support frame for remodelling the diseased annulus of a native aortic valve, nor is this structure adapted for such remodelling. This follows, when the general shape of the wire frame shown and described in this patent is considered. The commissure supports are parallel, the base is flat and the inflow and outflow orifices are similar. This structure is obviously designed for supporting a tissue valve but not for being implanted inside an aortic root without previously removing the three native leaflets.
All artificial or prosthetic heart valves, whether mechanical or bioprosthesis, although greatly improving the condition of the patient, have some serious drawbacks, namely: thrombogenicity (tendency towards thrombus formation and subsequent detachment with embolization) and limited durability secondary to mechanical or tissue structural failure.
Other complications such as noise, hemolysis (destruction of blood elements), risk of endocarditis (valve infection) and partical dehiscence of the valve also occur. Because of the risk of embolism, the majority of patients who receive artificial heart valves need to take anticoagulative medication for life with the concomitant risk of hemorrhage and necessary change in life style.
Different and more recent developments in the field of cardiac surgery included attempts to surgically repair diseased heart valves. A variety of surgical maneuvers or procedures have been used for this purpose. This type of reconstructive heart valve surgery has been shown to be far superior to valve replacement. References to such reconstructive heart valve surgery can be found, for example, in the following articles: Angell WW, Oury JH, Shah P: A comparison of replacement and reconstruction in patients with mitral regurgitation. J Thorac Cardiovasc Surg 93:665, 1987; and Lawrence H. Cohn, M.C., Wendy Kowalker, Satinder Bhatia, M.D., Verdi J. DiSesa, M.D., Martin St. John-Sutton, M.D., Richard J. Shemin, M.D., and John J. Collins, Jr., M.D.: Comparative Morbidity of Mitral Valve. Repair versus Replacement for Mitral Regurgitation with and without Coronary Artery Disease. Ann Thorac Surg 45:284-290, 1988.
Reconstructive surgery, however, is difficult to perform and is not always possible in every patient. Among the variety of reconstructive maneuvers, valve annuloplasty is the most frequently performed in the tricuspid and mitral valves. Valve annuloplasty is an operation which selectively reduces the size of the valve annulus. For this purpose, a number of prosthetic rings have been developed for the atrioventricular valves and are used in an increasing number of patients all over the world. The best known commercially available rings are the Carpentier (distributed by Edwards Labs) and the Duran (distributed by Medtronic Inc.) rings. These are described in the following references: Carpentier A, Chauvaud S, Fabiani JN, et. al.: Reconstructive surgery of mitral incompetence: ten year appraisal. J Thorac Cardiovasc Surg 79:338, 1980; Duran CG, Ubago JL: Clinical and hemodynamic performance of a totally flexible prosthetic ring for atrioventricular valve reconstruction. Ann Thorac Surg 22:458-63, 1976; and Duran CG, Pomar JL, Revuelta JM, et. al.: Conservative operation for mitral insufficiency: critical analysis supported by postoperative hemodynamic studies in 72 patients. J Thorac Cardiovasc Surg 79:326, 1980.
The Carpentier and Duran rings, however, can only be used in the mitral and tricuspid valves. It is surprising that although many stents for supporting aortic tissue valves (bioprosthesis) have been described and patented (vide Supra) none has been even suggested as a possible aortic annuloplasty ring. In fact their design make it impossible to be used for this purpose. According to the best knowledge of the present inventor, to date there has been no description nor use of a prosthetic ring for annuloplasty of sigmoid valves (aortic or pulmonary).
Furthermore, an important number of patients develop a pathological dilatation (aneurysm) of the ascending aorta which requires its replacement, particularly when a tear occurs (dissection). This dilatation of the aorta also involves the aortic valve annulus, giving rise to an insufficiency due to lack of coaptation of the valve leaflets, which are otherwise normal. The prior art solution to this problem has been the replacement of the ascending aorta with an implanted artificial "valved conduit". Such a "valved conduit" comprises a biocompatible cloth tube provided with an artificial (mechanical or tissue) valve. Mere replacement of the aorta with a "valveless" artificial conduit while leaving the natural valve in place, is not generally recommended in the art, due to the dilated nature of the valve annulus and due to the danger of further dilation of the unsupported annulus. However, it is also generally recognized in the art that implantation of "valved conduits" raises risks at least of the same complications as other valve replacements.
In view of the foregoing, and to avoid the above noted disadvantages, there is a genuine need in the prior art for a better approach to the treatment of aortic or pulmonary insufficiency. The present invention provides such a better approach.
SUMMARY OF THE INVENTION
The basic and general object of the present invention is to provide a structure that maintains the aortic or pulmonary sigmoid valves in normal shape, or induces such valves to regain their normal shape.
More specifically, when performing a sigmoid valve annuloplasty, the object of the present invention is to implant a device which reduces, to the desired size, the circumference of the diseased aortic or pulmonary valve. This is achieved by the permanent implantation of a prosthetic ring which has the shape of the annulus of the sigmoid valves (aortic or pulmonary) and which, when properly sized, reduces the sigmoid valve circumference, making possible contact of the native valve leaflets. Thus, as a result of the implantation, the native valve becomes competent again.
The invention comprises a stent, circular in shape from above and below, but scalloped so as to follow the contours of each of the three sinuses of the natural heart valve. These sinuses are sometimes referred to in the anatomical art as "sinuses of Valsalva". The stent therefore has three curved "sinusoidal" struts and three round bases, all in continuity.
The stent which in one preferred embodiment comprises biocompatible solid metal single wire, plastic or reabsorbable polymer structure, has a wider diameter at its base than at its upper end, assuming in this respect, the general configuration of a truncated cone. The height of the three "sinusoidal" struts and the distance between their ascending and descending limbs varies with the diameter of the ring. To fit various patients a number of different size rings are required, their base or inflow orifice diameters ranging from 15 to 35 mm.
For implantation the stent is covered with biocompatible cloth. The use of such cloth or fabric mesh to enclose various plastic and/or metal members which are subsequently surgically implanted in the human body is, per se, known in the art. This mesh or cloth, in accordance with standard practice in the art, is relatively thin, preferably it is approximately 0.3 mm thick.
In another preferred embodiment the ascending and descending sinusoidal struts of the described stent are solid but interrupted at the level of the upper and lower connecting curves. Continuity is established by the biocompatible strut covering cloth which stretches from one strut to the next one. In this fashion the general configuration of the stent is maintained. The lower (inflow) and upper (outflow) circumferences remain similar while a certain degree of mobility of each part of the stent is possible.
In order to use the stent in cases where not only the aortic valve is incompetent but also the ascending aorta is pathologically dilated, a valveless conduit is fashioned to be attached to the stent. For this purpose a cloth tube of the type already known in the art, made of biocompatible material which is used for vascular substitution, is formed at one of its ends in a scalloped fashion to follow the contours of the sinusoidal stent, and is sutured to the stent. In one embodiment, the tube has a substantially constant diameter. In another embodiment the tube is shaped so as to form between each strut of the stent a sinus or bulge. A sewing ring or skirt is incorporated at this extremity to permit the suturing, by the surgeon, of the "valveless conduit" to the patient.
The objects and features of the present invention are set forth in the appended claims. The present invention may be best understood, together with further objects and advantages, by reference to the following description, taken in connection with the accompanying drawings:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a lateral view of the preferred embodiment of the solid stent of the present invention, showing the stent as a flat pattern;
FIG. 2 is a lateral view of the preferred embodiment of the solid stent, showing the relationship of its height to diameter and the difference between the "inflow" and "outflow" diameters;
FIG. 3 is a top view of the preferred embodiment of the solid stent, showing again the difference between the inflow (outer) and outflow (inner) diameters;
FIG. 4 is a perspective view of the preferred embodiment of the stent with the relative measurements of each of its parts in relation to the inflow diameter.
FIG. 5 is a perspective view of the preferred embodiment with the cloth covering showing the cloth flanges for holding the anchoring sutures.
FIG. 6 is a schematic view of the patient's aortic valve before and after annuloplasty with the "Sigmoid Annuloplasty Ring".
FIG. 7 is a schematic view of the patient's aortic root during systole and diastole after implantation of the "Sigmoid Annuloplasty Ring".
FIG. 8 is a schematic view of the patient's aortic root after ring annuloplasty (A) compared with after bioprosthesis replacement (B).
FIG. 9 is a schematic depiction of an opened sigmoid (aortic or pulmonary) valve (human or animal) showing the three native tissue leaflets and the annuloplasty ring (stent) of the present invention, placed inside the vessel without interference with the three normal leaflets and held to the arterial wall by a continuous suture.
FIG. 10 is a lateral view of the second preferred embodiment of the stent of the present invention showing the stent in a flat pattern with the solid struts joined by the cloth cover.
FIG. 11 is a top view of the second preferred embodiment of the stent showing the solid struts joined by the cloth cover.
FIG. 12 is a perspective view of a first preferred embodiment of an aortic valveless conduit in accordance with the present invention, and incorporating the stent of the present invention;
FIG. 13 is a perspective view of a second preferred embodiment of an aortic valveless conduit in accordance with the present invention, and incorporating the stent of the present invention and a vascular tube with sinuses of Valsalva;
FIG. 14 is a cross-sectional view of the first preferred embodiment of the aortic valveless conduit, the cross-section being taken on lines 12A,12A of FIG. 12;
FIG. 15 is a cross-sectional view of the second preferred embodiments of the aortic valveless conduit, the cross-section being taken on lines 13B,13B of FIG. 13;
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following specification taken in conjunction with the drawings, sets forth the preferred embodiments of the present invention. The embodiments of the invention disclosed herein are the best modes contemplated by the inventor for carrying out his invention in a commercial environment although it should be understood that various modifications can be accomplished within the parameters-of the present invention.
Referring now to the drawing Figures, and particularly to FIGS. 1-3, the preferred embodiment of the sigmoid valve annuloplasty ring 1 of the present invention is disclosed. It should be noted at the outset that although the ensuing description is primarily directed to the use of the annuloplasty ring 1 in the aortic valve area, the invention is not so limited. Rather, the annuloplasty ring 1 can be also applied to the other sigmoid valve of the human (or animal) anatomy, namely to the pulmonary valve.
Referring now specifically to FIG. 1, an important feature of the present invention is the configuration or shape of the stent of the annuloplasty ring 1. Specifically, the oval stent 1 of the invention has a shape adapted to follow the contour of the normal sigmoid valve. The stent 1 in the first preferred embodiment is constructed from a single solid piece of biocompatible metal. A preferred metal for the stent is titanium or titanium alloy, normally used for implantation. This alloy has very good properties for the present purpose, as well as combining strength with lightness, it is biocompatible.
Biocompatible non-absorbable plastic materials can also be used for the stent, although they would probably need to be thicker than metal, in order to have sufficient strength. Another alternative is the use of biocompatible polymers that are reabsorbed by the organism after a certain time after their implantation.
The solid single piece 2 of the first preferred embodiment of the stent 1 is shaped into the herein described configuration, which is depicted in FIGS. 1, 2, 3 and 4.
The stent 1 has a circular appearance of configuration, when it is viewed from the top or bottom, as is shown on FIG. 3. The "circle" 3 on the bottom represents a wider "inflow" orifice, and the "circle" 4 on the top represent a smaller "outflow" orifice. Thus, as is shown in the drawing figures (principally FIGS. 1-4) the stent forms a "convoluted ring" having three substantially sinusoidal struts 5 which project upwardly from the base "diameter" of the convoluted ring. The ring itself is curved both at its lower (inflow) and upper (outflow) ends so that if placed on a horizontal plane it would only make contact in three points. Each strut has a separate descending and an ascending portion 5 which are generally nonparallel relative to one another. These ascending and descending limbs 5 are joined by smooth curved upper 6 and lower 7 portions (FIGS. 1, 2, 3, 4). These joining parts are curved both in the frontal or lateral and axial view (FIGS. 1, 2 and 3). The angle formed by the ascending and descending limbs 5 in relation to the vertical is substantially 10° (FIGS. 1 and 2).
Proportions between the height and width of the stent can be varied, for as long as the stent meets its stated objective to reduce the circumference of a diseased annulus to its substantially normal size, and to permit the native valve leaflets to seal against each other as shown in FIG. 4. An exemplary-stent 1 depicted in the drawings has the following dimensions: the diameter of the lower "inflow" orifice circle 3 is 20 mm, the diameter of the upper "outflow" orifice circle 4 is 15 mm, the total height 8 of the stent 1 is 15 mm, and the radii of the "turns" of the stent 10 form the sinusoidal struts are 1.5 mm for the upper 6 and 6.5 mm for the lower 7 curve. Those skilled in the art will recognize that the foregoing dimensions and proportions can be varied within certain limits; nevertheless preferably the proportions described above and shown in the drawings are maintained. Limits of the dimensions are to be construed in this regard to be such, that the stent of the invention must approximate the natural shape of the normal heart valve. With respect to the actual "inflow" and "outflow" diameters of the stent 1 (as opposed to relative proportions), the stent 1 of the invention must be manufactured in different sizes to accommodate the different sizes of the human sigmoid valve, which itself varies for each individual. An approximate range of such sizes is between 15 to 35 mm for the inflow diameters. Dimensions of a number of examples of stents constructed in accordance with the invention to fit different patients, are given in FIG. 4.
For implantation the stent 1 is covered with biocompatible cloth. In this regard biocompatible cloth comprises a fabric mesh of biocompatible material, preferably polyester (polyacetate) fabric. The use of such biocompatible fabric mesh to enclose various plastic or metal members which are subsequently surgically implanted in the human body is well known in the art. As is further known, after implantation into the human body, an ingrowth of fibrous tissue usually forms in the interstitial spaces of the fabric, and endothelial cells cover the fabric to provide a nonthrombogenic autologous surface. Therefore, at least sometime after the implantation, the cloth covered metal or plastic member no longer causes coagulation of blood and presents no significant danger of thrombus formation when implanted in the heart.
In accordance with the present invention, the stent 1 is totally covered with this thin fabric, preferably of approximately 0.3 mm thickness, so that there are no plastic or metal surfaces exposed to come into contact with tissue or blood flow. The biocompatible cloth cover of the stent is best illustrated in FIGS. 4 and 5. Different modes of covering the stent are: (a) either by a single layer of cloth 9 in FIG. 4 that fits exactly the shape, thickness and dimensions of the stent, or (b) by doubling the cloth at the lowest and highest points of curvature of the sinusoids of the stent (10 and 11 in FIG. 5). The object of these flanges 10 and 11 is to simplify the identification by the surgeon of these points where the initial anchoring sutures must be placed. Six such sutures placed at the highest 10 and lowest 11 curvatures of the ring must coincide with a point above each commissure and at the lowest point of each sinus of Valsalva of the patient. It is important to avoid contact of the ring with any of the patient's own leaflets, as depicted in FIGS. 6 and 7 which show the mechanism of action of the present invention (FIG. 7) and how it does not interfere with the movements of the patient's sigmoid valve leaflets during the cardiac cycle (FIG. 8). Closure of the sigmoid valve returns to normal by leaflet apposition because of the reduction in the valve annulus induced by the ring. Thus, patients having an implant of the fabric covered stent 1 of the present invention may be gradually weaned from anti-thrombogenic medication, at least some time after the implantation. To emphasize, this is because, as soon as the cloth covered prosthesis (annuloplasty ring) is covered by human tissues, there are no exposed thrombogenic surfaces in the prosthesis and no further danger of embolus formation.
It is emphasized in connection with the annuioplasty ring or prosthesis of the invention, that it is not intended to serve as a heart valve prosthesis, nor as a stent for heart valve prosthesis. Rather, the present invention is an annuloplasty ring, a prosthesis which is to be implanted into the heart to function together with the native heart valve.
The second preferred embodiment of the sigmoid ring 12 is depicted in FIGS. 10 and 11. In this preferred embodiment the struts 13 are made of solid material with the same configuration as in the first preferred embodiment (5 in FIGS. 1, 2, 3 and 4). However these struts 13 are interrupted at the level of the highest curvature 14 and lowest curvature 15 corresponding to 6 and 7 in the first preferred embodiment. Continuity of the stent 12 is re-established by the cloth covering 16 of the stent 12 which fits exactly over the ascending and descending solid limbs 13. In this second preferred embodiment there is no need for constructing cloth flanges for simplifying the suturing of the ring as shown at 10 and 11 in FIG. 5 of the first embodiment. In this second embodiment the anchoring sutures of the sigmoid annuloplasty ring can be passed without difficulty through the cloth at 14 and 15.
Referring now to FIGS. 12 and 13, a first embodiment and a second embodiment 18 of a valveless conduit are disclosed, each of which incorporates the novel annuloplasty ring or stent of the present invention. The valveless conduits are used when, in addition to remodelling of the aortic annulus, a portion of the ascending aorta must also be replaced because it is pathologically dilated.
As shown on FIGS. 12, 13, 14 and 15, the valveless conduit includes the stent 1 of the present invention, which is covered by biocompatible cloth or fabric 19. A cloth tube 20 of biocompatible material and of the type which is used in the state-of-the-art vascular substitutions is attached (by stitching or like means) to the stent 1. For this purpose, one end of the cloth tube 20 is formed (cut) in a scalloped fashion so as to conform to the configuration of the stent 1, and be attachable thereto. In accordance with the first preferred embodiment 17 of the valveless conduit, the cloth tube attached to the stent 1, as is shown on FIGS. 12 and 14, has a substantially constant diameter. In accordance with the second preferred embodiment 18 of the valveless conduit, the cloth tube 20 is configured to form between each strut 21 of the stent 1 a sinus or bulge 22 so as to duplicate the naturally occurring three sinuses of the heart valve (ginuses of Valsalva). A sewing ring or skirt 23 is also attached to the stent 1, or forms part of the cloth cover of the stent 1, to permit attachment by suturing of the valveless conduit to the remnants of the aortic wall of the patient. The sewing ring 23 requires no further detailed description here because it can be constructed in accordance with the state-of-the-art from the same materials which are used for sewing rings utilized in connection with mechanical and tissue heart valves.
Several modifications of the above described novel annuloplasty prosthesis and of the associated part and processes may become readily apparent to those skilled in the art in light of the above disclosure. Therefore, the scope of the present invention should be interpreted solely from the following claims, as such claims are read in light of the disclosure.
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A sigmoid heart valve annuloplasty prosthetic ring is disclosed which has a biocompatible stent molded into a scalloped shape, having three sinusoidal struts, to adapt to the anatomical shape of the annulus of the human sigmoid valves. The prosthetic ring is covered with biocompatible cloth. The prosthetic ring can be incorporated into the extremity of a biocompatible tubular cloth which serves as a vascular prosthesis in order to permit the total replacement of the ascending aorta or pulmonary artery without replacing the sigmoid valve.
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[0001] This is a divisional of application Ser. No. 09/904,829, filed on Jul. 12, 2001, which is a continuation of application Ser. No. 08/939,321, filed on Sep. 29, 1997, and claims priority thereof.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the present invention pertain to the field of video conferencing. More particularly, the embodiments pertain to algorithms for near-lossless digital video compression.
[0004] 2. Background of the Related Art
[0005] A video signal comprises a sequence of frames or images which when displayed at a given frame rate (e.g., 15 to 30 frames per second) simulates the appearance of motion to a human observer. Each frame of the video image comprises a matrix of picture elements, known as “pixels” or “pels.” A pixel is the minimum unit of the picture which may be assigned a luminance intensity and a color. In a computer, depending on the data format used, as many as 3 bytes of data can be used to define visual information for a pixel. One popular data format assigns a luminance intensity represented by 1 byte of data to each pixel and further assigns a color represented by 2 bytes of data to groups of 4 pixels each. This format results in an average use of 12 data bits to represent each pixel. Therefore, a single frame at a resolution of 320×240 can be represented by about 120,000 bytes of data.
[0006] Digital video cameras must transfer frame data to a video memory system for display. Multiple frames are transferred over a period of time. The number of frames transferred and displayed per second is referred to as the frame rate. In general, greater frame rates contribute to heightened appearances of motion, while lower frame rates contribute to the observer being able to perceive individual frames, thus destroying the appearance of motion. A frame rate of 15 frames per second (fps) with a resolution of 320×240 and each pixel being represented by an average of 12 bits requires that about 14 Mbits of data must be transferred between the digital video camera and the video memory each second.
[0007] Digital video cameras are typically connected to a computer system via a peripheral bus. One peripheral bus that is gaining wide acceptance in the computer industry is the Universal Serial Bus (USB). The USB data transfer rate of 8 Mbits/second supports a wide variety of desktop peripherals, from modems, printers, microphones and speakers to graphics tablets, game controls, joysticks, scanners, and digital cameras. However, the USB data rate of 8 Mbits/second is insufficient to support a frame rate of 15 fps for 320×240 video. Further, since several devices may reside on the USB, it is desirable that a digital camera not use the entire 8 Mbits/second.
[0008] Data compression allows an image or video segment to be transferred and stored in substantially fewer bytes of data than required for uncompressed frames. Many methods of digital video compression are based on the idea of eliminating redundant information from frame to frame in a digitized video segment. This is referred to as “interframe compression.” Interframe compression methods exploit the temporal redundancy that exists between digital video frames from the same scene recorded moments apart in time. This reduces the required data needed to encode each frame.
[0009] Interframe compression is not ideally suited to the USB environment. This is due to the fact that the USB architecture will not guarantee that every frame of digital video data will be transferred. It is possible that some frames may be dropped. Since interframe compression techniques depend on frame-by-frame redundancies, dropped frames can have a significant impact on picture quality. Therefore, it is desirable to provide a method and apparatus for compressing digital video images that will allow digital cameras to operate on peripheral busses such as the USB.
[0010] Further, it is desirable to provide a method and apparatus for compressing digital video images that is not perceived as “lossy” by the human visual system. Video compression techniques that humans perceive as “lossy” do not fully preserve all the information originally captured in an image. In general, for “lossy” techniques, as the compression of the video data is increased, the quality of the video suffers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1 shows a flow chart of a method for encoding data representing a component of a picture element implemented in accordance with one embodiment of the invention.
[0012] [0012]FIG. 2 depicts a flow chart of a method for encoding data representing a component of each picture element of a digital image implemented in accordance with one embodiment of the invention.
[0013] [0013]FIG. 3 shows data representing two scan lines from an example Y-plane of a frame of digital video.
[0014] [0014]FIG. 4 depicts an example quantization table implemented in accordance with one embodiment of the invention.
[0015] [0015]FIG. 5 a illustrates a high quality, 4-bit encoding example implemented in accordance with one embodiment of the invention.
[0016] [0016]FIG. 5 b depicts an example decoding result from the high quality, 4-bit encoding example illustrated in FIG. 5 a implemented in accordance with one embodiment of the invention.
[0017] [0017]FIG. 6 a illustrates a high compression, 3-bit encoding example implemented in accordance with one embodiment of the invention.
[0018] [0018]FIG. 6 b depicts an example decoding result from the high compression, 3-bit encoding example illustrated in FIG. 6 a implemented in accordance with one embodiment of the invention.
[0019] [0019]FIG. 7 shows an example computer system including an imaging device implemented in accordance with one embodiment of the invention.
[0020] [0020]FIG. 8 a depicts an example 4-bit encode table with no under-correction implemented in accordance with one embodiment of the invention.
[0021] [0021]FIG. 8 b depicts an example 4-bit encode table with 50% under-correction implemented in accordance with one embodiment of the invention.
[0022] [0022]FIG. 8 c depicts an example 4-bit decode table implemented in accordance with one embodiment of the invention.
DETAILED DESCRIPTION
[0023] A method and apparatus for near-lossless digital video compression is disclosed. In the following description, for the purposes of explanation, specific details are set forth to provide a thorough understanding of the invention. However, it will be obvious to one skilled in the art that these specific details are not required to practice the invention. In other instances, well known methods, devices, and structures are not described in particular detail in order to avoid obscuring the invention.
[0024] Overview
[0025] The invention solves the problem of providing digital image compression that results in an ordinary viewer of the resulting image perceiving the image as “non-lossy” and further that does not rely on interframe redundancies, thereby allowing high quality digital video signals to be transferred across a peripheral bus such as the USB. The invention accomplishes this by using a compression method that takes advantage of redundancies between two scan lines within a given frame of digital video. The compression algorithm of the invention uses Differential Pulse Code Modulation (DPCM) with varying levels or tables of quantizers. In general, and in accordance with one embodiment of the invention, a difference is calculated between a first sample from a current scan line and a corresponding second sample from a previous scan line. A quantization table level is selected from a quantization table that includes at least one level, and information identifying the selected level is placed into an information stream. A quantizer is selected from the quantization table level based on the calculated difference and information corresponding to the selected quantizer is place into the information stream.
[0026] The invention provides “near-lossless” digital image compression. The term “near-lossless” as used herein means that while some information corresponding to an image is not preserved during the compression process, an ordinary viewer of the resulting decoded and displayed image would not notice any degradation in quality.
[0027] One Embodiment of the Invention
[0028] For this embodiment, each picture element has a luminance intensity component (the Y component) and two color components (the C R and C B components). The totality of Y components for a given frame is referred to as the Y plane for that frame. Likewise, the totality of the C R and C B components for a given frame can be referred to as C R and C B planes, respectively. These luminance and color components conform to the International Telecommunications Union-Radio Sector (ITU-R) BT.601 standard. Other video color systems, such as RGB, may also be used with the invention.
[0029] [0029]FIG. 1 shows a flow chart of a method for encoding data representing a component of a picture element implemented in accordance with one embodiment of the invention. At step 110 , a difference is calculated between a sample value for a picture element from a current scan line and a sample value for a picture element from a previous scan line.
[0030] Following step 110 , a quantization table level is selected at step 120 . The quantization table may include any number of levels, with each level including any number of quantizers. An example quantization table is shown in FIG. 4, discussed below. The level selection is based on the value of the calculated difference.
[0031] If the selected level differs from a previously selected level, a level switch occurs. This determination is made at step 125 . The term “level switch” is more fully discussed below in connection with FIG. 2. If there is a level switch, information identifying the selected level is placed into an information stream at step 130 . The information stream may be a bit-stream that is transferred across a peripheral bus such as the USB. The information stream may also include information being transferred across buses with data path widths greater than 1 bit. The information stream is received by a device or system that will perform decoding functions.
[0032] After the information identifying the selected level is placed in the information stream, a quantizer from the selected level is selected at step 140 . The term quantizer as used herein is defined as an index into the quantization table. The quantizer selection is based on the value of the calculated difference. Following quantizer selection, information identifying the selected quantizer is placed in the information stream at step 150 .
[0033] [0033]FIG. 2 depicts a flow chart of a method for encoding data representing a component of each picture element of a digital image implemented in accordance with one embodiment of the invention. For this embodiment, each plane is processed independently, although other embodiments are possible where the planes are not processed independently. The method depicted in FIG. 2 begins with step 202 where the 0 th scan line is sampled. The sample values for scan line 0 are stored in a buffer or some other storage device at step 204 . Next, the sample values are placed in an information stream at step 206 . Note that the 0 th scan line of each plane is not quantized or encoded at all. The 0 th line serves as a predictor for the following scan line, as discussed below.
[0034] Following step 206 is step 208 where the 0 th picture element of the next scan line (line 1 ) is sampled. After sampling the 0 th picture element of scan line 1 , a difference is calculated at step 210 between the sample value of the 0 th picture element of line 1 and the sample value of the 0 th picture element from the 0 th scan line.
[0035] The present embodiment uses a quantization table that has multiple levels. For example, one level may have quantizers ranging in value from 0 to +/−7 while another level may have quantizers ranging in value from 0 to +/−181, as shown in the example quantization table of FIG. 4 which is discussed below. For the present embodiment, a default level, known to both the encoder and decoder, is used at the beginning of each scan line that is encoded. Since the default level is known to both the encoder and the decoder, there is no need to communicate the selection of the default level to the decoder. The invention may also be practiced without a default level. In this case, a level must be selected at the beginning of processing each scan line, and the selection of the new level must be communicated to the decoder.
[0036] Following step 210 , a quantizer is selected at step 214 . The quantizer is selected based on the difference calculated between the sample value of the 0 th picture element of line 1 and the sample value of the 0 th picture element from the 0 th scan line at step 210 . The quantizer is selected from the default quantization table level. Following quantizer selection, information identifying the selected quantizer is placed into the information stream at step 216 .
[0037] Once the sample value of the 0 th picture element has been encoded, that is, after the difference has been calculated and after the quantizer has been selected, the quantizer is decoded and written back to a buffer for use as a predictor by the 0 th element of the next scan line. The decoding occurs at step 218 . The decoding step 218 uses the quantizer to look up a quantization value in the currently selected quantization table level. The quantization value is placed in a buffer or other storage device at step 220 .
[0038] After processing the 0 th picture element of line 1 in steps 208 , 210 , 214 , 216 , 218 , and 220 , the next picture element in the current scan line (presently line 1 ) is processed. The next picture element is sampled at step 222 , and a difference between the sample value of the current picture element and the sample value for the corresponding picture element from the previous scan line is calculated at step 224 .
[0039] At step 226 , a quantization table level is selected. The selection is based on the difference calculated at step 224 . Specific example embodiments of level selection algorithms are discussed below in connection with FIG. 4.
[0040] Following quantization table level selection at step 226 , a determination is made at step 228 on whether a level switch should occur. The term “level switch” as used herein means that a different quantization table level will be used for the current quantizer selection than was used for the previous quantizer selection. The invention may be practiced by allowing level switches every time a level is selected at step 226 , or the invention may be practice by restricting the frequency of level switches. For example, it is possible to only allow level switches every four times a picture element is processed. Thus, a single level is used for at least four contiguous samples before a level switch can occur. Restricting the frequency of level switches has the benefits of reducing traffic on the information stream, helping to providing an adequate compression ratio, and allowing easier and speedier decoding. Further, it is possible to limit the total number of times a level shift can occur for an entire frame. The Y, C R and C B planes can be considered separately or in combination when determining a level shift maximum. As an example, the maximum number of level shifts can be set to equal 10% of the byte size of one raw (uncompressed) video frame, plus one. The plus one is there in order to handle the case where the 10% limit is reached part way through a scan line. The one extra level switch can be used to switch to the default level, and the default level will then be used for the remainder of the frame. Level shift maximums other than 10% are also possible. Further, the level shift maximum may be varied at any time.
[0041] If a determination is made at step 228 that a level switch is required, information identifying the new level is placed into the information stream at step 230 . Step 230 may include placing an escape code into the information stream to let the decoding device know that information identifying a new level follows. Following step 230 is step 232 .
[0042] If no level switch is required or allowed, control passes to step 232 following step 228 . At step 232 , a quantizer is selected from the proper quantization table level and information identifying the selected quantizer is placed into the information stream. Following step 232 , the current sample is decoded at step 234 and the decoded current sample is placed in a buffer or other storage device at step 236 .
[0043] If previous steps 222 through 236 processed the last picture element in the current scan line, then control passes to step 240 . Otherwise, step 222 follows step 238 and another picture element is processed at steps 222 through 236 . These steps are repeated until the final picture element for the current scan line has been processed.
[0044] At step 240 , a determination is made on whether the current scan line is the last scan line in the frame. If the current scan line is the last scan line, then the processing of the frame (or at least one plane of the frame) has completed. Otherwise, the processing of the next scan line begins at step 208 . Steps 208 through 240 are repeated until the last scan line has been processed.
[0045] [0045]FIGS. 3 through 6 b set forth a couple of examples of how the invention may be practiced. FIG. 3 shows an example Y-plane 300 consisting of two scan lines and eight sampled picture elements per scan line. The Y-plane 300 is not intended to represent a realistic sampled Y-plane, but is disclosed in order to provide a simple example. The Y-plane 300 is discussed below in connection with FIGS. 5 a through 6 b.
[0046] [0046]FIG. 4 depicts an example quantization table 400 implemented in accordance with one embodiment of the invention. The table 400 consists of 5 levels with levels 0 through 2 including 15 quantizers each and levels 3 and 4 including 7 quantizers each. One embodiment of the invention has two modes of operation: 1) a high quality, 4-bit encoding mode; and 2) a high compression, 3-bit encoding mode. For table 400 , the quantizers delineated by the dashed line are used for the high quality mode, while the quantizers delineated by the solid line are used for the high compression mode. The quantization values included in the table 400 are examples. It is possible to practice the invention using different numbers of levels, embodying different numbers of quantizers and using different quantizer values.
[0047] The invention may also be practiced with more than one quantization table. It is possible to switch between two or more quantization tables as applications require. For example, one table could be used to provide standard encoding while another is used to provide under correction. Under correction has the effect of both smoothing out quantization noise (the decoded and displayed images look subtly blurred, but this tends to look “better”), and reducing the number of level shifts. One method of applying under correction involves multiplying the differences calculated in steps 210 and 224 in FIG. 2 by a factor of, for example, between 0.5 and 1. Another method of applying under correction is to scale the quantization table values by a factor of, for example, between 1 and 2. A factor of 1 in each method if applying under correction is the same as having no under correction. Thus, one table could be used to provide no under correction while another table could be used to provide under correction. Multiple tables could be used to provide varying degrees of under correction. Further, while one table is being used for encoding, another table may be updated or its values changed.
[0048] One embodiment of the invention also provides a separate decode table. This allows an under correction factor to be applied to the encode table(s) only. Alternatively, the decode table could include the same quantization values as the encode table(s).
[0049] [0049]FIG. 5 a illustrates a high quality, 4-bit encoding example implemented in accordance with one embodiment of the invention. This example uses the example Y-plane 300 shown in FIG. 3 and the quantization table 400 shown in FIG. 4. First, the difference between the 0 th sample of the current line and the 0 th sample of the previous line is calculated. The difference has a value of −1. Next, a “best” level is selected. The method for selecting the “best” level for this example embodiment is as follows:
For all Y-planes data if (absolute value of the calculated difference) < 65 best level = 1; (default level at the beginning of each scan line ) else best level = 2; For all C R and C B plane data if (absolute value of calculated difference) < 8 best level = 0; ( default level at the beginning of each scan line ) else best level = 1.
[0050] Note that level 0 is not used when encoding the Y-plane and level 2 is not used when encoding the C R and C B planes. Also, the present embodiment implements a policy of restricting level shifts to once every four samples. One possibility, implemented in the present embodiment, is to determine the “best” level for four contiguous samples, then use the highest level for all four samples. As mentioned above, the default level for the beginning of each scan line for the Y-plane is level 1. Thus, the first four samples in the present example use level 1.
[0051] Once the “best” level is determined, the difference (−1 in the case of sample 0) is matched to the closest quantization table 400 value. The closest quantization table 400 value for in level 1 for sample 0 is 0. Quantization value 0 corresponds to quantizer 0, thus 0 is output into the information stream. Samples 1 through 3 are likewise processed, with level 1 used in each case.
[0052] For sample 4, the difference between the 4 th sample of the previous scan line and the 4 th sample of the current line is −119. Using the “best” level algorithm disclosed above, the “best” level for the 4 th sample is 2. Note that the highest “best” level for sample 4 through 7 is level 2. Thus, level 2 will be used for samples 4 through 7 . In the present example, an escape code of 15 is placed in the information stream to signal to the decoding device that a new level follows. Thus, a value of 15 followed by a value of 2 are placed into the information stream. The difference of −119 for the 4 th sample matches most closely in level 2 with the quantization value
[0053] −129 which corresponds with quantizer 12. Therefore, a value of 12 is placed into the information stream. Samples 5 through 7 are processed in similar fashion, each using level 2.
[0054] [0054]FIG. 5 b depicts an example decoding result from the high quality, 4-bit encoding example illustrated in FIG. 5 a implemented in accordance with one embodiment of the invention. The values in FIG. 5 b are the result of decoding the information placed into the information stream in the example shown in FIG. 5 a . The decoding table used to determine the values in FIG. 5 b includes the same quantization table values as the table 400 in FIG. 4.
[0055] [0055]FIG. 6 a illustrates a high compression, 3-bit encoding example implemented in accordance with one embodiment of the invention. This example also uses the example Y-plane 300 shown in FIG. 3 and the quantization table 400 shown in FIG. 4. First, the difference between the 0 th sample of the current line and the 0 th sample of the previous line is calculated. The difference has a value of −1. Next, a “best” level is selected. The method for selecting the “best” level for this example embodiment is as follows:
For all Y-plane data if (absolute value of the calculated difference) < 33 best level = 2; (default level at the beginning of each scan line) else if (absolute value of the calculated difference) < 65 best level = 3; else best level = 4; For all C R and C B plane data if (absolute value of calculated difference) < 11 best level = 0; ( default level at the beginning of each scan line ) else if (absolute value of calculated difference) < 21 best level = 1; else best level = 2.
[0056] Note that levels 0 and 1 are not used when encoding the Y-plane and levels 3 and 4 are not used when encoding the C B and C R planes. This example also implements the policy of restricting level shifts to once every four samples, and in particular, the policy of using the highest “best” level for four contiguous samples. As mentioned above, the default level for the beginning of each scan line for the Y-plane is level 2. Thus, the first four samples in the present example use level 2.
[0057] Once the “best” level is determined, the difference (−1 in the case of sample 0) is matched to the closest quantization table 400 value. The closest quantization table 400 value for in level 2 for sample 0 is 0. Quantization value 0 corresponds to quantizer 0, thus 0 is output into the information stream. Samples 1 through 3 are likewise processed, with level 2 used in each case.
[0058] For sample 4, the difference between the 4 th sample of the previous scan line and the 4 th sample of the current line is −119. Using the “best” level algorithm disclosed above, the “best” level for the 4 th sample is 4. Note that the highest “best” level for sample 4 through 7 is level 4. Thus, level 4 will be used for samples 4 through 7. In the present example, an escape code of 7 is placed in the information stream to signal to the decoding device that a new level follows. Thus, a value 7 followed by a value 4 are placed into the information stream. The difference of −1 19 for the 4 th sample matches most closely in level 4 with the quantization value −128 which corresponds with quantizer 6. Therefore, a value 6 is placed into the information stream. Samples 5 through 7 are processed in similar fashion, each using level 4.
[0059] [0059]FIG. 6 b depicts an example decoding result from the high compression, 3-bit encoding example illustrated in FIG. 6 a implemented in accordance with one embodiment of the invention. The values in FIG. 6 b are the result of decoding the information placed into the information stream in the example shown in FIG. 6 a . The decoding table used to determine the values in FIG. 6 b includes the same quantization table values as the table 400 in FIG. 4.
[0060] [0060]FIG. 7 depicts an exemplary computer system 700 including an imaging device 730 having an encoder 740 implemented in accordance with one embodiment of the invention. Computer system 700 typically includes a bus 702 for communicating information, such as instructions and data. The system further includes a processor 704 , coupled to the bus 702 , for processing information according to programmed instructions, a main memory 706 coupled to the bus 702 for storing information for processor 704 , and an information storage device 708 coupled with the bus 702 for storing information. In the case of a desk-top design for computer system 700 , the above components are typically located within a chassis (not shown).
[0061] The processor 704 could be an 80960, 80386, 80486, Pentium{circumflex over ( )} processor, Pentium{circumflex over ( )} processor with MMX™ technology, Pentium{circumflex over ( )} Pro processor or Pentium{circumflex over ( )} II processor made by Intel Corp., among others, including processors that are compatible with those listed above; The processor 704 typically includes a plurality of pipelines for parallel and overlapping execution of operations. The main memory 706 could be a random access memory (RAM) to store dynamic information for processor 704 , a read-only memory (ROM) to store static information and instructions for processor 704 , or a combination of both types of memory. The processor 704 executes instructions that cause the output of the imaging device 730 to be decoded. The processor may either perform calculations in order to decode the output of the imaging device 730 or may use a decode table stored in the main memory 706 . The results of the decoding may be displayed on a display device 710 or stored for later display in the information storage device 708 or in the main memory 706 .
[0062] In alternative designs for the computer system 700 , the information storage device 708 could be any medium for storage of computer readable information. Suitable candidates include a read-only memory (ROM), a hard disk drive, a disk drive with removable media (e.g., a floppy magnetic disk or an optical disk), or a tape drive with removable media (e.g., magnetic tape), synchronous DRAM or a flash memory (i.e., a disk-like storage device implemented with flash semiconductor memory). A combination of these, or other devices that support reading or writing computer readable media, could be used.
[0063] The input/output devices of the computer system 700 typically comprise the display device 710 , an alphanumeric input device 712 , a position input device 714 , a communications interface 716 , and the imaging device 730 , each of which is coupled to the bus 702 . The imaging device may comprise a digital camera. If the data storage device 708 supports removable media, such as a floppy disk, it may also be considered an input/output device.
[0064] The imaging device 730 includes the encoder 740 which comprises an encoder quantization table select register 742 , a level shift maximum register 748 , a scan line buffer 744 , encoder quantization tables 745 and 747 , and a decoder table 749 . The table select register 742 is written to by the processor 704 or other system device in order to select which quantization table is to be used for encoding. The tables 745 and 747 may also be written to by the processor or other system device in order to update the values contained in the tables. Although two encoding tables are shown, any number of encoding tables may be used with the invention. The level shift maximum register 748 is used to store a value that determines the maximum number of level shifts allowed per frame. This register is may also be written to by the processor 704 or other system device. The scan line buffer 744 is used to store at least one previously sampled decoded scan line which is to be used as a predictor for a subsequent scan line. The decoder table 749 is used when decoding scan lines for storage in the line buffer 744 . Example tables that may be used to implement tables 745 , 747 , and 749 are shown in FIGS. 8 a , 8 b , and 8 c.
[0065] It will be clear to one skilled in the art that the invention can operate upon a wide range of programmable computer systems, not just the example computer system 700 .
[0066] [0066]FIG. 8 a depicts an example 4-bit encode table with no under-correction. This example table may be used to implement encoder quantization tables 745 and/or 747 shown in FIG. 7. The table shown in FIG. 8 a uses only absolute values of the calculated difference to be encoded. This example table contains similar information as the table shown in FIG. 4 for 4-bit encoding, but since only absolute values are used, the table is smaller and therefore more efficient to implement in hardware. The absolute difference value must be less than the value in the quantizer (limit) column, with the exception of the “Last” column. The “Last” column contains the upper limits (Max) for the Y, C R and C B planes. Since the “Last” column contains these upper limits, no “less than” test occurs. When an upper limit is reached, the quantizer from the “Last” column is selected. For all of the columns, if the sign of the calculated difference to be encoded is positive, then the appropriate odd numbered quantizer is selected. If the sign of the calculated difference to be encoded is negative, then the appropriate even numbered quantizer is selected.
[0067] [0067]FIG. 8 b shows an example 4-bit encode table that functions in a manner similar to the table depicted in FIG. 8A. The table of FIG. 8 b , however, has 50% under correction applied. Notice that the table values are twice the values contained in the table of FIG. 8 a . This example table may also be used to implement encoder quantization tables 745 and/or 747 shown in FIG. 7. Further, the table of FIG. 8 a may be used to implement one of the tables 745 and 747 while the table of FIG. 8 b may be used to implement the other.
[0068] [0068]FIG. 8 c depicts an example 4-bit decode table that may be used in connection with the tables shown in FIGS. 8 a and 8 b . The present example decode table may be used to implement the decoder table 749 as shown in FIG. 7. The decode table of FIG. 8 c also uses absolute values. If the quantizer to be decoded is an even number, then the sign of the decoded value will be negative. If the quantizer to be decoded is an odd number, then the sign of the decoded value will be positive. If the quantizer to be decoded is zero, then the decoded value will be zero.
[0069] Although the tables discussed above in connection with FIGS. 8 a , 8 b , and 8 c are shown as having particular values, formats, and sizes, the tables may be implemented with varying numbers of levels and quantizers, and may also be implemented with different values. In particular, the tables of FIGS. 8 a , 8 b , and 8 c may be implemented as 3-bit encode or decode tables, and also may implement varying amounts of under-correction.
[0070] In the foregoing specification the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are accordingly to be regarded in an illustrative rather than in a restrictive sense.
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A method and apparatus for video conferencing is disclosed. According to one embodiment, a Universal Serial Bus (USB) enabled digital video camera may output an encoded information stream. The USB-enabled digital video camera including an encoder may compress image data received by the USB-enabled digital video camera during a real-time video conference to produce the encoded information stream in which no frame of the encoded information stream may depend on a previous frame by performing intra frame encoding. A computer system coupled to the USB-enabled digital video camera via a USB may be used to decode the encoded information stream and to transmit the image data to one or more other computer systems as part of a video conferencing data stream.
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RELATED APPLICATIONS
This application is a national stage application (under 35 U.S.C. 371) of PCT/EP2003/012369 filed Nov. 3, 2003 which claims benefit to Great Britain application 0226010.7 filed Nov. 8, 2002.
FIELD OF THE INVENTION
The present invention relates to organic semiconductive polymers comprising aryl substituted trans-indenofluorene repeat units, monomers for the preparation of such polymers, methods for the preparation of such polymers and the use of such polymers in organic optoelectronic devices.
BRIEF DESCRIPTION OF THE PRIOR ART
Semiconductive organic polymers have been known for several decades. During the past ten years they have found increasing application as transistors and in the field of optoelectronic devices including organic photovoltaic devices (in particular solar cells), organic photodetectors and electroluminescent devices, also known as polymeric light emitting devices, see for example WO 90/13148.
A polymeric light emitting device comprises a negative charge carrier injecting electrode, a positive charge carrier injecting electrode and a layer of polymeric light emitting material situated between the two electrodes. Application of a voltage between the two electrodes causes positive charge carriers, known as holes, to be injected from the positive charge injecting electrode and negative charge carriers, electrons, to be injected from the negative charge carrier injecting electrode. The holes and electrons combine in the layer of polymeric light emitting material to form an exciton which decays emitting light. The electroluminescent device may also comprise further layers for the transport of charge carriers from the electrodes to the layer of light emitting polymers, alternatively the light emitting polymer itself may incorporate charge transporting units in addition to light emissive units.
The nature of the polymeric material used in electroluminescent devices is critical to the performance of the device. Materials used include poly(phenylenevinylenes), as disclosed in WO 90/13148, polyfluorenes, as disclosed in WO 97/05184 and poly(arylamines) as disclosed in WO 98/06773. Copolymers and blends of polymers have been found to be useful in such devices, as disclosed in WO 92/03490, WO 99/54385, WO 00/55927 and WO 99/48160. Poly(arylamines) have been disclosed in which the aromatic groups may comprise heteroaromatic moieties such as triazine as disclosed in WO 01/49769. In copolymers and blends of polymers different monomer units are used to provide different functions in the device, namely electron transport, hole transport and light emission.
In particular chains of fluorene repeat units, such as homopolymers or block copolymers comprising dialkylfluorene repeat units, may be used as electron transporting materials. In addition to their electron transporting properties, polyfluorenes have the advantages of being soluble in conventional organic solvents and have good film forming properties. Furthermore, fluorene monomers are amenable to Yamamoto polymerisation or Suzuki polymerisation which enables a high degree of control over the regioregularity of the resultant polymer.
One example of a polyfluorene based polymer is a blue electroluminescent polymer of formula (a) disclosed in WO 00/55927:
wherein w+x+y=1, w≧0.5, 0≦x+y≦0.5 and n≧2.
In this polymer, chains of dioctylfluorene, denoted as Fluorene, function as the electron transport material; the triphenylamine, denoted as TA, functions as the hole transport material and the bis(diphenylamino)benzene derivative, denoted as BTA, functions as the emissive material.
There are a number of disadvantages associated with fluorene based polymers which have led to a search for alternative electron transporting and light emitting units. These disadvantages include the limited hole transporting ability of the fluorene units, the tendency of fluorene units to aggregate and the fact that when blue light emission occurs from fluorene based polymers the emission does not occur in the region of the electromagnetic spectrum in which the human eye is most sensitive.
In an effort to provide alternatives to fluorene based polymers which do not show these disadvantages, light emitting polymers comprising alkyl substituted trans-indenofluorene units (one example is shown below) have been described by S. Setayesh et al. (Macromolecules, 2000, 33, 2016) and others.
These polymers are formed by polymerisation of the corresponding dibromo-monomer in the presence of a nickel catalyst. However, these homopolymers generally show the same disadvantages as described above, namely the tendency to aggregate. Luminescence occurred from aggregates or excimers, resulting in a broad emission band with an emission maximum in the green region. Therefore, these homopolymers are not useful for the generation of blue light. Marsitzky et al. (Advanced Materials, 2001, 13, 1096-1099) describe the supression of aggregate emission by copolymerising tetraoctyl substituted trans-indenofluorene with anthracene resulting in a blue emission. However, after storage at room temperature, the PL efficiency decreases which is attributed to morphology changes facilitating the formation of small amounts of excimer/aggregates. It is therefore obvious that these trans-indenofluorenes are not useful for the stable generation of blue light.
SUMMARY OF THE INVENTION
The present inventors have found that poly(trans-indenofluorenes) that are substituted with at least one aromatic or heteroaromatic group in the 6 and/or 12 position do not show the disadvantages described above. They are therefore suitable for the use in blue light emitting devices. They have further found that these poly(trans-indenofluorenes) are more stable to hole transport than polyfluorenes. In order to provide a range of poly(trans-indenofluorenes) with wider application in light emitting devices the present inventors have found that by providing at least one aryl or heteroaryl substituent on the trans-indenofluorene unit it is possible to provide trans-indenofluorene units with a higher electron affinity and therefore improved electron injecting and transporting properties. A further advantage of such aryl substituted trans-indenofluorene units is that polymers comprising these units have a higher Tg (glass transition temperature) and are therefore more stable and provide longer lived light emitting devices.
Accordingly, in a first aspect the invention provides polymers comprising optionally substituted first repeat units of formula (I):
wherein R 1 , R 2 , R 3 and R 4 are selected from hydrogen, alkyl, alkyloxy, aryl, aryloxy, heteroaryl or heteroaryloxy groups, and R 1 and R 2 and/or R 3 and R 4 may be linked to form a monocyclic or polycyclic, aliphatic or aromatic ring system, provided that at least one of R 1 , R 2 , R 3 and R 4 comprises an aryl or heteroaryl group.
Preferably, alkyl is C 1 -C 20 -alkyl which can be each straight-chain, branched or cyclic, where one or more non-adjacent CH2 groups may be replaced by oxygen, sulphur, —CO—, —COO—, —O—CO—, NR 10 —, —(NR 11 R 12 ) + -A − or CONR 13 —, in particular preferred methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, s-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-octyl or cyclooctyl, and R 10 , R 11 , R 12 , R 13 are identical or different and are hydrogen or an aliphatic or aromatic hydrocarbon radical having 1 to 20 carbon atoms.
Preferably, arylalkyl is C 7 -C 20 -arylalkyl, where one or more non-adjacent CH2 groups may be replaced by oxygen, sulphur, —CO—, —COO—, —O—CO—, NR 10 —, —(NR 11 R 12 ) + -A − or —CONR 13 —, in particular preferred o-tolyl, m-tolyl, p-tolyl, 2,6-dimethylphenyl, 2,6-diethylphenyl, 2,6-di-i-propylphenyl, 2,6-di-t-butylphenyl, o-t-butylphenyl, m-t-butylphenyl or p-t-butylphenyl, and R 10 , R 11 , R 12 , R 13 are identical or different and are hydrogen or an aliphatic or aromatic hydrocarbon radical having 1 to 20 carbon atoms.
Preferably, alkylaryl is C 7 -C 20 -alkylaryl, where one or more non-adjacent CH2 groups may be replaced by oxygen, sulphur, —CO—, —COO—, —O—CO—, NR 10 —, —(NR 11 R 12 ) + -A − or —CONR 13 —, in particular preferred benzyl, ethylphenyl, propylphenyl, diphenylmethyl, triphenylmethyl or naphthalinylmethyl, and R 10 , R 11 , R 12 , R 13 are identical or different and are hydrogen or an aliphatic or aromatic hydrocarbon radical having 1 to 20 carbon atoms.
Preferably, aryl is C 6 -C 20 -aryl, in particular preferred phenyl, biphenyl, naphthyl, anthracenyl, triphenylenyl, [1,1′;3′,1″]terphenyl-2′-yl, binaphthyl or phenanthreny.I
Preferably, heteroaryl is C 5 -C 20 -heteroaryl, in particular preferred 2-pyridyl, 3-pyridyl, 4-pyridyl, chinolinyl, isochinolinyl, acridinyl, benzochinolinyl or benzoisochinolinyl.
Preferably, alkyloxy is C 1 -C 20 -alkyloxy, where one or more non-adjacent CH2 groups may be replaced by oxygen, sulphur, —CO—, —COO—, —O—CO—, NR 10 —, —(NR 11 R 12 ) + -A − or —CONR 13 —, in particular preferred methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy or t-butoxy, and R 10 , R 11 , R 12 , R 13 are identical or different and are hydrogen or an aliphatic or aromatic hydrocarbon radical having 1 to 20 carbon atoms.
Preferably, aryloxy is C 6 -C 20 -Aryloxy, in particular preferred phenoxy, naphthoxy, biphenyloxy, anthracenyloxy or phenanthrenyloxy.
Preferably, arylalkyloxy is C 7 -C 20 -arylalkyloxy where one or more non-adjacent CH2 groups may be replaced by oxygen, sulphur, —CO—, —COO—, —O—CO—, NR 10 —, —(NR 11 R 12 ) + -A − or —CONR 13 —, and R 10 , R 11 , R 12 , R 13 are identical or different and are hydrogen or an aliphatic or aromatic hydrocarbon radical having 1 to 20 carbon atoms.
Preferably, alkylaryloxy is C 7 -C 20 -alkylaryloxy, where one or more non-adjacent CH2 groups may be replaced by oxygen, sulphur, —CO—, —COO—, —O—CO—, NR 10 —, —(NR 11 R 12 ) + -A − or —CONR 13 —, and R 10 , R 11 , R 12 , R 13 are identical or different and are hydrogen or an aliphatic or aromatic hydrocarbon radical having 1 to 20 carbon atoms.
Preferably, alkylthio is C 1 -C 20 -alkylthio where one or more non-adjacent CH2 groups may be replaced by oxygen, sulphur, —CO—, —COO—, —O—CO—, NR 10 —, —(NR 11 R 12 ) + -A − or —CONR 13 — and R 10 , R 11 , R 12 , R 13 are identical or different and are hydrogen or an aliphatic or aromatic hydrocarbon radical having 1 to 20 carbon atoms.
In a preferred embodiment at least two of R 1 , R 2 , R 3 and R 4 comprise an aryl or heteroaryl group. Alternatively at least three of R 1 , R 2 , R 3 and R 4 comprise an aryl or heteroaryl group or each of R 1 , R 2 , R 3 and R 4 may comprise an aryl or heteroaryl group.
In a particularly preferred embodiment R 1 and R 2 comprise an aryl or heteroaryl group and R 3 and R 4 comprise an alkyl group.
Suitable aryl groups include phenyl, substituted phenyl, in particular alkyl substituted phenyl groups such as 4-octyl-phenyl and 4-tert-butyl-phenyl, fluoroalkyl substituted phenyls such as 4-(trifluoromethyl)phenyl, alkoxy substituted phenyl, such as 4-(2-ethylhexyloxy)phenyl and 4-methoxyphenyl, fluorinated phenyls, such as perfluorophenyls and 4-fluorophenyl and aryl substituted phenyls such as 4-(phenyl)phenyl. Suitable heteroaryl groups include pyridine, triazine, thiophene, pyrrole and furan, the heteroaryl groups may be substituted with alkyl, alkoxy, fluoro, fluoroalkyl, aryl or heteroaryl substituents.
Where one of R 1 , R 2 , R 3 and R 4 comprises an alkyl group suitable alkyl groups include octyl, tert-butyl, methyl, hexyl, perfluorooctyl or perfluorohexyl. Where one of R 1 , R 2 , R 3 and R 4 comprises an alkyl group the most preferred alkyl group is octyl.
It is particularly advantageous if the aryl group comprises an optionally substituted phenyl group. 4-Octylphenyl and 4-tert-butyl-phenyl substituents are preferred.
Where R 1 and R 2 comprise an aryl or heteroaryl group and R 3 and R 4 comprise an alkyl group it is preferred that R 1 and R 2 are selected group 4-octylphenyl and 4-tert-butyl-phenyl substituents and that R 3 and R 4 comprises octyl substituents.
The polymers of the present invention may be homopolymers or copolymers. Suitable copolymers may comprise two, three or more distinct monomer-units. In a preferred embodiment the polymer of the present invention comprises a second repeat unit, preferably this repeat unit comprises a triarylamine or a heteroaromatic. Preferred triarylamine comonomers include N,N-di(4-phenyl)-N-(4-sec-butylphenyl)amine (“TA”) and bis[N-(4-phenyl)-N-(4-n-butylphenyl)]-phenylene-1,4-diamine (“BTA”).
The polymers of the present invention may be prepared by any suitable method. In a second aspect, the invention provides a monomer comprising an optionally substituted compound of formula (II):
wherein each P independently represents a polymerisable group and R 1 , R 2 , R 3 and R 4 are as defined above. Preferably each P is independently selected from a reactive boron derivative group selected from a boronic acid group, a boronic ester group and a borane group; a reactive halide group; or a moiety of formula —O—SO 2 —Z wherein Z is selected from the group consisting of alkyl and aryl, each being optionally substituted.
The polymers of the present invention are suitably prepared by aryl-aryl coupling such as Yamamoto coupling or Suzuki coupling, Suzuki coupling is preferred.
Accordingly, in a third aspect the invention provides a process for preparing a polymer comprising a step of reacting a first monomer as described in the second aspect of the invention and a second monomer that may be the same or different from the first monomer under conditions so as to polymerise the monomers.
This process preferably comprises polymerising in a reaction mixture:
(a) a monomer as described in the second aspect of the invention wherein each P is a boron derivative functional group selected from a boronic acid group, a boronic ester group and a borane group, and an aromatic monomer having at least two reactive functional groups independently selected from halides or a moiety of formula —O—SO 2 —Z; or (b) a monomer as described in the second aspect of the invention wherein each P is independently selected from the group consisting of reactive halide functional groups and moieties of formula —O—SO 2 —Z, and an aromatic monomer having at least two boron derivative functional groups selected from boronic acid groups, boronic ester groups and borane groups; or (c) a monomer as described in the second aspect of the invention wherein one P is a reactive halide functional group or a moiety of formula —OSO 2 —Z and one. P is a boron derivative functional group selected from a boronic acid group, a boronic ester group and a borane group,
wherein Z is selected from the group consisting of optionally substituted alkyl and aryl and the reaction mixture comprises a catalytic amount of a catalyst suitable for catalysing the polymerisation of the aromatic monomers, and a base in an amount sufficient to convert the boron derivative functional groups into boronate anionic groups without wishing to be bound to a specific theory.
In a fourth aspect, the invention provides an optical device comprising a polymer according to the first aspect of the invention. Preferably, the optical device is an organic light emitting device. In particular the polymers of the present invention may function as the electron transporting or light emissive components of an organic light emitting device.
In a fifth aspect, the invention provides a switching device comprising a polymer according to the first aspect of the invention.
Preferably, the switching device is a field effect transistor comprising an insulator having a first side and a second side; a gate electrode located on the first side of the insulator; an oligomer or polymer according to the first aspect of the invention located on the second side of the insulator; and a drain electrode and a source electrode located on the oligomer or polymer.
In a sixth aspect, the invention provides an integrated circuit comprising a field effect transistor according to the fifth aspect of the invention.
In a seventh aspect, the invention provides a photovoltaic cell comprising a polymer according to the first aspect of the invention.
In a eighth aspect, the invention provides a monomer comprising an optionally substituted repeat unit of formula (III):
wherein R 8 , R 9 , R 10 , R 11 , R 12 and R 13 are the same or different and independently represent hydrogen or a substituent as defined for R 1 -R 4 ; one or more of the pairs of R 8 and R 9 , R 10 and R 11 or R 12 and R 13 may be linked to form a monocyclic or polycyclic, aliphatic or aromatic ring system; and P is as described in the second aspect of the invention.
Preferably, R 8 , R 9 , R 10 and R 11 are independently selected from the group consisting of optionally substituted alkyl, alkyoxy, aryl, aryloxy, heteroaryl or heteroaryloxy.
Preferably, P is selected from the group consisting of reactive halide functional groups, a monovalent unit of formula —OSO 2 Z or a monovalent unit of formula —B(OR 14 )(OR 15 ) wherein R 14 and R 15 are the same or different and independently represent hydrogen or a substituent as defined for R 12 and R 13 and may be linked to form a ring; and Z is as described in the third aspect of the invention.
Preferably, R 12 , R 13 , R 14 and R 15 are the same or different and are selected from the group consisting of hydrogen and optionally substituted alkyl.
Preferably, R 12 and R 13 and/or R 14 and R 15 are linked to form an optionally substituted ethylene group.
In an ninth aspect the invention provides a process for preparing a polymer which comprises polymerising in a reaction mixture:
(a) a monomer according to the seventh aspect of the invention wherein P is a group of formula —B(OR 14 )(OR 15 ), and an aromatic monomer having at least two reactive functional groups independently selected from halide or moieties of formula —O—SO 2 —Z; or (b) a monomer according to the seventh aspect of the invention wherein P is a reactive halide functional group or a moiety of formula —O—SO 2 —Z,
wherein the reaction mixture comprises a catalytic amount of a catalyst suitable for catalysing the polymerisation of the aromatic monomers, and a base in an amount sufficient to convert the boron derivative functional groups into boronate anionic groups without wishing to be bound to a specific theory.
DETAILED DESCRIPTION OF THE INVENTION
Examples of repeat units according to the invention include the following:
Substitution of the aryl groups with one or more alkyl chains comprising 4 to 12 carbon atoms has been found to improve the solubility of the polymers and also to limit aggregation of the polymer chains.
The aryl groups may also be substituted with fluoro or fluoroalkyl groups. In particular long chain perfluoroalkyl substitutents are considered to reduce aggregation of the polymer chains. A further advantage of fluoro and fluoroalkyl substituted aryl groups is that the electron withdrawing properties of these groups increases the LUMO of the polymer and so enables more efficient electron injection into the polymer. Examples of fluorine substituted repeat units include:
The aryl groups may be substituted with other aryl groups such as phenyl and substituted phenyl groups, as shown by the repeat units below:
The repeat units may also be substituted with heteroaryl groups, in particular substituents based on pyridine, triazine and thiophene are considered to be useful:
The polymers of the present invention may also comprise repeat units where the substituents R 1 , R 2 , R 3 and R 4 are not identical. For example R 1 and R 2 may comprise aryl substituents and R 3 and R 4 alkyl substituents, as shown below:
Alternatively the repeat units may comprise three aryl substituents and a single alkyl substituent or vice-versa, examples of such repeat units include:
Repeat units comprising a pair of aryl substituents and a pair of alkyl substituted are preferred, particularly where the aryl substituents are further substituted with solubilising alkyl groups. This particular substitution pattern is considered to increase disorder in the polymer chains so decreasing the tendency of the polymer to aggregate. Examples include:
The aromatic groups in the main chain of the polymer may themselves be substituted, for example they may be fluorinated. It is preferred that any such substituent comprises fewer than four carbon atoms since larger substituents cause twisting along the polymer chain and so reduce conjugation along the polymer chain giving the polymer less desirable electronic properties.
Alternatively, two or more of R 1 , R 2 , R 3 and R 4 may be different aryls, which may be formed by methods disclosed in WO 00/22026 and DE 19846767. Examples of such repeat units include the following:
The groups R 1 and R 2 and/or R 3 and R 4 as described above may be linked to form a ring. Examples of such repeat units include the following:
The monomers which may be polymerised to form the repeat units of the polymers of the present invention may be prepared according to any suitable method. Preferred methods for the preparation of monomers of the invention such as tetraaryl trans-indenofluorenes, dialkyl diary trans-indenofluorenes, alkyl triaryl trans-indenofluorenes and trialkyl aryl trans-indenofluorenes are now described.
Scheme 1 illustrates a method for the preparation of a tetraaryl substituted monomer. Two equivalents of boronic ester 1a are coupled to dibromo aromatic compound 2a by Suzuki coupling using a palladium catalyst and a tetraethylammonium carbonate base. Compound 3a forms the starting material from which a wide variety of tetraaryl substituted trans-indenofluorenes may be prepared. Compound 3a is reacted with four equivalents of a metallated aromatic compound forming intermediate 4a which is heated in glacial acetic acid in the presence of HCl to form the tetraaryl substituted trans-indenofluorene 5a. In order to prepare monomers suitable to undergo Suzuki or Yamamoto coupling the compound 5a is brominated. The dibrominated compound 6a may be further reacted with a boronic ester to form a boronic diester 7a.
Scheme 2 below illustrates the preparation of a dialkyl diaryl substituted trans-indenofluorene.
The boronic ester of a suitably substituted fluorene is prepared, in Scheme 2 the fluorene 1b is a 9,9-dioctylfluorene. The boronic ester 1b undergoes Suzuki coupling with a 2-bromobenzoate 2b to form the terphenyl compound 3b. The terphenyl compound 3b is then reacted with two equivalents of a metallated aromatic compound to form intermediate 4b. Intermediate 4b is heated in glacial acetic acid to form the dialkyl diaryl trans-indenofluorene 5b. The dialkyl diaryl trans-indenofluorene may be further reacted to form the polymerisable compounds 6b and 7b.
Scheme 2 illustrates a method for the formation of a dialkyl diaryl trans-indenofluorene; in order to prepare, for example, alkyl triaryl trans-indenofluorenes or trialkyl aryl trans-indenofluorenes it is necessary that the starting compound 1b comprises a 9,9-unsymmetrically substituted fluorene. Suitable 9,9-unsymmetrically substituted fluorenes are disclosed in WO 00/22026 and DE 19846767. Scheme 3 below illustrates a method of forming monomers according to the invention wherein arylene substituents of the monomer are present in the starting material.
R in Scheme 3 represents a substituent. Where R is hydrogen, the above route may result in halogenation of the 4-position of the phenyl (or other aryl) substituent. Scheme 4 illustrates such a route.
The polymers of the present invention may be homopolymers or copolymers. The use of monomers with different electronic properties in copolymers allows a greater degree of control over the electronic and light emissive properties of the polymer.
A wide range of comonomers for polymerisation with the monomers of the invention will be apparent to the skilled person. One class of co-repeat units is arylene repeat units, in particular: 1,4-phenylene repeat units as disclosed in J. Appl. Phys. 1996, 79, 934; fluorene repeat units as disclosed in EP 0842208, trans-indenofluorene repeat units as disclosed in, for example, Macromolecules 2000, 33(6), 2016-2020; spirobifluorene repeat units as disclosed in, for example EP 0707020; and stilbene repeat units (commonly known as “OPV” repeat units) as disclosed in WO 03/020790. Each of these repeat units is optionally substituted. Examples of substituents include solubilising groups such as C 1-20 alkyl or alkoxy; electron withdrawing groups such as fluorine, nitro or cyano; and substituents for increasing glass transition temperature (Tg) of the polymer such as bulky groups, e.g. tert-butyl or optionally substituted aryl groups.
Further examples of comonomers include triarylamines as disclosed in, for example, WO 99/54385 and heteroaryl units as disclosed in, for example, WO 00/46321 and WO 00/55927.
Particularly preferred triarylamine repeat units for such copolymers include units of formulae 1-6:
X and Y may be the same or different and are substituent groups. A, B, C and D may be the same or different and are substituent groups. It is preferred that one or more of X, Y, A, B, C and D is independently selected from the group consisting of alkyl, aryl, perfluoroalkyl, thioalkyl, cyano, alkoxy, heteroaryl, alkylaryl and arylalkyl groups. One or more of X, Y, A, B, C and D also may be hydrogen. It is preferred that one or more of X, Y, A, B, C and D is independently an unsubstituted isobutyl group, an n-alkyl, an n-alkoxy or a trifluoromethyl group because they are suitable for helping to select the HOMO level and/or for improving solubility of the polymer.
Particularly preferred heteroaryl repeat units for such copolymers include units of formulae 7-21:
wherein R 6 and R 7 are the same or different and are each independently a substituent group. Preferably, one or both of R 6 and R 7 may be selected from hydrogen, alkyl, aryl, perfluoroalkyl, thioalkyl, cyano, alkoxy, heteroaryl, alkylaryl, or arylalkyl. These groups are preferred for the same reasons as discussed in relation to X, Y, A, B, C and D above. Preferably, for ease of manufacture, R 6 and R 7 are the same. More preferably, they are the same and are each hydrogen or a phenyl group.
The trans-indenofluorene repeat units of the present invention can act as efficient electron transporting units and light emitting units. It is therefore beneficial to combine the aryl substituted trans-indenofluorenes with hole transporting moieties such as triarylamines to provide polymers having electron and hole transporting and light emitting properties. A particularly useful example of such a polymer is the copolymer of a dialkyl diaryl trans-indenofluorene, TA and BTA shown below.
wherein w+x+y=1, w≧0.5, 0≦x+y≦0.5 and n≧2.
The polymers of the present invention are prepared by the polymerisation of monomers of formula (II):
where P is a polymerisable group. Preferably P is a boron derivative group such as a boronic ester or a reactive halide such as bromine.
Preferred methods for polymerisation of these monomers are Suzuki polymerisation as described in, for example, WO 00/53656 and Yamamoto polymerisation as described in, for example, T. Yamamoto, “Electrically Conducting And Thermally Stable pi-Conjugated Poly(arylene)s Prepared by Organometallic Processes”, Progress in Polymer Science 1993, 17, 1153-1205 or DE 10241814.4, or Stille coupling. For example, in the synthesis of a linear polymer by Yamamoto polymerisation, a monomer having two reactive halide groups P is used. Similarly, according to the method of Suzuki polymerisation, at least one reactive group P is a boron derivative group.
Suzuki polymerisation may be used to prepare regioregular, block and random copolymers. In particular, random copolymers may be prepared when one reactive group P is a halogen and the other reactive group P is a boron derivative group. Alternatively, block or regioregular, in particular AB, copolymers may be prepared when both reactive groups of a first monomer are boron and both reactive groups of a second monomer are halide. The synthesis of polymers with blocky structures is described in detail in, for example, DE 103 37 077.3. Suzuki polymerisation employs a Pd(0) complex or a Pd(II) salt. Preferred Pd(0) complexes are those bearing at least one phosphine ligand such as Pd(Ph 3 P) 4 . Another preferred phosphine ligand is tris(orthotolyl)phosphine, i.e. Pd(o-Tol) 4 . Preferred Pd(II) salts include palladium acetate, i.e. Pd(OAc) 2 . Suzuki polymerisation is performed in the presence of a base, for example sodium carbonate, potassium phosphate or an organic base such as tetraethylammonium carbonate.
Yamamoto polymerisation employs a Ni(0) complex, for example bis(1,5-cyclooctadienyl) nickel(0).
As alternatives to halogens as described above, leaving groups of formula —O—SO 2 Z can be used wherein Z is as described above. Particular examples of such leaving groups are tosylate, mesylate and triflate.
The aryl substituted poly(trans-indenofluorenes) of the present invention have particular application in optical devices, in particular organic light emitting devices. Organic light emitting devices comprise a layered structure comprising a lower electrode situated on a substrate for injection of charge carriers of a first type, an upper electrode for injection of charge carriers of a second type and a layer of organic light emitting material located between the lower and upper electrodes. Additionally, charge transporting layers of organic material may also be located between the electrodes. When a voltage is supplied across the electrode of the device opposite charge carriers, namely electrons and holes, are injected into the organic light emitting material. The electrons and holes recombine in the layer of organic light emitting material resulting in the emission of light. One of the electrodes, the anode, comprises a high work function material suitable for injecting holes into the layer of organic light emitting material, this material typically has a work function of greater than 4.3 eV and may be selected from the group comprising indium-tin oxide (ITO), tin oxide, aluminum or indium doped zinc oxide, magnesium-indium oxide, cadmium tin-oxide, gold, silver, nickel, palladium and platinum. The anode material is deposited by sputtering or vapour deposition as appropriate.
The other electrode, the cathode, comprises a low work function material suitable for injecting electrons into the layer of the organic light emitting material. The low work function material typically has a work function of less than 3.5 eV and may be selected from the group including Li, Na, K, Rb, Be, Mg, Ca, Sr, Ba, Yb, Sm and Al. The cathode may comprise an alloy of such metals or an alloy of such metals in combination with other metals, for example the alloys MgAg and LiAl. The cathode preferably comprises multiple layers, for example Ca/Al, Ba/Al or LiAl/Al. The device may further comprise a layer of dielectric material between the cathode and the emitting layer, such as is disclosed in WO 97/42666. In particular it is preferred to use an alkali or alkaline earth metal fluoride as a dielectric layer between the cathode and the emitting material. A particularly preferred cathode comprises LiF/Ca/Al, with a layer of LiF of thickness from 1 to 10 nm, a layer of Ca of thickness of 1 to 25 nm and a layer of Al of thickness 10 to 500 nm. Alternatively a cathode comprising BaF 2 /Ca/Al may be used. The cathode materials are deposited by vacuum deposition.
For light emission to occur from the device it is preferred that either the cathode, the anode or both are transparent or semi-transparent. Suitable materials for transparent anodes include ITO and thin layers of metals such as platinum. Suitable materials for transparent cathodes include a thin layer of electron injecting material in proximity to the layer of organic light emitting material and a thicker layer of transparent conductive material overlying the layer of electron injecting material e.g. a cathode structure comprising Ca/Au. Where neither the cathode nor the anode is transparent or semi-transparent light emission occurs through the edge of the device. It will be appreciated that such transparency is not a requirement where the polymers of the invention are used in switching devices.
The polymers of the present invention may comprise the light emissive layer of the device or may comprise an electron transport layer of the device. The polymers may be deposited by any suitable method although solution deposition methods are preferred. Solution deposition techniques include spin-coating, dip-coating, doctor blade coating, screen printing, flexographic printing and ink-jet printing. Ink-jet printing is particularly preferred as it allows high resolution displays to be prepared.
The organic light emitting device may include further organic layers between the anode and cathode to improve charge injection and device efficiency. In particular a layer of hole-transporting material may be situated over the anode. The hole-transport material serves to increase charge conduction through the device. The preferred hole-transport material used in the art is the conductive organic polymer polystyrene sulfonic acid doped poly(ethylene dioxythiophene) (PEDOT:PSS) as disclosed in WO 98/05187. Other hole transporting materials such as doped polyaniline or TPD (N,N′-diphenyl-N,N′-bis(3-methylphenyl)[1,1′-biphenyl]-4,4′-diamine) may also be used. A layer of electron transporting or hole blocking material may be positioned between the layer of light emitting material and the cathode if required to improve device efficiency.
The substrate of the organic light emitting device should provide mechanical stability to the device and act as a barrier to seal the device from the environment. Where it is desired that light enter or leave the device through the substrate, the substrate should be transparent or semi-transparent. Glass is widely used as a substrate due to its excellent barrier properties and transparency. Other suitable substrates include ceramics, as disclosed in WO 02/23579 and plastics such as acrylic resins, polycarbonate resins, polyester resins, polyethylene terephthalate resins and cyclic olefin resins. Plastic substrates may require a barrier coating to ensure that they remain impermeable. The substrate may comprise a composite material such as the glass and plastic composite disclosed in EP 0949850.
The organic light emitting device is provided with an encapsulation means which acts to seal the device from the atmosphere. Suitable methods of encapsulation include covering the device on the cathode side with a metal can or glass sheet or providing an impermeable film over the device, such as a film comprising a stack of polymer layers and inorganic layers.
The invention is further described by means of the following examples.
EXAMPLES
Monomer Synthesis
Synthesis of phenylboronic acid pinacol ester 1a
Phenyl boronic acid (100 g, 0.82 mol, 1 equiv.) and pinacol (96.92 g, 0.82 mol, 1 equiv.) were dissolved in toluene (500 mL) at room temperature. The cloudy solution was then placed on to a rotary evaporator and stirred for 2 hours at 60° C. After this period the solid had dissolved, concurrent with the formation of water (ca. 29.5 mL) as a second layer. The water was then removed in a separating funnel and the crude reaction filtered through Celite. Evaporation of the solvent yielded a clear pale yellow oil which solidified on cooling in a refrigerator to give the title compound in a near-quantitative yield as a white solid (ca. 167 g).
Synthesis of 2,5-diphenyl-terephthalic acid diethylester 3a
To a 3 L 3-neck flask equipped with a mechanical stirrer, reflux condenser and rubber septum was added phenyl boronic acid pinacol ester 2a (128.9 g, 0.63 mol, 2 equiv.) and 2,5-dibromo-terephthalic acid diethylester 1a (120 g, 0.32 mol, 1 equiv.) as a suspension in toluene (500 mL). A further 500 mL of toluene was then added and the reaction mixture briefly stirred before degassing using a nitrogen purge for 1 hour at 40° C. After this period dichloro-bis(triphenyl phosphine) palladium (II) (0.55 g, 0.78 mmol, 1/8 mol % per bromide) was added as a dry powder. The reaction mixture was then stirred under nitrogen for 15 minutes at 40° C. before the addition of tetra-ethylammonium carbonate (790 mL, ca. 33 wt % aqueous solution, 2 equiv. per arylboronate). The reaction was then stirred at 90° C. under nitrogen overnight (ca. 16 hrs.). TLC analysis at this point (DCM, silica plates) revealed a bright fluorescent blue spot (Rf ca. 0.6) and the absence of any starting material. Once the reaction mixture had cooled the aqueous layer was extracted and the solvent removed under reduced pressure to yield a light brown solid residue which was recrystallised from methanol to give the title compound as white crystalline solid. Slow evaporation of the mother liquor provided a second crop of product (92 g total, 77%, >99% pure by GC).
The radicals Aryl and Ar as used in formulae 4a, 5a, 6a, 7a, 4b, 5b, 6b, 7b, denote 4-(n-octyl)phenyl.
Synthesis of 2′,5′-bis(di(4-octylphenyl)hydroxymethyl)-1,1′,4′,1″-terphenyl 4a
Bromo-4-octyl-benzene (4 equivs.) was dissolved in anhydrous tetrahydrofuran
(THF) at −78° C. nBuLi (4 equivs., 2.5 M in hexanes) was then slowly added via a pressure equalised dropping funnel. After the addition the reaction was stirred for 30 minutes to insure complete transmetallation. 2,5-diphenyl-terephthalic acid diethylester 3a (1 equiv.) was then slowly added as a solution in THF. The temperature was maintained at −78° C. throughout the operation. After a further 30 minutes the reaction was allowed to warm up to room temperature and stirring was continued over night (ca. 16 hours). After this period water was added to destroy any unreacted butyl lithium and the THF removed under reduced pressure. The crude reaction mixture was extracted into dichloromethane (DCM) and purified by trituration from methanol.
Synthesis of 6,6,12,12-tetrakis-(4-octylphenyl)indeno[1,2-b]fluorene 5a
The arylated precursor 4a was heated in a mixture of glacial acetic acid and concentrated hydrochloric acid (a few drops) over night. After this period the reaction mixture was allowed to cool to room temperature before precipitation into a large excess of rapidly stirred water. The crude product was collected by filtration and purified by crystallisation.
Synthesis of 2,8-dibromo-6,6,12,12-tetrakis-(4-octylphenyl)indeno[1,2-b]fluorene 6a
Compound 5a was treated with an iodine/bromine mixture, as described in WO 00/55927.
Synthesis of 2,8-bis(boronic acid pinacol ester)-6,6,12,12-tetrakis-(4-octylphenyl)indeno[1,2-b]fluorene 7a
The title compound was prepared from compound 6a according to standard procedures as described in, for example, WO 00/55927.
Synthesis of 2-(2-methyl benzoate)-9,9-dioctylfluorene 3b
To a 3 L 3-neck flask equipped with a mechanical stirrer, reflux condenser and rubber septum was added 2-(boronic acid pinacol ester)-9,9-dioctylfluorene 1b (10 g, 21.72 mmol, 1 equiv.) and 2-bromo methyl benzoate 2b (4.67 g, 21.72 mmol, 1 equiv.) dissolved in toluene (100 mL) at room temperature. The solution was degassed using a nitrogen purge for 1 hour before dichloro bis(triphenyl phosphine) palladium(II) (20 mg, 0.027 mmol, 1/8 mol % per bromide) was added as a dry powder. The reaction mixture was then stirred under nitrogen for 15 minutes before the addition of tetra-ethylammonium carbonate (25 mL, ca. 33 wt % aqueous solution, 2 equiv. per arylboronate). The reaction was then stirred at 90° C. under nitrogen overnight (ca. 16 hrs.). TLC analysis at this point (DCM, silica plates) revealed a bright fluorescent blue spot (Rf ca. 0.6) and the absence of any starting material. Once the reaction mixture had cooled the aqueous layer was extracted and the solvent removed under reduced pressure to yield a yellow oil which was purified by recrystallisation to give the title compound.
Synthesis of 2-[phenyl-2-(diarylhydroxymethyl)]-9,9-dioctylfluorene 4b
Compound 4b was prepared in an analogous manner to compound 4a.
Synthesis of 6,6-dioctyl-12,12-bis(4-octylphenyl)indeno[1,2b]fluorene 5b
Compound 5b was prepared in an analogous manner to compound 5a.
Synthesis of 2,8-dibromo-6,6-dioctyl-12,12-bis(4-octylphenyl)indeno[1,2-b]fluorene 6b
Compound 6b was prepared in an analogous manner to compound 6a.
Synthesis of 2,8-bis(phenylboronic acid pinacol ester)-6,6-dioctyl-12,12-bis(4-octylphenyl)indeno[1,2-b]fluorene 7b
Compound 7b was prepared in an analogous manner to compound 7a.
Polymer Synthesis
Polymers according to the invention were prepared by Suzuki polymerisation of boronic acid diesters of aryl substituted indenofluorenes as described above with dibromo-arylamines according to the method described in WO 00/53656. For the purpose of comparison, identical polymers were prepared wherein substituents R 1 -R 4 of formula (I) above are all n-octyl.
Polymer 1 has a Tg of 240° C. In contrast, the corresponding polymer comprising tetra(n-octyl)indenofluorene has a Tg of 167° C. The higher Tg is beneficial for the use of the polymer in light emitting diodes and results in more stable blue emission.
Although the present invention has been described in terms of specific exemplary embodiments, it will be appreciated that various modifications, alterations and/or combinations of features disclosed herein will be apparent to those skilled in the art without departing from the spirit and scope of the invention as set forth in the following claims.
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The invention relates to organic semiconductive polymers comprising a new backbone system, monomers for the preparation of such polymers, methods for the preparation of such polymers and the use of such polymers in organic optoelectronic devices.
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BACKGROUND AND SUMMARY OF THE INVENTION
[0001] The Earth's natural resources are precious and provide for our survival. Among these resources are the fossil fuels we burn to power our great cities and to warm our homes. As a result of an enormous energy demand, we have created problems like excessive sulfur dioxide emissions, carbon dioxide emissions, catastrophic oil spills, power brown-outs, and nuclear waste. What, then, can we do to minimize these problems ? The most direct way is to implement energy conservation projects.
[0002] This patent disclosure details a unique, effective, and valuable invention to conserve energy lost through windows. Moreover, the energy that can be conserved is the energy necessary to maintain comfortable climates in homes and buildings. Not only can great amounts of energy be conserved with this invention, but auxiliary components such as mechanical furnace heaters and air conditioners will last longer with the substantial reduction in cyclical usage. Since the energy consumption in the United States alone exceeds 40 billion dollars annually for residential heating and cooling, there is a substantial economic gain to be made with this invention.
[0003] Specifically, an Energy Screen provides an optically clear means to insulate a window, thereby drastically reducing the heat transfer through the window. In the U.S., the architectural trend over the last 120 years has been to increase the window space in homes. Now, the energy lost through the windows approaches the energy lost through air changes in the entire house. This fact makes the energy screen the best invention to conserve energy in a house.
[0004] To derive maximum energy savings, this invention must be user friendly, easy to construct, optically clear, and pull out from the window easily. This invention is designed to be installed interiorly, so the user has easy access. The first requirement of this invention is a rigid frame that is easy to construct and must have ¼ inch clearance from the window recess. The frame must be rigid enough to have two layers of plastic film adhered to the frame and not bend or distort under small tension from the stretching or shrinking of the plastic. An easy to apply gasket will surround the perimeter of the frame. This gasket can be as simple as the 1 inch over coverage of the frame with the plastic films. Such a design will seal the energy screen within the window frame to create multiple dead air spaces, the condition required for good window insulation.
[0005] Theoretically, an Energy Screen will give the user additional insulation value comparable to a double pane window addition. Therefore, a 67% reduction in heat transfer is projected for single pane windows. If double pane windows are insulated with an Energy Screen, a 50% reduction in heat transfer is predicted. Given the great energy savings potential, its user friendly characteristics, and its optical clarity, this invention will be used in high demand.
DESCRIPTION OF THE PRIOR ART
[0006] In the past plastic films including vinyl, polyethylene, and heat shrink films have been tacked, taped, or affixed to a window frame. Customarily, these applications are disposable. If a good seal is obtained and no edge losses are assumed, a 1R insulation value is obtained. This new invention will get twice the insulation value of the old applications. Furthermore, reflective films and coatings may be applied to glass to reduce the summer cooling load. Unfortunately, these applications work against the wintertime heating load. Now this new invention will work year round for maximum energy savings.
[0007] A costly alternative product is the storm window. These glass windows are effective energy savers, but cost much more than an Energy Screen. Energy Screens are much easier to install. Also, low emissitivity glass has been used. This technology is priced too high for widespread acceptance. Currently, it is not feasible to retrofit existing windows.
[0008] U.S. Pat. No. 5,108,811 discloses a non optically clear window insulation. Most customers, however, prefer the optically clear Energy Screen.
ADVANTAGES
[0009] This invention will allow the user to fabricate their own custom fit window insulation. Kits can be sold for each window. The user can pull the interiorly fit Energy Screen out easily to open the window. Reinstallation is simple. A feature such as specifying the gasket as an 1 inch overlapping of the plastic film will further simplify the invention. Also, if the rigid frame is specified with sliding fit members, the user will not have to saw the rigid frame to make an exact fit for the window. Packaging and shipping the Energy Screen Kits will require smaller, more easy to handle, and less easy to damage, boxes.
DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a complete overview of an Energy Screen.
[0011] [0011]FIG. 2 is a hollow corner connection.
[0012] [0012]FIG. 3 is a wood corner connection drilled to fit a wood screw.
[0013] [0013]FIG. 4 is an aluminum H -clip used as a corner connection.
[0014] [0014]FIG. 5 is a solid corner connection.
[0015] [0015]FIG. 6 is an aluminum C-channel drilled to fit drilled holes in a melamine frame.
[0016] [0016]FIG. 7 is an adjustable rigid frame with slip fit members.
[0017] [0017]FIG. 8 is an overview of an Energy Screen where overlapping plastic films form a self-sealing gasket.
LISTING OF THE DRAWING REFERENCES
[0018] 1) Rigid frame.
[0019] 2) Plastic film.
[0020] 3) Foam gasket.
[0021] 4) Corner connection.
[0022] 5) Double sided adhesive tape.
[0023] 6) Pull-out knob.
[0024] 7) Solid rigid member.
[0025] 8) Hollow corner connection.
[0026] 9) Wood screw.
[0027] 10) Drilled screw starter hole.
[0028] 11) Wood rigid frame member.
[0029] 12) Aluminum H-clip.
[0030] 13) Rigid frame material.
[0031] 14) Hollow rigid frame member.
[0032] 15) Solid corner connection.
[0033] 16) Hollow rigid frame member.
[0034] 17) Wood screw.
[0035] 18) Aluminum C-channel.
[0036] 19) Melamine rigid frame member.
[0037] 20) Corner connection.
[0038] 21) Hollow tube rigid frame member.
[0039] 22) Solid tube rigid frame member that will insert into 21 snugly.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] The embodiments of this invention include the following elements:
[0041] 1) Rigid frame members.
[0042] 2) Corner connections.
[0043] 3) Double sided adhesive tape.
[0044] 4) Double plastic films.
[0045] 5) A gasket
[0046] 6) A pull-out knob.
[0047] Embodiment 1 consists of rigid members that can be connected to form a frame.
[0048] Materials suitable for a rigid frame include 7 ) metal, wood, plastic and melamine. These materials are solid. In contrast, 14 ) includes hollow rigid members made of aluminum, or extruded plastic. FIG. 7 shows how both solid and hollow rigid members can slide together to form an adjustable frame. Member 21 ), a hollow piece, slides into the corner piece and member 22 ), a solid piece, slides into member 21 ) on both ends. The advantage of a self sizing rigid frame means the user will not have to saw through a rigid member and smaller pieces make boxing and shipping easier.
[0049] The corner pieces, Embodiment 2, connect the rigid frame members together. A corner joint can be made as simple as drilling a starter hole through wood ½×¾ inch and threading a wood screw through it. See FIG. 3.
[0050] Injection molded corner pieces can be manufactured hollow 8 ) to accept solid rigid members or manufactured solid 15 ) to accept hollow rigid members. Currently, Elgar Products Inc. of Cleveland, Ohio sells a line of bug screening materials including solid corner pieces which slip fit into hollow aluminum framing material. These materials are acceptable for making interior fitting Energy Screens. However, to make a self adjustable frame, a solid steel, aluminum, or plastic members will be required to slip fit into Elgar's hollow aluminum framing material. See FIG. 7.
[0051] Other corner possibilities include aluminum H-clips 12 ) which when used in conjunction with an epoxy composition will make a tight fit with melamine 13 ). See FIG. 4.
[0052] Another corner possibility includes a 4 inch long by ½ inch aluminum C-channel 18 ) piece with two drilled holes. This piece will hold the conjunction of two ½ inch thick by 2 inch wide melamine rigid members 19 ). Two starter holes will have to be made to accept two wood screws 17 ). See FIG. 6.
[0053] Not shown in the drawings are various right angle braces and hardware that can be used to join wood and melamine.
[0054] Embodiment 3 specifies a double sided adhesive tape that will adhere the plastic films to both sides of the frame 5 ). Once the frame has been sized to fit the particular window, the tape can be applied in four pieces around both sides of the frame.
[0055] Embodiment 4 requires two plastic films. The best material is a heat shrinkable film that can be hand fitted onto the frame 2 ). Most all the wrinkles in the plastic films can be smoothed out by careful placement. If necessary, the heat from a hot hair dryer will eliminate remaining wrinkles.
[0056] Embodiment 5 is the gasket 3 ). See FIGS. 1 and 8. The gasket can be made from closed cell foam material or by enclosing open cell foams with ½ mil polyethylene. Polyethlene, polyurethane, or sponge rubber can form a suitable gasket material. Preferably, a 1 inch overlapping of the plastic films with the frame will make a good seal and can act as the gasket. See FIG. 8. This will substantially reduce the cost and complexity of an Energy Screen. The user can feel by hand around the gasket to insure good sealing on a cold day.
[0057] Finally, a pull-out knob 6 ) can be affixed to the bottom member of the rigid frame. A hole can be drilled and a cabinet hardware knob screwed into place for easy removal of the Energy Screen. Alternatively, for convenience, two knobs can be screw fitted on the bottom corner pieces of the invention.
CONCLUSIONS
[0058] In his book, Movable Insulation, Langdon reports a 42% savings in the overall heating load for 2R of added window insulation. Clearly, significant energy savings are anticipated for Energy Screens. Although Langdon's experimental models were non optically clear, this means insulation must be removed during daylight hours to realize solar energy gains. The present invention is a vast improvement. Now, movable insulation technology is passive. Even more energy savings can be expected.
[0059] In summation, an easy to assemble Energy Screen Kit can conserve vast amounts of energy. Now, optically clear films will make the applied kit unnoticeable to users. Little or no reluctance to install these kits should be expected. With the national energy consumption exceeding 40 billion dollars each year to cool and heat residences, this invention should sell well. The great energy savings realized with this invention will conserve fossil fuels and minimize problems associated with their aggressive use. The inventor will benefit, the user will save on utility bills, the utilities will produce less pollution, and everyone in the world will benefit from a cleaner environment.
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Analogous to a bug screen for windows, an Energy Screen is a rigid frame covered with two clear films of plastic which is applied fittingly to the interior of a window. This will conserve the heating and cooling load of a house by as much as 42%. An easy to assemble kit is disclosed which does not require sawing rigid members, but installs with scissors as the only tool.
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CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
The invention relates to compositions, methods, and apparatuses for improving paper surface strength. Paper is sheet material containing interconnected small, discrete fibers. The fibers are usually formed into a sheet on a fine screen from a dilute water suspension or slurry. Paper typically is made from cellulose fibers, although occasionally synthetic fibers are used.
As described in U.S. Pat. No. 5,585,456, paper products made from untreated cellulose fibers lose their strength rapidly when they become wet, i.e., they have very little wet strength. The wet strength of paper is defined as the resistance of the paper to rupture or disintegration when it is wetted with water. Wet strength of ordinary paper is only about 5% of its dry strength. To overcome this disadvantage, various methods of treating paper products have been employed.
One method of increasing the strength of paper is by the addition of a starch coating to the surface of paper. As described in U.S. Pat. No. 4,966,652, although originally applied to size (make resistant to water penetration) paper, starch coatings also increase the stiffness of paper. The increase in stiffness is so pronounced that it makes paper suitable for use in such applications as container board, packaging papers, and sheet fed printer papers. The starch is commonly added onto the paper sheet by an Can-machine process (such as a size press device) or an off-machine process.
As described for example in U.S. patent application Ser. No. 12/323,976, the high cost of paper fiber makes the strength enhancing process even more crucial. Increasingly paper manufacturers are adding significant amounts of less expensive filler materials to defray costs and to enhance other properties required in the paper such as whiteness and brightness. However, papermakers are limited in the amount of fillers in the final product due in great part to a net loss in strength. Tensile strength, z-directional tensile strength and the tendency of the paper to shed filler particles (dusting) during typical handling processes, e.g., printing, are some of the main properties affected. U.S. Pat. No. 7,488,403 describes a method of enhancing the strengthening effect by adding a glyoxylated polyacrylamide polymer to the paper sheet. However there remains a continuing need in the art for methods of imparting appropriate levels of wet strength to paper products.
The art described in this section is not intended to constitute an admission that any patent, publication or other information referred to herein is “prior art” with respect to this invention, unless specifically designated as such. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 CFR §1.56(a) exists.
BRIEF SUMMARY OF THE INVENTION
At least one embodiment of the invention is directed towards a method of coating a paper substrate. The method comprises the steps forming a composition by contacting starch and a synthetic polymer during a starch cooking process in a fluid under temperature and conditions sufficient to gelatinize the starch, and applying the composition to a paper substrate, the synthetic polymer not being a starch. The contact may occur after and/or before the starch cooking process has begun. The synthetic polymer may be a copolymer formed from monomer units of both acrylic acid and acrylamide. The starch may be a solid before it is cooked. The composition may have a viscosity greater than a composition in which the polymer only enters the composition after the starch has been cooked. The paper substrate may comprises filler particles and may have a greater surface strength than a paper product similarly made but in which a smaller amount of filler was present and the polymer was added to the composition after cooking. The composition may be applied to a paper substrate by one device selected from the list consisting of a size press device, print roll coater device, air-knife coater device, metering bar coater device, blade coater device, under vacuum coater device, cast coating device, and any combination thereof. A paper product made from the paper substrate may have a greater strength than a paper product made from the same materials but with a smaller amount of starch and in which the polymer was added to the composition after cooking.
Additional features and advantages are described herein, and will be apparent from, the following Detailed Description.
BRIEF DESCRIPTION OF THE DRAWINGS
A detailed description of the invention is hereafter described with specific reference being made to the drawings in which:
FIG. 1 is a graph illustrating how the invention improves the strength of a paper sheet.
FIG. 2 is a graph illustrating how the invention increases the viscosity of a starch solution.
For the purposes of this disclosure, like reference numerals in the figures shall refer to like features unless otherwise indicated. The drawings are only an exemplification of the principles of the invention and are not intended to limit the invention to the particular embodiments illustrated.
DETAILED DESCRIPTION OF THE INVENTION
The following definitions are provided to determine how terms used in this application, and in particular how the claims, are to be construed. The organization of the definitions is for convenience only and is not intended to limit any of the definitions to any particular category.
“Consisting Essentially of” means that the methods and compositions may include additional steps, components, ingredients or the like, but only if the additional steps, components and/or ingredients do not materially alter the basic and novel characteristics of the claimed methods and compositions.
“Cooking” means applying thermal energy to a fluid giving it sufficient energy to accelerate the process of gelatinizing starch.
“Free,” “No,” “Substantially no” or “Substantially free” means a composition, mixture, or ingredient that does not contain a particular compound or to which a particular compound or a particular compound-containing compound has not been added.
“GCC” means ground calcium carbonate filler particles, which are manufactured by grinding naturally occurring calcium carbonate rock
“Papermaking Process” means a method of making paper products from a pulp comprising forming an aqueous fibrous papermaking furnish from processed pulp typically comprising cellulose fibers, draining the furnish to form a wet sheet and drying the sheet to form a dry sheet. The steps of forming the papermaking furnish, draining, and drying may be carried out in any conventional manner generally known to those skilled in the art.
“Paper Substrate” means furnish, wet sheet, and/or dry sheet from a papermaking process.
“PCC” means precipitated calcium carbonate filler particles, which are synthetically produced.
“Pre-cooked Starch” means starch which is in such an insoluble form that when within water in the absence of cooking heat or other chemical agents, it is largely insoluble and can only be dispersed into a suspension.
“Polysaccharide” means a polymeric carbohydrate having a plurality of repeating units comprised of simple sugars, the C—O—C linkage formed between two such joined simple sugar units in a polysaccharide chain is called a glycosidic linkage, and continued condensation of monosaccharide units will result in polysaccharides, common polysaccharides are amylose and cellulose, both made up of glucose monomers, polysaccharides can have a straight chain or branched polymer backbone including one or more sugar monomers, common sugar monomers in polysaccharides include glucose, galactose, arabinose, mannose, fructose, rahmnose, and xylose.
“STP” means standard temperature and pressure.
“Surfactant” is a broad term which includes anionic, nonionic, cationic, and zwitterionic surfactants. Enabling descriptions of surfactants are stated in Kirk - Othmer, Encyclopedia of Chemical Technology , Third Edition, volume 8, pages 900-912, and in McCutcheon's Emulsifiers and Detergents , both of which are incorporated herein by reference,
“Surface Strength” means resistance to loss of material due to abrasive forces applied along the surface of a substrate, one means of measuring surface strength is described in the test protocol in TAPPI 476.
“Suspension” means a thermodynamically unstable generally homogenous fluid containing an internal phase material dispersed throughout an external phase material, because the internal phase material does not dissolve in the external phase material, over time in the absence of some input of energy (such as mechanical agitation, excipients, or chemical suspending agents) the internal phase material will settle out, the external phase material may be a solid and often has a volume larger than 1 micrometer 3 .
In the event that the above definitions or a description stated elsewhere in this application is inconsistent with a meaning (explicit or implicit) which is commonly used, in a dictionary, or stated in a source incorporated by reference into this application, the application and the claim terms in particular are understood to be construed according to the definition or description in this application, and not according to the common definition, dictionary definition, or the definition that was incorporated by reference. In light of the above, in the event that a term can only be understood if it is construed by a dictionary, if the term is defined by the Kirk-Othmer Encyclopedia of Chemical Technology, 5th Edition, (2005), (Published by Wiley, John & Sons, Inc.) this definition shall control how the term is to be defined in the claims.
At least one embodiment of the invention is directed towards a method of increasing the surface strengthening effect that a starch containing coating can impart to a sheet of paper. The method includes the steps of preparing a strengthening composition by cooking starch in the presence of a synthetic polymer in a fluid (such as water), allowing the synthetic polymer and starch to complex with each other in the presence of heat sufficient to increase the gelatinization of the starch in the fluid, and applying the composition to a sheet of paper.
In at least one embodiment the synthetic polymer contacts the starch before the starch has begun to be cooked. In at least one embodiment the synthetic polymer contacts the starch after the starch has begun to undergo a cooking process.
In at least one embodiment the pre-cooked starch and the synthetic polymer are kept in a non-cooking state for between 1 minute and 57 years prior to cooking.
In at least one embodiment the temperature of the non-cooking state is no greater than 30° C.
In at least one embodiment the temperature of the cooking process is between STP and 200° C.
In at least one embodiment the fluid the starch is cooked in is at least in part a liquid. In at least one embodiment the fluid the starch is cooked in is at least in part a gas. In at least one embodiment the fluid the starch is cooked in is at least in part water. In at least one embodiment the fluid the starch is cooked in is at least in part steam.
As described in the textbook Handbook for Pulp & Paper Technologists (7th Printing), by G. A. Smook, TAPPI (1982), (hereinafter “Smook”) (generally and in particular in chapter 18), starch is stored and transported in a pre-cooked format. When pre-cooked, the starch is typically a white granular powder. This powder is largely insoluble in cold water because of its polymeric structure and because of hydrogen bonding between adjacent polymer chains. In order for it to be effective as a paper coating however, water needs to penetrate into the structure and thereby gelatinize the starch into a form suitable for coating. In the absence of an energy input (such as vigorous stirring over a long period of time or added heat) the hydrogen bonding resists and impairs water penetration and gelatinization occurs either extremely slowly or not at all. When an aqueous suspension of pre-cooked starch is heated or cooked, the water is able to penetrate into the structures and swell up and gelatinize the starch. Heating and cooling of the now cooked starch can be performed to obtain a desired viscosity appropriate for applying the starch with a coating device. Typically a starch composition is applied by a coating device when it has a low viscosity achieved by the composition being between 6-15% starch and 85-94% water.
In at least one embodiment the cooking process excludes applying a temperature or pressure so extreme as to chemically degrade either of the starch and/or the synthetic polymer.
As elegantly illustrated in Smook's FIGS. 18-5 and 18-6 (page 266), according to the prior art, starch is first cooked and only afterwards is combined with other chemical additives such as strengthening agents to form a composition applied by a coating process. It has however been discovered that by allowing starch to remain in contact with a synthetic polymer during the cooking process, the properties of the resulting cooked starch change. Among those changed properties are greater strengthening effect and a greater viscosity than if the starch and the polymer had come into contact with each other after the cooking process. In addition, because of the intense temperature and pressure effects of the cooking process and because of the specific conditions required to form synthetic polymers, it was not anticipated that synthetic polymers could survive the intense cooking process in a form which preserved their beneficial properties.
Without being limited by a particular theory or design of the invention or of the scope afforded in construing the claims, it is believed that when the starch and the synthetic polymer contact each other while being cooked together, they form a complex that does not otherwise form and that enhances the properties of the starch. This complex is believed to rely upon interactions too weak to form covalent bonds, but which holds the synthetic polymer and starch together by hydrogen bonds. In addition the altered geometry may change the configuration with which water can gelatinize the starch affecting its viscosity. As a result a starch cooked while in contact with a synthetic polymer is chemically different from cooked starch which has had a synthetic polymer added to it after the starch has been cooked. Objective evidence of these differences can be seen by the differences in viscosity shown in FIG. 2 . These differences are believed to distribute the synthetic polymer relative to the paper sheet in a more beneficial manner.
In at least one embodiment the starch comprises: natural starch, modified starch, amylose, amylopectin, styrene-starch, butadiene starch, starches containing various amounts of amylose and amylopectin, such as 25% amylose and 75% amylopectin (corn starch) and 20% amylose and 80% amylopectin (potato starch); enzymatically treated starches; hydrolyzed starches; heated starches, also known in the art as “pasted starches”; cationic starches, such as those resulting from the reaction of a starch with a tertiary amine to form a quaternary ammonium salt; anionic starches; ampholytic starches (containing both cationic and anionic functionalities); cellulose and cellulose derived compounds; and any combination thereof and/or a combination thereof which explicitly excludes one or more of these. Some representative examples of starch can be found in U.S. Pat. Nos. 5,800,870, and 5,003,022.
In at least one embodiment the composition of the starch is such that but for the contact between the starch and the synthetic polymer during the cooking process, the composition would not have proper viscosity and/or proper strengthening properties.
In at least one embodiment the synthetic polymer is a copolymer, terpolymer, etc. . . . the polymer includes monomeric units of acrylic acid and acrylamide. Additional monomeric units that may be present in the synthetic polymer include one or more of cationic character conferring monomers and other vinyl monomers.
In at least one embodiment the synthetic polymer and/or the starch is linear, branched, cyclic, and/or hyperbranched.
In at least one embodiment the synthetic polymer excludes starch.
Representative cationic character conferring monomers include: diallyl quaternary monomer (generally diallyl dimethyl ammonium chloride, DADMAC), 2-vinylpyridine, 4-vinylpryridine, 2-methyl-5-vinyl pyridine, 2-vinyl-N-methylpyridinium chloride, p-vinylphenyl-trimethyl ammonium chloride, 2-(dimethylamino)ethyl methacrylate, trimethyl(p-vinylbenzyl)ammonium chloride, p-dimethylaminoethylstyrene, dimethylaminopropyl acrylamide, 2-methylacroyloxyethyltrimethyl ammonium methylsulfate, 3-acrylamido-3-methylbutyl trimethyl ammonium chloride, 2-(dimethylamino)ethyl acrylate, and mixtures thereof. In addition to chloride, the counterion for the cationic monomers also can be fluoride, bromide, iodide, sulfate, methylsulfate, phosphate, and the like, and any combination thereof.
Other vinyl monomers that can be present during preparation of the synthetic polymer include: acrylic esters such as ethyl acrylate, methylmethacrylate and the like, acrylonitrile, vinyl acetate, N-vinyl pyrrolidone, N,N′-dimethyl acrylamide, hydroxy alkyl(meth)acrylates, styrene and the like, allylglycidal ether, glycidyl methacrylate, co-monomers with a 1,2-diol in their structure, such as 3-allyloxy-1,2-propandiol, 3-acryloyloxy-1,2-propandiol and methacryloyloxy-1,2-propandiol, and the like, and any combination thereof.
In at least one embodiment glyoxal is also present when the starch and the synthetic polymer are cooked together. In at least one embodiment a glyoxyated polyacrylamide polymer is present when the pre-cooked starch and the synthetic polymer are contacted. In at least one embodiment the synthetic polymer or the material that is contacted with the cooking starch is one or more of those compositions described in one or more of U.S. Pat. Nos. 4,966,652, 5,320,711, 5,849,154, 6,013,359, 7,119,148, 7,488,403, 7,589,153, 7,863,395, 7,897,103, 8,025,924, 8,101,046, 8,163,134, and 8,273,215.
In at least one embodiment the strengthening composition is applied to a paper substrate by one or more of: a size press device, print roll coater device, air-knife coater device, metering bar coater device, blade coater device, under vacuum coater device, cast coating device, and any combination thereof. A representative size press device is described in U.S. Pat. No. 4,325,784. In at least one embodiment the application is performed by an on-machine operation or an off-machine operation. Other examples of coating devices, compositions added to the strengthening composition (after starch cooking), and synthetic polymers (which are present during and/or after starch cooking) are described in US Patent Application 2005/0155731.
In at least one embodiment the composition is applied to a filler-bearing paper substrate. The filler particles may be PCC, GCC, and any combination thereof.
In at least one embodiment the resulting paper has superior strength alongside more filler and/or superior optical properties despite having filler or optical property enhancing material in an amount that but for the cooking contact would have produced lessor strength. Optical properties include but are not limited to whiteness, brightness, and opacity all of which are defined as described in the reference Measurement and Control of the Optical Properties of Paper, 2 nd ed., Technidyne Corporation, New Albany, Ind., (1996).
EXAMPLES
The foregoing may be better understood by reference to the following examples, which are presented for purposes of illustration and are not intended to limit the scope of the invention.
Several laboratory experiments have been conducted to measure the ability of an AA/AcAm copolymer to increase the surface strength of paper. Except in study 3, base paper containing 16% ash and that has not been passed through a size press was coated using the drawdown method with solutions containing the desired chemistry. The paper was weighted before and after coating to determine specific chemical dose. The paper was dried by passing it once through a drum dryer at about 95° C. and allowed to equilibrate at 23° C. and 50% relative humidity for at least 12 hours.
Surface strength was measured using TAPPI (Technical Association of Pulp and Paper Industries) method T476 om-01. In this measurement, the surface strength is inversely proportional to the amount of mass lost from the surface of the paper after having been systematically “rubbed” on a turn table by two abrasion wheels. The results are reported in mg of lost material per 1000 revolutions (mg/1000 revs): the lower the number the stronger the surface.
Below is a summary of the studies conducted in the laboratory.
Study 1. Screening.
This first study was designed to determine which polymer performed the best among a set of samples varying in acrylic acid mole ratio and/or average molecular weight. Table 1 shows the conditions and the results.
TABLE 1
Acrylic
Abrasion
acid/
loss,
Polymer,
acrylamide
Average
mg/1000
Condition
Starch, lb/t
lb/t
ratio
MW
revs
1
14.8
0.00
—
—
1104.4
2
27.0
0.00
—
—
779.4
3
21.2
0.92
7.5/92.5
Low
856.7
4
20.5
0.89
7.5/92.5
High
804.4
5
19.6
0.85
15/85
—
765.6
6
19.1
0.83
30/70
—
798.3
The first two conditions span a range of starch dose within which the conditions containing the polymers will be dosed. The abrasion loss results demonstrate that the strongest surface is obtained with the copolymer containing 15% acrylic acid. The results of the two polymers containing 7.5% acrylic acid suggest that the higher average molecular weight polymer performs better.
Study 2. Monomer Ratio.
This study was designed to determine which polymer performed the best among a set of samples varying only in acrylic acid mole ratio. Table 2 shows the conditions and the results.
TABLE 2
Abrasion
Acrylic
Polyacrylic
loss,
acid/acrylamide
Starch,
acid/acrylamide,
mg/1000
Condition
ratio
lb/t
lb/t
revs
1
—
15.0
0.00
441.7
2
—
25.9
0.00
262.5
3
7.5/92.5
19.2
0.83
321.7
4
15/85
19.8
0.86
207.5
5
30/70
18.9
0.82
285.8
The first two conditions are meant to span a range of starch dose within which the conditions containing the polymers will be dosed. The abrasion loss results demonstrate that the strongest surface is obtained with the copolymer containing 15% acrylic acid.
Study 3. Ash Replacement.
This study was designed to compare surface strength performance as a function of ash content. Controlling only for ash content, base sheets were prepare in the lab using a Noble and Wood mold, pressed in a static lab press and dried in a drum dryer at approximately 100° C. All wet end chemistries were maintained constant. Table 3 shows the conditions and the results.
TABLE 3
Abrasion
Acrylic acid,
Acrylic acid/
loss,
%-Average
Starch,
acrylamide,
mg/
Condition
MW, kDa
lb/t
lb actives /t
Ash, %
1000 revs
1
—
63.7
0.00
15.9
346
2
—
66.2
0.00
23.9
483
3
7.5-200
61.8
1.03
15.5
303
4
7.5-200
66.2
1.10
23.8
449
5
15-400
62.6
1.04
15.5
262
6
15-400
58.9
0.98
23.2
346
The first two conditions only contained starch, while the others contained about 1 lb/t of an AA/AcAm copolymer. The increase in surface strength is maximized with the higher average molecular weight copolymer containing 15% acrylic acid,
Study 4. Cooking a Blend of Starch and AA/AcAm.
Table 4 illustrates a study designed to test the effect of cooking the starch in the presence of the AA/AcAm copolymer.
TABLE 4
Starch and
Abrasion
polymer cooked
Starch,
AA/AcAm,
loss,
Condition
together?
lb/t
lb/t
mg/1000 revs
1
No
21.3
0.00
1156
2
No
31.2
0.00
1034
3
No
37.2
0.00
880
4
No
16.4
1.09
1064
5
No
24.4
1.06
924
6
No
31.8
1.06
794
7
Yes
15.9
1.06
944
8
Yes
22.5
0.98
759
9
Yes
30.1
1.00
588
The results of these tests demonstrate that the formulation where the starch was cooked in the presence of a synthetic polymer such as AA/AcAm copolymer performs better than the formulation where the blending was done after cooking the starch.
While this invention may be embodied in many different forms, there are described in detail herein specific preferred embodiments of the invention. The present disclosure is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated. All patents, patent applications, scientific papers, and any other referenced materials mentioned herein are incorporated by reference in their entirety. Furthermore, the invention encompasses any possible combination of some or all of the various embodiments described herein and/or incorporated herein. In addition the invention encompasses any possible combination that also specifically excludes any one or some of the various embodiments described herein and/or incorporated herein.
The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims.
All ranges and parameters disclosed herein are understood to encompass any and all subranges subsumed therein, and every number between the endpoints. For example, a stated range of “1 to 10” should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more, (e.g. 1 to 6,1), and ending with a maximum value of 10 or less, (e.g. 2.3 to 9.4, 3 to 8, 4 to 7), and finally to each number 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 contained within the range. All percentages, ratios and proportions herein are by weight unless otherwise specified.
This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.
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The invention provides methods and compositions for increasing the strengthening effect of a starch coating on paper. The method involves contacting the starch with a synthetic polymer before the starch is cooked. This changes how the starch gelatinizes and how the polymer gets distributed on the paper resulting in greater paper surface strength.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to European Application 12178536.4 filed Jul. 30, 2012, the contents of which are hereby incorporated in its entirety.
TECHNICAL FIELD
The present invention relates to the field of stationary gas turbine arrangement with at least one turbine stage comprising at least a first row of vanes being mounted at a stationary component arranged radially outwards of the first row of vanes and extending radially into an annular entrance opening of the turbine stage facing a downstream end of a combustor.
BACKGROUND OF THE INVENTION
A typical stationary gas turbine arrangement provides a burner with a combustor in which hot gases are produced which flow into a turbine stage in which the hot gases performing expansion work. The turbine stage consists of a rotary shaft on which a multitude of blades are arranged and grouped in axially blade rows. The rotary unit is encapsulated by a stationary casing on which vanes are mounted which are also divided in axial distributed vane rows each extending between the blade rows. For performing maintenance work on a typical stationary gas turbine, it is necessary to lift the uppercasing half of the turbine stage to get access to the rotary unit. In most of the cases, it is unavoidable to remove also the rotary unit from the lower casing half for further disassembling work. It is a matter of fact that maintenance work on conventional stationary gas turbines is time and cost consuming which is a significant disadvantage for the gas turbine operating company.
Basically it is known that for inspection work inside the outer casing of a turbine stage so called manholes are integrated, so that worker person can gain access to the inner core of the stationary components of the first turbine stage. However, it is not possible to get a direct access to the vanes or blades extending inside the turbine stage because the stationary components, which carry the blades divided in several axially blade rows are typically manufactured in one piece having an axial extension of the length of the turbine stage. In FIG. 2 , a rough sketch illustrates a longitudinal section view through the first stage gas turbine in the region of the first vane 1 and blade 2 . Hot gases 3 , which are produced inside a combustor 4 flow through the funnel shaped entrance opening 5 of a first turbine stage 6 . Hot gases 3 pass in axial direction through circumferential interspaces between the blades 1 , which are arranged circumferentially around the rotor axis 7 of the rotor unit 8 . Each vane 1 provides a radial outer platform 9 , an airfoil 1 ′ and a radial inner platform 10 . The radial outer platform 9 contains mounting hooks 11 , which are inserted into mounting groves 12 of the stationary component 13 of the first turbine stage. The inner platform 10 of vane 1 typically encloses a gap 14 with the inner combustor liner 15 through which a purge flow of cooling medium 16 can be injected into the hot gas flow 3 . In the same way a purge flow of cooling medium 16 ′ is injected through a gap 14 ′ that is enclosed by parts of the stationary component 13 , the upstream edge of the platform 9 of vane 1 and the outer combustor liner 15 ′. Downstream the outer platform 9 a heat shield 9 ′ is mounted inside of the stationary component 13 which prevents overheating of the inner faced areas of the stationary component in the same way as in case of the outer platform 9 .
EP 2 447 475 A2 discloses an airfoil attachment arrangement in which the airfoil 46 is mounted between an outer and inner platform 48 , 50 . For mounting and demounting purposes in the outer platform 50 , an aperture 90 is processed through which the airfoil can be moved radially. Also at the inner platform 48 , (see FIG. 11 ) there is an opening (see FIGS. 11 to 13 ) through which the radial inner end of the airfoil 46 penetrates partially. Both ends of the airfoil 46 are fixed by retention assemblies. FIGS. 4 and 5 show a retention assembly 54 for fixing the radial outward end of the airfoil 46 . FIG. 12 shows a retention assembly 126 for fixing the radially inner end of the airfoil 46 .
U.S. Pat. No. 6,189,211 B1 discloses a method and arrangement for carrying out repair and/or maintenance work in the inner casing of a multi-shell turbo machine. For getting access to the vanes of the first row a man hole 21 is provided within the outer casing of the gas turbine plant. For getting access to the row of vanes, the top part of the combustion chamber casing 12 can be lifted off by a lifting device 33 as disclosed in FIG. 2 .
U.S. Pat. No. 3,004,750 A discloses a stator for compressor or turbine arrangement which shows especially turbine arrangement which shows especially in FIGS. 1 to 4 that in a stationary component which is the shroud 2 several through-holes 8 are provided through each of which a vane 6 can be inserted. Each vane 6 provides at its radially outer end a so called foot 10 overlying the outer surface of the outer shroud 2 , so that when the vane 6 is inserted into the slot 8 , the slot is sealed air tightly especially by welding 12 the foot 10 against the outer surface of the shroud 2 . The radially inner end of the vane 6 extends into a slot 26 in the inner shroud 4 . Inside the slot 26 , there is a spring pin 32 , which provides a damping effect on the vane 6 .
A similar construction of mounting of vanes 34 within a gas turbine engine is disclosed in U.S. Pat. No. 4,643,636 A, which shows an assembly including a ceramic inner and outer shroud rings in which recesses are provided through which vanes can radially mounted therein. For securing of the vanes a ceramic outer support ring 40 slides over the outer shroud ring
FR 2 671 140 A1 discloses guide vanes for a turbo machine compressor (see FIG. 1 ). Inside the outer shroud segment 2 , through-holes 7 are provided through which vanes 3 can be inserted radially. The radially inner end of the vane is received by a slot of an inner ring segment 4 . The vane 3 can be secured by a fixing plate 9 , which is pressed inside a recess 10 at a mounting device 8 fixed on the outer shroud 2 .
SUMMARY
It is an object of the invention to provide a stationary gas turbine arrangement with at least one turbine stage comprising at least a first row of vanes being mounted at a stationary component arranged radially outside of the first row of vanes and extending radially into an annular entrance opening of the turbine stage facing a downstream end of a combustor, which shall enable to reduce significantly the dissembling and assembling work for performing maintenance work on the stationary gas turbine. Especially the lift off process of the uppercasing half of the turbine stage casing shall be avoided.
The object is achieved by the sum total of the features of claim 1 . Claim 6 is directed to a method for performing maintenance work on a stationary gas turbine. The invention can be modified advantageously by the features disclosed in the sub claims as well in the following description especially referring to preferred embodiments.
The inventive idea leaves the use of typical vanes consisting of an airfoil, an inner, and an outer platform made in one piece as depicted and explained in connection with FIG. 2 . Especially by using a vane, which can be assembled by at least two separate parts, i.e. a separate airfoil and outer platform and a separate inner platform, preconditions are created to provide a direct access to the inner region of a first turbine stage without removing the uppercasing half of the turbine stage. It is also possible to use vanes of three separable parts, i.e. outer platform, airfoil, and inner platform. The inventive stationary gas turbine arrangement provides a radially orientated through-hole within the stationary component for each vane designed and arranged such that a radial insertion and removal of the airfoil of the vane is possible. Typically, the cross section of such a through-hole is in the shape of the largest airfoil profile so that the airfoil of the vane can be moved through the through-hole in its entire airfoil length.
In a preferred first embodiment, the airfoil of each vane has at its end directed radially inwards an extension for inserting into a recess of an inner platform for the purpose of a detachable fixation. As it will be described later, the inner platform is connected with an inner structure respectively inner component of the turbine stage.
The other end of the airfoil directed radially outwards provides a contour, which is adapted such the through hole can be closed airtight by using an additional detachable fixation means. Therefore, in an assembled state the airfoil of the vane is detachable fixed at both ends in contrast to the embodiment according to state of the art shown in FIG. 2 in which the inner platform is spaced from the inner structures of the turbine stage respectively spaced from the inner combustor liner.
In another embodiment the outer end of the airfoil, which is named as other end directed radially outwards, can be non detachable connected, i.e. in one piece, with an outer platform having a platform shape which fits into the through-hole in the stationary component such that the outer platform closes the through-hole airtight by suitable fixation means.
In a further embodiment the airfoil of each vane has at its end directed radially inwards an inner platform or at least a little shape in the form of an inner platform which is spaced inwards to components of the turbine stage so that a cooling channel is limited through which a purge flow of cooling medium can be injected into the hot gas channel of the turbine stage. The outer end of the airfoil provides at least a contour which is adapted such the through hole can be closed airtight by using an additional detachable fixation means.
In all cases of embodiments according to the invention, it is possible to insert or remove the airfoil of the vane radially through the through-hole inside the stationary component.
In case of a fixed position, by at least the fixing means at the outer end of the airfoil, the airfoil of the vane stays in close contact or is connected in one piece with the inner platform which boarders the hot gas flow through the turbine stage towards the inner diameter of the hot gas flow channel of the turbine stage. On the other hand the outer platform which is connected with the airfoil in a flush manner or which is manufactured in one piece with the airfoil borders the hot gas flow channel radially outwards. All inner and outer platforms of the vanes of the first row being aligned adjacent to each other in circumferential direction limit an annual hot gas flow in the area of the entrance opening of the turbine stage.
In case of a detachable fixation between the inner end of the airfoil and the inner platform as mentioned before in connection with the first preferred embodiment the inner platform provides at least one recess for insertion the hook like extension of the airfoil at its radially inwards directed end so that the airfoil is fixed at least in axial and circumferential direction of the turbine stage. As it will be described later in reference to an illustrated embodiment the hook like extension has a cross like cross section, which is adapted to a groove inside the inner platform. The recess inside the inner platform provides at least one position for insertion or removal at which the recess provides an opening through which the hook like extension of the airfoil can be inserted completely only by radial movement. The shape of the extension of the airfoil and the recess in the inner platform is preferably adapted to each other like a spring nut connection.
For insertion or removal purpose it is possible to handle the airfoil only at its radially outwards directed end which is a remarkable feature for performing maintenance work at the turbine stage without the need of lift of the upper casing half of the turbine stage as will described later.
A further opportunity for repair work at the first turbine stage it is favorable that the inner platform is separately fixed to the inner structure. In a preferred embodiment the inner platform is detachably mounted to an intermediated piece, which is also detachably mounted to the inner structure respectively inner component of the turbine stage. Hereto the intermediate piece provides at least one recess for insertion a hook like extension of the inner platform for axially, radially and circumferentially fixation of the inner platform. Basically, the intermediate piece allows some movement of the inner platform in axial, circumferential, and radial direction. There are some axial, circumferential, and radial stops in the intermediate piece to prevent the inner platform from unrestrained movements. With the axial and circumferential stop the vane airfoil is not cantilevered but supported at the outer and inner platform. An additional spring type feature presses the inner platform against a radial stop within the intermediate piece, so that the airfoil can be mounted into the outer and inner platform by sliding the airfoil radially inwards from a space above the outer platform liner.
The connection techniques used for connecting the airfoil with the inner platform, the inner platform with the intermediate piece and the intermediate piece with the inner structure of the turbine stage are chose suitably such a worker can easily mount or dismantle each of the connections easily without the need of much mounting space.
Typically a turbine stage of a gas turbine arrangement is encapsulated by a casing in which at least one manhole is provided to get access for a worker to the inner section of the stationary components of the turbine stage. Inside the casing is enough space for a worker to mount or demount at least one vane by radially insertion and/or removal the airfoil through the through-hole of the stationary component. In case of removing a for example defective airfoil of a vane a worker has access to the fixation means which fixes the airfoil of the defective vane with the stationary component. After releasing the fixation means the worker has access to the radially outwards directed end of the airfoil so that the worker can handle the airfoil at its airfoil tip. Now it is possible to remove the airfoil at its extension radially out of the recess of the inner platform and to remove the airfoil completely out of the turbine stage through the through hole inside the stationary component.
Since all vanes of the first vane row are equipped with such fixation means inventively it is possible to remove one after the other all vanes out of the turbine stage.
For further maintenance work especially at the first row of blades it is possible to get a direct access by entering the space of the combustor through a further manhole, for example by removing the burner for getting access into the combustor through the burner opening. In a next step it is possible to remove the inner platform and following the intermediate piece to get a direct access to the first blade row.
Basically the inventive attachment of the vanes is not limited to vanes arranged in the first row of a gas turbine, so that all vanes of a gas turbine can be fixed at their outer end of the airfoil in a detachable manner for an easy inspection. More details are given in combination with the following illustrated embodiments.
BRIEF DESCRIPTION OF THE FIGURES
The invention shall subsequently be explained in more detail based on exemplary embodiments in conjunction with the drawings. In the drawings
FIG. 1 shows a rough sketch of a longitudinal section through a part of a first turbine stage with a combustor exit,
FIG. 2 shows a rough longitudinal section through the first turbine stage according to state of the art,
FIGS. 3 a , 3 b , 3 c , and 3 d show an airfoil with extension and an inner platform,
FIGS. 4 a and 4 b show a cross sectional and top view of an intermediate piece,
FIGS. 5 a and 5 b are sectional views through the radially outward directed end of the airfoil with fixation means to the outer platform,
FIGS. 6 and 7 are sketches to illustrate performing maintenance work on a stationary gas turbine and
FIG. 8 is an alternative airfoil with an inner platform spaced apart from stationary turbine component.
DETAILED DESCRIPTION
FIG. 1 shows a rough schematically longitudinal section of a first turbine stage 6 , which is downstream arranged to a combustor 4 . The turbine stage 6 provides a first row of vanes 1 , which is followed in axial flow direction by a first row of blades 2 . To get a direct access to the stationary components 13 of the turbine stage 6 inside a casing 17 encapsulating at least parts of turbine stage 6 as well parts of the combustor 4 at least one manhole 18 is provided which is lockable air tightly.
Each vane 1 of the first row of vanes is assembled in parts, so that the airfoil 1 ′, the inner platform 10 and the outer platform 9 are separate parts. In case of the embodiment shown in FIG. 1 it is assumed that the outer platform 9 of the vane is part of the stationary component 13 of the turbine stage. The outer platform 9 provides a through hole 19 , which is typically adapted to the largest cross section of the profile of the airfoil 1 ′ of the vane 1 . The radially outward directed end of the airfoil 1 ′ has a shape adapted to the shape of the through hole 19 so that the end of the airfoil tip closes the through hole 19 air tightly.
Further there are fixation means 20 (shown in FIG. 5 ) which connects the radially outwards end of the airfoil 1 ′ with the stationary component 13 respectively with the outer platform 9 . The radially inwards directed end of the airfoil 1 ′ provides a hook like extension 21 , which is inserted into the inner platform 10 , which is connected to an intermediate piece 22 being detachably fixed with inner structures of the turbine stage 6 .
The airfoil 1 ′ of the vane 1 is connected radially with its outer and inner end. In addition by separating the outer platform from the airfoil 1 ′ it is possible to design the outer platform 9 integrally with the outer combustor liner 15 ′ to remove the leakage line 14 ′ as explained in FIG. 2 . Of course, it is possible too to design the outer platform 9 and the outer combustor liner 15 ′ as separate parts, which can enclose a purge flow gap 14 ′ as in case of FIG. 2 .
On the other side the mating faces of the inner platform 10 and the inner combustor liner 15 are inclined more to aerodynamically better introduce the purge flow into the main flow 3 . The new design allows further an overlap of the inner platform 10 and the inner combustor liner 15 .
FIG. 3 a shows a side view of an airfoil 1 ′ of a vane having an end directed inwardly at which a hook like extension 21 is arranged protruding over the length of the airfoil 1 ′. The extension 21 has a cross like cross-section, which is illustrated in FIG. 3 b . The inner platform 10 , which is illustrated in FIG. 3 c , has a recess 21 ′ of cross like cross section for insertion the extension 21 only by radial movement. The depth of the recess 21 ′ is larger than the radial length of the extension 21 , so that radial movement of the extension 21 within the recess 21 ′ remains possible for example to compensate different thermal expansion effects between the turbine components. Due to the cross sectional shape of the extension 21 and the recess 21 ′, the airfoil is fixed axially and in circumferential direction.
FIG. 3 d shows a side view of the inner platform 10 , which also provides at its bottom face two hooks 34 for mounting in the intermediate piece 22 .
FIGS. 4 a and 4 b show a cross sectional view as well a top view of recesses inside an intermediate piece 22 . In case of the illustrated embodiment the intermediate piece 22 provides two separate recesses 24 each of the recesses can receive the hooks 34 of one inner plate 10 . So it is possible to fix at least one inner plate 10 at one inter mediate piece 22 . Each of the recesses 24 shown in FIG. 4 b has openings 25 to receive a hook 34 of the inner platform 10 , which typical has a T-like cross section. Further the recess 24 provides an axial groove 26 having also a T-cross section 27 as illustrated in FIG. 4 a shows a section view along the section line A-A. By sliding the T-shaped hooks 34 axially along the recess 24 a position can be reached in which the inner platform 10 is fixed radially, axially and in circumferentially direction.
FIGS. 5 a and 5 b illustrate sectional views of two alternative embodiments of a fixation means 20 for the outer directed end of an airfoil 1 ′. The embodiment shown in FIG. 5 a illustrates the outer platform 9 having a through-hole 19 providing a contoured rim surface 28 at which the outer end of the airfoil 1 ′ aligns with its contour 23 air tightly. To fix and press the outer end of the airfoil 1 ′ against the through hole 19 a fixation means 20 is used which is a bar 29 fixed by screws 30 onto the outer platform 9 by pressing the airfoil 1 ′ directed radially inwards.
In FIG. 5 b another sealing and fixing mechanism is discloses. Here the upper end of the airfoil 1 ′ has a protruding collar 33 which is pressed by the bar 29 into a nut like recess 31 inside the outer platform 9 in which a chord seal 32 is inserted. In the same way as in FIG. 5 a the bar 29 is pressed and fixed against the upper end of the airfoils by screws 30 .
For performing maintenance work inside the first turbine stage 6 first it is necessary to get an access to the space between the casing 17 and the stationary components 13 of the stationary turbine 6 , see FIG. 1 . A worker man has to open the man hole 18 above the first stage vane. In a second step the worker has to remove the fixation means 20 so that the airfoil 1 ′ can be radially drawn out of the gas turbine. In response to the extent of the maintenance work the worker can remove one vane or all vanes 1 in the before manner since all vanes are designed and fixed inside the first row of vanes in the same manner.
FIG. 6 illustrates the situation in which the vanes are removed completely out of the turbine stage 6 , which is shown by the open through-hole 19 inside the outer platform 9 . The worker man gains access into the space of the combustor 4 by a further manhole for example by demounting the burner arrangement from the combustor liner (not shown). Now the worker has access to the inner platform 10 , which can be removed by pressing down and moving in axial direction towards the combustor liner 15 . The inner platform 10 can then be tilted in upstream direction and removed downstream for final release. In a next step the intermediate piece 22 can also be removed completely out of the turbine stage 6 as illustrated in FIG. 7 . Now the worker has a direct access to the first stage blade 2 . Finally the first stage blade 2 can also be removed, if required it is possible to replace labyrinth sealing 35 , which between the intermediate piece 22 and the stationary components of the turbine stage, before reassembling the first turbine stage by carrying out the explain steps in reverse order.
FIG. 8 shows an alternative fixation of a vane 1 which provides an airfoil 1 ′, an inner platform 10 and a small fragment of an outer platform 10 in one piece. The inner platform 10 is spaced apart from the inner combustor liner 15 and limits a gap 14 through which a purge flow of cooling medium can be injected into the hot gas flow 3 . The outer platform 9 fits airtight in a through-hole 19 inside the stationary component 13 . The outer end of the outer platform 9 is pressed radially inwards by a bar 29 which is fixed by at least two screws 30 at the stationary component 13 . The size and shape of the through-hole 19 has to be adapted to the largest diameter of the vane 1 , which may be in the section of the inner platform 10 to ensure that the whole vane 1 can be removed completely and easily by radial movement only. All reference signs in FIG. 8 being not mentioned yet concern to components, which are explained in detail in connection with FIG. 2 .
The inventive stationary gas turbine arrangement leads to couple of significant advantages as listed in the following:
a) Enabling 1 st stage disassembly while casing and rotor are not lifted—only manholes must be opened. This is equivalent to a significant reduction in engine outage time. In turn this is a considerable commercial benefit for the gas turbine operating company.
b) Enabling of replacement of individual airfoils, individual inner diameter platforms and individual 1 st stage blades. This is equivalent to a significant reduction in engine outage time. In turn, this is a considerable commercial benefit for the gas turbine operating company.
c) Due to integration of outer platform into the outer combustor liner cooling air leakage is reduced because gap between combustor liner and vane platform disappears being equivalent to a performance increase.
d) Enabling of reducing aerodynamic losses due to better alignment of purge and main flow from gap between combustor liner and vane platform into the main flow being equivalent to a performance increase.
e) Labyrinth seal can be replaced easily.
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The invention refers to a stationary gas turbine arrangement with at least one turbine stage that includes at least a first row of vanes being mounted at a stationary component arranged radially outside of the first row of vanes and extending radially into an annular entrance opening of the turbine stage facing a downstream end of a combustor. Further a method for performing maintenance work on a stationary gas turbine is described. The invention is characterized in that the stationary component provides for each vane a radially orientated through-hole designed and arranged for a radial insertion and removal of the vane, and each of said vanes comprises an airfoil having at its one end directed radially outwards a contour being adapted to close the through-hole airtight by a detachable fixation means.
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This application is a Continuation of prior U.S. application Ser. No. 08/559,927 Filing Date Nov. 11, 1995, now abandoned, which is a continuation of application Ser. No. 08/116,874 Filing Date: Sep. 3, 1993 now abandoned.
TECHNICAL FIELD
This application relates to a powder useful in thermal spraying of coatings, particularly for anti-corrosion coatings for metal parts.
BACKGROUND OF THE INVENTION
Chromium carbide coatings have been made by thermal spraying for many years. One such coating is made of Cr 3 C 2 particles in a nickel-chromium alloy binder. Other carbides have also been used with nickel-chromium. However, for certain types of high temperature applications, chromium carbide is the only practical choice. For example, carbide in a cobalt binder can be used as an anti-erosion coating for many aircraft part surfaces, but lacks sufficient heat resistance for use in high temperature zones. Tungsten carbide titanium carbide solid solution with a nickel binder is somewhat better, but still inadequate at high temperatures.
During thermal spraying, the powder is heated, resulting in full or partial melting, and then sprayed onto the surface to be coated. The powder is generally a simple blend of chromium carbide powder with nickel chromium powder, most commonly a 75 wt. % chromium carbide/25 wt. % Ni--Cr mixture or 80 wt. % chromium carbide/20 wt. % Ni--Cr mixture, but blends ranging from 7 wt. t to 25 wt. % Ni--Cr are in common use. In general, during spraying the chromium carbide remains solid while the nickel-chromium alloy melts, resulting in a coating in which the carbide particles are embedded in nickel-chromium. If the carbide particles are relatively large, the resulting coating will have poor smoothness.
The nickel-chromium alloy used in these blends has been an 80 wt. % nickel/20 wt. % chromium alloy (e.g., NICHROME). The mixture is most commonly applied by a non-transferred plasma arc process. With the advent of the high velocity oxy-fuel (HVOF) spraying process, however, a need for new chromium carbide coating materials became apparent because the HVOF process does not work well with known chromium carbide/Ni--Cr alloy powder blends. The HVOF process tends to segregate the blend into its components, forming an unsatisfactory coating.
To overcome this problem, a prior art powder marketed by the assignee pre-blends 80 wt. % chromium carbide particles with 20 wt. % of the Ni--Cr (80:20) binder. The particles consists essentially of a chromium carbide core coated at least partially with a layer consisting essentially of a nickel-chromium alloy. Successive steps of sintering, grinding and classification are used to form the particles. Pre-blended particles prepared in this manner provided some improvement in performance, but the coating formed by HVOF spraying still had difficulty achieving both good smoothness and high erosion resistance properties.
The present invention provides an improved powder capable of producing coatings have much better erosion resistance properties in comparison to the foregoing known powder having a similar composition.
SUMMARY OF THE INVENTION
A powder for use in a thermal spraying coating process according to one aspect of the invention comprises particles consisting essentially of a metal carbide core coated at least partially with a layer consisting essentially of a nickel-chromium alloy containing the metal carbide dissolved therein. The particles are formed by heating a mixture of fine starting particles of the metal carbide in the presence of the nickel-chromium alloy under conditions effective to cause a portion, preferably 60 to 90 wt. %, of the starting metal carbide to dissolve in the Ni--Cr alloy. The amount of the original carbide particle that remains undissolved prior to spraying is difficult to estimate, but is generally from about 10 to 90 wt. % of that originally present, especially 10 to 40 wt. %, the precise amount depending on the smoothness of the coating desired and the spraying conditions.
The relative amounts of the carbide and the Ni--Cr alloy are selected so that, upon cooling of the sprayed coating, substantially all of the carbide remains in solution in the Ni--Cr alloy. If the amount of carbide is too great, carbide will precipitate out when the coating cools, forming a second phase that weakens the coating and lowers erosion resistance. Coatings formed according to the invention show an unexpectedly large increase in both smoothness and erosion resistance as compared to closely similar coatings, particularly coatings formed from the 80:20 chromium carbide/Ni--Cr alloy prior art powder described above, wherein the amount of carbide used was so great that a substantial portion of the carbide did not remain in solution.
According to a foregoing aspect of the invention, the carbide particles are not entirely pre-dissolved in the Ni--Cr alloy. If dissolution is complete, the resulting composite alloy has a higher overall melting point and may become more difficult to spray. Accordingly, it is preferred that only a portion of the metal carbide, preferably chromium carbide, be pre-dissolved in the Ni--Cr alloy. However, in accordance with an alternate embodiment of the invention suitable for plasma spraying, the powder may be prepared as set forth above except that more than 90 wt. %, up to and including 100 wt. %, of the starting carbide particles are dissolved. As the amount dissolved approaches 100 wt. %, the core essentially disappears.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The powders of the invention can be referred to as alloyed, composite, or bonded metal carbides. Where the metal is chromium, these materials are formed by a process which creates particles containing both phases, namely a Cr 3 C 2 core which has been covered by a complete or partial coating of the Ni--Cr binder alloy containing dissolved chromium carbide. Unlike prior spraying processes such as plasma spraying using a DC arc, or D-gun spraying, which operates by combustion of acetylene on a pulse basis, HVOF spraying operates in a continuous, high-velocity stream. The HVOF stream tends to separate the chromium carbide from the Ni--Cr alloy, resulting in isolated areas of each on the coating surface, or layering of one on the other, resulting in an inferior coating. It is difficult to melt and soften chromium carbide, so that very little is deposited.
The composite particles according to the invention can be applied without separation by HVOF spraying to surfaces such as aircraft parts made of hard metals such as steel or titanium alloys. A coating of the invention formed by HVOF spraying can have both low surface roughness and high resistance to erosion. Normally, increasing one of these characteristics decreases the other. For example, decreasing the particle size makes the resulting coating smoother, but the coating erodes more readily. In typical coatings formed using a finer powder, the resulting coating has higher stresses, rendering the particles more susceptible to oxidation and thereby increasing erosion.
Both erosion and surface roughness must meet prescribed specifications of aircraft manufacture or the coating will not be usable. For example, blades for use in stages 6 to 12 of a 12-stage rotary compressor for a 737 jet engine (CFM 56) must have a roughness of no more than about 80 Ra, particularly 30-80 Ra, wherein Ra refers to the average difference in microinches between peaks and valleys in the coating. Erosion loss, as measured by sandblasting with 600 grams of fine white alumina, 230 grit, at 50-60 psi, should be 170 micrograms/gram or less, preferably 125 mg/g or less.
In making the powder of the invention, commercially available chromium carbide and Ni--Cr powders are transformed from a simple powder blend to a composite powder as described above. This may be accomplished by, for example, spray-drying chromium carbide particles with Ni--Cr. A preferred process combines the particles by solid-state sintering. During sintering, the outsides of the metal carbide particles dissolve in the surrounding Ni--Cr alloy. However, the sintering conditions are controlled as described below to prevent complete dissolution. The resulting alloy of the metal carbide and the Ni--Cr alloy deposited on the outsides of the metal carbide particles is a eutectic having a higher melting point than the starting Ni--Cr alloy. Upon thermal spraying, the remainder of the metal carbide melts, providing a coating with superior erosion resistance because it has no weak spots in the form of precipitated metal carbide or unmelted metal carbide particles. The coating made using such an alloy according to Example 1 below exhibited a single phase, an Ni--Cr--C alloy nearly free of carbide particles when examined under a microscope.
To prepare the powder of the invention, the particulate metal carbide is first blended with a nickel-chromium alloy to form a mixture. Regardless of the method of preparation, the use of fine starting metal carbide particles is important. If the starting carbide particles are too coarse, the desired solution does not form. If the starting carbide particles are too fine, the chrome carbide becomes pyrophoric and is difficult to handle. Chromium carbide particles from 1 to 10 microns in size have proven most effective.
The mixture of powders is sintered to form a solid mass, and preferably permitted to cool. The solid mass is then ground back into a powder form, and the powder is classified to obtain a powder the desired particle size distribution.
The mixture is preferably sintered at a temperature in the range of 1200° to 1500° C. for about 0.3 to 3 hours, most preferably 1250°to 1450° C. for about 30 to 90 minutes. Excessive heat or time (or both) causes large crystals to form which adversely affect the properties of the coating. On the other hand, insufficient sintering means the advantages of the invention are not obtained. The temperature of the mixture during sintering generally remains lower than the melting point of the two components, for example 1700°-1800° C. for chromium carbide and about 1400° C. for Ni--Cr (solution of Cr in Ni). Sintering may be carried out without external application of pressure.
The sintered and cooled mass, in the form of a fused ingot, is then returned to powder form by grinding. This is readily accomplished by one or more rough-crushing steps in which the ingot and large fragments thereof are broken up into a broad range of different-sized particles, and then a milling step in which coarse particles are further reduced in size to provide a fine particle mixture with particles ranging in size from about 1 to 100 microns.
The milled particles are then classified, preferably using a conventional air classifier, to obtain the desired particle size distribution. A broad range of particle sizes from about 2 to 100 microns can be used in thermal spraying, and classification may be omitted if grinding results in the desired particle distribution. For plasma spraying of the powder of the invention, particle sizes ranging from 44 to 100 microns are most preferred, in comparison to a range of 3 to 30 microns normally used for a chromium carbide powder/Ni--Cr alloy powder in plasma spraying.
As to HVOF spraying, in contrast to the mixtures of chromium carbide and Ni--Cr particles of the prior art used for compressor blade coatings, wherein the sizes range from about 10 to 40 microns with a mean of 25-30 microns, a range according to the invention of about 2 to 44 microns with a mean of around 9 to 13, especially 9-11 microns according to the invention results in a smoother coating which, surprisingly, has erosion resistance as good or better than the prior alloy with the much higher overall particle size. Sprayability is generally best at an intermediate size range of about 15-44 microns, and this range is preferred for applications wherein a high as-sprayed finish is not required. For example, valve components can be coated according to this embodiment of the invention and then ground and polished to obtain a higher finish.
For purposes of the invention, a "mean" refers to a particle size at which approximately half the particles have greater particle sizes and half have lesser sizes. Such a mean also closely approaches a weighted average particle size. "Particle size" for purposes of the invention refers to the diameter of a roughly spherical particle, or the largest dimension of a non-spherical particle.
The finished powder according to one embodiment of the invention useful in high temperature applications consists essentially of 4 to 7 wt. % Ni, 11 to 13 wt. % C, up to about 5 wt. % other elements (usually impurities) such as one or more of Fe, Mn, Si, W, Co, Mo and Zr, and the balance Cr (typically from 79 to 83 wt. %). Ranges of 4 to 6 wt. % Ni, 11.5 to 12.5 wt. % C, up to about 2.5 wt. % impurities are preferred to obtain optimum surface smoothness and erosion resistance. The 80:20 prior art powder described above contained about 16 wt. % Ni, 10.5 wt. % C, up to about 3 wt. % other elements and the balance Cr (about 70.5 wt. %).
The metal carbide used in the invention is most preferably chromium carbide or a mixture thereof with another metal carbide, or a carbide having comparable properties, such as titanium carbide. The Ni--Cr alloy used in the invention consists essentially of nickel and chromium but may contain substantial amounts of other elements. For example, the alloy used in Example 2 below contained 7 wt. % iron and 4 wt. % niobium, in addition to Ni and Cr. Niobium in an amount of from about 1 to 8 wt. % is a useful addition insofar as it inhibits grain growth in the coating.
The relative amounts of the starting powders and the amount of Cr in Ni are adjusted as needed to provide compositions wherein the metal carbide is partly dissolved in the Ni--Cr alloy prior to spraying, and the amount of carbide is such that it substantially completely dissolves in the Ni--Cr alloy upon thermal spraying and remains dissolved in the coating once cooled. These amounts will vary substantially depending on the carbide used and exact makeup of the Ni--Cr alloy; compare the results of Examples 1 and 2 below.
In a preferred embodiment wherein the metal carbide is chromium carbide and the Ni--Cr alloy is the one described above containing 4 to 7 wt. % Ni, 11 to 13 wt. % C, up to about 5 wt. % other elements, and the balance Cr, the amounts of starting chromium carbide and Ni--Cr alloy preferably vary from 92 to 85 wt. % Cr 3 C 2 to 8 to 15 wt. % Ni--Cr. The relative amounts of Ni and Cr in the Ni--Cr alloy for this embodiment differ from the standard 80:20 NICHROME material. The weight ratio of Ni:Cr ranges from 70:30 to 50:50. In Example 1 below, a 50:50 Ni--Cr material was used in an amount of about 12 wt. % relative to 88 wt. % Cr 3 C 2 . Above 70 wt. % Ni, the amount of Cr in the alloy becomes insufficient to completely dissolve the carbide. At less than 50 wt. % Ni, formation of Ni--Cr ends and an undesirable second phase forms. However, if substantial amounts of other elements such as iron or niobium are present, the foregoing ranges will be different, as illustrated by Example 2 below.
The powder of this invention was developed for forming an erosion coating for an aircraft turbine. However, other useful applications include oil well valves and rig components, steam pipes and valves, and other components wherein surfaces are regularly exposed to a high temperature gas or liquid that can cause erosion. Some erosion applications, unlike air foil erosion coatings, will not need a fine finish, in which case larger particle sizes can be used.
The following examples illustrate the invention.
EXAMPLE
The starting materials consisted of chromium carbide (Cr 3 C 2 ) powder and a nickel-chromium alloy powder. The specification of each was as follows:
Chromium Carbide
______________________________________Size<11 microns 100%Chemistrycarbon 12% minsilicon 0.25 maxiron 0.30 maxothers 1.0 maxchromium balance______________________________________
Nickel-chromium alloy:
______________________________________ Size <31 microns 80% Chemistry chromium 49-50% nickel 49-50% others 1.0 max______________________________________
The raw materials were blended together at a ratio of 90 wt. % chromium carbide to 10 wt. % nickel-chromium alloy. The blend was placed in graphite saggers each painted with a calcium carbonate wash to prevent carbon pickup. The saggers were pushed through a moly-wound muffle furnace in a hydrogen-nitrogen atmosphere. The heat zone of the furnace was about 36 inches long, and each sagger moved through the heat zone in about one hour. The temperature at the center of the heat zone was maintained at 1300° C.±25° C.
Upon exiting the heat zone, the sagger entered a water jacketed cooling zone about 5 feet in length. The sagger and material were cooled to about 100° C. before exiting the furnace. Flame curtains were maintained at both the entrance and exit of the furnace to protect the product from oxidation. The product that emerged from the furnace was in the form of an ingot about 18 inches long, 3 inches wide, and 1-2 inches thick.
The ingots were then rough-crushed to pieces less than about 1 inch in size with a large jaw crusher. A smaller jaw crusher was then used to reduce the average particle size to less than about 0.25 inch. The crushed product was then fed into a high energy vibrating tube mill of a type effective to minimize iron contamination to reduce the particle size further. After milling, the powder was screened to -270 mesh, and the oversized material was returned to the mill for further crushing. The -270 material was air classified using a VORTEC C-1 Series Classifier to final product size. The exact size was selected based on the end use of the intended coated product, namely blades for use in stages 6 to 12 of a 12-stage rotary compressor for a 737 jet engine.
Six samples A-F according to the invention had compositions and approximate particle size distributions as set forth in Table 1 below. For the size distributions of part B, the values given for each sample represent the percentage of the total particles having particle sizes finer than the micron size in the left column. In part C, mv=mean value, and the values aligned with each percentage indicate a cutoff size at which the stated percent of the particles have that micron size or less.
TABLE 1______________________________________A. CompositionSample A B C D E F______________________________________Cr 79.19 82.50 80.03 80.67 81.24 81.46N 5.55 4.12 6.17 5.71 5.02 4.6Mn 0.04 0.02 0.03 0.03 0.03 0.03Fe 2.3 0.7 1.19 0.95 1.1 0.87Si 0.01 0.01 0.08 0.12 0.07 0.05C 12.31 11.76 11.69 12.02 12.02 12.43OT* 0.6 0.89 0.81 0.5 0.52 0.56B. Size DistributionMicrons44 100 100 100 100 100 10031 100 100 100 96.2 100 97.722 96.6 100 100 91.1 100 94.816 87.4 92.4 93.6 80.9 97.5 87.411 56.1 68 65.5 57.1 81.4 62.37.8 28.7 37.3 35.4 32.1 56.2 365.5 11.3 15.9 13.9 13.9 31.5 16.83.9 3.5 6.5 4.3 4.9 14.3 6.92.8 0.6 0.7 0.5 0.6 3 1.4C. Sie Distribution Summarymv 10.77 9.55 9.7 11.97 7.81 10.7490% 17.38 15.49 15.35 21.32 13.65 18.0950% 10.28 9.11 9.34 10.08 7.22 9.4910% 5.22 4.48 4.83 4.79 3.47 4.39______________________________________
OT* refers to other elements. Samples A-F were applied by HVOF spraying using 160 psi oxygen, 100 psi hydrogen to stainless steel test pieces using a modified JET-KOTE sprayer from Stellite. The resulting coatings were tested for erosion by sandblasting with 600 grams of fine white alumina, 230 grit, at 50-60 psi.
The coatings made using Samples A-F according to the invention were tested for Rockwell 15N hardness (15N), diamond pyramid hardness or microhardness (DPH), erosion loss (E w ) as described above, and smoothness (Ra) in microinches. Desirable levels for aircraft coatings are a 15N hardness of at least 80, a microhardness of at least 750, erosion loss of less than 125 mg/g, and smoothness of less than about 80 Ra (microinches). Table 2 summarizes the results for the samples prepared using the powder of the invention:
TABLE 2______________________________________Sample Mean 15N DPH E.sub.w Ra______________________________________A 10.77 90.9 816.8 109.3 76.1B 9.55 91.2 876.7 10.4 74.9C 9.70 90.8 831.5 109.9 73.8D 1.97 91.2 839.7 108.1 80.2E 7.81 107.3 59.9F 10.74 91.0 828.7 104.2 74.8High 10.77 91.2 876.8 10.4 76.1Low 9.55 90.8 828.7 104.2 73.8Range 1.22 .4 48.1 6.2 2.3Average 10.19 91.0 853.4 108.4 74.9______________________________________
As these results indicate, the samples according to the invention had both excellent smoothness and erosion resistance. By comparison, the known 80:20 powder discussed above and variations thereon that were tested were comparable in most characteristics, but had smoothness values ranging from 75 to 90 Ra and erosion values (E w ) of about 125 to 148 mg/g. The large improvement in erosion resistance of the samples according to the invention is quite surprising in view of the comparatively small difference in the overall composition of the coatings.
EXAMPLE 2
Another powder according to the invention was prepared using substantially the same procedure as Example 1, except that the starting powder composition was 90 wt. % chromium carbide and 10 wt. % of an Ni--Cr alloy containing 20 wt. % Cr, 4 wt. % Nb, 7 wt. % Fe, traces of C and Mn, and 62.5 wt. % Ni. When HVOF sprayed and tested for erosion, the result was 117 micrograms/gram, with satisfactory smoothness suitable for high-temperature compressor blade applications. In this example, as in Example 1, the carbide was partly dissolved in the Ni--Cr alloy prior to spraying, and the amount of carbide was such that it substantially completely dissolved in the Ni--Cr alloy upon spraying and remained dissolved in the coating.
It will be understood that the foregoing description is of preferred exemplary embodiments of the invention, and that the invention is not limited to the specific forms shown. Modifications may be made in the composition and its method of preparation and use without departing from the scope of the invention as expressed in the appended claims.
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A powder for use in a thermal spraying coating process comprises particles consisting essentially of a metal carbide core coated at least partially with a layer consisting essentially of a nickel-chromium alloy containing the metal carbide dissolved therein. The particles are formed by heating a mixture of fine starting particles of the metal carbide in the presence of the nickel-chromium alloy under conditions effective to cause a portion, preferably 60 to 90 wt. %, of the starting metal carbide to dissolve in the Ni--Cr alloy. In an alternate embodiment suitable for higher temperature application, more than 90 wt. % of the starting carbide particles are dissolved. As the amount dissolved approaches 100 wt. %, the core essentially disappears. Coatings formed according to the invention show an unexpectedly large increase in both smoothness and erosion resistance.
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The present application is a divisional (and claims the benefit of priority under 35 USC 121) of U.S. patent application Ser. No. (“USSN”) 09/107,380, filed on filed Jun. 30, 1998 now 6,043,068, which claims the benefit of priority under 35 U.S.C. § 119 of Japanese patent application number 17762/1997, filed Jul. 2, 1997. These applications are explicitly incorporated herein by reference in their entirety and for all purposes.
FIELD OF THE INVENTION
The present invention relates to magnetic carriers in which microorganisms requiring carriers for their growth in the step of treating wastewater have been immobilized, a process for producing the carriers and a method of treating wastewater.
BACKGROUND OF THE INVENTION
For wastewater treatment, methods using microorganisms-immobilized carriers have been put to practical use widely. However, it is revealed that there are drawbacks such as damages of carriers and microorganisms caused by stirring in a carrier-suspending chamber, pressure loss in a fixed-bed biomembrane chamber, outflow of carriers in a fluidized-bed biomembrane chamber, and carrier floating caused by gases generated in the carriers. To overcome these drawbacks, it is effective to control the movement of carriers by utilizing magnetic force to stably retain a predetermined amount of carriers in a treatment chamber.
The magnetic carriers have been developed for the purpose of rapid separation and recovery of immobilized materials, e.g. biologically active substances such as enzymes etc. and animal cells etc., by magnetism from the outside. For example, JP-A No. 1102/1990 and JP-B No. 16164/1993 disclose immobilized magnetic carriers in which biologically active substances etc. are immobilized by first forming a magnetic body-containing nucleus, then laminating a polymer layer on the outside thereof, and immobilizing biologically active substances etc. onto the polymer layer of the magnetic carriers by an adsorption method, covalent bonding method, ionic bonding method, entrapment method, cross-linking method etc. For such magnetic carriers, it is reported that the thickness of the polymer layer should be reduced to 30% or less of the diameter of carriers as a whole to permit the ultra-paramagnetic body inside the carriers to work sufficiently (JP-B No. 16164/1993). However, in the case of microorganisms-immobilized magnetic carriers for wastewater treatment, if the thickness of the polymer is limited to 30% or less, the amount of microorganisms to be immobilized thereon is limited, and thus the polymer layer with such thickness does not appear to be effective.
Further, these conventional magnetic carriers are mainly directed to separation and recovery, so a process for their production includes adjustment of the content of the ultra-paramagnetic body, adjustment of specific gravity, formation of the polymer layer etc. and is thus complicated. On the other hand, the separation and recovery of the microorganisms-immobilized carriers is a secondary object in wastewater treatment, so there is demand for a simple and economically advantageous production process in order to eliminate these complicated steps.
SUMMARY OF THE INVENTION
An object of the present invention is to provide microorganisms-immobilized carriers with a high amount of microorganisms immobilized for use in wastewater treatment, the movement of which is controllable in a treatment chamber by magnetic force.
Another object of the present invention is to provide a process for efficiently producing said carriers.
A further object of the present invention is to provide a method for efficiently treating wastewater.
The present invention relates to microorganism-immobilized magnetic carrier comprising an ultra-paramagnetic body and microorganism entrapped in a polyacrylamide gel. In place of said polyacrylamide gel, other polymer gels such as polyvinylalcohol (PVA) gel can be used.
Further, the present invention relates to a process for producing the microorganism-immobilized magnetic carriers as, which comprises passing an aqueous solution (A) containing acrylamide, a gelation promoter, sodium alginate and an ultra-paramagnetic body between an outer and an inner tubes in a double-tubular nozzle consisting of an outer tube and an inner tube while passing a microbial suspension (B) through said inner tube to mix said aqueous solution (A) with said suspension (B) at the top of said double-tubular nozzle to form droplets, and dropping said droplets into an aqueous solution (C) containing calcium formate.
Furthermore, the present invention relates to a method for treating wastewater, in which said microorganisms-immobilized magnetic carriers are used.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A to FIG. 1C are drawings illustrating the outline of a method of utilizing the microorganisms-immobilized magnetic carriers of the present invention in batch treatment of wastewater.
FIG. 2 A and FIG. 2B are drawings illustrating the outline of a method of utilizing the microorganisms-immobilized magnetic carriers of the present invention in fluidized-bed treatment of wastewater.
FIG. 3 A and FIG. 3B are drawings illustrating the outline of a method of utilizing the microorganisms-immobilized magnetic carriers of the present invention in fluidized-bed treatment of wastewater.
FIG. 4 A and FIG. 4B are drawings illustrating the outline of a method of utilizing the microorganisms-immobilized magnetic carriers of the present invention in fixed-bed treatment of wastewater.
FIG. 5A to FIG. 5C are drawings illustrating the outline of a method of utilizing the microorganisms-immobilized magnetic carriers of the present invention as improving materials for wastewater treatment or as seeding materials.
FIG. 6 is a drawing illustrating the outline of a method of utilizing the microorganisms-immobilized magnetic carriers of the present invention in a mixed culture system for treatment of wastewater.
FIG. 7 is a drawing illustrating the outline of a method of utilizing the microorganisms-immobilized magnetic carriers of the present invention in wastewater treatment using an extrusion-type treatment chamber.
FIG. 8 is a graph showing a change with time in removal of nitrate nitrogen by porous denitrificater-immobilized magnetic carriers and non-immobilized denitrificater respectively.
FIG. 9 is a graph showing a change with time in removal of nitrate nitrogen by porous denitrificater-immobilized magnetic carriers.
FIG. 10 is a graph showing a change with time in concentration of nitrate nitrogen by porous denitrificater-immobilized PVA magnetic carriers which contain 10 g/L (dry base) of denitrificater and 15 g/L of magnetite. The culture was degassed with the helium gas.
The meanings of symbols are as follows: 1, magnetic carriers; 2, treatment chamber; 3, magnet; 4, magnetic coil; 5, metal core; 6, culture chamber; 7, electromagnet; 8, partition plate; and 9, permanent magnet.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
The microorganisms-immobilized magnetic carriers of the present invention comprise an ultra-magnetic body and microorganisms entrapped in polyacrylamide gel. When acrylamide monomers are polymerized in an aqueous solution in the presence of a gelation promoter, they form porous polyacrylamide gel. The resulting gel serves as carriers which can immobilize a large amount of microorganisms and have a shape suitable for growth of microorganisms as well as for release of generated gases, thus being advantageous for wastewater treatment etc.
The microorganism-immobilized magnetic carriers containing PVA gel in place of said polyacrylamide gel can also be used for the same purpose. Such magnetic carriers can be produced using PVA in place of said acrylamide monomer. In this case, if beads are formed by the freezing method described below, the gelation promoter is not necessary.
The ultra-paramagnetic body is a magnetic body which, like fine particles of a ferromagnetic body and ferrimagnetic body, is free of residual magnetization even if once placed in a magnetic field. Thus, unlike a usual magnetic body, they do not attach to each other after taken from a magnetic field. This property is preferable for wastewater treatment, and such an ultra-magnetic body includes fine powder of iron oxide such as magnetite, ferrite etc. Their preferable particle diameters are usually in the range of about 100 Å to 1 μm.
The microorganism is not particularly limited, so long as it can be used in wastewater treatment. For example, activated sludge or anaerobically digestible sludge can be used. Such sludge can be collected from, for example, a sewage disposal plant.
When the microorganism-immobilized magnetic carriers of the present invention are used in fixed-bed treatment or fluidized-bed treatment, they are preferably in the form of spherical beads. In this case, the diameters of beads are preferably 2.0 to 5.0 mm.
The microorganism-immobilized magnetic carriers in the form of spherical beads of uniform size can be produced in, for example, the following manner using a double-tubular nozzle consisting of an outer tube and an inner tube inserted into said outer tube.
An aqueous solution (A) containing acrylamide, a gelation promoter, sodium alginate and an ultra-paramagnetic body is passed between the outer and inner tubes in the double-tubular nozzle. At the same time, a microbial suspension (B) is passed through the inner tube of the double-tubular nozzle. They are mixed instantaneously at the outlet of the nozzle to form droplets. The inner diameter of the outlet of the outer tube is preferably 2.0 to 3.0 mm. The inner diameter of the outlet of the inner tube is preferably 1.0 to 1.5 mm. The difference between the inner diameter of the outer tube and the outer diameter of the inner tube is preferably at least 0.3 mm. The flow rate of the aqueous solution (A) and the suspension (B) is controlled so that they form droplets in the outlet of the nozzle. The supplied suspension (B): aqueous solution (A) ratio in volume is controlled preferably at a ratio of about 3:1 to 5:4, more preferably about 5:2.5 to 5:3, using, for example, a roller pump.
The gelation promoter to be added to the aqueous solution (A) includes cross-linking agents such as N,N′-ethylene-bis-acrylamide etc. and polymerization initiators such as N,N,N′,N′-tetraethylethylenediamine etc. These can be used singly or in combination thereof. In particular, a combination of N,N′-ethylene-bis-acrylamide and N,N,N′,N′-tetraethylethylenediamine is preferably used. The concentration of acrylamide monomers in the aqueous solution (A) is preferably 15 to 17% (w/v). The amount of N,N′-ethylene-bis-acrylamide employed is preferably 4.0 to 5.5 parts by weight for 100 parts of acrylamide. The amount of N,N,N′,N′-tetraethylethylenediamine employed is preferably 6.0 to 7.0 parts by weight for 100 parts of acrylamide.
Sodium alginate is added to the aqueous solution (A) so that when the above-mentioned droplets are dropped into the aqueous solution (C) containing calcium formate, a film of sodium alginate is instantaneously formed to give beads. The concentration of sodium alginate in the aqueous solution (A) is preferably 0.5 to 0.9% (w/v).
The amount of the ultra-paramagnetic body added to the aqueous solution (A) varies depending on the type of polymer employed and the forming method. When polyacrylamide gel is used as the polymer, the concentration of the ultra-paramagnetic body in the aqueous solution (A) is preferably 1 to 3% (w/v). When PVA gel is used as the polymer, the final concentration of the ultra-paramagnetic body in beads is preferably 10 to 50 g/L.
The suspension (B) includes, for example, concentrated sludge with volatile floating materials at a content of about 0.5 to 4.0%, preferably about 1 to 3%, obtained by centrifugation-sedimenting activated sludge collected from a sewage disposal plant.
Droplets formed at the outlet of the nozzle are dropped into the aqueous solution (C) containing calcium formate. The concentration of calcium formate in the aqueous solution (C) is preferably 2.0 to 4.0% (w/v). For the purpose of strengthening a film on beads, ammonium persulfate etc. are preferably added to the aqueous solution (C). In this case using ammonium persulfate, the concentration of ammonium persulfate in the aqueous solution (C) is preferably 0.3 to 0.6% (w/v). When the droplets are dropped, a film of calcium alginate is formed instantaneously to give granular beads. In a mixture of the aqueous solution (A) and the suspension (B) entrapped in said film of calcium alginate, acrylamide monomers are cross-linked with cross-linking agents such as N,N′-ethylene-bis-acrylamide etc. to be polymerized to form a gel, while the ultra-paramagnetic body and the microorganisms are entrapped in the gel. This reaction is usually completed in about 30 minutes to 1 hour. In this manner, the microorganism-immobilized magnetic carriers of the present invention entrapped in a film of calcium alginate is obtained.
If PVA gel is used in place of polyacrylamide gel as the polymer, the droplets are dropped into the aqueous solution (C) to form spherical beads which are immediately frozen and left as such, whereby cross-linking of the polymer and entrapped immobilization of microorganisms can be effected. This method is called the freezing method, which is known to those skilled in the art. If this freezing method is used, the gelation promoter is not needed.
The film of calcium alginate formed outside the carriers can be removed by dissolving it in phosphate buffer etc., whereby porosity of the carriers can be improved.
In producing the microorganism-immobilized magnetic carriers, it is preferable for the aqueous solution (A) and the aqueous solution (C) to be previously cooled at about 3 to 5° C. in order to prevent damage to the microorganism caused by chemical reaction heat.
After the microorganism-immobilized magnetic carriers of the present invention are produced, the microorganism is initially retained in the inside of the carriers. However, as waste-treatment etc. proceeds, the microorganism is attached and grows on the porous surface of the carriers. When treatment efficiency has reached a steady state, a film of microorganisms has been formed even on the surface of the carriers.
Wastewater can be treated efficiently by using the microorganism-immobilized magnetic carriers of the present invention. The method of treating wastewater is not particularly limited, which includes the conventional methods such as the batch treatment method, the fixed-bed treatment method and the fluidized-bed treatment method. The microorganism-immobilized magnetic carriers of the present invention can be used effectively in any of the conventional methods.
For example, if the microorganism-immobilized magnetic carriers of the present invention are used in batch treatment, the magnetic carriers suspended in a batch treatment chamber can be aggregated in a short time by applying a magnetic field from the bottom of the treatment chamber, as shown in Example 3 below. Thereby, the time for the aggregation/precipitation step can be reduced significantly. In addition, the amount of treated water or sludge to be drawn can also be set at a predetermined amount. In this manner, complicated steps such as the management of treated water and sludge and the operation of solid-liquid separation, which conventionally rely on the experience of the manager, can be omitted.
Further, for example, as shown in Examples 4 and 5 below, the microorganism-immobilized magnetic carriers of the present invention can be moved without stirring said magnetic carriers in a treatment chamber by applying a magnetic field from the outside of the treatment chamber. Thereby, the carriers and microorganisms can be prevented from damage caused by a stirring blade or the shear strength of a water stream etc. Therefore, although a considerable level of physical strength is conventionally required for such carriers so as to be resistant to stirring in suspending carriers, such high level of strength is not required for the carriers of the present invention. Further, a fluidized-bed biomembrane can be formed by moving the carriers constantly or at short intervals. The magnetic carriers can also be retained in a treatment apparatus by generating downward magnetic force by means of a magnetic coil. Thereby, pipe clogging, pump trouble etc. caused by an outflow of the carriers can be prevented.
In addition, for example, as shown in Example 6 below, formation of a short cut pathway for wastewater can be prevented and treatment efficiency is improved by giving vibration to a fixed bed of the microorganism-immobilized magnetic carriers of the present invention at predetermined intervals. By this vibration, sludge residue is also shaken off, thus clogging of the fixed bed as well as pressure loss can be prevented.
Further, for example, as shown in Examples 3 and 4 below, separation of air bubbles generated from the carriers can be promoted by forcibly immersing the magnetic carriers in treatment water by applying a magnetic field from the outside of the treatment chamber. Thereby, the individual carriers or the whole of the biomembrane can be prevented from floating.
Further, for example, as shown in Example 7 below, if the microorganism-immobilized magnetic carriers for wastewater treatment, while being cultured, is stocked in an arbitrary culture chamber, the magnetic carriers can be easily recovered as necessary by a strong electromagnet etc. Treatment efficiency can be improved by transferring the recovered magnetic carriers to another existing treatment chamber, and further, the carriers can also be used as seeding materials for another treatment.
Further, for example, as shown in Example 8 below, the carriers of the present invention can also be applied to treatment in a mixed culture system. The step of treating wastewater sometimes uses a microorganism-mixed culture system. In some cases, it is advantageous to adjust the proportion of the microbial mixture to a suitable ratio. Treatment efficiency can be improved as compared with treatment in the conventional mixed culture system, by culturing the magnetic carriers with different kinds of microorganisms immobilized thereon at a suitable ratio in chambers 1 and 2 respectively, and by intentionally controlling the particularly rate-determining treatment of microorganisms.
Further, for example, as shown in Example 9 below, a large amount of the magnetic carriers of the present invention can be adhered firmly to a permanent magnetic plate provided in an extrusion-type treatment chamber, thus permitting the microorganisms to be maintained at high density even if treated water is passed at considerably high rate, and thus treatment efficiency is improved.
The microorganisms-immobilized magnetic carriers of the present invention have a larger amount of microorganisms immobilized thereon. Further, movement of the carriers can be easily controlled by application of a magnetic field. Therefore, wastewater treatment can be conducted efficiently. In addition, according to the present invention, such microorganism-immobilized magnetic carriers can be easily produced.
EXAMPLES
The present invention is described below in more detail by the Examples, which however are not intended to limit the scope of the present invention.
Example 1
Production of Microorganisms-Immobilized Magnetic Carriers
12.5 g of acrylamide monomer, 0.6 g of N′,N″-ethylene-bis-acrylamide, 1 ml of N,N,N′,N′-tetraethylethylenediamine and 0.5 g of sodium alginate were dissolved in distilled water (final volume: 75 ml), and 1 to 3% (w/v) magnetite powder was suspended in the resulting solution, to prepare an aqueous solution (A).
On the other hand, sludge collected from a sewage disposal plant was sedimented by centrifugation such that it was concentrated to a volatile floating material content of about 1 to 3%, to give a microbial suspension (B).
The aqueous solution (A) was passed through the outer tube of a double-tubular nozzle (inner diameter of the outlet of the outer tube: 2.0 mm, the inner diameter of the outlet of the inner tube: 1.5 mm, the outer diameter of the outlet of the inner tube: 1.7 mm), while the suspension (B) was passed through the inner tube, so that the aqueous solution (A) and suspension (B) were instantaneously mixed at the top of the nozzle to form droplets. The aqueous solution (A) had previously been cooled to 4° C. The supplied suspension (B): aqueous solution (A) ratio in volume was controlled at a ratio of about 5:2.5 to 5:3 by using a roller pump. Droplets formed at the top of the double-tubular nozzle were then dropped into the aqueous solution (C) containing 3% calcium formate and 0.5% ammonium persulfate. The aqueous solution (C) had previously been cooled to 4° C. When the droplets were dropped into the aqueous solution (C), a film of calcium alginate was instantaneously formed to give granular beads. The beads were left in the aqueous solution (C) for 30 minutes to complete gelation by cross-linking reaction between the acrylamide monomer and the cross-linking agent such as N,N′-ethylene-bis-acrylamide etc., as well as entrapped immobilization of the ultra-paramagnetic body and microorganisms in the gel, in a mixture of the aqueous solution (A) and suspension (B) entrapped with a film of calcium alginate. The spherical bead-shaped microorganism-immobilized magnetic carriers with suitable strength, entrapped with a film of calcium alginate, were obtained in this manner.
The resulting magnetic carriers were washed with water and then immersed in 0.05 M potassium phosphate to elute calcium alginate from the surface layer in order to form more porous magnetic carriers. The spherical bead-shaped porous microorganism-immobilized magnetic carriers with an average particle diameter of about 3 mm were obtained in this manner.
Example 2
Production of Denitrificater-Immobilized PVA Magnetic Carriers for Elimination of N (Nitrate Nitrogen) from NO 3 −
Microorganism-immobilized magnetic carriers containing PVA gel in place of polyacrylamide gel and denitrificater as the microorganisms (referred to hereinafter as “denitrificater-immobilized PVA magnetic carriers”) were prepared in the following manner.
Magnetite powder was suspended in 12% PVA aqueous solution containing 0.8% sodium alginate so as to give a final concentration of 15 g/L magnetite powder in beads, whereby an aqueous solution (A) was prepared.
On the other hand, a denitrificater culture was concentrated by centrifugation to about 50 g/L (in dry base) to give a microbial suspension (B).
Formation of spherical beads using the double-tubular nozzle was conducted in the same manner as in Example 1. In this case, the supplied suspension (B): aqueous solution (A) ratio in volume was controlled by a roller pump, so that 15 g/L magnetite and 10 g/L (in dry base) denitrificater were contained in the beads. The spherical beads obtained by dropping droplets into the aqueous solution (C) were frozen at −20° C. and left as such for 24 hours. By this treatment, gelation by cross-linking reaction as well as entrapped immobilization of the ultra-paramagnetic body and denitrificater into the resulting gel were completed. The spherical bead-shaped denitrificater-immobilized PVA magnetic carriers with suitable strength, entrapped with a film of calcium alginate, were obtained in this manner.
The resulting magnetic carriers were washed with water and then immersed in 0.05 M potassium phosphate to elute calcium alginate from the surface layer in order to form more porous magnetic carriers. The spherical bead-shaped porous denitrificater-immobilized PVA magnetic carriers with an average particle diameter of about 3 mm were obtained in this manner.
Example 3
Utilization of Microorganism-Immobilized Magnetic Carriers in Batch Treatment
A wastewater suspension of the porous microorganisms-immobilized magnetic carriers 1 obtained in Example 1 was introduced into treatment chamber 2 (FIG. 1 A). Then, the magnetic carriers 1 were forcibly aggregated and sedimented by applying a magnetic field upward from magnet 3 placed below the treatment chamber 2 (FIG. 1 B). Then, the supernatant was drawn as treated water (FIG. 1 C).
The magnetic carriers 1 remaining in the treatment chamber 2 can be used in seeding for subsequent batch culture. Further, the amount of microorganisms retained in the magnetic carriers 1 is almost constant, thus, the inflow of wastewater and the amount of treated water drawn corresponding thereto can be set at a constant value.
Example 4
Utilization of Microorganism-Immobilized Magnetic Carriers in Fluidized Bed Treatment (1)
As shown in FIG. 2A, a wastewater suspension of the porous microorganisms-immobilized magnetic carriers 1 obtained in Example 1 was introduced into treatment chamber 2 provided therearound with four magnetic coils 4 . Subsequently, and a magnetic field was generated by sending electric current into two magnetic coils 4 in a lower part of the treatment chamber, whereby the magnetic carriers 1 were moved downward (FIG. 2 A). Then, a magnetic field was generated by sending electric current into two magnetic coils 4 in an upper part of the treatment chamber, whereby the magnetic carriers 1 were moved upward (FIG. 2 B). By repeating this operation intermittently, the magnetic carriers 1 were moved to form a fluidized bed.
Example 5
Utilization of Microorganism-Immobilized Magnetic Carriers in Fluidized Bed Treatment (2)
A wastewater suspension of the porous microorganisms-immobilized magnetic carriers 1 obtained in Example 1 was introduced into the treatment chamber 2 provided in the center with a metal core 5 and wound by magnetic coil 4 . Subsequently, a magnetic field was generated by sending electric current into magnetic coil 4 , whereby the magnetic carriers 1 were aggregated around the metal core 5 (FIG. 3 A). When the electric current was stopped, the magnetic carriers 1 were dispersed (FIG. 3 B). By repeating this operation intermittently, the magnetic carriers 1 were moved to form a fluidized bed.
Example 6
Utilization of Microorganism-Immobilized Magnetic Carriers in Fixed Bed Treatment
A wastewater suspension of the porous microorganisms-immobilized magnetic carriers 1 obtained in Example 1 was introduced to the treatment chamber 2 provided with magnetic coils 4 and 4 ′ on both sides. Subsequently, a magnetic field was generated by sending electric current into only the left magnetic coil 4 outside the treatment chamber 2 , whereby the magnetic carriers 1 became denser in the left in the treatment chamber 2 (FIG. 4 A). Then, the electric current into the left magnetic coil 4 was stopped, and a magnetic field was generated by sending electric current into the right magnetic coil 4 ′, whereby the magnetic carriers 1 became denser in the right in the treatment chamber 2 (FIG. 4 B). By switching the state from A to B and then B to A intermittently at few-second intervals, formation of a short-cut pathway of wastewater and clogging of the fixed bed can be prevented.
Example 7
Utilization of Microorganism-Immobilized Magnetic Carriers as Treatment-Improving Material or Seeding Material
The porous microorganisms-immobilized magnetic carriers 1 obtained in Example 1 were introduced into culture chamber 6 , and the microorganisms were cultured in the most suitable conditions for their growth. The magnetic carriers having a sufficient amount of the microorganisms immobilized thereon were stocked (FIG. 5 A). Then, strong electromagnet 7 was introduced into the culture chamber 6 to recover the magnetic carriers 1 (FIG. 5 B), and the recovered magnetic carries 1 were introduced to the treatment chamber 2 as treatment-improving material or seeding material (FIG. 5 C).
Example 8
Utilization of Microorganism-Immobilized Magnetic Carriers in Mixed Culture Type Treatment
Acid-producing bacterium-immobilized magnetic carriers 1 and methane-producing bacterium-immobilized carriers 1 ′ stocked according to the method of Example 7 were retained and cultured in treatment chambers 2 and 2 ′ respectively (FIG. 6 ). Because the growth rate of the methane-producing bacteria was considerably lower than that of the acid-producing bacteria, a larger amount of the methane-producing bacterium-immobilized carriers 1 was introduced to the treatment chamber 2 ′. An upward magnetic field was applied by sending electric current into the magnetic coil 4 over the treatment chambers 2 and 2 ′. Then, the electric current into the magnetic coil 4 was stopped, and a downward the direction magnetic field was applied by sending electric current into the magnetic coil 4 ′. By switching the direction of magnetic field at few-second intervals in this manner, a fluidized bed or fixed bed was formed in each chamber. The transfer of wastewater from treatment chamber 2 to treatment chamber 2 ′ was conducted by quantitative overflow via a notch provided in the upper part of partition plate 8 .
Example 9
Utilization of Magnetic Carriers in Extrusion-Type Treatment Chamber
FIG. 7 is an upper sectional view of treatment chamber 2 provided with a plurality of permanent magnets 9 . These magnets are corrugated to enlarge their surface area and also act as partition plates. By allowing a large amount of magnetic carriers 1 to adhere to the permanent magnets 9 with a broad surface area, and to be retained on them, the microorganisms can be kept at high concentration in the treatment chamber 2 . Wastewater is passed by extrusion through the treatment chamber in the direction of the arrow, during which it is treated by the microorganisms immobilized on the magnetic carriers 1 . Due to fixation by magnetic force, the magnetic carriers 1 are firmly retained, thus, even if wastewater is passed at considerably high speed, the carriers do not flow out.
Example 10
Removal of Nitrate Nitrogen by Batch Treatment Method Using Denitrificater-Immobilized Magnetic Carriers for Elimination of N in form of NO 3 − (Nitrate Nitrogen)
Porous denitrificater-immobilized magnetic carriers were produced in the same manner as in Example 1. The porous denitrificater-immobilized magnetic carriers were used to treat wastewater containing N (in NO 3 − ) at a concentration of 30 mg/L to examine a change with time in removal of nitrate nitrogen. As the comparative example, the denitrificater not immobilized on the carriers were used for treatment in the same manner to examine a change with time in removal of nitrate nitrogen. FIG. 8 shows the change with time in removal of nitrate nitrogen where the porous denitrificater-immobilized magnetic carriers and the non-immobilized denitrificater were used respectively. As can be seen in FIG. 8, the denitrificater-immobilized magnetic carriers of the present invention demonstrate about 4-times higher rate of removal of nitrate nitrogen than the non-immobilized denitrificater, indicating efficient treatment.
Example 11
Removal of Nitrate Nitrogen by Fixed-Bet Treatment Method Using Denitrificater-Immobilized Magnetic Carriers for Elimination of N in form of NO 3 − (Nitrate Nitrogen)
Porous denitrificater-immobilized magnetic carriers were produced in the same manner as in Example 1. The porous denitrificater-immobilized magnetic carriers were used to treat wastewater containing N (in NO 3 − ) at a concentration of 90 mg/L by a continuous treatment method to examine a change with time in removal of nitrate nitrogen. FIG. 9 shows the change with time in removal of nitrate nitrogen by the porous denitrificater-immobilized magnetic carriers. As can be seen in FIG. 9, the magnetic carriers of the present invention demonstrate a high removal effect at about 40 hours after the operation was initiated. The hydraulic average retention time in this continuous treatment method was 24 to 30 hours.
Example 12
Removal of Nitrate Nitrogen by Batch Treatment Method Using Denitrificater-Immobilized PVA Magnetic Carriers for Elimination of N in form of NO 3 − (Nitrate Nitrogen)
The porous denitrificater-immobilized PVA magnetic carriers obtained in Example 2 were used to treat wastewater containing N (in NO 3 − ) at a concentration of about 85 mg/L to examine a change with time in removal of nitrate nitrogen. Said treatment was conducted by introducing 200 ml of said wastewater and 20 g of said porous denitrificater-immobilized PVA magnetic carriers into a 300-ml Erlenmeyer flask and stirring the mixture with a stirrer at 200 rpm.
FIG. 10 shows the change with time in removal of nitrate nitrogen by the porous denitrificater-immobilized PVA magnetic carriers. As can be seen in FIG. 10, the porous denitrificater-immobilized PVA magnetic carriers demonstrate a high removal effect at about 40 to 50 hours after the operation was initiated.
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The present invention relates to magnetic carriers in which microorganisms requiring carriers for their growth in the step of treating wastewater have been immmobilized, a process for producing the carriers and a method of treating wastewater. The present invention provides microorganisms-immobilized carriers with a high amount of microorganisms immobilized for use in wastewater treatment, the movement of which is controllable in a treatment chamber by magnetic force. Further the present invention provides a process for producing said carriers easily and a method for treating wastewater efficiently.
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BACKGROUND OF THE INVENTION
This invention relates to an apparatus and method for mounting electronic components made by punching out the components bonded on film carriers to, for example, a liquid crystal display panel.
A display panel of liquid crystal is fabricated by connecting the leadwires of an electronic component to electrodes which are on the periphery of the display panel. The electronic components are made by stamping out the electronic components bonded on film carriers. This method is called TAB method (tape automated bonding method). FIGS. 8(a)-8(c) depict a conventional method for punching out electronic components.
In FIG. 8(a), there is shown an electronic component in the form of a chip 2 and leadwires (not shown) bonded on a film carrier 1 supplied from a supply reel (not shown). An upper die 3 has a punch 4, while a lower die 5 has a knock-out pin 6. A film carrier 1 is wound up by a take up reel (not shown) and progresses intermittently between the upper die 3 and the lower die 5. In FIG. 8(a) the film carrier 1 is stopped with the chip 2 between the punch 4 and the knock-out pin 6.
In FIG. 8(b), the upper die 3 is lowered to punch the film carrier 1. The knock-out pin 6 is pushed by the punch 4 and is lowered against an upward supporting force of a spring (not shown).
In FIG. 8(c), the upper die 3 is raised. The knock-out pin 6, with the punched electronic component 7 on it, is raised also by a mechanism (not shown). A removing device 8 with a take out nozzle 9 is inserted between the upper die 3 and the lower die 5 to suck up the electronic component 7.
As shown in FIG. 8(c), the upper die 3 has to move with long strokes in order to provide a clearance in which the take out nozzle 9 can be inserted. The distance of each of the strokes prolongs the fabrication time of the process by making the upper die 3 move in longer strokes than if the take out nozzle did not have to be inserted. Also, the movement of the upper die through these longer strokes magnifies the shock of the upper die 3 in punching the film carrier, thereby vibrating the stamping device 10. This vibration results in improperly positioning leadwires (not shown) of the punched out electronic components relative to the electrodes of a display panel of liquid crystal. Hence, the conventional process illustrated in FIGS. 8(a)-8(c) creates the problem of making it more difficult to connect the leadwires of the electronic components to the electrodes of, for example, a display panel of liquid crystal.
In addition, the conventional process can misalign the electronic component with respect to the take out nozzle, as shown in FIG. 9.
FIG. 9 shows the knock-out pin 6 raised with the punched electronic component 7 on top. As shown in the FIG. 9, burrs E1 and E2 often occur in opposite directions with each other at the edges of the film carrier 1 as the number of punchings or stampings increases. The interference between the extended burrs E1 and E2, when the knock-out pin 6 rises through a punched hole of the film carrier 1 as shown in FIG. 8(c) sometimes moves the electronic component 7 out of place, as shown with a broken line in FIG. 9. This position deviation interferes with the take out nozzle 9 to suck up the electronic component 7 at a proper position. Hence, the conventional process creates the additional problem of making it difficult to remove the electronic component once it has been stamped out.
The present invention, as described hereinafter, provides a mounting or fabricating device which solves the above problems created by the conventional process described above.
SUMMARY OF THE INVENTION
According to this invention, a mounting device is provided, which mounts electronic components, stamped out from film carriers, to a substrate. The mounting device of this invention comprises:
1. a supplying means of film carriers having electronic components on it,
2. a holding means for holding a substrate,
3. a punching means for punching out electronic components on the film carriers comprising:
a) an upper die,
b) a lower die having a through hole, wherein the upper die punches electronic components on the film carriers into the through hole,
4. a take out means for taking out the punched electronic components through a bottom of the through hole and for transmitting them to a transferring means,
5. a transfer means for transferring the electronic components transmitted with the take-out means to mounting positions adjacent said holding means, and
6. a pressure bonding means for pressure bonding leadwires of the electronic components to electrodes of a substrate.
In addition, according to the present invention, a process for mounting electronic components, stamped out from a film carrier, to a substrate is provided. The process comprises the following steps:
1. adjusting the position of a film carrier having electronic components thereon to a punching means,
2. punching out an electronic component bonded on the film carrier,
3. taking out the punched out electronic component through a bottom of said punching means and transmitting the electronic component to a transfer means by the take out means,
4. using the transfer means to transfer the transmitted electronic component to a mounting position, and
5. pressure bonding leadwires of the electronic component with electrodes of the substrate at said mounting position.
As pointed out in greater detail below, taking out the punched out electronic components through the bottom of a punching means rather than from a space between the upper and lower die of a punching means provides important advantages. For example, the electronic components will be in the proper position when being removed for transfer to the mounting position. In addition, the punching means uses shorter strokes since the electronic component take out means does not have to be inserted in between upper and lower dies. As a result, the punching means of this invention uses shorter strokes than the conventional dies and causes less vibration. Hence, the present invention provides an important benefit of properly aligning or positioning the leadwires of the punched out electronic components with the electrodes of the substrate to which the leadwires are being connected.
The invention itself, together with further objects and attendant advantages, will best be understood by reference to the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of a punching, take out and mounting device according to the first embodiment of this invention.
FIG. 2 is a side view of the first embodiment shown in FIG. 1.
FIG. 3 shows a plurality of boards for feeding carrier films to a punching device according to this invention.
FIGS. 4(a)-4(c) show side views of the punching and take out devices according to the invention.
FIG. 5 shows a control system for the mounting device of this invention.
FIG. 6 is a top view of a punching and take out device according to a second embodiment of this invention.
FIG. 7 is a top view of a punching and take out device according to a third embodiment of this invention.
FIGS. 8(a)-8(c) show a conventional punching and take out device.
FIG. 9 shows the problems with a conventional punching and take out device.
DETAILED DESCRIPTION OF THE INVENTION
First Embodiment
FIGS. 1-4 show a mounting or fabricating device according to a first embodiment of this invention.
First, the structure for punching out and taking out or removing the electronic components is explained.
In FIG. 1, the take out means 11 has a plurality of arms 12. As shown in FIGS. 2 and 3, the take out means is fixed to a shaft 14a, and each arm 12 has a take out nozzle 13 on each tip. The take out means 11 is driven by an index driver 14 and rotates together with the shaft 14a. The index driver 14 is placed on X-table 15 and Y-table 16. The tables, X-table 15 and Y-table 16, are mounted on a base 20. Motors, identified as X-table motor 17 and Y-table motor 18, drive the X-table in the X direction and Y-table in the Y direction, respectively. Thus, the location of the take out means 11 is adjustable by moving the X-table 15 and the Y-table
FIG. 4(a) shows the punching means 40 and a tip of the arm 12. A lower die 42 has a through hole 43. An upper die 49 has a guide rod 46, which guides the up and down movement of the upper die 49. The upper die 49 has a punch 50, and is coupled to a rod 48 of a cylinder 47. A cylinder 22 is fixed to the tip of the arm 12. At the tip of said cylinder 22 is a nozzle shaft 21, which is driven by the cylinder 22 to move the shaft 21 up and down. The take out nozzle 13 is mounted on the nozzle shaft 21 with a sucking side face up. The broken line shows an upper specific position of the take out nozzle 13 and the solid line shows a lower specific position.
As shown in FIG. 4(b), the upper die 49 punches a film carrier 1A to stamp out an electronic component 7 by means of the downward movement of the rod 48. The take out nozzle 13 sucks up the stamped out electronic component 7 at the upper specific position.
As shown in FIG. 4(c), the upper die 49 is returned upward by means of the upward movement of the rod 48. The take out nozzle 13, which sucked the electronic component 7, goes down to the lower specific position.
Thus, the stamped out electronic component 7 is taken out through the bottom of the through hole 43 of the lower die 42. After the component is taken out, the arm 12 rotates to move the take out nozzle 13 (out of FIG. 4) and transmit the stamped out electronic component 7 to a transferring nozzle (explained hereinafter).
An electric motor 23 rotates the nozzle shaft 21 via pulleys 24 and 25 and a belt 26 in order to adjust an angular position of the electronic component 7 sucked up by the take out nozzle 13.
Turning back to FIG. 1, the description of the process of punching out a plurality of electronic components follows. Film carriers 1A, 1B and 1C having sprocket holes on both edges, are fed to the tip of each arm 12 of the take out means 11. Electronic components 2A, 2B and 2C, bonded on the film carriers 1A, 1B and 1C, respectively, are stamped out by a punching means 40, as described with respect to FIGS. 4(a)-4(c), along a punch-guide-line 19. A punching means 40 is provided for each film carrier. The electronic components 2A, 2B, 2C may be identical ones or different ones.
Next, the structure for feeding the film carriers to the punching means is explained.
FIG. 2 shows a board 31A having a film carrier 1A being supplied to the punching means 40 via a supply reel 32, a guide roller 34 and a pair of sprockets 37. The sprockets 37 are engaged with the sprocket holes on the film carrier 1A to feed the film carrier 1A intermittently to the punching means 40. At the same time, the sprocket 37 controls the amount of film carrier 1A supplied to the punching means in order to locate or position the film carrier 1A properly, relative to the punching means 40. A reel 33 takes up a separate tape backing from the film carriers, while a reel 35 takes up the film carrier after the punching of an electronic component is completed. Each reel is driven by a driving device not shown in FIG. 2. In FIG. 3, boards 31B and 31C, having the same structure as the board 31A, feed film carriers 1B and 1C to respective punching means 40.
Next, the structure, for transferring the electronic components from the take out nozzle 13 and connecting the leadwires of an electronic component and the electrodes of a substrate, is explained.
The top view of a transfer means 51 is shown in FIG. 1.
As shown in FIG. 1, transfer nozzles 54 are provided on the tip of each arm 52 of the transfer means 51. The transfer nozzles 54 are driven by a built-in driving means (not shown) and move up and down.
Next, as shown in FIG. 2, the transfer means 51 is fixed on a shaft 53a. The transfer nozzle 54 is driven by an index driver 53 to rotate together with the shaft 53a. The movement of the transfer nozzle 54 is mainly an intermittent rotation by an angle of 90°. An intersection is found between a locus of the take out nozzle 13 and a locus of the transfer nozzle 54. As shown in FIG. 2, at this intersection (hereinafter called the transfer point), the take out nozzle 13 and the transfer nozzle 54 overlap each other, and the electronic component 7 is transferred from the take out nozzle 13 to the transfer nozzle 54. To be more specific, the take out nozzle 13 loses its sucking power due to being cut off from a vacuum source, while the transfer nozzle 54 is coupled to the vacuum source and gains sucking power. As a result, the electronic component 7 is sucked by the transfer nozzle 54 away from the take out nozzle 13. In FIGS. 1 and 2, the transferred electronic component 7 is shifted or rotated from the transfer point to a place above a mounting point 180° away from the transfer point to a mounting point. The transfer nozzle 54 is lowered as the electronic component 7 arrives at the mounting point. At the mounting point, the leadwires (not shown) of the electronic component 7 are placed over the electrodes of a substrate such as, for example, a liquid crystal display panel 60. The leadwires and electrodes are separated by an anisotropic conductive film between them, which film is stuck on the electrodes for connecting the electrodes to the leadwires. These two elements are pressure bonded through pressure and heat provided by a thermal bonding head 71.
As shown in FIGS. 1 and 2, each electronic component 7 is mounted on the periphery of the liquid crystal display panel 60 placed on a movable table 61. The movable table 61 can adjust the position of a substrate such as the display panel 60 in the directions of X, Y and O (rotation). The thermal bonding head 71, which pressure bonds the leadwires of electronic component 7 with the electrodes of the display panel 60 is mounted at the tip of a bonding means 70. During the thermal pressure bonding, a supporting material 73, supported by the cylinder 72, supports the bottom of display panel 60. On the other hand, a supporting material 75 on the rod 74 is used to support a lower face of the electronic component 7 at the mounting point. A monitor camera 55 (FIG. 1) detects the position of electronic component 7 sucked to the transfer nozzle 54. According to the position detected by the camera, the movable table 61 can make a rough adjustment of the position of display panel 60. Another camera 77 detects any misalignments between the leadwires of electronic component 7 and the electrodes of the display panel 60. According to the results of the detection by camera 77, the movable table 61 can make a fine adjustment of the position of the display panel 60, so that the leadwires of the electronic component 7 can be exactly mounted relative to the electrodes of the panel.
Next, the control system, as illustrated in FIG. 5, is described.
The sucking action on an electronic component as well as the releasing of the component by the take out nozzle 13 and the transfer nozzle 54 is controlled through the opening and shutting of the vacuum source 80 by a valve 13a and a valve 54a. The driving of the cylinder 22, which drives the take out nozzle 13 up and down, is controlled through the opening and shutting of a high-pressured-air source 90. A double-acting cylinder 47, which drives the punch 50 of a punching device, is controlled by switching the air-supply-direction of the high-pressured-air source 90 by a valve 47a. A valve control circuit 91 controls the valves 13a, 54a, 22a and 47a independently with commands from a central processing unit (CPU) 98.
An electric motor drive-circuit 23a controls an electric motor 23, which adjusts the angular position of the take out nozzle 13. An electric motor drive-circuit 38a controls an electric motor 38, which drives the sprocket 37. An index drive-circuit 92 controls an index driver 14. A pressure bonding means drive-circuit 93 controls a press-fit means 70. A transfer means control-circuit 94 controls a transfer means 51. A movable table control-circuit 95 controls the movable table 61. All these control circuits receive commands from the CPU 98 through an interface 83. Recognition circuits 96 and 97 feed the position information, detected through the monitor cameras 55 and 77 about the electronic component 7 sucked to the transfer nozzle 54, and positioned on the table 61 to the CPU 98. The CPU 98 controls the entire device according to a program and data stored in the memory 99.
Next, the entire process of the present invention is explained by describing the steps from feeding and punching out an electronic component from a film carrier to the mounting of the electronic component to a substrate, such as a display panel of liquid crystal. These steps are as follows:
STEP 1: A selected take out nozzle 13, which does not have the electronic component 7, is placed at a lower specific position.
STEP 2: A film carrier is fed or inserted between the punch 50 and the lower die 42, driven by the sprocket 37. The position of a film carrier is preadjusted so that the electronic component 7 being stamped out is positioned just above the through hole 43.
STEP 3: The take out nozzle 13 rises to the upper specific position.
STEP 4: The valve 13a is opened to provide the take out nozzle 13 with a vacuum to permit the nozzle to suck out the component.
STEP 5: The punch 50 is lowered and the electronic component 7 is stamped out from the film carrier. The electronic component 7, after being stamped out, is sucked to the take out nozzle 13.
STEP 6: The punch 50 is raised.
STEP 7: The take out nozzle 13, which is still sucking the electronic component 7 is lowered to the lower specific position.
STEP 8: The take out means 11 is rotated and the take out nozzle 13, which is still sucking the electronic component 7, is moved to the transfer point.
STEP 9: The transfer means 51 is rotated and the transfer nozzle 54, which is commanded to receive the electronic component 7, is moved to the transfer point.
STEP 10: At the transfer point, the lowered transfer nozzle 54 is moved close to the electronic component 7. The valve 54a is opened to provide the transfer nozzle 54 with a vacuum to permit the nozzle 54 to suck up the component.
STEP 11: The valve 13a is shut off, causing the take out nozzle 13 to lose its vacuum sucking power. As a result, the electronic component 7 is transferred from the take out nozzle 13 to the transfer nozzle 54.
STEP 12: The transfer nozzle 54, which is sucking the electronic component 7, is raised.
STEP 13: A transfer means 51 is rotated and the transfer nozzle 54, which is still sucking the electronic component 7, is moved toward the mounting point.
STEP 14: The camera 55 detects the position of the electronic component 7 sucked to the transfer nozzle 54.
STEP 15: The movable table 61 makes a rough adjustment of the display panel 60 according to the position detected by the camera 55 in STEP 14.
STEP 16: The transfer nozzle 54, which is still sucking the electronic component 7, is positioned above the mounting point.
STEP 17: The camera 77 detects the positional difference between leadwires of the electronic component 7 and electrodes of the display panel 60.
STEP 18: The movable table 61 makes a fine positioning adjustment of the display panel 60, so that the above positional difference may become zero.
STEP 19: The transfer nozzle 54 which is still sucking the electronic component 7, is lowered to position the electronic component 7 at the mounting point.
STEP 20: A thermal bonding head 71 is lowered to bond the leadwires of the electronic component 7 with the electrodes of the liquid crystal display panel by thermal pressure bonding.
STEP 21: After the thermal compression, the valve 54 is shut off causing the transfer nozzle 54 to lose its vacuum sucking power.
STEP 22: The transfer nozzle 54 is raised.
STEP 23: The movable table 61 is moved to position a display panel for the mounting of the next electronic component at the mounting point.
Second Embodiment
FIG. 6 shows a second embodiment of this invention. A take out means 11 having an arm 12 is placed on a table 16 movable in the Y-direction. The arm 12 is rotatable, as well as movable along the Y direction. A guiding means 16a guides the movement of the take out means 11. Two punching devices 40 are placed at each side of the Y-table 16. Specifically, a total of four punching devices are used. Film carriers 1A, 1B, 1C and 1D are fed to respective punching devices 40. The take out nozzle 13 selects a film carrier by rotation and movement along the Y direction, and takes out the electronic component 7 through the bottom of the through hole of the lower die of the punching device 40. The remaining steps in the process are the same as those described under the first embodiment.
Third Embodiment
FIG. 7 shows a third embodiment of this invention. A take out means 11 has an arm 12 that is only rotatable. A punching device 40 is placed at each side of the take out means. Film carriers 1A and 1B are fed respectively, to each punching device 40. The take out nozzle 13 selects a film carrier by rotation, and takes out an electronic component 7 through the bottom of the through hole of the lower die of the punching device. 40. The remaining steps in the process are the same as described under the first embodiment.
Advantages
As explained above, the take out means of this invention takes out an electronic component through the bottom through hole of the lower die. This method offers the following advantages over the conventional process of stamping out components and pushing them up to a take out nozzle placed between a pair of dies, which dies have to be spaced sufficiently enough apart to accept the take out nozzle:
1. The interference between burrs E1 and E2 that occurred by the conventional process described above does not occur in the present invention, since the punched electronic component is not raised through the punched hole of the film carrier. As a result, the take out nozzle of the present invention sucks an electronic component from a proper position since the likelihood that an electronic component may be moved from its proper position is reduced.
2. The take out nozzle of the present invention is not inserted between the upper and lower dies, and hence, the punching device of the present invention uses shorter strokes than the conventional punch. As a result, vibration of the mounting device is reduced and the leadwires of the electronic component are more likely to remain properly aligned to achieve a high precision in connecting the leadwires of an electronic component to the electrodes of a substrate.
3. The shorter strokes taken by the punching device of the present invention shorten the fabrication time of the process.
4. Since the punching device of the present invention neither has knock-out pins nor a machine in which knock-out pins move up and down, the punching device can be of a smaller size than the conventional device.
5. Also the use of a plurality of punching devices according to the present invention reduces wasted time in the process, since immediately after the electronic components are punched from a film carrier, another punching device can punch out electronic components from another film carrier and feed the electronic components to have their leadwires bonded. The present invention has the advantage of providing a continuous process.
Of course, it should be understood that a wide range of changes and modifications can be made to the preferred embodiment described above. It is therefore intended that the foregoing detailed description be understood that it is the following claims, including all equivalents, which are intended to define the scope of this invention.
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In an apparatus for mounting electronic components, punched out from film carriers to a substrate, there is disclosed an upper die for punching the electronic components through a hole formed in a lower die. A take out nozzle is located under the through hole for sucking the punched out electronic component from the hole in the lower die. A transfer nozzle is provided for receiving the electronic component from the take out nozzle and for transmitting the electronic component to a substrate mounted on a movable table. Before any leadwires of the component are bonded to the electrodes of the substrate, the table is finely positioned to property align the leadwires and the electrodes.
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CLAIM OF PRIORITY
Applicants hereby claim the priority benefits under the provisions of 35 U.S.C. §119, basing said claim of priority on German Patent Application Serial No. 10 2009 025430.7, filed Jun. 16, 2009. In accordance with the provisions of 35 U.S.C. §119 and Rule 55(b), a certified copy of the above-listed German patent application will be filed before grant of a patent.
BACKGROUND OF THE INVENTION
The invention relates to a motor vehicle having an electric drive, and an electric energy storage module therefor.
Motor vehicles that are powered or driven, at least in part, with electrical energy (so-called hybrid drives) are among the prior art. The electrical energy for the electric drive is carried in storage modules that are also called battery packets. The weight of these storage modules is significant, particularly in motor vehicles that are driven exclusively by electricity. It is not uncommon for the storage modules to weigh 300 to 500 kg in order to attain a corresponding driving range. One problem associated with these large battery packets is their integration into existing vehicle concepts, i.e. adapting them to the so-called vehicle packaging. Another problem is the relatively long charging times required for the storage modules. Although the charging times are constantly being optimized and therefore further reduced, at low charge currents, it typically takes several hours to fully charge the storage modules. Alternatively, the empty storage modules can be exchanged for fully charged storage modules. Naturally, exchanging the storage modules must be quick and simple.
SUMMARY OF THE INVENTION
One object of the present invention is to provide a motor vehicle having an electric drive in which exchanging storage modules is simple and quick, and in which the storage modules can also be secured or attached with good crash resistance.
This object is attained in a motor vehicle having the features of patent claim 1 .
The subordinate claims relate to advantageous refinements of the inventive thought.
In the present inventive motor vehicle, the storage module or modules are supported and/or arranged in a guide that extends longitudinally along the motor vehicle. The storage modules are longitudinally displaceable relative to the guide. This construction simplifies the loading of the storage modules into the motor vehicle. Naturally, it also simplifies removing the storage modules from the motor vehicle. In addition, an impact damping unit may also be arranged at one or both ends of the guide. The present invention takes into consideration that the storage modules are relatively heavy, and consequently may move within the longitudinally extending guides in the motor vehicle during a crash. The storage modules should be retained in place by impact damping units arranged at each end of the guide in order to prevent the storage modules from being damaged themselves, or even shifting longitudinally out of the guide during an abrupt deceleration. The crash or impact energy imparted to the storage modules is dissipated and converted to a different energy. In particular, the crash energy is absorbed by the impact damping unit through deformation.
Moreover, the arrangement of the guide in the longitudinal direction of the motor vehicle has the advantage that the weight of the storage module is distributed onto both the front axle and the rear axle of the motor vehicle. The guide preferably extends from the front axle to the rear axle of the motor vehicle. The guide can be configured in the form of a channel that connects the front and rear axles of the vehicle to one another. Positioning the storage module, and/or the guide, in the laterally center portion of the motor vehicle is also advantageous.
An impact damping unit is preferably provided, at least in the front area of the motor vehicle. In one advantageous refinement of the invention, the impact damping unit extends to a front bumper portion of the motor vehicle. This makes it possible to distribute the weight of the storage module across nearly the entire length of the motor vehicle. It is also possible to position the impact damping unit directly in the guide. In this case, no additional space outside of the guide is needed for the impact damping unit. The impact damping unit can be supported on a retention plate attached at one end of the guide.
The storage module typically comprises a plurality of individual storage elements. Disposed therein are individual battery or accumulator cells with associated electronic units. For safety reasons, the voltage is limited e.g. to 60 volts direct current for each storage element.
In a practical embodiment of the present invention, the guide preferably has an upwardly opening, C-shaped cross-sectional configuration. Thus, the guide has a base on the bottom, upward-facing legs connected longitudinally to each side of the base, and bars connected to the legs that face one another and define open guide grooves. Such a guide, which can also be called a rail, secures the storage elements or a storage module held therein very securely against laterally acting forces. The C-shaped configuration also protects the individual storage elements against vertical displacement. The individual storage elements are, at least in part, laterally enclosed, and therefore positively connected with the guide. The only freedom of movement of the storage module is longitudinal displacement along the guide. The storage module preferably includes seating units that are arranged in a longitudinally displaceable fashion in the guide. The storage elements fit into the seating units. In other words, the storage elements are not held directly by the guide, but rather are mechanically connected to seating units which are in turn supported in the C-shaped guide.
The seating units orient the storage elements in the same manner and orientation as the guide groove retains the seating units. More specifically, the seating units grip lateral retention bars on the storage elements. What is important is that all of the storage elements can be displaced only in the longitudinal direction of the guide. The seating units and the storage elements thus have a positive interconnection using fitting elements that are configured to fit with one another, such as using a groove and spring arrangement.
The seating unit may theoretically be longer than the storage elements when the same are arranged in a row. The number of storage elements may be coordinated with the associated vehicle type.
The present invention makes it possible to attach or mount a standardized storage module in a vehicle very rigidly. The storage elements are combined to create an elongate storage module that can be placed in a centrally disposed channel in the motor vehicle in a manner that conserves a good deal of space. The channel may extend between and interconnect the front axle to the rear axle of the vehicle. This connection has a positive effect on strength, and thus the behavior of the chassis. Because of the freedom in the selection of the material for the guide, it is possible to produce the guide from lightweight metals, especially aluminum, plastic, or composite materials, regardless of the materials used in other components of the motor vehicle. This design minimizes weight, while retaining substantial strength. Naturally, the freedom in the selection of the material can also reduce costs. The assembly and exchange of the storage module and storage elements is simple and inexpensive, while simultaneously providing excellent results in side crashes. The “resilient” or non-static support of the storage module is achieved by integrating in the support a crush box or impact damping unit. In a crash, the crush box makes it possible to absorb the associated kinematic energy, so as to avoid the need for the other party involved in the crash to absorb this impact energy.
These and other advantages of the invention will be further understood and appreciated by those skilled in the art by reference to the following written specification, claims, and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention shall be explained in greater detail in the following using the exemplary embodiment depicted schematically in the drawings.
FIG. 1 depicts the chassis of a motor vehicle having a guide that extends in the longitudinal direction of the motor vehicle;
FIG. 2 is a perspective elevation of the guide in FIG. 1 ;
FIG. 3 depicts a section through the guide depicted in FIG. 2 ; and,
FIG. 4 depicts an alternative to the motor vehicle in FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented in FIG. 1 . However, it is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.
FIG. 1 is a highly simplified schematic depiction of the chassis portion of a motor vehicle 1 . It can be seen that a guide 4 is disposed in the center of the motor vehicle 1 , and extends longitudinally along the motor vehicle 1 between a front axle 2 and a rear axle 3 . The guide 4 is depicted in detail in FIGS. 2 and 3 . The illustrated guide 4 connects the schematically depicted front axle 2 with the rear axle 3 . An impact damping unit 6 , also known as a crush box, is disposed on the front end 5 of the guide 4 . This impact damping unit 6 extends to a front bumper 7 that is also connected via crush boxes 8 to the body of the motor vehicle 1 .
The guide 4 receives and supports individual storage elements 9 . In this exemplary embodiment, the storage elements 9 are configured as rectangular units, and are placed into the guide 4 from the rear of the motor vehicle 1 . All together, the storage elements 9 and lateral seating units 15 , 16 form a storage module 19 ( FIGS. 2 and 3 ). The guide 4 is a component of a channel 10 , wherein the guide 4 defines the lower portion of the channel 10 , as can be seen in FIG. 2 . The guide 4 is configured open on top and with a C-shaped cross-section. The guide 4 includes a base 11 that defines or forms the bottom of the channel 10 . Legs 12 , that extend upwardly in the plane of FIG. 3 , are attached longitudinally to each side of the base 11 . Bars 13 are located on the upper portions of the legs 12 and face one another, so as to form or define mutually opposing undercut guide grooves 14 along the longitudinal portions of the base 11 . A longitudinally displaceable seating unit 15 , 16 for the storage module 19 is disposed in each of the guide grooves 14 . These seating units 15 , 16 are retained in and held by the guide grooves 14 , and have a generally U-shaped cross-sectional shape. Seating units 15 , 16 grip longitudinally protruding retention bars 17 , 18 on the storage elements 9 . Retaining elements 20 , in the form of bolts or the like, mechanically join the individual storage elements 9 to the seating units 15 , 16 . In this exemplary embodiment, one retaining element 20 is provided on each side of each storage element 9 , with the retaining elements 20 being arranged opposite one another.
The guide 4 , and/or the seating units 15 , 16 , may have an extruded construction. The longitudinal extension of the seating units 15 , 16 in the guide 4 is longer than a single storage element 9 . The seating units 15 , 16 act to some extent as an adapter between the storage elements 9 and the guide 4 . Consequently, it is possible to use the same guide 4 for storage elements 9 that have differently shaped retention bars or other connectors, simply by using alternatively configured seating units 15 , 16 in the inventive motor vehicle.
FIG. 4 depicts a modification to the embodiment in FIG. 1 . The impact damping unit 6 is arranged immediately at the end 5 of the guide 4 , and more specifically, within the guide 4 . Thus, it is shorter than the construction shown in FIG. 1 , and does not extend to the bumper 7 . A support plate 21 at the end of the guide 4 acts as a counterbearing that supports the impact damping unit 6 .
In the foregoing description, it will be readily appreciated by those skilled in the art that modifications may be made to the invention without departing from the concepts disclosed herein. Such modifications are to be considered as included in the following claims, unless these claims by their language expressly state otherwise.
Legend:
1 —Motor vehicle
2 —Front axle
3 —Rear axle
4 —Guide
5 —End
6 —Impact damping unit
7 —Bumper
8 —Crush box
9 —Storage element
10 —Channel
11 —Base
12 —Leg
13 —Bar
14 —Guide groove
15 —Seating unit
16 —Seating unit
17 —Retention bar
18 —Retention bar
19 —Storage module
20 —Retention element
21 —Support plate
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A motor vehicle has an electric drive and at least one electrical energy storage module connected therewith. A guide extends longitudinally along the motor vehicle, and supports the storage module therein in a longitudinally displaceable manner relative to the motor vehicle.
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RELATED APPLICATIONS
This application is a continuation of U.S. Ser. No. 09/761,867, filed on Jan. 16, 2001, now abandoned which is a continuation of U.S. Ser. No. 09/567,694, filed May 9, 2000, now abandoned which claims priority from U.S. Ser. No. 60/134,970, filed May 20, 1999, and from U.S. Ser. No. 60/156,922, filed Sep. 28, 1999, each of which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates generally to simplified methods and apparatus for enabling users of computers coupled to the internet to access e-commerce web sites and to purchase goods and services from the web sites. In addition, the present invention is directed to methods of conducting business over computer networks including the Internet.
BACKGROUND OF THE INVENTION
Although the use of the Internet has grown considerably in the last few years, there is still a large percentage of the population that does not use the Internet on a regular basis, if at all. It is believed that many of these non-users of the Internet, would begin using the Internet if access to Internet sites was simplified. There are also many users of the Internet who are hesitant to purchase goods over the Internet because of concerns of credit card security and because of the time required to complete electronic order forms. Accordingly, there is a need for simplified methods and apparatus for accessing Internet web sites and purchasing goods and services from these web sites.
Businesses that sell goods and services over the Internet (sometimes referred to as e-tailors) typically spend significant resources on advertising trying to attract Internet users having certain demographic profiles to their web sites. Thus, there is also a need for developing simplified and economical methods and apparatus for targeting Internet users with specific interests and directing these users to e-commerce web sites offering goods and services related to these interests.
SUMMARY OF THE INVENTION
In accordance with principles of the present invention, a system for providing access to a computer network comprises a first computer operatively coupled to the computer network and a second computer operatively coupled to the computer network. A peripheral device, which is coupled to the first computer, includes a plurality of buttons. If one of the plurality of buttons is activated, the first computer responds by communicating a signal to the second computer over the computer network. The second computer is constructed and arranged to respond to the signal communicated from the first computer by redirecting the signal to a third computer to establish a network connection between the first computer and the third computer over the computer network.
In an embodiment of the present invention, the peripheral device is defined as a mouse pad. The mouse pad includes an electronics housing, an upper surface, a template and a cable for coupling to the first computer system. The upper surface of the mouse pad includes a planar pad area across which a mouse can slide to move a cursor on a computer screen. The mouse pad further includes a slot for receiving a removable template. The slot extends between an upper sheet and a lower housing of the mouse pad. The lower housing has an upper surface containing a plurality of membrane switches that may be actuated through the upper sheet and the template to generate a plurality of different signals corresponding to a plurality of different functions. The upper surface can include identification labels which are associated with each of the membrane switches. The identification labels are viewable through the upper sheet when the template is removed. The membrane switches are implemented such that the switches are not activated by movement of the mouse across the pad area. However, the membrane switches can be activated when sufficient tactile force is exerted thereon.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention, reference is made to the drawings which are incorporated herein by reference and in which:
FIG. 1 is a block diagram of a system in accordance with the present invention for accessing the internet;
FIG. 2 is a top view of an internet access peripheral incorporated into a mouse pad in accordance with one embodiment of the present invention;
FIG. 3 is a top view of a template used in the internet access peripheral of FIG. 2 ;
FIG. 4 is a front view of the internet access peripheral of FIG. 2 with the template of FIG. 3 removed from the internet access device;
FIG. 5 is a block diagram of the electronics contained within the internet access peripheral of FIG. 2 ;
FIG. 6 is a functional block diagram of a minibrowser software application used in one embodiment of the present invention;
FIG. 7 is a flow chart of the initial operation of the minibrowser software application of FIG. 6 ;
FIGS. 8-11 show screen displays generated by the minibrowser software application of FIG. 6 on the screen of the computer system of FIG. 1 ; and
FIG. 12 is a flowchart of a method of using an Internet access system of the present invention.
DETAILED DESCRIPTION
Embodiments of the present invention described below are directed to methods and apparatus for providing simplified access to the Internet, and for providing improved management of a user's Internet experience. However, the present invention is not limited for use with the Internet and may be used with intranet applications and other computer networks as well.
FIG. 1 shows a system 100 in accordance with one embodiment of the present invention. The system 100 includes a computer system 110 having a monitor 112 , a CPU housing 114 , a keyboard 116 , a mouse 118 and a mouse pad 120 . As shown in FIG. 1 , the computer system may be coupled to the Internet through an Internet service provider (ISP) using one of a number of known Internet browser applications. The system 100 also includes web servers 122 , 124 and 125 that are also coupled to the Internet and accessible by the computer system 110 over the internet. The system shown in FIG. 1 includes only one computer system for simplicity, however, as readily understood by those skilled in the art, the system may include a number of computer systems each having its own mouse pad and capable of communicating with the web servers.
Web server 122 is identified as the mouse pad server or simply the pad server and is programmed to support internet access features of the computer system 110 and the mouse pad 120 that are described below in further detail. Web servers 124 and 125 represent typical web servers that host e-commerce web sites. As understood by those skilled in the art numerous other web servers are coupled to the internet and may be accessed by the computer system 110 .
In one embodiment of the present invention, the computer system 110 includes a personal computer utilizing the Microsoft® Windows 98 operating system, an internet browser, such as Microsoft® Internet Explorer version 4.0 or Netscape Navigator version 4.0, and the computer system further includes a Pentium class microprocessor, at least 32 megabytes of RAM and an internet service provider (“ISP”). The ISP can be Mysmart.isp service provided by Mysmart.com of Los Angeles, Calif. or America On-line internet service provided by America On-line of Dulles, Va.
The mouse pad 120 is shown in greater detail in FIG. 2 . The mouse pad has an electronics housing 121 , an upper surface 127 , a template 140 and a cable 132 for coupling to the computer system 110 . In one embodiment, the cable is configured to mate with a universal serial bus (USB) port of the CPU housing 114 . The upper surface 127 has a pad area 129 across which the mouse 118 is moved to move a cursor on the computer screen.
FIG. 3 shows a top view of the template 140 removed from the mouse pad 120 , and FIG. 4 shows a front view of the mouse pad 120 with the template removed. The mouse pad includes a slot 142 for receiving the template. The slot extends between an upper sheet 144 and a lower housing 146 of the mouse pad. In one embodiment, the upper sheet is formed from a mylar sheet having an upper surface that forms the pad area 129 . The lower housing 146 has an upper surface 148 containing twenty membrane switches that may be actuated through the upper sheet and the template 140 to perform different functions as described below. In one embodiment, the upper surface also includes identification labels for each of the membrane switches. The identification labels are viewable through the upper sheet when the template is removed. The membrane switches are implemented such that the switches are not activated by movement of the mouse 118 across the pad area 129 , but may be activated when sufficient tactile force is provided by a user using, for example, one of the user's fingers. This is accomplished by using snap domes between a membrane of plastic sheets to buffer the area not utilized by the snap domes.
The template 140 is implemented in one embodiment of the present invention using a polymer sheet. In other embodiments, the template may be implemented using stiff paper, or cardboard, or any other material that is sufficiently flexible to allow activation of the membrane switches by a user's finger through the upper sheet and the template. In embodiments of the present invention, the upper surface of the template includes a brand area 150 that may contain printed material to identify the particular template, and in addition, the template may include specific identifiers or labels 126 a - 126 t for each of the membrane switches. For example, in a particular template, the brand area may include a label identifying the template as “Xbrand Shopping Mall,” and each of the labels may identify a different e-commerce web site that is accessed when the switch corresponding to the label is actuated. In another example, the template may be designated as “Sports” and some or all of the labels may identify a different sports related web site.
The template 140 has a unique code embedded in the template that allows the template to be identified by the mouse pad 120 . In the embodiment shown in FIG. 3 , the code is a 10 bit code implemented as a pattern 154 of indentations in the upper left corner of the template. When the template is inserted into the mouse pad, the upper left corner of the template extends into the electronics housing and contacts a 10 bit switch that reads the code on the template based on the pattern of indentations on the template. In other embodiments of the present invention, the code and code reader may be implemented using one or more of a number of known technologies such as bar codes, magnetic strips or smart chips. The template 140 also has a raised lip 156 to allow a user to easily insert the template into and remove the template from the mouse pad 120 .
The electronics housing 121 is secured to the top left corner of the mouse pad and contains electronics for providing the interface between the computer system and the mouse pad, for monitoring activation of the membrane switches, and for identifying the template. In addition, the electronics housing includes a smart card interface device having a slot for receiving a smart card 130 .
In the embodiment shown, the electronics housing has two status lights 123 that are implemented using light emitting diodes. One of the status lights is a power on button that indicates that power is being supplied to the mouse pad from the computer system. The other status light indicates a secure mode of operation. This other status light can be remain on during a secure mode of operation and can be controlled to flash if operation of the mouse pad is unsecured. A secure mode of operation can be established after the smart car 130 , which is positioned in the slot defined on the electronics housing, is validated. Smart card 130 validation can be based on reading and validating a personal identifier, which can be stored on the smart card 130 . The personal identifier can be associated with a predetermined user of the smart card 130 .
FIG. 5 provides a functional block diagram of the electronics design of the mouse pad 120 for one embodiment of the present invention. The major electrical components of the mouse pad include a controller 160 , a template detector 162 and the smart card interface device 164 , in addition to the membrane switches on the top surface of the pad. The switches are electrically configured in an 8×3 matrix indicated as the key matrix 166 in FIG. 5 (a total of 24 switches may be accommodated in the matrix, although in some embodiments, less than twenty switches may be used). In addition to the connections shown in FIG. 5 , the controller is also coupled to the status lights 123 .
In one embodiment, the controller 160 is implemented using a USB Human Interface Device (HID) compatible controller, such as the Cypress Cy7C63100A available from Cypress Semiconductor Corporation of San Jose, Calif. The controller interacts with the key matrix to detect activation of one of the switches, interacts with the smart card interface circuit 164 to receive data from the smart card interface circuit, and the controller interacts with the template detector 162 to receive a 10 bit template identification signal from the template detector. The controller also communicates with the USB port of the computer 10 at a data rate of 1.5 Mb/s. Power for the mouse pad is supplied by the computer system through the USB port and through cable 132 .
The smart card interface device may be implemented using one of a number of available devices that provide reading and writing capabilities to memories contained on a smart card, such as a GEMP PUBLIC KEY available from GEMPLUS of GEMENOS, FRANCE. In other embodiments, the smart card device may be a read-only device, such as a GPM103 available from GEMPLUS of GEMENOS, FRANCE.
As discussed above, the switches or buttons on the mouse pad 120 may be labeled using labels 126 a - 126 t on the template 140 . The template 140 is designed for use with a mouse pad in which the mouse pad is used to provide simplified Internet access. In this embodiment, as shown in FIGS. 2 and 3 , the buttons associated with labels 126 f - 126 i are respectively identified as “Home,” “Status,” “Call,” and “eMail.”
As described below, the computer system 110 is programmed to respond to a user's activation of these buttons to perform specific functions. Activation of the “Home,” button returns a user to a previously designated “Home” page on the Internet. Activation of the “Status” button provides the user with the status of their user account. Activation of the “Call” button may be used for example to notify a customer service representative for an e-commerce web site that the user of the system would like to have the customer service representative call the user on the telephone. The name and telephone number for the user may have been previously stored on the smart card, in the computer system or on the pad server and transferred over the Internet to the customer service representative. Activation of the “eMail” button is used to activate an email application on the computer system 110 , and allow the user to send and/or receive email messages.
In other embodiments of the present invention, additional function buttons may be used, such as a “Buy” button and a “Help” button. The “Buy” button may be used in conjunction with e-commerce web sites to simplify the process for buying products and services from these sites. When a user of the computer system has accessed a registered e-commerce web site, and has selected goods or services to purchase, activation of the “Buy” button causes information such as credit card information and delivery instructions to be sent to the e-commerce web site. The information sent to the e-commerce web site for a particular user may be preloaded in the computer system, stored in the pad web server, or stored in the smart card.
Activation by a user of the “Help” button causes a message to be sent over the Internet to the pad web server or a central customer service facility. The message may include contact information for the particular user to enable a service representative to contact the user by e-mail or telephone to provide help to the user.
In other embodiments, one of the fixed buttons may be designated as an “Ad” or “Coupon” button, the activation of which will connect the user to an Internet web site that contains coupons and advertisements that are updated periodically. In one embodiment of the present invention, coupons on a web site may be downloaded to the computer system and stored in the smart card. The user can then use the coupon in the smart card when purchasing goods either on line or at a traditional retail store having a smart card interface device that can detect the presence of the coupon on the user's smart card.
The buttons corresponding to labels 126 a to 126 e and 126 j to 126 t may also be programmed to perform specific functions, or alternatively, they may be pre-programmed to access a predefined internet web site. In some embodiments, the buttons may be programmable by the user to perform user-defined functions or to access user defined web sites.
In embodiments of the present invention, the computer system 110 and the web server 122 are programmed to support functions of the mouse pad described above and to support additional functions described below.
The computer system 110 includes a minibrowser software application 170 that provides the interface between the central processing unit of the computer system and the mouse pad and provides the interface for the computer system with the mouse pad server 220 through the internet browser. In one embodiment, the minibrowser includes software written in C++ that communicates with javaservlets on the Web server.
The interface between the minibrowser application 170 and the mouse pad 120 will now be described with reference to FIG. 6 . The minibrowser application 170 includes an event handler 172 and two application program interfaces (APIs), including a mouse pad API 174 for providing the primary interface for the mouse pad, and a smart card API 176 for providing the interface with the smart card.
The mouse pad API provides button and status functionality as well as control of the LEDs on the pad. An event is generated by the mouse pad API and received by the event handler when a button is pressed, when the template in the mouse pad is changed, and when a smart card is inserted or removed from the smart card device in the mouse pad.
The smart card API provides access to the data on the smart card itself. In one embodiment, the smart card only includes a single number that identifies the user of the mouse pad. For this embodiment, the smart card API includes a single function, identified as getCardNumber, for obtaining the number on the card. In other embodiments that use more complex smart cards, including cards that have both read and write capability, the smart card API may be implemented using Microsoft® Windows Smartcard API.
In one embodiment of the present invention, the minibrowser application is configured to be launched when the computer system 110 is first booted up. In other embodiments, the minibrowser may be launched by selecting a short cut on the desktop of the computer system or by selecting the program from a start menu on the computer system. FIG. 7 provides a flow chart of the initial operation 200 of the minibrowser immediately after launch. In a first step 202 of the operation, the minibrowser determines whether a mouse pad is coupled to the computer system. If the outcome of step 202 is “NO”, then an error message is displayed in step 204 . In other embodiments that do not require the presence of a mouse pad, if there is no mouse pad detected, the operation may proceed to step 220 . If the outcome of step 202 is “YES,” then the operation continues to step 206 .
In step 206 , the minibrowser determines whether the mouse pad version is compatible with the version of the minibrowser installed in the computer system. If the outcome of step 206 is “NO,” then in step 208 an error message is displayed on the computer screen. If the outcome of step 206 is “YES,” then the operation continues with step 210 .
In step 210 , the minibrowser determines whether there is a template in the mouse pad. If the outcome of step 210 is “NO,” then in step 212 an error message is displayed indicating that there is not a template present. In another embodiment of the present invention, rather than provide an error message when there is no template present, the minibrowser may generate a default template number (such as all zeros) corresponding to a pad with no template and then proceed to step 216 . If the outcome of step 210 is “YES,” then in step 214 , the number of the template is read and stored by the minibrowser.
The operation proceeds to step 216 , wherein the minibrowser determines whether there is a smart card present in the mouse pad. If a smart card is present, then in step 218 , the number for the smart card is read and provided to the minibrowser, and then the initial operation of the minibrowser proceeds to step 220 . If there is no smart card present, then the operation proceeds directly to step 220 . In some embodiments of the present invention, the absence of a smart card will limit the functions that a user may perform, and in one alternative embodiment, if no smart card is detected, the minibrowser will close. In other embodiments, when there is no smart card present, the user will be given the opportunity to enter a user identification number and password in place of the smart card.
In step 220 , the minibrowser evaluates locally cached data. The types of data that may be cached in different embodiments of the present invention are discussed further below. In step 222 , the minibrowser checks to see if there is an active Internet connection for the computer system. If the outcome of step 222 is “YES,” then in step 224 , a connection is made to the web server 122 to update the cached data. The procedure for downloading data from the web server 122 is described further below with reference to FIG. 12 . After step 224 , or if the outcome of step 222 is “NO,” then in step 226 , the minibrowser will render a graphical user interface.
The graphical user interfaces rendered on the screen 180 of the computer system 110 will now be described with reference to FIGS. 8-11 . After the minibrowser completes the initial operation shown in FIG. 6 , it generates a small floating palette handle 182 on the edge of the screen 180 and also creates an icon 184 that appears in the systray 186 .
When a user of the computer system 110 selects the palette handle 182 (using, for example, the mouse 118 ), the palette handle expands (as shown in FIG. 9 ) to display a number of category buttons 188 . In one embodiment of the present invention, the palette also may be expanded by pressing any of the buttons 126 on the mouse pad 120 . The category buttons may include for example a “Sports” button, a “News” button, a “Shopping” button, and a “Travel” button. In the embodiment shown, 6 category buttons are displayed, however, in other embodiments more or less category buttons may be used. When a category button is selected, the contents of the category are displayed, as shown in FIG. 10 . The contents may include a number of buttons 190 , each of which corresponds to an Internet web site having content related to the particular category. Upon the selection of a button 190 , the minibrowser launches the web browser and accesses the pad web server 122 . The pad web server 122 provides a redirection to the internet web site corresponding to the button, and a web page of that web site is displayed in the web browser window 192 on the screen 180 (see, FIG. 11 ).
In addition to the category and content buttons shown in FIGS. 8-11 , in some embodiments of the present invention, the expanded minibrowser palette may have advertisement slots. The advertisement slots are used to display advertisements. The particular advertisements displayed may be determined in part by the particular template that is installed in the mouse pad and by demographics of the user.
In one embodiment, each of the category buttons 188 has a corresponding category button 126 on the mouse pad, and actuation of the category button on the mouse pad causes the contents of the category to be displayed on the screen. As described further below, the particular categories displayed (and/or the contents of the categories) by the minibrowser may be determined by the particular template that is installed in the mouse pad to match a theme of the particular template.
As described above, in embodiments of the present invention, data used by the minibrowser is downloaded from the pad web server and stored in cache. This prevents waiting times that might be encountered, if the minibrowser sought to download data from the pad web server whenever the data was needed. In one embodiment, the minibrowser updates the cached data either upon initiation of the minibrowser (if an Internet connection is already in place), or when a connection is made to the Internet through the minibrowser. This embodiment is particularly desirable for users that have dial-up Internet connections and may be inconvenienced by an automatic Internet connection occurring at an inopportune time.
In other embodiments, the minibrowser may connect to the web server for updates on a periodic basis by establishing an Internet connection through the Internet browser at appropriate times.
In embodiments of the present invention, to ensure that cached data is current, the system includes a start date and an end date for each set of cached data. The start dates and end dates are used to determine if a data set is current. In addition, attempts are made to provide data to the minibrowser several days in advance of its start date to ensure that the data is available when needed. The system includes default settings that allow the system to operate if current data is not available.
The cached data for the minibrowser includes pad data, smart card data, template data, category data, help data and advertisement data. Table 1 below includes a listing of the data that is cached in the minibrowser in one embodiment of the present invention.
TABLE 1
Minibrowser Cached Data
Title
Description
Pad Version
Identifies a version number of the mouse pad coupled to
the computer system.
Pad Status
Indicates the status of the mouse pad as either OK,
Absent, or Error.
Account Status
Indicates the status of the account for the present user as
either OK, New, Deactivated, or Special.
Card Numbers
Includes a list of all card number that have been used
with the computer system along with attributes of the
card including user name, status, activation date,
expiration data, templates that have been used with the
card, attributes of the templates including button IDs and
minibrowser advertisements for the templates.
Content Items
Includes the contents and attributes for each of the
category and content buttons of the minibrowser.
Link Items
Includes a number of Web site targets, application targets
which are defined on a user's computer and/or macros.
The web server 122 is implemented in embodiments of the present invention using standard web server products such as Sun Netras and Solaris from Sun Microsystems, Apache Stronghold, Oracle Database Server 8 , Jrun from Allaire, and in addition the web server includes software for performing specialized functions. The software for implementing these functions is written in Java and Java Server Pages. In one embodiment there are five primary functions provided by the web server software, including: 1) link redirecting for web site selections made on the minibrowser or the mouse pad; 2) providing responses to minibrowser requests; 3) producing web pages for a public version of a web site to be accessed by registered and non-registered users; 4) producing user service web site pages; and 5) providing back office access for a system administrator. Each of these functions is described in greater detail below.
The link redirection function redirects a user from the pad web server to an actual web site selected by the user using a button on the minibrowser or the mouse pad. When a user selects a web site button on either the minibrowser or mouse pad, the minibrowser launches the web browser and prepares and sends a link message to the pad web server. In one embodiment, the link message may include: a link item target that identifies the particular button on the minibrowser or the mouse pad that was selected; the number of the smart card loaded into the mouse pad; the identification number of the template loaded into the mouse pad; and the version of the pad being used. From the information provided in the message, the pad web server reviews its database, retrieves a URL for the web site identified by the button selected, and provides a redirection to that web site.
In some embodiments of the present invention, the pad web server maintains a log of all redirection activity. The log is particularly useful for tracking activities of users for billing purposes. Specifically, the log may be used to determine how often users have accessed the web site of a third party, and the third party can then be billed based on the number of “hits” generated through the use of mouse pads and minibrowsers.
As discussed above, upon initial loading, or at other predetermined times, the minibrowser requests data updates from the pad web server. The web server responds to the requests by searching the database for the requested data and sending it to the minibrowser. In one embodiment, the requests from the minibrowser and the responses from the pad web server are sent during down times of an Internet connection by the user to prevent interference with the user's internet session.
In embodiments of the present invention, the pad web server includes HTML code for generating publicly accessible Internet web pages to allow Internet users to order the mouse pads 120 and the minibrowser software and to establish user accounts. In addition, the web pages may provide a listing of favorite sites and may include banner advertisements.
In addition to the public web pages, in embodiments of the present invention, the pad web server includes HTML code for generating limited access Internet web pages. The limited access Intenet web pages may be accessed by registered users either directly using a button on the minibrowser or the mouse pad, or indirectly through one of the public web pages by entering an account number and/or password. The limited access web pages allow users to change user account information, obtain additional information regarding services available, and obtain trouble shooting information or more general help information.
The pad web server also includes back office software that allows a system administrator to log onto the server, update data contained in the databases of the server, access log data print reports, update the web pages and provide other administration functions.
The database of the pad web server, as discussed above, contains data that is sent in response to requests from the minibrowser. In one embodiment of the present invention, the data stored in the database includes the data shown in Table 2. In addition to the fields shown in Table 2, other data may be included for other embodiments of the present invention.
TABLE 2
Server Database Fields
Title
Description
Card Number Dataset
Includes information for each card number
including state of card (i.e, active or inactive),
activation date, expiration date, list of
templates that may be used with the card,
history (i.e., list of transactions for the card),
and a pointer to the user dataset.
User Dataset
Includes name, address, phone numbers, email
addresses.
Template Dataset
Distribution information, validity start date and
expiration date, current buttonset, future button
set, button set history.
ButtonSet
Includes for each template, list of buttons with
IDs and pointers, and description of
advertisement IDs and minibrowser slots.
Content Items
Includes attributes of content items.
Link Items
Includes attributes of link items.
Client/Partner Dataset
Includes attributes of partners including contact
data, billing data, destination list to create link
items, information related to advertisements
In addition to the systems described above, embodiments of the present invention are also directed to methods of using theses systems and methods of conducting business using these systems. One such method 300 will now be described further with reference to FIG. 12 . In a first step 302 of the method 300 , an owner or operator of the pad server will provide the mouse pads, templates, minibrowser software and installation software for the minibrowser software to e-commerce partners. The pads may be sold to the partners or in one business model may be provided to the partners free of charge. Each e-commerce partner can have a custom template for the mouse pad having internet access buttons (and/or minibrowser buttons) directed to, for example, e-commerce web sites controlled by the partner or sites having a prearranged agreement with the partner.
In step 304 of the method 300 , the mouse pads and software are distributed to potential users by the e-commerce partners. The distribution to the users may be as part of a sale or license, or the mouse pads and software may be provided free of charge as part of a promotional program by the e-commerce partner. Smart cards may be distributed with the pads, or as smart cards become more prevalent, the user may already have a smart card that can be used with the mouse pad. In one embodiment of the present invention, the software includes additional software to allow the users to connect to and establish service with an Internet service provider (ISP).
After receiving the pad, in step 306 , the user installs the software and the pad in the user's computer system, and in step 308 , following initiation instructions for a new user generated by the minibrowser, the user contacts the pad web server to register with the system.
In step 310 of the method 300 , the user selects a button corresponding to a web site on either the mouse pad or the minibrowser. Next in step 312 , the minibrowser contacts the pad web server through the computer system's browser, and in step 314 , the pad web server provides a redirection to the selected web site. Once at the selected site, the user may browse through several web pages to find an object to purchase. The user then selects the object and in step 316 presses the “Buy” key on either the minibrowser or the mouse pad to buy the object. As discussed above, the user's shipping and credit card information may be stored in the smart card, in the pad web server or in the minibrowser. After the “Buy” button is pressed, in step 318 the web site contacts the pad web server which in step 320 provides the necessary shipping and credit card information from either its own database or by retrieving it from the minibrowser. The user may then purchase other items from the present web site or select a different button to access another web site.
In one embodiment of the present invention, before the credit card and delivery information is provided to the web site, the web site is required to provide information regarding the object being sold, including the sales price. This information may be logged by the pad web server and used to determine royalty payments due by the e-commerce partner as described below.
The owner of the pad server may generate revenue in one of several ways, examples of which will now be described. In one embodiment, in lieu of or in addition to charging an e-commerce partner for the mouse pads, a fee can be collected from the e-commerce partner for each redirection that is performed by the pad web server from a user of a mouse pad distributed by the e-commerce partner. An additional fee may be charged if the redirection is to a web site owned or controlled by the e-commerce partner, and yet an additional fee or royalty payment may be charged to the e-commerce partner for any purchases made by a user accessing the internet using the mouse pad. As discussed above with reference to FIG. 12 , logs of transactions can be maintained by the pad web server, and these logs can be used to generate reports from which bills to e-commerce partners may be generated.
The use of the smart card with the mouse pad 120 and computer system 110 in embodiments of the present invention provides a number of advantages and simplifies access to the internet and simplifies the e-commerce process. A user of the computer system 110 may access the internet by first placing the user's smart card in the slot 28 of the mouse pad. The system is then able to identify the user based on information stored in the smart card. In some embodiments, the system prompts the user to enter a personal identification number (PIN) before enabling all of the features of the smart pad. In place of the PIN system other security controls may be used to ensure that the user is authorized to use the smart card.
Once the user is authenticated, the user may press one of the previously described buttons on the mouse pad to access the internet and purchase goods and services. In some embodiments, the content of the display (including advertisements) provided by the portal to the user, as well as the programming of the buttons on the mouse pad, may be tailored to the user based on information stored in the smart card. The information on the smart card may also include demographical data that can be used by web sites accessed by the user to tailor advertisements to the user and to allow the web sites to establish demographic profiles and trends of each user. In another embodiment, the buttons may be programmed by the user by connecting to a predetermined Internet web site and entering either specific web sites to which the buttons will be programmed or by entering categories or types of web sites.
In embodiments of the present invention, the smart card may also provide functions of an electronic wallet. As discussed above, identification information of the user may be stored in the smart card, and in addition, the smart card may include typical debit and credit card capabilities. Also, the smart card may be used in conjunction with the computer system 110 to store promotional material such as coupons, discounts or even gift certificates that may be downloaded from Internet sites and stored in the smart card. These coupons and gift certificates may be used by the user when accessing e-commerce sites through the computer system 110 or may be used by the user at traditional retail outlets that are equipped with smart card readers.
In another embodiment of the present invention, the smart card may be used to store electronic event tickets purchased from an e-commerce web site and downloaded to the smart card using the computer system 110 . The smart card may then be used in conjunction with smart card readers at various event locations to validate that the user has purchased a ticket to the event.
In embodiments of the present invention discussed above, the mouse pad 122 has a pad area 124 designed for use with a standard mouse. In other embodiments, other input/output devices such as roller balls, joysticks or other devices may be incorporated in the mouse pad in addition to or in place of the pad area 124 .
In the embodiments described above, the computer system 110 provides an interface to the Internet for a user having a smart card. As understood by those skilled in the art, computer systems, like computer system 110 , may be placed in a number of public places such as retail stores, malls or other facilities, and these computer systems may be used in conjunction with the smart card to provide a personalized, secure Internet experience. In such an embodiment, the user may be charged for use based on the time that the user is connected.
In embodiments described above, a simplified Internet access device is incorporated in a mouse pad. In other embodiments of the present invention, Internet access devices are incorporated in keyboards, monitors and other computer peripherals to provide simplified access to the internet and to simplify the process for purchasing goods and services over the internet. For example, in one embodiment, a keyboard has an alternate mode of operation wherein the standard keys on the keyboard are programmed as Internet access keys to provide direct access to Internet web sites and to provide the functionality of the keys of the mouse pad 122 discussed above. Alternatively, additional Internet access keys may be added to a standard keyboard. In addition, keyboards and mouse pads of the present invention may include an LCD screen to display information in addition to that shown on a typical monitor. In another embodiment Internet access keys may be added to the area surrounding the screen on a monitor. Templates, like the template used with the mouse pad 120 may be used with the embodiments of the present invention that incorporate internet access buttons in keyboards and monitors.
In embodiments of the present invention described above, the computer system 110 includes a mouse pad having buttons for accessing the Internet. In other embodiments, the computer system 110 need not have a mouse pad, but may still have a minibrowser having programmed buttons for accessing the Internet. The minibrowser buttons may be programmed by the user either through the computer system alone or by accessing a customization page provided on the pad web server. In this embodiment, smart cards may still be used by connecting a smart card reader directly to the computer system.
In embodiments of the present invention described above, a smart card read/write device is incorporated in an electronics housing of the mouse pad 120 . In other embodiments, the smart card read/write device may be a removable, optional device that connects to the electronics housing of the mouse pad 120 or the mouse pad may not include a smart card read/write device at all. Further, the mouse pad 120 is shown coupled to the USB of the computer system using a cable 132 . In other embodiments, the connection between the mouse pad and the computer system may be, for example, a wireless connection using RF technology or infrared technology.
Internet access systems described above, in addition to providing simplified access to the Internet, may also be used to provide controlled and/or limited access to the Internet. In embodiments of the present invention, a user's access to the Internet may be limited to only those web sites having a button on the mouse pad or minibrowser. Using such an embodiment, teachers can limit a student's access to a particular set of Internet web sites, and similarly, parents can limit their childrens' access to only pre-selected web sites. In these embodiments, the parents and/or the teachers may have security codes that allow them to reprogram the buttons on the mouse pad and minibrowser.
Mouse pads of the present invention having programmable buttons are used to provide simplified Internet access. In other embodiments, the mouse pads may be used to control functions of a computer system other than Internet functions.
Having thus described at least one illustrative embodiment of the invention, various alterations, modifications and improvements will readily occur to those skilled in the art. Such alterations, modifications and improvements are intended to be within the scope and spirit of the invention. Accordingly, the foregoing description is by way of example only and is not intended as limiting. The invention's limit is defined only in the following claims and the equivalence thereto.
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A system for providing access to a computer network comprises a first computer operatively coupled to the computer network and a second computer operatively coupled to the computer network. A peripheral device, which is coupled to the first computer, includes a plurality of buttons. If one of the plurality of buttons is activated, the first computer responds by communicating a signal to the second computer over the computer network. The second computer is constructed and arranged to respond to the signal communicated from the first computer by redirecting the signal to a third computer to establish a network connection between the first computer and the third computer over the computer network.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of and commonly owned U.S. patent application Ser. No. 13/213,973, filed Aug. 19, 2011; which is a continuation-in-part application of co-pending and commonly owned U.S. patent application Ser. No. 09/861,219, filed May 18, 2001, now U.S. Pat. No. 8,037,733; which claims the benefit of priority from U.S. Provisional Patent Application Ser. No. 60/206,060, filed May 19, 2000, now expired; and is a continuation-in-part of co-pending and commonly owned U.S. patent application Ser. No. 09/716,146, filed Nov. 17, 2000, now U.S. Pat. No. 8,252,044; and is a continuation-in-part of co-pending and commonly owned U.S. patent application Ser. No. 13/103,576, filed May 9, 2011, now U.S. Pat. No. 8,632,583, each of which is hereby incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] The invention relates to methods and apparatus for manufacturing medical devices, including endoluminal stents, wherein the medical device has at least one groove on at least a first surface of the device that is generally in contact with endothelial tissue and blood flow when implanted within the body. A drug-eluting polymer is disposed within the groove, but does not otherwise cover the surface of the endoluminal stent, the groove having a drug-eluting polymer treated to promote the migration of endothelial cells onto the inner surface of the intravascular stent.
[0003] Various types of intravascular or endoluminal stents have been used in recent years. An intravascular stent generally refers to a device used for the support of living tissue during the healing phase, including the support of internal structures. Intravascular stents, or stents, placed endoluminally, as by use of a catheter device, have been demonstrated to be highly efficacious in initially restoring patency to sites of vascular occlusion. Intravascular stents, or stents, may be of the balloon-expandable type, such as those of U.S. Pat. Nos. 4,733,665; 5,102,417; or 5,195,984, which are distributed by Johnson & Johnson Interventional Systems, of Warren, N.J., as the PALMAZ and the PALMAZ-SCHATZ balloon-expandable stents or balloon expandable stents of other manufacturers, as are known in the art. Other types of intravascular stents are known as self-expanding stents, such as Nitinol coil stents or self-expanding stents made of stainless steel wire formed into a zigzag tubular configuration.
[0004] Intravascular stents are used, in general, as a mechanical means to solve the most common problems of percutaneous balloon angioplasty, such as elastic recoil and intimal dissection. One problem intraluminal stent placement shares with other revascularization procedures, including bypass surgery and balloon angioplasty, is restenosis of the artery. An important factor contributing to this possible reocclusion at the site of stent placement is injury to, and loss of, the natural nonthrombogenic lining of the arterial lumen, the endothelium. Loss of the endothelium, exposing the thrombogenic arterial wall matrix proteins, along with the generally thrombogenic nature of prosthetic materials, initiates platelet deposition and activation of the coagulation cascade. Depending on a multitude of factors, such as activity of the fibrinolytic system, the use of anticoagulants, and the nature of the lesion substrate, the result of this process may range from a small mural to an occlusive thrombus. Secondly, loss of the endothelium at the interventional site may be critical to the development and extent of eventual intimal hyperplasia at the site. Previous studies have demonstrated that the presence of an intact endothelial layer at an injured arterial site can significantly inhibit the extent of smooth muscle cell-related intimal hyperplasia. Rapid re-endothelialization of the arterial wall, as well as endothelialization of the prosthetic surface, or inner surface of the stent, are therefore critical for the prevention of low-flow thrombosis and for continued patency. Unless endothelial cells from another source are somehow introduced and seeded at the site, coverage of an injured area of endothelium is achieved primarily, at least initially, by migration of endothelial cells from adjacent arterial areas of intact endothelium.
[0005] Those skilled in the art will understand that the term “intravascular stent” is intended to mean a stent that is placed within the body's vascular system. It will also be understood that the term “endoluminal stent” is intended to mean a stent that is placed within a body lumen. The vascular system being luminal, the term “endoluminal” is understood to encompass “intravascular” but not the reverse. While the present invention is described with specific reference to intravascular stents, one skilled in the art will understand that endoluminal stents are also contemplated as being within the scope of the invention.
[0006] Although an in vitro biological coating to a stent in the form of seeded endothelial cells on metal stents has been previously proposed, there are believed to be serious logistic problems related to live-cell seeding, which may prove to be insurmountable. Thus, it would be advantageous to increase the rate at which endothelial cells from adjacent arterial areas of intact endothelium migrate upon the inner surface of the stent exposed to the flow of blood through the artery. At present, most intravascular stents are manufactured of stainless steel and such stents become embedded in the arterial wall by tissue growth weeks to months after placement. This favorable outcome occurs consistently with any stent design, provided it has a reasonably low metal surface and does not obstruct the fluid, or blood, flow through the artery. Furthermore, because of the fluid dynamics along the inner arterial walls caused by blood pumping through the arteries, along with the blood/endothelium interface itself, it has been desired that the stents have a very smooth surface to facilitate migration of endothelial cells onto the surface of the stent. In fact, it has been reported that smoothness of the stent surface after expansion is crucial to the biocompatibility of a stent, and thus, any surface topography other than smooth is not desired. Christoph Hehriein, et. al., Influence of Surface Texture and Charge On the Biocompatibility of Endovascular Stents, Coronary Artery Disease, Vol. 6, pages 581-586 (1995). After the stent has been coated with serum proteins, the endothelium grows over the fibrin-coated metal surface on the inner surface of the stent until a continuous endothelial layer covers the stent surface, in days to weeks. Endothelium renders the thrombogenic metal surface protected from thrombus deposition, which is likely to form with slow or turbulent flow. At present, all intravascular stents made of stainless steel, or other alloys or metals, are provided with an extremely smooth surface finish, such as is usually obtained by electropolishing the metallic stent surfaces. Although presently known intravascular stents, specific including the PALMAZ and the PALMAZ-SCHATZ balloon-expandable stents have been demonstrated to be successful in the treatment of coronary disease, as an adjunct to balloon angioplasty, intravascular stents could be even more successful and efficacious, if the rate and/or speed of endothelial cell migration onto the inner surface of the stent could be increased. It is believed that providing at least one groove disposed in the inner surface of a stent increases the rate of migration of endothelial cells upon the inner surface of the stent after it has been implanted. Accordingly, the art has sought methods and apparatus for manufacturing an intravascular stent with at least one groove disposed in the inner surface of the stent.
[0007] The present invention relates generally to an implantable device for in vivo delivery of bioactive compounds. The present invention provides an implantable structural material having a three-dimensional conformation suitable for loading a bioactive agent into the structural material, implanting the structural material in vivo and releasing the bioactive agent from the structural agent to deliver a pharmacologically acceptable level of the bioactive agent to an internal region of a body. More particularly, the present invention relates to an implantable medical device, such as an endoluminal stent, stent-graft, graft, valves, filters, occluders, osteal implant or the like, having cavitated regions with micropores that communicate a bioactive agent from the cavity to an area external the stent.
[0008] The present invention may be used for any indication where it is desirable to deliver a bioactive agent to a local situs within a body over a period of time. For example, the present invention may be used in treating vascular occlusive disease, disorders or vascular injury, as an implantable contraceptive for delivery of a contraceptive agent delivered intrauterine or subcutaneously, to carry an anti-neoplastic agent or radioactive agent and implanted within or adjacent to a tumor, such as to treat prostate cancer, for time-mediated delivery of immunosuppresents, antiviral or antibiotic agents for treating of autoimmune disorders such as transplantation rejection or acquired immune disorders such as HIV, or to treat implant or non-implant-related inflammation or infections such as endocarditis.
[0009] Occlusive diseases, disorders or trauma cause patent body lumens to narrow and restrict the flow or passage of fluid or materials through the body lumen. One example of occlusive disease is arteriosclerosis in which portions of blood vessels become occluded by the gradual build-up of arteriosclerotic plaque, this process is also known as stenosis. When vascular stenosis results in the functional occlusion of a blood vessel the vessel must be returned to its patent condition. Conventional therapies for treatment of occluded body lumens include dilatation of the body lumen using bioactive agents, such as tissue plasminogen activator (TPA) or vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) gene transfers which have improved blood flow and collateral development in ischemic limb and myocardium (S. Yla-Herttuala, Cardiovascular gene therapy , Lancet, Jan. 15, 2000), surgical intervention to remove the blockage, replacement of the blocked segment with a new segment of endogenous or exogenous graft tissue, or the use of a catheter-mounted device such as a balloon catheter to dilate the body lumen or an artherectomy catheter to remove occlusive material. The dilation of a blood vessel with a balloon catheter is called percutaneous transluminal angioplasty. During angioplasty, a balloon catheter in a deflated state is inserted within an occluded segment of a blood vessel and is inflated and deflated a number of times to expand the vessel. Due to the inflation of the balloon catheter, the plaque formed on the vessel walls cracks and the vessel expands to allow increased blood flow through the vessel.
[0010] In approximately sixty percent of angioplasty cases, the blood vessel remains patent. However, the restenosis rate of approximately forty percent is unacceptably high. Endoluminal stents of a wide variety of materials, properties and configurations have been used post-angioplasty in order to prevent restenosis and loss of patency in the vessel.
[0011] While the use of endoluminal stents has successfully decreased the rate of restenosis in angioplasty patients, it has been found that a significant restenosis rate continues to exist even with the use of endoluminal stents. It is generally believed that the post-stenting restenosis rate is due, in major part, to a failure of the endothelial layer to regrow over the stent and the incidence of smooth muscle cell-related neointimal growth on the luminal surfaces of the stent. Injury to the endothelium, the natural nonthrombogenic lining of the arterial lumen, is a significant factor contributing to restenosis at the situs of a stent. Endothelial loss exposes thrombogenic arterial wall proteins, which, along with the generally thrombogenic nature of many prosthetic materials, such as stainless steel, titanium, tantalum, Nitinol, etc. customarily used in manufacturing stents, initiates platelet deposition and activation of the coagulation cascade, which results in thrombus formation, ranging from partial covering of the luminal surface of the stent to an occlusive thrombus. Additionally, endothelial loss at the site of the stent has been implicated in the development of neointimal hyperplasia at the stent situs. Accordingly, rapid re-endothelialization of the arterial wall with concomitant endothelialization of the body fluid or blood contacting surfaces of the implanted device is considered critical for maintaining vasculature patency and preventing low-flow thrombosis. To prevent restenosis and thrombosis in the area where angioplasty has been performed, anti-thrombosis agents and other biologically active agents can be employed.
[0012] It has been found desirable to deliver bioactive agents to the area where a stent is placed concurrently with stent implantation. Many stents have been designed to delivery bioactive agents to the anatomical region of stent implantation. Some of these stents are biodegradable stents which are impregnated with bioactive agents. Examples of biodegradable impregnated stents are those found in U.S. Pat. Nos. 5,500,013, 5,429,634, and 5,443,458. Other known bioactive agent delivery stents include a stent disclosed in U.S. Pat. No. 5,342,348 in which a bioactive agent is impregnated into filaments which are woven into or laminated onto a stent. U.S. Pat. No. 5,234,456 discloses a hydrophilic stent that may include a bioactive agent adsorbed which can include a biologically active agent disposed within the hydrophilic material of the stent. Other bioactive agent delivery stents disclosed in U.S. Pat. Nos. 5,201,778, 5,282,823, 5,383,927; 5,383,928, 5,423,885, 5,441,515, 5,443,496, 5,449,382, 4,464,450, and European Patent Application No. 0 528 039. Other devices for endoluminal delivery of bioactive agents are disclosed in U.S. Pat. Nos. 3,797,485, 4,203,442, 4,309,776, 4,479,796, 5,002,661, 5,062,829, 5,180,366, 5,295,962, 5,304,121, 5,421,826, and International Application No. WO 94/18906. A directional release bioactive agent stent is disclosed in U.S. Pat. No. 6,071,305 in which a stent is formed of a helical member that has a groove in the abluminal surface of the helical member. A bioactive agent is loaded into the groove prior to endoluminal delivery and the bioactive agent is therefore in direct apposition to the tissue that the bioactive agent treats. Finally, International Application No. WO 00/18327 discloses a drug delivery stent in which a tubular conduit is wound into a helical stent. The tubular conduit has either a single continuous lumen or dual continuous lumens that extend the entire length of the conduit. The tubular conduit has regions or segments thereof that has pores to permit drug “seepage” from the conduit. One end of the tubular conduit is in fluid flow communication with a fluid delivery catheter, which introduces a fluid, such as drug into the continuous lumen and through the pores.
[0013] Where bioabsorbable or non-bioabsorbable polymer-based or polymer-coated stents have been used, the polymers may cause an immune inflammatory response once the drug is eluted out of the polymer. Where a polymer is employed as the bioactive agent carrier, it is, therefore, desirable to either isolate or limit exposure of the polymer to body tissues in order to reduce or limit the possibility of immune inflammatory response after the bioactive agent has eluted. By disposing the polymer only in the grooves leaving the remaining device surface uncovered, the contact or surface are for interaction between tissue and polymer is limited.
SUMMARY OF THE INVENTION
[0014] As used herein the term “bioactive agent” is intended to include one or more pharmacologically active compounds which may be in combination with pharmaceutically acceptable carriers and, optionally, additional ingredients such as antioxidants, stabilizing agents, permeation enhancers, and the like. Examples of bioactive agents which may be used in the present invention include but are not limited to antiviral drugs, antibiotic drugs, steroids, fibronectin, anti-clotting drugs, anti-platelet function drugs, drugs which prevent smooth muscle cell growth on inner surface wall of vessel, heparin, heparin fragments, aspirin, coumadin, tissue plasminogen activator (TPA), urokinase, hirudin, streptokinase, antiproliferatives, e.g., methotrexate, cisplatin, fluorouracil, Adriamycin, antioxidants, e.g., ascorbic acid, beta carotene, vitamin E, antimetabolites, thromboxane inhibitors, non-steroidal and steroidal anti-inflammatory drugs, immunosuppresents, such as rapomycin, beta and calcium channel blockers, genetic materials including DNA and RNA fragments, complete expression genes, antibodies, lymphokines, growth factors, e.g., vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF)), prostaglandins, leukotrienes, laminin, elastin, collagen, nitric oxide (NO) and integrins.
[0015] The use of the term “groove” is intended to be construed as an elongate channel, recess or depression, having a length, a width and a depth, the length being greater than the width and the depth being less than a distance between the first surface and second surface of the medical device. The groove may have a wide variety of transverse cross-sectional shapes as described hereinafter, and may have a wide variety of elongate shapes, including linear, curvilinear, meandering, zigzag, sinusoidal, or the like relative to the surface in which the groove resides. The groove may also have constant or variable widths and depths along its length. Provided, however, that at no point along the groove's length may the depth of the groove be greater than the distance between the first surface and second surface of the medical device, that is, a groove is not a slot, even where the slot may be bounded by or in close proximity with an adjacent layer of material, such as in a coiling tubular sheet stent. In the instance of medical device consisting of a coiled sheet of material having successive adjacent layers of the sheet material, the grooves will have a depth less than the thickness of the single sheet before it is coiled and not pass through or form slots passing through any single layer of a coiled medical device.
[0016] The inventive structural material has a three dimensional conformation having a geometry and construction in there is at least one groove in a surface of the structural material and a vehicle or carrier, such as a polymer, for holding or adsorbing the bioactive agent and permitting it to elute from the vehicle or carrier once implanted into the body. The bioactive agent vehicle is disposed only in the at least one groove and does not otherwise cover the surface of the structural material. The three dimensional conformation of the structural material may assume a cylindrical, tubular, planar, spherical, curvilinear or other general shape which is desired and suited for a particular implant application. For example, in accordance with the present invention there is provided an endoluminal stent that is made of a plurality of structural members that define a generally tubular shape for the endoluminal stent. At least some of the plurality of structural members are comprised of the inventive structural material and have at least one groove on at least an inner surface of the stent. Alternate types of implantable devices contemplated by the present invention include, without limitation, stent-grafts, grafts, heart valves, venous valves, filters, occlusion devices, catheters, osteal implants, implantable contraceptives, implantable anti-tumor pellets or rods, or other implantable medical devices.
[0017] In accordance with one embodiment of the present invention, there is provided an endoluminal stent for delivery of bioactive agents. The stent may have plural structural elements or may be made of a single structural element formed into a generally tubular, diametrically expansible stent. At least one groove is provided in at least one of the luminal or inner surface or the abluminal or outer surface of the stent that retains the bioactive agents and permits elution of the bioactive agent therefrom. The at least one groove may be linear, curved, serpentine, zigzag or other configuration in the surface of the stent such that when implanted, at least a portion of the at least one groove is oriented generally parallel to an axis of blood flow within a blood vessel to promote endothelial cell migration and proliferation along the axis of the at least one groove.
[0018] In accordance with another embodiment of the present invention, there is provided a metal thin film, coiling stent, formed of a planar sheet of metal thin film which is coiled into a tubular structure having successive windings of the planar sheet of metal thin film. At least one surface of the planar sheet of metal thin film has at least one groove in the surface such that upon coiling, the at least one groove resides, in full or at least in part, on either the ultimate outer or abluminal surface or the ultimate inner or luminal surface of the coiled stent.
[0019] In accordance with still another embodiment of the present invention there is provided a bioabsorbable polymer formed in a solid or tubular cylindrical shape and having a bioactive agent associated therewith and elutable therefrom. At least one of a plurality of grooves are formed on at least an outer surface of the polymeric cylinder. The cylinder is implantable sub-dermally and the grooves serve to promote endothelial cell growth onto and across the surface Other than described herein, the present invention does not depend upon the particular geometry, material, material properties or configuration of the stent.
[0020] In accordance with the invention, the foregoing advantage has been achieved through the present methods and apparatus for manufacturing an endoluminal stent with at least one groove disposed in the inner surface of the stent.
[0021] In one embodiment of the present invention, there is provided a method of manufacturing a endoluminal stent by first forming a stent having an inner surface and an outer surface; and then forming at least one groove in the inner surface of the stent by etching the inner surface with a mechanical process.
[0022] Various mechanical etching processes can be used. In one preferred embodiment, a mandrel is placed inside the stent, and then a mechanical force is provided to impart at least one groove formed on the outer surface of the mandrel to the inner surface of the stent. Such mechanical force may be provided by one or more calendaring rollers rotating against the outer surface of the stent, or by one or more stamping devices disposed about the outer surface of the stent. The mandrel may have an outer diameter equal to the inner diameter of the stent when the stent is expanded.
[0023] In another preferred embodiment, the mechanical etching process may comprise the steps of placing an impression roller inside the stent, and rotating the impression roller within the stent to impart at least one groove formed on the exterior of the impression roller into the inner surface of the stent.
[0024] In still another preferred embodiment, the mechanical etching process may comprise the steps of disposing the stent upon an expanding mandrel in the unexpanded configuration of the mandrel, and then expanding the mandrel outwardly to impart at least one groove on the outer surface of the mandrel to the inner surface of the stent. Particularly, the expanding mandrel may be formed of a plurality of mating and tapered segments having at least one groove on the outer surface.
[0025] In another preferred embodiment, the mechanical etching process may comprise the step of moving a tapered mandrel into and along the inner surface of the stent. During the movement, the tapered mandrel provides a cutting force, which cuts at least one groove onto the inner surface of the stent. Particularly, the stent is in an expanded configuration, and the tapered mandrel either has a plurality of cutting teeth on its outer surface, or has an outer surface with a metal cutting profile. More particularly, the cutting teeth may be abrasive particles including diamond chips and tungsten carbide chips.
[0026] In another embodiment of the present invention, there is provided a method of manufacturing a metallic intravascular stent by first forming a stent having an inner surface and an outer surface; and then forming at least one groove on the inner surface of the stent by etching the inner surface with a chemical process. Preferably, the chemical process may comprise the steps of coating the inner surface of the stent with a photosensitive material; inserting a mask into the stent; irradiating the inner surface of the stent by a light source; removing the mask from the stent; and etching light exposed areas to produce at least one groove. In the inner surface of the stent. The mask may be disposed upon a deflated balloon before its insertion, and the balloon becomes expanded after the insertion. The light source may be a coaxial light source with multiple beams of light in a single plane, and may be displaced along the longitudinal axis of the stent. During the etching process, either the light source may be driven by a stepper motor for rotational movements, or the mask may be driven for rotational movements with the light source fixed.
[0027] In still another embodiment of the present invention, there is provided a method of manufacturing a metallic intravascular stent by first forming a stent having an inner surface and an outer surface; and then forming at least one groove on the inner surface of the stent by etching the inner surface with a laser.
[0028] In yet another embodiment of the present invention, there is provided a method of manufacturing a metallic intravascular stent by first forming a stent having an inner surface and an outer surface; and then forming at least one groove in the inner surface of the stent by etching the inner surface with an electric discharge machining process. The electric discharge machining process may include the steps of inserting an electric discharge machining electrode into the stent; rotating the electrode within the stent; and providing current to the electrode to cut at least one groove into the inner surface of the stent.
[0029] It has been found that by providing at least one groove on the inner surface of an endoluminal stent, the rate of endothelial cell attachment onto the stent and the rate of migration of endothelial cells along the grooves and the inner surface of the stent is also increased. This leads to a significantly more rapid development of a healthy endothelium at the site of stent placement.
[0030] In still another embodiment of the present invention, there is provided a stent having at least one groove on the inner surface of the stent and a drug-eluting polymer is disposed within the groove, but not otherwise on the inner surface of the stent. This configuration will allow the benefits of the more rapid development of a healthy endothelium than that associated with stents not having the groove, as well as the benefits from the presence of bioactive agents or drugs that can act to suppress cellular
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a partial cross sectional perspective view of a portion of a intravascular stent embedded within an arterial wall of a patient;
[0032] FIG. 2 is an exploded view of the outlined portion of FIG. 1 denoted as FIG. 2 ;
[0033] FIG. 3 is a partial cross-sectional, perspective view corresponding to FIG. 1 after the passage of time;
[0034] FIG. 4 is an exploded view of the outlined portion of FIG. 3 denoted as FIG. 4 ;
[0035] FIG. 5 is a partial cross-sectional view of the stent and artery of FIGS. 1 and 3 after a further passage of time;
[0036] FIG. 6 is an exploded view of the outlined portion of FIG. 5 denoted as FIG. 6 ;
[0037] FIG. 7 is a partial cross-sectional view of the stent and artery of FIG. 5 , taken along lines 7 - 7 of FIG. 5 , and illustrates rapid endothelialization resulting in a thin neointimal layer covering the stent;
[0038] FIG. 8 is a plan view of an interior portion of an unexpanded intravascular stent in accordance with the present invention;
[0039] FIGS. 9-16 are various embodiments of an exploded view of a groove taken along line 9 - 9 of FIG. 8 , illustrating various cross-sectional configurations and characteristics of various embodiments of grooves in accordance with the present invention;
[0040] FIG. 17 is an exploded perspective view of a calendaring apparatus for manufacturing stents in accordance with the present invention;
[0041] FIG. 18 is a partial cross-sectional view of a stamping apparatus for manufacturing stents in accordance with the present invention, looking down the longitudal axis of a mandrel;
[0042] FIG. 19 is an exploded perspective view of an apparatus utilizing an impression roller to manufacturer stents in accordance with the present invention;
[0043] FIG. 20 is an exploded perspective view of an expanding mandrel apparatus for manufacturing stents in accordance with the present invention;
[0044] FIG. 21 is a partial cross-sectional view of the mandrel of FIG. 20 , taken along lines 21 - 21 of FIG. 20 ;
[0045] FIG. 22 is an exploded perspective view of an apparatus utilizing a tapered mandrel to manufacture stents in accordance with the present invention;
[0046] FIG. 23 is an exploded perspective view of an apparatus utilizing a chemical removal method to manufacture stents in accordance with the present invention;
[0047] FIG. 23A is a partial cross-sectional exploded view of a portion of FIG. 23 ;
[0048] FIG. 23B is a partial cross-sectional exploded view of a portion of FIG. 23 ;
[0049] FIG. 24A is an exploded perspective view of an apparatus utilizing a rotating coaxial light source to inscribe microgrooves inside an intact tubular stent in accordance with the present invention;
[0050] FIG. 24B is an exploded perspective view of an apparatus utilizing a rotating mask and fixed light source to inscribe microgrooves inside an intact tubular stent in accordance with the present invention; and
[0051] FIG. 25 is an exploded perspective view of an electric discharge machining apparatus for manufacturing stents in accordance with the present invention.
[0052] FIGS. 26-33 are various embodiments of an exploded view of a groove taken along line 9 - 9 of FIG. 8 , illustrating various cross-sectional configurations and characteristics of various embodiments of grooves having a drug eluting polymer disposed within the groove in accordance with the present invention
[0053] While the invention will be described in connection with the preferred embodiment, it will be understood that it is not intended to limit the invention of that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
[0054] With reference to FIGS. 1 and 2 , an intravascular stent 200 is illustrated being disposed within an artery 290 in engagement with arterial wall 210 . For illustrative purposes only, intravascular stent 200 , shown in FIGS. 1-6 is a Palmaz™ balloon-expandable stent, as is known in the art, stent 200 having an inner surface 201 and an outer surface 202 . FIGS. 1 and 2 illustrate stent 200 shortly after it has been placed within artery 290 , and after stent 200 has been embedded into arterial wall 210 , as is known in the art. FIGS. 1 and 2 illustrate what may be generally characterized as correct placement of an intravascular stent. Stent 200 preferably includes a plurality of metal members, or struts, 203 , which may be manufactured of stainless steel, or other metal materials, as is known in the art. As illustrated in FIGS. 1 and 2 , correct placement of stent 200 results in tissue mounds 211 protruding between the struts 203 , after struts 203 have been embedded in the arterial wall 210 . Struts 203 also form troughs, or linear depressions, 204 in arterial wall 210 . Dependent upon the degree of blockage of artery 290 , and the type and amount of instrumentation utilized prior to placement of stent 200 , the mounds of tissue 211 may retain endothelial cells (not shown).
[0055] With reference to FIGS. 3 and 4 , after the passage of time, a thin layer of thrombus 215 rapidly fills the depressions 204 , and covers the inner surfaces 201 of stent 200 . As seen in FIG. 4 , the edges 216 of thrombus 215 feather toward the tissue mounds 211 protruding between the struts 203 . The endothelial cells which were retained on tissue mounds 211 can provide for reendothelialization of arterial wall 210 .
[0056] With reference to FIGS. 5 and 6 , endothelial regeneration of artery wall 210 proceeds in a multicentric fashion, as illustrated by arrows 217 , with the endothelial cells migrating to, and over, the struts 203 of stent 200 covered by thrombus 215 . Assuming that the stent 200 has been properly implanted, or placed, as illustrated in FIGS. 1 and 2 , the satisfactory, rapid endothelialization results in a thin tissue layer 218 , as shown in FIG. 7 . As is known in the art, to attain proper placement, or embedding, of stent 200 , stent 200 must be slightly overexpanded. In the case of stent 200 , which is a balloon-expandable stent, the balloon diameter chosen for the final expansion of stent 200 must be 10% to 15% larger than the matched diameter of the artery, or vessel, adjacent the site of implantation. As shown in FIG. 7 , the diameter Di of the lumen 219 of artery 290 is satisfactory. If the reendothelialization of artery wall 210 is impaired by underexpansion of the stent or by excessive denudation of the arterial wall prior to, or during, stent placement, slower reendothelialization occurs. This results in increased thrombus deposition, proliferation of muscle cells, and a decreased luminal diameter Di, due to the formation of a thicker neointimal layer.
[0057] With reference to FIG. 8 , an intravascular stent 300 in accordance with the present invention is illustrated. For illustrative purposes only, the structure of intravascular stent 300 is illustrated as being a PALMAZ balloon-expandable stent, as is known in the art, illustrated in its initial, unexpanded configuration. It should be understood that the improvement of the present invention is believed to be suitable for use with any intravascular stent having any construction or made of any material as will be hereinafter described. Similarly, the improvement of the present invention in methods for manufacturing intravascular stents, is also believed to be applicable to the manufacturing of any type of intravascular stent as will also be hereinafter described.
[0058] As illustrated in FIG. 8 , intravascular stent, or stent, 300 has an inner surface 301 , and an outer surface 302 , outer surface 302 normally being embedded into arterial wall 210 in an abutting relationship. In accordance with the present invention, the inner surface 301 of stent 300 is provided with at least one groove 400 . If desired, as will be hereinafter described in greater detail, a plurality of grooves 400 could be provided on, or in, inner surface 301 of stent 300 . The at least one groove 400 , or grooves, of the present invention may be provided in, or on, the inner surface 301 of stent 300 in any suitable manner, such as by: abrading the inner surface 301 of stent 300 to provide the at least one groove 400 ; a chemical or mechanical etching process; use of a laser or laser etching process; use of a diamond-tipped tool; use of any suitable abrasive material; or use of any tool or process, which can provide the desired groove, or grooves, 400 in, or on, the inner surface 301 of stent 300 , as will be hereinafter described in greater detail.
[0059] As shown in FIG. 8 , the at least one groove, or grooves, 400 may be disposed with its longitudinal axis 410 being disposed substantially parallel with the longitudinal axis 305 of stent 300 . Alternatively, the longitudinal axis 410 of the at least one groove 400 may be disposed substantially perpendicular to the longitudinal axis 305 of stent 300 , as illustrated by groove 400 ″″; or the longitudinal axis 410 of the groove may be disposed at an obtuse, or acute, angle with respect to the longitudinal axis 305 of stent 300 , as illustrated by groove 400 ′. The angle that groove 400 ′ makes with respect to longitudinal axis 305 is either an acute or an obtuse angle dependent upon from which direction the angle is measured with respect to the longitudinal axis 305 of stent 300 . For example, if the angle between the longitudinal axis of groove 400 ′ and longitudinal axis 305 is measured as indicated by arrows A, the angle is an acute angle. If the angle is measured, as at arrows B, the angle is an obtuse angle.
[0060] Still with reference to FIG. 8 , a plurality of grooves 400 may be provided on the inner surface 301 of stent 300 , two grooves 400 being shown for illustrative purposes only. Instead of a plurality of individual grooves, such as grooves 400 , a single groove 400 ″ could be provided in a serpentine fashion, so as to cover as much of the inner surface 301 of stent 300 as desired. Similarly, the grooves could be provided in a cross-hatched manner, or pattern, as shown by grooves 400 ′″. Grooves 400 , 400 ′, 400 ″, 400 ′″, and 400 ″″ could be provided alone or in combination with each other, as desired, to provide whatever pattern of grooves is desired, including a symmetrical, or an asymmetrical, pattern of grooves. It should be noted that the angular disposition and location of the various grooves 400 - 400 ″″ will vary and be altered upon the expansion of stent 300 within artery 201 ( FIG. 1 ), stent 300 being illustrated in its unexpanded configuration in FIG. 8 . Similarly, if stent 300 were a stent made of wire or lengths of wire, the disposition and angular orientation of the grooves formed on such wire, or wire members, would similarly be altered upon the expansion and implantation of such stent. It should be further noted, as previously discussed, that the groove, or grooves, may be provided in, or on, the inner surface of any intravascular stent, so as to increase the rate of migration of endothelial cells on, and over, the inner surface of the intravascular stent.
[0061] With reference to FIGS. 9-16 , various embodiments of groove 400 will be described in greater detail. In general, as seen in FIG. 9 , groove 400 has a width W, a depth D, and a length L ( FIG. 8 ). The width W and depth D may be the same, and not vary, along the length L of the groove 400 . Alternatively, the width W of the groove may vary along the length L of the groove 400 . Alternatively, the depth D of the groove may vary along the length L of the at least one groove. Alternatively, both the width W and the depth D of the groove 400 may vary along the length of the at least one groove. Similarly, as with the location and angular disposition of groove, or grooves, 400 as described in connection with FIG. 8 , the width W, depth D, and length L of the groove, or grooves, 400 can vary as desired, and different types and patterns of grooves 400 could be disposed on the inner surface 301 of stent 300 .
[0062] As shown in FIGS. 9-16 , groove 400 may have a variety of different cross-sectional configurations. As desired, the cross-sectional configuration of the groove, or grooves, 400 may vary along the length L of the groove; or the cross-sectional configuration of the groove may not vary along the length of the at least one groove 400 . Similarly, combinations of such cross-sectional configurations for the grooves could be utilized. The cross-sectional configuration of the groove, or grooves, 400 may be substantially symmetrical about the longitudinal axis 410 of groove 400 as illustrated in FIGS. 8 and 9 ; or the cross-sectional configuration of the at least one groove may be substantially asymmetrical about the longitudinal axis 410 of the least one groove, as illustrated in FIGS. 14 and 16 . The cross-sectional configurations of groove 400 can assume a variety of shapes, some of which are illustrated in FIGS. 9-16 , and include those cross-sectional configurations which are substantially: square shaped ( FIG. 9 ); U shaped ( FIG. 10 ); triangular, or V shaped ( FIG. 1 ); rectangular shaped ( FIG. 12 ); and triangular, or keyway shaped ( FIG. 13 ). The wall surface 303 of each groove 400 may be substantially smooth, such as illustrated in FIGS. 9-13 , or wall surface 303 may be jagged, or roughened, as illustrated in FIGS. 14 and 16 . As illustrated in FIG. 15 , wall surface 303 could also be provided with at least one protrusion 304 and at least one indentation 305 if desired, and additional protrusions and indentations 304 , 305 could be provided as desired.
[0063] The depth D of groove, or grooves, 400 may fall within a range of approximately one-half to approximately ten microns. The width W of groove, or grooves, 400 , may fall within a range of approximately two to approximately forty microns. Of course, the width W and depth D could be varied from the foregoing ranges, provided the rate of migration of endothelial cells onto stent 300 is not impaired. The length L of groove 400 may extend the entire length of stent 300 , such as groove 400 of FIG. 8 ; or the length L′ of a groove may be less than the entire length of stent 300 , such as groove 400 ″″ in FIG. 8 . The groove, or grooves, of the present invention may be continuous, or discontinuous, along inner surface 301 of stent 300 . Further, in some embodiments, a land area 310 between adjacent grooves, such as grooves 400 ″″ in FIG. 8 , may have a width substantially equal to the width of the adjacent grooves.
[0064] The portion of the inner surface 301 of stent 300 which has not been provided with a groove, or grooves, 400 in accordance with the present invention, may have any suitable, or desired, surface finish, such as an electropolished surface, as is known in the art, or may be provided with whatever surface finish or coating is desired. It is believed that when at least one groove in accordance with the present invention is disposed, or provided, on, or in, the inner surface 301 of an intravascular stent 300 , after the implantation of stent 300 , the rate of migration of endothelial cells upon the inner surface 301 of stent 300 will be increased over that rate of migration which would be obtained if the inner surface 301 were not provided with at least one groove in accordance with the present invention.
[0065] To manufacture intravascular stents with at least one groove disposed in the inner surface of the stent, the current best technology for inscribing microgrooves on metals seems to be photoetching. The present invention provides improved methods of inscribing the grooved pattern inside an intact tubular stent.
[0066] With reference to FIG. 17 , a calendaring apparatus 450 is illustrated forming at least one groove 400 (not shown) on, or in, the inner surface 301 of stent blank 300 . Calendaring apparatus 450 includes at least one calendaring roller 451 and an inner mandrel 452 . Calendaring roller 451 is provided with a bearing shaft 453 and a pinion gear 454 , which is driven by a gear drive 455 and gear drive apparatus 456 . Bearing shaft 453 is received in a bearing block 457 , which has a groove 458 for receipt of bearing shaft 453 . Bearing block 457 also includes a bottom plate 459 and bearing block 457 is movable therein, in the direction shown by arrows 460 , as by slidably mating with slots 461 formed in bottom plate 459 . Bearing block 457 is further provided with an opening, or bearing journal, 465 for rotatably receiving mounting hub 466 disposed upon the end of mandrel 452 . Calendaring roller is rotated in the direction shown by arrow 467 and bears against the outer surface 302 of stent blank 300 , with a force sufficient to impart the groove pattern 468 formed on the outer surface of mandrel 452 to the inner surface 301 of stent blank 300 . Mandrel 452 will have a raised groove pattern 468 on the outer surface of mandrel 452 , corresponding to the desired groove, or grooves, 400 to be formed on, or in, the inner surface 301 of stent 300 . The raised groove pattern 468 of mandrel 452 must be hardened sufficiently to enable the formation of many stents 300 without dulling the groove pattern 468 of mandrel 452 . Mandrel 452 may have a working length corresponding to the length of the stent 300 and an overall length longer than its working length, to permit the receipt of mandrel mounting hub 466 within bearing block 457 and mounting hub 466 within gear drive apparatus 456 .
[0067] Still with reference to FIG. 17 , the outer diameter of mandrel 452 is preferably equal to the inner diameter of the stent 300 in its collapsed state. The groove pattern 468 may correspond to the desired groove pattern of groove, or grooves, 400 to be formed on the inner surface 301 of stent 300 after stent 300 has been fully expanded. If the desired groove pattern upon expansion of stent 300 is to have the groove, or grooves 400 become parallel to each other upon expansion of the stent 300 , along the longitudal axis of the expanded stent 300 , groove pattern 468 , or the pre-expanded groove pattern, must have an orientation to obtain the desired post expansion groove pattern, after radial expansion of stent 300 . Stent 300 may be pre-expanded slightly to facilitate its placement on the mandrel 452 in order to prevent scratching of the stent 300 . Mandrel 452 may include an orientation mechanism, or pin 469 which mates with a corresponding notch 469 ′ on stent blank 300 , in order to insure proper orientation of stent blank 300 with respect to mandrel 452 . Stent 300 may be crimped circumferentially around mandrel 452 after it has been properly oriented. The force to impart the desired groove pattern 468 upon, or in, the inner surface 301 of stent 300 is provided by calendaring roller 451 .
[0068] With reference to FIG. 18 , an alternative structure is provided to impart the desired groove pattern in, or upon, the inner surface 301 of stent blank 300 . In lieu of calendaring roller 451 , a punch press, or stamping apparatus, 470 may be utilized to force the inner surface 301 of stent 300 upon the groove pattern 468 of mandrel 452 . Stamping apparatus 470 may include a hydraulic cylinder 471 and hydraulic piston 472 , attached to a stamping segment 473 . The inner surface 474 of stamping segment 473 has a radius of curvature which matches the outer radius of curvature 475 of stent 300 , when it is disposed upon mandrel 452 . If desired, a plurality of stamping devices 470 ′ may be disposed about the outer surface 302 of stent 300 , or alternatively a single stamping device 470 may be utilized, and stent 300 and mandrel 452 may be rotated to orient the stent 300 beneath the stamping segment 473 .
[0069] With reference to FIG. 19 , the desired grooves 400 may be formed on the inner surface 301 of stent blank 300 by an impression roller 480 which serves as the inner mandrel. Impression roller 480 is supported at its ends by roller bearing block 481 , similar in construction to previously described bearing block 457 . Similarly, a gear drive, or drive gear mechanism, 482 may be provided, which is also similar in construction to gear drive 455 . Impression roller 480 has a bearing shaft 483 at one end of impression roller 480 , bearing shaft 483 being received by an opening, or journal bearing, 484 in bearing block 481 . The other end of impression roller 480 may have a pinion gear 485 which is received within rotating ring gear 486 in gear drive mechanism 482 . A backup housing, such as a two-part backup housing 487 , 487 ′ may be provided for fixedly securing stent blank 300 while impression roller 480 is rotated within stent blank 300 to impart groove pattern 468 formed on the exterior of impression roller 480 to the inner surface 301 of stent blank 300 .
[0070] With reference to FIGS. 20 and 21 , an expanding mandrel apparatus 500 for forming the desired at least one groove 400 on, or in, the inner surface 301 of stent blank 300 is illustrated. Expanding mandrel 501 is preferably formed of a plurality of mating and tapered segments 502 having the desired groove pattern 468 formed on the outer surface 503 of each segment 502 . Stent blank 300 is disposed upon expanding mandrel 501 in the unexpanded configuration of expanding mandrel 501 , stent blank 300 being oriented with respect to mandrel 501 , as by the previously described notch 469 ′ and pin 469 . A backup housing 487 and 487 ′, as previously described in connection with FIG. 19 , may be utilized to retain stent blank 300 while expanding mandrel 501 is expanded outwardly to impart the desired groove pattern 468 upon, or in, the inner surface 301 of stent blank 300 . In this regard, expanding mandrel 501 is provided with a tapered interior piston 505 , which upon movement in the direction of arrow 506 forces mandrel segments 502 outwardly to assume their desired expanded configuration, which forces groove pattern 468 on mandrel 501 against the inner surface 301 of stent blank 300 . O-rings 507 may be utilized to secure stent 300 upon mandrel 501 .
[0071] With reference to FIG. 22 , a tapered mandrel groove forming apparatus 530 is illustrated. Tapered mandrel 531 is supported by a mandrel support bracket, or other suitable structure, 532 to fixedly secure tapered mandrel 531 as shown in FIG. 22 . The end 533 of tapered mandrel 531 , has a plurality of cutting teeth 534 disposed thereon. The cutting teeth 534 may be abrasive particles, such as diamond chips, or tungsten carbide particles or chips, which are secured to tapered mandrel 531 in any suitable manner, and the cutting teeth 534 form the desired groove, or grooves, 400 on, or in, the inner surface 301 of stent blank 300 . Alternatively, instead of cutting teeth 534 , the outer surface 535 of tapered mandrel 531 could be provided with a surface comparable to that formed on a metal cutting file or rasp, and the file, or rasp, profile would form the desired grooves 400 . A stent holding fixture 537 is provided to support stent blank 300 in any desired manner, and the stent holding fixture 367 may be provided with a piston cylinder mechanism, 368 , 369 to provide relative movement of stent 300 with respect to tapered mandrel 531 . Alternatively, stent 300 can be fixed, and a suitable mechanism can be provided to move tapered mandrel 531 into and along the inner surface 301 of stent 300 . Preferably, stent 300 is in its expanded configuration.
[0072] With reference to FIGS. 23, 23A and 23B , a chemical removal technique and apparatus 600 for forming the desired groove, or grooves, 400 on, or in, the interior surface 301 of stent blank 300 is illustrated. A stent holding fixture 601 is provided, and holding fixture 601 may be similar in construction to that of stent holding fixture 367 of FIG. 22 . Again, stent blank 300 is provided with an orientation notch, or locator slot, 469 ′. A photo mask 602 is formed from a material such as Mylar film. The dimensions of the mask, 602 correspond to the inner surface area of the inner surface 301 of stent 300 . The mask 602 is formed into a cylindrical orientation to form a mask sleeve 603 , which is wrapped onto a deflated balloon 605 , such as a balloon of a conventional balloon angioplasty catheter. A conventional photoresist material is spin coated onto the inner surface 301 of stent blank 300 . The mask sleeve 603 , disposed upon balloon 605 is inserted into stent 300 , and balloon 605 is expanded to force the mask sleeve 603 into an abutting relationship with the photoresist coated inner surface 301 of stent 300 . Balloon 605 may be provided with an orientation pin 606 which corresponds with an orientation notch 607 on mask sleeve 603 , which in turn is also aligned with locator slot 469 ′ on stent blank 300 . The expansion of balloon 605 is sufficient to sandwich mask sleeve 603 into abutting contact with the photoresist coated inner surface 301 of stent 300 ; however, the balloon 605 is not inflated enough to squeeze the photoresist material off the stent 300 . The interior surface 301 of stent 300 is then irradiated through the inside of the balloon 605 through the balloon wall, as by a suitable light source 610 . Balloon 605 is then deflated and mask sleeve 603 is removed from the interior of stent 300 . The non-polymerized photoresist material is rinsed off and the polymerized resist material is hard baked upon the interior of stent 300 . The groove, or grooves 400 are then chemically etched into the non-protected metal surface on the interior surface 301 of stent 300 . The baked photoresist material is then removed by either conventional chemical or mechanical techniques.
[0073] Alternatively, instead of using a Mylar sheet as a mask 602 to form mask sleeve 603 , mask 602 may be formed directly upon the outer surface of balloon 605 , as shown in FIG. 23A . The production of mask 602 directly upon the balloon outer surface can be accomplished by physically adhering the mask 602 onto the outer surface of balloon 605 , or by forming the mask 602 onto the surface of balloon 605 by deposition of the desired groove pattern 468 by deposition of UV absorbing material by thin film methods. In the case of utilizing mask sleeve 603 as shown in FIG. 23B , the balloon material must be compliant enough so as to prevent creases from the balloon wall which may shadow the resulting mask 602 . In the case of mask 602 being formed on balloon 605 as shown in FIG. 23A , a non-compliant balloon 605 should be used, so as not to distort the resulting image by the stretching of the compliant balloon wall. If on the other hand, the mask 602 is physically adhered to the outer wall of balloon 605 , a compliant balloon 605 may be used provided the mask 602 is adhered to the balloon 605 when the balloon 605 is in its fully expanded diameter.
[0074] With reference to FIGS. 24A and 24B , a method is shown for creating grooves inside an intact tubular stent 300 , which involves casting patterned light inside a stent 300 previously coated with photosensitive material as discussed, for example, in connection with FIG. 23 (PSM). The light exposed areas are subjected to chemical etching to produce the grooved pattern. This method involves using a coaxial light source 800 with multiple small beams 801 of light in a single plane. The light source 800 could be displaced along the longitudinal axis of the tube, or stent 300 , at a rate consistent with adequate exposure of the photosensitive material. Computer driven stepper motors could be utilized to drive the light source in the x and y planes, which would allow for interlacing grooves (see FIG. 24A ). One pass could create 1 mm spacing, while the next pass creates 500 μm, and so on.
[0075] Rotational movements could introduce variability in the groove direction for zig-zag, spiral or undulating patterns. Alternatively, the light source 800 could be fixed as shown in FIG. 24B , and the beams would be as narrow and long as the grooves needed on the inner surface of the mask 602 . Stepping of the mask 602 would allow narrow spacing of the grooves.
[0076] With reference to FIG. 25 , an EDM process and apparatus 700 provide the desired groove, or grooves, 400 upon the interior 301 of stent 300 . A non-conductive stent alignment and holding fixture 701 , 701 ′, similar in construction to backup housings 487 , 487 ′, previously described, are provided for holding stent like blank 300 . A bearing block assembly 702 , similar to bearing block assembly 481 of FIG. 19 , is provided along with an indexing and current transfer disk 703 provided within a drive gear mechanism 704 , which is similar in construction to drive gear mechanisms 482 and 455 , previously described in connection with FIGS. 19 and 17 . An electric discharge machining (“EDM”) electrode 710 having bearing shafts 711 , 712 , disposed at its ends, for cooperation with bearing block assembly 702 and disk 703 , respectively, is rotated within stent blank 300 . Current is provided to the raised surfaces, or groove pattern, 468 , of electrode 710 to cut the desired groove, or grooves 400 into the inner surface 301 of stent 300 .
[0077] Finally, turning to FIGS. 26-33 there is illustrate the another embodiment of the present invention which includes a polymer-filled groove 800 . Like the foregoing described embodiments of the at least one groove 400 described with reference to FIGS. 9-16 , the polymer-filled groove 800 may have a variety of different cross-sectional configurations. As desired, the cross-sectional configuration of the groove, or grooves, 800 may vary along the length L of the groove; or the cross-sectional configuration of the groove may not vary along the length of the at least one groove 800 . Similarly, combinations of such cross-sectional configurations for the grooves could be utilized. The cross-sectional configuration of the groove, or grooves, 800 may be substantially symmetrical about the longitudinal axis of groove 800 ; or the cross-sectional configuration of the at least one groove may be substantially asymmetrical about the longitudinal axis of the least one groove. The cross-sectional configurations of groove 400 can assume a variety of shapes, some of which are illustrated in FIGS. 26-33 , and include those cross-sectional configurations which are substantially: square shaped ( FIG. 26 ); U shaped ( FIG. 27 ); triangular, or V shaped ( FIG. 28 ); rectangular shaped ( FIG. 29 ); and truncated triangular, or keyway shaped ( FIG. 30 ). The wall surface 303 of each groove 800 may be substantially smooth, such as illustrated in FIGS. 26-30 , or wall surface 303 may be jagged, or roughened, as illustrated in FIGS. 31 and 33 . As illustrated in FIG. 32 , wall surface 303 could also be provided with at least one protrusion 304 and at least one indentation 305 if desired, and additional protrusions and indentations 304 , 305 could be provided as desired.
[0078] The depth D of groove, or grooves, 800 may fall within a range of approximately one-half to approximately ten microns. The width W of groove, or grooves, 800 , may fall within a range of approximately two to approximately forty microns. Of course, the width W and depth D could be varied from the foregoing ranges, provided the rate of migration of endothelial cells onto stent 300 is not impaired. The length L of groove 800 may extend the entire length of stent 300 , such as groove 400 of FIG. 8 ; or the length L′ of a groove 800 may be less than the entire length of stent 300 , such as groove 400 ′″″ in FIG. 8 . The groove, or grooves, of the present invention may be continuous, or discontinuous, along inner surface 301 of stent 300 .
[0079] A biocompatible polymer 810 is disposed within at least a portion of groove 800 , and more preferably at least a substantial portion of groove 800 . Biocompatible polymer 810 is of the type capable of eluting bioactive agents. Specific bioactive agent eluting polymers are well known in the art and are hereby incorporated by reference.
[0080] The biocompatible polymer 810 is present only in the groove 800 and not otherwise on either the inner surface 301 or the outer surface 302 of the stent 300 . As discussed above, the portion of the inner surface 301 or outer surface 302 of stent 300 which has not been provided with a groove, or grooves, 800 , and therefore does not have polymer 810 thereupon, may have any suitable, or desired, surface finish, such as an electropolished surface, as is known in the art, or may be provided with whatever surface finish or coating is desired. It has been found that when at least one groove in accordance with the present invention is disposed, or provided, on, or in, the inner surface 301 of an intravascular stent 300 , after the implantation of stent 300 , the rate of attachment, migration and proliferation of endothelial cells upon the inner surface 301 of stent 300 is increased over that rate of attachment, migration and proliferation observed in stents that do not have the at least one groove in accordance with the present invention.
[0081] Table 1, below, summarizes the migration distance of endothelial cells onto metal, polymer and hybrid metal-polymer coupon surfaces both with and without grooves in accordance with the present invention. The tests reflected in Table 1 were conducted by preparing metal coupon samples which were 1 cm square of either. All coupon samples are 1 cm square 316L Stainless steel or L605 Cobalt-Chrome with exposed metal surfaces electropolished and passivated. Coupon thickness was between about 0.020″-0.025″. Parylene C was coated onto the coupons by chemical vapor deposition to a thickness between 2-3 microns. Groove dimensions were 12 microns in width and 3 microns in depth with 12 micron spacing between adjacent grooves. Three replicates of each sample type were used.
[0082] The metal only coupons were cute using wire electrical discharge machining (EDM), mechanically polished, then electropolished, passivated in acid and then cleaned and packaged. The parylene C coated coupons were cut from a sheet of metal, coated with parylene C and then cleaned and packaged. The Parylene C coated, grooved coupons were cut from a metal sheet, mechanically polished, grooves were formed by laser ablation and then the entire surface, including the groove pattern was coated with Parylene C as noted above, the coated coupon was then cleaned and packaged. The Parylene C coated coupon with an exterior surface having metal grooves was prepared by cutting the coupons from a metal sheet, mechanically polishing, followed by coating with Parylene C as described above, then forming a groove pattern by laser ablation through the Parylene coating and into the metal coupon, then electropolishing to a final groove depth, followed by passivating the exposed metal, neutralizing the passivation, cleaning and packaging the coupons. Finally, the coupons having Parylene filled grooves with an exposed exterior metal surface were prepared by cutting the coupons from a metal sheet, mechanically polishing the coupon, laser ablating the groove pattern into the metal coupon, then coating the coupon with Parylene, mechanically polishing or planarizing the grooved surface to expose the metal land areas between adjacent grooves, ultrasonically cleaning the coupon, electropolishing the exposed metal, passivating the exposed metal, neutralizing the passivating acid, cleaning and packaging the coupon.
[0000]
TABLE 1
Endothelial Cell
Sample
Migration Distance
No.
Material Description
(mm/10 days)
1a
316 L Stainless Steel-Electropolished and ungrooved
1.75 ± 0.25
2a
316 L Stainless Steel-Parylene C Coated and ungrooved
0.167 ± 0.14
3a
316 L Stainless Steel-Grooved and Parylene C Coated
1.68 ± 0.38
4a
316 L Stainless Steel-Parylene C Coated and Grooved
4.93 ± 0.1
through Parylene to expose metal
5a
316 L Stainless Steel-Grooved and Parylene C filling
5.0 ± 0.0
the grooves with exposed metal lands between grooves
1
CoCr L605-Electropolished and ungrooved
1.125 ± 0.11
2
CoCr L605-Parylene C Coated and ungrooved
0.1 ± 0.0
3
CoCr L605-Parylene C Coated and Grooved through
5.0 ± 0.0
Parylene to expose metal
4
CoCr L605-Grooved and Parylene C filling the grooves
3.95 ± 0.16
with exposed metal lands between grooves
[0083] As will be understood from Table 1, both the Parylene filled metal grooves and the Parylene covered landing regions between exposed metal grooves exhibited significantly greater endothelial cell migration when compared to a bare metal surface, an ungrooved Parylene coated metal surface or a grooved Parylene coated metal surface without metal exposed.
[0084] It is to be understood that the invention is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as obvious modifications and equivalents will be apparent to one skilled in the art. Accordingly, the invention is therefore to be limited only by the scope of the appended claims.
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The invention relates to methods and apparatus for manufacturing implantable medical devices, such as intravascular stents, wherein the medical device has a surface treated to promote the migration of endothelial cells onto the surface of the medical device. In particular, the surface of the medical device has at least one groove formed therein, the at least one groove may have a drug-eluting polymer disposed therein or a drug-eluting polymer coating may be provided on the surface of the medical device and grooves formed in the drug eluting polymer coating.
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BACKGROUND OF THE INVENTION
Various configurations of electric cartridge heaters are known in the prior art. A typical cartridge heater includes a metal sheath around a resistance-wire heating element coiled around a core of insulating material. An insulating filler material with appropriate thermal conductivity and electrical insulating properties is used to fill the space between the coil and the sheath. Granulated magnesium oxide is typically used as the insulating filler material. After the sheath is filled, the sheath is subjected to compression forces, for example, by swaging. Compression compacts the granulated magnesium oxide and improves its dielectric and thermal conductivity properties. Lead wires may be attached to the coil before or after filling the sheath and may be held in place with an end plug made of materials such as Teflon, mica and silicone rubber. The lead wires become secured within the plug after swaging. The lead wires may then be potted with sealants to provide moisture resistance. Depending upon the intended application, cartridge heaters of varying sizes and voltage ratings may be required. U.S. Pat. No. 6,172,345, for example, discloses a high voltage cartridge heater which includes a core sleeve of pre-compacted insulating material.
With current manufacturing technology, it has proven to be a challenge to reliably produce high-voltage cartridge heaters for high moisture environments. Heaters in operation in high moisture environments are prone to dielectric breakdown and current leakage problems caused by the egress of moisture and water into the dielectric insulating material. In high moisture environments, dielectric integrity and current leakage must be kept within predetermined limits in order for the cartridge to meet certain industry standards, such as those standards established by Underwriters Laboratories, for example, the UL 471 standards.
One apparent reason for such problems is that the potting sealants and sealant methods used to seal the lead wire end of the cartridge do not provide adequate bonding with the lead wires and the sheath. Sealant materials, such as epoxy and silicone, for example, do not bond adequately with the stainless steel used for the construction of the sheath or with the silicone-coated lead wires. As a result, high-voltage cartridge heaters are traditionally only offered with sealants that do not qualify for certification for high moisture environments under the applicable industry standards.
SUMMARY
One embodiment of the invention provides a cartridge heater. The cartridge includes a sheath having a first end and a second end. The first end of the sheath forms a seat. An elastomeric bushing is swaged against the seat such that it forms a mechanically bonded seal substantially preventing moisture egress into the cartridge heater. A heating element is also disposed in the sheath and is connected to leads protruding from the bushing. The heater may include crushable insulation material disposed within the sheath.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying Figures, there are shown present embodiments of the invention wherein like reference numerals are employed to designate like parts and wherein:
FIG. 1 is a sectional view of an embodiment of cartridge heater according to the present invention;
FIG. 2 a is a rear view of an embodiment of a sheath for the cartridge heater of FIG. 1;
FIG. 2 b is a side view of the sheath of FIG. 2 a;
FIG. 2 c is a front view of the sheath of FIG. 2 a;
FIG. 3 a is a side view of one embodiment of a seal bushing for the cartridge heater of FIG. 1; and
FIG. 3 b is a side view of one embodiment of a seal bushing for the cartridge heater of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings for the purpose of illustrating the invention and not for the purpose of limiting the same, it is to be understood that standard components or features that are within the purview of an artisan of ordinary skill and do not contribute to the understanding of the various embodiments of the invention are omitted from the drawings to enhance clarity. In addition, it will be appreciated that the characterizations of various components and orientations described herein as being “vertical” or “horizontal”, “right” or “left”, “side”, “top” or “bottom”, are relative characterizations only based upon the particular position or orientation of a given component for a particular application.
FIG. 1 shows a side cross-sectional view of a cartridge heater 10 in accordance with one embodiment of the invention. In the embodiment of FIG. 1, the heater 10 may include an elongate heater element wind core 12 about which a resistive heating element wire 14 may be coiled, in an essentially conventional configuration. The wind core 12 may be made of magnesium oxide, and is substantially cylindrical. The wind core 12 and the coiled wire 14 are disposed within an outer sheath 16 made of, for example, stainless steel or the like. Interposed between the inner diameter of the sheath 16 and the heating element 14 is an electrically insulating, thermally conducting material 18 (hereinafter “insulating material”). The insulating material 18 may be composed of loose-fill or pre-compacted magnesium oxide.
The sheath 16 may be a tube that has a first end 32 and a second end 34 . An annular seat 26 is formed at the second end 34 of the sheath 16 prior to assembly by spin over or other conventional forming means. See FIGS. 2 a - 2 c . The seat 26 extends from the second end 34 of the sheath 16 and is curved 90° relative to the sheath 16 through a curved portion 27 to form an annular planar surface 29 . The inner radius of the curved portion 27 of the seat 26 may be, for example, {fraction (1/32)} of an inch and the outer radius {fraction (1/16)} of an inch. The corresponding thickness of the sheath may be 0.028 inches.
Operating power is supplied to cartridge heater 10 by means of two supply (lead) wires 20 . The wires 20 may 18-gauge, silicone rubber-coated wire rated to conduct on the order of 600 volts. The wires 20 enter the second end 34 of heater 10 through a seal bushing 22 and a mica disk 24 each having appropriately sized through-holes formed therein. The seal bushing 22 may be made of elastomeric or rubber-like material. For example, a fluorocarbon elastomer, such as the commercially available Viton® with Shore A durometer in the range of 70-80 may be used. A nitrile elastomer, such as BUNA N with Shore A durometer in the range of 65-75 may be also used. The seal bushing 22 may have a rounded edge 38 conforming to the curved portion 27 of the seat 34 , as shown in FIGS. 1 and 3 a, or it may have straight edges as shown in FIG. 3 b.
In the embodiment of FIG. 1, the sheath 16 may be approximately four inches long, and may have an outer diameter of one-half inch or less. The core 14 may have a length of approximately three and one half inches. The seal bushing 22 has a diameter which is equal to the inner diameter of the sheath 16 before swaging, approximately {fraction (7/16)} of an inch. The axial dimension (length) of the seal bushing may be approximately half an inch or less.
The cartridge heater 10 may assembled as follows: The sheath 16 is cut to length with allowance for the material that will become the seat 26 . The seat 26 is mechanically formed in the sheath 16 by conventional methods such as spin over, lathe machining, peening, or die forming, etc. The various components of the heater 10 are inserted into the sheath 16 from its second end 34 . Once all of the components are assembled within sheath 16 , granular magnesium oxide is introduced into the second end 34 of sheath 16 , in order to fill all remaining voids therein to the extent possible. Next, an end cap 30 is welded over the second end 34 . Finally, the entire assembly is swaged, for example at a pressure of approximately 200,000 lbs per linear inch, to compress and reduce the overall diameter of the sheath 16 . This swaging process compacts the magnesium oxide, thereby enhancing the dielectric and thermal conductive properties of the heater 10 . Swaging also compresses the radius of the seal bushing 22 and compresses the seal bushing 22 into the formed seat 26 .
The swaged seal bushing 22 forms a mechanical bond with the seat 26 and the lead wires 20 such that moisture is substantially prevented from entering into the cartridge heater 10 , when the heater 10 operates in moist locations. Such moisture prevention is achieved through the swaging of the elastomeric seal bushing 22 against the seat 26 without the need to use of any chemical sealants, such as epoxy, silicone or other cementing material, which could limit the versatility of the heater 10 by restricting operability of the heater at certain temperature.
Tests conducted by the independent Underwriters Laboratories (UL) showed that the heater 10 meets the standards established for Commercial Refrigerators and Freezers, UL 471, 8 th Edition for moist locations. A moist location is defined as a location in which the heater is exposed to moisture but is not subject to more than occasional contact with water in a refrigerator. The test is conducted by operating the heater for 1000 cycles at a rate of 1½ minutes on 13½ minutes off in an atmosphere of not less than 98% humidity at any convenient temperature above 0° C. (32° F.). A seal for a cartridge heater that demonstrably passes this test is defined herein as a seal that substantially prevents moisture egress into the heater. The heater 10 was also certified by UL for operation up to 190° C. temperature in the bushing. On the contrary, prior art epoxy seals are limited to 90° C. and Teflon seals are limited to temperatures of 150° C.
Whereas particular embodiments of the invention have been described herein for the purpose of illustrating the invention and not for the purpose of limiting the same, it will be appreciated by those of ordinary skill in the art that numerous variations of the details, materials and arrangement of parts may be made within the principle and scope of the invention without departing from the spirit of the invention. The preceding description, therefore, is not meant to limit the scope of the invention. Rather the scope of the invention is to be determined only by the appended claims and their equivalents.
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A cartridge heater and method of manufacturing same. In one embodiment, the cartridge includes a sheath having a first end and a second end. The first end of the sheath forms a seat. An elastomeric bushing is swaged against the seat such that it forms a mechanically bonded seal substantially preventing moisture egress into the cartridge heater. A heating element is also disposed in the sheath and is connected to leads protruding from the bushing. The heater includes crushable insulation material disposed within the sheath.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present inventions pertain to semiconductor fabrication processing. More particularly, the present inventions relate to a system and method for reducing defects during short polishes of semiconductor wafers by raising the pH of the wafer surface in the presence of abrasives.
2. Description of the Prior Art
Currently semiconductor wafers are reworked on a regular basis. Wafers are reworked when the final thickness of the wafer after the polish is too thick to send on to the next step in the line. The causes of a wafer being underpolished are tool interruptions, incorrect process recipes, improper tool setup and bad consumables.
Wafer rework recipes are typically shortened wafer polishing product recipes. Rework recipes, like polish recipes, typically include two or more linear or rotary tables that do the planarizing and a third table that does a water buff on a softer pad.
Referring now to FIGS. 1 and 2, there is shown a block diagram of a CMP machine 100 including a rotary process table and a side partial perspective view of a wafer 105 (FIG. 2 ). The CMP machine 100 is fed wafers to be polished by an arm 101 and places them onto a rotating polishing pad 102 . The polishing pad 102 is made of a resilient material and is textured, often with a plurality of predetermined grooves, to aid the polishing process. A conditioning arm 103 conditions the polishing pad. A wafer is held in place on the polishing pad 102 by the arm 101 with a predetermined amount of down force.
During polishing, the lower surface of the wafer 105 rests against the polishing pad 102 . As the polishing pad 102 rotates, the arm 101 rotates the wafer 105 at a predetermined rate. The CMP machine 100 also includes a slurry dispense tube 107 , extending across the radius of the polishing pad 102 . The slurry dispense tube 107 dispenses a flow of slurry 106 onto the polishing pad 102 from the slurry source 112 . Typically, the polishing pad 102 is primed with slurry 106 for about 8 seconds. The slurry 106 is a mixture of deionized water and polishing agents designed to aid chemically the smooth and predictable planarization of the wafer. The rotating action of both the polishing pad 102 and the wafer 105 , in conjunction with the polishing action of the slurry, combine to planarize, or polish, the wafer 105 at some nominal rate. In current systems using silica slurry the pH of the slurry is very high, typically having a pH of around 10 or 11.
After the slurry dispense process is terminated, deionized water is dispensed from the deionized water source 110 via the water dispense tube 108 onto the pad. The wafer substrate is then rid of the slurry.
Referring now to FIG. 3, there is shown a block diagram of one example of a CMP process 200 which is typically used to rework wafers having a final thickness too thick to send on to the next step in the line. Input/output station mechanism 210 is used to load and unload the wafers and to transfer the wafer to polishing platen 220 , where a high pH slurry polish is followed by an automatic rinse of deionized water, once the polish is complete. The wafer is then transferred to secondary polishing platen 230 , where a second high pH slurry polish is again followed by a deionized water rinse, when the secondary polish is complete. The wafer is then transferred to a third, softer pad, where it is buffed with deionized water. The above three platens are included on the same multiple platen CMP machine 205 . The processing that occurs on the platens defined by CMP machine 205 is referred to herein collectively as the “CMP polish processing”.
The wafer 105 may then be then unloaded manually or may be unloaded using the input station mechanism 210 . The wafer then undergoes post CMP cleaning. If desired, the wafer 105 may be transferred to brush stations 250 and/or 255 where the wafer is brushed with a scrub solution spray which, typically, has a high pH. Finally, the wafer 105 is transferred to the spin rinse and dry station 260 , where the wafer is rinsed with deionized water and then dried. The processing that occurs at the brush stations and the drying station 260 is referred to herein collectively as the “post-CMP polish processing”.
All particulate matter develops an electrically charged thin layer when suspended in a liquid solution. This charge is known as the zeta potential and can be either negative or positive. The zeta potential appears at the outer surface of the particle such that a small charge field surrounds the particle. Silica particles in a basic aqueous solution having a pH of about 10 or more results in a negative zeta potential on the silica particles. In addition, the zeta potential of any other particles present, as well as that of the surfaces contacted by the solution, is negative at such a high pH. The silica particles are thus electrostatically repelled from the semiconductor wafer facilitating the removal of the slurry residue from the wafer surface. When the pH at the surface of the wafer is lowered in the presence of silica particles, colloids form and silica agglomeration occurs on the surface of the wafer. As such, any time the pH of the wafer surface is lowered, a higher defectivity environment exists in the presence of microscopic particles. Defects generated include scratches on the wafer by slurry abrasive agglomerates and slurry abrasive (or any other particle) attaching to the wafer surface. If the pH of the liquid in contact with the wafer surface is not maintained at a high pH, the combination of downforce and abrasive particles will lead to high defects.
Three conditions are theoretically necessary to leave behind slurry residues, pits, and scratches on the wafer surfaces. First, there must be colloidal particles present on the wafer surface. These particles are the source of residual particles on the wafer surface, they are the same particles that can agglomerate and cause microscratches and oxide pit defects. Second, high downforce is necessary to overcome the energy barrier between a colloid (abrasive particle) and the wafer surface. Both electrical repulsion and Van der Waals attraction combine to create the net energy barrier between the wafer surface and the colloid. Third, in a silica based slurry system low pH reduces the electrical repulsion between the colloidal particles and makes the possibility of overcoming the energy barrier between the wafer surface and the colloidal particles more likely. Once the energy barrier is overcome, three types of destructive phenomenon can theoretically occur. First, colloidal particles begin to agglomerate. Second, colloidal particles and/or agglomerates of colloidal particles attach to the wafer surface. Third, larger agglomerates of colloidal particles scratch or pit the wafer surface, but do not adhere to the wafer surface.
Currently used short polish methods do not add defects when the polish time on each platen is greater then twenty seconds. However, when the planarization or oxide removal time on each platen decreases to less than about 15 seconds per platen, defects, especially slurry residues, become an issue. This minimum amount of total polish time forces a minimum film removal allowed for a short polish or rework. This minimum film removal is sometimes more than the final thickness specifications allow. The limitations of short polishes then, create a tradeoff between correct final wafer thickness and low post-CMP defectivity.
Referring now to FIG. 4, there is shown a first polishing platen 220 and a second polishing platen 230 , such as those of FIG. 3 . Once the slurry polish is completed on platen 220 , the wafer 410 is kept wet with deionized water until the wafer 415 on platen 230 is finished being processed. Deionized water on platen 220 is carried on the surface of wafer 410 to platen 230 . After the end-of-polish clean of wafer 415 is completed on platen 230 , the platen 230 is primed with slurry, typically for about 8 seconds, to prepare for incoming wafer 410 from platen 220 . Wafer 410 is placed on the pad. The net result is low pH at the start of the process and in the presence of abrasive. As discussed above, low pH at the wafer surface in the presence of abrasive causes agglomeration of particles, sticking of particles and agglomerates to the surface of the wafer and pitting and scratching of the wafer surface by large agglomerates. Additionally, surface uniformity is impacted. Referring now to FIG. 5, there is shown a graph of oxide removed vs. time on platen 2 and added defects vs. time on platen 2 for two platen 1 polish conditions. In the experiment used to generate FIG. 5, the two platen 1 polish conditions used were (1) the wafer dechucked on platen 1 , but having no downforce on the wafer (“the first condition”); and (2) the wafer was polished normally for 5 seconds on platen 1 (“the second condition”). FIG. 5 was generated from data acquired from wafers polished for varying times on platen 2 for the above two conditions.
Lines 510 and 512 of FIG. 5 represent the added defects vs. time on platen 2 for the first condition and for the second condition, respectively. Lines 514 and 516 represent the oxide removed vs. time on platen 2 for the first condition and for the second condition, respectively. Note that for both platen 1 conditions, defects added to the wafer peaked between 6 and 9 seconds of platen 2 polish times. Also, the data shows that the wafers must be polished for at least 15 seconds to restore defects to an acceptable level. It is believed that the defects caused early on in the platen 2 polish cycle, as shown by lines 510 and 512 of FIG. 5, are the result of interaction between the processes of platens 1 and 2 . The low pH at the surface of the wafer when first transferred from platen 1 to platen 2 makes the conditions ripe for and actually introduces defects, which must then be removed by longer time spent on platen 2 .
What is needed is a method for providing a short polish of a wafer without the defectivity issues of current wafer rework methods. What is additionally needed is a process and system for raising the pH of the wafer surface to be short polished/reworked on platen 2 prior to polishing on platen 2 .
These objects, and others, is satisfied by Applicant's present inventions disclosed herebelow.
SUMMARY OF THE INVENTION
The present inventions are directed towards a system and method of reworking a semiconductor wafer on a CMP machine ensuring for a short period of time, for example, less than 15 seconds, while improving defectivity. A high pH is maintained on the surface of the wafer when placed on a polishing pad. Additionally, in some embodiments downforce is optimized to further improve defectivity.
Related objects and advantages of the present invention will be apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
FIG. 1 is a block diagram of a prior art CMP machine.
FIG. 2 is a side partial perspective view of a semiconductor wafer.
FIG. 3 is a block diagram of one example of a typical CMP rework process system.
FIG. 4 is a block diagram of a portion of the CMP rework process system of FIG. 3 .
FIG. 5 a graph of oxide removed vs. time and of added defects vs. time for wafers being reworked on platen 2 of a system such as the system of FIG. 3 for two platen 1 polish conditions.
FIG. 6 is a flow chart of a CMP process in accordance with the present inventions.
FIG. 7 is a block diagram of a CMP polish rework system in accordance with one embodiment of the present inventions.
FIG. 8 is a graph of oxide removed vs. time and of added defects vs. time for wafers being reworked on platen 2 of a system in accordance with the embodiment of FIG. 7 .
FIG. 9 is a block diagram of a CMP polish rework system in accordance with one embodiment of the present inventions.
FIG. 10 is a graph of oxide removed vs. time and of added defects vs. time for wafers being reworked on platen 2 of a system in accordance with the embodiment of FIG. 9 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
For the purposes of promoting an understanding of the principles of the inventions, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the inventions is thereby intended, such alterations and further modifications of the principles of the inventions as illustrated therein being contemplated as would normally occur to one skilled in the art to which the inventions relate.
Referring now to FIG. 6 there is shown a flow chart of a short polish or rework process 600 that alleviates high defectivity problems typically associated with short polish or rework processes. Based on zeta potential theory and empirical data, it has been determined that to alleviate high defectivity problems for short polishes there is a need to maintain a high pH on the wafer surface after it has been exposed to a high pH slurry. If the pH of the liquid in contact with the wafer is not maintained at a high pH, the combination of downforce and abrasive particles will lead to high defects. It has been found experimentally that a wafer having a downforce of 5 psi and undergoing a short polish cycle has a defect count almost 10 times higher than a similarly prepared wafer polished at 4 psi. Additionally, in the present inventions, the term high pH is used in connection with substances having a pH of about 10 and above. More preferably, the high pH materials described herein have a pH of between about 10 and 12. In one particular embodiment, the high pH materials have a pH of about 11.
Referring more specifically to FIG. 6, a wafer is introduced to a CMP machine for short polish or rework processing. Step 610 . As noted above, ensuring a high pH on the surface of the wafer at platen 2 perhaps the most important thing for preventing additional defects from being introduced to the surface of the wafer during a short polish on platen 2 . Step 620 . Several embodiments for ensuring that the pH is high at the wafer surface on platen 2 will be described herein. Once the pH of the wafer surface is high, and the wafer surface is in contact with the polishing pad of platen 2 , the wafer is polished on platen 2 , for less than 15 seconds. Step 630 . The wafer short polish or rework is then completed. Step 640 . On a multi-platen CMP machine, such as is shown in FIG. 3, the wafer is rinsed and transferred to a third platen where it is buffed and than post-CMP processing (i.e. scrubbing, rinsing and/or drying) can occur. After which, the wafer short polish or rework is complete. Step 650 . The slurry may be rinsed from the polishing platens using a high pressure rinse system, such as is disclosed in commonly assigned U.S. patent application Ser. No. 09/871,507.
Referring now to FIG. 7, there is shown one embodiment of the present inventions. The embodiment of FIG. 7 utilizes the principal of maintaining the pH high at the surface of the wafer prior to the short polish on a multi-platen machine 705 , by skipping entirely in the rework process on one of the two polishing platens. In the present embodiment the first platen 720 is skipped. However, it can be seen that the first platen may be used and the second platen of the multi-platen machine skipped. This prevents exposure to slurry abrasives and lower pH that typically occurs when starting polish on the second platen 730 during the rework polish of the wafer. In this way, no pH lowering deionized water is transferred on the wafer surface to the second platen 730 from the first platen 720 . In a full length polish system, this exposure to a lower pH is not normally a problem, since a typical polish process removes a large amount of oxide while on platen 730 . However, short polishes do not remove much film and the slurry particles survive to the end of the process. Skipping the first platen in reworking the wafer 105 reduces the number of final defects in the wafer. This embodiment is particularly useful in processes where the total rework polish time of the wafer on the second platen is less than 30 seconds.
After the short polish on platen 730 , the wafer 105 is rinsed with deionized water and transferred to platen 740 , where it is buffed while being kept wet with deionized water. After buffing, post CMP polish processing occurs. Optionally, the wafer is scrubbed with high pH solution in brush scrubbers 750 and/or 755 and dried at the drying station 760 .
FIG. 8 is a graph of oxide removed vs. time and of added defects vs. time for wafers being reworked on the second platen of a multi-platen system in accordance with the embodiment of FIG. 7 . More particularly, line 810 of FIG. 8 shows oxide removed vs. second platen time for a wafer that is placed on second platen and having skipped the first platen. Line 812 shows the added defects vs. time on the second platen for a wafer that has skipped the first platen. Note that the defect peak at 6 seconds seen in FIG. 5 is not repeated for wafers that skip the first platen and undergo oxide removal only on the second platen.
Referring now to FIG. 9, there is shown a block diagram of another embodiment of the short polish system that alleviates high defectivity problems typically associated with short polish processes on a multi-platen CMP machine 905 in accordance with the present inventions. The embodiment of FIG. 9 achieves this result by priming the pad on platen 930 with large amounts of slurry prior to the wafer 105 being transferred from platen 920 for the purpose of raising the pH oat the surface of the wafer by displacing any deionized water carried over with the wafer from the carrier or prior platen.
For example, in one experiment the pad 930 was primed with slurry for 25 seconds prior to the wafer transfer from platen 920 . This differs greatly from the standard slurry prime of around 8 seconds. In the present embodiment, it is preferred that the pad be primed with slurry prior to polishing for 9-30 seconds. More preferably, the pad is primed with slurry prior to polishing for 10-20 seconds. If cost were not an object, the polishing pad of the present embodiment would be preferably primed with slurry for 25 seconds prior to polishing the wafer surface. However to achieve an optimal balance between slurry cost and defectivity, a slurry prime in the range from 9-20 seconds may be chosen. It has been found that the extra second(s) of priming can be critical to reducing defectivity. Additionally, it has been found that by heavily priming the pad with slurry prior to polishing improves the removal uniformity on the surface of the wafer.
Priming the pad with large amounts of slurry maintains the high pH of the wafer surface at platen 930 by completely displacing the deionized water on the surface of the wafer 105 which is carried over after the rinse of platen 920 . Once the pH is high at the wafer surface on the pad 930 , the wafer is polished. In the present inventions, by raising the pH it has been found that defectivity is improved for short polishes of less than 15.
After the short polish on platen 930 , the wafer 105 is rinsed with deionized water and transferred to platen 940 , where it is buffed while being kept wet with deionized water. After buffing, post CMP polish processing occurs. If desired, the wafer is scrubbed with high pH solution in brush scrubbers 950 and/or 955 and dried at the drying station 960 .
FIG. 10 is a graph of oxide removed vs. time and of added defects vs. time for wafers being reworked on the second platen of a system in accordance with the embodiment of FIG. 9 . More particularly, line 1010 of FIG. 10 shows oxide removed vs. second platen time for a wafer that is placed on a heavily slurry primed second platen after transfer from a short polish on a first platen. Line 1012 shows the added defects vs. time on a second platen 2 for a wafer that has skipped the first platen. Note again that the defect peak at 6 seconds seen in FIG. 5 is not repeated for wafers processed in accordance with the present embodiment. Additionally, note that in FIG. 10 the removal rate of the film starts high immediately. This indicates that the pH is high at the beginning of the polish process.
Additionally, in the embodiments of FIGS. 7 and 9, it is desired that downforce at the second platen of the process be optimized to minimize defectivity, but still maintain other polish parameters to acceptable levels. As described above, it has been found that downforce has a dramatic impact on the final defectivity of the wafer. Defect counts were found to be almost 10 times higher for a wafer polished with only 1 psi of downforce higher. As such, in the preferred embodiments of the present inventions, it is desired that the downforce on the wafer be between 0 and 5 psi during the short polish. It is more preferred that the downforce on the wafer be between about 1 and 4 psi. It is most preferred that the downforce on the wafer at the second platen is chosen to be between 1 and 3 psi for the short CMP polish of the present.
While the inventions have been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.
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A short CMP polish process is provided which removes minimal amounts of oxide and reduces defectivity at the surface of the wafer during short periods of rework by maintaining a high pH at the wafer surface in the presence of a high pH slurry. In one embodiment of the present inventions, the first platen of a multi-platen CMP machine is skipped for polishes of a short duration. In a second embodiment, a large amount of slurry is used to prime the second polish platen, thus displacing deionized water at the surface of the wafer which would ordinarily lower the initial pH of the process. Additionally, downforce may be minimized to reduce defectivity.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 13/832,198, filed Mar. 15, 2013, which application claims priority to and benefit under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/702,404, filed on Sep. 18, 2012, in the name of the present inventor, this provisional application being incorporated herein by reference.
FIELD OF THE INVENTION
The field relates to a cementitious material that possesses favorable toughness and resists spalling.
BACKGROUND OF THE INVENTION
There is a long-felt need for a cementitious material having sufficient strength while also possessing favorable toughness. Typically, overall strength decreases, with one example being compressive strength, while toughness increases. Strength is defined as force per unit area, i.e. energy per unit volume, while toughness is energy per unit area.
The toughness index, as evaluated by the area under the load-deflection curve, is considered as a measure of the energy absorption capability of the material during fracture in the non-linear portion of the curve. The ACI Committee 544 (83-85) has defined the toughness index as the measure of the amount of energy required to deflect a fiber concrete beam, used in the modulus of rupture test, by a given amount compared to the energy required to bring the fiber beam to the point of first crack.
In ductile materials, with one example being metals, the fracture process zone, though small, is surrounded by a large nonlinear plastic zone, whereas in quasi-brittle materials, with an example being concrete, the fracture process zone occupies practically the entire zone of nonlinear deformation. In contrast, the nonlinear zone is practically absent in brittle materials.
When creating cementitious materials for ballistic or blast applications, two very important design considerations are meeting the specified mechanical strength requirements and minimizing the amount of spall at failure. One traditional means for designing hydraulic cement based materials to meet such performance requirements is to densify the material's microstructure while incorporating some means of reinforcement. Commonly used reinforcing materials are often fibrous materials—likely steel fibers. Steel fibers are primarily responsible for increases in ductility for cementitious materials possessing dense microstructures. In most densified cementitious materials, the coarse aggregate in mix designs is substituted with finely ground fillers in conjunction with high performing water reducers to create a very dense microstructure possessing fewer capillary networks ultimately leading to a somewhat ideal “spacing packing” design for much better distribution of applied load. This methodology is also referred to as the “packing density optimization principle” and such materials may also be referred to as “densified spacing packing” (DSP) materials. A few common examples of finely ground fillers are ground quartz, silica fume, fly ash and ground granulated blast furnace slag. Typically these fine materials are of smaller particle size when compared with un-hydrated cement grains allowing the finely ground fillers to occupy spaces between cement grains providing homogeneity throughout the microstructure for better, more consistent distribution of applied loads. These dense materials often possess incredible compressive strengths, though the tensile strength often remains in the realm of 10% of compressive strength. As previously mentioned, fiber addition often improves tensile strength. Materials falling into this dense microstructure classification with incredibly high compressive strength values are often referred to as ultra high performing concrete (UHPC) or very high performing concrete (VHPC). The densified spacing packing “DSP” based cementitious materials are however distinctly brittle, the more so the higher the compressive strength. In fact, although the tensile strength is about one tenth of the compressive strength, the material is intrinsically brittle. Therefore, a process such as is described herein can be incorporated into mix designs for DSP based materials for mitigating spall in blast or ballistic applications.
A material such as is described herein embodies a completely different approach for meeting the specified mechanical strength requirements for ballistic or blast applications while minimizing the amount of spall at failure. A material such as is described herein includes latex polymers in cementitious materials mix designs. As opposed to the “densification of microstructure” methodology, the microstructures of polymer modified cementitious materials become less dense with increases in polymer content due to tough, flexible polymer films occupying the void spaces within the microstructure. The microstructural behavior of polymer modified materials changes with increases in polymer concentration. Low polymer concentrations create very tough materials which fail in somewhat brittle fashion; whereas, high polymer concentrations create somewhat flexible materials which fail in elastic fashion. Essentially, polymer concentration influences the material's modulus of elasticity. Higher concentrations of polymer per specific volume of microstructure decrease the modulus of elasticity thereby forming a more ductile material.
These polymers are film forming thermoplastic materials widely known for use as mechanical property modifiers for specialty cementitious products. These film forming polymers are known to increase direct tensile strength of mortars by filling void spaces with tough, flexible polymer film. These film-forming polymers are known to increase adhesion strength to materials by forming mechanical bonds with the substrate. For example, polymer modified mortars with higher polymer/cement ratio demonstrate acceptable adhesion performance to non-porous substrates, with an example being glass. Such improvements in both adhesion characteristics and ductile behavior highlight a material such as is described herein as ideal for use in applications requiring coating of other construction materials for mitigating spall during failure of said materials.
In contrast to the mechanical property correlations inherent to traditional cementitious materials, polymer modified cementitious materials possess significantly higher direct tensile strengths and flexural strengths (modulus of rupture). In polymer modified cementitious materials, both direct tensile strength and flexural strength increase to some optimum value before beginning a decreasing trend with increases in polymer/cement ratio. Compressive strengths of polymer modified cementitious materials are often lower than compressive strength of traditional cementitious materials due to the presence of tough, flexible polymer film within the pore network of the polymer modified cementitious materials. The polymer alone behaves as a rubber like material which correlates to decreases in compressive strength with increases in polymer dosage. Such behavior of polymeric material has the potential to lead to creep type behavior for select mix designs. Depending upon area of application, mitigating creep behavior should not be limited to methods such as selecting interlocking aggregates or adding mesh type reinforcing materials, not limited to mesh materials containing fabrics, yarns, wires or nano-tubes.
The mechanical property performance of polymer modified cementitious materials can be strictly controlled by varying the polymer/cement ratio. In other words, the ductile behavior of polymer modified cementitious materials can be strictly controlled by adjusting the polymer/cement ratio. The mechanical property performance of polymer modified cementitious materials can also be influenced by both polymer chemistry and polymer glass transition temperature (Tg); however, the polymer/cement ratio is always to be taken into account when making a material such as is described herein.
In latex polymer modified cementitious materials, the polymer is dispersed somewhat uniformly throughout the material microstructure. Increasing the polymer/cement ratio increases the amount of polymer per given volume of material. The polymer is a tough, flexible material. As the polymer/cement ratio increases, the amount of tough, flexible material increases allowing a transition from brittle to ductile behavior with increasing polymer/cement ratio. As previously mentioned, both direct tensile strength and flexural strength increase up to an optimum value before beginning a gradual decrease with increasing polymer/cement ratio. Even though compressive strength, tensile strength and flexural strength begin to decrease with increasing polymer/cement ratio, all is not lost in terms of material behavior as the percent elongation at break for uniaxial direct tensile testing continually increases with increases in polymer/hydraulic binding agent ratio excluding influence of other reinforcing materials with examples not being limited to fibers, rebar and mesh. Such behavior highlights a material such as is described herein as ideal for mitigating spall in specific applications.
High polymer/cement ratio cementitious materials exhibit extraordinary behavior when compared with traditional, brittle cementitious materials. High polymer/cement ratio cementitious materials will display a yield curve on a stress/strain diagram likely with greater area under the curve when compared with traditional cementitious materials. High polymer/cement ratio materials often display a longer plateau for the yield curve as the material fails and the platens of the testing machine move a greater distance during failure when compared with materials more brittle in nature. Such a longer plateau and greater area under the stress/strain curve highlight the increased toughness of these high polymer/cement ratio materials. Aforementioned behavior, akin to that of greater elongation at break during uni-axial direct tensile strength testing of a material such as is described herein, creates a set of circumstances such that a material such as is described herein can incorporate various materials, which previous reports create the common perception of it being well known said materials are less effective when incorporated with cementitious materials versus incorporation with materials more elastic in behavior. An example of such material should not be limited to aramid yarn spun in the form of Kevlar fabric. It is well known to those skilled in the art that Kevlar K29 mesh is commonly used as the workhorse in soft armor or soft ballistic materials. Kevlar K29 is ideal for use in soft armor as K29 may elongate some 3% or more before failure. When constrained, it is believed a certain number of layers of K29 are less effective when compared with an identical number of layers of K29 allowed room for elongation when subject to loading. The increased ductile behavior of higher polymer/cement ratio cementitious materials creates an environment conducive for incorporation of high performance, engineered type materials into design of materials resulting from a process such as is described herein. Additionally, a material such as is described herein may serve as a suitable material for incorporation of recycled materials, not being limited to recycled aramid type materials.
When subjected to sudden high velocity impact or blast loading, the amount of generated spall decreases significantly with increasing polymer/cement ratio. The continuous polymer film throughout the material microstructure binds the constituent materials together. The tough, flexible polymer film bridges micro-cracks as they form, thus increasing the material's capacity for energy absorption. This adequately explains the observed results for reduced cracking and spall for the tested materials with increases in polymer/cement ratio. A material such as is described herein is seen as a suitable low cost alternative material for inclusion during manufacture of Chobham type armor components, or any armor type components, whether they be used for construction of personal defense devices or armoring of vehicles, components, structures, vessels, crafts or other tangible objects.
Given the ability of a material such as is described herein to absorb more energy during crack formation processes, such microstructural behavior creates ideal circumstances for incorporation of specifically designed objects, with examples not being limited to items comprising wood, glass, ballistic glass, plexi-glass, safety glass, thermoset polymer based materials, thermoplastic polymer based materials, composites, polymer composites, ceramic type materials, ceramic tiles, tiles produced from any material or combination or materials, ball bearings, metals, alloys, boron carbide, silicon carbide, aluminum oxide, aluminum nitride, titanium boride, or the like for purposes of either absorbing energy of projectiles or altering the path of the projectile, thereby increasing the total distance the projectile must travel before nearing a surface and creating spall as the projectile progresses some distance through the microstructure of the host material. Behavior of such materials is deemed as ideal for meeting the need for cheaper construction materials for the purpose of providing a specified degree of protection for persons or property subject to ballistic or blast loading. Such construction materials can be used to form virtually any conceivable object or geometry, either load bearing or non-load bearing, either as a sole material or in combination with other construction materials and methods of construction.
Various methods exist for classifying behavior of materials subject to blast or ballistic type loading. Common test methods or schemes for ballistic type loading should not be limited to Underwriters Laboratories UL 752, National Institute of Justice NIJ 018.01, United States State Department SD-SDT-02.01, ASTM F-1233, European Normal Standard DIN EN 1063 or HP White Laboratories HPW-TP 0500.02. A listing of requirements set forth when testing according to UL 752 is discussed in reference with Table 9 of this document. Examples of a material such as is described herein tested according to UL752 were tested at a distance of approximately 10 ft or approximately 3.05 m from the sample.
Numerous reports exist describing a need for development of higher performing cementitious materials which will maintain greater degrees of structural integrity with reduced potential for releasing fragmented projectiles when exposed to either blast or ballistic type forces. A material such as is described herein accordingly provides higher-performing cementitious materials which will maintain a greater degrees of structural integrity with reduced potential for releasing fragmented projectiles when exposed to either blast or ballistic type forces.
SUMMARY OF THE INVENTION
A material such as is described herein provides inter alia an optionally load-bearing essentially shaped cementitious product manufactured by steps comprising:
(a) admixing a liquid medium, a hydraulic binding agent, a latex polymer and optionally one or more other components, wherein the mass ratio of hydraulic binding agent to latex polymer is between about 1:1000 and about 1000:1, to form a mixture;
(b) placing the mixture in an essentially prismatic disposition wherein the mixture sets, thereby forming a set essentially shaped mixture; and
(c) permitting the set essentially shaped mixture to harden, thereby forming the essentially shaped cementitious product;
wherein a 51-mm-thick sample of the product halts a full metal jacket bullet fired into the sample's thickness from a 9 mm handgun at a distance of 15 meters and wherein spallation resulting from entry of the projectile into the thickness occurs in a zone on the entry surface not greater than about 50 times the area of the bullet hole resulting from the bullet's entry into the thickness of the sample.
A material such as is described herein accordingly provides a material less susceptible than materials known in the art to brittle failure in either blast or ballistic applications. A material such as is described herein may incorporate latex polymer film into a microstructure of the material as a means for influencing toughness characteristics. A material such as is described herein may possess a specified ductile behavior according to the material's the polymer/cement ratio, i.e., defining the material's modulus of elasticity according to the polymer/hydraulic binder ratio. A material such as is described herein may be used to create either individual specimens or in full pour type applications, with examples not being limited to bricks and walls, respectively. As a coating, a material such as is described herein may be applied with any common set up, with examples not being limited to pour, gunnite, shot-crete, low pressure spray, trowel, brush, roller, knife, direct injection, pumping apparatus or simply applied by hand.
Direct tensile strength and modulus of rupture of a polymer modified cementitious material may increase with increases in polymer/cement ratio up to some optimum level, then the mechanical property strength values gradually decrease with increases in polymer/cement ratio. Material deformation continually increases as a result of more elastic behavior with increases in polymer/cement ratio. In direct tensile strength testing, elongation at break increases continually with increases in polymer/cement ratio though strength values may gradually decrease beyond an optimum value with increases in polymer/cement ratio.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 shows brittle failure of non-polymer modified control mortar sample after being shot with a 9 mm 115 grain handgun bullet at a range of 15 m (49 ft).
FIG. 2 shows a successful stop while maintaining structural integrity for polymer modified cement mortar sample with polymer/cement ratio of 2/5 after being shot with a 9 mm 115 grain handgun bullet at a range of 15 m (49 ft).
FIG. 3 shows a pass through while maintaining structural integrity for polymer modified cement mortar sample with polymer/cement ratio of 1/1 after being shot with a 9 mm 115 grain handgun bullet at a range of 15 m (49 ft).
FIG. 4 shows a pass through while maintaining structural integrity for polymer modified cement mortar sample with polymer/cement ratio of 2/1 after being shot with a 9 mm 115 grain handgun bullet at a range of 15 m (49 ft).
FIG. 5 shows bullet entrances for polymer modified hydraulic cement mortars at polymer cement ratios of 2/5 (bottom), 1/1 (middle) and 2/1 (top).
FIG. 6 shows bullet exits for polymer modified hydraulic cement mortars at polymer cement ratios of 2/5 (bottom), 1/1 (middle) and 2/1 (top) where it can be seen that p/c=2/5 stopped the bullet while maintaining structural integrity, p/c=1/1 had little spall while maintaining structural integrity and p/c=2/1 had even less spall while maintaining structural integrity.
FIG. 7 shows a bar graph depicting direct tensile strength of polymer modified mortar samples at polymer/cement ratios of 0.15, 0.3 and 0.45.
FIG. 8 shows a bar graph depicting percent elongation at break for direct tensile strength dog bone samples at polymer/cement ratios of 0.15, 0.3 and 0.45.
FIG. 9 shows a bar graph depicting flexural strength of polymer modified cement mortar samples at polymer/cement ratios of 0.15, 0.3 and 0.45.
FIG. 10 shows a bar graph depicting compressive strength of polymer modified cement mortar at polymer/cement ratios of 0.15, 0.3 and 0.45.
FIG. 11 shows examples of sample specimens for ASTM C307 uni-axial direct tensile strength testing.
FIG. 12 shows a bar graph depicting percent elongation for broken dog bone samples with only variable being polymer/cement ratio.
FIG. 13 shows a mortar block with polymer/cement ratio approximately 1/7 after being shot 3 times with 44 Magnum.
FIG. 14 shows a mortar block with polymer/cement ratio approximately 5/7 after being shot 3 times with 44 Magnum with shots 2 and 3 virtually being on top of one another.
FIG. 15 shows a mortar block with polymer/cement ratio approximately 7/7 after being shot 3 times with 44 Magnum.
FIG. 16 shows mortar blocks displayed in FIGS. 13, 14 and 15 after 3 shots with 44 Magnum followed with 5 shots from 223 rifle. From left to right, blocks have a polymer/cement ration of 5/7, 7/7 and 1/7, with a polymer/cement ratio of 1/7 demonstrating complete failure and significant amounts of spall.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention now will be described more fully hereinafter. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. As used in this specification and the claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. “Or” as in “A or B” is conjunctive, not disjunctive, and accordingly in this instance means at least one member of the set {A, B}.
A material such as is described herein provides inter alia an optionally load-bearing essentially shaped cementitious product manufactured by steps comprising:
(a) admixing a liquid medium, a hydraulic binding agent, a latex polymer and optionally one or more other components, wherein the mass ratio of hydraulic binding agent to latex polymer is between about 1:1000 and about 1000:1, to form a mixture;
(b) placing the mixture in an essentially prismatic disposition wherein the mixture sets, thereby forming a set essentially shaped mixture; and
(c) permitting the set essentially shaped mixture to harden, thereby forming the essentially shaped cementitious product;
wherein a 51-mm-thick sample of the product halts a full metal jacket bullet fired into the sample's thickness from a 9 mm handgun at a distance of 15 meters and wherein spallation resulting from entry of the projectile into the thickness occurs in a zone on the entry surface not greater than about 50 times the area of the bullet hole resulting from the bullet's entry into the thickness of the sample.
A material such as is described herein accordingly provides a material less susceptible than materials known in the art to brittle failure in either blast or ballistic applications. A material such as is described herein may incorporate latex polymer film into a microstructure of the material as a means for influencing toughness characteristics. A material such as is described herein may possess a specified ductile behavior according to the material's the polymer/cement ratio, i.e., defining the material's modulus of elasticity according to the polymer/hydraulic binder ratio. A material such as is described herein may be used to create either individual specimens or in full pour type applications, with examples not being limited to bricks and walls, respectively. As a coating, a material such as is described herein may be applied with any common set up, with examples not being limited to pour, gunnite, shot-crete, low pressure spray, trowel, brush, roller, knife, direct injection, pumping apparatus or simply applied by hand.
Direct tensile strength and modulus of rupture of a polymer modified cementitious material may increase with increases in polymer/cement ratio up to some optimum level, then the mechanical property strength values gradually decrease with increases in polymer/cement ratio. Material deformation continually increases as a result of more elastic behavior with increases in polymer/cement ratio. In direct tensile strength testing, elongation at break increases continually with increases in polymer/cement ratio though strength values may gradually decrease beyond an optimum value with increases in polymer/cement ratio.
A material such as is described herein may accordingly possess any of a wide range of performance characteristics. Table 1 displays experimental results for a rapid setting hydraulic cement based patch and repair mortar at different polymer/cement ratios after curing in a sealed plastic container in ambient outdoor Kentucky springtime conditions for 27 days (13 Mar. 2012-9 Apr. 2012) when exposed to a single gunshot from a 9 mm handgun with 115 grain full metal jacket bullets at a distance of 15 meters (49 ft).
TABLE 1
Results for square mortar panel with side length 165 mm (6.5 in)
and depth 51 mm (2 in) when shot with 9 mm 115 grain
handgun bullet at a distance of 15 m (49 ft).
The term “p/c” refers here as elsewhere in the
present document to polymer/cement ratio.
Mortar
Bullet
Distance
response
observations
Control
9 mm 115 grain
15 m
brittle failure
Spall
p/c = 2/5
9 mm 115 grain
15 m
no failure
no spall
p/c = 1/1
9 mm 115 grain
15 m
pass through
little spall
p/c = 2/1
9 mm 115 grain
15 m
pass through
little spall
As seen in Table 1, a non-polymer modified control sample experienced brittle failure. A mortar with polymer/cement ratio of 2/5 stopped a bullet with little cracking A mortar with polymer/cement ratio of 1/1 allowed a bullet to pass completely through with small entrance and somewhat small exit displaying little spall and little cracking A mortar with polymer/cement ratio of 2/1 also allowed a bullet to pass completely through with small entrance and somewhat small exit displaying little spall and little cracking.
These results were obtained with stand-alone, unconfined mortar specimens which were 51 mm (2 in) thick. The failure modes associated with the control, p/c=2/5, p/c=1/1 and p/c=2/1 provide a clear illustration of optimum strength characteristics with increasing polymer/cement ratio. Although materials with p/c=1/1 and p/c=2/1 allowed complete bullet pass through for these thin members, such materials present viable options for mitigating spalling behavior in stand alone applications as increasing specimen thickness increases a material's capacity to absorb energy. An important characteristic for materials tested at this specimen thickness is the relatively insignificant amount of cracking for mortars with polymer/cement ratio of 2/5, 1/1 and 2/1. Insignificant cracking illustrates a material's ability to maintain sufficient structural integrity in ideal applications.
A material such as is described herein displays excellent adhesion characteristics to cementitious materials. Polymer modified cementitous materials typically result in cohesive failure of the cement based substrate material when tested in direct pull off testing similar to ASTM C1583, Standard Test Method for Tensile Strength of Concrete Surfaces or the Bond Strength or Tensile Strength of Concrete Repair and Overlay Materials by Direct Tension (Pull Off Method). Given the likelihood the substrate material will fail before the adhesion bond fails, a material such as is described herein provides a spall-resistant polymer modified cementitous coating material. Furthermore, a material such as is described herein is suitable for use either creating or supplementing spall liners, with examples of spall liners not being limited to use with either construction or “up armoring” of armored vehicles, maritime vessels, structures and automobiles. For example, at a p/c=1/1 after 28 days of curing in ambient conditions, a material such as is described herein provided a very tough, flexible polymer modified cementitious coating with flexural strength values of approximately 10 MPa (1450 psi) and direct tensile strength values of approximately 7 MPa (1000 psi) and compressive strength values near 28 MPa (4000 psi) effectively mitigating spall if the cementitious substrate material fails in brittle fashion as a result of a sudden shock wave, vacuum or gunshot.
A material such as is described herein can be applied to reinforced concrete structures in similar fashion to automobile crumple zones. Polymer modified cementitous materials are typically lower in compressive strength, but higher in both direct tensile strength and flexural strength when compared with contemporary cementitious materials. Such mechanical property correlations allow for significant material deformation while maintaining some sense of structural integrity. For the sake of load bearing columns in blast or ballistic applications, a section of column is cast with polymer modified mortar with sufficient compressive strength and ductility as defined by polymer/cement ratio such that the polymer modified portion will slightly deform while maintaining the majority of its structural integrity when exposed to significant, sudden loads, similar to a single-use shock absorber, as these polymer modified cementitious materials have no memory. Such behavior characteristic of a material such as is described herein can be generalized to the case of being incorporated into development of layered systems designed for ballistic or blast loading, not being limited to the concept underlying functionality of Chobham type armor systems.
A material such as is described herein reduces spall of cementitious materials under blast or ballistic loading scenarios. A material such as is described herein may be utilized to create spall liners, modular units, cast in place structures, coating materials, insert materials, or any number of possibilities given the vast range of mechanical property performance correlations which can be achieved by varying the polymer/cement ratio in cementitious materials formulations. A material such as is described herein allows creation of ductile cementitious materials without the addition of fibers or other means of reinforcement, though addition of fibers and reinforcing materials may benefit the performance of a material such as is described herein for specific applications.
Latex polymers suitable for a material such as is described herein may include elastomeric latexes, thermoplastic latexes and thermosetting latexes or any combination thereof. Elastomeric latexes consist of natural and synthetic rubbers. Thermoplastic latexes are not limited to examples such as polyacrylic esters, copolymers of vinyl acetate/ethylene (VAE or EVA), terpolymers of vinyl acetate/ethylene/vinyl chloride (VAE/VC), terpolymers of vinyl acetate/ethylene/veova (VAE/Veova), VAE/Veova/VC, styrene acrylics, poly styrene acrylic esters, polyvinyl acetate, polyvinyl propionate, polypropylene, poly vinylidene chloride vinyl chloride (PVDC). Thermosetting latexes are not limited to epoxies. Examples of VAE liquid polymer dispersions are Vinnapas 526BP and Mowilith LDM 1852. An example of a styrene butadiene rubber (SBR) liquid polymer dispersion is Axilat SB500. An example of an acrylic liquid polymer dispersion is Axilat L8840.
Dispersible polymer powders are characterized such that they disperse readily into their constituent polymer components when exposed to water thereby forming a tough, elastic water resistant polymer film. Examples of dispersible polymer powders according to a material or process such as is described herein are copolymers of vinyl acetate and ethylene (VAE) are Vinnapas 5044N and Vinnapas 5010N. A suitable example for a polymer powder of styrene butadiene rubber (SBR) chemistry is Axilat PSB150.
When used in the present context, the term “hydraulic binder” refers to a pulverized material in the solid, dry state, which when mixed with water yields mixtures which are able to set and harden, with a common example being the term “cement”. A hydraulic binder may comprise one or more individual component materials. A hydraulic binder may undergo setting and hardening when exposed to suitable medium. Utilizing cement chemistry nomenclature where C=CaO, Ś=SO 3 , S=SiO 2 , A=Al 2 O 3 , H=H 2 O, F=Fe 2 O 3 , N=sodium based materials, K=potassium based materials, any of such hydraulic binder materials may hydrate to form materials containing C-A-Ś-H type phases and (N,K)-A-Ś-H type phases in addition to more traditional type phases common to ordinary portland cement hydration. Examples of such individual component materials should not be limited to all forms of calcium sulfate, hydrated lime, quicklime, alumina, alumina tri-hydrate, alite, belite, tri-calcium aluminate, yeelimite (kleins compound), calcium aluminate, C 12 A 7 , coal ash, slag, silica fume, pozzolana, clay, bauxite, red mud, brownmillerite or any other suitable material or combination of materials which when exposed to water or other suitable medium is able to set and harden. The term “cement” includes hydraulic and alite cements such as portland cement, blended cement, slag cement, pozzolanic cement, calcium aluminate cement, calcium sulfoaluminate cement or any other common cementing material or combination thereof.
A material such as is described herein may also comprise one or more other materials such as viscosity modifiers commonly used in cementitious systems. These viscosity modifiers are typically polysaccharides and their derivatives including polysaccharide ethers soluble in water such as cellulose ether, starch ether (amylose and/or amylopectin and/or their derivatives), guar ether and/or dextrins. It is also possible to use synthetic polysaccharides such as anionic, non-ionic or cationic heteropolysaccharides such as xanthan gum or wellan gum. The polysaccharides can, but need not, be chemically modified with carboxymethyl groups, carboxyethyl groups, hydroxyethyl groups, hydroxypropyl groups, methyl groups, ethyl groups, propyl groups and/or long chain alkyl groups. Further natural stabilizing systems consist of alginates, peptides and/or proteins such as gelatin, casein and/or soy protein. Examples include dextrins, starch, starch ether, casein, soy protein, hydroxyl alkyl cellulose and/or alkyl hydroxalkyl cellulose. Other synthetic stabilizing systems include one or several polyvinyl pyrrolidones and/or polyvinyl acetals having molecular weights of approximately 2000 to 400,000; fully or partially saponified and/or modified fully or partially saponified poly-vinyl alcohols with a degree of hydrolysis of approximately 70 to 100 mole %, or in another respect approximately 80 to 98 mole %. Additionally, poly-vinyl alcohols may be incorporated at larger percentages to further enhance a material's ability to mitigate spall. Commonly referred to rheology modifying materials have been known to include methylhydroxyethylcellulose, hydroxymethylethylcellulose, carboxymethylcellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxyethylpropylcellulose, etc.
A material such as is described herein may also comprise one or more other materials such as plasticizers, super-plasticizers, high range water reducers or any suitable product which delivers desired characteristics. Common materials used for such purposes are melamine sulphonate formaldehyde condensates, naphthalene sulphonates, calcium lignosulphonates, sodium lignosulphonates, saccharose, sodium gluconate, sulphonic acids, carboxylates, poly-carboxylates, carboxylic acids, polyhydroxycarboxilic acids, sulphonated melamine or any other suitable material, whether it be naturally occurring or processed. Examples are not limited to the Glennium family of products or the Melflux family of products.
A material such as is described herein may also comprise one or more other materials such as set retarders. Set retarders are often used to delay the hydration reactions associated with hydraulic binders and possibly reactions of other constituent components. Set retarders can vary in effectiveness of delaying onset or rapidity of hydration for differing hydraulic binders and/or different or varying combinations of constituent materials. Commonly used set retarders are not limited to tartaric acid, citric acid, sodium citrate, hydroxyl carboxylic acids and their salts, malic acid, sodium gluconate, sucrose, etc.
A material such as is described herein may also comprise one or more other materials such as set accelerators or accelerating admixtures. Such materials are frequently used, but not limited to increasing the rate of hydration reaction or providing some means of control for specific interactions which are inevitable when certain materials interact under certain conditions. Common examples of set accelerators or accelerating admixtures include but are not limited to lithium carbonate, calcium formate, quicklime, calcium oxide, sodium chloride, various alkali earth metals and their salts, aluminous materials when combined with other proper constituents, etc.
A material such as is described herein may also comprise one or more other materials such as surfactants for various purposes, whether they be foaming materials, de-foaming materials or provide any other desired properties. Suitable foaming and stabilizing surfactants may include but are not limited to mixtures of an ammonium salt of an alkyl ether sulfate, a cocoamidopropyl betaine surfactant, a cocoamidopropyl dimethylamine, oxide surfactant, mixtures of an ammonium salt of an alkyl ether sulfate surfactant, a cocoamidopropyl hydroxysultaine surfactant, hydrolyzed keratin, an alkyl or alkene dimethylamine oxide surfactant, aqueous solutions of an alpha-olefinic sulfonate surfactant and a betaine surfactant and/or any other suitable materials. An example of a foaming material is ZONESEAL 2000 foaming additive commercially available from Halliburton.
A material such as is described herein may also comprise one or more other materials such as defoaming materials which also may be known as air detrainers. These types of defoaming materials can be very important for creating impermeable coatings. These defoaming materials typically decrease the amount of entrained air within the designed system. Common examples of these materials are tributyl phosphate dibutyl phthalate, octyl alcohol, water insoluble esters of carbonic and boric acid as well as silicone based materials. Common examples of available defoamers include but are not limited to Agitan P800 and Surfynol MD600.
A material such as is described herein may also comprise one or more other materials such as “fugitive plasticizers” or “coalescing solvents” with a primary function being not limited to aiding the mechanisms for facilitating film formation or film integration during either the drying, setting, hardening or overall curing process. Some common “fugitive plasticizers” or “coalescing solvents” are volatile organic compounds not being limited to the examples including toluene, xylene, n-butyl acetate, ethoxyethyl acetate, ethyleneglycol monobutyl ether acetate, and diethyleneglycol monobutyl ether acetate.
A material such as is described herein may also comprise one or more other materials such as filling materials. Typically, filling materials are finely ground materials. These fillers often possess, but should not be limited to a particle size distribution with both median and mean values less than 100 microns. This is one classification characteristic when comparing fillers and aggregate. Examples of common filling materials or fillers are ground carbonates with examples being calcium carbonate and sodium bi-carbonate, all classifications of clay materials, metakaolin, diatomaceous earth, carbon black, activated carbon, titanium dioxide, finely ground quartz, finely ground silica based materials often referred to as micro-silica, silica fume, fumed silica, kiln dust, pulverized stone, pulverized glass, ultra fine fly ash, fly ash, blast furnace slag, ground granulated blast furnace slag (GGBS), ground recycled materials, pulverized glass, crum rubber, recycled tires, powdered waste from recycling automobiles, powdered waste from recycling electronic components, etc.
A material such as is described herein may also comprise one or more common reinforcing materials typically used in either cementitious materials design or coating materials design such as fibrous materials or mesh type materials. Examples of fiber type materials should not be limited to metal fibers, organic fibers, synthetic fibers, polymeric fibers, carbon nano tube type fibrous materials or any mixture of fibers. Examples of fibers should not be limited to polyvinyl alcohol fibers (PVA), polyacrylonitrile fibers (PAN), polyethylene fibers (PE), high density polyethylene fibers (HDPE), polypropylene fibers (PP) or homo or co-polymers of polyamide or polyimide. Mixtures of any type of fibers may also be used, especially mixtures of fibers with different physical dimensions and different orientations. Addition of fibrous material to cementitious type mixtures may be facilitated by use of a viscosity modifying agent which ensures proper dispersal of fibers throughout the mixture, with an example being Kelco-Crete which is an anionic polysaccharide from CP Kelco. Furthermore, aramid type materials, not limited to currently available material forms such as pulp, yarn, fibers, or mesh, such potentially being comprised of chains with AABB configuration, with examples not being limited to Kevlar, Twaron, Nomex, New Star and Teijinconex, may be included in a multitude of possible arrays. Additionally, novel materials such as combinations of boron oxides and polyethylene may be utilized as means of reinforcement. Mesh type materials may also be used as a means of reinforcement. Examples of mesh type materials should not be limited to metal mesh, alloy mesh, fabric mesh, carbon fiber mesh, carbon nano-tube mesh, fiberglass mesh, polyethylene mesh, polypropylene mesh or aramid mesh. Additionally, materials with more complex design characteristics may be included, with examples not being limited to shear thickening fluids and not so commonly used metals such as depleted uranium. Other more common types of reinforcement should not be limited to theories surrounding practices of pre-stressed concrete, post-stressed concrete, reinforced concrete where any reinforcing type material could potentially be placed within the constructed material with fully bonded orientation, partially bonded orientation, un-bonded orientation; or, the reinforcing material may be bonded in any fashion to any material comprising the constructed material.
A material such as is described herein may also comprise one or more other materials such as materials sometimes needed for protection from microorganism attack. As a result, the mixing process may incorporate fungicides or anti-bacteria substances. Examples of such materials should not be limited to pentachlorophenol, sodium o-phenylphenate and/or various organic mercury compounds.
A material such as is described herein may also comprise one or more other materials such as flame-retarding materials. Examples of flame retarding materials should not be limited to chlorinated paraffin waxes and antimony trioxide.
A material such as is described herein may also comprise one or more other materials such as common aggregate materials not limited to specification of chemical composition or specimen geometry. Examples of common aggregate materials are siliceous materials with one specific example being silica sand, calcium based materials with an example being stone, limestone, river gravel, river sand, pea gravel, pozzolanic material with an example being volcanic rock, bottom ash, cinders, along with numerous other possibilities for both recycled and manufactured aggregates. A material such as is described herein may also comprise engineered aggregate materials such as high performance ceramic aggregate or light weight aggregate.
A material such as is described herein may also comprise one or more other materials such as antioxidants to retard deterioration of polymeric materials, and optionally surface active substances to enhance colloidal stability and ability to “wet out” surfaces. Coating materials may become exposed to acidic materials on the molecular level due to consequences from polymer hydrolysis, with one example being the liberation of hydrogen chloride. Common anti-oxidant materials should not be limited to phenyl-2-naphthylamine or carbon black. Common acid accepting substances for mix design purposes should not be limited to zinc oxide and calcium carbonate.
A material such as is described herein may also comprise one or more other materials such as anti-freeze materials not limited to ethylene glycol or glycerol.
A material such as is described herein may also comprise one or more corrosion inhibiting substances with one example not being limited to sodium benzoate.
A material such as is described herein may also comprise one or more other materials such as powdered metals, powdered alloys or powdered conductive materials for the purposes of producing a coating capable of conducting either electron, proton or neutron transfer in either continuous or dis-continuous fashion. Such conductive materials should not be limited to powder form, such conductive materials may also be added in the form of fibrous material, platy material, ground material, spherical material or virtually any geometry required for the given degree of conductivity.
A material such as is described herein may also comprise one or more other materials such as pigments, dyes or other common color enhancing additives.
A material such as is described herein may also comprise one or more chemical materials with specific purpose such as alkali activating agents or polymer cross-linking agents. Examples of alkali activating agents should not be limited to sodium hydroxide, potassium hydroxide or magnesium hydroxide. Polymer cross-linking agents should not be limited to sodium borate and maleic anhydride.
In an embodiment, a process such as is described herein comprises formation of a mixture comprising sufficient liquid medium, hydraulic binding agent and latex polymer such that the mass ratio of polymer solids (or effective polymeric material amount) to hydraulic binder is within the range of 1/1000 to 1000/1.
In an embodiment, a process such as is described herein comprises formation of a mixture comprising sufficient liquid medium, hydraulic binding agent, superplasticizer and latex polymer such that the mass ratio of polymer solids (or effective polymeric material amount) to hydraulic binder is within the range of 1/1000 to 1000/1.
In an embodiment, a process such as is described herein comprises formation of a mixture comprising sufficient liquid medium, hydraulic binding agent, superplasticizer, rheology modifier and latex polymer such that the mass ratio of polymer solids (or effective polymeric material amount) to hydraulic binder is within the range of 1/1000 to 1000/1.
In an embodiment, a process such as is described herein comprises formation of a mixture comprising sufficient liquid medium, hydraulic binding agent, superplasticizer, rheology modifier, filler and latex polymer such that the mass ratio of polymer solids (or effective polymeric material amount) to hydraulic binder is within the range of 1/1000 to 1000/1.
In an embodiment, a process such as is described herein comprises formation of a mixture comprising sufficient liquid medium, hydraulic binding agent, superplasticizer, rheology modifier, filler, aggregate and latex polymer such that the mass ratio of polymer solids (or effective polymeric material amount) to hydraulic binder is within the range of 1/1000 to 1000/1.
In an embodiment, a process such as is described herein formation of a mixture comprising sufficient liquid medium, hydraulic binding agent, superplasticizer, rheology modifier, filler, aggregate and latex polymer such that the mass ratio of polymer solids (or effective polymeric material amount) to hydraulic binder is within the range of 1/1000 to 1000/1.
In an embodiment, a process such as is described herein comprises formation of a mixture comprising sufficient liquid medium, hydraulic binding agent, superplasticizer, rheology modifier, filler and latex polymer such that the mass ratio of polymer solids (or effective polymeric material amount) to hydraulic binder is within the range of 1/1000 to 1000/1.
In an embodiment, a process such as is described herein comprises formation of a mixture comprising sufficient liquid medium, hydraulic binding agent, filler and latex polymer such that the mass ratio of polymer solids (or effective polymeric material amount) to hydraulic binder is within the range of 1/1000 to 1000/1.
In an embodiment, a process such as is described herein comprises formation of a mixture comprising sufficient liquid medium, hydraulic binding agent, filler, rheology modifier and latex polymer such that the mass ratio of polymer solids (or effective polymeric material amount) to hydraulic binder is within the range of 1/1000 to 1000/1.
In an embodiment, a process such as is described herein comprises formation of a mixture comprising sufficient liquid medium, hydraulic binding agent, filler, rheology modifier and latex polymer such that the mass ratio of polymer solids (or effective polymeric material amount) to hydraulic binder is within the range of 1/1000 to 1000/1.
In an embodiment, a process such as is described herein comprises formation of a mixture comprising sufficient liquid medium, hydraulic binding agent, filler, rheology modifier, accelerator and latex polymer such that the mass ratio of polymer solids (or effective polymeric material amount) to hydraulic binder is within the range of 1/1000 to 1000/1.
In an embodiment, a process such as is described herein comprises formation of a mixture comprising sufficient liquid medium, hydraulic binding agent, filler, rheology modifier, accelerator, retarder and latex polymer such that the mass ratio of polymer solids (or effective polymeric material amount) to hydraulic binder is within the range of 1/1000 to 1000/1.
In an embodiment, a process such as is described herein comprises formation of a mixture comprising sufficient liquid medium, hydraulic binding agent, filler, rheology modifier, accelerator, retarder, means of re-inforcement and latex polymer such that the mass ratio of polymer solids (or effective polymeric material amount) to hydraulic binder is within the range of 1/1000 to 1000/1.
In an embodiment, a process such as is described herein comprises formation of a mixture comprising sufficient liquid medium, hydraulic binding agent, filler, rheology modifier, accelerator, retarder, means of re-inforcement, aggregate and latex polymer such that the mass ratio of polymer solids (or effective polymeric material amount) to hydraulic binder is within the range of 1/1000 to 1000/1.
In an embodiment, a process such as is described herein comprises formation of a mixture containing hydraulic binding agent and latex polymer with any common constituent material for cement mix design with examples not being limited to filler, aggregate, re-inforcing material, accelerator, retarder, plasticizer, super-plasticizer, rheology modifier, flame retarding material, conductive material, insulating material, anti-freeze material, anti-oxidizing material, pigment material, defoaming material, air entraining material, surfactant material, cross-linking material, alkali activating material biocide material, anti-fungal material or fugitive plasticizing material.
The following examples are meant for illustrative purposes.
FIGS. 1-5 illustrate field testing of “spall behavior” for cement mortars similar to the mortars displayed in Table 2. FIGS. 1-5 are further described by reference to Table 1. FIGS. 1-5 clearly demonstrate the utility of a material or process such as is described herein for defining ductile behavior of materials incorporating hydraulic binding agents by varying the material's polymer/hydraulic binding agent ratio. The ductile behavior of the material influences the toughness of the material which defines the “spall behavior” of the material. FIG. 1 illustrates a “control” sample which contains no polymer exhibiting brittle behavior, with significant spall, after being shot with a 9 mm handgun at a distance of 15 m. FIG. 2 illustrates a mortar sample with polymer/cement ratio of 2/5 exhibiting tough, ductile behavior, actually stopping the bullet while maintaining structural integrity after being shot with a 9 mm handgun at a distance of 15 m. FIG. 3 illustrates a mortar sample with polymer/cement ratio of 1/1 exhibiting elastic behavior, actually allowing the bullet to pass through with minimal spall while maintaining structural integrity after being shot with a 9 mm handgun at a distance of 15 m. FIG. 4 illustrates a mortar sample with polymer/cement ratio of 2/1 exhibiting elastic behavior, actually allowing the bullet to pass through with minimal spall while maintaining structural integrity after being shot with a 9 mm handgun at a distance of 15 m.
FIG. 5 and FIG. 6 are bullet entrance and exit comparisons for mortar samples with polymer/cement ratios of 2/5, 1/1 and 2/1. For this specific experiment, the mortar with polymer/cement ratio of 2/5 stopped the bullet with no spall; whereas, the mortars with polymer/cement ratios of 1/1 and 2/1 allowed the bullet to pass through the samples. FIG. 6 illustrates decreased spall for the sample with polymer/cement ratio of 2/1 when compared with the sample with p/c=1/1.
Uni-axial direct tensile strength stress/strain diagrams were obtained per ASTM C307 for mortar formulations in Table 2. Mortars possessing different polymer/cement ratios demonstrated different ductile behaviors. Greater deformation at break was observed with increasing polymer/cement ratio. An increased area under the curve was noted for increasing polymer/cement ratio.
TABLE 2
Polymer modified cement mortar formulations
p/c = 0.15
p/c = 0.3
p/c = 0.45
Hydraulic Binder (g)
660
660
660
Polymer (g)
100
200
300
Fine Sand (g)
1375
1375
1375
Coarse Sand (g)
125
125
125
Admixtures (g)
5
5
5
Water (g)
230
230
250
FIG. 7 and FIG. 8 display direct tensile strength information for the mortars displayed in Table 2. FIG. 7 shows the direct tensile strength being similar for the polymer modified mortars displayed in Table 2. FIG. 8 displays average elongation at break, as a percentage of total specimen length, for the average values displayed in FIG. 10 . FIG. 8 clearly illustrates different ductile behavior as a function of polymer/cement ratio for the polymer modified mortars displayed in Table 2.
FIG. 7 displays direct tensile strength values for the polymer modified mortars listed in Table 2 after curing for seven days in a sealed plastic bag at ambient laboratory temperature of 23° C. (73° F.). The direct tensile strength values for mortars possessing polymer/cement ratios of 0.15, 0.3 and 0.45 are 692 psi (4.8 MPa), 775 psi (5.3 MPa) and 719 psi (4.9 MPa), respectively. Statistical software was utilized for data analysis. One-way ANOVA was used to test the equality of the population means for direct tensile strength testing of polymer modified mortars at polymer/cement ratios of 0.15, 0.3 and 0.45. Results from ANOVA are: F(2/6)=12.9, p=0.007, pooled standard deviation=20.48 and R2=81.14%. Based upon the F value of 12.9 and corresponding p-value=0.007, if an alpha value of 0.05 is chosen, it is safe to reject the null hypothesis and ultimately conclude that at least two means differ from one another, and this inequality is highly unlikely due to chance. Further “post hoc” statistical analysis utilizing Tukey's Honestly Significant Difference Test assigned the mortar with p/c=0.15 to “B” direct tensile strength classification, the mortar with p/c=0.3 to “A” direct tensile strength classification while the mortar with p/c=0.45 has also been assigned to “B” direct tensile strength classification. For the Tukey comparison method, mortars that do not share the same letter strength classification are significantly different.
Table 3 compares common empirical equations for predicting direct tensile strength behavior for ordinary portland cement based concrete with experimental results for polymer modified mortar. The equations were sourced from Hassoun, M. N., 1985, Design of Reinforced Concrete Structures ISBN 0-534-03759-4 and Illston, J. M., Domone, P. L. J., 2001, Construction Materials Their Nature and Behavior, 3rd Edition, ISBN 0-419-25860-3.
The empirical formulations displayed in Table 3 reference the compressive strength (f′c) of concrete for predicting tensile strength behavior. As seen in Table 3, the polymer modified mortars do not follow any of the reported empirical relationships for predicting direct tensile strength behavior as a function of compressive strength. The presence of tough flexible polymer film somewhat uniformly distributed throughout the microstructure increases the ductile behavior of the polymer modified material ultimately leading to deviation from conventional concrete behavior.
TABLE 3
Comparison of polymer modified mortar
experimental results to predictive equations for non-polymer
modified concrete illustrating increased
ductile behavior with increases in polymer/cement ratio
p/c = 0.15
p/c = 0.3
p/c = 0.45
Direct Tensile
ASTM C307
692 psi
775 psi
719 psi
Strength Actual
(4.77 MPa)
(5.34 MPa)
(4.96 MPa)
Direct Tensile
f′dt = 0.06*f′c
221 psi
194 psi
157 psi
Strength
(1.52 MPa)
(1.34 MPa)
(1.08 MPa)
Prediction
Direct Tensile
f′dt = 0.08*f′c
295 psi
259 psi
209 psi
Strength
(2.03 MPa)
(1.78 MPa)
(1.44 MPa)
Prediction
Direct Tensil
f′dt = 0.07*f′c
258 psi
227 psi
183 psi
Strength
(1.78 MPa)
(1.57 MPa)
(1.26 MPa)
Prediction
Direct Tensile
f′dt = 0.11*f′c
405 psi
356 psi
287 psi
Strength
(2.79 MPa)
(2.45 MPa)
(1.98 MPa)
Prediction
FIG. 8 displays percent elongation at break as measured by the universal testing machine for direct tensile strength information. The average elongation at break values for direct tensile strength dog bone samples possessing polymer/cement ratios of 0.15, 0.3 and 0.45 are 4, 6 and 8 percent, respectively. The information displayed in both FIG. 7 and FIG. 8 illustrates a trend for increased ductile behavior with increases in polymer/cement ratio.
FIG. 9 and FIG. 10 display flexural strength information and compressive strength information for the polymer modified mortars displayed in Table 2. The trends displayed in both FIG. 9 and FIG. 10 clearly demonstrate a difference in ductile behavior for mortars possessing different polymer/cement ratios.
FIG. 9 displays flexural strength values for the polymer modified mortars listed in Table 2 after curing for seven days in a sealed plastic bag at ambient laboratory temperature of 23° C. (73° F.). The flexural strength values for mortars possessing polymer/cement ratios of 0.15, 0.3 and 0.45 are 1169 psi (8 MPa), 1406 psi (9.7 MPa) and 1596 psi (11 MPa), respectively. Statistical software was utilized for data analysis. One-way ANOVA was used to test the equality of the population means for flexural strength testing of polymer modified mortars at polymer/cement ratios of 0.15, 0.3 and 0.45. Results from ANOVA are: F(2/6)=96.74, p=0.000, pooled standard deviation=0.26 and R2=96.99%. Based upon the F value of 96.74 and corresponding p-value=0.000, if an alpha value of 0.05 is chosen, it is safe to reject the null hypothesis and ultimately conclude that at least two means differ from one another, and this inequality is highly unlikely due to chance. Further “post hoc” statistical analysis utilizing Tukey's Honestly Significant Difference Test assigned the mortar with p/c=0.15 to “C” flexural strength classification, the mortar with p/c=0.3 to “B” flexural strength classification while the mortar with p/c=0.45 has been assigned to “A” flexural strength classification. For the Tukey comparison method, mortars that do not share the same letter strength classification are significantly different.
Table 4 compares common empirical equations for predicting flexural strength behavior for ordinary portland cement based concrete with experimental results for polymer modified mortar. The equations were sourced from Hassoun, M. N., 1985, Design of Reinforced Concrete Structures ISBN 0-534-03759-4 and llston, J. M., Domone, P. L. J., 2001, Construction Materials Their Nature and Behavior, 3rd Edition, ISBN 0-419-25860-3.
The empirical formulations displayed in Table 4 reference the compressive strength (f′c) of the concrete for predicting flexural strength behavior. As seen in Table 4, the polymer modified mortars do not follow any of the reported empirical relationships. The presence of tough flexible polymer film somewhat uniformly distributed throughout the microstructure increases the ductile behavior of the polymer modified material ultimately leading to deviation from typical concrete behavior.
TABLE 4
Listing of actual experimental flexural strength values
along with empirical relationships typically used to describe
ordinary portland cement based concrete
p/c = 0.15
p/c = 0.3
p/c = 0.45
Flexural Strength
ASTM C348
1169 psi
1406 psi
1596 psi
Actual
(8.06 MPa)
(9.69 MPa)
(11.0 MPa)
Flexural Strength
f′r = 0.1*f′c
368 psi
324 psi
261 psi
Prediction
(2.54 MPa)
(2.23 MPa)
(1.8 MPa)
Flexural Strength
f′r = 0.17*f′c
626 psi
551 psi
444 psi
Prediction
(4.32 MPa)
(3.8 MPa)
(3.06 MPa)
Flexural Strength
f′r = 9.5*
577 psi
541 psi
485 psi
Prediction
((f′c){circumflex over ( )}0.5)
(3.98 MPa)
(3.73 MPa)
(3.34 MPa)
Flexural Strength
f′r = 7.5*
455 psi
427 psi
383 psi
Prediction
((f′c){circumflex over ( )}0.5)
(3.14 MPa)
(2.94 MPa)
(2.64 MPa)
FIG. 10 displays compressive strength values for the polymer modified mortars listed in Table 2 after curing for seven days in a sealed plastic bag at ambient laboratory temperature of 23° C. (73° F.). The compressive strength values for mortars possessing polymer/cement ratios of 0.15, 0.3 and 0.45 are 3684 psi (25 MPa), 3239 psi (22 MPa) and 2611 psi (18 MPa), respectively. Statistical software was utilized for data analysis. One-way ANOVA was used to test the equality of the population means for compressive strength testing of polymer modified mortars at polymer/cement ratios of 0.15, 0.3 and 0.45. Results from ANOVA are: F(2/6)=111.75, p=0.000, pooled standard deviation=0.609 and R2=97.39%. Based upon the F value of 111.75 and corresponding p-value=0.000, if an alpha value of 0.05 is chosen, it is safe to reject the null hypothesis and ultimately conclude that at least two means differ from one another, and this inequality is highly unlikely due to chance. Further “post hoc” statistical analysis utilizing Tukey's Honestly Significant Difference Test assigned the mortar with p/c=0.15 to “A” compressive strength classification, the mortar with p/c=0.3 to “B” compressive strength classification while the mortar with p/c=0.45 has been assigned to “C” compressive strength classification. For the Tukey comparison method, mortars that do not share the same letter strength classification are significantly different.
Table 5 displays formulation information for a rapid setting hydraulic cement mortar with polymer/cement ratio=1/1. Table 6 displays mechanical property performance information for the formulation displayed in Table 5 after curing for 7 days at ambient laboratory temperature of 23° C. and 50% relative humidity. There is an increase in ductile behavior with increase in polymer content per specific volume of microstructure. One mortar with p/c=0.45 displays 8% elongation; whereas, a mortar with p/c=1/1 displays 21% elongation.
TABLE 5
Mortar formulation by mass with
polymer/hydraulic binder ratio 1/1
Hydraulic Binding Agent (g)
500
VAE Polymer Powder (T g = −7° C.) (g)
500
Admixtures (g)
162
Sand (g)
1500
Water (g)
300
TABLE 6
Mechanical property performance characteristics for
mortar formulation displayed in Table 5
Mechanical Property Performance
Mortar with p/c = 1/1
(3 sample average)
ASTM C109 Compressive Strength
2160 psi (14.9 MPa)
ASTM C348 Flexural Strength
1642 psi (11.3 MPa)
ASTM C307 Direct Tensile Strength
584 psi (4 MPa)
% Elongation Direct Tensile Strength (%)
21.3
TABLE 7
Experimental and prophetic mechanical property
information for polymer modified cementitious mortars varying
polymer/cement ratio holding all other constituents constant
p/c = 2/1
p/c = 0.15
p/c = 0.3
p/c = 0.45
p/c = 1/1
(prophetic)
Compressive
3684
3239
2611
2160
1500
Strength (psi)
Uni-axial
692
775
719
584
450
direct tensile
strength
(psi)
% Elongation
4
6
8
21
33
Modulus of
1169
1406
1596
1642
1500
Rupture
(psi)
Behavior
brittle
brittle
somewhat
brittle/
more elastic
brittle
elastic
The information displayed in Table 7 further illustrates the influence of polymer/cement ratio on material toughness.
In FIG. 11 are examples of sample specimens for ASTM C307 uni-axial direct tensile strength testing. Such samples are colloquially referred to as “dog bone” samples in thee art. For testing, grips were attached to each end via clamps at the neck. A universal testing machine pulled the grips apart along a straight line resulting in a clean break at the neck as pictured in FIG. 11 . The % elongation at break is a measure of the distance the grips traveled away from one another as the dog bone sample elongated before reaching its breaking point. For the samples depicted in FIG. 11 as well as those described in Table 8 and FIG. 12 , the only variable in formulations was polymer mass. It is important to note that, while strength varied according to the variable polymer mass, strength is less important than % elongation for various materials such as are described herein. That is, % elongation defines elasticity, and elastic materials elongate before breaking, whereas brittle materials suddenly break in violent fashion. Increases in polymer/cement ratio are related to increases in elongation before the point of breaking, i.e., elongation at break. Such information complements the information provided in the stress/strain diagrams obtained per ASTM C307, which detail the exact distance the grips moved away from one another during the process of breaking the dog bone samples. Each time a dog bone is broken, the universal testing machine provides the stress in psi required to break the sample, and the distance the grips traveled as % elongation.
TABLE 8
Polymer modified cement mortar formulations
EF6-230BPA
AST2-230
AST3-250
Hydraulic Binder (g)
660
660
660
Polymer (g)
100
200
300
Fine Sand (g)
1375
1375
1375
Coarse Sand (g)
125
125
125
Admixtures (g)
5
5
5
Water (g)
230
230
250
With respect to the formulations shown in Table 8, it will be noted that polymer mass was the only variable other than water. The polymer/cement ratio increased from EF6-230 BPA to AST3-250 (0.15→0.3→0.45).
Similarly, with respect to formulations whose performance is depicted in FIG. 12 , it will be noted that increasing polymer content was the only change in mortar formulations: EF6-230BPA (p/c=0.15), AST2-230 (p/c=0.3) and AST3-250 (p/c=0.45). Increasing polymer/cement ratio was responsible for increased elastic behavior, i.e., increased elongation at break. Increased elongation at break means the sample physically got longer before it broke in the middle of the neck as shown in FIG. 11 . The polymer film developed according to a process such as is described herein was observed to be semi-continuous. That is, samples such as those shown in FIG. 11 , upon a 24-hour acid etch, retain the original shape of the dog bone. At high polymer/cement ratios, such an acid etch yields a semi-continuous film having essentially the same dimensions as the original sample specimen, yet with a multiplicity of small lacunae.
TABLE 9
Chart listing caliber and ammunition specifications for testing
ballistic loading according to UL 752
Min
Max
Num-
ve-
ve-
ber
Weight
Weight
locity
locity
of
Rating
Ammunition
(grains)
(grams)
(fps)
(fps)
Shots
Level I
9 mm full metal
124
8
1175
1293
3
copper jacket
with lead core
Level II
0.357 Magnum
158
10.2
1250
1373
3
jacketed lead
soft point
Level
0.44 Magnum
240
15.6
1350
1485
3
III
Lead
Semi-Wadcutter
gas checked
Level
0.30 claiber rifle
180
11.7
2540
2794
1
IV
lead core
soft pont
(.30-06 caliber)
Level V
7.62 mm
150
9.7
2750
3025
1
rifle lead
core full metal
copper jacket
military ball
(0.308 caliber)
Level
9 mm full metal
124
8
1400
1540
5
VI
copper jacket
with lead core
Level
5.56 mm rifle
55
3.56
3080
3383
5
VII
full metal copper
jacket with lead
core (0.223
caliber)
Level
7.62 mm rifle
150
9.7
2750
3025
5
VIII
lead core
full metal
copper jacket
military ball
(0.308 caliber)
Level
0.30-06 caliber
166
10.8
2715
2987
1
IX
rifle, steel core,
lead point filler,
FMJ (APM2)
Level X
0.50 caliber rifle,
709.5
45.9
2810
3091
1
lead core FMCJ
military ball
(M2)
Shotgun
12 Gauge rifled
1
28.3
1585
1744
3
lead slug
ounce
Shotgun
12 Gauge 00
1.5
42
1200
1320
3
buckshot
ounces
(12 pellets)
Table 9 displays a listing of specifications related to caliber and ammunition for testing according to UL 752. FIGS. 13, 14 and 15 demonstrate spall behavior of materials such as are described herein with varying polymer/cement ratios when tested with a 44 magnum handgun utilizing 240 grain lead, semi-wad cutter gas checked ammunition. FIGS. 13, 14 and 15 illustrate blocks of approximate dimension 9 in×12 in×4 in constructed with identical mortars varying polymer/cement ratio. FIGS. 13, 14 and 15 display spall behavior of materials with polymer/cement ratios of approximately 1/7, 5/7 and 7/7, respectively when shot with a Smith and Wesson Model 629 Classic 44 Magnum at a distance of approximately 10 ft (3.05 m). FIG. 13 clearly displays impact markings associated with 3 ricochet bullets with minimal spall. FIG. 14 clearly displays the material with polymer/cement ratio of 5/7 absorbing all 3 bullets into the material microstructure while generating minimal spall or structural damage. Shots 2 and 3 were virtually placed on top of one another in FIG. 14 . FIG. 15 clearly displays the material with polymer/cement ratio of 7/7 absorbing all 3 bullets into the material microstructure while generating minimal spall or structural damage.
FIG. 16 illustrates further testing of the blocks displayed in FIGS. 13, 14 and 15 . FIG. 16 illustrates the higher polymer/cement ratio materials generating less spall when shot 5 times with a 0.223 caliber Ruger Ranch Rifle with 55 grain full metal jacket bullets. FIG. 16 illustrates the block with polymer/cement ratio of 1/7 virtually disintegrating after being shot 3 times with a 44 Magnum and subsequently being shot 5 times with a 0.223 rifle. FIG. 16 is of great significance as it demonstrates the ability of the higher polymer/cement ratio materials to absorb significant amounts of energy in comparison to traditional, brittle cementitious materials.
Every reference cited herein is incorporated fully by reference. To the extent that there be any conflict between the teaching of any reference and that of the instant specification, the teaching of the instant specification shall control.
Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing description. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
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Disclosed is a cementitious product, the product comprising a liquid medium, a hydraulic binding agent, a latex polymer and optionally one or more other components, wherein the direct tensile strength of the product as determined by ASTM C307 is at least 120% of a predicted direct tensile strength of the product per an equation selected from the group consisting of f′dt=0.06*f′c, f′dt=0.07*f′c, f′dt=0.08*f′c and f′dt=0.11*f′c, and wherein the the flexural strength of the product as determined by ASTM C348 is at least 150% of a predicted flexural strength of the product per an equation selected from the group consisting of f′r=0.1*f′c, f′r=0.17*f′c, f′r=9.5*((f′c)^0.5) and f′r=7.5*((f′c)^0.5).
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to methods of blow molding polymeric tubing for stent manufacturing.
[0003] 2. Description of the State of the Art
[0004] This invention relates to radially expandable endoprostheses, which are adapted to be implanted in a bodily lumen. An “endoprosthesis” corresponds to an artificial device that is placed inside the body. A “lumen” refers to a cavity of a tubular organ such as a blood vessel.
[0005] A stent is an example of such an endoprosthesis. Stents are generally cylindrically shaped devices, which function to hold open and sometimes expand a segment of a blood vessel or other anatomical lumen such as urinary tracts and bile ducts. Stents are often used in the treatment of atherosclerotic stenosis in blood vessels. “Stenosis” refers to a narrowing or constriction of the diameter of a bodily passage or orifice. In such treatments, stents reinforce body vessels and prevent restenosis following angioplasty in the vascular system. “Restenosis” refers to the reoccurrence of stenosis in a blood vessel or heart valve after it has been treated (as by balloon angioplasty, stenting, or valvuloplasty) with apparent success.
[0006] The treatment of a diseased site or lesion with a stent involves both delivery and deployment of the stent. “Delivery” refers to introducing and transporting the stent through a bodily lumen to a region, such as a lesion, in a vessel that requires treatment. “Deployment” corresponds to the expanding of the stent within the lumen at the treatment region. Delivery and deployment of a stent are accomplished by positioning the stent about one end of a catheter, inserting the end of the catheter through the skin into a bodily lumen, advancing the catheter in the bodily lumen to a desired treatment location, expanding the stent at the treatment location, and removing the catheter from the lumen.
[0007] In the case of a balloon expandable stent, the stent is mounted about a balloon disposed on the catheter. Mounting the stent typically involves compressing or crimping the stent onto the balloon. The stent is then expanded by inflating the balloon. The balloon may then be deflated and the catheter withdrawn. In the case of a self-expanding stent, the stent may be secured to the catheter via a retractable sheath or a sock. When the stent is in a desired bodily location, the sheath may be withdrawn which allows the stent to self-expand.
[0008] The stent must be able to satisfy a number of mechanical requirements. First, the stent must be capable of withstanding the structural loads, namely radial compressive forces, imposed on the stent as it supports the walls of a vessel. Therefore, a stent must possess adequate radial strength. Radial strength, which is the ability of a stent to resist radial compressive forces, is due to strength and rigidity around a circumferential direction of the stent. Radial strength and rigidity, therefore, may also be described as, hoop or circumferential strength and rigidity.
[0009] Once expanded, the stent must adequately maintain its size and shape throughout its service life despite the various forces that may come to bear on it, including the cyclic loading induced by the beating heart. For example, a radially directed force may tend to cause a stent to recoil inward. Generally, it is desirable to minimize recoil.
[0010] In addition, the stent must possess sufficient flexibility to allow for crimping, expansion, and cyclic loading. Longitudinal flexibility is important to allow the stent to be maneuvered through a tortuous vascular path and to enable it to conform to a deployment site that may not be linear or may be subject to flexure. Finally, the stent must be biocompatible so as not to trigger any adverse vascular responses.
[0011] The structure of a stent is typically composed of scaffolding that includes a pattern or network of interconnecting structural elements often referred to in the art as struts or bar arms. The scaffolding can be formed from wires, tubes, or sheets of material rolled into a cylindrical shape. The scaffolding is designed so that the stent can be radially compressed (to allow crimping) and radially expanded (to allow deployment). A conventional stent is allowed to expand and contract through movement of individual structural elements of a pattern with respect to each other.
[0012] Additionally, a medicated stent may be fabricated by coating the surface of either a metallic or polymeric scaffolding with a polymeric carrier that includes an active or bioactive agent or drug. Polymeric scaffolding may also serve as a carrier of an active agent or drug.
[0013] Furthermore, it may be desirable for a stent to be biodegradable. In many treatment applications, the presence of a stent in a body may be necessary for a limited period of time until its intended function of, for example, maintaining vascular patency and/or drug delivery is accomplished. Therefore, stents fabricated from biodegradable, bioabsorbable, and/or bioerodible materials such as bioabsorbable polymers should be configured to completely erode only after the clinical need for them has ended.
[0014] There are several characteristics that are important for implantable medical devices, such as stents, including high radial strength and good fracture toughness. Some crystalline or semi-crystalline polymers that may be suitable for use in implantable medical devices have potential shortcomings with respect to some of these characteristics, in particular, fracture toughness.
SUMMARY OF THE INVENTION
[0015] Various embodiments of the present invention include a method for fabricating stent comprising: radially deforming a polymer tube for use in fabrication of a stent from the deformed tube, wherein the radial deformation propagates along the tube axis as the tube is heated along the axis, the polymer tube having an internal tube pressure higher than ambient; controlling the propagation rate or the radial deformation rate to provide a selected fracture resistance of a stent fabricated from the tube; and fabricating the stent from the deformed tube.
[0016] Further embodiments of the present invention include a method for fabricating a stent comprising: radially deforming a polymer tube for use in fabrication of a stent from the deformed tube, wherein the radial deformation propagates along the tube axis as the tube is heated along the axis, the polymer tube having an internal tube pressure higher than ambient; controlling a temperature of the polymer tube to provide a selected fracture resistance of the stent fabricated from the tube; and fabricating the stent from the deformed tube.
[0017] Additional embodiments of the present invention include a method for fabricating a stent comprising: increasing an internal pressure of a tube to a deformation pressure; translating a heat source along an axis of the polymer tube to heat the tube to a deformation temperature; allowing the tube to radially expand as the heat source translates along the axis of the polymer tube, wherein the heating of the tube and the increase in pressure allow the tube to radially expand; and controlling one or more process parameters to provide a selected fracture resistance a stent fabricated from the tube, wherein the process parameters are selected from the group consisting of the deformation pressure, the translation rate of the heat source, the deformation temperature; and fabricating the stent from the deformed tube.
[0018] Other embodiments of the present invention include a method for fabricating a stent comprising: determining one or more process parameters of a radial deformation process of a tube to provide a selected fracture resistance of a stent fabricated from the tube, the radial deformation process comprising: increasing an internal pressure of a tube to a deformation pressure; translating a heat source along an axis of the polymer tube to heat the tube to a deformation temperature; allowing the tube to radially expand as the heat source translates along the axis of the polymer tube, wherein the heating of the tube and the increase in pressure allow the tube to radially expand, wherein the process parameters are selected from the group consisting of the deformation pressure, the translation rate of the heat source, the deformation temperature; and fabricating the stent from the deformed tube.
[0019] Further embodiments of the present invention include a method for fabricating a stent comprising: increasing an internal pressure of a polylactide tube to between 120 psi and 130 psi; translating a heat source along an axis of the polymer tube at a translation rate between 0.5 and 0.7 mm/s to heat the tube to between 190° C. and 210° C.; allowing the tube to radially expand as the heat source translates along the axis of the polymer tube, wherein the heating of the tube and the increase in pressure allow the tube to radially expand; and fabricating the stent from the deformed tube.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 depicts a stent.
[0021] FIG. 2 depicts a tube.
[0022] FIGS. 3A-3C depict blow molding of a polymeric tube.
[0023] FIG. 4 depicts a schematic plot of the crystal nucleation rate and the crystal growth rate, and the overall rate of crystallization.
[0024] FIG. 5 depicts experimental results for the R CG of PLLA.
[0025] FIG. 6 is a photograph of a stent.
[0026] FIG. 7 is a graph showing the number of cracks observed in stents made from tubes with different expansion process parameters.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The various embodiments of the present invention relate to methods of fabricating a polymeric stent that have good or optimal toughness and selected mechanical properties along the axial direction or circumferential direction of the stent, or both. The present invention can be applied to devices including, but is not limited to, self-expandable stents, balloon-expandable stents, stent-grafts, and grafts (e.g., aortic grafts).
[0028] For the purposes of the present invention, the following terms and definitions apply:
[0029] The “glass transition temperature,” T g , is the temperature at which the amorphous domains of a polymer change from a brittle vitreous state to a solid deformable or ductile state at atmospheric pressure. In other words, the T g corresponds to the temperature where the onset of segmental motion in the chains of the polymer occurs. When an amorphous or semicrystalline polymer is exposed to an increasing temperature, the coefficient of expansion and the heat capacity of the polymer both increase as the temperature is raised, indicating increased molecular motion. As the temperature is raised the actual molecular volume in the sample remains constant, and so a higher coefficient of expansion points to an increase in free volume associated with the system and therefore increased freedom for the molecules to move. The increasing heat capacity corresponds to an increase in heat dissipation through movement. T g of a given polymer can be dependent on the heating rate and can be influenced by the thermal history of the polymer. Furthermore, the chemical structure of the polymer heavily influences the glass transition by affecting mobility.
[0030] “Stress” refers to force per unit area, as in the force acting through a small area within a plane. Stress can be divided into components, normal and parallel to the plane, called normal stress and shear stress, respectively. Tensile stress, for example, is a normal component of stress applied that leads to expansion (increase in length). In addition, compressive stress is a normal component of stress applied to materials resulting in their compaction (decrease in length). Stress may result in deformation of a material, which refers to a change in length. “Expansion” or “compression” may be defined as the increase or decrease in length of a sample of material when the sample is subjected to stress.
[0031] “Strain” refers to the amount of expansion or compression that occurs in a material at a given stress or load. Strain may be expressed as a fraction or percentage of the original length, i.e., the change in length divided by the original length. Strain, therefore, is positive for expansion and negative for compression.
[0032] “Modulus” may be defined as the ratio of a component of stress or force per unit area applied to a material divided by the strain along an axis of applied force that results from the applied force. For example, a material has both a tensile and a compressive modulus.
[0033] “Stress at peak” is the maximum tensile stress which a material will withstand prior to fracture. Stress at break can also be referred to as the tensile strength. The stress at break is calculated from the maximum load applied during a test divided by the original cross-sectional area.
[0034] “Stress at break” is the tensile stress of a material at fracture.
[0035] “Toughness” is the amount of energy absorbed prior to fracture, or equivalently, the amount of work required to fracture a material. One measure of toughness is the area under a stress-strain curve from zero strain to the strain at fracture. The stress is proportional to the tensile force on the material and the strain is proportional to its length. The area under the curve then is proportional to the integral of the force over the distance the polymer stretches before breaking. This integral is the work (energy) required to break the sample. The toughness is a measure of the energy a sample can absorb before it breaks. There is a difference between toughness and strength. A material that is strong, but not tough is said to be brittle. Brittle substances are strong, but cannot deform very much before breaking.
[0036] A stent can have a scaffolding or a substrate that includes a pattern of a plurality of interconnecting structural elements or struts. FIG. 1 depicts an example of a view of a stent 100 . Stent 100 has a cylindrical shape with an axis 160 and includes a pattern with a number of interconnecting structural elements or struts 110 . In general, a stent pattern is designed so that the stent can be radially compressed (crimped) and radially expanded (to allow deployment). The stresses involved during compression and expansion are generally distributed throughout various structural elements of the stent pattern. The present invention is not limited to the stent pattern depicted in FIG. 1 . The variation in stent patterns is virtually unlimited.
[0037] The underlying structure or substrate of a stent can be completely or at least in part made from a biodegradable polymer or combination of biodegradable polymers, a biostable polymer or combination of biostable polymers, or a combination of biodegradable and biostable polymers. Additionally, a polymer-based coating for a surface of a device can be a biodegradable polymer or combination of biodegradable polymers, a biostable polymer or combination of biostable polymers, or a combination of biodegradable and biostable polymers.
[0038] A stent such as stent 100 may be fabricated from a polymeric tube or a sheet by rolling and bonding the sheet to form a tube. For example, FIG. 2 depicts a tube 200 . Tube 200 is cylindrically-shaped with an outside diameter 205 and an inside diameter 210 . FIG. 2 also depicts an outside surface 215 and a cylindrical axis 220 of tube 200 . In some embodiments, the diameter of the polymer tube prior to fabrication of an implantable medical device may be between about 0.2 mm and about 5.0 mm, or more narrowly between about 1 mm and about 3 mm. Polymeric tubes may be formed by various types of methods, including, but not limited to extrusion or injection molding.
[0039] A stent pattern may be formed on a polymeric tube by laser cutting a pattern on the tube. Representative examples of lasers that may be used include, but are not limited to, excimer, carbon dioxide, and YAG. In other embodiments, chemical etching may be used to form a pattern on a tube.
[0040] The pattern of stent 100 in FIG. 1 varies throughout its structure to allow radial expansion and compression and longitudinal flexure. A pattern may include portions of struts that are straight or relatively straight, an example being a portion 120 . In addition, patterns may include bending elements 130 , 140 , and 150 .
[0041] Bending elements bend inward when a stent is crimped to allow radial compression. Bending elements also bend outward when a stent is expanded to allow for radial expansion. After deployment, a stent is under static and cyclic compressive loads from the vessel walls. Thus, bending elements are subjected to deformation during use. “Use” includes, but is not limited to, manufacturing, assembling (e.g., crimping stent on a catheter), delivery of stent into and through a bodily lumen to a treatment site, and deployment of stent at a treatment site, and treatment after deployment.
[0042] Additionally, stent 100 is subjected to flexure along axis 160 when it is maneuvered through a tortuous vascular path during delivery. Stent 100 is also subjected to flexure when it has to conform to a deployment site that may not be linear.
[0043] There are several mechanical properties that are important for a stent. These include high radial strength, adequate toughness, low recoil, and resistance to physical aging. A stent must have adequate strength, particularly, in the radial direction to withstand structural loads, namely radial compressive forces, imposed on the stent as it supports the walls of a vessel. Radial strength is associated with strength of the stent around the circumferential direction of the stent. In addition, the stent must possess sufficient toughness so that the stent exhibits sufficient flexibility to allow for crimping, expansion, and flexure. A stent should have sufficient toughness so that it is resistant to crack formation, particularly, in high strain regions. Recoil refers to the retraction of a stent radially inward from its deployed diameter.
[0044] A stent can be made in whole or in part of a biodegradable polymer. A biodegradable stent can be configured erode away from an implant site when it is no longer needed. A biodegradable stent allows further surgery or intervention, if necessary, on a treated vessel and reduces the likelihood of late stent thrombosis, a condition in which clots form on the surface of the stent months or years after deployment. Some crystalline or semi-crystalline biodegradable polymers that are glassy or have a glass transition temperature (Tg) above body temperature are particularly attractive as stent materials due to their strength and stiffness at physiological conditions. Such glassy polymers can be absorbed through chemical degradation, such as hydrolysis. Physiological conditions refer to conditions that an implant is exposed to within a human body. Physiological conditions include, but are limited to, human body temperature, approximately 37° C.
[0045] However, the mechanical properties of such polymers may require improvement to be suitable as stent materials. For example, the struts of stent may have to be undesirably large to have radial strength sufficient to support the walls of a vessel. Therefore, the strength of such polymers may need improvement. Additionally, the toughness of such polymers can be lower than desired, in particular, for use in stent applications. For example, polymers such as poly(L-lactide) (PLLA) are stiff and strong, but tend to be brittle under physiological conditions. These polymers can exhibit a brittle fracture mechanism at physiological conditions in which there is little or no plastic deformation prior to failure. A stent fabricated from such polymers can have insufficient toughness for the range of use of a stent. As a result, cracks, particularly in high strain regions, can be induced which can result in mechanical failure of the stent.
[0046] Furthermore, recoil can result from creep and stress relaxation which result from relaxation or rearrangement of polymer chains. Creep refers to the gradual deformation that occurs in a polymeric construct subjected to an applied load. Stress relaxation occurs when deformation (or strain) is constant and is manifested by a reduction in the force (stress) required to maintain a constant deformation
[0047] Physical aging can also be a problem with such semicrystalline polymers. Physical aging, as used herein, refers to densification in the amorphous regions of a semi-crystalline polymer. Densification is the increase in density of a material or region of a material and results from reordering of polymer chains. Densification tends to decrease the fracture toughness of a polymer.
[0048] In general, the mechanical properties of a polymer depend upon its morphology or microstructure. Various embodiments of the present invention include processing a polymeric construct that is a precursor to a stent to obtain desirable or selected mechanical properties of the stent. Such desirable or selected mechanical properties can correspond to a particular structure or morphology. Embodiments of the present invention include adjusting the processing conditions to obtain selected or desirable properties.
[0049] Morphology includes, but is not limited to, crystallinity, molecular orientation of polymer chains, and crystal size. A polymer may be completely amorphous, partially crystalline, or almost completely crystalline. A partially crystalline polymer includes crystalline regions separated by amorphous regions. The degree of crystallinity is the sum of all the crystalline regions. Molecular orientation refers to the relative orientation of polymer chains along a longitudinal or covalent axis of the polymer chains. The orientation can refer to both the orientation of polymer chains the crystalline regions and the amorphous regions.
[0050] The relationship between the morphology and mechanical properties can be of use in alleviating some of the shortcomings of the semi-crystalline polymers mentioned above. In general, the modulus of a polymer increases as crystallinity increases. As mentioned above, a semi-crystalline polymer with a high degree of crystallinity can be brittle and is susceptible to cracking. An amorphous polymer may be more flexible or ductile, but may have insufficient radial strength. Additionally, the size of crystalline regions in a polymer can affect mechanical properties. It is believed that decreasing the size of crystalline regions or domains while maintaining a degree of crystallinity in a polymer increases the fracture toughness of the polymer.
[0051] Furthermore, the strength and toughness of a polymer can be affected by the orientation of polymer chains. The toughness of a semi-crystalline polymer can be increased by inducing orientation of polymer chains in both the crystalline and amorphous regions. In addition, the strength of the polymer is also increased along the direction of preferred orientation.
[0052] It is believed that crystalline domains can act as net points to tie polymer chains in the amorphous regions between the domains. Smaller domains at a given degree of crystallinity result in a greater number of domains and tie molecules, resulting in increased toughness. The strength and toughness of the amorphous regions can be further be increased by inducing orientation in the amorphous regions. It is expected that a higher number of net points and tie molecules with induced orientation can lead to higher strength and fracture toughness.
[0053] Certain embodiments of the present invention include processing a stent precursor construct, such as a polymer tube, to modify the morphology of the polymer in the construct so that the construct has desired or selected properties. It is well known by those skilled in the art that the mechanical properties of a polymer can be modified by applying stress to a polymer. James L. White and Joseph E. Spruiell, Polymer and Engineering Science, 1981, Vol. 21, No. 13. The application of stress can induce molecular orientation along the direction of stress which can modify mechanical properties along the direction of applied stress. Induced orientation in constructs such as polymer tubes can be particularly useful since tubes formed by extrusion tend to possess no or substantially no polymer chain alignment in the circumferential direction. A tube made from injection molding has a relatively low degree of polymer chain alignment in both the axial and circumferential directions.
[0054] In certain embodiments, the processing of the stent precursor construct can include deformation of a polymer tube radially, axially, or both to obtain selected or desirable mechanical properties. The processing can modify structural or morphological characteristics of the polymeric construct including crystallinity, crystal size, and molecular orientation. The processing can include radially deforming a polymer tube through application of an outwardly directed radial force. The radial force can be from an internal pressure of a fluid in the tube that is above ambient pressure. Ambient pressure corresponds to the pressure outside of the tube which is typically at or near atmospheric pressure.
[0055] Furthermore, the deformation can be facilitated by heating the tube prior to the deformation. Additionally, the tube can also be heated prior to and during the deformation of the tube. In some embodiments, the tube can be heated to a temperature above the Tg of the polymer of the tube.
[0056] In further embodiments, the polymeric tube can be axially deformed or stretched. The tube can be axially deformed by applying a tensile force at one end with the other end fixed or applying a tensile force at both ends. The temperature of the tube can be increased to a deformation temperature prior to the deformation of the tube and maintained at the deformation temperature during deformation. The deformation temperature may be in a range at or slightly below the Tg of the polymer of the tube to the melting temperature of the polymer of the tube. “Slightly below” the Tg can refer to temperatures of 5% below the Tg to the Tg of the polymer. The temperature of the tube can also be increased at a constant or nonlinear rate during deformation.
[0057] The degree of radial expansion, and thus induced radial orientation and strength, of a tube can be quantified by a radial expansion (RE) ratio:
[0000]
Outside
Diameter
of
Expanded
Tube
Original
Inside
Diameter
of
Tube
[0000] The RE ratio can also be expressed as a percent expansion:
[0000] % Radial expansion=(RE ratio−1)×100%
[0058] Similarly, the degree of axial extension, and thus induced axial orientation and strength, may be quantified by an axial extension (AE) ratio:
[0000]
Length
of
Extended
Tube
Original
Length
of
Tube
[0059] The AE ratio can also be expressed as a percent expansion:
[0000] % Axial expansion=(AE ratio−1)×100%
[0060] In further embodiments, the deformed tube can be heat set or annealed while the tube is maintained in the deformed state. In such embodiments, the internal pressure in the tube or the axial tension can be at levels that maintain the tube in the deformed state. The deformed tube can also be maintained at the deformation temperature or at a temperature above or below the deformation temperature. The heat setting or annealing can release internal stresses in the polymer. In addition, the heat setting or annealing allows crystallization to continue resulting in further increasing of the crystallinity. During the heat setting or annealing, the polymer chains are allowed to rearrange to approach an equilibrated configuration, relieving internal stresses.
[0061] Additionally, the deformed tube may then be cooled. The tube can be cooled slowly from above Tg to below Tg. Alternatively, the tube can be cooled quickly or quenched below Tg to an ambient temperature. The tube can be maintained at the deformed diameter during cooling.
[0062] In certain embodiments of the present invention, a polymeric tube may be deformed by blow molding. A balloon blowing apparatus may be adapted to radially deform a polymer tube. In blow molding, a tube can be deformed radially by conveying a fluid into the tube which increases the internal pressure in the tube. The polymer tube may be deformed axially by applying a tensile force by a tension source at one end while holding the other end stationary. Alternatively, a tensile force may be applied at both ends of the tube. The tube may be axially extended before, during, and/or after radial expansion.
[0063] In some embodiments, blow molding may include first positioning a tube in a cylindrical member or mold. The mold controls the degree of radial deformation of the tube by limiting the deformation of the outside diameter or surface of the tube to the inside diameter of the mold. The inside diameter of the mold may correspond to a diameter less than or equal to a desired diameter of the polymer tube. Alternatively, the fluid temperature and pressure may be used to control the degree of radial deformation by limiting deformation of the inside diameter of the tube as an alternative to or in combination with using the mold.
[0064] As indicated above, the temperature of the tube can be heated to temperatures above the Tg of the polymer during deformation. The polymer tube may also be heated prior to, during, and subsequent to the deformation. In some embodiments, the tube may be heated by translating a heating source along the cylindrical axis of the tube. As the heat source translates and heats the tube, the radial deformation propagates along the axis of the tube. In other embodiments, in addition to the heat source, the tube may be heated by the mold or the fluid conveyed into the tube to expand the tube. The mold may be heated, for example, by heating elements on, in, and/or adjacent to the mold.
[0065] Certain embodiments may include first sealing, blocking, or closing a polymer tube at a distal end. The end may be open in subsequent manufacturing steps. The fluid, (conventionally a gas such as air, nitrogen, oxygen, argon, etc.) may then be conveyed into a proximal end of the polymer tube to increase the pressure in the tube. The pressure of the fluid in the tube may radially expand the tube.
[0066] Additionally, the pressure inside the tube, the tension along the cylindrical axis of the tube, and the temperature of the tube may be maintained above ambient levels for a period of time to allow the polymer tube to be heat set. Heat setting may include maintaining a tube at a temperature greater than or equal to the Tg of the polymer and less than the Tm of the polymer for a selected period to time. The selected period of time may be between about one minute and about two hours, or more narrowly, between about two minutes and about ten minutes. The polymer tube may then be cooled to below its Tg either before or after decreasing the pressure and/or decreasing tension. Cooling the tube helps insure that the tube maintains the proper shape, size, and length following its formation. Upon cooling, the deformed tube retains the length and shape imposed by an inner surface of the mold.
[0067] FIGS. 3A-C depict a schematic blow molding system 300 which illustrates deforming a polymer tube with blow molding. In some embodiments, a polymer tube for use in manufacturing stent can have a diameter of 1-3 mm. However, the present invention is applicable to polymer tubes less than 1 mm or greater than 3 mm. The wall thickness of the polymer tube can be 0.03-0.06 mm, however, the present invention is application to tubes with a wall thickness less than 0.03 mm and greater than 0.06 mm.
[0068] FIG. 3A depicts an axial cross-section of a polymer tube 301 with an undeformed outside diameter 305 positioned within a mold 310 . Mold 310 limits the radial deformation of polymer tube 301 to a diameter 315 , the inside diameter of mold 310 . Polymer tube 301 may be closed at a distal end 320 . Distal end 320 may be open in subsequent manufacturing steps. A fluid may be conveyed, as indicated by an arrow 325 , into an open proximal end 321 of polymer tube 301 to increase an internal pressure within tube 301 to radially deform tube 301 . A tensile force can be applied at proximal end 321 , a distal end 320 , or both.
[0069] Polymer tube 300 is heated by a nozzle 330 with fluid ports that direct a heated fluid at two circumferential locations of tube 310 , as shown by arrows 335 and 340 . FIG. 3B depicts a radial cross-section showing tube 301 , mold 310 , and nozzle 330 having structural members 360 . Additional fluid ports can be positioned at other circumferential locations of tube 310 . The heated fluid flows around tube 301 , as shown by arrows 355 , to heat mold 310 and tube 301 to a temperature above ambient temperature.
[0070] Nozzle 355 translates along the longitudinal axis of tube 310 as shown by arrows 365 and 367 . As nozzle 330 translates along the axis of mold 310 , tube 301 radially deforms. The increase in temperature of tube 301 and the increased pressure cause deformation of tube 301 , as depicted in FIG. 3C .
[0071] FIG. 3C depicts system 300 with a deforming section 372 and deformed section 370 of tube 301 . Section 372 deforms radially as shown by an arrow 380 . Deformed section 370 has an outside diameter the same as the outside diameter of mold 310 .
[0072] Processing parameters of the above-described deformation process include, but are not limited to, the deformation temperature, deformation pressure (or force), nozzle translation rate, heat setting temperature, and the time of heat setting. It is expected that the deformation rate depends at least upon the deformation pressure, deformation temperature, and heat source or nozzle translation rate. The deformation rate has both a radial component in the radial direction and an axial component corresponding to the propagation rate of the radial deformation along the axis of the tube. The deformation in the radial direction is shown by arrow 380 in FIG. 3C and the axial component is shown by an arrow 382 in FIG. 3C . It is expected that the radial deformation rate has a greater dependence on the deformation pressure and the axial component has a greater dependence on the translation rate of the heat source along the axis of the tube. Since deformation of a polymer is a time dependent process, it is expected that the deformation rate will also affect the morphology and structure of the deformed polymer. The morphology and consequently the mechanical properties of the deformed tube are expected to depend upon the processing parameters.
[0073] Embodiments of the present invention include determining or optimizing processing parameters of a blow molding process of a polymer tube. In such embodiments, the processing parameters are determined or optimized to achieve or provide desired mechanical properties of a stent fabricated from the blow molded or deformed tube. In some embodiments, the processing parameters can be determined or optimized to obtain a selected morphology of the polymer of the deformed tube that provides the desired mechanical properties. Additionally, in such embodiments, the processing parameters include, but are not limited to, the deformation temperature, deformation pressure, and nozzle speed. Further embodiments of the present invention include controlling, adjusting, or modifying processing parameters of a blow molding process of a polymer tube that provide the desired mechanical properties. In these embodiments, a stent may then be fabricated from the blow molded tube.
[0074] In some embodiments, the processing parameters that provide desired mechanical properties can be determined or optimized by blow molding two or more tubes. One or more the processing parameters can be varied so that two or more tubes are blow molded with at least one different processing parameter. Stents can then be fabricated from the tubes and the mechanical properties and performance determined for the stents using known testing techniques. For example, the radial strength and modulus can be determined. The toughness and fracture resistance can be evaluated by examining the fracture and breaking of struts when the stents are expanded to a deployment diameter or greater than a deployment diameter. Additionally, the morphology (e.g., crystallinity, molecular orientation of polymer chains, and crystal size) of the tubes can be determined by known testing techniques, as discussed in examples below.
[0075] Furthermore, the desired mechanical properties can include high radial strength, high toughness, high modulus, and low recoil. A polymer stent fabricated from the polymer tube can have a high resistance to failure upon expansion of the stent. The high resistance to failure can be demonstrated by few or no cracks in struts of a stent or no broken struts upon expansion of the stent to a deployment diameter. In such embodiments, the processing parameters can be modified to change the morphological characteristics, such as crystallinity, molecular orientation of polymer chains, and crystal size.
[0076] In certain embodiments, the axial propagation rate, the radial deformation rate, the deformation temperature, or any combination thereof can be optimized and controlled to provide selected or desired mechanical properties of a stent such as selected fracture resistance. In such embodiments, the axial propagation rate or the radial deformation rate can be controlled or adjusted by the deformation pressure, heat source translation rate, the deformation pressure, or a combination thereof.
[0077] The temperature of the deformation process can be used to control the degree of crystallinity and the size of the crystalline domains. In general, crystallization tends to occur in a polymer at temperatures between Tg and Tm of the polymer. The rate of crystallization in this range varies with temperature. FIG. 4 depicts a schematic plot of the crystal nucleation rate (R N ), the crystal growth rate (R CG ), and the overall rate of crystallization (R CO ). The crystal nucleation rate is the growth rate of new crystals and the crystal growth rate is the rate of growth of formed crystals. The overall rate of crystallization is the sum of curves R N and R CG .
[0078] In certain embodiments, the temperature of the tube during deformation can be controlled to have a crystallization rate that provides a selected degree of crystallization and crystal size distribution. In some embodiments, the temperature can be in a range in which the crystal nucleation rate is larger than the crystal growth rate. For example, as shown in FIG. 4 , the temperature can be in a range as shown by “X”. In such embodiments, the temperature can be in a range at which the crystal nucleation rate is relatively high and the crystal growth rate is relatively low. For example, the temperature can be in a range where the ratio of the crystal nucleation rate to crystal growth rate is 2, 5, 10, 50, 100, or greater than 100. In exemplary embodiments, the temperature can be from about Tg to about 0.6(Tm−Tg)+Tg or from about Tg to about 0.9(Tm−Tg)+Tg.
[0079] Under these conditions, the resulting polymer can have a relatively large number of crystalline domains that are relatively small. As the size of the crystalline domains decreases along with an increase in the number of domains, the fracture toughness of the polymer can be increased reducing or minimizing brittle behavior. By deforming and the polymer tube as described, the size of the crystals can range from less than about 15, less than about 10, less than about 6, less than about 2, or less than about 1 micron.
[0080] FIG. 5 depicts experimental results for the R CG of PLLA. (Eur. Polymer Journal, 2005) In region Y, there is fast nucleation rate and slow crystal growth rate and in region Z, there is slow nucleation rate and fast crystal growth.
[0081] In certain embodiments, the processing parameters can be modified to obtain a morphology corresponding to an amorphous structure having relatively small crystalline domains with polymer chains having a high degree of orientation. The size of the crystalline domains can be minimized by adjusting a temperature in the range X shown in FIG. 5 . A pressure and nozzle speed can also be adjusted to obtain the desired mechanical properties. As shown in the examples below, the deformation pressure and nozzle speed can be adjusted to increase the strength and toughness of the deformed polymer tube.
[0082] Polymers can be biostable, bioabsorbable, biodegradable or bioerodible. Biostable refers to polymers that are not biodegradable. The terms biodegradable, bioabsorbable, and bioerodible are used interchangeably and refer to polymers that are capable of being completely degraded and/or eroded when exposed to bodily fluids such as blood and can be gradually resorbed, absorbed, and/or eliminated by the body. The processes of breaking down and eventual absorption and elimination of the polymer can be caused by, for example, hydrolysis, metabolic processes, bulk or surface erosion, and the like.
[0083] It is understood that after the process of degradation, erosion, absorption, and/or resorption has been completed, no part of the stent will remain or in the case of coating applications on a biostable scaffolding, no polymer will remain on the device. In some embodiments, very negligible traces or residue may be left behind. For stents made from a biodegradable polymer, the stent is intended to remain in the body for a duration of time until its intended function of, for example, maintaining vascular patency and/or drug delivery is accomplished.
[0084] Representative examples of polymers that may be used to fabricate or coat an implantable medical device include, but are not limited to, poly(N-acetylglucosamine) (Chitin), Chitosan, poly(hydroxyvalerate), poly(lactide-co-glycolide), poly(hydroxybutyrate), poly(hydroxybutyrate-co-valerate), polyorthoester, polyanhydride, poly(glycolic acid), poly(glycolide), poly(L-lactic acid), poly(L-lactide), poly(D,L-lactic acid), poly(D,L-lactide), poly(caprolactone), poly(trimethylene carbonate), polyester amide, poly(glycolic acid-co-trimethylene carbonate), co-poly(ether-esters) (e.g. PEO/PLA), polyphosphazenes, biomolecules (such as fibrin, fibrinogen, cellulose, starch, collagen and hyaluronic acid), polyurethanes, silicones, polyesters, polyolefins, polyisobutylene and ethylene-alphaolefin copolymers, acrylic polymers and copolymers other than polyacrylates, vinyl halide polymers and copolymers (such as polyvinyl chloride), polyvinyl ethers (such as polyvinyl methyl ether), polyvinylidene halides (such as polyvinylidene chloride), polyacrylonitrile, polyvinyl ketones, polyvinyl aromatics (such as polystyrene), polyvinyl esters (such as polyvinyl acetate), acrylonitrile-styrene copolymers, ABS resins, polyamides (such as Nylon 66 and polycaprolactam), polycarbonates, polyoxymethylenes, polyimides, polyethers, polyurethanes, rayon, rayon-triacetate, cellulose, cellulose acetate, cellulose butyrate, cellulose acetate butyrate, cellophane, cellulose nitrate, cellulose propionate, cellulose ethers, and carboxymethyl cellulose. Another type of polymer based on poly(lactic acid) that can be used includes graft copolymers, and block copolymers, such as AB block-copolymers (“diblock-copolymers”) or ABA block-copolymers (“triblock-copolymers”), or mixtures thereof.
[0085] Additional representative examples of polymers that may be especially well suited for use in fabricating or coating an implantable medical device include ethylene vinyl alcohol copolymer (commonly known by the generic name EVOH or by the trade name EVAL), poly(butyl methacrylate), poly(vinylidene fluoride-co-hexafluororpropene) (e.g., SOLEF 21508, available from Solvay Solexis PVDF, Thorofare, N.J.), polyvinylidene fluoride (otherwise known as KYNAR, available from ATOFINA Chemicals, Philadelphia, Pa.), ethylene-vinyl acetate copolymers, and polyethylene glycol.
EXAMPLES
[0086] The examples and experimental data set forth below are for illustrative purposes only and are in no way meant to limit the invention. The following examples are given to aid in understanding the invention, but it is to be understood that the invention is not limited to the particular materials or procedures of examples.
Example 1
[0087] The following example describes the adjusting or optimizing of morphology and mechanical properties of expanded PLLA tubes. A commercially available balloon blower or expander was used for radially expanding the polymer tubes. The expander was modified to allow change in morphology at different process conditions. The modified expander includes a displacement control function. The displacement control function allows fabrication of samples of expanded tubing with different mechanical properties from the same source or lot of extruded tubing.
[0088] The effect of three process parameters on the morphology of the polymer tube and mechanical properties of stents was studied. These parameters include the deformation temperature, deformation pressure, and nozzle speed. Tubes were deformed using two different values for each parameter to examine influence of the parameters and different combinations of values of parameters on the properties of the tubes and stents. Deformation runs using three combinations of these values were performed to determine optimal values and combinations parameter values.
[0089] Table 1 lists the values of the deformation temperature and the relative deformation pressure and speed. High and low temperature and pressures and a slow and fast nozzle speeds were used. The different parameter values are expected to provide different crystallization rates, radial deformation rates, and axial deformation rates. The high temperature provides a higher crystallization rate compared to the low temperature. The high pressure provides a higher radial deformation rate compared to the low pressure. The fast nozzle speed provides a higher axial deformation rate than the slow nozzle speed.
[0000]
TABLE 1
Values of deformation temperature and deformation pressure
Temp (° C.)
Relative Pressure
Relative Speed
200
low
slow
300
high
fast
[0090] Tubes were deformed using three different combinations or options of the parameter values shown in Table 1. Table 2 lists the three combinations of the processing parameter values.
[0000]
TABLE 2
Combinations or options of processing parameters.
Option
Temp
Pressure
Speed
1
High
High
Fast
2
Low
High
Slow
3
Low
Low
Slow
[0091] Polymer tubes were deformed at the processing conditions for each option. The tubes were then made into stents for mechanical testing. FIG. 6 is a photograph of a stent having the pattern of the stent used in the testing. The stents were designed for 3.0 mm deployment. Stents were aged by heat-setting in an oven at 40° C. for 16 hours. Stent were deployed to 3.5 mm and 4.0 mm in order to induce failure during testing. This testing technique allows the observation of stent failure early at extreme conditions. The stents were fabricated from tubes with the same dimension of expanded tubing, with different processing conditions used to expand the tubes.
[0092] The toughness of the stents were assessed through comparison of the number of cracks observed in the stent samples at zero time point when deployed at diameters of 3.5 mm and 4 mm. FIG. 7 is a graph showing the number of cracks observed in stents made from tubes processed using options 2 and 3. Two different crack size ranges were determined: “>25%” refers to cracks greater than 25% of the strut width. “>50%” refers to cracks greater than 50% of the strut width. As shown in FIG. 7 , the number of cracks for option 3 stents for each crack size is less than the corresponding crack size for option 2 stents.
[0093] Table 3 shows crack data for stents made from tubes processed with option 1 and option 2 parameters. The results for four stents at each option are shown. Table 4 shows that for stents deployed to 3.5 mm, the cumulative number of cracks for option 2 stents at each crack number range is less than for option 1 stents. No broken struts were observed at 3.5 mm for any of the stents tested. The option 1 stents had more broken struts at 4 mm deployment than the option 2 stents.
[0000]
TABLE 3
Crack counts for stents made from tubes processed with option 1 (300° C.)
and option 2 (200° C.) processing parameters.
Crack >
Crack >
Broken
Broken
Expansion
25% at
50% at
Strut at
Strut at
Stent
Temp (° C.)
3.5 mm
3.5 mm
3.5 mm
4.0 mm
B-1
200
0
0
0
0
B-2
200
2
0
0
2
B-3
200
0
0
0
0
B-4
200
2
0
0
0
C-1
300
4
2
0
10
C-2
300
4
1
0
7
C-3
300
2
1
0
4
C-4
300
3
1
0
5
[0094] Table 4 summarizes the comparison of the three processing options shown in Table 2. As shown, option 3 provides the best mechanical performance which is demonstrated in FIG. 7 and Table 3. The appearance of the deformed tubes is also affected by processing conditions. Option 3 parameters result in a tube having a clear appearance. It is believed that option 3 provides the best mechanical performance in part because the lower temperature results in the formation of a greater number of smaller crystalline domains. Additionally, option 3 is better because the slower deformation rate facilitates the development of an oriented molecular structure with reduced internal stresses.
[0000]
TABLE 4
Summary of results for options 1, 2, and 3.
Stent
Morphology
Option
Temp
Pressure
Speed
Appearance
Performance
Development
1
High
High
Fast
Clear
Worse
Faster crystallization temp.
Faster deformation
Higher crystallinity,
lower amorphous
orientation
2
Low
High
Slow
Hazy
Better
Faster deformation in
radial direction
Lower crystallization rate
3
Low
Low
Slow
Clear
Best
Slower deformation rate
Lower crystallization rate
Example 2
[0095] Table 5 depicts desirable processing conditions for expanding a tube that provide good stent performance for three stent materials. The first material is 100% PLLA. The second is a PLLA/elastomeric polymer blend that includes PLLA with a dispersed elastomeric block copolymer to increase toughness. The elastomeric copolymer is (CL-co-GA)-b-PLLA. The (CL-co-GA) blocks form a dispersed elastomeric phase and the PLLA block increases adhesion between the PLLA matrix and the elastomeric phase. The third material is the polymer blend with dispersed bioceramic nano-particles.
[0000]
TABLE 5
Desirable tube expansion parameters for three stent materials.
Temp
Pressure
Speed
Stent
Run
(° F.)
(psi)
(mm/s)
Appearance
Performance
Polymer
1
200 ± 20
130 ± 20
0.6
Clear
Good
100% PLLA
2
190 ± 10
120 ± 20
0.6
Hazy
Good
PLLA/Elastomeric
copolymer Blend
3
190 ± 10
120 ± 20
0.6
Hazy
Good
PLLA/Elastomeric
copolymer/nano-particles
Example 3
[0096] The following example describes a study on the effect of deformation temperature on morphology for expanded PLLA tubes. Table 6 lists the four samples that were studied. Stent samples 1 and 4 were made from tubes expanded at 200° C. and samples 2 and 3 were made from tubes expanded at 300° C.
[0000]
TABLE 6
Tube dimension, expansion ratio and appearance of stent samples.
Before Expansion
After Expansion
ID
OD
ID
OD
RE %
Appearance
#1
0.017
0.0565
0.073
0.0845
300%
Transparent
#2
0.016
0.06
0.082
0.094
412%
Turbid
#3
0.014
0.06
0.082
0.094
486%
Turbid
#4
0.024
0.074
0.125
0.137
421%
Turbid
[0097] Differential scanning calorimetry (DSC) was used to determine the crystallinity of each of the samples. Table 7 lists the enthalpy of crystallization, enthalpy of melting, and % crystallinity for each sample. As expected, the % crystallinity is lower for samples 1 and 4 than for samples 2 and 3 due the higher crystal growth rate at the higher temperature.
[0000]
TABLE 7
DSC results for expanded tubing.
∇Hc (J/g)
∇Hm (J/g)
Xc(%)
#1
3.332
51.17
51.4%
#2
1.285
49.87
52.2%
#3
0.8725
49.85
52.7%
#4
1.576
48.19
50.1%
[0098] Wide angle x-ray scattering (WAXS) was used to determine the crystal size of the in the expanded tubes. The tube samples were scanned both horizontally along the tube axis and vertically perpendicular to the tube axis. Table 8 shows the results of the WAXS for the four stent samples. As expected, samples 1 and 4 had smaller crystal sizes than samples 2 and 3 since the crystal growth rate is smaller at the lower temperature.
[0000]
TABLE 8
Crystal Size of samples from X-ray
Crystal
Sample
Linewidth
2θ
size/nm
#1
H
0.83261
16.456
9.95
V
0.7590
16.414
10.9
#2
H
0.58275
16.457
14.2
V
0.49191
16.477
16.8
#3
H
0.60212
16.509
13.8
V
0.56963
16.546
14.5
#4
H
0.95572
16.427
8.67
V
0.73321
16.478
11.3
[0099] While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications can be made without departing from this invention in its broader aspects. Therefore, the appended claims are to encompass within their scope all such changes and modifications as fall within the true spirit and scope of this invention.
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Methods to expand polymer tubing with desirable or optimum morphology and mechanical properties for stent manufacture and fabrication of a stent therefrom are disclosed.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a divisional of application Ser. No. 07/284,171 filed Dec. 14, 1988 now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to a method for the lubrication of a parison for use in a blow molding process. Utilization of the present invention permits blow molding of containers having elliptical horizontal cross sections that have a high aspect ratio.
The production of containers through the use of a blow molding process is widely practiced in the container manufacturing industry. The first step in this process consists of extruding or, preferably, injecting a molten substance into a mold cavity. Upon hardening, a thick walled hollow object commonly known as a preform or a parison is produced. This parison is then brought to a temperature conducive to blow molding and placed in a blow mold. A high pressure gas or mixture of gasses such as air is then injected into the interior of the parison, causing the parison to rapidly expand until it contacts the walls of the blow mold cavity. The final form of the container is produced by the walls of the blow mold cavity cooling the substance and preventing further expansion of the substance.
Many substances can be used in a blow molding process, but glass and thermoplastics are most commonly used in the container manufacturing industry. High density polyethylene, polypropylene, and polyvinyl chloride based plastics are all suitable for use in a blow molding process. For some thermoplastics, such polyethylene terepthalate, an additional step of biaxially orienting the thermoplastic by stretching the parison can provide superior clarity, drop resistance, and tensile strength to the finished product.
However, blow molding is not an ideal method for producing certain types of finished articles that have shapes whose cross section is not substantially circular. Containers having elliptical cross sections of high aspect ratio are difficult to produce using this method because the parison walls freeze against the mold walls upon contact, stopping any flow of material from the frozen areas of the parison to those areas of the parison that are still expanding due to air pressure. As a result, the walls of the container are abnormally thick in those areas that first contact the mold near the minor axis of the mold, and abnormally thin in those areas near the major axis of the mold.
A further problem is the migration of the crystallized plastic sprue point when thermoplastics such as polyethylene terepthalate are used. When the parison is injection molded, the plastic nearest the injection sprue is abnormally hot compared to the rest of the plastic. The heat in the sprue area causes polyethylene terepthalate to crystallize into a more brittle form. This crystallized plastic, sometimes known as a sprue artifact, constitutes an unavoidable weak point in the finished product. However, the possibility of failure at the point of crystallization represented by the sprue artifact can be minimized by appropriate design of the finished product. If the sprue artifact is centered at the bottom of the finished product, and protected from direct contact with other objects by raised ridges or feet, the possibility of failure due to impact is signnificantly reduced.
When products having a substantially circular cross section are blow molded, the sprue artifact remains generally centered in a protected position because the blown parison nearly simultaneously contacts the walls of the blow mold cavity. However, if the mold has a high aspect ratio elliptical horizontal cross section, the sprue artifact can migrate to areas outside the protective structures due to non-uniform thinning caused by freezing of the plastic to the mold walls. If the sprue artifact migrates outside of the protected area, the finished product is useless because of the high risk of stress induced container failure at the sprue artifact point.
Several methods have unsuccessfully been attempted to remedy the problem of wall thinning and migration of the sprue artifact. Varying blow pressures, changing mold temperatures and changing mold profiles have failed to alleviate the problems associated with blow molding containers having a high aspect ratio elliptical, horizontal cross sections. More substantial changes, such as forming a blow mold from nickel impregnated with a slippery fluorocarbon compound such as Teflon have also failed to prevent wall thinning due to premature freezing contact with the mold walls. Other alternatives such as designing preforms with elliptical shapes could work in certain situations, but the cost of retooling to handle and properly orient variant shapes can be prohibitive, especially when low volume or marginally profitable production runs are contemplated.
SUMMARY OF THE INVENTION
The present invention provides a method for preventing the premature freezing contact of a blown parison with the walls of the mold cavity, thereby reducing the differences in wall thickness and sprue artifact migration caused by the freezing contact. This is accomplished by the addition of a barrier layer between the walls of a mold cavity and a parison. The barrier layer prevents the premature cooling and consequent freezing of the parison material to the walls of the mold cavity, and permits the continued flow of material toward the expanding sections of a blown parison.
Many barrier materials are suitable for use in this invention. A barrier material should not significantly interact chemically or physically with either the parison material or the walls of the mold cavity, should remain stable under the temperatures typically encountered during the blow molding process, and should not present a hazard to human health. Preferred embodiments of a barrier material for the present invention are lubricants capable of being applied as a surficial liquid to the wall of the parison. A most preferred embodiment is a liquid such as AP-5, certified for use as a lubricant by the FDA.
A lubricant acting as a barrier material can be applied in a number of ways. One suitable embodiment for application of a lubricant is realized by an apparatus for dipping a suspended parison into a bath of the lubricant barrier material. The wetted parison is then transferred to the proper position in the blow mold for subsequent processing. A drip tray or drip wiping pad can be provided to ensure that excess lubricant is returned to the lubricant bath, assuring economical use of the lubricant barrier material and preventing spread of the lubricant fluid to inappropriate areas.
An alternative embodiment contemplates the use of spray devices to evenly disperse the lubricant barrier material on the surface of a parison. The region about the spray area should have suitable protective barriers, such as walls, fume hoods, or forced drafts in order to prevent unwanted dispersion of the lubricant. The use of spray application is not recommended however for those applications involving containers for foods or beverages. The problem of contamination of the interior of the parison by airborne spray particles of the lubricant makes sanitary use of spray devices problematical unless the application takes place while the mouth of the parison is closed such as by a parison handling device.
A preferred embodiment of the invention that can be used with virtually any blow molding machine without expensive modifications to the blow mold cavity area, and with little danger of contamination utilizes a contoured application pad. An application pad, composed a material suitable for applying a liquid coating of the lubricant to a parison, is constructed so as to conform to the desired areas of the parison the contoured application pad can be constructed in either one piece or a plurality of separate pieces. The application pad can also have either a fixed structure or be rotatable.
Means for supplying the lubricant barrier material to the application pad are also necessary. For limited use, this can be as simple as pouring the lubricant barrier material directly on the applicant pad before use. For long term applications, an automatic system of supplying lubricant barrier material to the application pad is recommended, such as using a rotatable application pad that at some point during rotation encounters a bath of the liquid. Such a rotatable application pad can be rotatably driven either by frictive contact with parisons laterally moving across the edges of the application pad, or by a drive mechanism that causes rotation of the application pad. For continuous use, the amount of lubricant barrier material applied to the parison should not exceed the amount of lubricant barrier material supplied to the application pad.
It is accordingly an object of the present invention to provide a method for the application of a barrier material that prevents the premature freezing of a blown parison to the walls of a blow mold cavity.
It is a further object of this invention to provide a method for the blow molding of objects having a a high aspect ratio elliptical horizontal cross section.
Another object of this invention is to provide a method for the prevention of sprue migration in blown plastic parisons.
It is also an object of this invention to provide a method for ensuring that a blown container has substantially uniform wall thickness, with no abnormal thinning or thickening of the walls.
Another object of this invention is to provide a method for applying a lubricant that acts as a barrier material between a parison and the walls of a blow mold.
BRIEF DESCRIPTION OF THE DRAWINGS
Various features and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed descriptions of preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived. The detailed description particularly refers to the accompanying figures in which:
FIG. 1 is a view of a blown container and a dotted line indicating the size and position of a parison before the container is blown;
FIG. 2 is a horizontal cross sectional view of a blow mold showing the original placement of the parison and two representative positions of the parison walls during expansion;
FIG. 3 is a partial cross sectional view of a fixed application pad contoured to fit a parison transported in contact with the application pad;
FIG. 4 is view of a contoured, mechanically driven rotary application pad;
FIG. 5 is a view of a rotary application pad, friction driven by the transport of parisons attached to a separate conveyor;
FIG. 6 is a side view of a friction driven rotary application pad; and
FIG. 7 is a view of a dipping application bath.
DETAILED DESCRIPTION OF THE INVENTION
A side view of a blown container 12 is shown in FIG. 1. The size and position of a parison 10 in relation to the blown container 12 is indicated by the dotted line. The shape of the blown container 12 is similar to the shape of containers commonly used in the food industry to contain salad dressings of various kinds. The upper region of the blown container 12 has screw threading 13 suited for accepting a corresponding threaded cap (not shown) in order to seal the container. A horizontal cross section taken in the region about screw threading 13, such as indicated by line a-b, would reveal a substantially circular wall structure of the blown container 12 in that area. A horizontal cross section taken in the lower regions of the blown container 12, such as indicated by line c-d, would reveal a substantially elliptical wall structure having a high aspect ratio. The particular shape of the illustrated container 12 is not intended to limit the invention, but rather is intended merely to illustrate an example of a container having a high aspect ratio cross section.
For the purposes of this invention, aspect ratio is defined as the resultant of the division of the length of the major axis by the length of the minor axis of a container. The container shape does not have to exactly correspond to a rigorously defined geometrical ellipse, but can be any closed figure. For example, as those skilled in the art can appreciate, a substantially rectangular figure has a well defined aspect ratio equal to the length of the rectangle divided by its width. A similar aspect ratio value can be derived for irregular or varying container cross sectional shapes by determining the average minimal and maximal lengths of the cross section of the container. A blown container 12 has a low aspect ratio if the aspect ratio is between about 1.0 to 1.1. A low aspect ratio ellipse may be considered to be substantially circular. A blown container 12 has a moderate aspect ratio if it has a ratio of major axis length to minor axis length of between about 1.1 to 1.7. A high aspect ratio blown container 12 has an aspect ratio more than about 1.7. By utilization of the term "aspect ratio" no limitation is set on the variety of shapes of containers that can be injection blow molded by the use of this invention.
The blow molding process may be understood by referring to FIG. 2, which shows a cross section of a blow mold 14 used to form the blown container 12 shown in FIG. 1. The horizontal cross section of the blow mold 14 shown in FIG. 2 is the portion that forms the corresponding part of blown container 12 indicated by line c-d. FIG. 2 also shows a cross sectional view of parison 10 in a mold cavity 15 that corresponds to the parison 10 indicated by the dotted lines in FIG. 1.
The blow molding process involves the fixed placement of the parison 10 in the mold cavity 15 formed by the blow mold 14. High pressure air is injected into the interior of parison 10, causing the parison to expand. The wall of parison 10 thins during this expansion, as can be seen by noting the relative wall thicknesses of parison 10 before expansion, and the parison at later times, as illustrated by parison 10a and parison 10b. The expansion is ideally uniform so that the wall thickness of the end product, the blown container 14, is also uniform. If the wall thickness is not substantially uniform, the blown container is potentially useless because of the high probability of containment failure in any thin wall sections. Even if adequate wall thickness is maintained, a non-uniformity of wall thickness could entail unsightly optical distortions that would render the blown container 14 unsuitable for use.
A common cause of non-uniformity in wall thickness of high aspect ratio containers such as blown container 12 can be attributed to the freezing contact of the expanding plastic material of parison 10 with the mold wall 16. Upon direct contact with the mold wall 16 the plastic material of parison 10a freezes, changing from a semi-fluid plastic state to a glassy or partially crystallized state. That portion of the material which is frozen is effectively removed from the amount of material available to continue expansion, since only non-frozen plastic material is capable of expansion. As the parison 10a continues to expand due to internal air pressure, still more material is frozen by direct contact with the mold wall 16, further diminishing the amount of still semi-fluid plastic material that can expand in the mold cavity 15. The end result is a blown container 12 that has abnormally thick walls in the areas near the intersection of the minor axis and the wall of the blown container 12, which came in first contact with the mold wall 16, and abnormally thin walls near the intersection of major axis and the wall of the blown container 12.
The present invention alleviates the problem of wall thinning due to freezing of the material comprising parison 10 by the placement of a barrier layer (not shown in FIG. 2) between the parison 10 and the mold wall 16. A preferred embodiment of a barrier layer is a liquid lubricant that does not significantly react either physically or chemically with either the material composing parison 10 or the mold wall 16. A more preferred embodiment is a liquid lubricant safe for use with foods or beverages, such as silicon lubricants or edible oils. A most preferred embodiment of a barrier material is a liquid lubricant such as AP 5, which does not leave a sticky residue that could necessitate periodic cleaning of the blow mold 14.
Various methods can be used to coat desired areas of the parison 10 with a lubricant prior to placement of the parison 10 in the blow mold 14. A simple method contemplates the use of a wicking application pad 18, contoured to match the surface profile of the areas of a parison 10 which are to be coated with a lubricant 22 for use as a barrier material. A conveyor system laterally transports the parison 10 so that contact with the contoured areas of wicking application pad 18 is momentarily maintained, permitting the transfer of lubricant 22 to predetermined areas of parison 10. The wicking application pad 18 is constructed of an absorbent material that has a wicking uptake of lubricant 22 contained in lubricant container 20 sufficient to ensure a continual supply of lubricant 22 to the contoured surface of application pad 18.
An alternative embodiment for application of a lubricant to a parison 10 involves the use of a rotating application pad 28 as illustrated in FIG. 4. The rotating application pad 28 is contoured to match the parison 10 surface in the desired areas for coating with a lubricant 22. A rotating drive means 26 is used to cause rotation of the rotating application pad 28. The rotating application pad 28 is supported for rotation by an application pad support 30 acting as an axle means for the rotating application pad 28. A rotating drive 32, which can be an electric motor or other device capable of imparting a rotary force, causes rotation of a drive pulley 34. This rotary motion is communicated by means of a drive belt 36 to the rotating application pad 28. The revolution speed of rotating drive 32 can be determined so that partial, single or multiple revolutions of the rotating application pad 28 occur when the parison 10 is in contact during its lateral transport across the contoured surface of the rotating application pad 28. In operation, the rotating application pad 28 is partially immersed in a bath of lubricant 22.
Alternative embodiments of a rotating drive are also contemplated. For example, direct mounting of the rotating application pad 28 on a drive pulley 34 without an intermediary drive pulley would also ensure rotation of the rotating application pad 28. Other means of causing rotation of a rotating application pad 28 can be readily envisaged by those skilled in the art.
The use of a rotating drive means 26 is not necessary for the operation of this invention. FIG. 5 illustrates a rotating application pad 28 that is not driven by a rotating drive means 26. The rotating application pad 28 is axially supported by an application pad support 30 that permits free rotation of the rotating application pad 28. The lower portion of the rotating application pad 28 is immersed in a bath of lubricant 22. The frictional forces generated by the substantially tangential transport of a parison 10 by parison conveyor 24 act to rotate the rotating application pad 28 in such a manner that a continuous supply of lubricant 22 is transferred to application pad 28, and from there the lubricant 22 is applied to parison 10. A side view of a rotatable application pad 28 that is not driven is illustrated in FIG. 6. The use of a conveyor belt to tangentially move multiple parisons across the contoured surface of the rotatable application pad 28 is shown.
However, application pads are not a necessary part of this invention. Alternative means of applying a barrier material such as lubricant 22 to a parison are contemplated. Spray devices are well suited for high speed continuous coating purposes, such as are envisioned for operation of the present invention but pose significant problems in terms of control of over spray as previously discussed. In the alternative, dipping methods such as that illustrated in FIG. 7 could suffice to coat the desired areas of a parison 10 with a lubricant 22. In FIG. 7, a parison conveyor 24 having a dipping section 32, dips a parison into a bath of the lubricant 22 before transport of the parison 10 to a blow mold (not shown).
As shown in FIGS. 3-7, the parison has a circular vertical wall ending in a closed rounded bottom portion. The coating is applied to at least the closed bottom rounded bottom portion. The vertical extent of the coating on the parison is only a minor portion of the entire length of the parison. In fact, this minor portion is significantly less than half the vertical extent of the parison.
It is contemplated that the previously described method will have diverse embodiments adapted for particular uses or environments. The particular embodiments previously described are not intended to limit the scope of the invention, and it is intended that the following claims will encompass alternative and equivalent embodiments of the invention.
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A method for enhancing the uniformity of wall thickness of an article having a high aspect ratio horizontal cross section and produced from a parison in a blow molding process whereby a barrier layer is applied to a selected area of the outer surface of each parison prior to its introduction into the blow molding apparatus, the barrier layer being effective to prevent premature freezing of the blown parison upon contact with a wall of the blow molding apparatus. The barrier layer application apparatus includes a generally contoured pad coupled to a supply of the barrier material, the pad being situated to contact a selected portion of each parison prior to its introduction into the blow molding apparatus.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to golf balls incorporating covers formed from polyurethane and/or polyurea compositions which demonstrate light-stability and shear-resistance/durability.
BACKGROUND OF THE INVENTION
[0002] Multi-piece solid golf balls having a core, cover with a casing layer disposed there between are popular today in the golf industry. The core is made commonly of a rubber material such as natural and synthetic rubbers, styrene butadiene, polybutadiene, cis-polyisoprene, or trans-polyisoprene. Often, the casing layer is made of an olefin-based ionomer resin that imparts hardness to the ball. These ionomer acid copolymers contain inter-chain ionic bonding, and are generally made of an α-olefin such as ethylene and a vinyl comonomer having an acid group such as methacrylic, acrylic acid, or maleic acid. Metal ions such as sodium, lithium, zinc, and magnesium are used to neutralize the acid groups in the copolymer. Commercially available olefin-based ionomer resins are used in different industries and include numerous resins sold under the trademarks, Surlyn® (available from DuPont), Iotek® (available from ExxonMobil), Amplify IO® (available from Dow Chemical) and Clarix® (available from A. Schulman). Olefin-based ionomer resins are available in various grades and identified based on the type of base resin, molecular weight, and type of metal ion, amount of acid, degree of neutralization, additives, and other properties. The cover of conventional golf balls are made from a variety of materials including olefin-based ionomers, polyamides, polyesters, and thermoplastic and thermoset polyurethane and polyurea elastomers.
[0003] In recent years, there has been high interest in using thermoset, castable polyurethanes (and polyureas) to make cores, casings (or intermediate layer), and/or cover layers. Basically, polyurethane compositions contain urethane linkages formed by reacting an isocyanate group (—N═C═O) with a hydroxyl group (OH). Polyurethanes are produced by the reaction of a multi-functional isocyanate with a polyol, optionally in the presence of a catalyst and other additives. The chain length of the polyurethane prepolymer is extended by reacting it with a hydroxyl-terminated curing agent.
[0004] Polyurea compositions, which are distinct from the above-described polyurethanes, also can be formed. In general, polyurea compositions contain urea linkages formed by reacting an isocyanate group (—N═C═O) with an amine group (NH or NH 2 ). The chain length of the polyurea prepolymer is extended by reacting the prepolymer with an amine curing agent. Hybrid compositions containing urethane and urea linkages also may be produced. For example, a polyurea/urethane hybrid composition may be produced when a polyurea prepolymer is reacted with a hydroxyl-terminated curing agent. In another example, when a polyurethane prepolymer is reacted with amine-terminated curing agents during the chain-extending step, any excess isocyanate groups in the prepolymer will react with the amine groups in the curing agent. The resulting polyurethane composition contains urethane and urea linkages and may be referred to as a polyurethane/urea hybrid as discussed further below.
[0005] Golf ball covers made from polyurethane and polyurea compositions are generally known in the industry. In recent years, polyurethane and polyurea cover materials have become more popular, because they provide the golf ball covers with a desirable combination of “hard” and “soft” features. The relative hardness of the cover protects the ball from being cut, abraded, and otherwise damaged. In addition, such harder-covered golf balls generally reach a higher velocity when struck by a club. As a result, such golf balls tend to travel a greater distance, which is particularly important for driver shots off the tee. Meanwhile, the relative softness of the cover provides the player with a better “feel” when he/she strikes the ball with the club face. The player senses more control over the ball as the club face makes impact. Such softer-covered balls tend to have better playability. The softer cover allows players to place a spin on the ball and better control its flight pattern. This is particularly important for approach shots near the green. Polyurethane and polyurea covered golf balls are described in the patent literature, for example, U.S. Pat. Nos. 5,334,673; 5,484,870; 6,476,176; 6,506,851; 6,867,279; 6,958,379; 6,960,630; 6,964,621; 7,041,769; 7,105,623; 7,131,915; and 7,186,777.
[0006] As discussed above, isocyanates with two or more functional groups are essential components in producing polyurethane and polyurea polymers. These isocyanate materials can be referred to as multi-functional isocyanates. Such isocyanates can be referred to as monomers or monomeric units, because they can be polymerized to produce polymeric isocyanates containing two or more monomeric isocyanate repeat units.
[0007] Aromatic isocyanates are normally used for several reasons including their high reactivity and cost benefits. Examples of conventional aromatic isocyanates include, but are not limited to, toluene 2,4-diisocyanate (TDI), toluene 2,6-diisocyanate (TDI), 4,4′-methylene diphenyl diisocyanate (MDI), 2,4′-methylene diphenyl diisocyanate (MDI), polymeric methylene diphenyl diisocyanate (PMDI), p-phenylene diisocyanate (PDI), m-phenylene diisocyanate (PDI), naphthalene 1,5-diisocynate (NDI), naphthalene 2,4-diisocyanate (NDI), p-xylene diisocyanate (XDI), and homopolymers and copolymers thereof. The aromatic isocyanates are able to react with the hydroxyl or amine compounds and form a durable and tough polymer having a high melting point. The resulting polyurethane or polyurea material generally has good mechanical strength and cut/shear resistance.
[0008] However, one disadvantage with using aromatic isocyanates is the polymeric reaction product tends to have poor light stability and may discolor upon exposure to light, particularly ultraviolet (UV) light. Because aromatic isocyanates are used as a reactant, some aromatic structures may be found in the reaction product. UV light rays can cause quinoidation of the benzene rings resulting in yellow discoloration. Hence, UV light stabilizers are commonly added to the formulation, but the covers may still discolor or develop a yellowish appearance over prolonged exposure to sunlight. Thus, golf balls are normally painted with a white paint or other desirable color and then covered with a transparent coating to protect the ball's appearance.
[0009] In a second approach, aliphatic isocyanates are used to form the prepolymer. Examples of aliphatic isocyanates include, but are not limited to, isophorone diisocyanate (IPDI), 1,6-hexamethylene diisocyanate (HDI), 4,4′-dicyclohexylmethane diisocyanate (“H 12 MDI”), and homopolymers and copolymers thereof. These aliphatic isocyanates can provide polyurethane and polyurea materials having generally good light stability. However, such polymers tend to have reduced mechanical strength and cut/shear-resistance.
[0010] As discussed above, golf ball covers having good light stability are needed. One objective of this invention is to develop a golf ball incorporating a cover having good light stability and meanwhile not sacrificing important mechanical properties such as shear-resistance/durability. Accordingly, it would be beneficial to develop polyurethane and/or polyurea compositions possessing such desirable properties. The present invention addresses and solves these needs.
SUMMARY OF THE INVENTION
[0011] Thus, a golf ball of the invention comprises: a core; a casing layer surrounding the core; and a cover layer surrounding the casing layer and being formed from a cover composition PC that is produced by a reaction of a prepolymer and a chain extender, wherein the prepolymer is formed from the reaction product of: (i) an isocyanate comprising an allophanate (“ICA”) and having an average NCO functionality in the range of 1.9 to 2.8 and (ii) a polyol-containing component; and wherein the chain extender is selected from the group consisting of amine-terminated chain extenders, hydroxyl-terminated chain extenders, and mixtures thereof. By the term, “NCO functionality in the range of 1.9 to 2.8,” it is meant that the polyisocyanates have an average of 1.9 to 2.8 NCO groups per molecule.
[0012] In another embodiment, a golf ball of the invention comprises a core; a casing layer surrounding the core; and a cover layer surrounding the casing layer and being formed from a cover composition AC that is produced by a reaction of a prepolymer and a chain extender, wherein the prepolymer is formed from the reaction product of: (1) an isocyanate comprising an allophanate (“ICA”) and having an average NCO functionality in the range of 1.9 to 2.8 and (ii) an amine-containing component; and wherein the chain extender is selected from the group consisting of amine-terminated chain extenders, hydroxyl-terminated chain extenders, and mixtures thereof.
[0013] In one embodiment, the ICA comprises a reaction product of hexamethylene diisocyanate (HDI), at least one monoalcohol, and a bismuth-containing catalyst to form an isocyanate comprising an allophanate. In one embodiment, the monoalcohol is selected from the group consisting of: ethoxylated C 12 -C 14 alcohols, ethoxylated C 16 -C 18 alcohols, and ethoxylated C 10 -C 16 alcohols.
[0014] In one embodiment, the ICA has an average NCO functionality in the range of from about 1.9 to about 2.1. In another embodiment, the ICA has an average NCO functionality in the range of from about 1.9 to about 2.3. In yet another embodiment, the ICA has an average NCO functionality in the range of from about 1.9 to about 2.5. In still another embodiment, the ICA has an average NCO functionality in the range of from about 1.9 to about 2.7. In a different embodiment, the ICA has an average NCO functionality in the range of from about 2.0 to about 2.3. In an alternative embodiment, the ICA has an average NCO functionality in the range of from about 2.0 to about 2.2.
[0015] In one embodiment, the ICA has an average equivalent weight of from about 200 to about 350. In another embodiment, the ICA has an average equivalent weight of from about 200 to about 240. In yet another embodiment, the ICA has an average equivalent weight of from about 210 to about 300. In still another embodiment, the ICA has an average equivalent weight of from about 275 to about 340. In a different embodiment, the ICA has an average equivalent weight of from about 301 to about 330. In an alternative embodiment, the ICA has an average equivalent weight of from about 320 to about 330. In a particular embodiment, the ICA has an average equivalent weight of about 325.
[0016] Non-limiting examples of suitable ICA's include Tolonate®X FLO 100, a two functional HDI based allophonate available from Vencorex and DESMODUR®XP2580 available from Bayer Material Science.
[0017] In one embodiment, the prepolymer has an average equivalent weight of from about 420 to about 840. In another embodiment, the prepolymer has an average equivalent weight of from about 420 to about 700, In yet another embodiment, the prepolymer has an average equivalent weight of from about 450 to about 650. In still another embodiment, the prepolymer has an average equivalent weight of from about 475 to about 625. In an alternative embodiment, the prepolymer has an average equivalent weight of from about 500 to about 600. In a different embodiment, the prepolymer has an average equivalent weight of from about 550 to about 575.
[0018] In one embodiment, the amine-terminated chain extender is selected from the group consisting of 4,4′-diamino-diphenylmethane; 3,5-diethyl-(2,4- or 2,6-)toluenediamine; 3,5-dimethylthio-(2,4- or 2,6-)toluenediamine; 3,5-(1,4- or 2,6-)toluenediamine: 2,2′-dichloro-3,3′,5,5′-tetraethyl-4,4′-diamino-diphenylmethane; polytetramethyleneglycol-di(p-aminobenzoate); 4,4′-bis(sec-butylamino)-dicyclohexylmethane; and mixtures thereof.
[0019] In one embodiment, the hydroxyl-terminated chain-extender is selected from the group consisting of ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polytetramethylene ether glycol, polyethylene propylene glycol, polyoxypropylene glycol, 2-methyl-1,3-propanediol, 1,4-butanediol, 2-methyl-1,4-butanediol, and mixtures thereof.
[0020] Cover compositions PC, AC or blends thereof have many advantages including improved light-stability and shear resistance/durability and may be incorporated in a wide range of different golf ball constructions for achieving tailored compression, “feel,” and spin. In one embodiment of a golf ball of the invention, the core has a surface hardness H of from about 50 Shore C to about 90 Shore C and a center hardness CH of from about 50 Shore C to about 90 Shore C; the casing layer has a surface hardness A of from about 45 Shore D to about 80 Shore D; and the cover has a surface hardness B of from about 65 Shore C to about 90 Shore C.
[0021] In one embodiment, H is greater than CH. In another embodiment, CH is greater than H. In yet another embodiment H and CH are substantially the same.
[0022] In one embodiment, the core may be a single core, comprising a substantially homogenous composition and having a geometric center and an outer surface. Alternatively, the core may comprise a center and at least one outer core layer formed about the center, typically called a “dual core” arrangement. In the “dual core” arrangement, surface hardness H is an outer surface hardness of the outermost core layer.
[0023] In another embodiment, CH is from about 65 Shore C to about 75 Shore C, H is from about 65 Shore C to about 75 Shore C, A is from about 60 Shore D to about 75 Shore D, and B is from about 75 Shore C to about 88 Shore C. In yet another embodiment, CH is from about 68 Shore C to about 72 Shore C. H is from about 65 Shore C to about 75 Shore C, A is from about 64 Shore D to about 69 Shore D, and B is from about 80 Shore C to about 84 Shore C. In still another embodiment, CH is from about 69 Shore C to about 71 Shore C, H is from about 65 Shore C to about 75 Shore C, A is from about 65 Shore D to about 68 Shore D and B is from about 81 Shore C to about 83 Shore C.
[0024] Additional examples of golf balls of the invention incorporating cove compositions PC and/or AC formed from an ICA are as follows. In one construction, CH is from about 45 Shore C to about 55 Shore C, H is from about 75 Shore C to about 85 Shore C, A is from about 65 Shore D to about 75 Shore D, and B is from about 77 Shore C to about 83 Shore C. In another embodiment, CH is from about 48 Shore C to about 52 Shore C, H is from about 78 Shore C to about 82 Shore C, A is from about 68 Shore D to about 72 Shore D, and B is from about 78 Shore C to about 82 Shore C. In yet another example, CH is from about 70 Shore C to about 74 Shore C, is from about 84 Shore C to about 88 Shore C, A is from about 66 Shore D to about 70 Shore D, and B is from about 79 Shore C to about 83 Shore C. In still another embodiment, CH is from about 63 Shore C to about 67 Shore C. is from about 86 Shore C to about 90 Shore C, A is from about 65 Shore D to about 75 Shore D, and B is from about 79 Shore C to about 83 Shore C. In a different embodiment, CH is from about 48 Shore C to about 52 Shore C, H is from about 84 Shore C to about 89 Shore C, A is from about 63 Shore D to about 66 Shore D, and B is from about 79 Shore C to about 83 Shore C.
[0025] The USGA has established a maximum weight of 1.62 ounces (45.93 g) for golf balls. For play outside of USGA rules, the golf balls can be heavier. In one preferred embodiment, the weight of the multi-layered core is in the range of about 28 to about 38 grams. Also, golf balls made in accordance with this invention can be of any size, although the USGA requires that golf balls used in competition have a diameter of at least 1.68 inches. For play outside of United States Golf Association (USGA) rules, the golf balls can be of a smaller size. Normally, golf balls are manufactured in accordance with USGA requirements and have a diameter in the range of about 1.68 to about 1.80 inches. However, it is envisioned that golf balls of the invention may also have a diameter of greater than 1.80 inches.
[0026] In a golf ball of the invention, the cover has a thickness of 0.010 inches (in.) or greater. In one embodiment, the cover has a thickness of from about 0.020 in. to about 0.050 in. In another embodiment, the cover has a thickness of from about 0.015 in. to about 0.030 in. In yet another embodiment, the cover has a thickness of from about 0.020 in. to about 0.040 in. In still another embodiment, the cover has a thickness of from about 0.030 in. to about 0.050 in. In an alternative embodiment, the cover has a thickness of from about 0.10 in. to about 0.025 in. In a different embodiment, the cover has a thickness is greater than about 0.050 in.
[0027] In one embodiment of a golf ball of the invention, the core has a diameter of from about 1.26 inches to about 1.60 inches, the cased core has a diameter of from about 1.580 inches to about 1.640 inches, and the cover has a thickness of from about 0.020 inches to about 0.050 inches.
[0028] It is contemplated that the core and cased core may have any diameter, which when combined with the thickness of the cover, produces a finished golf ball having a compression of from about 40 to about 120, or from about 65 to about 110, or from about 60 to about 100. For example, in one embodiment, the core comprises a center having a diameter of from 0.100 inches to 1.100 inches and an outer core layer having a thickness of from 0.200 inches to 1.200 inches. In another embodiment, the core is a single core having an outer diameter of about 1.51 inches to about 1.59 inches and having an outer surface and a geometric center.
[0029] In one embodiment, a golf ball of the invention has a coefficient of restitution (COR) of at least about 0.780. In another embodiment, a golf ball of the invention has a COR of at least about 0.790. In yet another embodiment, a golf ball of the invention has a COR of at least about 0.800. In still another embodiment, a golf ball of the invention has a COR of at least about 0.810.
[0030] In one embodiment, the outer core layer is an intermediate layer. The outer core layer/intermediate layer may be formed from a thermoplastic composition selected from the group consisting of ionomers; polyesters; polyester-ether elastomers; polyester-ester elastomers; polyamides; polyamide-ether elastomers, and polyamide-ester elastomers; polyurethanes, polyureas, and polyurethane-polyurea hybrids and mixtures thereof. The intermediate layer may also be formed from a thermoset composition selected from the group consisting of polyurethanes, polyureas, and polyurethane-polyurea hybrids, epoxies, and mixtures thereof.
[0031] In one construction, the golf ball includes a polybutadiene core, a casing layer formed about the core and comprising an ionomer resin, and a cover layer surrounding the casing layer formed from at least one of cover composition PC and AC. Of course, golf balls made in accordance with this invention may have various constructions. For example, the cover may comprise one or more layers. In an embodiment wherein the cover comprises at least two layers, at least one of the cover layers comprises the cover composition. In a preferred embodiment, the outermost cover layer comprises the cover composition since the cover composition has good light stability and is a durable material.
[0032] In yet another embodiment, a method for making a golf ball of the invention comprises: providing a core; providing a casing layer about the core; and forming a cover layer about the casing layer, the cover layer being formed from a cover composition PC that is produced by a reaction of a prepolymer and a chain extender, wherein the prepolymer is formed from the reaction product of: (i) an isocyanate comprising an allophanate (“ICA”) and having an average NCO functionality in the range of 1.9 to 2.8 and (ii) a polyol-containing component; and wherein the chain extender is selected from the group consisting of amine-terminated chain extenders, hydroxyl-terminated chain extenders, and mixtures thereof.
[0033] In still another embodiment, a method for making a golf ball of the invention comprises: providing a core; providing a casing layer about the core; and forming a cover layer about the casing layer, the cover layer being formed from cover composition AC that is produced by a reaction of a prepolymer and a chain extender, wherein the prepolymer is formed from the reaction product of: (i) an isocyanate comprising an allophanate (“ICA”) and having an average NCO functionality in the range of 1.9 to 2.8 and (ii) an amine-containing component; and wherein the chain extender is selected from the group consisting of amine-terminated chain extenders, hydroxyl-terminated chain extenders, and mixtures thereof.
[0034] In a golf ball of the invention, the resulting cover has a flexural modulus of about 10,000 psi or greater, or a flexural modulus of about 15,000 psi or greater, or a flexural modulus of about 20,000 psi or greater, as measured in accordance with ASTM method D-790. In other embodiments, the cover of a golf ball of the invention has a flexural modulus of from about 10,000 psi to about 50,000 psi, or from about 10,000 psi to about 30,000 psi, or from about 10,000 psi to about 20,000 psi.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] The following prophetic examples illustrate some of the benefits provided by a golf ball of the invention over conventional golf balls. A golf ball of the invention incorporating a cover formed from cover compositions PC and/or AC possesses desirable color stability and shear durability. In this regard, TABLE I below displays the formulations, and TABLE II displays the properties, for one inventive golf ball cover Ex. 1 and three comparative prophetic golf ball covers Comp. Ex. 1, Comp. Ex. 2 and Comp. Ex. 3:
[0000]
TABLE 1
Golf Ball Layer
Formulation
Ex. 1
Comp. Ex. 1
Comp. Ex. 2
Comp. Ex. 3
Tolonate XFLO 100 1
62.92
0
0
0
(Aliphatic)
Desmodur N-3400 2
0
0
35.1
0
(Aliphatic)
Desmodur N-3200 3
0
0
0
33.41
(Aliphatic)
Mondur M 4
0
23.57
0
0
(Aromatic)
PTMEG 2000 5
18.71
59.75
50.11
51.8
Ethacure 100-LC 6
14.79
0
11.21
11.21
Ethacure 300 7
0
13.11
0
0
TiO2 Pigment
3.58
3.57
3.58
3.58
Dispersion 8
1 Tolonate X FLO 100 is a two functional HDI based allophonate available from Vencorex.
2 Desmodur N-3400 is an HDI based dimer/trimer available from Bayer Material Science.
3 Desmodur N-3200 is an HDI based biuret available from Bayer Material Science.
4 Mondur M is 4,4′-MDI available from Bayer Material Science.
5 PTMEG 2000 is polytetramethylene ether glycol of an average molecular weight of 2000 g/mol. available from Invista, BASF, and Diaren Chemical for example.
6 Ethacure 100-LC is diethyltoluene diamine sold by Albemarle.
7 Ethacure 300 is dimethylthiotoluene diamine sold by Albemarle.
8 TiO 2 pigment dispersion is 56% weight loading of TiO 2 in a long chain triol from PolyOne.
[0036] As is shown in TABLE I above, prophetic covers Ex. 1, Comp. Ex. 1, Comp. Ex. 2 and Comp. Ex. 3 are notably different in that cover Ex. 1 is formed from a two functional HDI based allophonate, whereas cover Comp. Ex. 1 is formed from aromatic 4,4′-MDI, and covers Comp. Ex. 2 and Comp. Ex. 3 are multi-component aliphatic polyisocyanates. Otherwise, each of the examples includes a diamine, TiO 2 pigment, and polytetramethylene ether glycol.
[0037] As demonstrated in TABLE II below, a golf ball formed from a cover composition as disclosed and claimed herein is superior as favorably simultaneously possessing and displaying both good light stability and good shear resistance/durability:
[0000]
TABLE II
Characteristic Tested
Ex. 1
Comp. Ex. 1
Comp. Ex. 2
Example 3
Light Stability
Good
Poor
Good
Good
Shear Durability
Good
Good
Fair
Poor
[0038] In contrast, each of the comparative covers is deficient with respect to either light stability or shear durability. Specifically, the aromatic 4,4′-MDI-based cover of Comp. Ex. 1 demonstrates poor light stability, the aliphatic polyisocyanate of cover Comp. Ex. 2 demonstrates only fair shear durability, and the aliphatic polyisocyanate of Comp. Ex. 3 demonstrates poor shear durability.
[0039] Regarding light stability, one of ordinary skill in the art would recognize that it is important to have a cover composition that retains its color with the passage of time. That is, its color remains similar to the initial material color. The color instability caused by both thermo-oxidative degradation and photodegradation typically results in a “yellowing” or “browning” of the polyurethane layer, an undesirable characteristic for urethane compositions are to be used in the covers of golf balls.
[0040] It is well known to one of ordinary skill in the art that the human visual system, which consists of rods that are sensitive to lightness and darkness (white and black, respectively), and cones that respond to color, can be simulated using mathematical models. All existing models derive values from a visible spectrum of a material that can be obtained from a color spectrometer (or colorimeter), that measures the intensity of reflected light (for opaque samples) in the region of the electromagnetic spectrum visible to humans (approximately 400 to 740 nm).
[0041] The CIELCh and CIELAB systems are standard color systems well known in the art of color and appearance to describe the effective “color” of an object. The differences in color between a reference and a test specimen can easily be expressed in terms of the CIELCh or CIELAB values which indicate both magnitude and direction of color difference. Therefore, either the CIELCh or CIELAB systems can be used to measure the color of the polyurethane compositions of the invention. The CIELCh scale separates the “color” of a sample into three parameters on a cylindrical polar coordinate system. In the CIELCh system, L* defines the darkness or lightness, (black and white) component of a sample. For example, an L* value of 100 is pure white, or completely reflective at all wavelengths, whereas an L* value of 0 is pure black, or absorbing all wavelengths of light. C*, however, is a measure of chroma (saturation) and is a vector distance from the center (L* axis) of the color space. Hue (h°) is the third parameter and is represented as an angle ranging from 0° to 360°, where 0°=red, 90°, yellow 180°=green, and 270°=blue.
[0042] It has been determined that, as an unpainted golf ball cover ages during normal usage due to exposure to UV light, the L* values decrease (become darker) and the C* values increase. The hue tends to remain near 90° (i.e., yellow), and may drift slightly higher into the greenish yellow or slightly lower into the reddish yellow. This is a relatively subtle and less visually perceptible change than the increase in chroma, C*. Since the C* increase is essentially traveling along a hue angle of 90°, a larger C* value, in this case, can be thought of as more yellow. Thus, for the purposes of this invention, it is desirable to minimize the initial C* value (less yellow) of the unpainted cover and also inhibit or prevent C* increase over time, the C* rate of increase, or preferably both, due to exposure to UV radiation, for example. It is also desirable to maximize the initial L* (towards white) value and inhibit or prevent its decrease towards black over time due to exposure to UV or other radiation having a similarly disadvantageous effect on the appearance of golf balls.
[0043] Table II above reveals that the cover materials of golf balls Ex. 1, Comp. Ex. 2 and Comp. Ex. 3 may exhibit good color retention and therefore, color change occurs at a favorably slower rate than the material of Comp. Ex. 2.
[0044] Shear resistance is a golf ball's ability to withstand the shear force applied to a ball when hit with a golf club and/or iron. When the grooves on the striking surface of a golf club and/or iron impact a golf ball in a downward oblique swing causing it to slide upward across the face, and immediately forcibly propelled in an outbound trajectory from, the particular club face, the shear force applied to the golf ball cover often produces cuts or abrasion marks on the surface of the cover material of the golf ball. The shear resistance of each golf ball may be evaluated by any procedure known in the art for evaluating durability. For example, low handicap golfers can be used to repeatedly hit a golf ball upon which any damage to the cover is evaluated and rated. TABLE I above demonstrates that inventive cover composition Ex. 1 and comparative golf ball cover Comp. Ex. 1 exhibit good shear resistance, whereas cover compositions Comp. Ex. 2 and Comp. Ex. 3 do not.
[0045] Cores in a golf ball of the invention may be single cores or multi-layered cores. A golf ball of the invention may also display a hardness gradient. In a preferred embodiment, the core hardness gradient as specified herein, measured radially outward from core geometric center to outer surface may be positive, negative or zero (substantially the same hardness). Cores may have a hardness gradient defined by hardness measurements made at the center of the inner core and radially outward towards the outer surface, typically at 2-mm increments. As used herein, the terms “negative” and “positive” refer to the result of subtracting the hardness value at the innermost portion of the component being measured (e.g., the center of a solid core or an inner core in a dual core construction; the inner surface of a core layer; etc.) from the hardness value at the outer surface of the component being measured (e.g., the outer surface of a solid core; the outer surface of an inner core in a dual core; the outer surface of an outer core layer in a dual core, etc.). For example, if the outer surface of a solid core has a lower hardness value than the center (i.e., the surface is softer than the center), the hardness gradient will be deemed a “negative” gradient (a smaller number−a larger number=a negative number).
[0046] The core may be made from a composition including at least one thermoset base rubber, such as a polybutadiene rubber, cured with at least one peroxide and at least one reactive co-agent, which can be a metal salt of an unsaturated carboxylic acid, such as acrylic acid or methacrylic acid, a non-metallic coagent, or mixtures thereof. Preferably, a suitable antioxidant is included in the composition. An optional soft and fast agent (and sometimes a cis-to-trans catalyst), such as an organosulfur or metal-containing organosulfur compound, can also be included in the core formulation.
[0047] Other ingredients that are known to those skilled in the art may be used, and are understood to include, but not be limited to, density-adjusting fillers, process aides, plasticizers, blowing or foaming agents, sulfur accelerators, and/or non-peroxide radical sources. The base thermoset rubber, which can be blended with other rubbers and polymers, typically includes a natural or synthetic rubber. A preferred base rubber is 1,4-polybutadiene having a cis structure of at least 40%, preferably greater than 80%, and more preferably greater than 90%. Examples of desirable polybutadiene rubbers include BUNA® CB22 and BUNA® CB23, commercially available from LANXESS Corporation; UBEPOL® 360L and UBEPOL® 150L and UBEPOL-BR rubbers, commercially available from UBE Industries, Ltd. of Tokyo, Japan; BUDENE 1208, 1207, commercially available from Goodyear of Akron, Ohio; and CB BUNA® 1203G1, 1220, and 1221, commercially available from Dow Chemical Company; Europrene® NEOCIS® BR 40 and BR 60, commercially available from Polimeri Europa; and BR 01, BR 730, BR 735, BR 11, and BR 51, commercially available from Japan Synthetic Rubber Co., Ltd; and KARBOCHEM® ND40, ND45, and ND60, commercially available from Karbochem.
[0048] The base rubber may also comprise high or medium Mooney viscosity rubber, or blends thereof. A “Mooney” unit is a unit used to measure the resistance to flow of raw or unvulcanized rubber. The viscosity in a “Mooney” unit is equal to the torque, measured on an arbitrary scale, on a disk in a vessel that contains rubber at a temperature of 100° C. and rotates at two revolutions per minute. The measurement of Mooney viscosity is defined according to ASTM D-1646.
[0049] The Mooney viscosity range is preferably greater than about 40, more preferably in the range from about 40 to about 80 and more preferably in the range from about 40 to about 60. Polybutadiene rubber with higher Mooney viscosity may also be used, so long as the viscosity of the polybutadiene does not reach a level where the high viscosity polybutadiene adversely interferes with the manufacturing machinery. It is contemplated that polybutadiene with viscosity less than 65 Mooney can be used with the present invention.
[0050] In one embodiment of the present invention, golf ball cores made with mid- to high-Mooney viscosity polybutadiene material exhibit increased resiliency (and, therefore, distance) without increasing the hardness of the ball. Such cores are soft, i.e., compression less than about 60 and more specifically in the range of about 50-55. Cores with compression in the range of from about 30 about 50 are also within the range of this preferred embodiment.
[0051] Commercial sources of suitable mid- to high-Mooney viscosity polybutadiene include LANXESS CB23 (Nd-catalyzed), which has a Mooney viscosity of around 50 and is a highly linear polybutadiene. If desired, the polybutadiene can also be mixed with other elastomers known in the art, such as other polybutadiene rubbers, natural rubber, styrene butadiene rubber, and/or isoprene rubber in order to further modify the properties of the core. When a mixture of elastomers is used, the amounts of other constituents in the core composition are typically based on 100 parts by weight of the total elastomer mixture.
[0052] In one preferred embodiment, the base rubber comprises an Nd-catalyzed polybutadiene, a rare earth-catalyzed polybutadiene rubber, or blends thereof. If desired, the polybutadiene can also be mixed with other elastomers known in the art such as natural rubber, polyisoprene rubber and/or styrene-butadiene rubber in order to modify the properties of the core. Other suitable base rubbers include thermosetting materials such as, ethylene propylene diene monomer rubber, ethylene propylene rubber, butyl rubber, halobutyl rubber, hydrogenated nitrile butadiene rubber, nitrile rubber, and silicone rubber.
[0053] Thermoplastic elastomers (TPE) may also be used to modify the properties of the core layers, or the uncured core layer stock by blending with the base thermoset rubber. These TPEs include natural or synthetic balata, or high trans-polyisoprene, high trans-polybutadiene, or any styrenic block copolymer, such as styrene ethylene butadiene styrene, styrene-isoprene-styrene, etc., a metallocene or other single-site catalyzed polyolefin such as ethylene-octene, or ethylene-butene, or thermoplastic polyurethanes (TPU), including copolymers. Other suitable TPEs for blending with the thermoset rubbers of the present invention include PEBAX®, which is believed to comprise polyether amide copolymers, HYTREL@, which is believed to comprise polyether ester copolymers, thermoplastic urethane, and KRATON®, which is believed to comprise styrenic block copolymers elastomers. Any of the TPEs or TPUs above may also contain functionality suitable for grafting, including maleic acid or maleic anhydride.
[0054] Additional polymers may also optionally be incorporated into the base rubber. Examples include, but are not limited to, thermoset elastomers such as core regrind, thermoplastic vulcanizate, copolymeric ionomer, terpolymeric ionomer, polycarbonate, polyamide, copolymeric polyamide, polyesters, polyvinyl alcohols, acrylonitrile-butadiene-styrene copolymers, polyarylate, polyacrylate, polyphenylene ether, impact-modified polyphenylene ether, high impact polystyrene, diallyl phthalate polymer, styrene-acrylonitrile polymer (SAN) (including olefin-modified SAN and acrylonitrile-styrene-acrylonitrile polymer), styrene-maleic anhydride copolymer, styrenic copolymer, functionalized styrenic copolymer, functionalized styrenic terpolymer, styrenic terpolymer, cellulose polymer, liquid crystal polymer, ethylene-vinyl acetate copolymers, polyurea, and polysiloxane or any metallocene-catalyzed polymers of these species.
[0055] Suitable polyamides for use as an additional polymeric material in compositions within the scope of the present invention also include resins obtained by: (1) polycondensation of (a) a dicarboxylic acid, such as oxalic acid, adipic acid, sebacic acid, terephthalic acid, isophthalic acid, or 1,4-cyclohexanedicarboxylic acid, with (b) a diamine, such as ethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, or decamethylenediamine, 1,4-cyclohexanediamine, or m-xylylenediamine; (2) a ring-opening polymerization of cyclic lactam, such as -caprolactam or Ω-laurolactam; (3) polycondensation of an aminocarboxylic acid, such as 6-aminocaproic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, or 12-aminododecanoic acid; or (4) copolymerization of a cyclic lactam with a dicarboxylic acid and a diamine. Specific examples of suitable polyamides include NYLON 6, NYLON 66, NYLON 610, NYLON 11, NYLON 12, copolymerized NYLON, NYLON MXD6, and NYLON 46.
[0056] Suitable peroxide initiating agents include dicumyl peroxide; 2,5-dimethyl-2,5-di(t-butylperoxy) hexane; 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne; 2,5-dimethyl-2,5-di(benzoylperoxy)hexane; 2,2′-bis(t-butylperoxy)-di-iso-propylbenzene; 1,1-bis(t-butylperoxy)-3,3,5-trimethyl cyclohexane; n-butyl 4,4-bis(t-butyl-peroxy)valerate; t-butyl perbenzoate; benzoyl peroxide; n-butyl 4,4′-bis(butylperoxy) valerate; di-t-butyl peroxide; or 2,5-di-(t-butylperoxy)-2,5-dimethyl hexane, lauryl peroxide, t-butyl hydroperoxide, α-α bis(t-butylperoxy)diisopropylbenzene, di(2-t-butyl-peroxyisopropyl)benzene, di-t-amyl peroxide, di-t-butyl peroxide. Preferably, the rubber composition includes from about 0.25 to about 5.0 parts by weight peroxide per 100 parts by weight rubber (phr), more preferably 0.5 phr to 3 phr, most preferably 0.5 phr to 1.5 phr. In a most preferred embodiment, the peroxide is present in an amount of about 0.8 phr. These ranges of peroxide are given assuming the peroxide is 100% active, without accounting for any carrier that might be present. Because many commercially available peroxides are sold along with a carrier compound, the actual amount of active peroxide present must be calculated. Commercially-available peroxide initiating agents include DICUP™ family of dicumyl peroxides (including DICUP™ R, DICUP™ 40C and DICUP™ 40KE) available from ARKEMA. Similar initiating agents are available from AkroChem, Lanxess, Flexsys/Harwick and R.T. Vanderbilt. Another commercially-available and preferred initiating agent is TRIGONOX™ 265-50B from Akzo Nobel, which is a mixture of 1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane and di(2-t-butylperoxyisopropyl)benzene. TRIGONOX™ peroxides are generally sold on a carrier compound.
[0057] Suitable reactive co-agents include, but are not limited to, metal salts of diacrylates, dimethacrylates, and monomethacrylates suitable for use in this invention include those wherein the metal is zinc, magnesium, calcium, barium, tin, aluminum, lithium, sodium, potassium, iron, zirconium, and bismuth. Zinc diacrylate (ZDA) is preferred, but the present invention is not limited thereto. ZDA provides golf balls with a high initial velocity. The ZDA can be of various grades of purity. For the purposes of this invention, the lower the quantity of zinc stearate present in the ZDA the higher the ZDA purity. ZDA containing less than about 10% zinc stearate is preferable. More preferable is ZDA containing about 4-8% zinc stearate. Suitable, commercially available zinc diacrylates include those from Cray Valley. The preferred concentrations of ZDA that can be used are about 10 phr to about 40 phr, more preferably 20 phr to about 35 phr, most preferably 25 phr to about 35 phr. In a particularly preferred embodiment, the reactive co-agent is present in an amount of about 29 phr to about 31 phr.
[0058] Additional preferred co-agents that may be used alone or in combination with those mentioned above include, but are not limited to, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, and the like. It is understood by those skilled in the art, that in the case where these co-agents may be liquids at room temperature, it may be advantageous to disperse these compounds on a suitable carrier to promote ease of incorporation in the rubber mixture.
[0059] Antioxidants are compounds that inhibit or prevent the oxidative breakdown of elastomers, and/or inhibit or prevent reactions that are promoted by oxygen radicals. Some exemplary antioxidants that may be used in the present invention include, but are not limited to, quinoline type antioxidants, amine type antioxidants, and phenolic type antioxidants. A preferred antioxidant is 2,2′-methylene-bis-(4-methyl-6-t-butylphenol) available as VANOX® MBPC from R.T. Vanderbilt. Other polyphenolic antioxidants include VANOX® T, VANOX® L, VANOX® SKT, VANOX® SWP, VANOX® 13 and VANOX® 1290.
[0060] Suitable antioxidants include, but are not limited to, alkylene-bis-alkyl substituted cresols, such as 4,4′-methylene-bis(2,5-xylenol); 4,4′-ethylidene-bis-(6-ethyl-m-cresol); 4,4′-butylidene-bis-(6-t-butyl-m-cresol); 4,4′-decylidene-bis-(6-methyl-m-cresol); 4,4′-methylene-bis-(2-amyl-m-cresol); 4,4′-propylidene-bis-(5-hexyl-m-cresol); 3,3′-decylidene-bis-(5-ethyl-p-cresol); 2,2′-butylidene-bis-(3-n-hexyl-p-cresol); 4,4′-(2-butylidene)-bis-(6-t-butyl-m-cresol); 3,3′-4(decylidene)-bis-(5-ethyl-p-cresol); (2,5-dimethyl-4-hydroxyphenyl) (2-hydroxy-3,5-dimethylphenyl) methane; (2-methyl-4-hydroxy-5-ethylphenyl) (2-ethyl-3-hydroxy-5-methylphenyl) methane; (3-methyl-5-hydroxy-6-t-butylphenyl) (2-hydroxy-4-methyl-5-decylphenyl)-n-butyl methane; (2-hydroxy-4-ethyl-5-methylphenyl) (2-decyl-3-hydroxy-4-methylphenyl)butylamylmethane; (3-ethyl-4-methyl-5-hydroxyphenyl)-(2,3-dimethyl-3-hydroxy-phenyl)nonylmethane; (3-methyl-2-hydroxy-6-ethylphenyl)-(2-isopropyl-3-hydroxy-5-methyl-phenyl)cyclohexylmethane; (2-methyl-4-hydroxy-5-methylphenyl) (2-hydroxy-3-methyl-5-ethylphenyl)dicyclohexyl methane; and the like.
[0061] Other suitable antioxidants include, but are not limited to, substituted phenols, such as 2-tert-butyl-4-methoxyphenol; 3-tert-butyl-4-methoxyphenol; 3-tert-octyl-4-methoxyphenol; 2-methyl-4-methoxyphenol; 2-stearyl-4-n-butoxyphenol; 3-t-butyl-4-stearyloxyphenol; 3-lauryl-4-ethoxyphenol; 2,5-di-t-butyl-4-methoxyphenol; 2-methyl-4-methoxyphenol; 2-(1-methycyclohexyl)-4-methoxyphenol; 2-t-butyl-4-dodecyloxyphenol; 2-(1-methylbenzyl)-4-methoxyphenol; 2-t-octyl-4-methoxyphenol; methyl gallate; n-propyl gallate; n-butyl gallate; lauryl gallate; myristyl gallate; stearyl gallate; 2,4,5-trihydroxyacetophenone; 2,4,5-trihydroxy-n-butyrophenone; 2,4,5-trihydroxystearophenone; 2,6-ditert-butyl-4-methylphenol; 2,6-ditert-octyl-4-methylphenol; 2,6-ditert-butyl-4-stearylphenol; 2-methyl-4-methyl-6-tert-butylphenol; 2,6-distearyl-4-methylphenol; 2,6-dilauryl-4-methylphenol; 2,6-di(n-octyl)-4-methylphenol; 2,6-di(n-hexadecyl)-4-methylphenol; 2,6-di(1-methylundecyl)-4-methylphenol; 2,6-di(1-methylheptadecyl)-4-methylphenol; 2,6-di(trimethylhexyl)-4-methylphenol; 2,6-di(1,1,3,3-tetramethyloctyl)-4-methylphenol; 2-n-dodecyl-6-tert butyl-4-methylphenol; 2-n-dodecyl-6-(1-methylundecyl)-4-methylphenol; 2-n-dodecyl-6-(1,1,3,3-tetramethyloctyl)-4-methylphenol; 2-n-dodecyl-6-n-octadecyl-4-methylphenol; 2-n-dodecyl-6-n-octyl-4-methylphenol; 2-methyl-6-n-octadecyl-4-methylphenol; 2-n-dodecyl-6-(1-methylheptadecyl)-4-methylphenol; 2,6-di(1-methylbenzyl)-4-methylphenol; 2,6-di(1-methylcyclohexyl)-4-methylphenol; 2,6-(1-methylcyclohexyl)-4-methylphenol; 2-(1-methylbenzyl)-4-methylphenol; and related substituted phenols.
[0062] More suitable antioxidants include, but are not limited to, alkylene bisphenols, such as 4,4′-butylidene bis(3-methyl-6-t-butyl phenol); 2,2-butylidene bis(4,6-dimethyl phenol); 2,2′-butylidene bis(4-methyl-6-t-butyl phenol); 2,2′-butylidene bis(4-t-butyl-6-methyl phenol); 2,2′-ethylidene bis(4-methyl-6-t-butylphenol); 2,2′-methylene bis(4,6-dimethyl phenol); 2,2′-methylene bis(4-methyl-6-t-butyl phenol); 2,2′-methylene bis(4-ethyl-6-t-butyl phenol); 4,4′-methylene bis(2,6-di-t-butyl phenol); 4,4′-methylene bis(2-methyl-6-t-butyl phenol); 4,4′-methylene bis(2,6-dimethyl phenol); 2,2′-methylene bis(4-t-butyl-6-phenyl phenol); 2,2′-dihydroxy-3,3′,5,5′-tetramethylstilbene; 2,2′-isopropylidene bis(4-methyl-6-t-butyl phenol); ethylene bis(beta-naphthol); 1,5-dihydroxy naphthalene; 2,2′-ethylene bis(4-methyl-6-propyl phenol); 4,4′-methylene bis(2-propyl-6-t-butyl phenol); 4,4′-ethylene bis(2-methyl-6-propyl phenol); 2,2′-methylene bis(5-methyl-6-t-butyl phenol); and 4,4′-butylidene bis(6-t-butyl-3-methyl phenol);
[0063] Suitable antioxidants further include, but are not limited to, alkylene trisphenols, such as 2,6-bis(2′-hydroxy-3′-t-butyl-5′-methyl benzyl)-4-methyl phenol; 2,6-bis(2′-hydroxy-3′-t-ethyl-5′-butyl benzyl)-4-methyl phenol; and 2,6-bis(2′-hydroxy-3′-t-butyl-5′-propyl benzyl)-4-methyl phenol.
[0064] The antioxidant is typically present in an amount of about 0.1 phr to about 5 phr, preferably from about 0.1 phr to about 2 phr, more preferably about 0.1 phr to about 1 phr. In a particularly preferred embodiment, the antioxidant is present in an amount of about 0.4 phr. In an alternative embodiment, the antioxidant should be present in an amount to ensure that the hardness gradient of the inventive cores is negative. Preferably, about 0.2 phr to about 1 phr antioxidant is added to the core layer (inner core or outer core layer) formulation, more preferably, about 0.3 to about 0.8 phr, and most preferably 0.4 to about 0.7 phr. Preferably, about 0.25 phr to about 1.5 phr of peroxide as calculated at 100% active can be added to the core formulation, more preferably about 0.5 phr to about 1.2 phr, and most preferably about 0.7 phr to about 1.0 phr. The ZDA amount can be varied to suit the desired compression, spin and feel of the resulting golf ball. The cure regime can have a temperature range between from about 290° F. to about 360° F., or from about 290° F. to about 335° F., or from about 300° F. to about 325° F., or from about 330° F. to about 355° F., and the stock is held at that temperature for at least about 10 minutes to about 30 minutes.
[0065] The thermoset rubber composition in a core of the golf ball of the present invention may also include an optional soft and fast agent. As used herein, “soft and fast agent” means any compound or a blend thereof that that is capable of making a core 1) be softer (lower compression) at constant COR or 2) have a higher COR at equal compression, or any combination thereof, when compared to a core equivalently prepared without a soft and fast agent. Preferably, the composition of the present invention contains from about 0.05 phr to about 10.0 phr soft and fast agent. In one embodiment, the soft and fast agent is present in an amount of about 0.05 phr to about 3.0 phr, preferably about 0.05 phr to about 2.0 phr, more preferably about 0.05 phr to about 1.0 phr. In another embodiment, the soft and fast agent is present in an amount of about 2.0 phr to about 5.0 phr, preferably about 2.35 phr to about 4.0 phr, and more preferably about 2.35 phr to about 3.0 phr. In an alternative high concentration embodiment, the soft and fast agent is present in an amount of about 5.0 phr to about 10.0 phr, more preferably about 6.0 phr to about 9.0 phr, most preferably about 7.0 phr to about 8.0 phr. In a most preferred embodiment, the soft and fast agent is present in an amount of about 2.6 phr.
[0066] Suitable soft and fast agents include, but are not limited to, organosulfur or metal-containing organosulfur compounds, an organic sulfur compound, including mono, di, and polysulfides, a thiol, or mercapto compound, an inorganic sulfide compound, a Group VIA compound, or mixtures thereof. The soft and fast agent component may also be a blend of an organosulfur compound and an inorganic sulfide compound.
[0067] Suitable soft and fast agents of the present invention include, but are not limited to those having the following general formula:
[0000]
[0000] where R 1 -R 5 can be C 1 -C 8 alkyl groups; halogen groups; thiol groups (—SH), carboxylated groups; sulfonated groups; and hydrogen; in any order; and also pentafluorothiophenol; 2-fluorothiophenol; 3-fluorothiophenol; 4-fluorothiophenol; 2,3-fluorothiophenol; 2,4-fluorothiophenol; 3,4-fluorothiophenol; 3,5-fluorothiophenol 2,3,4-fluorothiophenol; 3,4,5-fluorothiophenol; 2,3,4,5-tetrafluorothiophenol; 2,3,5,6-tetrafluorothiophenol; 4-chlorotetrafluorothiophenol; pentachlorothiophenol; 2-chlorothiophenol; 3-chlorothiophenol; 4-chlorothiophenol; 2,3-chlorothiophenol; 2,4-chlorothiophenol; 3,4-chlorothiophenol; 3,5-chlorothiophenol; 2,3,4-chlorothiophenol; 3,4,5-chlorothiophenol; 2,3,4,5-tetrachlorothiophenol; 2,3,5,6-tetrachlorothiophenol; pentabromothiophenol; 2-bromothiophenol; 3-bromothiophenol; 4-bromothiophenol; 2,3-bromothiophenol; 2,4-bromothiophenol; 3,4-bromothiophenol; 3,5-bromothiophenol; 2,3,4-bromothiophenol; 3,4,5-bromothiophenol; 2,3,4,5-tetrabromothiophenol; 2,3,5,6-tetrabromothiophenol; pentaiodothiophenol; 2-iodothiophenol; 3-iodothiophenol; 4-iodothiophenol; 2,3-iodothiophenol; 2,4-iodothiophenol; 3,4-iodothiophenol; 3,5-iodothiophenol; 2,3,4-iodothiophenol; 3,4,5-iodothiophenol; 2,3,4,5-tetraiodothiophenol; 2,3,5,6-tetraiodothiophenol and; and their zinc salts. Preferably, the halogenated thiophenol compound is pentachlorothiophenol, which is commercially available in neat form or under the tradename STRUKTOL®, a clay-based carrier containing the sulfur compound pentachlorothiophenol loaded at 45 percent (correlating to 2.4 parts PCTP). STRUKTOL® is commercially available from Struktol Company of America of Stow, OH. PCTP is commercially available in neat form from eChinachem of San Francisco, Calif. and in the salt form from eChinachem of San Francisco, Calif. Most preferably, the halogenated thiophenol compound is the zinc salt of pentachlorothiophenol, which is commercially available from eChinachem of San Francisco, Calif.
[0068] As used herein when referring to the invention, the term “organosulfur compound(s)” refers to any compound containing carbon, hydrogen, and sulfur, where the sulfur is directly bonded to at least 1 carbon. As used herein, the term “sulfur compound” means a compound that is elemental sulfur, polymeric sulfur, or a combination thereof. It should be further understood that the term “elemental sulfur” refers to the ring structure of Ss and that “polymeric sulfur” is a structure including at least one additional sulfur relative to elemental sulfur.
[0069] Additional suitable examples of soft and fast agents (that are also believed to be cis-to-trans catalysts) include, but are not limited to, 4,4′-diphenyl disulfide; 4,4′-ditolyl disulfide; 2,2′-benzamido diphenyl disulfide; bis(2-aminophenyl)disulfide; bis(4-aminophenyl)disulfide; bis(3-aminophenyl)disulfide; 2,2′-bis(4-aminonaphthyl)disulfide; 2,2′-bis(3-aminonaphthyl)disulfide; 2,2′-bis(4-aminonaphthyl)disulfide; 2,2′-bis(5-aminonaphthyl)disulfide; 2,2′-bis(6-aminonaphthyl)disulfide; 2,2′-bis(7-aminonaphthyl)disulfide; 2,2′-bis(8-aminonaphthyl)disulfide; 1,1′-bis(2-aminonaphthyl)disulfide; 1,1′-bis(3-aminonaphthyl)disulfide; 1,1′-bis(3-aminonaphthyl)disulfide; 1,1′-bis(4-aminonaphthyl)disulfide; 1,1′-bis(5-aminonaphthyl)disulfide; 1,1′-bis(6-aminonaphthyl)disulfide; 1,1′-bis(7-aminonaphthyl)disulfide; 1,1′-bis(8-aminonaphthyl)disulfide; 1,2′-diamino-1,2′-dithiodinaphthalene; 2,3′-diamino-1,2′-dithiodinaphthalene; bis(4-chlorophenyl)disulfide; bis(2-chlorophenyl)disulfide; bis(3-chlorophenyl)disulfide; bis(4-bromophenyl)disulfide; bis(2-bromophenyl)disulfide; bis(3-bromophenyl)disulfide; bis(4-fluorophenyl)disulfide; bis(4-iodophenyl)disulfide; bis(2,5-dichlorophenyl)disulfide; bis(3,5-dichlorophenyl)disulfide; bis(2,4-dichlorophenyl)disulfide; bis(2,6-dichlorophenyl)disulfide; bis(2,5-dibromophenyl)disulfide; bis(3,5-dibromophenyl)disulfide; bis(2-chloro-5-bromophenyl)disulfide; bis(2,4,6-trichlorophenyl)disulfide; bis(2,3,4,5,6-pentachlorophenyl)disulfide; bis(4-cyanophenyl)disulfide; bis(2-cyanophenyl)disulfide; bis(4-nitrophenyl)disulfide; bis(2-nitrophenyl)disulfide; 2,2′-dithiobenzoic acid ethylester; 2,2′-dithiobenzoic acid methylester; 2,2′-dithiobenzoic acid; 4,4′-dithiobenzoic acid ethylester; bis(4-acetylphenyl)disulfide; bis(2-acetylphenyl)disulfide; bis(4-formylphenyl)disulfide; bis(4-carbamoylphenyl)disulfide; 1,1′-dinaphthyl disulfide; 2,2′-dinaphthyl disulfide; 1,2′-dinaphthyl disulfide; 2,2′-bis(1-chlorodinaphthyl)disulfide; 2,2′-bis(1-bromonaphthyl)disulfide; 1,1′-bis(2-chloronaphthyl)disulfide; 2,2′-bis(1-cyanonaphthyl)disulfide; 2,2′-bis(1-acetylnaphthyl)disulfide; and the like; or a mixture thereof. Preferred organosulfur components include 4,4′-diphenyl disulfide, 4,4′-ditolyl disulfide, or 2,2′-benzamido diphenyl disulfide, or a mixture thereof. A more preferred organosulfur component includes 4,4′-ditolyl disulfide. In another embodiment, metal-containing organosulfur components can be used according to the invention. Suitable metal-containing organosulfur components include, but are not limited to, cadmium, copper, lead, and tellurium analogs of diethyldithiocarbamate, diamyldithiocarbamate, and dimethyldithiocarbamate, or mixtures thereof.
[0070] Suitable substituted or unsubstituted aromatic organic components that do not include sulfur or a metal include, but are not limited to, 4,4′-diphenyl acetylene, azobenzene, or a mixture thereof. The aromatic organic group preferably ranges in size from C 6 to C 20 , and more preferably from C 6 to C 10 . Suitable inorganic sulfide components include, but are not limited to titanium sulfide, manganese sulfide, and sulfide analogs of iron, calcium, cobalt, molybdenum, tungsten, copper, selenium, yttrium, zinc, tin, and bismuth.
[0071] A substituted or unsubstituted aromatic organic compound is also suitable as a soft and fast agent. Suitable substituted or unsubstituted aromatic organic components include, but are not limited to, components having the formula (R 1 ) x —R 3 -M-R 4 —(R 2 ) y , wherein R 1 and R 2 are each hydrogen or a substituted or unsubstituted C 1-20 linear, branched, or cyclic alkyl, alkoxy, or alkylthio group, or a single, multiple, or fused ring C 6 to C 24 aromatic group; x and y are each an integer from 0 to 5; R 3 and R 4 are each selected from a single, multiple, or fused ring C 6 to C 24 aromatic group; and M includes an azo group or a metal component. R 3 and R 4 are each preferably selected from a C 6 to C 10 aromatic group, more preferably selected from phenyl, benzyl, naphthyl, benzamido, and benzothiazyl. R 1 and R 2 are each preferably selected from a substituted or unsubstituted C 1-10 linear, branched, or cyclic alkyl, alkoxy, or alkylthio group or a C 6 to C 10 aromatic group. When R 1 , R 2 , R 3 , or R 4 , are substituted, the substitution may include one or more of the following substituent groups: hydroxy and metal salts thereof; mercapto and metal salts thereof; halogen; amino, nitro, cyano, and amido; carboxyl including esters, acids, and metal salts thereof; silyl; acrylates and metal salts thereof; sulfonyl or sulfonamide; and phosphates and phosphites. When M is a metal component, it may be any suitable elemental metal available to those of ordinary skill in the art. Typically, the metal will be a transition metal, although preferably it is tellurium or selenium. In one embodiment, the aromatic organic compound is substantially free of metal, while in another embodiment the aromatic organic compound is completely free of metal.
[0072] The soft and fast agent can also include a Group VIA component. Elemental sulfur and polymeric sulfur are commercially available from Elastochem, Inc. of Chardon, Ohio Exemplary sulfur catalyst compounds include PB(RM-S)-80 elemental sulfur and PB(CRST)-65 polymeric sulfur, each of which is available from Elastochem, Inc. An exemplary tellurium catalyst under the tradename TELLOY® and an exemplary selenium catalyst under the tradename VANDEX® are each commercially available from RT Vanderbilt.
[0073] Fillers may also be added to the thermoset rubber composition of the core to adjust the density of the composition, up or down. Typically, fillers include materials such as tungsten, zinc oxide, barium sulfate, silica, calcium carbonate, zinc carbonate, metals, metal oxides and salts, regrind (recycled core material typically ground to about 30 mesh particle), high-Mooney-viscosity rubber regrind, trans-regrind core material (recycled core material containing high trans-isomer of polybutadiene), and the like. When trans-regrind is present, the amount of trans-isomer is preferably between about 10% and about 60%. In a preferred embodiment of the invention, the core comprises polybutadiene having a cis-isomer content of greater than about 95% and trans-regrind core material (already vulcanized) as a filler. Any particle size trans-regrind core material is sufficient, but is preferably less than about 125 μm.
[0074] Fillers added to one or more portions of the golf ball typically include processing aids or compounds to affect rheological and mixing properties, density-modifying fillers, tear strength, or reinforcement fillers, and the like. The fillers are generally inorganic, and suitable fillers include numerous metals or metal oxides, such as zinc oxide and tin oxide, as well as barium sulfate, zinc sulfate, calcium carbonate, barium carbonate, clay, tungsten, tungsten carbide, an array of silicas, and mixtures thereof. Fillers may also include various foaming agents or blowing agents which may be readily selected by one of ordinary skill in the art. Fillers may include polymeric, ceramic, metal, and glass microspheres may be solid or hollow, and filled or unfilled. Fillers are typically also added to one or more portions of the golf ball to modify the density thereof to conform to uniform golf ball standards. Fillers may also be used to modify the weight of the center or at least one additional layer for specialty balls, e.g., a lower weight ball is preferred for a player having a low swing speed.
[0075] Materials such as tungsten, zinc oxide, barium sulfate, silica, calcium carbonate, zinc carbonate, metals, metal oxides and salts, and regrind (recycled core material typically ground to about 30 mesh particle) are also suitable fillers.
[0076] The polybutadiene and/or any other base rubber or elastomer system may also be foamed, or filled with hollow microspheres or with expandable microspheres which expand at a set temperature during the curing process to any low specific gravity level. Other ingredients such as sulfur accelerators, e.g., tetramethylthiuram di, tri, or tetrasulfide, and/or metal-containing organosulfur components may also be used according to the invention. Suitable metal-containing organosulfur accelerators include, but are not limited to, cadmium, copper, lead, and tellurium analogs of diethyldithiocarbamate, diamyldithiocarbamate, and dimethyldithiocarbamate, or mixtures thereof. Other ingredients such as processing aids e.g., fatty acids and/or their metal salts, processing oils, dyes and pigments, as well as other additives known to one skilled in the art may also be used in the present invention in amounts sufficient to achieve the purpose for which they are typically used.
[0077] Without being bound by theory, it is believed that the percentage of double bonds in the trans configuration may be manipulated throughout a core containing at least one main-chain unsaturated rubber (i.e., polybutadiene), plastic, or elastomer resulting in a trans gradient. The trans gradient may be influenced (up or down) by changing the type and amount of cis-to-trans catalyst (or soft-and-fast agent), the type and amount of peroxide, and the type and amount of coagent in the formulation. For example, a formulation containing about 0.25 phr ZnPCTP may have a trans gradient of about 5% across the core whereas a formulation containing about 2 phr ZnPCTP may have a trans gradient of about 10%, or higher. The trans gradient may also be manipulated through the cure times and temperatures. It is believed that lower temperatures and shorter cure times yield lower trans gradients, although a combination of many of these factors may yield gradients of differing and/or opposite directions from that resulting from use of a single factor.
[0078] In general, higher and/or faster cure rates tend to yield higher levels of trans content, as do higher concentrations of peroxides, soft-and-fast agents, and, to some extent, ZDA concentration. Even the type of rubber may have an effect on trans levels, with those catalyzed by rare-earth metals, such as Nd, being able to form higher levels of trans polybutadiene compared to those rubbers formed from Group VIII metals, such as Co, Ni, and Li.
[0079] Cores may have an outer surface and a center and be formed from a substantially homogenous rubber composition. An intermediate layer, such as a casing layer (inner cover), is disposed about the core, and a cover layer is formed around the intermediate layer, the cover being formed from the materials detailed herein. In some embodiments, a hardness of the outer surface of the core differs from a hardness of the geometric center as defined herein. In other embodiments, the hardness of the outer surface and hardness of the geometric center do not differ.
[0080] Additionally, a core may have a ‘dual core’ arrangement, including a center and at least one outer core layer.
[0081] The center hardness of a core is obtained according to the following procedure. The core is gently pressed into a hemispherical holder having an internal diameter approximately slightly smaller than the diameter of the core, such that the core is held in place in the hemispherical portion of the holder while concurrently leaving the geometric central plane of the core exposed. The core is secured in the holder by friction, such that it will not move during the cutting and grinding steps, but the friction is not so excessive that distortion of the natural shape of the core would result. The core is secured such that the parting line of the core is roughly parallel to the top of the holder. The diameter of the core is measured 90 degrees to this orientation prior to securing. A measurement is also made from the bottom of the holder to the top of the core to provide a reference point for future calculations. A rough cut is made slightly above the exposed geometric center of the core using a band saw or other appropriate cutting tool, making sure that the core does not move in the holder during this step. The remainder of the core, still in the holder, is secured to the base plate of a surface grinding machine. The exposed ‘rough’ surface is ground to a smooth, flat surface, revealing the geometric center of the core, which can be verified by measuring the height from the bottom of the holder to the exposed surface of the core, making sure that exactly half of the original height of the core, as measured above, has been removed to within ±0.004 inches. Leaving the core in the holder, the center of the core is found with a center square and carefully marked and the hardness is measured at the center mark according to ASTM D-2240. Additional hardness measurements at any distance from the center of the core can then be made by drawing a line radially outward from the center mark, and measuring the hardness at any given distance along the line, typically in 2 mm increments from the center. The hardness at a particular distance from the center should be measured along at least two, preferably four, radial arms located 180° apart, or 90° apart, respectively, and then averaged. All hardness measurements performed on a plane passing through the geometric center are performed while the core is still in the holder and without having disturbed its orientation, such that the test surface is constantly parallel to the bottom of the holder, and thus also parallel to the properly aligned foot of the durometer.
[0082] The hardness of a core may be measured by taking measurements at the center of the core and radially outward toward the surface of the core, typically at 2-mm increments. As used herein, the terms “negative” and “positive” refer to the result of subtracting the hardness value at the innermost portion of the component being measured (e.g., the center of a core) from the hardness value at the outer surface of the component being measured (e.g., the outer surface of the single core or the outer surface of an outer core layer in a dual core arrangement, etc.).
[0083] The center hardness of a core and the outer surfaces of a single core or outer core layer in a multi-layer core arrangement are readily determined according to the procedures given herein if the measurement is made prior to surrounding the layer with an additional core layer.
[0084] Once an additional core layer surrounds a layer of interest, the hardness of the inner and outer surfaces of any inner or intermediate layers can be difficult to determine so that a different procedure detailed below may be used for measuring a point located 1 mm from an interface is used. The hardness of a golf ball layer at a point located 1 mm from an interface is obtained according to the following procedure. First, an axis defining the geometric center of the core is revealed by preparing the core according to the above procedure for measuring the center hardness of a core. Leaving the core in the holder, a point located 1 mm radially inward or outward from the interface of two layers is determined and marked, and the hardness thereof is measured according to ASTM D-2240.
[0085] The outer surface hardness of a golf ball layer is measured on the actual outer surface of the layer and is obtained from the average of a number of measurements taken from opposing hemispheres, taking care to avoid making measurements on the parting line of the core or on surface defects, such as holes or protrusions. Hardness measurements are made pursuant to ASTM D-2240 “Indentation Hardness of Rubber and Plastic by Means of a Durometer.” Because of the curved surface, care must be taken to insure that the golf ball or golf ball subassembly is centered under the durometer indentor before a surface hardness reading is obtained. A calibrated, digital durometer, capable of reading to 0.1 hardness units is used for all hardness measurements and the maximum reading is obtained. The digital durometer must be attached to, and its foot made parallel to, the base of an automatic stand. The weight on the durometer and attack rate conform to ASTM D-2240.
[0086] The ratio of antioxidant to initiator is one factor to control the surface hardness of the cores.
[0087] In all preferred embodiments of invention, the hardness of the core at the surface is at most about the same as or different than the hardness of the core at the center as defined herein. Furthermore, the center hardness of the core may not be the hardest point in the core, but in all cases, it is preferred that it is at least equal to or harder than the surface. Additionally, the lowest hardness anywhere in the core does not have to occur at the surface. In some embodiments, the lowest hardness value occurs within about the outer 6 mm of the core surface. However, the lowest hardness value within the core can occur at any point from the surface, up to, but not including the center, as long as the surface hardness is still equal to, or less than the hardness of the center. It should be noted that in the present invention the formulation is the same throughout the core, or core layer, and no surface treatment is applied to the core to obtain the preferred surface hardness.
[0088] The casing layer may be made from a variety of materials. In one embodiment, the casing layer is formed from an ionomeric material including ionomeric polymers, preferably highly-neutralized ionomers (HNP). In another embodiment, the casing layer of the golf ball is formed from an HNP material or a blend of HNP materials. The acid moieties of the HNP's, typically ethylene-based ionomers, are preferably neutralized greater than about 70%, more preferably greater than about 90%, and most preferably at least about 100%. The HNP's can be also be blended with a second polymer component, which, if containing an acid group, may also be neutralized. The second polymer component, which may be partially or fully neutralized, preferably comprises ionomeric copolymers and terpolymers, ionomer precursors, thermoplastics, polyamides, polycarbonates, polyesters, polyurethanes, polyureas, thermoplastic elastomers, polybutadiene rubber, balata, metallocene-catalyzed polymers (grafted and non-grafted), single-site polymers, high-crystalline acid polymers, cationic ionomers, and the like. HNP polymers typically have a material hardness of between about 20 and about 80 Shore D, and a flexural modulus of between about 3,000 psi and about 200,000 psi.
[0089] In one embodiment of the present invention the HNP's are ionomers and/or their acid precursors that are preferably neutralized, either fully or partially, with a suitable base. The acid copolymers are preferably α-olefin, such as ethylene, C 3-8 α,β-ethylenically unsaturated carboxylic acid, such as acrylic and methacrylic acid, copolymers. They may optionally contain a softening monomer, such as alkyl acrylate and alkyl methacrylate, wherein the alkyl groups have from 1 to 8 carbon atoms.
[0090] The acid copolymers can be described as E/X/Y copolymers where E is ethylene, X is an α,β-ethylenically unsaturated carboxylic acid, and Y is a softening comonomer. In a preferred embodiment, X is acrylic or methacrylic acid and Y is a C 1-8 alkyl acrylate or methacrylate ester. X is preferably present in an amount from about 1 to about 35 weight percent of the polymer, more preferably from about 5 to about 30 weight percent of the polymer, and most preferably from about 10 to about 20 weight percent of the polymer. Y is preferably present in an amount from about 0 to about 50 weight percent of the polymer, more preferably from about 5 to about 25 weight percent of the polymer, and most preferably from about 10 to about 20 weight percent of the polymer.
[0091] Specific acid-containing ethylene copolymers include, but are not limited to, ethylene/acrylic acid/n-butyl acrylate, ethylene/methacrylic acid/n-butyl acrylate, ethylene/methacrylic acid/iso-butyl acrylate, ethylene/acrylic acid/iso-butyl acrylate, ethylene/methacrylic acid/n-butyl methacrylate, ethylene/acrylic acid/methyl methacrylate, ethylene/acrylic acid/methyl acrylate, ethylene/methacrylic acid/methyl acrylate, ethylene/methacrylic acid/methyl methacrylate, and ethylene/acrylic acid/n-butyl methacrylate. Preferred acid-containing ethylene copolymers include, ethylene/methacrylic acid/n-butyl acrylate, ethylene/acrylic acid/n-butyl acrylate, ethylene/methacrylic acid/methyl acrylate, ethylene/acrylic acid/ethyl acrylate, ethylene/methacrylic acid/ethyl acrylate, and ethylene/acrylic acid/methyl acrylate copolymers. The most preferred acid-containing ethylene copolymers are, ethylene/(meth) acrylic acid/n-butyl, acrylate, ethylene/(meth)acrylic acid/ethyl acrylate, and ethylene/(meth) acrylic acid/methyl acrylate copolymers.
[0092] Ionomers are typically neutralized with a metal cation, such as Li, Na, Mg, K, Ca, or Zn. It has been found that by adding sufficient organic acid or salt of organic acid, along with a suitable base, to the acid copolymer or ionomer, however, the ionomer can be neutralized, without losing processability, to a level much greater than for a metal cation. Preferably, the acid moieties are neutralized greater than about 80%, preferably from 90-100%, most preferably 100% without losing processability. This accomplished by melt-blending an ethylene α,β-ethylenically unsaturated carboxylic acid copolymer, for example, with an organic acid or a salt of organic acid, and adding a sufficient amount of a cation source to increase the level of neutralization of all the acid moieties (including those in the acid copolymer and in the organic acid) to greater than 90%, (preferably greater than 100%).
[0093] The organic acids of the present invention are aliphatic, mono- or multi-functional (saturated, unsaturated, or multi-unsaturated) organic acids. Salts of these organic acids may also be employed. The salts of organic acids of the present invention include the salts of barium, lithium, sodium, zinc, bismuth, chromium, cobalt, copper, potassium, strontium, titanium, tungsten, magnesium, cesium, iron, nickel, silver, aluminum, tin, or calcium, salts of fatty acids, particularly stearic, behenic, erucic, oleic, linoelic or dimerized derivatives thereof. It is preferred that the organic acids and salts of the present invention be relatively non-migratory (they do not bloom to the surface of the polymer under ambient temperatures) and non-volatile (they do not volatilize at temperatures required for melt-blending).
[0094] The ionomers of the invention may also be more conventional ionomers, i.e., partially-neutralized with metal cations. The acid moiety in the acid copolymer is neutralized about 1 to about 90%, preferably at least about 20 to about 75%, and more preferably at least about 40 to about 70%, to form an ionomer, by a cation such as lithium, sodium, potassium, magnesium, calcium, barium, lead, tin, zinc, aluminum, or a mixture thereof.
[0095] Any golf ball component, namely core, casing layer, cover, etc. may also be formed from or comprise or include or be blended or otherwise combined or mixed with any of the following compositions as known in the art. Additionally, such materials may also or alternatively be mixed, blended or otherwise combined with the inventive cover composition to achieve particular desired golf ball characteristics:
(1) Polyurethanes, such as those prepared from polyols and diisocyanates or polyisocyanates and/or their prepolymers, and those disclosed in U.S. Pat. Nos. 5,334,673 and 6,506,851; (2) Polyureas, such as those disclosed in U.S. Pat. Nos. 5,484,870 and 6,835,794; and (3) Polyurethane-urea hybrids, blends or copolymers comprising urethane or urea segments.
[0099] Suitable polyurethane compositions comprise a reaction product of at least one polyisocyanate and at least one curing agent. The curing agent can include, for example, one or more polyols. The polyisocyanate can be combined with one or more polyols to form a prepolymer, which is then combined with the at least one curing agent. Thus, the polyols described herein are suitable for use in one or both components of the polyurethane material, i.e., as part of a prepolymer and in the curing agent. Suitable polyurethanes are described in U.S. Pat. No. 7,331,878, which is incorporated herein in its entirety by reference.
[0100] Any polyol available to one of ordinary skill in the art is suitable for use according to the invention. Exemplary polyols include, but are not limited to, polyether polyols, hydroxy-terminated polybutadiene (including partially/fully hydrogenated derivatives), polyester polyols, polycaprolactone polyols, and polycarbonate polyols. In one preferred embodiment, the polyol includes polyether polyol. Examples include, but are not limited to, polytetramethylene ether glycol (PTMEG), polyethylene propylene glycol, polyoxypropylene glycol, and mixtures thereof. The hydrocarbon chain can have saturated or unsaturated bonds and substituted or unsubstituted aromatic and cyclic groups. Preferably, the polyol of the present invention includes PTMEG.
[0101] In another embodiment, polyester polyols are included in the polyurethane material. Suitable polyester polyols include, but are not limited to, polyethylene adipate glycol; polybutylene adipate glycol; polyethylene propylene adipate glycol; o-phthalate-1,6-hexanediol; poly(hexamethylene adipate)glycol; and mixtures thereof. The hydrocarbon chain can have saturated or unsaturated bonds, or substituted or unsubstituted aromatic and cyclic groups. In another embodiment, polycaprolactone polyols are included in the materials of the invention. Suitable polycaprolactone polyols include, but are not limited to, 1,6-hexanediol-initiated polycaprolactone, diethylene glycol initiated polycaprolactone, trimethylol propane initiated polycaprolactone, neopentyl glycol initiated polycaprolactone, 1,4-butanediol-initiated polycaprolactone, and mixtures thereof. The hydrocarbon chain can have saturated or unsaturated bonds, or substituted or unsubstituted aromatic and cyclic groups.
[0102] In yet another embodiment, polycarbonate polyols are included in the polyurethane material of the invention. Suitable polycarbonates include, but are not limited to, polyphthalate carbonate and poly(hexamethylene carbonate)glycol. The hydrocarbon chain can have saturated or unsaturated bonds, or substituted or unsubstituted aromatic and cyclic groups. In one embodiment, the molecular weight of the polyol is from about 200 to about 4000. Polyamine curatives are also suitable for use in the polyurethane composition of the invention and have been found to improve cut, shear, and impact resistance of the resultant balls. Preferred polyamine curatives include, but are not limited to, 3,5-dimethylthio-2,4-toluenediamine and isomers thereof; 3,5-diethyltoluene-2,4-diamine and isomers thereof, such as 3,5-diethyltoluene-2,6-diamine; 4,4′-bis-(sec-butylamino)-diphenylmethane; 1,4-bis-(sec-butylamino)-benzene, 4,4′-methylene-bis-(2-chloroaniline); 4,4′-methylene-bis-(3-chloro-2,6-diethylaniline); polytetramethyleneoxide-di-p-aminobenzoate; N,N′-dialkyldiamino diphenyl methane; p,p′-methylene dianiline; m-phenylenediamine; 4,4′-methylene-bis-(2-chloroaniline); 4,4′-methylene-bis-(2,6-diethylaniline); 4,4′-methylene-bis-(2,3-dichloroaniline); 4,4′-diamino-3,3′-diethyl-5,5′-dimethyl diphenylmethane; 2,2′,3,3′-tetrachloro diamino diphenylmethane; trimethylene glycol di-p-aminobenzoate; and mixtures thereof. Preferably, the curing agent of the present invention includes 3,5-dimethylthio-2,4-toluenediamine and isomers thereof, such as ETHACURE® 300, commercially available from Albermarle Corporation of Baton Rouge, La. Suitable polyamine curatives, which include both primary and secondary amines, preferably have molecular weights ranging from about 64 to about 2000.
[0103] At least one of a diol, triol, tetraol, or hydroxy-terminated curatives may be added to the aforementioned polyurethane composition. Suitable diol, triol, and tetraol groups include ethylene glycol; diethylene glycol; polyethylene glycol; propylene glycol; polypropylene glycol; lower molecular weight polytetramethylene ether glycol; 1,3-bis(2-hydroxyethoxy)benzene; 1,3-bis-[2-(2-hydroxyethoxyl)ethoxy]benzene; 1,3-bis-{2-[2-(2-hydroxyethoxyl)ethoxy]ethoxy}benzene; 1,4-butanediol; 1,5-pentanediol; 1,6-hexanediol; resorcinol-di-(β-hydroxyethyl) ether; hydroquinone-di-(β-hydroxyethyl) ether; and mixtures thereof. Preferred hydroxy-terminated curatives include 1,3-bis(2-hydroxyethoxy)benzene; 1,3-bis-[2-(2-hydroxyethoxyl)ethoxy]benzene; 1,3-bis-{2-[2-(2-hydroxyethoxyl)ethoxy]ethoxy}benzene; 1,4-butanediol, and mixtures thereof. Preferably, the hydroxy-terminated curatives have molecular weights ranging from about 48 to 2000. It should be understood that molecular weight, as used herein, is the absolute weight average molecular weight and would be understood as such by one of ordinary skill in the art.
[0104] Both the hydroxy-terminated and amine curatives can include one or more saturated, unsaturated, aromatic, and cyclic groups. Additionally, the hydroxy-terminated and amine curatives can include one or more halogen groups. The polyurethane composition can be formed with a blend or mixture of curing agents. If desired, however, the polyurethane-urea composition may be formed with a single curing agent.
[0105] In a preferred embodiment of the present invention, saturated polyurethanes are used to form one or more of the cover layers, preferably the outer cover layer, and may be selected from among both castable thermoset and thermoplastic polyurethanes.
[0106] In this embodiment, the saturated polyurethanes of the present invention are substantially free of aromatic groups or moieties. Saturated polyurethanes suitable for use in the invention are a product of a reaction between at least one polyurethane prepolymer and at least one saturated curing agent. The polyurethane prepolymer is a product formed by a reaction between at least one saturated polyol and at least one saturated diisocyanate. As is well known in the art, that a catalyst may be employed to promote the reaction between the curing agent and the isocyanate and polyol, or the curing agent and the prepolymer.
[0107] Saturated diisocyanates which can be used include, without limitation, ethylene diisocyanate; propylene-1,2-diisocyanate; tetramethylene-1,4-diisocyanate; 1,6-hexamethylene-diisocyanate (HDI); 2,2,4-trimethylhexamethylene diisocyanate; 2,4,4-trimethylhexamethylene diisocyanate; dodecane-1,12-diisocyanate; dicyclohexylmethane diisocyanate; cyclobutane-1,3-diisocyanate; cyclohexane-1,3-diisocyanate; cyclohexane-1,4-diisocyanate; 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane; isophorone diisocyanate; methyl cyclohexylene diisocyanate; triisocyanate of HDI; triisocyanate of 2,2,4-trimethyl-1,6-hexane diisocyanate.
[0108] Saturated polyols which are appropriate for use in this invention include without limitation polyether polyols such as polytetramethylene ether glycol and poly(oxypropylene)glycol. Suitable saturated polyester polyols include polyethylene adipate glycol, polyethylene propylene adipate glycol, polybutylene adipate glycol, polycarbonate polyol and ethylene oxide-capped polyoxypropylene diols. Saturated polycaprolactone polyols which are useful in the invention include diethylene glycol-initiated polycaprolactone, 1,4-butanediol-initiated polycaprolactone, 1,6-hexanediol-initiated polycaprolactone; trimethylol propane-initiated polycaprolactone, neopentyl glycol initiated polycaprolactone, and polytetramethylene ether glycol-initiated polycaprolactone. The most preferred saturated polyols are polytetramethylene ether glycol and PTMEG-initiated polycaprolactone.
[0109] Suitable saturated curatives include 1,4-butanediol, ethylene glycol, diethylene glycol, polytetramethylene ether glycol, propylene glycol; trimethanolpropane; tetra-(2-hydroxypropyl)-ethylenediamine; isomers and mixtures of isomers of cyclohexyldimethylol, isomers and mixtures of isomers of cyclohexane bis(methylamine); triisopropanolamine; ethylene diamine; diethylene triamine; triethylene tetramine; tetraethylene pentamine; 4,4′-dicyclohexylmethane diamine; 2,2,4-trimethyl-1,6-hexanediamine; 2,4,4-trimethyl-1,6-hexanediamine; diethyleneglycol di-(aminopropyl)ether; 4,4′-bis-(sec-butylamino)-dicyclohexylmethane; 1,2-bis-(sec-butylamino)cyclohexane; 1,4-bis-(sec-butylamino)cyclohexane; isophorone diamine; hexamethylene diamine; propylene diamine; 1-methyl-2,4-cyclohexyl diamine; 1-methyl-2,6-cyclohexyl diamine; 1,3-diaminopropane; dimethylamino propylamine; diethylamino propylamine; imido-bis-propylamine; isomers and mixtures of isomers of diaminocyclohexane; monoethanolamine; diethanolamine; triethanolamine; monoisopropanolamine; and diisopropanolamine. The most preferred saturated curatives are 1,4-butanediol, 1,4-cyclohexyldimethylol and 4,4′-bis-(sec-butylamino)-dicyclohexylmethane.
[0110] Alternatively, other suitable polymers include partially or fully neutralized ionomer, metallocene, or other single-site catalyzed polymer, polyester, polyamide, non-ionomeric thermoplastic elastomer, copolyether-esters, copolyether-amides, polycarbonate, polybutadiene, polyisoprene, polystryrene block copolymers (such as styrene-butadiene-styrene), styrene-ethylene-propylene-styrene, styrene-ethylene-butylene-styrene, and the like, and blends thereof. Thermosetting polyurethanes or polyureas are suitable for the outer cover layers of the golf balls of the present invention.
[0111] Additionally, the polyurethane can be replaced with or blended with a polyurea material. Polyureas are distinctly different from polyurethane compositions, but also result in desirable aerodynamic and aesthetic characteristics when used in golf ball components. The polyurea-based compositions are preferably saturated in nature.
[0112] Without being bound to any particular theory, it is now believed that substitution of the long chain polyol segment in the polyurethane prepolymer with a long chain polyamine oligomer soft segment to form a polyurea prepolymer, improves shear, cut, and resiliency, as well as adhesion to other components. Thus, the polyurea compositions of this invention may be formed from the reaction product of an isocyanate and polyamine prepolymer crosslinked with a curing agent. For example, polyurea-based compositions of the invention may be prepared from at least one isocyanate, at least one polyether amine.
[0113] Any polyamine available to one of ordinary skill in the art is suitable for use in the polyurea prepolymer. Polyether amines are particularly suitable for use in the prepolymer. As used herein, “polyether amines” refer to at least polyoxyalkyleneamines containing primary amino groups attached to the terminus of a polyether backbone. Due to the rapid reaction of isocyanate and amine, and the insolubility of many urea products, however, the selection of diamines and polyether amines is limited to those allowing the successful formation of the polyurea prepolymers. In one embodiment, the polyether backbone is based on tetramethylene, propylene, ethylene, trimethylolpropane, glycerin, and mixtures thereof.
[0114] Suitable polyether amines include, but are not limited to, methyldiethanolamine; polyoxyalkylenediamines such as, polytetramethylene ether diamines, polyoxypropylenetriamine, and polyoxypropylene diamines; poly(ethylene oxide capped oxypropylene) ether diamines; propylene oxide-based triamines; triethyleneglycoldiamines; trimethylolpropane-based triamines; glycerin-based triamines; and mixtures thereof. In one embodiment, the polyether amine used to form the prepolymer is JEFFAMINE® D2000 (manufactured by Huntsman Chemical Co. of Austin, Tex.).
[0115] The molecular weight of the polyether amine for use in the polyurea prepolymer may range from about 100 to about 5000. In one embodiment, the polyether amine molecular weight is about 200 or greater, preferably about 230 or greater. In another embodiment, the molecular weight of the polyether amine is about 4000 or less. In yet another embodiment, the molecular weight of the polyether amine is about 600 or greater. In still another embodiment, the molecular weight of the polyether amine is about 3000 or less. In yet another embodiment, the molecular weight of the polyether amine is between about 1000 and about 3000, and more preferably is between about 1500 to about 2500. Because lower molecular weight polyether amines may be prone to forming solid polyureas, a higher molecular weight oligomer, such as JEFFAMINE® D2000, is preferred.
[0116] As briefly discussed above, some amines may be unsuitable for reaction with the isocyanate because of the rapid reaction between the two components. In particular, shorter chain amines are fast reacting. In one embodiment, however, a hindered secondary diamine may be suitable for use in the prepolymer. Without being bound to any particular theory, it is believed that an amine with a high level of stearic hindrance, e.g., a tertiary butyl group on the nitrogen atom, has a slower reaction rate than an amine with no hindrance or a low level of hindrance. For example, 4,4′-bis-(sec-butylamino)-dicyclohexylmethane (CLEARLINK® 1000) may be suitable for use in combination with an isocyanate to form the polyurea prepolymer.
[0117] The number of unreacted NCO groups in the polyurea prepolymer may be varied to control such factors as the speed of the reaction, the resultant hardness of the composition, and the like. For instance, the number of unreacted NCO groups in the polyurea prepolymer and polyether amine may be less than about 14 percent. In one embodiment, the polyurea prepolymer has from about 5 percent to about 11 percent unreacted NCO groups, and even more preferably has from about 6 to about 9.5 percent unreacted NCO groups. In one embodiment, the percentage of unreacted NCO groups is about 3 percent to about 9 percent. Alternatively, the percentage of unreacted NCO groups in the polyurea prepolymer may be about 7.5 percent or less, and more preferably, about 7 percent or less. In another embodiment, the unreacted NCO content is from about 2.5 percent to about 7.5 percent, and more preferably from about 4 percent to about 6.5 percent.
[0118] When formed, polyurea prepolymers may contain about 10 percent to about 20 percent by weight of the prepolymer of free isocyanate monomer. Thus, in one embodiment, the polyurea prepolymer may be stripped of the free isocyanate monomer. For example, after stripping, the prepolymer may contain about 1 percent or less free isocyanate monomer. In another embodiment, the prepolymer contains about 0.5 percent by weight or less of free isocyanate monomer.
[0119] The polyether amine may be blended with additional polyols to formulate copolymers that are reacted with excess isocyanate to form the polyurethane/polyurea hybrid. In one embodiment, less than about 30 percent polyol by weight of the copolymer is blended with the saturated polyether amine. In another embodiment, less than about 20 percent polyol by weight of the copolymer, preferably less than about 15 percent by weight of the copolymer, is blended with the polyether amine. The polyols listed above with respect to the polyurethane prepolymer, e.g., polyether polyols, polycaprolactone polyols, polyester polyols, polycarbonate polyols, hydrocarbon polyols, other polyols, and mixtures thereof, are also suitable for blending with the polyether amine. The molecular weight of these polymers may be from about 200 to about 4000, but also may be from about 1000 to about 3000, and more preferably are from about 1500 to about 2500.
[0120] The polyurea composition can be formed by crosslinking the polyurea prepolymer with a single curing agent or a blend of curing agents. The curing agent of the invention is preferably an amine-terminated curing agent, more preferably a secondary diamine curing agent so that the composition contains only urea linkages. In one embodiment, the amine-terminated curing agent may have a molecular weight of about 64 or greater. In another embodiment, the molecular weight of the amine-curing agent is about 2000 or less. As discussed above, certain amine-terminated curing agents may be modified with a compatible amine-terminated freezing point depressing agent or mixture of compatible freezing point depressing agents.
[0121] Suitable amine-terminated curing agents include, but are not limited to, ethylene diamine; hexamethylene diamine; 1-methyl-2,6-cyclohexyl diamine; tetrahydroxypropylene ethylene diamine; 2,2,4- and 2,4,4-trimethyl-1,6-hexanediamine; 4,4′-bis-(sec-butylamino)-dicyclohexylmethane; 1,4-bis-(sec-butylamino)-cyclohexane; 1,2-bis-(sec-butylamino)-cyclohexane; derivatives of 4,4′-bis-(sec-butylamino)-dicyclohexylmethane; 4,4′-dicyclohexylmethane diamine; 1,4-cyclohexane-bis-(methylamine); 1,3-cyclohexane-bis-(methylamine); diethylene glycol di-(aminopropyl) ether; 2-methylpentamethylene-diamine; diaminocyclohexane; diethylene triamine; triethylene tetramine; tetraethylene pentamine; propylene diamine; 1,3-diaminopropane; dimethylamino propylamine; diethylamino propylamine; dipropylene triamine; imido-bis-propylamine; monoethanolamine, diethanolamine; triethanolamine; monoisopropanolamine, diisopropanolamine; isophoronediamine; 4,4′-methylenebis-(2-chloroaniline); 3,5; dimethylthio-2,4-toluenediamine; 3,5-dimethylthio-2,6-toluenediamine; 3,5-diethylthio-2,4-toluenediamine; 3,5; diethylthio-2,6-toluenediamine; 4,4′-bis-(sec-butylamino)-diphenylmethane and derivatives thereof; 1,4-bis-(sec-butylamino)-benzene; 1,2-bis-(sec-butylamino)-benzene; N,N′-dialkylamino-diphenylmethane; N,N,N′,N′-tetrakis(2-hydroxypropyl)ethylene diamine; trimethyleneglycol-di-p-aminobenzoate; polytetramethyleneoxide-di-p-aminobenzoate; 4,4′-methylenebis-(3-chloro-2,6-diethyleneaniline); 4,4′-methylenebis-(2,6-diethylaniline); meta-phenylenediamine; paraphenylenediamine; and mixtures thereof. In one embodiment, the amine-terminated curing agent is 4,4′-bis-(sec-butylamino)-dicyclohexylmethane.
[0122] Suitable saturated amine-terminated curing agents include, but are not limited to, ethylene diamine; hexamethylene diamine; 1-methyl-2,6-cyclohexyl diamine; tetrahydroxypropylene ethylene diamine; 2,2,4- and 2,4,4-trimethyl-1,6-hexanediamine; 4,4′-bis-(sec-butylamino)-dicyclohexylmethane; 1,4-bis-(sec-butylamino)-cyclohexane; 1,2-bis-(sec-butylamino)-cyclohexane; derivatives of 4,4′-bis-(sec-butylamino)-dicyclohexylmethane; 4,4′-dicyclohexylmethane diamine; 4,4′-methylenebis-(2,6-diethylaminocyclohexane; 1,4-cyclohexane-bis-(methylamine); 1,3-cyclohexane-bis-(methylamine); diethylene glycol di-(aminopropyl) ether; 2-methylpentamethylene-diamine; diaminocyclohexane; diethylene triamine; triethylene tetramine; tetraethylene pentamine; propylene diamine; 1,3-diaminopropane; dimethylamino propylamine; diethylamino propylamine; imido-bis-propylamine; monoethanolamine, diethanolamine; triethanolamine; monoisopropanolamine, diisopropanolamine; isophoronediamine; triisopropanolamine; and mixtures thereof. In addition, any of the polyether amines listed above may be used as curing agents to react with the polyurea prepolymers.
[0123] In a golf ball of the invention, the cover preferably comprises an opaque or translucent thermoset or thermoplastic aliphatic isocyanate-based material.
[0124] The flexural modulus of the cover material of a golf ball of the invention may be evaluated according to ASTM D-790.
[0125] Compression values are dependent on the diameter of the component being measured. In the present invention, a solid 1.55′ sphere of inventive material may have a DCM compression anywhere from −75 to about 200, depending on the desired properties of the resulting golf ball, although numerous preferred ranges are as disclosed and coordinated herein. The Dynamic Compression Machine (“DCM”) is an apparatus that applies a load to a core or ball and measures the number of inches the core or ball is deflected at measured loads. A crude load/deflection curve is generated that is fit to the Atti compression scale that results in a number being generated representing an Atti compression. The DCM does this via a load cell attached to the bottom of a hydraulic cylinder that is triggered pneumatically at a fixed rate (typically about 1.0 ft/s) towards a stationary core. Attached to the cylinder is an LVDT that measures the distance the cylinder travels during the testing timeframe. A software-based logarithmic algorithm ensures that measurements are not taken until at least five successive increases in load are detected during the initial phase of the test. DCM is often used to capture compressions that fall outside the Atti compression scale range of −75 to 200, since the DCM scale compression range is −246 to 200.
[0126] COR, as used herein, is determined by firing a golf ball or golf ball subassembly (e.g., a golf ball core) from an air cannon at two given velocities and calculating the COR at a velocity of 125 ft/s. Ball velocity is calculated as a ball approaches ballistic light screens which are located between the air cannon and a steel plate at a fixed distance. As the ball travels toward the steel plate, each light screen is activated, and the time at each light screen is measured. This provides an incoming transit time period inversely proportional to the ball's incoming velocity. The ball impacts the steel plate and rebounds though the light screens, which again measure the time period required to transit between the light screens. This provides an outgoing transit time period inversely proportional to the ball's outgoing velocity. COR is then calculated as the ratio of the outgoing transit time period to the incoming transit time period, COR=V out /V in =T in /T out . The COR value can be targeted by varying the peroxide and antioxidant types and amounts as well as the cure temperature and duration. The COR value can be targeted by varying the peroxide and antioxidant types and amounts as well as the cure temperature and duration.
[0127] The cover of the golf ball of the present invention may comprise any known color and optionally comprise surface off-sets, or depressions or projections, on its surface. Surface off-sets include dimples and marking other than dimples. For instance, the surface of the translucent cover may comprise depressed logos, text, lines, arcs, circles or polygons. The surface may also comprise raised projections in the form of logos, text, lines, arcs, circles or polygons. The inclusion of such surface off-sets on the translucent cover creates a unique visual effect, as the juxtaposition of thick and thin portions of the translucent cover material creates a “shadow” effect on the opaque surface below the translucent cover.
[0128] While any of the embodiments herein may have any known dimple number and pattern, a preferred number of dimples is 252 to 456, and more preferably is 330 to 392. The dimples may comprise any width, depth, and edge angle disclosed in the prior art and the patterns may comprises multitudes of dimples having different widths, depths and edge angles. The parting line configuration of said pattern may be either a straight line or a staggered wave parting line (SWPL). Most preferably the dimple number is 330, 332, or 392 and comprises 5 to 7 dimples sizes and the parting line is a SWPL.
[0129] In any of these embodiments the single-layer core may be replaced with a 2 or more layer core wherein at least one core layer has a hardness gradient.
[0130] Other than in the operating examples, or unless otherwise expressly specified, all of the numerical ranges, amounts, values and percentages such as those for amounts of materials and others in the specification may be read as if prefaced by the word “about” even though the term “about” may not expressly appear with the value, amount or range. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
[0131] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Furthermore, when numerical ranges of varying scope are set forth herein, it is contemplated that any combination of these values inclusive of the recited values may be used.
[0132] While it is apparent that the illustrative embodiments of the invention disclosed herein fulfill the objective stated above, it is appreciated that numerous modifications and other embodiments may be devised by those skilled in the art. Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments, which would come within the spirit and scope of the present invention.
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A golf ball comprising: a core; a casing layer surrounding the core; and a cover layer surrounding the casing layer and being formed from a cover composition that is produced by a reaction of a prepolymer and a chain extender, wherein the prepolymer is formed from the reaction product of: (i) an isocyanate comprising an allophanate (“ICA”) and having an average NCO functionality in the range of 1.9 to 2.8 and (ii) a polyol-containing component or an amine-containing component or a blend thereof; and wherein the chain-extender is selected from the group consisting of amine-terminated chain-extenders, hydroxyl-terminated chain-extenders, and mixtures thereof. The ICA may comprise a reaction product of hexamethylene diisocyanate (HDI), at least one monoalcohol, and a bismuth-containing catalyst. The ICA may have an average equivalent weight of from about 200 to about 350; and the prepolymer may have an average equivalent weight of from about 420 to about 840. The cover has a thickness of at least about 0.010 in. and a flexural modulus of about 10,000 psi or greater.
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BACKGROUND
[0001] Many spa and other bathing installations include an illumination source for illuminating the body of water in the spa tub or bathing installation container, or adjacent areas or features. Exemplary light sources include LED, incandescent and fiber optic light systems.
[0002] Installation of the light source in the spa tub or bathing installation enclosure or other support structure is typically a time-consuming task.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 is an isometric partially exploded view of an exemplary embodiment of a light assembly for a spa installation.
[0004] FIG. 2 is a top view of the light assembly of FIG. 1 .
[0005] FIG. 3 is a cross-sectional view of the light assembly of FIGS. 1-2 , taken along line 3 - 3 of FIG. 2 .
[0006] FIG. 4 is a cross-sectional view taken along line 4 - 4 of FIG. 3 .
[0007] FIG. 5 is an enlarged view of the area within phantom line 5 of FIG. 3 .
[0008] FIG. 6 is a cross-sectional view of an alternate embodiment of a housing for a light assembly.
[0009] FIG. 7 is a top view of the embodiment of FIG. 6 .
[0010] FIG. 8 is a cross-sectional view of another alternative embodiment of a light assembly.
[0011] FIG. 9 is a top view of the embodiment of FIG. 8 .
[0012] FIGS. 10 and 11 depict a spa waterfall structure employing light assemblies as depicted in FIGS. 8-9 .
DETAILED DESCRIPTION
[0013] In the following detailed description and in the several figures of the drawing, like elements are identified with like reference numerals. The figures may not be to scale, and relative feature sizes may be exaggerated for illustrative purposes.
[0014] FIGS. 1-5 illustrate an exemplary embodiment of a light assembly 50 . The assembly 50 may include a housing 60 , a gasket 70 , and an electrically powered light source 80 . In an exemplary embodiment, the light source includes a light emitting diode (LED) or LEDs, although other types of light sources may be used, e.g. incandescent bulbs, or even an optical fiber transmitting light from a light source, e.g. a remotely located light source.
[0015] In an exemplary embodiment, the housing 60 is fabricated of a transparent or translucent material, e.g. polycarbonate or clear ABS. The housing includes a hollow tube or barrel portion 62 , a head portion 64 , and an interference feature 66 which protrudes from the outer periphery of the hollow tube portion 62 spaced from the head by a gap 68 . In an exemplary embodiment, the housing 60 is designed to be interference fitted into a bore or opening 22 formed in a support structure 20 , e.g., a spa tub wall. For example, the opening may be formed by drilling a hole in the support structure, and may have a circular cross-section. The housing barrel portion 62 and interference feature 66 may have a corresponding circular cross-sectional configuration for this example, with the outer diameter of the housing barrel portion 62 somewhat smaller than the nominal inner diameter of the opening 22 . In an exemplary embodiment, the interference feature 66 may have a generally partial spherical contour, with an outer diameter at its outermost extremity which is somewhat larger than the opening diameter. The outer dimension of the interference feature 66 and the opening dimension are selected so that the housing may be interference fitted into the opening in a tight interference fit.
[0016] In other embodiments, the housing barrel portion 62 and interference feature 66 may have other cross-sectional configurations, e.g. matching non-circular opening configurations. For example, the opening may have a rectilinear configuration, and the housing barrel portion 62 and interference feature 66 may have a matching rectilinear configuration.
[0017] In an exemplary embodiment, the head portion 64 provides a flat seal surface 64 A, against which the gasket 70 is positioned. The gasket in an exemplary embodiment may be fabricated of silicone, EPDM, VITON™, or liquid RTV silicone, preferably of a clear or translucent material. An exemplary gasket thickness range is between 0.030 inch to 0.10 inch, or more preferably 0.030 inch to 0.060 inch.
[0018] The light source assembly 80 may include, in an exemplary embodiment, a light source 82 , which may be an LED source, positioned within the open space 80 within housing barrel portion 62 adjacent the head portion 64 . An o-ring seal may be used to stabilize the position of the light source within the housing. The assembly 80 may also include a circuit board 84 , to which are attached leads 86 which are connected to the light source 82 and leads 88 A- 88 B which may connect to a source of electrical power, or in a daisy chain connection with other light source assemblies. A potting compound may be used to fix the position of the circuit board and seal the electrical components within the housing barrel portion 62 .
[0019] The exposed top surface 64 B ( FIG. 2 ) of the head portion 64 may include a lens pattern, or may be smooth or relatively featureless.
[0020] The light assembly 50 may be readily installed in a support structure such as a wall of a spa tub. An exemplary installation technique may include the steps of (a) forming an opening in the wall, e.g. by drilling a hole, (b) passing the leads 88 A- 88 B through the opening, (c) inserting the housing end 63 into the opening, and (d) pushing assembly 50 into the opening until the head portion and gasket seat against the wall surface 24 . In an exemplary embodiment, the interference feature 66 may be oversized with respect to the opening size such that an impact force may be applied to facilitate the seating of the assembly. For example, the impact force may be applied by a rubber mallet against the outer surface of the head portion 64 . This seating may also compress the gasket 70 between the seal surface 64 A and the surface 24 of the wall, to provide a liquid seal. The gasket portion 70 A ( FIG. 3 ) in the region between the neck region of the housing between the head 64 and the interference portion 66 may be relatively uncompressed, due to the opening gap between the support structure and the housing neck region. This uncompressed portion 70 A may serve to capture the gasket position, keeping the gasket from squeezing out of position or sliding after installation. The interference fit of the feature 66 into the inner surface of the opening 22 may also provide some liquid sealing effect. In an embodiment in which the gasket 70 is formed by a liquid material such as RTV silicone, the gasket material may be dispensed into the opening 22 or onto the outer periphery of the housing 60 , or both, prior to inserting the housing 60 into the opening 22 .
[0021] For some embodiments, e.g., applications in which the LED assembly 50 is above a water line or in which it is unnecessary to provide a water-tight seal, the gasket 70 may be omitted, and the LED assembly installed without a gasket.
[0022] FIG. 5 illustrates the interference fit of the portion 66 and the wall surface of the opening 22 . In the case of a spa tub, the wall may be fabricated of a fiberglass and resin structure, and there may be some compression of the wall to allow the interference portion to enter the opening 22 . Alternatively, the interference portion may also or alternatively compress to allow entry into the opening.
[0023] It may be the case that the opening 22 is formed in the wall 20 at some offset from the perpendicular, or that the wall surface 22 is not completely true or flat. In the past, these types of features or imperfections may lead to difficulties in getting a light fitting head to lie flat against the wall surface. The interference feature 66 may ameliorate these difficulties, by provide some relatively limited range of rotational movement of the head portion within the opening about the interference feature. This is depicted in FIG. 3 , wherein the dashed lines 26 A- 26 B depict the orientation of an opening formed truly perpendicular to the wall surface 24 , and so the actual opening is formed at a small angle offset from the perpendicular. Since in this embodiment the entire outer surface of the barrel portion of the housing is not in intimate contact with the opening wall due to its undersized diameter, the seal surface 64 A may still be seated truly about the perimeter of the opening.
[0024] The housing 60 in an exemplary embodiment may be fabricated by injection molding, or by machining, or by other techniques.
[0025] FIGS. 6-7 illustrate an alternate embodiment of a housing structure 160 for a light assembly. In this exemplary embodiment, which may be machined from a cylindrical rod of transparent material such as polycarbonate or a clear ABS, the exposed head surface 164 B of the head portion 164 is flat. In another embodiment, the housing structure may be molded. The following are exemplary dimensions for this embodiment, although it is to be understood that the particular dimensions are given for the sake of illustration of one embodiment, and that other dimensions may be appropriate for other applications and embodiments. The outer diameter of the head portion 164 is 0.75 inch. The barrel portion 162 has an outer diameter of 0.4 inch, and an inner diameter of 0.344 inch, which is stepped at shoulder 163 to a diameter of 0.295 inch. The interference feature 166 has an outer diameter at its largest dimension of 0.515 inch. A gap dimension 168 between the interference feature and the head seal surface 164 A is 0.062 inch, providing space for a gasket (not shown in FIG. 6 ). The length of the tube portion 162 between end 162 A and shoulder 163 is 0.55 inch, and the overall length of housing 160 in this embodiment is 1.055 inch. In an exemplary embodiment, the housing structure with these exemplary dimensions is adapted for installation in a nominal wall opening of ½ inch, with a nominal wall thickness of 3/16 inch or more.
[0026] The shoulder 163 of the housing structure 160 may provide a stop surface against which may be seated a circuit board assembly or other structure for a light source, for example.
[0027] FIGS. 8-11 illustrate another alternate embodiment of a housing structure 200 for a light source. The housing structure 200 is designed to be installed from the opposite direction from that of housing structures 60 and 160 . Thus, while housing structures 60 and 160 may be installed in a wall opening by inserting the end 63 or 162 A of the tube portion 60 or 160 into the wall opening, housing structure 200 may be installed in an opening 304 in a support structure 302 by first inserting the head portion 204 into the opening.
[0028] As with the housing structures 60 and 160 , the structure 200 includes a hollow tube portion 202 , a head portion 204 and an interference feature 206 . In this embodiment, the housing structure 200 further includes a flange portion 210 spaced from the interference feature 206 by a gap 208 . A flange surface 210 A provides a seal surface against which a gasket 220 will be seated when the housing structure is installed in a support structure. As with the housing structures 60 and 160 , a light source assembly 230 may be installed within the hollow space inside the housing structure, with connection leads extending from the end 202 A of the hollow portion 202 .
[0029] An assembly including the housing structure 200 may be installed into an opening in a support structure. The opening is undersized relative to the outer dimension of the interference feature 206 . An exemplary installation procedure includes inserting the head portion 204 into the opening, and applying an insertion force against the housing structure, e.g. on flange surface 210 B, to force the interference feature into the opening, until the gasket and seal surface 210 A are seated against the surface of the support structure surrounding the opening. For example, the insertion force may be applied by a rubber mallet, striking either end 202 A or against an end of a pipe inserted over the tube portion with its distal end seated against the flange surface 210 B.
[0030] One exemplary application for use of a light assembly including the housing structure 200 is illustrated in FIGS. 10-11 . A waterfall structure 300 may be mounted adjacent a spa tub, and connected to a water supply, which results in a waterfall action from an outlet 304 and slot 306 . The structure 300 includes a wall 302 , into which openings are formed to receive the light assembly housing structures 200 . The embodiment of FIGS. 10-11 depicts four housing structures, although more or less light assemblies may be employed as desired for a given application. To install the housing assemblies 200 , the head of each may be inserted into the opening surface 302 A ( FIG. 10 ), and an insertion force applied to overcome the interference due to the interference feature 206 , until the gasket 220 and seal surface 210 A are engaged against the surface 302 A.
[0031] Although the foregoing has been a description and illustration of specific embodiments of the invention, various modifications and changes thereto can be made by persons skilled in the art without departing from the scope and spirit of the invention as defined by the following claims.
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A fitting adapted for installation into an opening of a support structure includes a housing structure having a longitudinal extent with a head region. An exemplary embodiment of the housing structure has an interference feature whose outer shape configuration generally matches a shape configuration of the opening, the interference feature oversized relative to the opening. The housing structure further includes a seal surface disposed generally transverse to the longitudinal extent. A component such as a light source may be disposed within the housing structure.
A method for installing a light fixture in an opening formed in a support structure includes positioning an end of the light fixture in the opening, applying an installation force on the light fixture to advance the light fixture into the opening such that an oversized interference feature on the exterior periphery of the light fixture tightly engages interior surfaces defining the opening in the support structure, and pushing the light fixture into the opening to engage a seal surface of the light fixture in engagement with a support structure surface around the opening.
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FIELD OF THE INVENTION
The invention relates to a procatalyst composition for an α-olefin polymerization catalyst, the composition comprising a magnesium dihalide carrier and thereon a compound of tetravalent titanium and an electron donor, the electron donor being a mono- or polyester of an unsaturated polycarboxylic acid in which at least two carboxyl groups are joined to contiguous carbon atoms which form double bonds.
BACKGROUND OF THE INVENTION
α-olefins are often polymerized using a Ziegler-Natta catalyst system made up of a so-called procatalyst and a cocatalyst. Of these, the procatalyst component is based on a compound of a transition metal belonging to any of Groups IVA-VIII in the Periodic Table of the Elements, and the cocatalyst component is based on an organometallic compound of a metal belonging to any of Groups IA-IIIA in the Periodic Table of the Elements (the groups are defined according to Hubbard, i.e. IUPAC). The catalyst system may also include a carrier on which the transition-metal compound is deposited and an internal electron donor which enhances and modifies the catalytic properties and is deposited on the carrier together with the transition-metal compound. In addition, a separate so-called external electron donor can also be used together with the procatalyst and the cocatalyst.
In the preparation of stereoselective high-yield Ziegler-Natta catalysts on a magnesium dihalide, organic esters are widely used as internal donors to improve the said properties of the catalyst. Publications U.S. Pat. No. 4,522,930, EP-45 977 and FI-70 028 describe an α-olefin polymerization catalyst obtained by causing a cocatalyst, an external donor and a carrier-based procatalyst to react together. The procatalyst is made up of a titanium compound deposited on a magnesium dihalide carrier and of an internal electron donor. The internal donor may be any of the following (summary of the above state of the art):
1) saturated dicarboxylic acid ester,
2) unsaturated polycarboxylic acid ester,
3) aromatic di- or polycarboxylic acid ester,
4) aromatic oligohydroxy compound ester,
5) monocarboxylic acid ester,
6) araliphatic polycarboxylic acid ester,
7) heterocyclic aromatic polycarboxylic acid ester,
8) carbonic acid ester,
9) polyol or monohydroxyphenol ester,
10) acetylenic acid ester.
Regarding group 2) it is stated that the two carboxyl groups may, or may not, be linked to contiguous carbon atoms which form double bonds. As an example of internal electron donors of the former type, publications FI-70 028 and EP-45 977 mention the compounds di-2-ethyl-hexyl maleate, di-isobutyl maleate, di-isobutyl-3,4-furan-dicarboxylate, di-2-ethyl-hexyl fumarate, 2-ethyl-hexyl fumarate, and 2-ethyl-hexyl monomaleate. In addition, the FI publication states that the esters of maleic, pivalic, carbonic, and phthalic acids are especially advantageous internal donors.
According to Table I of the FI and EP publications, the activity of maleates is, however, only about one-half of the activity of phthalates, and thus there is very little use for them in commercial processes. By the same criteria it can be concluded that the di-butyl-itaconate presented in the table of the US publication is not a practicable internal donor, either.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a maximally active procatalyst composition for a polymerization catalyst. The invention at the same time aims at a procatalyst composition which yields a maximally tactic polymer. A further aim is that the polymer produced should have a suitable morphology, bulk density, and melt index.
These objectives have now been achieved with a procatalyst combination for an α-olefin polymerization catalyst, the procatalyst combination being is primarily characterized in what is stated in the characterization clause of claim 1. It has thus been realized that, if the electron donor used is a mono- or polyester of an unsaturated polycarboxylic acid in which at least two carboxyl groups are joined to contiguous carbon atoms forming double bonds, at least one of the said carbon atoms of the electron donor, or a carbon atom joined thereto by a double bond, is to be substituted by a hydrocarbon group having 1-20 carbon atoms.
The invention is thus based on the surprising observation that hydrocarbon groups in the vicinity of the carboxyl groups and double bonds in unsaturated polycarboxylic acids have a greatly increasing effect on catalyst activity.
DETAILED DESCRIPTION OF THE INVENTION
The procatalyst composition according to the invention comprises a magnesium dihalide carrier and thereon a compound of tetravalent titanium and an electron donor. The magnesium dihalide carrier is preferably magnesium dichloride. The tetravalent titanium compound may be a titanium alkoxide, a titanium alkoxide halide, or a titanium halide. Preferably it is titanium tetrachloride.
According to one preferred embodiment, the magnesium dihalide carrier and the compound of tetravalent titanium and the electron donor thereon are prepared by melting magnesium dichloride together with a lower alcohol, such as ethanol, and possibly an internal donor, to produce a molten homogeneous mixture, which is then formed by physical means into small active particles of carrier material. Substantially spherical carrier particles can, for example, be prepared by spray-crystallizing the said melt in accordance with U.S. Pat. No. 4,829,034.
Thereafter the carrier particles are activated by contacting them with a compound of tetravalent titanium and possibly at this stage also with an internal donor. Often a repeat treatment with the compound of tetravalent titanium is carried out in order to produce a maximally active procatalyst.
As stated above, in the electron donor at least one of the carbon atoms forming double bonds or joined thereto by a double bond is substituted by a hydrocarbon group having 1-20 carbon atoms. In this case it is advantageous if the electron donor is a maleic or fumaric acid ester substituted with the said hydrocarbon group. According to one preferred embodiment, the electron donor is a maleic acid diester monosubstituted with the said hydrocarbon group. In this case it is most preferable that it is dialkyl cis-2-methyl-butenedioic acid ester with 1-10 carbon atoms in its alkyl. Some such compounds are:
DEMB=diethyl cis-2-methyl-butenedioic acid ester,
DIBMB=di-isobutyl cis-2-methyl-butenedioic acid ester,
DDMB=didecyl cis-2-methyl-butenedioic acid ester.
It has been observed that a procatalyst composition according to the invention works very well if its electron donor/magnesium molar ratio is within a range of approx. 0.050-0.50. Its Al/Ti molar ratio is preferably within a range of approx. 500-1000, and its Al/electron donor molar ratio is preferably within a range of approx. 10-30. The preparation of catalysts according to the invention and their use for the polymerization of propylene are described in the following examples. The steps of catalyst preparation are identical in all the examples, unless otherwise indicated. There are 6 embodiment examples and 4 comparison examples, namely BCDE. The purpose of the comparison examples is to make a comparison between nonsubstituted unsaturated diesters, such as dialkyl maleates, and substituted unsaturated diesters according to the present invention.
The following abbreviations are used in the examples and the tables:
DEMB=diethyl cis-2-methyl-butenedioic acid ester,
DIBMB=di-isobutyl cis-2-methyl-butenedioic acid ester,
DDMB=didecyl cis-2-methyl-butenedioic acid ester,
DEME=diethyl maleate,
DIBME=di-isobutyl maleate,
DDME=didecyl maleate.
EXAMPLE 1
Activation of a MgCl 2 *3EtOH carrier was performed as follows:
24.5 g of the above-mentioned carrier, prepared in accordance with U.S. Pat. No. 4,829,034, is added at -10° C. into a vessel containing 150 ml of heptane and 300 ml of TiCl 4 . The carrier is allowed to react while the temperature is raised slowly to +20° C., with mixing. At this temperature, 1.9 ml of DIBMB is added, i.e. the DIBMB/Mg molar ratio is 0.075, and the temperature is raised within 60 minutes to +110° C. and is maintained at that level for 60 minutes. The treatment is repeated with 300 ml of TiCl 4 at +120° C. for 60 minutes. The product is washed with 300 ml of heptane at 80° C. for 20 minutes. The washing is repeated five times, and the product thus obtained is dried in a nitrogen stream at room temperature.
The dried procatalyst was brown, and the following analytical results were obtained regarding it:
Ti 3.1% by weight; Mg 16.7% by weight; Cl 58.0% by weight; DIBMB 9.7% by weight; heptane 12.5% by weight.
The polymerization was carried out in a two-liter autoclave by using 900 ml of heptane as the medium:
P(C 3 H 6 )=7 bar
AlEt 3 , 5 mmol; Al/Ti=737
P(H 2 )=0.3 bar
Al/electron donor=20
T=+70° C.
Catalyst quantity=25.0 mg
t=4 h
Triethyl aluminum was used as the cocatalyst and cyclohexyl-methyl-dimethoxysilane was used as the electron donor. The activity of the catalyst was 529 kg polypropylene per g Ti and 18.7 kg PP/g dry catalyst.
The evaporation residue obtained from the polymerization fluid was 0.7% by weight, calculated from the total polypropylene quantity. The isotacticity of the polypropylene was 97.2%, its isotactic index 96.5%, and its relative density 0.47 g/cm 3 . The melt index of the polymer was 6.2 g/10 min (see Tables 1 and 2 ).
EXAMPLES 2-4
The preparation of the catalyst was performed exactly as in Example 1 by using the carrier mentioned above, but the DIBMB/Mg molar ratios were 0.125, 0.175 and 0.350 (in examples 2, 3 and 4, respectively). The analytical results of the catalysts are shown in Table 1.
Propylene polymerization was performed as in Example 1 (25.0 mg of procatalyst, 5 mmol of AlEt 3 and an Al/electron donor molar ratio of 20 were used). The results of the polymerization are shown in Table 2.
EXAMPLE 5
The preparation of the catalyst was performed exactly as in Example 1 by using the carrier mentioned above, but DEMB was used instead of DIBMB as the internal donor. The DEMB/Mg molar ratio in the procatalyst synthesis was 0.075. The analytical results of the procatalysts obtained are shown in Table 1.
Propylene polymerization was performed as in Example 1 (25.0 mg of catalyst, 5 mmol of AlEt 3 , and Al/electron donor molar ratio 20). The polymerization results are shown in Table 2.
EXAMPLE 6
The preparation of the catalyst was performed exactly as in Example 1 by using the carrier mentioned above, but DDMB instead of DIBMB was used as the electron donor. The DDMB/Mg molar ratio in the procatalyst synthesis was 0.104. The analytical results of the procatalysts are shown in Table 1.
Propylene polymerization was performed as in Example 1 (25.0 mg of procatalyst, 5 mmol of AlEt 3 , and Al/electron donor molar ratio 20). The polymerization results are shown in Table 2.
COMPARISON EXAMPLE A
The preparation of catalyst was performed exactly as in Example 1, by using the same carrier, but no electron donor was used. The analytical results were: Ti 7.2% by weight; Mg 14.2% by weight; Cl 57.2% by weight; heptane 21.4% by weight.
Propylene polymerization was performed as in Example 1. The activity of the catalyst was 149 kg polypropylene per g Ti. The evaporation residue from the polymerizing fluid was 15.3% by weight, calculated from the total polypropylene quantity obtained. The isotacticity of the polypropylene was 91.7% and its isotactic index 77.7%. Specific density was not measured, since the polypropylene was sticky owing to amorphousness. The melt index of the polymer was 3.0 g/10 min.
COMPARISON EXAMPLES B, C, D AND E
The preparation of the catalyst was performed exactly as in Example 1, by using the same carrier, but di-isobutyl maleate (DIBME) instead of DIBMB was used as the internal donor. The DIBME/Mg molar ratios were 0.075, 0.125, 0.175, and 0.350. The analytical results of the procatalysts obtained are shown in Table 1. Propene polymerization was performed as in Example 1, and the polymerization results are shown in Table 3.
TABLE 1______________________________________Type and quantity of the donor used in synthesis,and analytical compositions of the catalysts (in % by weight) Donor/Mg Donor/mlExample molar ratio added Ti Mg Cl Donor______________________________________1 0.075 DIBMB 3.1 16.7 58.2 9.7 1.92 0.125 DIBMB 2.4 18.5 61.2 7.5 3.23 0.175 DIBMB 2.2 15.9 53.0 9.1 4.54 0.35 DIBMB 5.7 15.1 61.0 23.0 8.95 0.075 DEMB 1.7 15.9 51.5 10.7 1.56 0.104 DDMB 3.1 16.8 58.3 13.8 4.4Comp. B 0.0750 DIBME 2.2 12.9 56.2 5.4 1.8Comp. C 0.125 DIBME 2.5 16.7 56.2 8.3 3.1Comp. D 0.175 DIBME 2.5 17.8 59.4 9.6 4.4Comp. E 0.35 DIBME 5.7 11.9 51.7 21.5 8.8______________________________________
TABLE 2______________________________________Performance of the catalysts in propylenepolymerization carried out in a heptane slurry byusing internal donors in accordance with the invention Activity in kg Activity PP/g of Isotacticity/ in kg dry cat- evaporation I.I.Example PP/g Ti alyst residue (%) B.D. M.I.______________________________________1 529 18.7 97.2/0.7 96.5 0.47 6.22 592 16.1 98.2/0.7 97.5 0.39 8.53 595 16.3 98.3/0.6 97.7 0.37 12.54 204 11.6 98.7/0.7 98.0 0.41 12.05 876 18.7 98.6/1.1 97.5 0.39 2.26 574 19.5 95.8/0.9 94.9 0.43 6.3______________________________________
TABLE 3______________________________________Performance of procatalysts in propylenepolymerization carried out in a heptane slurry usingas the internal donor DIBME, a compound in accordancewith the state of the art Activity in kg Activity PP/g of Isotacticity/ in kg dry cat- evaporation I.I.Example PP/g Ti alyst residue (%) B.D. M.I.______________________________________Comp. B 559 12.3 97.1/1.3 95.8 0.45 8.0Comp. C 372 9.3 97.1/1.1 96.0 0.40 14.4Comp. D 147 6.0 97.7/1.4 96.3 0.39 14.1Comp. E 37 1.6 96.8/7.0 89.8 0.31 13.0______________________________________
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It is known that an electron donor together with a compound of tetravalent titanium on a magnesium halide carrier is usable if it is a mono- or polyester of an unsaturated polycarboxylic acid in which at least two carboxyl groups are joined to contiguous carbon atoms which form double bonds. It has now been observed that activity and stereospecificity increase if at least one of the said carbon atoms, or a carbon atom joined thereto by a double bond, is substituted by a hydrocarbon group having 1-20 carbon atoms. Maleic and fumaric acid esters substituted with the said hydrocarbon group can be mentioned as examples.
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BACKGROUND OF THE INVENTION
This invention relates to a process and a chemical plant for the production of paraxylene. In particular the process and chemical plant utilise zeolite membranes for enhanced paraxylene production.
In the petrochemical production chain one of the most important streams is the C 6 to C 8 aromatics stream which is a source of raw materials for high value downstream products. From this stream, benzene, toluene and the C 8 aromatics which are particularly valuable may be obtained. The C 8 aromatics are orthoxylene, metaxylene, paraxylene and ethylbenzene. Paraxylene is often the most desirable of the xylenes; however because the boiling points of ethylbenzene, ortho-, meta- and paraxylene (hereinafter collectively referred to as “C 8 aromatics”) are close, they are difficult to separate by fractional distillation. As a consequence various alternative methods of separating paraxylene from C 8 aromatics have been developed. The most common of such methods are fractional crystallisation which utilises the difference in freezing points between ethylbenzene, ortho-, meta- and paraxylene, and selective adsorption which commonly utilises zeolite materials to selectively adsorb paraxylene from C 8 aromatics streams; the adsorbed paraxylene is recovered after desorbing from the zeolite. When either of these processes are used paraxylene can be recovered in high yields from the C 8 aromatics stream. The resulting filtrate from the crystallisation process or the raffinate from the adsorption process are depleted in paraxylene and contain relatively high proportions of ethylbenzene, ortho-, and metaxylene. These streams are typically subjected to further processing downstream of the crystallisation or adsorption process.
Typically one of the additional downstream processes is an isomerisation process which is used to increase the proportion of paraxylene in paraxylene depleted streams from such processes as fractional crystallisation or selective adsorption. The xylenes, which are predominantly ortho-and metaxylene, can be contacted with an isomerisation catalyst under appropriate temperature and pressure which results in the conversion of some of the ortho- and metaxylene to paraxylene. It is also usually necessary to convert some of the ethylbenzene to prevent it from building up to high concentrations. A catalyst can be selected to enable conversion of ethylbenzene to benzene, and/or to orthoxylene through a C 8 naphthene intermediate and/or to C 10 aromatics and benzene via transalkylation. It may be that the catalyst for conversion of ethylbenzene to orthoxylene is also a xylenes isomerisation catalyst in which case the orthoxylene from the ethylbenzene is converted to an equilibrium mixture of xylenes.
Prior art processes for making paraxylene have typically included combinations of isomerization with fractional crystallisation and/or adsorption separation. The problem with this combination is that despite improvements in catalyst performance the isomerisation technology is only able to produce equilibrium or near-equilibrium mixtures of xylenes and may also be relatively inefficient for the conversion of ethylbenzene to benzene or xylenes. The consequence of this is that big recycles of the xylenes stream back through these processes are needed to ensure the conversion of the C 8 aromatics stream to paraxylene is maximised with or without the additional recovery if desired of orthoxylene and/or metaxylene. There is a need therefore for improved processes and chemical plants for the production of paraxylene from C 8 aromatics streams, which in particular address the problems associated with large recycles and/or low ethylbenzene conversions.
Zeolite membranes have been described in the prior art, for example in U.S. Pat. No. 4,699,892, U.S. Pat. No. 5,100,596, EP 0481658, EP 0481659, EP 0481660, WO 92/13631, WO 93/00155, WO 94101209, and WO 94/25151. However the prior art does not describe how to use such membranes in actual C 8 aromatics processing in the petrochemical cycle nor does the prior art describe how to use such membranes in combination with existing processes to significantly enhance their paraxylene production capability
SUMMARY OF THE INVENTION
The present invention is therefore directed to a chemical plant and process which offers an improvement over the prior art for the production of paraxylene from C 8 aromatics streams. The present invention resides in the specific application of a zeolite membrane unit and process in a paraxylene or paraxylene with orthoxylene and/or metaxylene recovery process. This invention utilises zeolite membranes to continuously separate paraxylene and/or ethylbenzene from xylenes, or to isomerise ortho- and metaxylene to paraxylene and/or ethylbenzene to xylenes and simultaneously or subsequently separate paraxylene from the xylenes mixture. The use of a zeolite membrane unit and process in for example a process for paraxylene recovery provides for a significant improvement in paraxylene production when compared to conventional paraxylene recovery processes.
Accordingly the present invention provides a process for recovering paraxylene from a C 8 aromatics stream containing paraxylene and at least one other isomer of xylene, ethylbenzene, or mixtures thereof which process comprises:
(a) recovering by means of a paraxylene separation process in a paraxylene recovery unit a portion of said paraxylene from at least a portion of said C 8 aromatics stream to produce a first stream having a reduced paraxylene content and containing at least a portion of said other isomers of xylene, said ethylbenzene, or mixtures thereof;
(b) passing at least a portion of said first stream directly or indirectly to a zeolite membrane unit comprising a zeolite membrane and optionally isomerisation catalyst under isomerization conditions, such that the permeate withdrawn through the zeolite membrane and from the zeolite membrane unit is enriched in is paraxylene when compared to the feed to the zeolite membrane unit and
(c) feeding the permeate directly or indirectly back to the paraxylene separation process.
Preferably there is an additional step between (a) and (b) wherein at least a portion of said first stream is subjected to an isomerisation process in an isomerisation unit to produce an isomerate having an enriched paraxylene content compared to that of the first stream; and it is at least a portion of this isomerate stream which is passed to the zeolite membrane unit. Most preferably the permeate withdrawn from the zeolite membrane unit is enriched in paraxylene compared to the equilibrium concentration of paraxylene in a xylenes equilibrium mixture.
The present invention further provides for a paraxylene recovery plant comprising:
(a) paraxylene recovery unit, and
(b) a zeolite membrane unit comprising a zeolite membrane and optionally isomerisation catalyst.
Preferably the paraxylene recovery plant comprises an isomerisation unit in addition to the paraxylene recovery unit and zeolite membrane unit.
DETAILED DESCRIPTION OF THE INVENTION
The paraxylene recovery unit uses separation technology to produce a paraxylene enriched stream and a paraxylene depleted stream. Such separation technology includes for example the known processes of fractional crystallisation, or selective adsorption using for example molecular sieve absorbers. The paraxylene recovery unit may therefore be a fractional crystallisation unit which utilises the difference in freezing points between ethylbenzene, ortho-, meta- and paraxylene or it may be a selective adsorption unit which commonly utilises zeolite materials to selectively adsorb paraxylene from C 8 aromatics streams; the adsorbed paraxylene is recovered after desorbing from the zeolite. The paraxylene recovery unit may also be a combination of such separation units, or may incorporate other less commonly used techniques such as fractional distillation.
Fractional crystallisation units are well known in the art and are described for example in U.S. Pat. No. 4,120,911. Commercially available processes include the crystallisation Isofining process, direct contact CO 2 crystallisers, scraped drum crystallisers, and continuous countercurrent crystallisation processes. The crystalliser may operate for example in the manner described in Machell et. al. U.S. Pat, No. 3,662,013. Commercial fractional crystallisation processes typically recover about 60% to 68% of the paraxylene from the feed to the paraxylene recovery unit when this feed is an equilibrium or near equilibrium mixture of xylenes and ethylbenzene. The reason for this is that they are limited by the formation of a eutectic between paraxylene and metaxylene However the actual recovery depends on the composition of the feed with higher recoveries possible when the paraxylene content of the feed is higher than the xylenes equilibrium content.
Selective adsorption units are also well known in the art and are described for example in U.S. Pat. No. 3,706,812, U.S. Pat. No. 3,732,325, U.S. Pat. No. 4,886,929, and references cited therein, the disclosures of which are hereby incorporated by reference. Commercially available processes include UOP PAREX™, and IFP-Chevron ELUXYL™ processes. Commercial molecular sieve selective adsorption processes may recover higher levels of paraxylene than fractional crystallisation processes; typically they recover over 90% or more typically over 95% of the paraxylene from the feed to the paraxylene recovery unit.
The paraxylene recovery unit produces a paraxylene enriched stream that usually comprises over 99% and may even be as high as 99.9% paraxylene. The exact amount depends on the process used and the design and operating conditions of the specific plant. The balance in this stream being ethylbenzene, ortho-, and metaxylene, toluene, and C 9 aromatics, paraffin's, naphthenes and possibly small amounts of other materials. The paraxylene recovery also produces a paraxylene depleted stream containing the balance of ethylbenzene, ortho-, and metaxylene, toluene, C 9 aromatics, paraffins, etc. along with any paraxylene fed to the paraxylene recovery unit that is not removed in the paraxylene rich stream. It is this paraxylene depleted stream which is then fed to the isomerisation unit and/or zeolite membrane unit.
The C 8 aromatics stream which is used as the feed for the paraxylene separation unit may come from a variety of sources in the petrochemical plant. One possible source Is from naphtha reforming. Examples of such processes include Exxon POWERFORMING™, UOP Platforming™, IFP Aromizing™. Another possible source is pyrolysis gasoline from steam cracking processes although this is likely to be a minor source of such streams. A further possible source is the UOP Cyclar process for conversion of C 3 /C 4 hydrocarbon streams to aromatics (see for example U.S. Pat. No. 5,258,563, the disclosure of which is hereby incorporated by reference). A further possible source is from toluene disproportionation and/or C 9 aromatics transalkylation. Examples of such processes include UOP TATORAY™, TORAY TAC9™, Mobil Selective Toluene Disproportionation™ (MSTDP), Mobil Toluene Disproportionation™ (MTDP), IFP Xylenes PLUS™ and FINA T2BX™. There are other possible sources of C 8 aromatics streams. The source of C 8 aromatics stream for the process of the present invention is not critical and may be a single stream or may be a combination of streams from any of the above processes.
The isomerisation unit may be any of the well known units in the art such as those described in U.S. Pat. No. 4,236,996, U.S. Pat. No. 4,163,028, U.S. Pat. No. 4,188,282, U.S. Pat. No. 4,224,141, U.S. Pat. No. 4,218,573, U.S. Pat. No. 4,236,996, U.S. Pat. No. 4,899,011, U.S. Pat. No. 3,856,872 and Re. 30,157, the disclosures of which are hereby incorporated by reference.
The isomerisation catalyst may be any of the well known catalysts for isomerisation units in the art. There are primarily two types of catalyst system which are used in isomerisation units. The choice of catalyst has an impact on the overall yield and structure of the aromatics complex and also on the plant design and economics. The first type of catalyst is designed to convert ethylbenzene to xylenes and to isomerise the paraxylene depleted feed stock to a near equilibrium xylene composition. This type of catalyst system is generally the choice for aromatics producers whose objective is to maximise para and ortho-xylene production from a fixed quantity of feed stock. A second catalyst system is also designed to isomerise the para xylene depleted feed stock; however rather than converting ethylbenzene to xylenes, this catalyst system dealkylates the ethylbenzene to produce benzene. This catalyst system is often employed when the benzene requirements are high relative to ortho and para xylene production or when feed stock availability is not a limiting factor.
Examples of processes and catalyst systems which include the capability of converting ethylbenzene to benzene are the Mobil MHTI (Mobil High Temperature Isomerisation) process and catalyst (see for example U.S. Pat. No. 3,856,871 and U.S. Pat. No. 4,638,105, the disclosures of which are hereby incorporated by reference), the Mobil MHAI (Mobil High Activity Isomerisation) process and catalyst, the AMOCO AMSAC process and catalyst and the UOP ISOMAR™ 1-100 process and catalyst.
Examples of processes and catalyst systems which include the capability of converting ethylbenzene to xylenes are the IFP/ENGELHARD Octafining and Octafining II processes and catalyst, and the UOP ISOMAR™ 1-9 process and catalyst. Other processes include catalysts capable of converting ethylbenzene to C 10 aromatics. Other processes do not include ethylbenzene conversion.
Isomerization units typically use a zeolite or mordenite type catalyst. Isomerization catalysts known to promote conversion of ortho and metaxylene to paraxylene include metal promoted molecular sieves such as for example Pt Promoted ZSM-5, Pt promoted Mordenite and metal promoted borosilicates etc. Commercial examples are Mobil MHAI and ISOMAR™ 1-9 catalyst.
The isomerization reactor is arranged and effective to isomerise ortho- and metaxylene to paraxylene at these conditions and also advantageously to convert ethylbenzene to benzene and/or xylenes. The term “arranged and effective” is used in this application to denote that conditions in a process unit are as described in this specification to include the temperatures, pressures, space velocities, reaction time, other reactants, and any other process conditions necessary to achieve the desired reaction, conversion or separation that is the normal function of that process unit.
Operating temperatures are typically in the range of 400 to 900° F. and pressures in the range of 25 to 500 PSIG The weight hourly space velocity (WHSV) based on hydrocarbon feed typically ranges from 0.5 to 20. Most isomerization catalyst systems require a source of hydrogen which can be introduced to the isomerization reactor to promote the isomerization reaction that converts ortho- and metaxylene to paraxylene, to assist in the conversion of ethylbenzene to benzene and or xylenes and assists also in the prevention of coking of the isomerisation catalyst.
In one aspect of the present invention the zeolite membrane unit is used to selectively separate paraxylene and/or ethylbenzene from a stream which comprises ethylbenzene and an equilibrium or near equilibrium mixture of xylenes. In this aspect the zeolite membrane unit may be located downstream of an isomerisation unit and does not have an isomerisation catalyst in combination with the membrane.
In a further aspect of the present invention, a zeolite membrane unit utilises an isomerisation catalyst in combination with the membrane to isomerise ortho- and metaxylene to paraxylene in co-operation with the selective separation function of the membrane and may also include the catalytic conversion of ethylbenzene to benzene or xylenes.
In this aspect of the present invention the zeolite membrane may itself be rendered catalytically active for the isomerisation reaction or an appropriate isomerisation catalyst may be located proximate to the membrane. By proximate to the membrane is meant that the catalyst is arranged and effective to isomerise the ortho- and/or metaxylene and/or ethylbenzene in the material in the zeolite membrane unit but upstream of the zeolite membrane to produce paraxylene. The exact amount of paraxylene which is required to be produced by the isomerisation process in the zeolite membrane unit depends in part on the properties of the zeolite membrane used. If the membrane for example has high flux and/or high selectivity for paraxylene then it may be possible or even desirable for the isomerisation reaction to produce and maintain paraxylene at a non equilibrium concentration compared to its concentration in an equilibrium xylene mixture whilst the membrane selectively removes paraxylene from the upstream material and into the permeate. However the isomerisation catalyst in the zeolite membrane unit should ideally be arranged and effective to produce and maintain paraxylene, upstream of the membrane and inside the zeolite membrane unit, at 50% or more, preferably 80% or more, and most preferably 90% or more of the paraxylene equilibrium concentration whilst the membrane selectively removes paraxylene from the upstream side of the membrane and into the permeate. Depending on membrane properties it may be desirable and preferable to maintain the paraxylene concentration at or near to equilibrium for xylenes isomerisation which the membrane selectively removes paraxylene from the retentate into the permeate. Thus the isomerisation catalyst causes the ortho-, and metaxylene to convert to paraxylene and the paraxylene selectively permeates through the zeolite membrane to be produced as a permeate stream. Ortho- and metaxylene less readily pass through the zeolite membrane and tend to stay on the upstream side in the retentate stream where they can be further isomerised. The permeate stream from xylenes isomerisation unit may be fractionated to remove materials boiling below and above the boiling point of xylenes e.g. benzene, toluene and C9+ aromatics and then transferred to the paraxylene recovery unit. If the zeolite membrane unit is particularly efficient at isomerisation -and separation there may theoretically be no retentate stream as there would be no paraxylene depleted stream to reject. In practice there will however likely be impurities and heavier aromatic compounds such as C 9 aromatics which remain in the retentate stream and must be purged from the zeolite membrane unit for further treatment. Thus in the zeolite membrane unit there is a dynamic and coupled process of isomerisation and separation of xylenes. If the catalytic function is also capable of converting ethylbenzene to benzene or xylenes then any ethylbenzene which enters into the retentate stream of the unit is also involved in this dynamic process with the resulting xylenes entering into the xylenes isomerisation reactions or the resulting benzene passing through the membrane into the permeate stream. In this aspect the zeolite membrane unit may be downstream of an isomerisation unit or may be used in place of an isomerisation unit.
In a further aspect the zeolite membrane is used to selectively separate ethylbenzene with a small amount of paraxylene from a paraxylene depleted feedstream as is typically found after a paraxylene separation process. In this aspect the zeolite membrane unit is located between the paraxylene separation unit and an ethylbenzene isomerisation unit. The feed to the isomerisation unit is enriched in ethylbenzene and improves the efficiency of the ethylbenzene isomerisation process in this unit. The output from this isomerisation unit is enriched in paraxylene and passes into a conventional paraxylene isomerisation unit along with the retentate from the zeolite membrane unit. In such a process the paraxylene isomerisation unit is required to convert lower levels of ethylbenzene and therefore may be operated at lower temperatures and may in fact be a liquid phase isomerisation unit which has no ethylbenzene conversion activity. The overall effect of this use of the zeolite membrane is to enhance the conversion of ethylbenzene to useful xylenes and to significantly reduce the xylene losses which usually occur due to the use of high temperature isomerisation units such as ISOMAR™ or MHTI™. A further modification of this aspect of the present invention is to include a catalytic function into the zeolite membrane unit. This catalytic function may be for ethylbenzene conversion and may be located within the membrane itself. This catalytic function may advantageously be located proximate to the membrane on the permeate side of the zeolite membrane. The function of this catalyst is to catalyse the conversion of ethylbenzene to xylenes. The effect of this is to deplete the concentration of ethylbenzene on the permeate side of the membrane and in doing so sets up a concentration gradient across the membrane which increases the quantity of ethylbenzene transferred from the retentate stream into the permeate stream. If the ethylbenzene conversion catalyst in the zeolite membrane unit is particularly efficient there may be no need for the ethylbenzene isomerisation unit which is located downstream of the zeolite membrane unit. In a further embodiment a second zeolite membrane unit for selective paraxylene separation or for selective paraxylene separation and isomerisation, may be located downstream of the paraxylene Isomerisation unit. The permeate stream from xylenes isomerisation unit or the second zeolite membrane unit if present may be fractionated to remove materials boiling below and above the boiling point of xylenes e.g. benzene, toluene and C9+ aromatics and then transferred to the paraxylene recovery unit. Optionally, the retentate stream may be combined with the permeate stream and the combined streams fractionated and transferred to the paraxylene recovery unit for recovery of a paraxylene rich stream.
Examples of zeolite membranes which may be used in zeolite membrane units for the present invention are described in the following documents. U.S. Pat. No. 5,110,478, the disclosure of which is hereby incorporated by reference, describes the direct synthesis of zeolite membranes. The membranes produced in accordance with the teachings of U.S. Pat. No. 5,110,478 were discussed in “Synthesis and Characterisation of a Pure Zeolite Membrane,” J. G. Tsikoyiannis and W. Haag, Zeolites (VOI. 12, p. 126., 1992) Such membranes are free standing and are not affixed or attached as layers to any supports. Zeolite membranes have also been grown on supports. See e.g. “High temperature stainless steel supported zeolite (MFI) membranes: Preparation, Module, Construction and Permeation Experiments,” E. R. Geus, H. vanBekkum, J. A Moulyin, Microporous Materials, Vol. 1, p. 137, 1993; Netherlands Patent Application 91011048; European Patent Application 91309239.1 and U.S. Pat. No. 4,099,692, the disclosures of which are hereby incorporated by reference. Other literature describing supported inorganic crystalline molecular sieve layers includes U.S. Pat. No. 4,699,892; J. C. Jansen et al, Proceedings of 9th International Zeolite Conference 1992 (in which lateral and axial orientations of the crystals with respect to the support surface are described), J. Shi e al, Synthesis of Self-supporting Zeolite Films, 15th Annual Meeting of the British Zeolite Association, 1992, Poster Presentation (in which oriented Gmelinite crystal layers are described); and S. Feng et al, Nature, Apr. 28th 1994, p 834 (which discloses an oriented zeolite X analogue layer), the disclosures of which are hereby incorporated by reference.
Further examples of zeolite membranes which may be used in zeolite membrane units for the present invention are described in the following documents; International Application WO 94/25151, U.S. Ser. No. 267760 filed Jul. 8th 1994, PCT U.S. Pat. No. 95/08512, PCT U.S. Pat. No. 95/08514, PCT U.S. Pat. No. 95/08513, PCT EP96102704 and WO 94101209, the disclosures of which are hereby incorporated by reference. In our earlier International Application WO 94/25151 we have described a supported inorganic layer comprising optionally contiguous particles of a crystalline molecular sieve, the mean particle size being within the range of from 20 nm to 1 μm. The support is advantageously porous. When the pores of the support are covered to the extent that they are effectively closed, and the support is continuous, a molecular sieve membrane results; such membranes have the advantage that they may perform catalysis and separation simultaneously if desired. Preferred zeolite membranes are those which are prepared by the Inverted In-Situ-Crystallisation (I-ISC) process, or by using a GEL layer and a Low Alkaline synthesis solution using the Inverted In-Situ-Crystallisation process (GEL-LAI-ISC),or by using a Seeding Layer and a Low-Alkaline-synthesis solution using the Inverted In-Situ Crystallisation (S-LAI-ISC). These processes are described in U.S. Ser. No. 267760 filed Jul. 8th 1994, PCT U.S. Pat. No. 95/08512, PCT U.S. Pat. No. 95/08514, PCT U.S. Pat. No. 95/08513 and PCT EP95/02704. Zeolite compositions fabricated using the above described LAI-ISC, GEL-LAI-ISC, or S-LAI-ISC techniques can have dense zeolite layers in which the zeolite crystals are intergrown such that non-selective permeation pathways in these as-synthesised zeolite layers are virtually non-existent. The zeolite membranes described above may be incorporated into the zeolite membrane unit in the form of a module such as that described in WO 94/01209. It is envisaged that the zeolite membrane unit will contain at least one zeolite membrane which may or may not be catalytically active. If the membrane is not catalytically active for the desired process a suitable catalyst may be used in combination with the membrane. This catalyst may be located on the upstream side of the membrane or the downstream side of the membrane depending on the process and the nature and purpose of the catalyst. In one embodiment one or more membranes may be arranged with one or more catalysts to provide alternating membrane and catalyst regions in the zeolite membrane unit. In this arrangement the feedstream to the unit may for example pass through a membrane region with the retentate flowing to a catalyst containing region and then through a second membrane region to a second catalyst region. The exact number of membrane and catalyst regions will depend on the nature of the separations and catalyst processes desired. The separation and catalyst process may be substantially the same for each combination of catalyst and membrane or may be different.
It should be understood that two or more zeolite membrane units with or without isomerisation catalyst in close proximity to the zeolite membrane in each unit may be used in the processes of the present invention. Reference to zeolite membrane unit in this specification should also be taken to include embodiments where two or more zeolite membrane units may be used in sequence to each other with or without any further intervening processes or process units.
The zeolite membrane unit may be installed downstream of an existing xylenes isomerization reactor or installed as a replacement of an isomerization reactor in an existing paraxylene recovery process. The zeolite membrane unit may be added to an existing process solely for separation of paraxylene from xylenes, or for both isomerization and separation. The most preferred option is to have the zeolite membrane unit downstream of a xylenes isomerisation unit and for the zeolite membrane unit to comprise a zeolite membrane and an isomerisation catalyst so that it performs both isomerisation of xylenes, and selective separation of paraxylene; optionally it also catalyses conversion of ethylbenzene to xylenes or benzene. If the zeolite membrane unit catalyses conversion of ethylbenzene to xylenes or benzene then this may allow less conversion of ethylbenzene in the conventional isomerisation unit with less xylene losses due to the lower operating temperature which would be required in the conventional isomerisation unit.
It is preferred that the zeolite membrane unit is incorporated into a conventional xylene recovery loop such as that shown in FIG. 1 and discussed below. The xylene recovery process is referred to as a “loop” because xylenes not converted to paraxylene are recycled to the isomerization unit that is usually a part of the xylene recovery loop again and again until the xylenes are converted to paraxylene and removed from the loop via the paraxylene separation unit. In such a loop orthoxylene may also be a product which is removed from the loop in the xylene splitter if desired. Orthoxylene can sometimes be generated by the isomerisation unit if the feed to that unit has a less than equilibrium orthoxylene concentration.
As indicated above the fresh feed for the xylene recovery loop may come from a variety of sources in the petrochemical cycle. Fresh feed from, for example, a reformer, which is introduced to the xylene recovery loop is usually fractionated before introduction to the paraxylene separation unit to remove materials boiling below the boiling point of xylenes, and may optionally also be fractionated to remove at least part of the material boiling above the boiling point of xylenes. If lower boiling materials are not removed from the fresh feed, it is introduced to a detoluenizer tower (“DETOL”) which removes toluene and lighter materials by distillation. The feed is then introduced to either a xylene rerun tower or splitter. A xylene rerun tower removes C 9+ aromatics from the feed. A xylene splitter tower in addition removes at least part of the orthoxylene for subsequent recovery as orthoxylene product in an orthoxylene rerun tower. The fresh feed in a xylenes loop is combined with a recycle stream which comes from the xylene isomerisation unit or in the present invention from the zeolite membrane unit. The overhead stream from the xylene rerun tower or splitter is typically a mixture of compounds which includes 0 to 10 wt % non aromatics, 0 to 5 wt % toluene, 5 to 20 wt % ethylbenzene, 0 to 10 wt % C 8 naphthenes, and 70 to 95 wt % xylenes. The exact composition will depend on the fresh feed and the nature of the catalysts used in the isomerisation unit and in the zeolite membrane unit. It should be appreciated that the fresh feed to the xylenes recovery loop could be a combination of two or more feeds such as those discussed above. Thus it could be a combination of a feed from a naphtha reformer with that from a TATORAY™ or MSTDP™ unit.
It should be understood that in the present description when reference is made to a feed to, or material upstream of the membrane, in a zeolite membrane unit being at equilibrium in xylenes this means that it can be a mixture of xylenes which are at the typical respective concentrations for an equilibrium mixture of xylenes as known in the art. In the same context by near equilibrium is meant a composition comprising xylenes in which one or more of the xylenes present are at their none equilibrium concentration with respect to the other xylenes present and includes mixtures where one or more of the xylene isomers are present at a concentration which is greater than their equilibrium concentration. Ideally in such mixtures the paraxylene should be present at 50% or more, preferably 80% or more and most preferably at 90% or more of the paraxylene equilibrium concentration.
Other objects and features of the invention are described in the following detailed description wherein reference is made to the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows conventional xylenes loop comprising a paraxylene separation unit and an isomerisation unit.
FIG. 2 shows a xylene purification loop utilising a zeolite membrane unit.
FIG. 3 is a xylene purification loop utilising a zeolite membrane unit downstream of an isomerization unit.
FIG. 4 shows a xylene purification loop utilising an isomerization unit upstream of a zeolite membrane unit without isomerisation catalyst and used for separating a paraxylene enriched stream that is transferred to a paraxylene recovery unit.
FIG. 5 shows a xylene purification loop having an isomerization unit upstream from a zeolite membrane unit without isomerisation catalyst and used for separating a paraxylene enriched stream that is then transferred to a xylene splitter.
FIG. 6 shows a xylene purification loop which utilises an ethylbenzene membrane separation unit upstream of an ethylbenzene isomerisation unit which is upstream of an xylene isomerisation unit.
In FIG. 1 fresh feed containing xylenes is introduced to a xylene splitter 2 through fresh feed line 1 . A bottom stream 3 is withdrawn from the xylene splitter 2 containing materials having boiling points above xylenes and possibly containing orthoxylene. An overhead stream 4 is withdrawn from the xylene splitter containing xylenes and ethylbenzene. The overhead stream 4 is fed to paraxylene recovery unit 5 . Xylenes are separated in paraxylene recovery unit 5 to yield a paraxylene rich stream 6 and a paraxylene poor stream 7 . The paraxylene recovery unit normally uses fractional crystallisation and/or molecular sieve separation to separate paraxylene from other stream 4 components. The paraxylene poor stream 7 is then introduced to an isomerization (ISOM) unit 8 which contains an isomerization catalyst arranged and effective to promote isomerization of ortho and metaxylene to paraxylene and the conversion of ethylbenzenes to benzene and/or xylenes or other compounds. The isomerate 9 from the isomerisation unit 8 is then introduced to stabiliser 10 . Stabiliser 10 separates five carbon and lighter compounds from stream 9 through differences in boiling points. Five carbon and lighter compounds are withdrawn from stabiliser 10 through line 11 and six carbon and heavier compounds are withdrawn from stabiliser 10 through line 12 . The stream in line 12 is introduced to a DETOL unit 13 to remove toluene and lighter compounds through line 14 . Xylenes and heavier materials are withdrawn from DETOL unit 13 through line 15 and introduced to xylene splitter 2 . Normally fresh feed 2 and the xylenes withdrawn from the DETOL 13 through line 15 are passed through clay treaters which in order to simplify the figures are not shown in FIGS. 1 to 6 . As an alternative to the splitter 2 described in FIG. 1 a rerun tower may be used. It is to be understood that when reference is made to a splitter. In this specification that this reference also encompasses the use of a rerun tower in place of the splitter. For the purposes of this application the description “splitter” shall be used when substantial orthoxylene is removed in the bottoms and “rerun” shall be used when it is not.
There are a number of disadvantages associated with this conventional process arrangement for paraxylene recovery. The first is that this combination of process steps requires a significant recycle through the loop in order to remove the maximum possible amounts of paraxylene. This Is primarily due to the fact that the isomerisation unit and processes are only able to produce equilibrium or near equilibrium mixture of xylenes for the recycle in the isomerate. A typical concentration of paraxylene in the isomerate from such a unit is 22 wt %. Another problem is that in most isomerisation processes there are xylenes losses of up to 4% or higher. Thus with repeated recycles this loss of xylenes to undesirable products may be significant.
FIG. 2 shows a xylene purification loop according to the present invention. Fresh feed containing xylenes is introduced to a xylene splitter 21 through fresh feed line 20 . A bottom stream 22 is withdrawn from xylene splitter 21 containing materials having boiling points above xylenes and possibly containing orthoxylene. An overhead stream 23 is withdrawn from the xylene splitter containing xylenes and ethylbenzene. The overhead stream 23 is fed to paraxylene recovery unit 24 . Xylenes are separated in paraxylene recovery unit 24 to yield a paraxylene rich stream 25 and a paraxylene poor stream 26 . The paraxylene recovery unit normally uses fractional crystallisation and/or molecular sieve separation to separate paraxylene from other stream 23 components. The paraxylene poor stream 26 is then introduced to zeolite membrane unit 27 . Zeolite membrane unit 27 includes catalyst arranged and effective to promote isomerization of ortho- and metaxylene to paraxylene and the conversion of ethylbenzenes to benzene and/or xylenes or other compounds. The zeolite membrane also selectively permits permeation of paraxylene through the membrane relative to ortho- and metaxylene. A stream enriched in paraxylene is withdrawn from zeolite membrane unit 27 as permeate stream 28 . The remaining material In retentate stream 29 should ideally be at equilibrium or near equilibrium in xylenes. The permeate stream 28 and retentate stream 29 may be treated separately (not shown in FIG. 2) or combined to form combined feed 30 and introduced to stabiliser 31 . Stabiliser 31 separates five carbon and lighter compounds from stream 30 through differences in boiling points. Five carbon and lighter compounds are withdrawn from stabiliser 31 through line 32 and six carbon and heavier compounds are withdrawn from stabiliser 31 through line 33 . The stream in line 33 is introduced to a DETOL unit 34 to remove toluene and lighter compounds through line 35 . Xylenes and heavier materials are withdrawn from DETOL unit 34 through line 36 and introduced to xylene splitter 21 . In addition it is also possible to introduce all or some of the fresh feed directly into the zeolite membrane unit 27 as indicated at line 37 . This would have the advantage of further increasing the concentration of paraxylene in the paraxylene recovery unit feed, because a higher proportion of that feed would be derived from the zeolite membrane unit product rather than from the fresh feed having only an equilibrium or near equilibrium paraxylene concentration. However this approach requires a larger zeolite membrane unit, and may require a larger retentate stream to purge heavy aromatics brought in with the fresh feed, so there is an economic optimum for each application regarding how much, if any of the fresh feed to route directly to the zeolite membrane unit. For example in a retrofit situation where the paraxylene recovery unit capacity is limiting the plant production rate, it would likely be advantageous to route at least a portion of fresh feed to the zeolite membrane unit.
This embodiment of the present invention has a significant advantage over the conventional process as described in FIG. 1 . The zeolite membrane unit produces a permeate with a greater than equilibrium amount of paraxylene and a retentate which has an equilibrium or near equilibrium concentration. The combined products will have a higher paraxylene content than is possible with the conventional isomerisation unit, which is limited by equilibrium. When those streams are recycled to the paraxylene recovery unit via the xylene splitter the paraxylene concentration is increased there, increasing per pass paraxylene recovery and reducing recycle which is a problem with conventional processes. In this embodiment the zeolite membrane unit is required to relatively efficiently isomerise xylenes and convert ethylbenzene and requires a zeolite membrane which has selectivity for paraxylene and exhibits acceptable flux through the membrane. Such membranes may be prepared using the LAI-ISC, S-IAI-ISC and GEL-LAI-ISC methods described above.
The particularly preferred embodiment of the invention is shown in FIG. 3 . Fresh feed containing xylenes is introduced to xylene splitter through fresh feed line 40 . A bottom stream containing 9 carbon and heavier compounds and possibly containing orthoxylene is withdrawn from xylene splitter through line 42 . An overhead stream containing xylenes and ethylbenzene is withdrawn from xylene splitter 41 through line 43 and introduced to paraxylene recovery unit 44 . Paraxylene is recovered in a paraxylene rich stream 45 while ortho- and metaxylene are recovered in paraxylene poor stream 46 . The paraxylene poor stream 46 is introduced to an isomerization unit 47 which contains an isomerization catalyst arranged and effective to promote isomerization of ortho and metaxylene to paraxylene and the conversion of ethylbenzenes to benzene and/or xylenes or other compounds. Isomerised product is withdrawn through line 48 and introduced to zeolite membrane unit 49 containing zeolite membrane, catalyst that both isomerises ortho- and metaxylene to paraxylene and in which unit there is selective permeation of paraxylene through the zeolite membrane relative to ortho- and metaxylene. It should be noted that in this embodiment the catalyst may be incorporated into the membrane or the membrane itself may be catalytically active or rendered catalytically active or preferably it may be located on the upstream or inlet side of the membrane but in close proximity to the membrane. A stream enriched in paraxylene is withdrawn from zeolite membrane unit 50 through permeate stream 51 . The remaining material leaves in retentate stream 52 . Permeate stream 51 and retentate stream 52 may be treated differently (not shown in FIG. 3) or they may be combined in line 53 and introduced to stabiliser 54 . Stabiliser 54 separates five carbon and lighter compounds from stream 53 through differences in boiling points. Five carbon and lighter compounds are withdrawn from stabiliser 54 through line 55 and six carbon and heavier compounds are withdrawn from stabiliser 54 through line 56 . The stream in line 56 is introduced to a DETOL unit 57 to remove toluene and lighter compounds through line 58 . Xylenes and heavier materials are withdrawn from DETOL unit 57 through line 59 and introduced to xylene splitter 41 . In addition it is also possible for some or all of the fresh feed to be introduced to the isomerisation unit 47 or to the zeolite membrane unit 50 or to both as indicated at lines 60 and/or 61 . The reason for using such a split feed has already been discussed above In relation to FIG. 2 . Diverting fresh feed to either the isomerisation unit via line 60 or the zeolite membrane unit via line 61 would have similar benefits In terms of reduced xylene loop recycle. Using line 61 reduces flow through the isomerisation unit versus that required if line 60 is used. However it may still be advantageous to utilise line 60 , since then it would combine with the feed in line 46 and could use the same pumps and/or reactor preheating equipment. This may be particularly advantageous if the zeolite membrane unit and the lsomerisation unit operate under similar conditions where isomerisation unit effluent flows directly to the zeolite membrane unit without the need for heating, cooling and/or pressure change. In that situation, stream 53 would typically be cooled by transferring its heat to the isomerisation unit feed to provide at least part of the reactor preheat. Such feed/effluent heat exchange systems usually work at their most efficient when feed and effluent flow rates are approximately the same. The optimum distribution of fresh feed amongst lines 40 , 60 and 61 will vary depending on plant constraints and economic factors, and should be determined for each individual application. Conventional processes without zeolite membrane units have less flexibility in the routing of the fresh feed into the xylenes loop.
This particularly preferred embodiment not only has significant advantages over the prior art process of FIG. 1 but also has some significant advantages over that of FIG. 2 . The combination of the isomerisation unit and the zeolite membrane unit downstream of the isomerisation unit enables the beneficial attributes of both units to be combined for maximum paraxylene production. The embodiment in FIG. 2 requires a particularly efficient zeolite membrane unit, as the feed to this unit which is derived from the paraxylene recovery unit is significantly depleted in paraxylene. The paraxylene content may be as low as 1% or less with the balance being mainly ortho- and metaxylene, ethylbenzene and minor amounts of other materials. This means that the zeolite membrane unit must be able to quickly isomerise this feed to produce the required amount of paraxylene on the upstream side of the membrane which exact concentration of paraxylene depends on the membrane properties and in some case will need to be an equilibrium or near equilibrium mixture of xylenes to achieve maximum efficiency in the process. Furthermore the zeolite membrane unit must also efficiently convert ethylbenzene or this will build up in the xylenes loop. The use of an isomerisation unit in combination with the zeolite membrane unit in FIG. 3 overcomes these deficiencies with the embodiment of FIG. 2 . Firstly the isomerate from the isomerisation unit is already enriched In paraxylene and is typically at equilibrium or near equilibrium with respect to xylenes. This means that the zeolite membrane unit only has to maintain the Isomerate in or near this state to enable the membrane to work efficiently. Secondly because the isomerisation unit has the capability of ethylbenzene conversion, the ability of the zeolite membrane unit to destroy ethylbenzene, although desirable is not critical. Typically promoting xylenes equilibrium is easier than destroying ethylbenzene. The negative aspect of xylene losses which normally occur in the isomerisation unit is offset by the greatly reduced recycle needed when using the zeolite membrane unit in this embodiment. Also if the zeolite membrane unit does have at least some ethylbenzene conversion capability the Isomerisation unit does not have to do as much of this conversion. This would allow for the isomerisation unit to be operated under milder conditions and therefore result in less xylenes loss in the isomerisation unit. Also because there Is no need to for the feed to the zeolite membrane unit to be brought to equilibrium in this unit, as is required with some membranes when used in FIG. 2 embodiment, it may need significantly less catalyst and be significantly smaller in size compared to the zeolite membrane unit which is required for FIG. 2 . In the particularly preferred embodiment of FIG. 3 when a membrane of selectivity of 5 for paraxylene/(ortho- and metaxylene) and a flux of greater than 10 Kg/m 2 /day is used the predicted level of paraxylene in the feed leaving the zeolite membrane unit compared to the isomerate leaving the isomerisation unit is 55 wt % compared to 22 wt % (the equilibrium concentration if about 10 wt % nonxylenes are present). This provides for an overall increase in paraxylene production in the cycle of 50% or more. Suitable membranes for use in a zeolite membrane unit to provide such improved performance are described for example in U.S. Ser. No. 267760 filed Jul. 8th 1994, PCT U.S. Pat. No. 95/08512, PCT U.S. Pat. No. 95/08514, PCT U.S. Pat. No. 95/08513 and PCT EP95/02704.
FIG. 4 shows an embodiment of the invention using a zeolite membrane to separate paraxylene from a xylene stream. Fresh feed containing xylenes is introduced to xylene splitter 101 through fresh feed line 100 . Compounds boiling above xylenes and possibly including orthoxylene are withdrawn through bottom stream 102 and xylene and lighter boiling compounds are withdrawn as overhead stream 103 . Overhead stream 103 is Introduced to isomerization unit 104 through intermediate line 105 . The isomerization unit 104 converts ortho- and metaxylene to paraxylene and promotes the conversion of ethylbenzenes to benzene and/or xylenes or other compounds. Unconverted ortho- and metaxylene along with paraxylene are withdrawn from isomerization unit 104 through line 106 and introduced to stabiliser 107 . 5 carbon and lighter boiling compounds are withdrawn from stabiliser 107 through line 108 with the balance of material withdrawn through line 109 and introduced to DETOL unit 110 . Toluene and lighter boiling compounds are withdrawn from DETOL unit 110 through line 111 and xylenes are withdrawn through line 112 and introduced to zeolite membrane unit 113 . Zeolite membrane unit 113 comprises a zeolite membrane that is arranged and effective to permit selective permeation of paraxylene relative to ortho- and metaxylene Most paraxylene is withdrawn through permeate stream 114 and Introduced to paraxylene recovery unit 115 . Most ortho- and metaxylene are withdrawn from zeolite membrane unit 113 through retentate stream 116 and introduced to xylene splitter 101 . The paraxylene recovery unit 115 separates paraxylene from ortho- metaxylene. Paraxylene is withdrawn through paraxylene rich stream 117 and the balance of ortho- and metaxylene are withdrawn through paraxylene poor stream 118 . Paraxylene poor stream 118 is introduced to isomerization reactor 104 through line 105 . Alternatively all or part of overhead stream 103 may be directed to the zeolite membrane unit 113 via line 119 and 112 . The optimal routing of stream 103 depends on an economic balance amongst several parameters, namely isomerisation unit, per pass xylenes losses and ethylbenzene conversion and the zeolite membrane unit's relative selectivity between paraxylene and ethylbenzene. Routing steam 103 to zeolite membrane unit 113 has the advantage of avoiding whatever xylenes losses it would have incurred if it had been passed through the isomerisation unit 104 . However there is a potential risk in this instance that ethylbenzene will build up in the xylenes loop. For example if zeolite membrane unit 113 ensured that all the ethylbenzene was retained in the retentate 116 the ethylbenzene would be retained in the xylenes loop without removal or destruction and would build up indefinitely as additional ethylbenzene is brought into the loop in the fresh feed. However if the selectivity of the zeolite membrane in the unit was such that a substantial portion of the ethylbenzene permeated through the membrane and into stream 114 then that portion of the ethylbenzene would pass to the isomerisation unit 104 via lines 115 , 118 and 105 , where some of it would be converted thus limiting its build up in the xylenes loop. There is also the possibility of an intermediate case where a portion of the stream 103 passes to the zeolite membrane unit and the remainder flows to the isomerisation unit. In this case the flow to the isomerisation unit acts as a purge to prevent the build up of ethylbenzene to unacceptable levels if the amount permeating through the membrane in the membrane unit is insufficient. the optimal balance should be determined for each specific application and will depend on the membrane properties and the properties of the xylenes isomerisation catalyst amongst others.
Another embodiment of the invention is shown in FIG. 5 wherein xylenes are introduced to xylene splitter 201 through fresh feed line 200 . Compounds boiling above the boiling point of xylenes and possibly some of the orthoxylene are withdrawn from xylene splitter 201 through bottoms line 202 , xylenes and ethylbenzene are withdrawn through overhead stream 203 and introduced to paraxylene recovery unit 204 Paraxylene is withdrawn through paraxylene rich stream 205 and ortho- and metaxylene are withdrawn through paraxylene poor stream 206 . Paraxylene poor stream 206 is introduced to an isomerization unit 207 through line 208 . Isomerization unit 207 isomerises ortho- and metaxylene to paraxylene and promotes the conversion of ethylbenzene to benzene and/or xylenes or other compounds. The isomerate is withdrawn through line 209 . The isomerate mixture which contains a near equilibrium mixture of ortho-, meta- and paraxylene is introduced to stabiliser 210 through line 209 . 5 carbon and lighter compounds are withdrawn through line 211 and heavier boiling compounds are withdrawn through line 212 and introduced to DETOL unit 213 . Toluene and lighter boiling compounds are withdrawn through line 214 , xylenes and heavier materials are withdrawn from the DETOL unit 213 through line 215 . Xylenes and heavier materials in line 215 are introduced to zeolite membrane unit 216 which comprises a zeolite membrane arranged and effective to permit selective permeation of paraxylene there through. Most paraxylene is withdrawn through line 217 and introduced to xylene splitter 201 . Ortho- and metaxylene are withdrawn as retentate stream 218 and reintroduced to isomerization unit 207 through line 208 . However it will likely be necessary to purge a portion of this stream to xylene splitter 201 via line 219 to avoid an excessive build up of C9+ aromatics as they will tend to stay in the retentate and not be removed in the stabiliser or DETOL units.
A further embodiment of the invention is shown in FIG. 6 . In this embodiment the zeolite membrane unit has as its primary function the separation of ethylbenzene from a paraxylene depleted stream so that this may be passed into an ethylbenzene isomerisation unit. Thus a feed comprising xylenes and ethylbenzene 300 is passed to a xylene re-run fractionation sequence 312 and into a paraxylene recovery unit 301 via line 315 . Paraxylene is withdrawn through paraxylene rich stream 302 and ortho- and metaxylene and ethylbenzene are withdrawn through paraxylene poor stream 303 . Paraxylene poor stream 303 is introduced to a zeolite membrane unit 304 comprising a zeolite membrane which permits selective permeation of ethylbenzene and possibly paraxylene through the zeolite membrane relative to ortho- and metaxylene. Most of the ethylbenzene and possibly most of the paraxylene is withdrawn from the zeolite membrane unit 304 through permeate stream 305 and most of the ortho- and metaxylene are withdrawn through retentate stream 306 . Permeate stream 305 passes into an ethylbenzene isomerisation unit 307 . Ethylbenzene isomerization unit 307 isomerises ethylbenzene to xylenes The ethylbenzene isomerate is withdrawn through line 308 . The retentate 306 and ethylbenzene isomerate 308 are combined to provide a unified feed 309 to the isomerisation unit 310 which may be a liquid phase xylenes isomerisation unit operating at 200° C. The xylenes isomerate passes from the isomerisation unit 310 through line 311 to a xylene re-run fractionation sequence 312 which produces a heavy stream 313 , a lights stream 314 and a xylenes recycle 315 . The lights stream may be further treated to a fractionation process to produce a C 8 naphthene recycle 316 to the ethylbenzene isomerisation unit 307 (shown as dotted lines in the figure). A possible addition to the process described in FIG. 6 is the inclusion of a zeolite membrane unit after the isomerisation unit 310 but before the xylene re-run fractionation sequence 312 . This additional zeolite membrane unit would further enrich the stream 311 in paraxylene.
In this embodiment for a given membrane the predicted recovery of ethylbenzene on the permeate side of the membrane is 44 wt % compared to a normal ethylbenzene concentration of 6 to 7 wt %. The ethylbenzene conversion across the ethylbenzene isomerisation unit is 85% which compares favourably with a conventional process where the per pass conversion is 42%. Because a much smaller portion of the xylene loop is subjected to the severe conditions of the ethylbenzene isomerisation unit there are lower overall xylene losses. Also because the xylenes isomerisation unit conditions are less severe than in a combined ethylbenzene/xylenes isomerisation unit the losses of xylenes in this unit are significantly lower; 1% compared to 3 to 4%. This results in an overall yield for paraxylene for this embodiment of 94.5% compared to 84.5% for the conventional xylene loop without zeolite membrane unit. An additional advantage of this embodiment is that the amount of hydrogen circulation is dramatically reduced as the ethylbenzene conversion is in a separate reactor and hydrogen is not required for the xylenes isomerisation unit. This may result in a significant savings on the cost of operating a paraxylene recovery process according to this embodiment compared to the conventional xylenes loop.
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This invention relates to a process and a chemical plant for the production primarily of paraxylene. In particular the process and chemical plant utilise zeolite membranes for enhanced paraxylene production.
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BACKGROUND OF THE INVENTION
[0001] The invention relates to a method for analyzing samples of metal melts, wherein a sample is taken from a metal melt using a sampler having a sample chamber and which is constructed as an immersion lance. Further, the invention relates to a device for taking samples in metal melts, using a sampler having a sample chamber and which is constructed as an immersion lance, wherein the device may be particularly suitable for carrying out the method according to the invention.
[0002] In molten metal processes, particularly in the manufacture of cast iron or steel, regular analyses of the melt are necessary. For the economy of the process it is necessary thereby that the analyses can be carried out in the shortest possible time, in order to be able to regulate process guidance accordingly in a timely manner.
[0003] Sample analysis methods are known, for example, from European Patent EP 563 447 B1. Using the technique described there, the nitrogen content in metal melts can be determined. Similar devices and methods are known from European Patent EP 307 430 B1. Using the device described there, in particular, the hydrogen content in metal melts can be analyzed. International Patent Application Publication WO 2005/059527 A1 discloses analytical methods and devices for the metal melt, which work with single-use spectrometers. From U.S. Pat. No. 4,342,633 immersion probes for single use are known, with which temperature and oxygen content of metal melts can be determined. In Japanese patent application publication (Kokai) JP 3-071057 A a sampling device for steel melts is described, in which the sample is taken with the aid of an immersion lance, wherein the sample during withdrawal of the lance from the metal melt is brought into a hermetically sealed chamber. From German published patent application DE 33 44 944 A1 it is known to take samples, to transport them to analytical laboratories and to conduct the analysis there. Furthermore, a spectroscopic investigation of metallurgical immersion probes is known from German published patent application DE 32 00 010 A1. Here, in particular, the sample is maintained under vacuum or inert gas atmosphere, in order to prevent oxidation of the hot sample.
BRIEF SUMMARY OF THE INVENTION
[0004] An object of the present invention is to shorten further the time between sample collection and analysis and thereby to avoid adulteration of the sample.
[0005] The object is achieved by the method according to the invention for analyzing samples of metal melts, particularly of cast iron or steel melts, in which a sample is taken from a metal melt using a sampler having a sample chamber and which is constructed as an immersion lance. The method is characterized in that the sample from the sampler is transported through a transport conduit to the sphere of action of an analytical device and in that the sample is analyzed there by the analytical device. In particular, the analytical device may be a spectrometer.
[0006] Here, the sample is moved directly from the immersion lance into the transport conduit (directly following the immersion lance) and from there to the analytical device, so that first a rapid transport is guaranteed, and second, external influences on the sample are largely excluded. The transport conduit may be constructed as a pneumatic tube line. Preferably, the sample can be divided into several (for example 2 to 4) solid parts, wherein the division may already take place in the sampler and parts of the sample may be transported to the sphere of action of the analytical device.
[0007] Preferably, the sample may also be connected to a portion of the sample chamber which is detachable from the complete sample chamber and, together with this portion, may be transported to the sphere of action of the analytical device. It may also be advantageous that the sample together with the sample chamber is transported through the transport conduit to the sphere of action of the analytical device, where a portion of the sample chamber is removed and the thus-exposed surface area of the sample is analyzed.
[0008] In particular, it may be suitable that during the transport through the transport conduit the sample is exposed to vacuum or inert gas. It may also be advantageous that vacuum or inert gas is generated prior to sampling, at least in the sample chamber. It may also be suitable that vacuum or inert gas is generated at least in the sample chamber and maintained until the sample is cooled to a temperature of ≦400° C. The transport of the sample may be carried out preferably by compressed gas. A transport under vacuum (suction of the sample) is also possible. As the compressed gas, in particular, an inert gas (for example argon) may be used, which optionally may be replaced with compressed air, when the sample has cooled to a temperature of ≦400° C.
[0009] The device according to the invention for taking samples in metal melts, using a sampler having a sample chamber and which is constructed as an immersion lance, is characterized in that the sample chamber is arranged in a cartridge, such that the sampler is connected to a first end of a transport conduit of the cartridge containing the sample or the sample-containing sample chamber, and in that a second end of the transport conduit is connected to an analytical device. The outer contour of the cartridge is adapted to the inner contour of the immersion lance and to the immediately following transport conduit and serves for the transport of the sample chamber. The cartridge may be integrated into the sample chamber, for example, when the outer contour of the sample chamber is adapted to the inner contour of the immersion lance and transport conduit. In particular, the analytical device may be a spectrometer.
[0010] Expediently, the sample chamber or a portion thereof is detachable from the sampler and is transportable through the transport conduit. Furthermore, it is advantageous that the transport conduit have a compressed gas connection and/or a vacuum connection. Furthermore, it is expedient that the sample chamber and/or the cartridge have a vacuum connection or an inert gas connection. Using the device according to the invention, a quick sampling and transporting of the sample to an analytical device is possible, without the sample being exposed to damaging environmental impacts in between.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0011] The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:
[0012] FIG. 1 is a schematic, side, sectional representation of a sampling and measuring arrangement according to an embodiment of the invention;
[0013] FIG. 2 is a similar representation of a sampling and measuring arrangement according to another embodiment of the invention;
[0014] FIG. 3 is a partial, schematic, sectional representation showing a sampler and the transport of a sample according to an embodiment of the invention; and
[0015] FIG. 4 is a schematic, side, sectional representation of another embodiment of a sampler according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] In FIG. 1 a melt container 1 for molten steel is represented, in which an immersion lance 2 , serving as a sampler, is immersed. A sample chamber 3 is arranged at the immersion end of the immersion lance. The sample chamber 3 is a so-called lollipop sample chamber, thus a flat sample chamber having an elliptical cross section, which has an inlet 4 at its immersion end. The sample chamber 3 is fixed in a cartridge 5 . Using this cartridge 5 , the sample chamber 3 is transported by the immersion lance 2 and the directly following transport conduit 6 to a spectrometer 7 , which serves as an analytical device.
[0017] In FIG. 2 a very similar arrangement is represented, wherein the spectrometer 7 is shown with its spark stand 8 . In the arrangements shown in the figures, the sample chamber 3 is opened after its arrival at the spectrometer 7 . Here, the inert gas introduced into the sample chamber 3 evaporates before immersion into the molten steel.
[0018] The inert gas supply to sample chamber 3 is carried out in a known manner, as shown for example in DE 32 00 010 A1. Using inert gas, which alternatively may be replaced by vacuum, prevents the liquid steel sample or the cooled steel sample from oxidizing at high temperatures.
[0019] Upon reaching the spectrometer 7 , the sample has a temperature of well below 400° C., so that inert gas or vacuum to protect the sample is no longer needed. Sample chamber 3 opens upon arrival at spectrometer 7 . The opening can occur, among other ways, by the kinetic force of the sample, but also mechanically by opening the two half shells of the sample chamber 3 by a spring or by a manipulator, for example by a cutting disk or even by action of compressed air. By detaching at least one of the two half shells of the sample chamber 3 , a surface of the sample becomes accessible for analysis. Since the sample collection and the transportation of the sample is carried out under inert gas (for example argon), oxidation is prevented, so that the sample for analysis does not additionally have to be freed of oxidation in an appropriate way, hence sample preparation prior to analysis is no longer necessary.
[0020] Such a sample feed to an analytical device takes place very quickly and directly, without intermediate stages during which the sample has to be transported on a different transport path. By connection of the transport conduit 6 with the immersion lance 2 and the analytical device, the use of an elaborate analytical device in the immediate vicinity of the melt is redundant. In practice, the analysis can be carried out in less than two minutes, because the transport is very fast and begins immediately after sampling. In addition, an automatic sample identification is possible, by which the process analysis can be improved. The analytical device may be installed in a mobile laboratory or in an otherwise fixed laboratory, for example in a central laboratory. In steel mills such laboratories are sufficiently available.
[0021] In the Figures the sample chamber 3 is shown as a flat sample chamber, which is fixed in a cartridge 5 . The immersion lance 2 has a round internal cross-section, which connects seamlessly to the likewise round and equal size internal cross-section of the transport conduit 6 , so that the cartridge 5 with its likewise round exterior cross-section can be transported without any problems.
[0022] Instead of a flat sample chamber, it is also conceivable that a sample chamber having a round cross section (perpendicular to the direction of transport) is used. In this case, the cartridge is essentially the same as the outer shell of the sample chamber 3 , so that the cartridge is integrated directly into the sample chamber 3 .
[0023] The transport of the sample chamber 3 to the analytical device, which, for example, comprises the above-mentioned spectrometer 7 , takes place by compressed air. This is shown in FIG. 3 in two phases of motion of the sample chamber 3 . At its end, not shown in FIG. 3 , the immersion lance 2 transitions seamlessly into the transport conduit 6 . Within the wall of the immersion lance 2 and optionally the transport conduit 6 , compressed gas lines are arranged, with whose aid a gas may be pressed with sufficiently high pressure against the immersion end of the cartridge 5 , so that it is transported in the direction of the analytical device.
[0024] The cross section of the cartridge 5 that remains free can suitably be closed using a disc made of a refractory material, for example at the end of the cartridge 5 away from the immersion end, so that the gas pressure effectively causes the transport of the sample chamber 3 . In the immersion position of the sample chamber 3 , in FIG. 3 the protective caps 10 arranged at the inlet opening 4 of the sample chamber 3 are shown, which caps melt or dissolve when immersed in the steel melt, so that the steel melt may flow into the sample chamber 3 .
[0025] FIG. 4 shows another possible embodiment of the invention. The lower part of FIG. 4 shows the immersion lance 2 , and the upper part of FIG. 4 shows the transport conduit 6 leading into the analytical device. The sample chamber 3 ′ is constructed as a flat sample chamber, whose larger extension runs perpendicular to the immersion direction. At its end facing away from the immersion end, the sample chamber 3 ′ is equipped with a removable lid 11 , which is removed after arrival of the sample chamber 3 ′ at the spectrometer 7 . The spectrometer 7 contains a spark stand, with whose aid the sample will be analyzed at its freely accessible surface after removal of the lid 11 .
[0026] The analytical device contains a gas inlet 12 . A gas conduit 13 is provided for the introduction of the inert gas—compressed gas in the immersion lance 2 at its immersion end. There, a gas supply line 14 for the introduction of inert gas into the sample chamber is also arranged. The sample chamber itself is filled through an inlet pipe 15 made of quartz glass.
[0027] The individual parts of the device are constructed of materials conventionally used in samplers.
[0028] It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.
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A method is provided for analyzing samples of metal melts, wherein a sample is taken from a metal melt using a sampler having a sample chamber and which is constructed as an immersion lance. The method includes transporting the sample from the sampler through a transport conduit to the sphere of action of an analytical device, and analyzing the sample there using the analytical device.
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RELATED APPLICATIONS
This application claims priority of provisional U.S. application No. 60/463,257, filed Apr. 15, 2003, the contents of which are incorporated by reference herein in their entirety.
FIELD OF THE INVENTION
The field of the invention is pharmaceutical compositions and methods, and especially as they relate to compositions and methods for the treatment of viral diseases.
BACKGROUND OF THE INVENTION
Hepatitis C virus (HCV) infection presents a significant worldwide health problem that affects approximately 170 million people, with about 30,000 new cases in the United States each year. HCV is not easily cleared by the host's immunological defenses, and as many as 85% of the people infected with HCV become chronically infected, often resulting in chronic liver disease, including cirrhosis and hepatocellular carcinoma (Hoofnagle, J. H. 1997 , Hepatology 26: 15S–20S). Chronic hepatitis C is the leading cause of chronic liver disease, the leading indication for liver transplantation in the United States, and The Centers for Disease Control and Prevention estimates that chronic hepatitis C virus infection is responsible for approximately 10,000 to 12,000 deaths in the United States annually. This number is expected to triple in the next 10 to 20 years without effective intervention.
HCV belongs to the family Flaviviridae , genus hepacivirus, which includes three genera of small, enveloped positive-strand RNA viruses. The 9.6 kb genome of HCV consists of a long open reading frame (ORF) flanked by 5′ and 3′ non-translated regions (NTR's). The polyprotein is cleaved both co- and post-translationally by cellular and viral proteases into at least four structural and six nonstructural (NS) proteins. One of these nonstructural proteins is NS5B, the RNA-dependent RNA polymerase, which plays a central role in viral RNA replication of HCV as well as other viruses of the Flaviviridae family.
Unfortunately, the development of effective vaccines for prophylaxis and/or treatment of HCV has been impeded by various virus-specific difficulties, and especially immune evasion. Thus, current treatment of HCV predominantly employs therapeutics that reduce serum HCV levels via monotherapy with (pegylated) interferon-alpha or in combination therapy with the nucleoside analogue ribavirin. While monotherapy results in only 10% sustained virological response (SVS), combination therapy has been shown to improve sustained responses to 54–56% (Michielsen P. et al., 2002 , Acta Gastroenterol Belg 65(2), 90–94). Clearly, effective antiviral therapies that prevent and alleviate complications suffered by millions of individuals chronically infected with HCV are needed.
Quinoxalines are a well-known class of compounds (O. Hinsberg, J. Liebigs Ann. Chem . 237, 327 (1986)), and selected quinoxaline derivatives have been described for use in various therapeutic applications. For example, selected 4-N-aroyl-, arylacyl- and arylsulfonyl-3,4-dihydroquinoxalin-2(1H)-ones were described as anti-inflammatory agents in a series of patent applications by Sumitomo Chem. Co. Ltd. (see e.g., JP 17,137/69, JP 17,136/69, JP 7,008/422, BE 706,623), and 3,4-Dihydroquinoxalin-2(1H)-one-3-carboxamides were described as anti-inflammatory compounds in U.S. Pat. No. 3,654,275. In another example, selected pyridinyl-alkyltetrahydropyrazino[1,2-a]quinoxalinone derivatives were described in U.S. Pat. Nos. 4,203,987 and 4,032,639 as antihypertensive and antisecretory reagents. Furthermore, 4-N-benzenesulfonyl-3,4-dihydroquinoxalin-2(1H)-one-1-alkyl carboxylic acids were reported as aldose reductase inhibitors as described in European Patent Application EP 266,102, and selected quinoxalines were described in U.S. Pat. No. 6,369,057 as therapeutic agents against HIV. However, none of the known quinoxaline derivatives have been demonstrated to exhibit activity against RNA-dependent RNA polymerases, and especially the RNA polymerase NS5B of HCV. The absence of RNA-dependent RNA polymerases in mammals, and the fact that this enzyme appears to be essential to viral replication, would suggest that the NS5B polymerase is an ideal target for anti-HCV therapeutics.
Thus, while numerous therapeutic compounds for treatment of HCV infections are known in the art, all or almost all of them suffer from various disadvantages. Therefore, there is still a need to provide compositions and methods for effective treatment of viral infections, and especially for the effective treatment of HCV infections.
DETAILED DESCRIPTION
The present invention is directed to various classes of quinoxaline derivatives, including their prodrugs and metabolites, and methods of use in the inhibition of viral polymerases, and especially viral RNA-dependent RNA polymerases. The inventors further contemplate numerous compositions and alternative uses for the compounds according to the inventive subject matter, especially as they relate to compounds, compositions and methods for treatment of diseases in humans.
The term “alkyl” as used herein refers to unsaturated hydrocarbon groups in a straight, branched, or cyclic configuration (also referred to as cycloalkyl, see below), and particularly contemplated alkyl groups include lower alkyl groups (i.e., those having six or fewer carbon atoms). Exemplary alkyl groups are methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tertiary butyl, pentyl, isopentyl, hexyl, isohexyl, etc. The term “alkenyl” as used herein refers to an alkyl as defined above and having at least one double bond. Thus, particularly contemplated alkenyl groups include straight, branched, or cyclic alkenyl groups having two to six carbon atoms (e.g., ethenyl, propenyl, butenyl, pentenyl, etc.). Similarly, the term “alkynyl” as used herein refers to an alkyl or alkenyl as defined above and having at least one triple bond. Especially contemplated alkynyls include straight, branched, or cyclic alkynes having two to six total carbon atoms (e.g., ethynyl, propynyl, butynyl, pentynyl, etc.).
The term “cycloalkyl” as used herein refers to a cyclic alkane (i.e., in which a chain of carbon atoms of a hydrocarbon forms a ring), preferably including three to eight carbon atoms. Thus, exemplary cycloalkanes include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. It should further be appreciated that cycloalkyls may also include a double bond. The term “aryl” as used herein refers to an aromatic carbon atom-containing ring. Thus, contemplated aryl groups include but are not limited to phenyl, naphthyl, and the like. Further contemplated aryl groups may be fused to another aryl group, and are thus termed “fused aryl”.
As also used herein, the terms “heterocycle”, “cycloheteroalkyl”, and “heterocyclic base” are used interchangeably herein and refer to any compound in which a plurality of atoms form a ring via a plurality of covalent bonds, wherein the ring includes at least one atom other than a carbon atom. Particularly contemplated heterocyclic bases include 5- and 6-membered rings with nitrogen, sulfur, or oxygen as the non-carbon atom (e.g., imidazole, pyrrole, triazole, dihydropyrimidine, indole, pyridine, thiazole, tetrazole etc.). Further contemplated heterocycles may be fused (i.e., covalently bound) to another ring or heterocycle, and are thus termed “fused heterocycle” or “fused heterocyclic base” as used herein.
The term “alkoxy” as used herein refers to straight or branched chain alkoxides, wherein the hydrocarbon portion may have any number of carbon atoms (and may further include a double or triple bond). For example, suitable alkoxy groups include methoxy (MeO—), ethoxy, isopropoxy, etc. Similarly, the term “alkylthio” refers to straight or branched chain alkylsulfides, wherein the hydrocarbon portion may have any number of carbon atoms (and may further include a double or triple bond). For example, contemplated alkylthio groups include methylthio (MeS—), ethylthio, isopropylthio, etc. Likewise, the term “alkylamino” refers to straight or branched alkylamines, wherein the hydrocarbon portion may have any number of carbon atoms (and may further include a double or triple bond). Furthermore, the hydrogen of the alkylamino may be substituted with another alkyl group. Therefore, exemplary alkylamino groups include methylamino, dimethylamino, ethylamino, diethylamino, isopropylamino, t-butylamino, etc. Furthermore, the term “alkylsulfonyl” refers to straight or branched chain alkylsulfones, wherein the hydrocarbon portion may have any number of carbon atoms (and may further include a double or triple bond). For example, contemplated alkylsulfonyl groups include methylsulfonyl (MeS(O) 2 —), ethylsulfonyl, isopropylsulfonyl, etc.
The term “alkyloxycarbonyl” as used herein refers to straight or branched chain esters of a carboxylic acid (derivative) and may have any number of carbon atoms (and may still further include a double or triple bond). Exemplary alkyloxycarbonyl groups include methyloxycarbonyl (MeOC(O)—), ethyloxycarbonyl, and butyloxycarbonyl.
The term “halogen” as used herein refers to fluorine, chlorine, bromine and iodine.
It should further be recognized that all of the above-defined groups might further be substituted with one or more substituents, which may in turn be substituted as well. For example, where a hydrogen atom in an alkyl is substituted with an amino group, one or both hydrogen atoms in the amino group may be substituted with another group (e.g., alky or alkenyl).
The term “substituted” as used herein refers to a replacement of an atom or chemical group (e.g., H, NH 2 , or OH) with a fimctional group, and particularly contemplated functional groups include nucleophilic groups (e.g., —NH 2 , —OH, —SH, —NC, etc.), electrophilic groups (e.g., C(O)OR, C(X)OH, etc.), polar groups (e.g., —OH), non-polar groups (e.g., aryl, alkyl, alkenyl, alkynyl, etc.), ionic groups (e.g., —NH 3 + ), halogens (e.g., —F, —Cl), NHCOR, NHCONH 2 , NHCSNH 2 , OCH 2 COOH, OCH 2 CONH 2 , OCH 2 CONHR, OC(Me) 2 COOH, OC(Me) 2 CONH 2 , NHCH 2 COOH, NHCH 2 CONH 2 , NHSO 2 R, NHSO 2 CF 3 , OCH 2 -heterocycles, PO 3 H, SO 3 H, (CH 2 ) 1-3 COOH, CH═CHCOOH, O(CH 2 ) 1-4 COOH, NHCOCH 2 CH(OH)COOH, CH(COOH) 2 , CH(PO 3 H) 2 , OCH 2 CH 2 CH 2 COOH, NHCHO, and all chemically reasonable combinations thereof. Moreover, the term “substituted” also includes multiple degrees of substitution, and where multiple substituents are disclosed or claimed, one or more of the disclosed or claimed substituent moieties can independently substitute the substituted compound.
Thus, the term “functional group” and “substituent” are used interchangeably herein and refer to groups including nucleophilic groups (e.g., —NH 2 , —OH, —SH, —NC, —CN etc.), electrophilic groups (e.g., C(O)OR, C(X)OH, C(Halogen)OR, etc.), polar groups (e.g., —OH), non-polar groups (e.g., aryl, alkyl, alkenyl, alkynyl, etc.), ionic groups (e.g., —NH 3 + ), and halogens, as well as NHCOR, NHCONH 2 , NHCSNH 2 , OCH 2 COOH, OCH 2 CONH 2 , OCH 2 CONHR, OC(Me) 2 COOH, OC(Me) 2 CONH 2 , NHCH 2 COOH, NHCH 2 CONH 2 , NHSO 2 R, NHSO 2 CF 3 , OCH 2 -heterocycles, PO 3 H, SO 3 H, (CH 2 ) 1-3 COOH, CH═CHCOOH, O(CH 2 ) 1-4 COOH, NHCOCH 2 CH(OH)COOH, CH(COOH) 2 , CH(PO 3 H) 2 , OCH 2 CH 2 CH 2 COOH, NHCHO etc.
COMPOUNDS OF THE INVENTION
In one aspect of the inventive subject matter, contemplated quinoxaline derivatives will generally have a structure according to Formula 1:
wherein Z is NH or O; X is selected from OH, NH 2 , OR, NHR, NRR, SH, or SR; R 1 and R 2 are independently selected from H, substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, fused aryl, heterocycle or fused heterocycle, and R 1 and R 2 together with the carbon atoms to which they are attached may form a 5- or 6-membered ring; R 3 is substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, fused aryl, heterocycle or fused heterocycle; and wherein R and R 4 are independently H, substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, fused aryl, heterocycle or fused heterocycle.
In another aspect of the inventive subject matter, contemplated quinoxaline derivatives will generally have a structure according to Formula 2:
wherein Z is NH or O; X is CONH 2 , COOR, CONHR, CONRR, COR, heterocycle, R, SO 3 H, PO 3 H, CH(COOH) 2 , CH(PO 3 H) 2 , tetrazole, or triazole; R 1 and R 2 are independently selected from H, substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, fused aryl, heterocycle or fused heterocycle, and R 1 and R 2 together with the carbon atoms to which they are attached may form a 5- or 6-membered ring; R 3 is substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, fused aryl, heterocycle or fused heterocycle; and wherein R and R 4 are independently H, substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, fused aryl, heterocycle or fused heterocycle.
In a further aspect of the inventive subject matter, contemplated quinoxaline derivatives will generally have a structure according to Formula 3:
wherein X is NH 2 , OR, NHR, NRR, heterocycle, or R; R 1 and R 2 are independently selected from H, substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, fused aryl, heterocycle or fused heterocycle, and R 1 and R 2 together with the carbon atoms to which they are attached may form a 5- or 6-membered ring; R 3 is substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, fused aryl, heterocycle or fused heterocycle; and wherein R and R4 are independently H, substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, fused aryl, heterocycle or fused heterocycle.
In yet another aspect of the inventive subject matter, contemplated quinoxaline derivatives will generally have a structure according to Formula 4 or Formula 5:
wherein U is selected from CH, CR, COR, CSR, CNHR, CNRR, CNHCH 2 COOH, CNHCH 2 COOR, CNHCH 2 CONH 2 , and N; V is N, CH, or CR, or null; Z is NH or O; X is COOH, COOR, CONH 2 , CONHR, CONRR, NH 2 , OR, NHR, NRR, SR, or heterocycle; R 1 and R 2 are independently selected from H. substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, fused aryl, heterocycle or fused heterocycle, and R 1 and R 2 together with the carbon atoms to which they are attached may form a 5- or 6-membered ring; R′, R″, R′″ are independently H, OH, OR, SH, SR, NH 2 , NHR, NRR, NO 2 , Cl, F, Br, I, CN, N 3 , COR, COOH, COOR, CONH 2 , CONHR, CONRR, C(═NH)NHR, CH 2 CH 2 COOH, OCH 2 COOH, NHCONH 2 , NHCHO, NHSO 2 R, NHCOR, substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, fused aryl, heterocycle or fused heterocycle; and wherein R and R 4 are independently H, substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, fused aryl, heterocycle or fused heterocycle.
In a still further aspect of the inventive subject matter, contemplated quinoxaline derivatives will generally have a structure according to Formula 6:
wherein U is selected from CH, CR, COR, CSR, CNHR, CNRR, CNHCH 2 COOH, CNHCH 2 COOR, CNHCH 2 CONH 2 , and N; D is O, S, NH, NR, or CRR; R 5 is H, OH, SH, OR, SR, NH 2 , NHR, NRR, O-aryl, or NH-aryl; R 2 is H, substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, fused aryl, heterocycle or fused heterocycle; R 6 is H, CH 2 CH 2 COOH, CH 2 COOH, substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, fused aryl, heterocycle or fused heterocycle; and wherein R and R 4 are independently H, substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, fused aryl, heterocycle or fused heterocycle.
In another aspect of the inventive subject matter, contemplated quinoxaline derivatives will generally have a structure according to Formula 7:
wherein Z is NH or O; R 1 and R 2 are independently selected from H, substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, fused aryl, heterocycle or fused heterocycle, and R 1 and R 2 together with the carbon atoms to which they are attached may form a 5- or 6-membered ring; R 3 is substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, fused aryl, heterocycle, or fused heterocycle, wherein R may further optionally include a COOH group that is covalently coupled to R via zero to three atoms; R 5 and R 6 are either H, alkyl, or together are connected via an additional 1–4 atoms to form a substituted or unsubstituted cyclic group containing 3–6 atoms; and wherein R and R 4 are H, substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, fused aryl, heterocycle or fused heterocycle.
It should still further be appreciated that where compounds of the invention comprise one or more stereocenters, all diastereomeric and/or enantiomeric forms and all reasonable combinations thereof are expressly contemplated to be within the scope of the invention. For example, although compounds 1 and 3–5 include an asymmetric center that is depicted in only one enantiomeric form, the corresponding opposite enantiomeric forms are also expressly contemplated herein. Similarly, it should be understood that where only one stereoelectronic isomer is depicted, the corresponding other stereoisomeric structures are also contemplated (e.g., keto/enol tautomeric forms, or imine/ketimine tautomeric forms).
Moreover, it should be recognized that prodrugs and metabolites of the compounds according to Formulae 1–9 are contemplated. There are numerous prodrug modifications of pharmacologically active molecules known in the art, and all of such modifications are considered suitable for use herein. However, especially preferred prodrugs include those that deliver compounds of the invention to a target cell (e.g., hepatocyte infected with HCV) or target organ (e.g., liver infected with HCV), wherein the prodrug form may be converted within a cell, organ, or other body compartment in an enzymatic or non-enzymatic manner. Further preferred prodrugs particularly include those in which the prodrug form is less active as compared to the corresponding non-prodrug form. Thus, specifically preferred compounds may include a moiety that increases uptake of the prodrug into a cell, or that increases preferential retention of the compound (which may or may not be in prodrug form) in a cell. Alternatively, the compounds of the invention may be formulated to increase target specificity of the compound (e.g., organ specific liposomes).
With respect to the metabolite, it should be recognized that metabolites of the compounds of the invention might be formed by one or more enzymatic reactions (e.g., via hydrolysis, oxidation, reduction, lyase, or ligase reaction, or even via a polymerase action), or via non-enzymatic reactions (e.g., acid hydrolysis, reduction). For example, a hydrolase or lyase may cleave a portion of compounds of the invention to a more active form. On the other hand, reactions of hydroxylases, ligases, or other enzymes that add chemical groups to the compounds according to the inventive subject matter (to render the compounds more active) are also contemplated herein. Thus, it should be recognized that all metabolites that have a desirable therapeutic effect, and especially an antiviral effect are deemed suitable.
The invention also provides pharmaceutical compositions, comprising a compound of the invention as described herein in, or a pharmaceutically acceptable salt thereof, in combination with a pharmaceutically acceptable carrier. Pharmaceutically acceptable salts are those salts containing one or more non-toxic counterions, including but not limited to sodium, postassium, calcium, and magnesium salts, as well as chloride, bromide, sulfate, acetate, and methanesulfonate salts. Methods of preparing salt forms of pharmaceutical agents are well-known to those of skill in the art.
The invention further provides methods of treating viral diseases, comprising administering a pharmaceutical composition of the invention to a subject in need of such treatment. It is generally contemplated that compounds of the invention will advantageously inhibit a viral polymerase, and especially the RNA dependent RNA polymerase of HCV. Accordingly, such compounds of the invention are expected to be effective in the treatment of HIV-infected individuals. Yet further contemplated uses of the compounds of the invention include treatment of inflammatory diseases, autoimmune diseases, and/or hypertensive disorders.
Thus, in especially preferred aspects of the inventive subject matter, compounds of the invention will have biological activities that include in vitro and in vivo inhibition of RNA-dependent RNA polymerases. It is especially preferred that compounds of the invention may function as a direct inhibitor for an RNA polymerase, and especially for HCV NS5B, but may also serve as a prodrug for delivery to a cell infected with a virus, thereby exhibiting further antiviral effect.
The term “antiviral effect” as used herein refers to both direct and indirect effects, wherein direct antiviral effects include inhibition of a viral polymerase, inhibition of a viral nuclease, inhibition of viral protein processing, inhibition of viral priming activity, inhibition of viral protein assembly, and inhibition of viral entry and/or exit from a cell. Indirect antiviral effects include stimulation of the immune system to increase an immune response, and especially contemplated indirect antiviral effects include modulation of the Th1/Th2 balance (e.g., relative increase of Th1 over Th2, or vice versa), or stimulation of IFN-gamma or IL-12 secretion.
It is particularly contemplated that compounds of the invention are administered to a patient at a concentration effective to reduce viral propagation and replication in a cell infected by the virus. Especially contemplated antiviral activities include at least partial reduction of viral titers of respiratory syncytial virus (RSV), hepatitis B virus (HBV), hepatitis C virus (HCV), herpes simplex type 1 and 2, herpes genitalis, herpes keratitis, herpes encephalitis, herpes zoster, human immunodeficiency virus (HIV), influenza A virus, Hanta virus (hemorrhagic fever), human papilloma virus (HPV), yellow fever virus, and measles virus.
The anti-HCV activity of the quinoxaline derivatives was tested by replicon and BVDV cell-line based assays. The HCV NS5B polymerase activity was tested as described below, and was further tested for its capability of inhibition of replication of the hepatitis C virus in a cell-line based HCV replicon assay as described in V. Lohmann, F. Komer, J.-O. Koch, U. Herian, L. Theilmann, R. Bartenschlager, “Replication of a Subgenomic Hepatitis C virus RNAs in a Hepatoma Cell Line”, Science , 1999, 285:110.
Pharmaceutical compositions of the invention contain a therapeutically effective amount of a compound of the invention as described herein, in combination with a pharmaceutically acceptable carrier. The term “a therapeutically effective amount” means an amount of the compound sufficient to induce a therapeutic effect, such as antiviral activity. Although the exact amount of active compound used in a pharmaceutical composition of the invention will vary with each compound and according to factors known to those of skill in the art, such as the nature of the carrier and the intended dosing regimen, it is anticipated that the compositions of the invention will contain sufficient active ingredient to provide a dose of about 100 ng/kg to about 50 mg/kg, preferably about 10 μg/kg to about 5 mg/kg in a unit dose. Any conventional dosage form may be used, including but not limited to tablets, lozenges, parenteral formulations, syrups, creams, ointments, aerosol formulations, transdermal patches, transmucosal patches and the like.
The compounds of the invention can be administered as the single therapeutic agent in the treatment regimen, or the compounds of the invention may be administered in combination with one another or with other active agents, including but not limited to immune response modifiers, antivirals, antibiotics, antibodies, proteins, peptides, and oligonucleotides.
Where compounds of the invention are administered in a pharmacological composition, it is contemplated that compounds of the invention can be formulated in admixture with a pharmaceutically acceptable carrier. For example, compounds of the invention can be administered orally as pharmacologically acceptable salts, or intravenously in a physiological saline solution (e.g., buffered to a pH of about 7.2 to 7.5). Conventional buffers such as phosphates, bicarbonates or citrates can be used for this purpose. Of course, one of ordinary skill in the art may modify the formulations within the teachings of the specification to provide numerous formulations for a particular route of administration. In particular, compounds of the invention may be modified to render them more soluble in water or other vehicle, which for example, may be easily accomplished with minor modifications (salt formulation, esterification, etc.) that are well within the ordinary skill in the art. It is also well within the ordinary skill of the art to modify the route of administration and dosage regimen of a particular compound in order to manage the pharmacokinetics of the present compounds for maximum beneficial effect in a patient.
In certain pharmaceutical dosage forms, prodrug forms of compounds of the invention may be formed for various purposes, including reduction of toxicity, increasing the organ or target cell specificity, etc. Among various prodrug forms, acylated (e.g. acetylated) derivatives, pyridinecarboxylate esters and various salt forms of the present compounds are preferred. One of ordinary skill in the art will recognize how to readily modify the present compounds to prodrug forms to facilitate delivery of active compounds to a target site within the host organism or patient. One of ordinary skill in the art will also take advantage of favorable pharmacokinetic parameters of the prodrug forms, where applicable, in delivering the present compounds to a targeted site within the host organism or patient to maximize the intended effect of the compound.
Compounds of the invention may be administered alone or in combination with other agents for the treatment of various diseases or conditions. Combination therapies according to the present invention comprise the administration of at least one compound of the present invention or a functional derivative thereof and at least one other pharmaceutically active ingredient. The active ingredient(s) and pharmaceutically active agents may be administered separately or together and when administered separately this may occur simultaneously or separately in any order. The amounts of the active ingredient(s) and pharmaceutically active agent(s) and the relative timings of administration will be selected in order to achieve the desired combined therapeutic effect.
EXAMPLES
1. Synthesis of Compounds
The following experiments are provided to give practitioners guidance on synthesis and use of exemplary compounds of the invention. However, it should be appreciated that various modifications of the below shown experiments may be made without departing from the inventive concepts presented herein.
Compound 1. To an ice-cooled stirred solution of L-5-hydroxytryptophan methyl ester hydrochloride (2.1 g, 9.53 mmol) in anhydrous methanol (120 ml) was added SOCl 2 (6.93 ml, 95.3 mmol) dropwise. The suspension was heated to reflux for 3 hours. After concentrating the mixture to dryness, the resultant residue was taken up in ethyl acetate and washed twice with saturated sodium carbonate and three times with brine. The organic layer was dried over anhydrous Na 2 SO 4 and concentrated to give 910 mg of product 1 as a pale yellow solid in 41% yield, which showed 100% LC-Mass purity; MS(ES) m/z 235 (M+1) + .
Compound 2. To a solution of 1 (717 mg, 3.06 mmol) in 1 ml of methanol was added 10 ml of concentrated NH 4 OH. The mixture was stirred for 4 hours at room temperature. The reaction was monitored by TLC (CHCl 3 —MeOH, 2:1) until the starting material 1 dispersed. After removing solvent the residue was dried at 50° C. under vacuum to give 657 mg of 2 as a light brown solid in 98% yield. MS(ES) m/z 219 (M+1) + . The crude product was used in the subsequent step without further purification.
Compound 3. A mixture of 3,4-diaminobenzoic acid (6.8 g, 44.7 mmol), 4-fluorobenzil (10.0 g, 40.6 mmol) and sodium acetate (6.7 g, 81.2 mmol) in 100 ml of acetic acid was boiled for 4 hours under a reflux condenser. The reaction mixture was poured into 500 ml of water while still hot, and the mixture was cooled to room temperature. The precipitate was filtered, and the filtrate was dried under vacuum for 3 hours. The crude product was then dissolved in 400 ml of 3N sodium hydroxide solution, and the product precipitated again by addition of 3N hydrochloric acid solution (400 ml) to pH 3. The compound 3 was obtained in 100% yield as a light brown solid by filtration and dried under vacuum at 50° C. overnight. LC-Mass: 100% purity; TLC Rf(0.85, CHCl 3 —MeOH, 5:1); MS(ES) m/z 362.9 (M+1) + , 361.5 (M−1) − . 1 H NMR (DMSO d6 ) δ 7.02–7.12 (m, 4H), 7.38–7.50 (m, 4H), 8.19 (d, 1H, J=5.4 Hz), 8.38 (d, 1H, J=5.4 Hz), 8.78 (s, 1H).
Compound 4. To a solution of 3 (98 mg, 0.27 mmol), O-benzotriazol-1-yl-N,N,N′,N′-tetramethyluronium tetrafluoroborate (TBTU) (132 mg, 0.41 mmol) and L-5-hydroxytryptophan amide (90 mg, 0.41 mmol) in 5.0 ml of DMF was added diisopropylethylamine (0.05 ml) dropwise. The reaction mixture was stirred at room temperature for 4 hours and monitored by TLC (CHCl 3 —MeOH, 5:1). The reaction mixture was quenched by adding 5 ml of water, and the resulting mixture was adjusted to pH 9 by addition of saturated sodium carbonate. The product was extracted with ethyl acetate and washed with brine. The organic layer was dried over anhydrous Na 2 SO 4 and concentrated to dryness. The residue was purified by flash chromatography on a silica gel column using a gradient eluent from 9%–17% methanol in chloroform to give 109 mg (72%) of compound 5 as a pale yellow foam, which showed 96.7% LC-Mass purity. MS(ES) m/z 586 (M+Na) + .
Compound 5. To a solution of 3 (192 mg, 0.53 mmol), O-benzotriazol-1-yl-N,N,N′,N′-tetramethyluronium tetrafluoroborate (TBTU) (340 mg, 1.06 mmol) and L-5-hydroxytryptophan methyl ester (174 mg, 0.74 mmol) in 10 ml of DMF was added 0.55 ml of diisopropylethylamine dropwise. The mixture was stirred at room temperature for 16 hours and monitored by TLC (CHCl 3 —MeOH, 10:1). The reaction mixture was quenched by adding 5 ml of water, and the resultant mixture was adjusted to pH 9 by the addition of saturated sodium carbonate. The mixture was extracted with ethyl acetate and washed with brine. The organic layer was dried over anhydrous Na 2 SO 4 and concentrated to dryness. The residue was purified to give compound 5 in 51% yield by flash chromatography on a silica gel column using a gradient eluent from 1%–10% methanol in chloroform to give 36.6 mg (51%) of product 5 as a pale yellow foam. MS(ES) m/z 579 (M+H) + .
Compound 6. To an ice-cooled solution of 5 (114 mg, 0.197 mmol) in 5 ml of N,N-dimethylformamide was added 1 ml of 3N sodium hydroxide. The mixture was stirred at room temperature for 2 hours and monitored by TLC (CHCl 3 —MeOH, 5:1) and API 150EX mass spectrometer. The reaction mixture was quenched by the addition of 3 ml of 1N hydrochloric acid. The mixture was then concentrated to dryness, taken up in EtOAc, and washed twice with water and twice with brine. The organic phase was dried over anhydrous MgSO 4 and concentrated to dryness. The residue was purified by flash chromatography on a silica gel column using a gradient eluent from 17%–33% methanol in chloroform. The compound 6 was obtained in 94.6% yield (105 mg) and showed 93.73% HPLC purity. MS(ES) m/z 563 (M−H) − .
Compound 7 was prepared by a similar procedure as described above for compound 5 in 100% yield and showed 98.5% HPLC purity. MS(ES) m/z 563 (M+H) + .
Compound 8 was prepared by saponification as described above for compound 6 in 82.6% yield and showed 97.4% HPLC purity. 1 H NMR (CD 3 OD) δ 3.31–3.40 (m, 1H), 3.48–3.55 (m, 1H), 5.00–5.08 (m, 1H), 6.95–7.15 (m, 6H), 7.20 (s, 1H), 7.30 (d, 1H, J=7.8 Hz), 7.50–7.60 (m, 4H), 7.70 (d, 1H, J=7.8 Hz), 8.10–8.20 (m, 2H), 8.48 (s, 1H), 10.30 (s, 1H). MS(ES) m/z 549 (M+H) + , 547 (M−H) − .
Compound 9. To a solution of 7 (116 mg, 0.2 mmol) in 3 ml of dimethylformamide was added 5.0 ml of concentrated ammonium hydroxide. The mixture was stirred at room temperature for 16 hours and monitored by TLC (CHCl 3 —MeOH, 5:1). The mixture was concentrated to dryness after the starting material dispersed. The residue was purified by flash chromatography on a silica gel column eluting with 10% methanol in chloroform to give 90 mg (83%) of product 9 as a pale yellow foam. The product showed 99.4% HPLC purity. MS(ES) m/z 547 (M−H) − .
Compound 10 was prepared in 92% yield as a brown solid by the similar procedure as described above for compound 3. MS(ES) m/z 329 (M+H) + .
Compound 11. The carboxylic acid derivative 10 was coupled to L-tryptophan methyl ester hydrochloride in the usual manner as described above for compound 5 to give compound 11 as a pale yellow foam in 83.6% yield. MS(ES) m/z 529 (M+H) + .
Compound 12 was prepared in 69%-isolated yield by saponification of methyl ester 11 and followed by column purification. The product showed 91.99% HPLC purity.
Compound 13 was prepared as a pale yellow foam in 77.4% isolated yield by coupling phenazine-2-carboxylic acid with L-tryptophan methyl ester hydrochloride in the usual manner as described above for compound 5. MS(ES) m/z 425 (M+H) + .
Compound 14 was prepared in 77%-isolated yield by saponification of methyl ester 13 and followed by column purification. The product showed 98% HPLC purity. 1 H NMR (CD 3 OD) δ 3.32–3.44 (m, 2H), 3.50–3.62 (m, 1H), 7.01 (t, 1H, J=7.2 Hz), 7.06 (t, 1H, J=7.2 Hz), 7.21 (2, 1H), 7.32 (d, 1H, J=8.1 Hz), 7.65 (d, 1H, J=7.8 Hz), 7.92–8.01 (m, 2H), 8.10–8.30 (m, 4H), 8.57 (s, 1H), 10.33 (s, 1H). MS(ES) m/z 411 (M+H) + , 409 (M−H) − .
Compound 15. To a solution of cyclohexanecarboxaldehyde (2.16 ml, 17.8 mmol) in 30 ml of anhydrous tetrahydrofuran (THF) was added trimethylsilyl cyanide (2.86 ml, 21.36 mmol) under an argon atmosphere. 0.44 ml of 1.6 M n-BuLi in hexane (0.71 mmol) was added to an ice-cooled reaction mixture under stirring. The reaction mixture was then stirred at room temperature for 2.5 hours, and then quenched by addition of 10 ml of water. After evaporating THF the residue was extracted with diethyl ether (30 ml×3) and the combined organic layer was dried over anhydrous Na 2 SO 4 . The solvent was evaporated to dryness. The oily residue was dissolved in 40 ml of anhydrous diethyl ether containing 5 g of MgSO 4 . The mixture was stirred at room temperature for 3 hours, and then filtered through a pad of silica gel and Na 2 SO 4 . The solvent was evaporated, and the residue was dried overnight under vacuum at 40° C. to give 3.71 g (98.5%) of trimethylsilyloxymethylcyclohexane 15 as a yellowish oil.
Compound 16. To an ice-cooled solution of 15 (1.5 g, 7.1 mmol) in 30 ml of diethyl ether was added 3.0 M phenylmagnesium bromide (7.1 ml, 21.29 mmol) dropwise under an argon atmosphere. The reaction mixture was stirred at room temperature for 3 hours and monitored by TLC (Hexanes-EtOAc, 5:1). The cooled reaction mixture was quenched by the addition of 10 ml of water and 15 ml of 10% HCl. The resultant mixture was extracted with AcOEt (40 ml×3). The combined organic layer was washed with brine (30 ml×3) and dried over anhydrous Na 2 SO 4 . The solvent was evaporated under vacuum. The oily residue was again dissolved in 20 ml of anhydrous THF and 5 ml of 10% HCl. The mixture was stirred at room temperature for 2 hours. THF was evaporated, and the residue was extracted with AcOEt (50 ml×3). The organic phase was washed with brine (30 ml×3), dried over Na 2 SO 4 , and concentrated. The oily residue was purified by flash chromatography on a silica gel column using Hexanes-AcOEt (5:1) as eluent to give 0.39 g of compound 16 in 25% yield.
Compound 17. A solution of 16 (380 mg, 1.74 mmol), copper(II) acetate (31 mg, 0.174 mmol), and ammonium nitrate (174 mg, 2.18 mmol) in 5 ml of 80% (v/v) aqueous acetic acid solution was stirred at room temperature for one hour under an argon atmosphere and then refluxed for 2 hours. The reaction was monitored by TLC (Hexanes-AcOEt, 5:1). The organic solvents were evaporated, and the residue was extracted with diethyl ether (30 ml×3). The combined ether layer was washed with saturated aq. NaHCO 3 (20 ml×2) solution and brine (30 ml×3), and dried over anhydrous Na 2 SO 4 . The solvent was evaporated, and the residue was purified by flash chromatography on a silica gel column using Hexane-AcOEt (8:1) as eluent to give 211 mg of compound 17 in 56% yield.
Compounds 18 and 19 were prepared in 90% yield by a similar condensation procedure as described above as an isomeric mixture of 18 and 19 in a 3:1 ratio.
Compound 20/22 was prepared as described above for compound 5 as an isomeric mixture in 83% yield. Compound 21/23 was synthesized as described above for compound 6 in 53% yield.
Similarly, compounds 24 and 25 may be prepared from the corresponding alpha-hydroxy ester, as shown below:
2. Assay of De Novo RNA Synthesis Activity for HCV NS5B Polymerase
HCV NS5B was derived from a cDNA clone encoding HCV-1b CON1 strain, and was expressed and purified from E. coli . Various [α- 33 P]rNTPs (3000 Ci/mmol) were purchased from Perkin Elmer. 3′-Deoxy ribonucleosides, their 5′-triphosphates and dinucleotide primers were from Sigma, TriLink (San Diego, Calif.) or ICN Biochemicals. All other reagents were of the highest grade available from ICN, Sigma, Fisher, or Ambion.
An HCV mini-genome of 2.1-kb contains an entire 5′-UTR (untranslated region), part of NS5B sequence and an entire 3′-UTR was constructed from an internal deletion between two KpnI sites on the HCV replicon plasmid, pFK389/NS3-3′. To generate the in vitro transcribed mini-genome RNA, the plasmid DNA was linearized with AseI and ScaI and transcribed in vitro using a MegaScript kit (Ambion, Austin, Tex.). After phenol-chloroform extraction and isopropanol precipitation, the RNA was resuspended in RNase-free water and stored at −80° C. before use. This HCV strain CON1-based template was used for the standard NS5B-catalyzed RNA synthesis assay.
A standard NS5B activity assay was performed at 23C in a total volume of 25 μl. The reaction buffer contained 50 mM Tris, pH 7.0, 10 mM MgCl 2 , 50 mM NaCl, 5 mM DTT (add fresh) and 0.05 mg/ml BSA. 0.4 μg of the RNA template was incubated with NS5B enzyme (250 nM) before adding a mixture of radiolabeled nucleotide (0.2 μCi) and cold nucleotide cocktail to initiate a reaction. The assay was incubated for 1 hr and terminated by addition of 75 μl of 5% trichloroacetic acid (TCA) and 0.05% pyrophosphate solution. The quenched solution was incubated at room temperature for 10 min to precipitate out polymeric products and subsequently transferred to a 96-well white GF/B filter microplate (Packard Instrument) using a Packard Filtermate Universal Harvester. The filter plate was washed five times by water and one time by ethanol before vacuum drying. 40 μl of liquid scintillation cocktail (Packard MicroSint™) was added to each well. Radioactivity incorporated into the product was counted in a 96-well format using a Packard TopCount. IC 50 values, defined as the inhibitor concentration to suppress 50% of NS5B activity, were determined by varying the compound concentration. The results in Table 1 are data obtained using the HCV NS5B assays described above.
HCV Replicon Assay. The replicon cells (Huh-7) contain replicating HCV replicon RNA, which was modified in the structural region (replacing the structural region with a neomycin resistance marker). Survival of the replicon cells under G418 selection relies on the replication of HCV RNA and subsequently expression of neomycin phosphoryltransferase. The ability of modified nucleoside libraries and compounds to suppress HCV RNA replication was determined using the QuantiGene™ Assay Kit (Bayer Diagnostics, Tarrytown N.Y.). The assay measures the reduction of HCV RNA molecules in the treated cells. Replicon cells were incubated at 37° C. for 3 days in the presence of nucleoside libraries and compounds before being harvested for detection. The assay protocol was modified based on literature procedure (V. Lohmann, F. Komer, J. O. Koch, U. Herian, L. Theilmann, R. Bartenschlager, Science , 1999, 285, 110–113). The HCV subgenomic replicon cell line was provided by Dr. R. Bartenschlager.
Assay for Inhibition of BVDV . The nucleoside libraries and compounds were tested utilizing the modified protocol (V. B. Vassilev, M. S. Collett, R. O. Donis, J Viol . 1997, 71, 471–478; S. G. Bagginski, D. C. Pevear, M. Seipel, S. C. C. Sun, C. A. Benetatos, S. K. Chunduru, C. M. Rice, M. S. Collett, Proc. Natl. Acad. Sci. U.S.A . 2000, 97, 7981–7986). Bovine viral diarrhea virus (BVDV) (strain NADL) was provided by Dr. Ruben Donis and propagated in MDBK cells (ATCC).
TABLE 1
HCV Replicon and NS5B Inhibitory Activities
HCV Replicon
HCV NS5B
R
X
(EC50)
(IC50)
OH
OH
10–50
μM
<10
μM
OCH 3
OH
10–50
μM
<10
μM
NH 2
OH
10–50
μM
<10
μM
OH
H
>50
μM
<10
μM
OCH 3
H
10–50
μM
>50
μM
NH 2
H
10–50
μM
<10
μM
HCV
HCV
Replicon
NS5B
R1
R2
X
(IC50)
(EC50)
OH
>50
μM
<10
μM
OMe
>50
μM
>50
μM
OH
10–50
μM
—
OH
>50
μM
<10
μM
—
10–50
μM
—
>50
μM
—
>50
μM
OH
>50
μM
>50
μM
>50
μM
>50
μM
>50
μM
>50
μM
OH
10–50
μM
<10
μM
—
<10
μM
<10
μMA
—
10–50
μM
—
It will be apparent to those skilled in the art that modifications besides those already 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 specification and claims. Moreover, in interpreting the specification and claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced.
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The invention provides substituted quinoxalines having the general formulas
where R 1 , R 2 , R 3 , and R 4 are, inter alia, alkyl, aryl, or heteroaryl groups; Z is NH or O; and X is, inter alia, COOH or CONH 2 . The compounds of the invention have antiviral and immunomodulatory activity and are useful for treating infectious diseases, particularly viral infections.
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FIELD OF THE INVENTION
This invention relates to apparatus for accessing bone for conveying fluids, solids or medical devices thereto. More particularly, it involves a system for access to bone or other hard tissue, where the system has a manipulable or steerable end to reach radially disposed sites.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 represents information known in the art and is referenced in the Background of the Invention. FIGS. 2-16B diagrammatically illustrate aspects of the present invention. Variation of the invention from that shown in the figures is contemplated.
FIG. 1 is a plan view of various bone access tools sold by Cook Medical, Inc.
FIG. 2 is a perspective view of a high pressure injection system that may be used in connection with the present invention.
FIGS. 3A-3C are perspective views of a cannula and stylets that may be used with the high pressure injection system.
FIGS. 4 A- 4 C″ are perspective views in which FIGS. 4A and 4B show access and implant material delivery in a vertebral body site, respectively; FIGS. 4 C- 4 C″ depict varying access approaches in a long-bone application.
FIGS. 5A-5C are perspective views of manipulator components.
FIG. 6 is a perspective view of a catheter/conduit with a curved end.
FIG. 7 is a perspective view of a manipulator-conduit combination.
FIG. 8 is a perspective view of a straight catheter/conduit.
FIGS. 9A-9D are perspective views of various tips for a conduit.
FIG. 10 is a perspective view of an alternate introduction section from that shown in FIG. 8 for the conduit pictured.
FIG. 11 is a perspective view of an obturator usable in the present invention.
FIG. 12 is a perspective view of an alternate obturator with a flexible distal end; FIG. 13 is a close-up of the obturator distal end shown in FIG. 12 .
FIGS. 14A-14D are perspective views of active tips for an obturator.
BACKGROUND OF THE INVENTION
The mineralized tissue of the bones of the human skeletal system are generally categorized into two morphological groups: “cortical” bone and “cancellous” bone. The outer walls of all bones are composed of cortical or “compact” bone. This tissue is characterized by a dense structure with only microscopic porosity. Cancellous or “trabecular” bone is found in the interior of bones. This tissue is composed of a lattice of interconnected slender rods and plates called “trabeculac.”
Injectable Polymethylmethacrylate (PMMA), set within the trabeculae, has been used for supplementing cancellous bone, especially for anterior and posterior stabilization of the spine in metastatic disease. See Sundaresan, et al., “Treatment of neoplastic epidural cord compression by vertebral body resection and stabilization,” J Neurosurg 1985;63:676-684; Harrington, “Anterior decompression and stabilization of the spine as a treatment for vertebral collapse and spinal cord compression from metastatic malignancy.” Clinical Orthodpaedics and Related Research 1988;233:177-197; and Cybulski, “Methods of surgical stabilization for metastatic disease of the spine.” Neurosurgery 1989;25:240-252. Deramond et al., “Percutaneous vertebroplasty with methyl-methacrylate: technique, method, results [abstract],” Radiology 1990; 117 (suppl): 352, among others, have described the percutaneous injection of PMMA into vertebral compression fractures by the transpedicular or paravertebral approach under CT and/or fluoroscopic guidance.
Percutaneous vertebroplasty is desirable from the standpoint that it is minimally invasive as compared to the alternative of surgically exposing a hard tissue site to be supplemented with PMMA or other filler. Several procedures are known for accessing a desired site in the cancellous bone of a vertebral body (or for that matter other cancellous bone) to deliver hard tissue implant material to stabilize—or build up—a site once expanded as taught by U.S. Pat. Nos. 6,280,456; 6,248,110; 5,108,404 and 4,969,888.
To gain access to a hard tissue implantation site, as described in U.S. Pat. No. 6,019,776 and 6,033,411, a straight needle or cannula in combination with a stylet may be employed. Once access is achieved and the stylet is removed from the cannula, hard tissue implant material is delivered through the same.
Another approach for biopsy sampling or material infusion is employed with a product sold by Cook Medical, Inc. The approach involves the use of a straight cannula/stylet combination for gaining access to the cancellous bone and a curved Nitinol (NiTi) needle for accessing a site that is radially oriented from the end of the cannula. The full set of instruments sold by Cook under the OSTEO-RX™ produce line is shown in FIG. 1 . It includes straight cannula 2 , a stylet 4 and obturator 6 for receipt in the cannula—each made of stainless steel. It further includes a curved Nitinol needle 8 and a flexible stylet 10 for receipt in the curved needle. The cannula/introducer needle 2 is a 10-gage member, 10 cm in length; the curved needle is a 13-gage member, 19 cm in length.
In use, cancellous bone tissue is accessed by traversing compact bone tissue with the stylet/cannula combination 12 , each having a beveled end as highlighted in the magnified end images. Once a desired depth within the bone is reached, the stylet is withdrawn. The obturator 6 may be placed in cannula 2 in order to close-off the cavity temporarily or clear out tissue invading its space upon withdrawal of stylet 4 . At this point, curved needle 8 is introduced into cannula 2 .
Made of superelastic material, the needle straightens as the walls of the cannula apply force against it. Whether stylet 10 is inserted before or after loading the cannula with the curved (now straightened) needle 8 , the combination is advanced in cannula 2 so that the distal end of the stylet, needle combination 14 bores through cancellous bone tissue a the desired delivery site. At this point, stylet 10 is removed to allow infusion of implant material under pressure to the site. Alternately, stylet 10 is only partially withdrawn and needle 8 advanced further to take a biopsy sample.
Whatever the intent of the procedure, needle 8 is then withdrawn at least into the body of the cannula so the straight cannula section may then be removed from the patient's body. For certain reasons, it may be desirable to remove the needle from the cannula altogether, e.g. for later infusion of material through the canula when the needle is used for acquiring a biopsy sample. In either case, no conduit is left behind to allow infusion of an implant material specifically at the end of the curved needle's tract.
Especially when withdrawing the curved needle from the cannula (but also in loading it into the cannula), the system presents high risk to users. It has been observed that the stiffness of curved needle 8 and amount of energy it stores upon straightening mandates extreme caution in handling, lest injury result from its curved end 16 returning to its unconstrained, curved shape—impaling the user. In addition to the user safety issues the device presents, the difficulty presented in straightening needle 8 within cannula 4 produces significant frictional forces between the members resulting in less than optimal actuation and control of the system. Furthermore, the insertion or removal (at least partial removal) activity of the curved needle into and out of the cannula occurs when cannula 2 is set within a patient's body makes any such manipulation more difficult.
Except for the present invention, no known solution has been developed that provides functionality like the above-referenced system, but without the noted problems with safety and ease use. As such, the present invention is particularly suited to meet the needs of bone access at sites that are radially located from an access path through harder bone tissue. It does so through operation principles which differ from those of the Cook system. Accordingly, a conduit and core member used in the present invention each differ in their unstressed shape and material properties as compared to those in the other system.
SUMMARY OF THE INVENTION
The present invention is a bone access system offering radial access to sites with reduced user risk and ease of use. The inventive system employs a flexible (semi-rigid) conduit that is formed into a curved shape by a curved core wire once the end of each item is advanced beyond the end of a cannula which restrains the core member (via the intermediately-located conduit). The core wire has a relatively low stiffness so it is easily set within the cannula (either together with the conduit or after the conduit has been placed therein). Various types of material may be employed for the curved core wire or guide wire including titanium, nickel-titanium, steel alloys or plastic/composite members.
In any case, the core member can be engineered to have a stiffness much lower than the curved needle in the above-reference Cook device since it need not be a large tubular member capable of delivering material therethrough. In the present invention, that task is left to the flexible conduit that is directed by the core member.
Additionally, the present invention is suited for use with an actuation sheath between the core member and conduit that is capable of independently straightening the preformed section of the wire. This allows for articulation of the curve independent of its relation to the end of the cannula. Yet another aspect of the invention provides an active tip (e.g., a drill bit or chisel) at the end of the core member. Such an active tip may be actuated by twisting, oscillating or other motion relative to the conduit to assist in advancing the co-axial conduit through bony matter. Still further, the invention may employ a serrated conduit end, possibly provided by a metal crown to assist in obtaining a bone biopsy sample.
A cannula (usually with a stylet) is used to provide a desired straight-line access path through hard bone. Then, the conduit and core wire of the present invention are advanced together to traverse cancellous bone to reach a desired site positioned radially from the end of the cannula. Upon removal of the core member, flowable material, a medical device, etc., may be introduced through the conduit. Alternately, a biopsy sample may be obtained once the core member is retracted.
Whatever the case, the present invention includes systems comprising any of the features described herein. Methodology described in association with the devices disclosed also forms part of the invention. Such methodology may include that associated with completing a vertebroplasty procedure and use of such auxiliary equipment as described below or otherwise available. The invention may be used in other methods as well. For instance, the invention further comprises such hardware and methodology as may be used in connection with that described which is incorporated by reference.
DETAILED DESCRIPTION OF THE INVENTION
Before the present invention is described in detail, it is to be understood that this invention is not limited to particular variations set forth and may, of course, vary. Various changes may be made to the invention described and equivalents may be substituted without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, process act(s) or step(s), to the objective(s), spirit or scope of the present invention. All such modifications are intended to be within the scope of the claims made herein.
Methods recited herein may be carried out in any order of the recited events which is logically possible, as well as the recited order of events. Furthermore, where a range of values is provided, it is understood that every intervening value, between the upper and lower limit of that range and any other stated or intervening value in that stated range is encompassed within the invention. Also, it is contemplated that any optional feature of the inventive variations described may be set forth and claimed independently, or in combination with any one or more of the features described herein.
All existing subject matter mentioned herein (e.g., publications, patents, patent applications and hardware) is incorporated by reference herein in its entirety except insofar as the subject matter may conflict with that of the present invention (in which case what is present herein shall prevail). The referenced items are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such material by virtue of prior invention.
Reference to a singular item, includes the possibility that there are plural of the same items present. More specifically, as used herein and in the appended claims, the singular forms “a,” “and,” “said” and “the” include plural referents unless the context clearly dictates otherwise. It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation. Unless defined otherwise herein, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
Turning now to FIG. 2 , a system suitable for vertebroplasty or another hard tissue implantation procedure is shown. The system includes a high pressure applicator 20 comprising first and second columns, a conduit 22 for connection to the applicator and a cannula/stylet combination 24 .
Applicator 20 comprises a first column 26 and a second column 28 . A plunger head 30 is sized to freely pass into introduction section 32 (to avoid trapping air bubbles) and into a vessel section 34 where a frictional seal may be formed. The plunger is driven forward to extrude implant material provided within the vessel section out of nozzle 36 . This may be accomplished via a threaded section 38 and a mating interface (not shown) within column 28 or otherwise. Further examples of acceptable pressure applicators for hard tissue implantation applications are provided in U.S. Pat. No. 6,383,190 which is incorporated herein by reference.
For use in vertebroplasty and other bone augmentation procedures, PMMA implant material may be preferred. Preferably, compositions as described in U.S. Pat. Nos. 6,232,615 and 6,309,420, each incorporated herein by reference, including contrast agent and particles to facilitate tracking the progress of injected material in-process are employed.
A non-compliant tube 22 is preferably provided for connection to the pressure application as shown (possibly via luer fittings 40 ) to allow remote delivery of implant material via a cannula 42 as shown in FIG. 3 A. The cannula may be attached to the conduit using a complimentary luer fitting 40 or otherwise. Details regarding and advantages of utilizing a non-compliant delivery conduit are set forth in U.S. Pat. No. 6,348,055.
As provided in further detail in FIGS. 3A-3B , the cannula/stylet combination includes a cannula with handle portions 44 and a tubular body 48 . The tubular portion includes a chamfered end 50 . The stylet 52 shown in FIG. 3B also includes a handle portion 46 and includes threads 54 to interface with threads 40 on handle portion 44 of the cannula. A stylet shaft 56 that terminates in a single-beveled tip 58 is shown in FIG. 3 B. The stylet 52 in FIG. 3C terminates in a threaded distal tip 60 . Other suitable stylet configurations, such as sold by the assignee of the present invention and as described in U.S. Pat. No. 6,033,411 and U.S. patent application Ser. No. 09/409,948, filed Sep. 30, 1999, each entitled, “Precision Depth Guided Instruments For Use In Vertebroplasty,” or U.S. patent application Ser. No. 09/876,387, entitled, “Cannula System of Hard Tissue Implant Delivery,” filed Jun. 6, 2001, all of which are incorporated herein by reference, may be employed.
With such tools adapted for precutaneous bone access, a surgeon initially identifies a landmark with the aid of fluoroscopy of other imaging technique. Next, an injection is given to anesthetize the skin where insertion will occur. Local anesthesia will typically also be administered to the target site as well. After sufficient time has passed to effectively anesthetize the skin, an incision is made through the skin with a scalpel.
A combined stylet and cannula combination 24 is then inserted through the incision and advanced using a translation motion with no torquing, until the tip 60 of the stylet abuts the hard bone tissue to be traversed. Once contact has been made, the cannula tube is then grasped with a pair of hemostats and fluoroscopy/imaging is used to assess the position of the cannula/stylet with regards to the vertebra. The hemostats are used to allow the hands of the user to be removed form the field in which the imaging radiation will be applied. With the aid of medical imaging (possibly applied along various trajectories), the cannula/stylet 24 are positioned with the desired orientation for passing into the body of the bone.
If the advancement of the stylet and cannula does not proceed along the intended pathway, the stylet 52 may be reversed rotated while preventing rotation of the cannula 42 to maintain it in position and remove the stylet. Then, a stylet as shown in FIG. 3C , may be employed. With beveled tip 58 , the operator can rotate the sytlet to position the tip in a direction toward which he/she wishes to migrate the stylet. Once the orientation of the stylet 52 and cannula 42 , having been advanced over the stylet, has been satisfactorily set, the fluoroscopy/imaging is discontinued, the hemoststs are removed and the operator carefully gasps the cannula/stylet being careful not to alter the orientation. The stylet with beveled tip 58 is then removed and replaced by the stylet with self-tapping threads 60 . Grasping the combination handle 44 / 46 , and optionally the cannula tube 48 , the operator then proceeds to both push translationally and torque the combination handle to begin the threading the stylet end 60 into hard bone tissue.
After “biting” into the bone with a few turns of the self-tapping threads, the operator's hands are removed and the devices maintain their position by the support provided by the bone surrounding the threads. The devices/instruments are again viewed fluoroscopically of otherwise imaged both along the longitudinal axis of the cannula/stylet and laterally to determined the depth of the instruments. If the desired depth and placement has not yet been achieved, imaging is discontinued, and the cannula/stylet are further torqued or otherwise advanced into the cancellous bone until the tip of the cannula has been positioned in the desirable location.
Upon achieving the desired placement of the cannula at sat a site for treatment, the operator reverse rotates the stylet 52 to remove it from the cannula 42 , while preventing rotation of the cannula. The cannula at this state is effectively press-fit into the bone site which aids the operator in preventing its rotation. Once the stylet has been completely removed for the cannula, fluoroscopic imaging/viewing of the cannula may optionally be performed to assure that the cannula did not move during the removal of the stylet.
Optionally, a contrast agent, e.g. a product known as OMNIPAQUE 300 available from Nycomed in Princeton, N.J., may be injected through the cannula and the flow of the contrast agent is viewed fluoroscopically or with other imaging in order to ascertain that the tip of the cannula has not been placed in a vein or other significant vessel. Preferably, the contrast agent is injected through tubing connected to the cannula. When tubing is used, it is preferably of a smaller length and diameter than tubing that is used for injection of implant material. Contrast agent must be flushed out of the site prior to injection of the implantation material, so it is preferable to inject only a small volume of the contrast agent. Viewing of the flow of the contrast agent helps to identify the shape of the body into which the injection of implant material is to be performed, as well as to locate where the major veins lie. After completing the flow of the contrast agent, the remnants of the contrast agent are flushed by injecting a flushing solution (e.g. saline) through the cannula tube 48 , using a syringe or other injector. The imaging is preferably discontinued for this step. The contrast agent is flushed out so that it does not occlude, cloud, or otherwise compete with the viewing of the radiopacity of the implant material when it is placed.
Whether or not such steps are taken to verify cannula placement at this stage, utilizing the present invention, it is possible to directly reach tissue sites as shown in FIGS. 4 A- 4 C″ with a tube 70 once the cannula 42 is set in place. (In either case, the verification steps taken above may be repeated or performed for the first time, but for the bone catheter described.)
The sites shown in FIGS. 4 A- 4 C″ are radially or remotely located from the distal end 50 of the cannula. They are reached by way of a catheter tube 70 which is received within and extend beyond cannula tube 48 . In FIG. 4A , a manipulator 72 is shown received by the catheter 70 , abutting catheter fitting 74 . Details of the manipulator follow in connection with the description of FIGS. 5A-5C . Catheter fitting 42 may take the form of a luer fitting to interface either directly with conduit 22 or injector 20 at nozzle 36 .
In either case, once emplaced, the extended conduit 70 allows an operator to reach sites removed from the access port formed by and aligned with the axis of the cannula. In FIGS. 4A and 4B , by tunneling through cancellous bone in the vertebral body, a site opposite the entry region of the catheter and the distal tip 50 of the cannula is available at the distal end 76 of catheter 70 .
Generally, such a site will be reached by first advancing the manipulator member (or merely an internal core member or guide wire) and then advancing the catheter over the same or by simply advancing the manipulator and catheter together relative to cannula 42 . For this purpose, the end of the manipulator (possibly the end of a core member or guide wire, but preferably the end of an obturator 140 integral with or placed over the manipulator) may include a tip or “beak” adapted for traversing cancellous bone tissue.
Once manipulator 72 (or any basic curved wire and/or any obturator placed therein) is removed, as shown in FIG. 4B , a bolus of implant material can be delivered.
This may be accomplished by connecting the applicator 20 directly or via conduit 22 to catheter fitting 74 and actuating the applicator. With the exemplary applicator shown, actuation is accomplished by rotating first and second columns, 26 and 28 , relative to each other to cause drive piston 30 into vessel section 34 via threading 38 to expel flowable implant material.
By retracting catheter 70 in the direction of the arrow shown in FIG. 4B , most or all of the vertebral body can be filled with implant material. Retracting or drawing catheter 70 back in this manner while continuing to flow implant material therethrough offers a significant advantage over known approaches where both sides of a vertebral body (or another bony structure) need to be accessed to achieve the same coverage.
Another potential use of the catheter is illustrated in FIGS. 4 C- 4 C″. By rotating the manipulator used to control the trajectory of the catheter 70 as it is advanced beyond cannula tip 50 to pass or burrow through bone, different remote locations may be accessed. Each of FIGS. 4C , 4 C′ and 4 C″ indicate different access locations by virtue of the direction in which the catheter/manipulator is facing (as indicated by directional stop or handle 98 ) and the extent to which cannula body 48 is inserted in the bone. The trajectory of the catheter is preferably set or corrected by first withdrawing it and the internal manipulator into the cannula then adjusting the orientation, before re-penetrating the cancellous bone with the catheter and manipulator together or the manipulator alone. Such manipulation may be called for in light of the fact that access (or approach) within the cancellous may be limited by anatomy. That is to say, surrounding tissue (tendons, ligaments, arteries, sensitive organs, etc) or the morphology of the bone site itself may dictate taking any number of paths to reach a desired site.
For whatever reason, the present invention offers a solution to delivering implant material (or devices) to pin-point location(s) that may not feasibly be reached by a direct-line system. The curved or radially remote access options offered by the present invention are therefore particularly useful. Alternatively, or additionally, a retract-and-deliver approach may be utilized as described in connection with the action depicted in FIG. 4B in order to distribute delivery of material.
Regardless, a preferred assembled manipulator device 72 to assist in catheter end placement is shown in FIG. 7 . The manipulator comprises a slotted housing 80 with an actuator or core wire 82 attached at a distal point 84 as depicted in FIG. 5B by dashed lines. A groove or slot 86 is configured to receive a slider member 88 such as that shown in FIG. 5 C. The slider/slide handle may have one or more sections with a textured interface 90 to provide positive traction with the same. A hollow actuator sheath 92 is attached to slide handle 88 such that core/guide wire 82 may pass through the body of the sheath/handle combination.
To assemble the items as shown in FIG. 5A , sheath 92 is passed through a distal guide portion 94 of housing 80 and slide handle 88 is set within grove 86 . Guide wire 82 is then set in place, affixed at point 84 as described above to secure the pieces.
Core/guide wire 82 preferably comprises Nitinol (NiTi alloy), another superelastic material or at least a highly flexible material such as noted above. In the variation of the actuator shown, core wire 82 includes a pre-set or pre-formed curved distal tip 96 . Sheath 92 is configured to be more stiff or have greater stiffness than core wire 82 . Still, as referenced variously herein, a core wire 82 may be used alone to guide catheter 70 , or in connection with such hardware as shown in FIGS. 5A-5C .
When taken together, when slide handle 88 is retracted within slotted housing 80 as shown in FIG. 5A , sheath 92 is retracted to expose a curved end 96 of core member 82 . This allows tip 96 to return to or take its pre-set or pre-formed shape. Upon advancing handle 88 as indicated in dashed lines in FIG. 5A , sheath 92 advances to force the core wire into a straightened configuration.
As alluded to with respect to FIGS. 4 C- 4 C″, by varying the direction in which the actuator 72 is oriented relative to cannula 42 , the direction in which the catheter 70 (which overrides the actuator) is directed upon advancement from the end of the cannula may be varied. Stop or rest 98 may provide a visual indication in this regard as the catheter is forced or burrows through hard cancellous bone or other “hard” tissue, including cartilage.
Another feature may be employed as well in order to reach distinct sites (such as the locations indicated in FIGS. 4 C- 4 C″). Namely, the extent of retraction/advancement of slide handle 88 within housing 80 may be controlled to vary the degree of curvature attained by the end 96 of core member 82 and hence an end 100 of catheter 70 which overrides the same.
FIG. 6 shows an exemplary catheter 70 as may be used in the present invention in isolation. It is shown with a pre-formed, curved end 100 . With proper alignment, using such an end may provide assistance in reaching a curved state when traversing hard/bony tissue in connection with curved end 96 of core wire.
Whether provided with a curved end, or an initially straight end as shown in FIG. 8 , when cannula 70 is set over manipulator 72 as shown in FIG. 7 , the combination may be articulated from curved to straight depicted in like matter to that shown in FIG. 5 A. Utilized in this manner, catheter positioning as shown in FIGS. 4A-4C may be achieved by setting the curvature of the catheter via the manipulator as desired and traversing or burrowing through tissue.
Note, however, that similar utility may be achieved absent the use of an actuator sheath. Catheter 70 may be set directly over the pre-formed core wire 82 used in isolation. In which case, cannula body 48 can be used as a restraining member, allowing the catheter and core wire to curve as indicated in FIGS. 4A-4C upon leaving the end 50 of the cannula. Note, however, that an actuator sheath/member may be required to achieve certain catheter placement or trajectories as desired.
Use of the actuator also offers certain control over the control wire that may be desired from the perspective of user safety and ease of handling. Still, where a core wire is used alone, for most applications it will store less energy and, hence, present less of a threat than the above-referenced Nitinol needle/tube employed by Cook Medical.
Where no actuator member is provided though, it is still generally preferred to attach the guide wire used to a handle or grip in one way or another. This can facilitate pointing or directional input as with grip/stop 98 . Still, any wire used within catheter 70 may be directly manipulated (even by a loop or hook formed at the proximal end of the wire).
In addition, further variation is contemplated with respect to the end 100 of catheter 70 . Any number of tip configurations 102 may be employed. For instance, the variation in FIG. 9A includes a radiopaque marker 104 , such as a platinum band—the utility of which being well known to those with skill in the art. The variation in FIG. 9B includes a coring member 106 with a serrated edge 108 . Bone tissue may be cut free by twisting catheter 70 within cannula 42 , even relative to core wire 82 . Such action may be useful for traversing bone or obtaining a biopsy sample. For such purposes, the serrated member preferably comprises stainless steel or titanium alloy. It may also serve a function as a marker band for fluoroscopic visualization of the catheter tip.
Another option is to employ a perfusion/drainage tip 110 including a plurality of perforations or orifices 112 within the catheter wall or a terminal element attached thereto. Still further, especially for the removal of soft tissue, a foreceps or nibbler 114 type device may be provided at the end of the catheter. Such a device may operate by way of sliding a member 116 with resilient jaws 118 that ride back and forth over a restraining tube 118 , providing such action as indicated. Of course, other approaches as known in the art may be employed as well.
Another option for catheter 70 is to provide a modified fitting 74 at the proximal end of the device. Specifically, a dual input fitting 130 may be employed. In which case, a first orifice 132 could provide for receipt of the core wire 82 and/or actuator 72 while a second orifice 134 leading to a common lumen 136 may be used to introduce anything from flowable material to wire(s) or suture(s). Whether or not a multiple port fitting is provided, proximal fitting 74 may include wings 140 or similar structure to facilitate its angular manipulation.
Still further, an obturator may be used in connection with the present invention. A flexible member like obturator 140 shown in FIG. 11 may be employed to simply close-off catheter 70 upon removal of actuator 72 or core wire 82 .
Yet another option is to provide an obturator 142 as shown in FIG. 12 . This device comprises a rigid section 144 which may be tubular to receive a core wire and/or the distal end of actuator assembly 72 . The proximal end 146 of the obturator/perforator preferably comprises driving features 148 such as gears or a knurled interface. The features may be driven by hand or by an auxiliary device (not shown). The distal end 150 of obturator/perforator 142 comprises a plurality of interlocking links 152 . FIG. 13 shows a detail of the links. They are preferably regularly-shaped, repeating members (such as square or hexagonal segments) able to transmit torque applied to the drive futures to a working end 160 of the device.
The working end of the obturator may be configured in any number of manners. FIG. 14A is a close-up of a socket driver end 162 as seen in FIG. 13 . FIG. 14B shows a screw driver attachment 164 . FIG. 14C shows a cutter attachment in the form of a drilling, milling or grinding bit 166 . FIG. 14D shows a wire twister device 168 including a wire capture groove 170 . Other end configurations are possible as well.
In use, as alluded to above, the obturator may be over the actuator or a core wire. Alternately, it can be used within/guided by the catheter 70 alone upon removal of manipulator 72 or a mere core wire 82 . Generally, it is integrated with the handle (for example by gluing it within the interior of guide portion 94 ) as indicated by the dashed line placement of FIGS. 5A and 5B .
The possible constructional options of the various devices or device elements discussed above should be apparent to one with skill in the art. Generally, biocompatible materials including plastics, and metal alloys including steel, stainless steel and titanium alloys are preferred. This being said, catheter body 70 preferably comprises PEEK, actuator sheath 92 preferably comprises stainless steel or titanium/titanium alloy as do the various obturator components shown and discussed. The various handle members, and pressure applicator/injector may comprise nylon or another suitable material. Preferred guide/core wire composition has already been discussed.
In terms of sizing, the relative sizing of members is highly variable. However sized, certain members will be configured for navigating though harder tissues—particularly cancellous, cortical bone and cartilage. Variations in sizing are contemplated such that the present invention may be used for introducing surgical or diagnostics devices, fluids exhibiting a wide range of viscosities, pastes and powders. Notwithstanding, in a device developed for effecting vertebroplasty or long bone augmentation (as in the examples shown) suitable attributes are about as follow:
core wire 82 OD
0.5 to 1.6 mm
conduit 70 ID
1.2 to 3.7 mm.
conduit 70 OD
1.5 to 4.7 mm.
actuator sheath 92 ID
0.7 to 2.0 mm
actuator sheath 92 OD
0.8 to 2.5 mm
obturator 140/142 ID
0.9 to 2.8 mm
obturator 140/142 OD
1.2 to 3.7 mm
cannula 48 ID
1.5 to 4.7 mm.
cannula 48 OD
2.0 to 6.1 mm.
Wall thickness of the various members may, of course, be derived from the dimensions presented. The length of conduit 70 and actuator 72 /guide wire 82 may be set so as to reach sites distal of cannula end 50 by between about 0 and about 100 mm. An ability to reach sites between about 0 and 50 mm lateral of a cannula tip emplaced in cortical bone may be especially useful in vertebroplasty procedures Naturally, the particular configuration of the respective elements will vary according to the task that the hardware is applied. Of course, accessing a more remote location may be possible with the present invention as may any of the other applications noted and still others.
Though the invention has been described in reference to several examples, optionally incorporating various features, the invention is not to be limited to what is described or indicated as contemplated with respect to each variation. The breadth of the present invention is to be limited only by the literal or equitable scope of the following claims. That being said,
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Instruments and methodology for nonlinear access to bone tissue sites are described. Embodiments disclosed include a conduit for delivering material or a medical device to a site and a core member that is able to steer the conduit and allow the combination to be advanced thorough cancellous bone. A cannula and stylet may be provided to first advance through hard bone. The core member includes a curved tip that may be straightened by the cannula or an actuator sheath to vary sweep of the curve. An obturator may be included in the system. This instrument may include a flexible portion as well. Each of the obturator and conduit may be provided with any of a variety of active tips. The systems may be used to perform hard tissue site implantation, for example, in connection with a high pressure injection system.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a human sized manikin for the training of auscultation comprising a core body made of resin foam that has built-in speakers coupled to a living body sound reproducing apparatus and is covered by a fake skin or an imitation skin on the outside of the core body. This human sized manikin is used for the diagnostic training through auscultation in a medical education course and the like.
2. Description of Related Art
Those known as such kinds of human sized manikins are disclosed in Japanese Patent Application Examined Publication No. H05-27113 and Japanese Patent Publication No. 2990602.
These known techniques allow users to perform the diagnostic training through auscultation by reproduction of pre-recorded normal living body sounds and pre-recorded sounds from patients through small speakers built in sites to be auscultated.
However, when a stethoscope is displaced from the position of a speaker built in the manikin, subtle noise cannot be differentiated from others because propagation power of sounds in soft resin foam is very small. In addition, living body sounds are emitted with certain spreads depending on the positions of sound sources. For example, air cell sounds in lungs or lung sounds are categorized into those from the upper lung field, middle lung field, lower lung field, and bottom lung field, and each of them is also different in the right and left lungs. In addition, the former three sites require auscultation from both the front and back of the human body, so that each of these sounds needs to be auscultated separately. Furthermore, it is important in the training of auscultation to accurately obtain a range in which each sound spreads.
Therefore, the auscultation only at a pinpointed position is inconvenient for users to perform the natural and proper training of auscultation.
The problem to be solved in the present invention is to allow users to perform accurate auscultation of living body sounds at each site to be auscultated and obtain accurate auscultation ranges in a human sized manikin for training of auscultation comprising a core body made of resin foam that has built-in speakers coupled to a living body sound reproducing apparatus and is covered by an imitation skin on the outside of the core body.
SUMMARY OF INVENTION
Technical means to solve this technical problem is (i) forming recesses on a core body corresponding to sites to be auscultated; (ii) attaching a sound reflector with a concaved surface to the outside of each speaker; and (iii) fitting this speaker with a reflector in each recess and making the core body support each of the speakers separately.
The speaker coupled to a living body sound reproducing apparatus can diffuse the reproduced sounds because a sound reflector with concaved surface is attached to the outside of the speaker. Since this speaker with a reflector is fitted in each of the recesses formed corresponding to each site to be auscultated, it emits and spreads sounds outwardly. In addition, the core body supports the speakers separately and thus each of the sounds can accurately be differentiated from others.
Since the outside of the core body is covered with an imitation skin, the living body sounds reproduced are diffused between the reflector and the imitation skin. Therefore, the sounds can be auscultated accurately within certain ranges.
As for the living body sounds, it is sufficient that at least one or two kinds of sounds selected from the lung sounds, heart sounds, murmurs, and miscellaneous organic sounds are reproduced. In this case, besides a separate reproduction of each sound, synchronous reproductions of different kinds of sounds allows performing the various training of auscultation, including differentiation of a sound from combinations of different kinds of sounds or correlation thereof.
The size of the speaker and reflector is determined corresponding to each sound.
As for the lung sounds, as described in the beginning of this specification, auscultation needs to be performed on both the front and back of the body. For this purpose, a rotation axis is embedded and secured in the core body to support the manikin while allowed to rotate in the hoizontal direction, so that switch between the front and back for each auscultation can be obtained naturally.
When sounds are reproduced, digital signals need to be converted into analog signals. When a large number of sounds are reproduced at a time, sound quality may deteriorate because of the property of the D/A board. Then, when the living body sound reproducing apparatus can switch reproductions between the sounds for the front auscultation and those for the back auscultation at the rotation of the manikin, the number of the sounds reproduced at a time can be reduced. Thus the reproduction of the living body sounds can be performed without deterioration of sound quality.
The present invention has an advantage of allowing the proper training of auscultation corresponding to symptoms because accurate auscultation of living body sounds can be performed at each site to be auscultated and auscultation ranges can be obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation of a core body of a manikin in accordance with an exemplary embodiment of the present invention.
FIG. 2 is a left side elevation of the core body of the manikin.
FIG. 3 is a back elevation of the core body of the manikin.
FIG. 4 is a right side elevation of the core body of the manikin.
FIG. 5 is a cross section of a particularly part of the manikin.
FIG. 6 is a cross section of an exemplary embodiment of a pipe support of the manikin.
FIG. 7 is a bottom view of the pipe support having removed a bottom plate of a base.
FIG. 8 is a front elevation of a core body of a manikin in accordance with another exemplary embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 to 4 show a front elevation, left side elevation, back elevation, and right side elevation of a core body 2 for auscultation of the lung sounds. The left and light side elevations represent left and right sides of a human body, respectively. They are the reverses of the left and light sides seen toward the human body, respectively.
In FIG. 5, the manikin 1 has a core body 2 formed of urethane foam resin so as to have proper elasticity. This manikin is structured to have an imitation skin 3 with an inner cover 5 of urethane foam resin laminated the inside of an outer cover 4 formed of hard resin film such as vinyl chloride resin.
The core body and each cover can be formed of other materials as long as they have elasticity.
As mentioned below, recesses 15 for placement of speakers 11 are provided on the core body 2 . Providing the inner cover 5 prevents the positions of the recesses 15 from drawing attention when the manikin 1 is palpated.
Each speaker 11 , with each reflector 12 attached to its outside, is received in a supporting step part 16 provided at the bottom of the recess 15 . The speaker is supported in the recess 15 in a stable manner by engagement of the tip edge of the reflector 12 with engagement parts 17 formed around the opening edge of the recess 15 .
In the inner cover 5 , a plurality of small holes 6 are opened at the positions corresponding to the recesses 15 so that the inner cover 5 does not cut off the sounds from the speaker 11 . The sounds to be reproduced are diffused by the reflector 12 , through the pass holes 6 in the inner cover 5 , and then auscultated via the outer cover 4 (see FIG. 5 ).
Desirably, the reflector 12 is shaped to conform to the spread of each site to be auscultated. The reflector can be formed of such materials as hard plastic, metal, wood, and cardboard.
In the front of the core body 2 , the recesses 15 are formed at respective positions of the respiratory system (a), upper lung field right (b), middle lung field right (c), lower lung field right (d), upper lung field left (e), middle lung field left (f) and lower lung field left (g) (see FIG. 1 ). In the back, the recesses 15 are formed at respective positions of the upper lung field left (j), middle lung field; left (k), lower lung field left (l), upper lung field right (m), middle lung field right (n) and lower lung field right (o) (see FIG. 3 ). In the left side of the body, a recess is formed at the position of the bottom lung field left (h), while in the right side of the body, at the position of the bottom lung field right (I) (see FIGS. 2 and 4 ).
At the bottom of each recess 15 , a small hole 7 is provided to a guide lead 13 for the speaker 11 and pass all of the leads 13 through the inside of the core body 2 .
In this embodiment, a pipe 21 as a rotation axis is embedded vertically in the center and inside of the core body 2 so that an actual medical examination can be performed. In addition, as described below, the pipe is supported by a base 23 so that the lower part of the pipe 21 can be rotated.
Through the cylindrical wall of the pipe 21 , holes 22 are provided corresponding to the position of each hole 7 in communication with each recess 15 , and the leads 13 are coupled to a living body sound reproducing apparatus (not shown) through the inside of the pipe 21 .
The base 23 to support the lower part of the pipe 21 to which the manikin 1 is secured has a cavity formed therein. The lower part of the pipe 21 is inserted into a supporting hole 25 formed in the center of a top plate 24 and the bottom end of the pipe is brought into contact with a bottom plate 26 to support the pipe 21 allowing its rotation.
A limit switch 27 is secured to the inside of the base 23 , and the lower part of the pipe 21 has a projection 28 to activate this switch. (In the embodiment shown in FIG. 7, a bolt is used as the projection.) The switch 27 is opened/closed by rotating the manikin 1 to allow sounds reproduction from the living body sound reproducing apparatus (not shown) to be switched between the sounds for auscultation of the front body shown in FIG. 1 and those of the back body shown in FIG. 3 .
In the bottom edge of the supporting hole 25 , steps 29 to come into contact with the projection 28 are formed so that the manikin 1 reciprocatively rotates in a range of 180°, and thereby the limit switch and the sound reproduction can be always switched simultaneously.
As a supporting structure of the pipe 21 , other construction can be used. A living body sound reproducing apparatus able to reproduce the sounds from the front and back of the body at the same time does not require such a sound switching device and a controlled rotation range of the manikin 1 above described.
FIG. 8 shows a front of a core body 2 used in a manikin for auscultation of the pulsation and beat sounds or heart sounds. The core body 2 has small recesses at an aortic valve site 31 , a pulmonary valve site 32 , a tricuspid valve site 33 , a mitral valve site 34 and a carotid artery site 35 . A small speaker (not shown) with a circumferential reflector is attached to each of the recesses.
The core body can also be structured as a combination of recesses shown in FIGS. 1 and 8 so that the respiratory system, air cell, artery, beat sounds, and miscellaneous organic sounds can be auscultated at the same time.
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A human sized manikin for the training of auscultation comprising a core body formed of resin foam that has speakers coupled to a living body sound reproducing apparatus and is covered by an imitation skin on the outside of the core body. Recesses are formed on the core body corresponding to sites to be auscultated, a sound reflector with a concaved surface is attached to the outside of each speaker, and this speaker with a reflector is fitted in each recess and supported by the core separately.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of U.S. patent application Ser. No. 10/785,892, entitled “Gas Drive Electrolytic Cell”, filed on Feb. 23, 2004, which application is a continuation-in-part of U.S. patent application Ser. No. 09/907,092, entitled “Portable Water Disinfection System,” filed on Jul. 16, 2001, now issued as U.S. Pat. No. 6,736,966, and which claims priority to U.S. Patent Application Ser. No. 60/448,994 entitled “Electrolytic Cell for Surface and Point of Use Disinfection”, filed Feb. 21, 2003. This application is also related to U.S. patent application Ser. No. 10/785,610, entitled “Electrolytic Cell for Surface and Point of Use Disinfection”, filed Feb. 23, 2004. The specifications and claims of all applications listed are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to an electrolytic cell producing oxidants that operates in batch mode and utilizes gas pressure generated within the cell to transfer the contents from the electrolytic cell.
BACKGROUND OF THE INVENTION
[0003] Electrolytic technology utilizing dimensionally stable anodes (DSA) has been used for years for the production of chlorine and other mixed-oxidant solutions. Dimensionally stable anodes are described in U.S. Pat. No. 3,234,110 to Beer, entitled “Electrode and Method of Making Same,” whereby a noble metal coating is applied over a titanium substrate.
[0004] An example of an electrolytic cell with membranes is described in U.S. Patent RE 32,077 to deNora, et al., entitled “Electrode Cell with Membrane and Method for Making Same,” whereby a circular dimensionally stable anode is utilized with a membrane wrapped around the anode, and a cathode concentrically located around the anode/membrane assembly.
[0005] An electrolytic cell with dimensionally stable anodes without membranes is described in U.S. Pat. No. 4,761,208 to Gram, et al., entitled “Electrolytic Method and Cell for Sterilizing Water.”
[0006] Commercial electrolytic cells have been used routinely for oxidant production that utilizes a flow-through configuration that may or may not be under pressure that is adequate to create flow through the electrolytic device. Examples of cells of this configuration are described in U.S. Pat. No. 6,309,523 to Prasnikar, et al., entitled “Electrode and Electrolytic Cell Containing Same,” and U.S. Pat. No. 5,385,711 to Baker, et al., entitled “Electrolytic Cell for Generating Sterilization Solutions Having Increased Ozone Content,” and many other membrane-type cells.
[0007] In other configurations, the oxidant is produced in an open-type cell or drawn into the cell with a syringe or pump-type device, such as described in U.S. Pat. No. 6,524,475 to Herrington, et al., entitled “Portable Water Disinfection System.”
[0008] U.S. patent application Ser. No. 09/907,092 to Herrington, et al., entitled “Portable Water Disinfection System,” the specification of which is incorporated herein by reference, describes disinfection devices that utilize, in one instance, a cell chamber whereby hydrogen gas is generated during electrolysis of an electrolyte, and provides the driving force to expel oxidant from the cell chamber through restrictive check valve type devices. In this configuration, unconverted electrolyte is also expelled from the body of the cell as hydrogen gas is generated. In an alternate configuration in the same application, hydrogen gas pressure is contained in a cell chamber during electrolysis, but the pressure within the cell chamber is limited by the action of a spring loaded piston that continues to increase the volume of the cell chamber as gas volume increases. Ultimately, a valve mechanism opens, and the spring-loaded piston fills the complete volume of the cell chamber forcing the oxidant out of the cell chamber.
[0009] In the current embodiment of the present invention, the cell chamber incorporates an inactive gas chamber at the top of the cell that allows the accumulation of gas (e.g. hydrogen gas). The gas pressure is generated, and this pressure is ultimately utilized as the sole driving force to expel the oxidant from the bottom of the cell through a valve mechanism. Utilizing this mechanism, complete electrolytic conversion of the electrolyte in the cell chamber is achieved allowing optimal operational efficiency.
[0010] Other inventions that utilize gas pressure generated from electrolysis are also described in the literature. U.S. Pat. No. 4,138,210, to Avedissian, entitled “Controlling the Pressure of a Gas Generator,” describes a gas torch that utilizes an electrolytic mechanism for generating and controlling pressure of hydrogen gas that is used as the feed gas for the torch. U.S. Pat. 5,221,451 to Seneff, et al., entitled “Automatic Chlorinating Apparatus,” describes a chlorine gas generating cell that operates at the same pressure as the treated water flow stream. Water under pressure flows through the closed cell and replenishes the electrolyte level in the cell. Partitions within the electrolytic cell maintain separation of the chlorine gas that is aspirated in the water stream. Chlorine and hydrogen gas generated within the cell maintain a pressure balance between the chlorine gas phase and the pressure of the liquid water flowing through the cell so that unconverted electrolyte is not drawn into the flowing water stream. U.S. Pat. No. 5,354,264 to Bae, et al., entitled “Gas Pressure Driven Infusion System by Hydrogel Electrolysis,” describes a system that generates and controls the production of oxygen and hydrogen gas in an electrolytic hydrogel process for the purpose of closely regulating the amount of liquid drugs that are delivered under gas pressure to the human body.
BRIEF SUMMARY OF THE INVENTION
[0011] The preferred embodiment of the present invention is an apparatus to produce a disinfecting solution to treat a fluid. The apparatus comprises at least one cell. The cell comprises at least two electrodes wherein at least one electrode comprises at least one cathode and at least one electrode comprises at least one anode. The apparatus comprises a control circuit for providing an electrical potential between at least one cathode and at least one anode, wherein the control circuit is in electrical contact with at least one cathode and at least one anode.
[0012] During generation of oxidants, electrolyte is located within the cell housing between the anode and cathode, and a controlled electrical charge passes through the electrolytic solution from at least one cathode and at least one anode, thereby generating at least one oxidant in the electrolyte. An energy source in electrical contact with the control circuit delivers a controlled electrical charge having a predetermined charge value.
[0013] A headspace in the electrolytic cell accumulates generated gas under pressure for the purpose of utilizing the generated gas pressure to expel the contents of the cell on completion of electrolysis.
[0014] Prior to electrolysis, electrolyte is introduced into the cell via an inlet port. The inlet port comprises an inlet port mechanism such as a valve to seal the inlet port after the electrolyte has entered the cell. The cell further comprises an outlet port and outlet port mechanism such as a valve to seal the outlet port during electrolysis. After electrolysis, the outlet port mechanism opens and allows discharge of electrolyzed oxidant through the outlet port.
[0015] In the preferred embodiment, the apparatus comprises a positive displacement pump for transfer of the electrolyte to an interior of the cell. In an alternative embodiment, the inlet port mechanism comprises a control valve to allow transfer of electrolyte to the interior of the cell. In another embodiment of the present invention, the inlet port mechanism comprises a dual control valve to allow transfer of electrolyte to the interior of the cell while simultaneously allowing gas to vent out of the cell. Prior to electrolysis during the fill operation, gas venting, depending on system design, may be required in order to allow electrolyte to flow to the interior of the cell without restriction from gas pressure buildup in the confined space within the cell.
[0016] In another embodiment of the present invention, the inlet port mechanism comprises a check valve to allow transfer of electrolyte to the interior of the cell. During electrolysis the check valve restricts flow of gas and fluids out of the cell.
[0017] The apparatus of the present invention comprises an electrolyte storage container. The electrolyte storage container may be a permanent part of the apparatus, or it may be a replaceable electrolyte storage container. To allow free flow of electrolyte solution from the electrolyte storage container, the container comprises a vent valve to release negative pressure from within the electrolyte storage container to allow free flow of electrolyte from the container. In the preferred embodiment, the electrolyte storage container comprises a quick disconnect valve on the container discharge port to allow removal of the container from the system without loss of electrolyte from the container. In an alternative embodiment, the electrolyte storage container is collapsible.
[0018] In an alternative embodiment of the present invention, the apparatus comprises a microprocessor circuit that identifies the electrolyte storage container with system. The remaining contents of the electrolyte storage container can be determined by virtue of the microprocessor by keeping track of the number of operations of the apparatus, and knowing the volume of electrolyte used during each operational cycle.
[0019] The apparatus further comprises a fluid storage container for storage of a fluid to be treated by the oxidant solution. In the preferred embodiment, the fluid storage container comprises an oxidant measuring device. In the preferred embodiment, the oxidant measuring device is a chlorine measuring device. In an alternative embodiment of the present invention, the chlorine measuring device is a solid-state semiconductor commonly referred to as a “sensor-on-a-chip”. In a further embodiment of the present invention, the oxidant measuring device comprises an oxidation reduction potential (ORP) measuring device. To ensure accuracy of the ORP measuring device, the oxidant sensor may also comprise a device for measuring temperature and pH and adjusting the ORP value for variations in temperature and pH.
[0020] In an alternative embodiment of the present invention, the apparatus comprises an oxidant storage container in lieu of a fluid storage container. Alternately, the apparatus comprises a port for injection of oxidants directly into a selected source to be treated. The source to be treated my be a closed fluid body such as a water tank, open fluid body such as a swimming pool, a pipe with fluid flowing therein, a sump such as in a cooling tower, a basin, trough, and/or a plenum for spraying oxidant into a gas stream such as an air duct or other gas stream for oxidizing constituents in the gas stream.
[0021] The apparatus of the present invention further preferably comprises a microprocessor control system. The control system measures and controls power to the anode and cathode, controls activation of the inlet port feed mechanism, the outlet port mechanism, and the oxidant measuring device. Further, the apparatus comprises an electrolyte storage container microprocessor for identifying the electrolyte storage container with the system. The electrolyte storage container microprocessor maintains a record of a number of electrolytic cycles associated with the electrolyte storage container for the purpose of determining the remaining volume and remaining number of cycles available in the electrolyte storage container. By this means, the electrolyte storage container can be removed from the system and replaced by an alternate electrolyte storage container. Data recorded in the microprocessor allows the control system of the apparatus to keep track of the remaining electrolyte in each unique electrolyte storage container.
[0022] Broadly, it is a primary object of the present invention to provide a batch mode electrolytic cell that utilizes a gas chamber space above the electrodes within a confined cell. During electrolysis, gases, primarily hydrogen gas, are utilized to expel the generated oxidant from the electrolytic cell via a cell discharge valve to a fluid to be treated, or an oxidant storage container.
[0023] A primary advantage of the present invention is that a simple gas chamber space above the electrodes within an electrolytic cell is utilized to provide the driving force to expel oxidant from the electrolytic cell to a fluid to be treated. This configuration allows complete electrolysis of the electrolyte for efficient operation, and does not rely on a flow-through cell or separate pumping devices to transfer the oxidant to the fluid to be treated. Gas pressure generated in the electrolysis process is utilized to provide the force to transfer oxidant from the cell. This configuration allows for very low cost manufacturing for applications in consumer devices, or other low fluid volume systems.
[0024] Other objects, advantages and novel features, and further scope of applicability of the present invention will be set forth in part in the detailed description to follow, taken in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0025] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate several embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are only for the purpose of illustrating a preferred embodiment of the invention and are not to be construed as limiting the invention. In the drawings:
[0026] FIG. 1 is a view of an electrolytic cell with a gas chamber space above the electrodes;
[0027] FIG. 2 is a system configuration utilizing a pump to transfer electrolyte to an electrolytic cell with a gas chamber;
[0028] FIG. 3 is a system configuration utilizing gravity to transfer electrolyte to an electrolytic cell with a gas chamber; and
[0029] FIG. 4 is a system configuration utilizing gravity to transfer electrolyte to an electrolytic cell with a gas chamber and a dual valve mechanism to vent the cell chamber during fill.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The present invention comprises an electrolytic cell and method for generation of oxidants that are utilized to disinfect surfaces, liquids, or airborne contaminants.
[0031] Referring to FIG. 1 , which shows the preferred embodiment of the invention, electrolyte solution 14 , preferably, a sodium chloride brine solution is introduced into cell housing 12 which comprises positive anode 17 and negative cathode 18 wherein electrolyte solution 14 is electrolytically converted to an oxidant solution within the confined space of electrolytic cell 10 . Any electrolyte solution for generating an oxidant is useful in accordance with the present invention.
[0032] During electrolysis, hydrogen gas is liberated at cathode 18 and accumulates in headspace 13 . As hydrogen gas accumulates in headspace 13 , gas pressure increases according to the well known gas equation, PV=nRT wherein P is the pressure of the gas, V is the volume of the chamber, n is the moles of gas, R is the molar gas constant, and T is the absolute temperature. Gas pressure increases by virtue of the fact that inlet valve 15 and outlet valve 16 are both closed.
[0033] To initiate the process, outlet valve 16 is closed and inlet valve 15 is open. Electrolyte solution 14 is introduced to cell housing 12 either by gravity feed or by utilizing a fluid transfer device such as a pump to introduce the electrolyte solution 14 to interior of the cell housing 12 .
[0034] After electrolyte solution 14 has been introduced into cell housing 12 , inlet valve 15 is closed, and electrical power is applied across the positive electrode, anode 17 , and negative electrode, cathode 18 . Anode 17 and cathode 18 are sealed within cell housing 12 .
[0035] During electrolysis, hydrogen gas is generated at the surface of cathode 18 . The hydrogen gas bubbles rise and accumulate in headspace 13 . As electrolysis continues, gas pressure within headspace 13 rises creating a pressure within cell housing 12 . With proper design, approximately all of the sodium chloride within electrolyte solution 14 is efficiently converted to oxidant.
[0036] The volume of headspace 13 determines the pressure that is built up within cell housing 12 . The appropriate pressure desired is a function of the system design and the required pressure needed to discharge the oxidant contents within cell housing 12 to the oxidant storage device, or preferably, the fluid to be treated. The fluid to be treated may be at zero pressure, or any other pressure such as the pressure in a normal water supply system.
[0037] Oxidant produced from the electrolysis of electrolyte solution 14 is discharged from cell housing 12 by opening outlet valve 16 . Most of the hydrogen gas generated in the electrolysis process is also discharged from cell housing 12 through outlet valve 16 . Efficient production of oxidant can be generated in a series of batch process sequences previously described, and can utilize the gas pressure generated in the electrolysis process to provide the force necessary to introduce the oxidant to the fluid to be treated, without the need for auxiliary pumps or transfer devices.
[0038] The preferred embodiment of the system of the present invention is shown in FIG. 2 . In the preferred embodiment, electrolytic cell 10 receives electrolyte solution 14 from an electrolyte storage container 38 . Electrolysis occurs within cell 10 and the resulting oxidant solution is then transferred to fluid 46 to be treated within fluid storage device 44 which may or may not be under pressure.
[0039] In the preferred embodiment, electrolyte storage container 38 is removable for subsequent replacement by new electrolyte storage container 38 . Electrolyte storage container 38 comprises vent valve 42 that allows the introduction of air into electrolyte storage container 38 as electrolyte solution 40 is drawn out of container 38 thereby avoiding negative pressure in container 38 . Electrolyte storage container 38 can be quickly removed from the system by means of quick disconnect self-sealing valve 36 .
[0040] In an alternative embodiment of the present invention, container 38 comprises a microchip device that identifies container 38 with the total system, and provides for electronic monitoring of the volume of the contents of container 38 based on the number of cycles of the system.
[0041] In another embodiment of the present invention, electrolyte storage container 38 can be replaced with a brine generating device. A brine generating device is filled with salt, preferably a halogen salt, and water mixes with the halogen salt to produce a liquid brine solution. The liquid brine solution performs as electrolyte 40 .
[0042] In the preferred embodiment, electrolyte 40 is transferred to electrolytic cell 10 by a positive displacement pump such as diaphragm type pump 30 with inlet valve 32 and outlet valve 34 integral with the pump head. As previously described, electrolysis of the electrolyte solution occurs within cell 10 thereby converting electrolyte solution 14 to disinfecting oxidants. With proper sizing of cell 10 , the concentration of electrolyte 14 , and the amount and duration of electrical power applied to electrolyte 14 within cell 10 , very efficient conversion of electrolyte 14 is facilitated.
[0043] Concurrent with production of oxidants, gas is generated within headspace 13 thereby developing pressure. Upon completion of electrolysis, discharge valve 16 is opened allowing the discharge of oxidant to fluid storage container 44 .
[0044] In the preferred embodiment, outlet valve 16 is preferably a solenoid valve. The fluid to be treated is held in container 48 . This may be a water storage tank. Alternate embodiments include a container that holds a fluid to be treated that can be used to disinfect surfaces, for instance, a spray bottle.
[0045] In the preferred embodiment, the system is controlled by microprocessor 50 . In the preferred embodiment, the system is a batch process that maintains a residual oxidant value, preferable a chlorine residual value, in fluid storage container 44 . Fluid storage container 44 comprises an oxidant residual monitoring device, preferably chlorine sensor 48 .
[0046] In an alternative embodiment, the oxidant residual monitoring device comprises an oxidation reduction potential (ORP) sensor or chlorine sensor mounted on an integrated circuit device (aka chlorine sensor-on-a-chip).
[0047] In the preferred embodiment, the fluid level in fluid storage container 44 is not important to maintaining the desired oxidant residual value. Chlorine sensor 48 monitors the chlorine residual value via microprocessor 50 . If the chlorine residual value is below the desired value, microprocessor 50 instructs the system to produce another batch of oxidant in cell 10 . In this mode of operation, neither the oxidant demand of the fluid to be treated, nor the volume of fluid in the fluid storage container 44 are important to maintaining the desired chlorine residual value. If the chlorine residual value is not sufficient, microprocessor 50 continues making oxidant in batches until the desired chlorine residual is maintained.
[0048] In an alternative embodiment shown in FIG. 3 , the electrolyte is transferred by gravity via inlet solenoid valve 60 instead of fluid transfer pump 30 shown in FIG. 2 . The operational scenario with inlet solenoid valve 60 works well if fluid transfer line sizes are adequately sized to avoid flow resistance due to electrolyte fluid viscous effects or hydraulic locking that avoids transfer of vent gasses in the fluid transfer lines.
[0049] In an alternative embodiment of the present invention, inlet solenoid valve 60 is replaced with a simple check valve. With proper timing via microprocessor 50 , the batch process is terminated by removing power from anode 17 and cathode 18 and opening outlet solenoid valve 16 . As the contents of cell 10 are discharged, outlet solenoid valve 16 can remain open long enough for electrolyte 40 to flow into cell 10 , and then outlet solenoid valve 16 is closed. Electrolyte flows through the inlet check valve and the check valve will close after electrolyte 40 has entered cell 10 . The inlet check valve prevents the flow of gas from moving backwards up to electrolyte storage container 38 .
[0050] In an alternative embodiment shown in FIG. 4 , the electrolyte is transferred by gravity via dual inlet valve 70 and 72 which also incorporates a vent line to relieve pressure within electrolytic cell 10 allowing free flow of electrolyte 40 into cell 10 .
[0051] Applications of the present invention are especially applicable to low-cost water treatment systems for the home-use and consumer market. However, it will be obvious to those versed in the art that this invention can be utilized in a variety of applications including spray bottle applications for surface cleaning, potable water treatment systems, wastewater treatment systems, swimming pool treatment systems, cooling tower treatment systems, and other applications where a disinfectant is utilized to treat a fluid.
[0052] Although the invention has been described in detail with particular reference to these preferred embodiments, other embodiments can achieve the same results. Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover in the appended claims all such modifications and equivalents. The entire disclosures of all references, applications, patents, and publications cited above are hereby incorporated by reference.
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The present invention is directed to an electrolytic cell that is completely sealed during the electrolysis operation during production of oxidant. Gasses generated within the electrolysis operation, primarily hydrogen that is liberated at the cathode surface, increase the pressure within the cell, and the gas pressure is ultimately utilized to expel the oxidant from the cell chamber.
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This application is a continuation of application Ser. No. 07/858,609, filed Mar. 27, 1992, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor nonvolatile RAM, and, more specifically, to a chip on which both a DRAM (dynamic random access memory) as a RAM (random access memory), and an E 2 PROM (electrical erasable read only memory) as a nonvolatile memory are arranged.
2. Description of the Related Art
FIG. 12 is a diagram showing a cross section of a conventional nonvolatile RAM in which a DRAM cell and an E 2 PROM cell are mixedly arranged, and FIG. 13 shows an equivalent circuit of this conventional RAM.
A transistor T1, which is turned ON/OFF by a potential of a select gate SG corresponding to a word line, serves to selectively connect a drain D (n + ) corresponding to a bit line and a memory node NP of the DRAM cell with each other. A transistor T2 serves to connect the transistor T1 and a transistor T3, which is a part of the E 2 PROM cell, together.
A capacitor of the DRAM cell includes a memory node NP connected to a source of the transistor T1, and a control gate CG. The control gate CG serves as a plate electrode, and is controlled by means of a pulse in a store mode for transferring data from the DRAM cell to the E 2 PROM cell, and in the recall mode for transferring data from the E 2 PROM cell to the DRAM cell.
A nonvolatile RAM having the above-described structure, when operated as a regular DRAM, serves as a stack-type cell. In other words, both a recall gate RG and the control gate CG of the transistor T2 are grounded so that the control gate CG serve as a plate electrode, and the storage capacitor of the DRAM is the capacity between the control gate CG and the memory node NP. Since the recall gate RG is ground, the DRAM and E 2 PROM cells are separated from each other. The basic operation of the DRAM, including writing, reading-out, refreshing, etc. is the same as that of regular DRAM cells.
The following is an explanation of the operation of the store mode for transferring data stored in the DRAM cell to the E 2 PROM cell.
As can be seen in FIG. 14, the operation of the store mode can be divided into two, the first half and the last half.
The first half of the operation is an erasing process which writes the data of the DRAM cell, which stores data "0", in the E 2 PROM cell. Electrons are emitted from the floating gate FG of the corresponding E 2 PROM cell. As shown in the FIG. 14, the control gate CG and the source S are biased to the potentials of the ground and the power source Vp, respectively. Between the control gate CG and the source S, provided are the memory node NP serving as a floating node and the floating gate FG, which are capacitive-coupled with each other between the ground potential and the power source Vp.
When data "0" is stored in the DRAM cell, the memory capacitor between the control gate CG and the memory node NP is not charged, whereas when data "1" is stored therein, the storage capacitor is charged with "+" electrical charges. Consequently, while the control gate CG and the source S are biassed to the ground potential and the power source voltage Vp, respectively, a weak electrical field is applied onto the thin tunnel oxidation film located between the floating gate FG and the source S in the E 2 PROM cell, when data "1" is stored in the DRAM cell. In contrast, under the same condition, the intensity of the electrical filed applied to the thin tunnel oxidation film in the DRAM cell, when data "0" is stored, is high. Therefore, only in the latter case, an F-N (Fowler-Nordheim) current flows in the E 2 PROM, and electrons are discharged from the floating gate FG.
The last half of the store mode is a programming process in which electrons are injected to the floating gate of the E 2 PROM cell so as to write data of the DRAM cell storing data "1" into the E 2 PROM. As can be understood from FIG. 14, the control gate CG and the source S are biassed to the power source voltage Vp and the ground potential, respectively, and therefore the electrical field applied onto the tunnel oxidation film provided between the floating gate FG and the source S is weak in the case of DRAM "0" and strong in the case of DRAM "1". Thus, only in the latter case, an F-N current flows through the E 2 PROM cell in the direction opposite to that of the erasing process, and electrons are injected to the floating gate FG for programming.
The following is an explanation of the recall mode for transferring data stored in the E 2 PROM cell to the DRAM cell with reference to FIG. 15.
First, a drain D=5V and a select gate SG=8V are set, and data "1" is written in every DRAM cell. Then, a recall gate RG is set to 8V. At the recall gate RG=8V, the threshold level of the transistor in the E 2 PROM, when data "0" is stored therein, is low, and therefore the transistor is set in a depletion mode, whereas that of the E 2 PROM, when data "1" is stored therein, is high, and therefore the transistor is set in an enhance mode. Accordingly, electrical charges accumulated in the DRAM cell connected to the E 2 PROM cell, when data "0" is stored therein, are discharged to the source terminal of the E 2 PROM through the transistors T2 and T3, turned on by the recall gate RG. In contrast, charges in the DRAM cell connected to the E 2 PROM cell, when data "1" is stored therein, remain in the DRAM cell without being discharged. Consequently, data stored in the E 2 PROM is thus transferred to the DRAM cell.
In the meantime, conventional nonvolatile RAM cells are those which consist of DRAM cells and E 2 PROM cells effectively mixed thereon. However, these cells have a structure in which three transistors T1, T2, and T3 are arranged in the same plane, as can be seen in FIG. 12. As a result, the occupied area in a cell is significantly larger than that of a regular DRAM or E 2 PROM.
SUMMARY OF THE INVENTION
The present invention has been proposed in consideration of the above problem, and the object thereof is to provide a semiconductor nonvolatile RAM in which a DRAM cell and an E 2 PROM cell are effectively arranged, and the occupied area is about the same as that of a regular DRAM cell or an E 2 PROM cell.
The object of the invention can be achieved by:
a semiconductor nonvolatile RAM comprising:
a dynamic RAM cell having a first transistor one end of a current path of which is connected to a bit line, and a gate of which is connected to a word line, and a storage region connected to an other end of the current path of the first transistor, for storing data; and
an E 2 PROM cell having a second transistor including a floating gate and a control gate, one end of a current path of the second transistor including a channel region connected to the other end of said first transistor, a part of said channel region of said second transistor is rendered conductive in accordance with data stored in the storage region of the dynamic RAM cell.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate a presently preferred embodiment of the invention, and together with the general description given above and the detailed description of the preferred embodiment given below, serve to explain the principles of the invention.
FIG. 1 is a side cross section of the first embodiment of the present invention;
FIG. 2 is a diagram showing an circuit equivalent to the embodiment shown in FIG. 1;
FIGS. 3A, 3B, 4A, and 4B are diagrams illustrating erasing and programming operations of the cell shown in FIGS. 1 and 2;
FIG. 5 is a diagram showing waveforms during the erasing and programming operations;
FIGS. 6 and 7 are diagrams illustrating both DRAM "0" and DRAM "1" cases of recall operations of the cell shown in FIGS. 1 or 2;
FIG. 8 is a diagram showing waveforms during the recall operations of the cell shown in FIGS. 1 or 2;
FIG. 9 is a diagram of an equivalent circuit of the cell showing in FIGS. 1 or 2, designed to explain the function thereof as a DRAM;
FIG. 10 is a pattern plan view of the main portion of a conventional semiconductor nonvolatile RAM;
FIG. 11 is a pattern plan view of the main portion of a semiconductor nonvolatile RAM according to the present invention;
FIG. 12 is a side cross section of a conventional semiconductor nonvolatile RAM;
FIG. 13 is a diagram showing a circuit equivalent to the conventional RAM shown in FIG. 12;
FIG. 14 is a diagram showing waveforms during erasing and programming operations of the RAM shown in FIGS. 12 or 13; and
FIG. 15 is a diagram showing waveforms to explain recall operations of the RAM shown in FIGS. 12 or 13.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the present invention will now be explained in detail with reference to accompanying drawings.
FIG. 1 is a cross section of a structure of the present invention, and FIG. 2 is a circuit diagram equivalent to the structure shown in FIG. 1. In FIGS. 1 and 2, the same items are designated by the same numerals.
Inside a semiconductor substrate 1, an n + diffusion layer serving as a drain D and source S, constituting an access transistor T1 of a DRAM cell, and another n + diffusion layer serving as a source, which is a part of transistor T2 of an E 2 PROM cell, are arranged a predetermined distance away from each other. The n + diffusion layer serving as the source of the transistor T1, a part of the DRAM cell, also plays the role of a drain D of the transistor T2 constituting the E 2 PROM cell.
A select gate SG of the access transistor T1 is provided above the semiconductor substrate 1 such as to be insulated therefrom, and this select gate SG is connected to a word line WL as shown in FIG. 2. Meanwhile, the drain D of the access transistor T1 is connected to a bit line BL. Further, a storage capacitor of the access transistor T1 is formed of a storage node NP connected to the source S of the transistor T1, and a control gate CG provided as a plate electrode above the storage node NP such as to be insulated therefrom.
In the E 2 PROM cell, there is provided a thin tunnel oxidation film TO on the source S of the transistor T2, and a floating gate FG on this tunnel oxidation film TO. On this floating gate FG, is an insulating layer, on which the storage node NP of the DRAM cell is further provided. On this storage node NP, is another insulating layer, on which the control gate CG is further formed. On this control gate CG, is another insulating layer, on which the above-mentioned bit line BL is formed.
In the meantime, a part of the above-mentioned floating gate FG projects out above the mid portion between the source and drain of the transistor T2. The storage node NP includes a gate portion NP1 which does not overlap the floating gate FG and acts as a gate of the transistor 2. This gate portion NP1 is located above the mid-portion of the source and drain of the transistor T2, and the distance from the surface of the semiconductor substrate 1 to the gate portion NP1 is the same as the length of the projecting portion FG1 of the floating gate FG. Between the gate portion NP1 and the semiconductor substrate 1, and between the projecting portion FG1 of the floating gate FG and the semiconductor substrate 1, are insulating layers. With a channel CH provided between the source and drain of the transistor T2, the portion controlled by the projecting portion FG1 of the floating gate FG, and the portion controlled by the gate portion NP1 of the storage node NP, can be continuously formed in a self-aligned manner. Consequently, a coupling capacitor between the floating gate FG and the storage node NP can be made large, and the occupied area in the cell can be reduced at the same time.
The following is an explanation of the operation of the cell having the above-described structure with reference to FIGS. 3 through 5.
As mentioned before, the operation of a nonvolatile RAM is divided into three modes, i.e. a store mode for writing data stored in the DRAM cell to the E 2 PROM cell by transfer, a recall mode for transferring data stored in the E 2 PROM cell to the DRAM cell, and a regular operation as a DRAM.
Transfer of data stored in the DRAM cell to the E 2 PROM cell is in fact an erasing operation in which electrons are emitted from the floating gate of the E 2 PROM cell in accordance with data "1" or "0" stored in the DRAM cell, or a programming operation in which electrons are injected into the floating gate FG. In the cell according to an embodiment of the present invention, data stored in the DRAM cell is transferred to the E 2 PROM by the following operation.
First, data stored in the DRAM cell is read out to a bit line BL. In other words, the bit line BL is initialized to the initial voltage, and a group of cells is selected by a select gate SG. Thus, a small signal is read out to the bit line from the selected cell. This read out small signal is amplified by a sense-amplifier, which is not shown.
After that, the select gate SG is closed, and the control gate is set to a high potential, for example, 12V (this high potential will be called Vp hereinafter). The source S of the transistor T2, which has been maintained at a power source voltage Vcc (5V) up until then, is lowered to a ground potential. Such a status is illustrated in FIG. 3A. In this status, the control gate CG is set to the high potential Vp; therefore the potential of the storage node NP which is capacity-coupled with the control gate CG is also raised, and so is the potential of the floating gate FG capacity-coupled with the memory node NP.
On the other hand, since the source S of the transistor T2 is grounded, an electrical field is created in the tunnel oxidation film TO in the direction of injection of electrons from the source S to the floating gate FG. It should be noted here that in the case where data "0" is stored, i.e. no charges are accumulated in the storage node NP, electrons are injected into the floating gate FG in advance as can be seen in FIG. 3A. Accordingly, in the case where data "1" is stored in the cell as shown in FIG. 3B, the electrical field acting on the tunnel oxidation film TO is further intensified, compared to the case where data "0" is stored. However, the transistor T2 of the E 2 PROM cell is turned on so as to discharge the charges accumulated in the storage node NP to the source S as indicated by broken lines. Thus, as in the case where data "0" is stored in the E 2 PROM cell, electrons are injected to the floating gate FG. That is, at the initial stage of the store mode, regardless of data "1" or "0" stored in the DRAM cell, electrons are injected to the floating gate FG, and thus programming is carried out.
Next, the data read out to the bit line BL from the DRAM cell is written back to the DRAM cell. Consequently, electrons are erased from only cells in which data "0" is stored. More specifically, as shown in FIG. 5, after setting the source S of the transistor T2 and the control gate CG back to the potential Vcc and the ground potential GND, respectively, the select gate SG is opened. In other words, the data read out to the bit line BL from the DRAM cell is written back to the DRAM cell. Then, the source S of the transistor T2 is set to a high voltage Vp so as to apply a strong electrical field in the electron-emitting direction onto the tunnel oxidation film TO of the E 2 PROM cell in which no charges are accumulated in the storage node NP, i.e. data "0" is stored, as shown in FIG. 4A. Further, as can be seen in FIG. 4B, in the DRAM cell in which data "1" is stored, positive charges are accumulated between the storage node NP and the control gate CG; therefore an electrical field acting on the tunnel oxidation film TO is so weak that no electrons are emitted. Here, in the cell in which data "0" is stored, since the channel portion having the gate portion NP1 of the storage node NP as its gate is cut off, no electrons flow from the source S to which the high potential Vp is applied, to the storage node NP. Eventually, in the cell storing data "0", since no electrons are caught in the floating gate FG, the threshold level of the transistor T2 of the E 2 PROM cell becomes low, whereas in the cell storing data "1", since electrons are caught in the floating gate FG, the threshold level of the transistor T2 becomes high.
It should be noted that the operation for blocking the flow of charges from the source S to which the high potential Vp is applied, to the storage node by cutting off channel portion corresponding to the gate portion NP1 of the storage node NP in the cell storing data "0" is similar to the case where a DRAM cell and an E 2 PROM cell are separated from each other without being influenced by the E 2 PROM cell during the regular operation of a DRAM. The regular operation of a DRAM will be later described.
The following is an explanation of the operation of the recall mode for transferring data stored in an E 2 PROM cell to a DRAM cell with reference to FIGS. 6 through 8.
First, the drain D (bit line BL) of the transistor T1, and the select gate SG are set to the potential Vcc, and a group of DRAM cells are selected. Data "1" is written to all the DRAM cells selected. Then, the drain D of the transistor T1 and the select gate SG are set back to the ground potential. In this state, the source S of the transistor T2 is lowered to the ground potential, and only the transistor T2, which is of a depletion type, is turned on since no electrons are caught in the floating gate FG and the threshold level thereof is lowered. Consequently, as shown in FIG. 6, in only the cells storing date "0", positive charges accumulated in the storage node NP of the DRAM cell are discharged to the source S of the transistor T2 via the drain D and channel region CH, thereby switching data stored in the DRAM cell into "0".
Further, as can be seen in FIG. 7, in the cells storing data "1", positive charges accumulated in the storage node NP of the DRAM cell are not discharged, thereby maintaining data "1" stored in the DRAM cell as it is. In other words, data is transferred from the E 2 PROM cell to the DRAM cell. After that, the source S of the transistor T2 is set to the potential Vcc, thereby electrically separating the E 2 PROM cell and the DRAM cell from each other.
The following is an explanation of the regular operation of a DRAM with reference to FIG. 9.
As shown in this figure, by setting the source S of the transistor T2 to the potential Vcc, the DRAM cell and the E 2 PROM cell are electrically separated from each other regardless of whatever the data stored in the DRAM cell or in the E 2 PROM cell is.
FIG. 10 is a plan view of a conventional nonvolatile RAM cell, whereas FIG. 11 is a plan view of a nonvolatile RAM cell according to the present embodiment. In neither FIG. 10 nor FIG. 11 is the control gate CG is not shown.
According to the embodiment, the recall gate RG, which is necessary in the conventional technique, can be removed. Further, the channel portion controlled by the projecting portion FG1 of the floating gate FG of the transistor T2 constituting the E 2 PROM, and the channel portion controlled by the gate portion NP1 of the storage node NP can be formed in a self-aligned manner. Consequently, the occupied area in a cell can be reduced to about 87% of the conventional ones, thereby enhancing the degree of integration compared to the conventional techniques.
Lastly, it should be pointed out that the present invention is not limited to the embodiment described above, and can be remodeled into various types of cells as long as the essence of the present invention is preserved.
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A semiconductor nonvolatile RAM having a dynamic RAM cell and an E 2 PROM cell. The dynamic RAM cell includes a first transistor having a current path having one end connected to a bit line and a gate connected to a word line. A storage region is connected to another end of the current path. The E 2 PROM cell includes a second transistor including a source region, a drain region, a channel region having first and second parts between the source and drain regions, a floating gate above the first part of the channel region and the source region, and a control gate. The drain of the second transistor is connected to the another end of the current path of the first transistor. Another end of the storage region is above the second part of the channel region and the floating gate. The channel region of the second transistor is rendered conductive in accordance with data stored in the storage region of the dynamic RAM cell.
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CROSS-REFERENCED RELATED APPLICATIONS
[0001] This application is a continuation of International Patent Application No. PCT/CH2007/000397 filed Aug. 14, 2007, which claims priority to German Patent Application No. DE 10 2006 038 123.8 filed Aug. 14, 2006, German Patent Application No. DE 20 2006 019 890.3 filed Aug. 14, 2006, German Patent Application No. DE 10 2006 057 578.4 filed Dec. 6, 2006, German Patent Application No. DE 20 2006 019 370.7 filed Dec. 22, 2006 and German Patent Application No. DE 10 2007 001 432.7 filed Jan. 9, 2007, the entire content of all of which is incorporated herein by reference.
BACKGROUND
[0002] The present invention relates to devices for delivering, injecting, infusing, dispensing or administering a substance, and to methods of making and using such devices. More particularly, it relates to devices, structures and/or mechanisms for setting, controlling or selecting an amount or dose of a substance to be injected or dispensed from such devices. More particularly, it relates to a lock element for locking a dose setting mechanism of an injection device, e.g. an injection device for use with a two-chamber ampoule in which two substances are contained separately from one another and are mixed prior to administering by the injection device.
[0003] If a two-chamber ampoule is incompletely or only partially screwed into an injection device, there is a possibility that the substances contained in the two-chamber ampoule will not be mixed or will be only partially mixed, in which case unmixed substances or an incompletely mixed substance could be dispensed during an injection operation.
SUMMARY
[0004] One object of the present invention is to provide an element for injection devices, by which the use of injection devices can be made more reliable, including in conjunction with two-chamber ampoules.
[0005] In one embodiment, a lock element in accordance with the present invention is used to lock a setting, priming or dose setting mechanism or a setting, priming or dose setting element of an injection device, e.g. a disposable injector or an injection pen.
[0006] In one embodiment, the present invention comprises a lock for a dosing mechanism of an injection device, the lock including at least one holding element that interacts with the dosing mechanism, or with a dosing element of the dosing mechanism, whereby an adjustment movement of the dosing mechanism or the dosing element is prevented in a starting position of the lock and is possible only after a movement or displacement of the lock or the holding element. An injection device used in conjunction with a two-chamber ampoule is encompassed, as is a method for preparing the injection device for dispensing a substance wherein the ampoule is introduced into the injection device and a lock is released when the ampoule has been introduced far enough to appropriately mix the substances in the two chambers, whereupon the mixed substances can be dispensed from the ampoule.
[0007] In one embodiment, the invention comprises a blocking element for a dosing mechanism of an injection device with at least one holding element that can interact with the dosing mechanism, or with a dosing element of the dosing mechanism, in such a way that an adjustment movement of the dosing mechanism or of the dosing element can be prevented in a starting position of the blocking element and is permitted only after a movement or displacement of the blocking element or of the holding element. The invention also relates to a method for preparing an injection device for dispensing a substance from an ampoule or two-chamber ampoule, wherein the ampoule or two-chamber ampoule is introduced, e.g. screwed, into the injection device, and the blocking or anti-rotational locking of the dosing or adjusting element or a lifting element of the injection device is only released when the ampoule has been introduced so far into the injection device that a substance can be dispensed from the ampoule in a defined or dosed manner, and/or that the substances contained in the two-chamber ampoule are appropriately or properly, e.g. completely, mixed.
[0008] In one embodiment, the lock element has at least one displaceable, e.g. flexible, retaining element, which is able to co-operate with the dose setting mechanism or dose setting element of the injection device so that a priming, dose setting, or setting movement or operation can be prevented and/or precluded. In some embodiments, the movement or operation, such as a rotating or sliding movement or an extraction movement of the dose setting element is prevented when the lock element is in an initial position due to a catch connection to the lock element, and is not triggered or initiated until the at least one retaining element has been displaced or moved, for example by a sliding movement of the lock element caused by or after introducing an ampoule.
[0009] In some embodiments, a lock element in accordance with the present invention prevents a dose setting mechanism and/or a setting or dose setting element from being operated to set a dose or prime an injection device before an ampoule is loaded in the injection device. In some embodiments, the ampoule may be a two-chamber ampoule which makes contact with the lock element, and it and/or the lock element has been pushed into or moved relative to the injection device by a pre-defined distance, e.g. 2 mm, thereby releasing the dose setting mechanism, for example by moving a retaining element engaging the dose setting mechanism.
[0010] In some embodiments, the lock element is in the form of a ring and has a contact surface for contacting an ampoule or ampoule sleeve, so that an ampoule fully or almost fully inserted or screwed into the injection device moves into contact with the lock element and drives or moves it relative to the injection device or relative to the setting mechanism on the last part of the distance of the pushing-in or screwing-in movement. In some embodiments, the at least one retaining element is biased radially inwardly or radially outwardly, and locates or is receiveable in a recess or groove of a dose setting element or a dose setting device to prevent a rotating movement or extraction of the dose setting element, e.g. the lock element is fitted in or with the injection device to afford an anti-rotation lock. In some embodiments, two or more retaining elements are provided, for example two retaining elements opposite one another on an annular lock element, which can be biased radially inwardly and locate in, lodge in or be connected to the dose setting mechanism or a dose setting element in an initial position when the ampoule has not yet been fully inserted, and/or are not pushed radially outwardly to release the dose setting element or dose setting mechanism until an ampoule has been introduced.
[0011] Another aspect of the present invention relates to a dose setting mechanism for an injection device, wherein the does setting mechanism has a lock element of the type described above and at least one dose setting element, e.g. a rotating knob or a rotating sleeve. In some preferred embodiments, the dose setting element has at least one retaining or locating element or a recess, such as a groove, with which the at least one retaining element of the lock element co-operates, i.e. in which it locates. The lock element is mounted so that it is able to slide, e.g. axially, relative to the dose setting element toward, through or out of it. The at least one retaining element of the lock element may be such that during or after a sliding movement of the lock element relative to the dose setting element, the retaining element or elements is or are moved or pushed by a ramp or inclined surface that does not slide with the lock element so that a coupling no longer exists between the lock element and the dose setting mechanism or dose setting element, which means that the dose setting element or dose setting mechanism can be operated and rotated or pulled out of the injection device to set a dose or prime the injection device.
[0012] The expression “retaining element” as used herein is intended to encompass and/or mean any element, feature, structure or the like, e.g. a recess or bore, that enables a coupling or connection, e.g., an anti-rotation lock, with another element. For example, a displaceable or flexible retaining element biased radially inwardly or outwardly may be provided on the lock element and/or on the dose setting element or dose setting mechanism, which co-operates with another retaining element or a cut-out or a recess or groove on the respective co-operating element, for example the dose setting element or dose setting mechanism or lock element, to establish a releasable coupling between the lock element and the dose setting element or dose setting mechanism. In some preferred embodiments, this coupling is then released when an ampoule is or has been introduced into the injection device to a pre-defined length, e.g. by a sliding movement of at least one retaining element caused by the ampoule being introduced and guided by a guide profile.
[0013] In some embodiments, the present invention relates to an injection device with a dose setting mechanism of the type described above and an ampoule insertion part such as an ampoule sleeve or, alternatively, an ampoule body, able to co-operate with the lock element, the dose setting element or dose setting mechanism as it is inserted. This is accomplished, for example, by moving into contact with the lock element or dose setting mechanism and causes the dose setting mechanism or dose setting element to be released during the movement or sliding action of the dose setting mechanism or lock element relative to the injection device or to a housing of the injection device caused by the movement of the ampoule as it is being inserted. In this respect, the lock element may also be part of the dose setting mechanism.
[0014] In some preferred embodiments, the injection device has a guide element, such as a ramp or a profile, extending at an angle with respect to the axial direction. The guide element is disposed relative to a retaining element of the lock element or dose setting mechanism so that an axial sliding movement of the lock element or dose setting mechanism relative to the injection device causes at least one retaining element to be moved by the guide, such that the engagement between the lock element and the dose setting element or dose setting mechanism is released.
[0015] In some preferred embodiments, a flange is provided on the injection device. The flange pushes against a stopper of the ampoule, e.g. a two-chamber ampoule, when it is introduced or screwed in. This causes the stopper to be pushed into the ampoule as the ampoule is being screwed into the injection device so that the substances contained in the two-chamber ampoule are mixed.
[0016] Another embodiment of the present invention relates to a method of preparing an injection device for dispensing a substance from a two-chamber ampoule, wherein the two-chamber ampoule is introduced into the injection device, e.g. screwed in, and a lock of a setting element or priming element of the injection device is released when the ampoule has been introduced far enough into the injection device that the substances contained in the two-chamber ampoule have been properly mixed. In some embodiments, the lock is an anti-rotation lock.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a perspective view illustrating one embodiment of the present invention, a dose setting mechanism with a released lock element;
[0018] FIG. 2 is a side view of the dose setting mechanism illustrated in FIG. 1 prior to mixing;
[0019] FIG. 2A is a sectional view along line C-C in FIG. 1 ;
[0020] FIG. 2B is a detail D from FIG. 2A ;
[0021] FIG. 3 shows the dose setting mechanism illustrated in FIG. 2 once the two-chamber ampoule has been fully screwed in and mixed;
[0022] FIG. 3A is a sectional view along line A-A in FIG. 3 ;
[0023] FIG. 3B illustrates detail B from FIG. 3A ;
[0024] FIG. 4 is a plan view of an embodiment of an injection device in accordance with the present invention with the mechanism locked;
[0025] FIG. 4A is a sectional view along line A-A in FIG. 4 ;
[0026] FIG. 5 shows the injection device illustrated in FIG. 4 with the mechanism released; and
[0027] FIG. 5A is a sectional view along line B-B in FIG. 5 .
DETAILED DESCRIPTION
[0028] With regard to fastening, mounting, attaching or connecting components of the present invention, unless specifically described as otherwise, conventional mechanical fasteners and methods may be used. Other appropriate fastening or attachment methods include adhesives, welding and soldering, the latter particularly with regard to the electrical system of the invention, if any. In embodiments with electrical features or components, suitable electrical components and circuitry, wires, wireless components, chips, boards, microprocessors, inputs, outputs, displays, control components, etc. may be used. Generally, unless otherwise indicated, the materials for making the invention and/or its components may be selected from appropriate materials such as metal, metallic alloys, ceramics, plastics, etc.
[0029] FIG. 1 is a perspective view illustrating one embodiment of a dose setting mechanism in accordance with the present invention which can be inserted in an injection device. A lock sleeve disposed at least in the front or distal part inside the housing of the injection device when the dose setting mechanism is inserted has an orifice 8 a in which a retaining element 1 a of the locking ring 1 , which is biased radially inwardly and serves as the lock element, locates once the ampoule 5 has been screwed in.
[0030] In the initial position illustrated in FIG. 2 , the locking ring 1 is mounted so that it can not rotate relative to the injection device or the housing of the injection device by an orifice in the housing, in which an element of the locking ring 1 such as a retaining element 1 a is received. Thus, the dose setting sleeve 2 is mounted in the injection device so that it can not rotate due to the retaining element 1 a locating in the orifice or groove 2 a of the dose setting sleeve 2 . The locking ring 1 is biased in the distal (or forward) direction of the injection device by a spring force, for example.
[0031] FIG. 2 is a side view showing the dose setting mechanism illustrated in FIG. 1 , with the retaining element 1 a of the locking ring 1 lying relative to the groove 8 a of the sleeve 8 so that there is still a distance d to the proximal end of the groove 8 a shown on the right-hand side of FIG. 2 .
[0032] FIG. 2A is a view in section along line C-C indicated in FIG. 2 , showing how the retaining element 1 a , biased radially inwardly, is received in a groove 2 a of the dose setting sleeve 2 and thus blocks any rotating movement of the dose setting sleeve 2 relative to the housing 3 of the injection device. When an ampoule 5 inserted in an ampoule sleeve 4 is screwed into the injection device to push the rear or proximal stopper 5 a of the ampoule into the two-chamber ampoule 5 by the flange 6 mounted on the threaded rod 7 of the injection device to enable mixing in the two-chamber ampoule 5 . The proximal end of the ampoule sleeve 4 illustrated on the right-hand side of FIG. 2A moves into contact with the front face lb of the locking ring 1 when the ampoule sleeve 4 with the ampoule 5 in it has been screwed far enough into the injection device for the flange 6 to have been pushed sufficiently far into the ampoule 5 to have caused complete or almost complete mixing of the two-chamber ampoule. When the ampoule sleeve 4 is screwed farther into the injection device, the locking ring 1 is pushed to the right in FIG. 2A , in other words in the proximal direction, due to the contact of the proximal end of the ampoule sleeve 4 with the contact face lb. This causes the guide profile 1 c provided in the locking ring 1 to move into contact with the ramp 3 a which is not able to slide relative to the injection device. The sliding movement of the locking ring 1 causes the retaining element 1 a to be pushed outwardly against the inwardly directed biasing force of the retaining element 1 a , as illustrated in detail B of FIG. 3B , thereby releasing the retaining element 1 a from its position located in the groove 2 a of the dose setting sleeve 2 so that the dose setting sleeve 2 is no longer prevented from rotating relative to the injection device.
[0033] FIGS. 3 and 3A illustrate the status of the dose setting mechanism after the locking ring 1 has moved slightly in the proximal direction by the distance d to unlock the dose setting sleeve 2 .
[0034] After the ampoule 5 has been fully mixed and the anti-rotation lock 1 a , 2 a of the dose setting sleeve 2 has been released, the dose setting sleeve 2 can be rotated by a user to set a dose or prime the injection device, so that a dose is dispensed from the ampoule 5 during an injection.
[0035] The setting mechanism is therefore mechanically locked by the two fork-shaped lock pawls 1 a of the locking ring, which extend through co-operating recesses 2 a of the rotating or dose setting sleeve 2 . Since the pen is primed by rotating the rotating ring 2 , this is now not possible because the rotation is prevented by the locking ring 1 .
[0036] To unlock the mechanism, the ampoule sleeve 4 , which was screwed into the dose setting or setting mechanism to mix the two-chamber ampoule 5 , is screwed in. On the last approximately 2 mm of the screwing-in movement, the locking ring 1 is moved from the locked position into the unlocked position by the ampoule sleeve 4 . To this end, the locking ring 1 has inclined surfaces on the inner faces of the two fork-shaped lock pawls 1 a which complement the inclined surfaces 3 a of the guide sleeve or housing. As a result, the two lock pawls 1 a are pushed out and thus release the dose setting sleeve 2 or mechanism.
[0037] The retaining element 1 a or locking ring 1 is designed so that it is pushed in the proximal direction by the ampoule sleeve 4 , which is screwed into the pen when the ampoule 5 is screwed in to mix the substance. A ramp or slide surface 3 a, provided on the housing of the injection device, causes the retaining element 1 a of the locking ring 1 , which is moved relative to the ramp 3 a by the ampoule sleeve 4 , to be pushed radially outwardly and thus release the anti-rotation lock of the dose setting sleeve 2 . Consequently, once the ampoule sleeve 4 has been fully pushed in, a dose can be set by rotating the dose setting sleeve 2 . This ensures that the dose setting sleeve 2 can not be rotated until the ampoule sleeve 4 has been fully screwed into the pen, in other words far enough for the ampoule sleeve 4 to hit the locking ring 1 and push it by a farther distance into the injection device.
[0038] FIG. 4 is a plan view showing an injection device with the mechanism locked, as illustrated along section A-A indicated in FIG. 4A . As may be seen from FIG. 4A , the retaining element 1 a , which need not necessarily be mounted on a locking ring, is urged radially inwardly and locates or lodges in a groove 2 a of the dose setting sleeve 2 , thus blocking or locking any rotating movement of the dose setting sleeve 2 relative to the housing 3 of the injection device. The ampoule 5 inserted in the ampoule sleeve 4 can be screwed into the injection device, as illustrated in FIGS. 5 and 5A . As a result, the guide profile 1 c moves into contact with the ramp 3 a , which is not able to move relative to the injection device and is pushed outwardly against the biasing action of the retaining element 1 a due to the movement of the retaining element 1 a , once the proximal end of the ampoule sleeve 4 has reached the contact surface 1 b as may be seen from FIG. 5A . As a result, the engagement of the retaining element 1 a in the groove 2 a of the dose setting sleeve 2 is released so that the dose setting sleeve 2 is no longer prevented from rotating relative to the injection device. In the case of the injection device illustrated in FIG. 5A , the ampoule has therefore been completely or almost completely inserted and a dose setting or setting movement can take place because the dose setting sleeve 2 has been released by outward movement of the retaining element 1 a.
[0039] Embodiments of the present invention, including preferred embodiments, have been presented for the purpose of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms and steps disclosed. The embodiments were chosen and described to provide the best illustration of the principles of the invention and the practical application thereof, and to enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth they are fairly, legally, and equitably entitled.
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A lock for a dosing mechanism of an injection device, the lock including at least one holding element that interacts with the dosing mechanism, or with a dosing element of the dosing mechanism, whereby an adjustment movement of the dosing mechanism or the dosing element is prevented in a starting position of the lock and is possible only after a movement or displacement of the lock or the holding element. An injection device used in conjunction with a two-chamber ampoule is encompassed, as is a method for preparing the injection device for dispensing a substance wherein the ampoule is introduced into the injection device and a lock is released when the ampoule has been introduced far enough to appropriately mix the substances in the two chambers, whereupon the mixed substances can be dispensed from the ampoule.
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TECHNICAL FIELD
[0001] The present invention relates to internal combustion engines; more particularly, to devices for controlling hydrocarbon emissions from internal combustion engines; and most particularly, to a hydrocarbon adsorber cartridge, having low resistance to air flow, for preventing hydrocarbon leakage from the intake manifold of an internal combustion engine after engine shutdown.
BACKGROUND OF THE INVENTION
[0002] Gasoline-fueled motor vehicles have many sites from which hydrocarbons (HC) may evaporate into the environment, thereby contributing to the formation of smog. HC in the atmosphere is a major contributor to smog formation. One such known site is the intake manifold of an engine. As HC emission regulations are tightened, a means is needed to prevent HC vapor from escaping from the intake manifold after engine shutdown. Known approaches have included, among others, closing off the intake and idle air with the throttle valve when the engine is shut off; adding a rigid monolith structure formed of activated carbon into the intake air flow path of the air cleaner (see U.S. Pat. No. 6,692,551 B2); and lining the intake manifold, other air ducts, and/or the air cleaner with adsorptive carbon sheeting.
[0003] Employing an engine's electronic throttle control to close the intake at shut down may impair the desirable option of a so-called “limp-home” mode in which a vehicle may be driven in the event of a partial failure of the engine electronics control system. Systems with mechanical throttles not employing electronic throttle controls typically close the throttle at shut down leaving a separate “idle air” passage open. In these systems, achieving a completely sealed manifold is difficult and expensive.
[0004] Carbon sheeting applied to inner surfaces of the manifold and air ducts is only partially successful because much HC laden air can escape the manifold without being brought into proximity with an adsorptive surface. Relatively large areas of carbon sheeting are required to ensure that an adequate quantity of HC comes into contact with the adsorber.
[0005] An adsorptive rigid monolith formed from activated carbon is unsatisfactory as it is expensive to fabricate, brittle and therefore vulnerable to breakage during assembly and use, and inherently restricts the volume of intake air. A known carbon monolith has an open area of only about 80%. The last shortcoming is especially undesirable as both engine performance and fuel efficiency can be adversely affected by undue air flow restriction.
[0006] What is needed in the art is a means for providing hydrocarbon adsorption during engine shutdown at the main air entrance to an engine while minimizing intake air restriction during engine operation.
[0007] It is a principal object of the present invention to reduce hydrocarbon emissions from a shut down internal combustion engine.
[0008] It is a further object of the invention to minimize the restriction of combustion air inflow into the engine caused by a hydrocarbon-adsorptive means.
SUMMARY OF THE INVENTION
[0009] Briefly described, a low-resistance hydrocarbon-adsorptive cartridge in accordance with the invention comprises a structure for mounting into a portion of an engine air intake system. The structure is adapted to orient and retain one or more thin sheets of activated carbon sheeting in the intake system. Preferably, a plurality of such sheets is oriented such that the cross-sectional area of each sheet is presented to the engine intake air stream, thereby minimizing reduction in total open area of the intake system. Preferably, the one or more sheets are spaced apart by a distance that is small relative to the extent of the sheets in the direction of engine air flow such that a high probability is created that hydrocarbons migrating out of a shut down engine's intake manifold will encounter a surface of at least one of the adsorptive sheets and thus be adsorbed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
[0011] FIG. 1 is an exploded isometric view of a prior art rigid monolithic hydrocarbon adsorber installed in an air intake for an internal combustion engine;
[0012] FIG. 2 is an isometric view of a first embodiment in accordance with the invention of a cartridge for use in adsorbing hydrocarbons in an engine air intake;
[0013] FIG. 2 a is a front elevational view of a variation of the first embodiment shown in FIG. 2 ;
[0014] FIG. 3 is an isometric view of a second embodiment of a cartridge;
[0015] FIG. 4 is a front elevational view of a third embodiment of a cartridge;
[0016] FIG. 5 is a side elevational view of the cartridge shown in FIG. 4 ;
[0017] FIG. 6 is a side elevational view of an alternate embodiment of the cartridge shown in FIG. 5 ;
[0018] FIGS. 7-9 are elevational views of various shaped slates in a view shown as circle A in FIG. 5 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Referring now to FIG. 1 , there is shown an exploded perspective view of a prior art engine intake air cleaner assembly 10 substantially as disclosed in U.S. Pat. No. 6,692,551 B2, the relevant disclosure of which is incorporated herein by reference. Air cleaner assembly 10 generally comprises a lower case 12 and an upper case 14 that houses one or more filter elements (not shown) for removing particulate matter from an air stream during operation of the internal combustion engine. Conduit 22 extends from upper case 14 to provide inlet-opening 24 . Preferably, conduit 22 is cylindrically shaped having an annular wall structure. During operation, inlet opening 24 permits entry of air into air cleaner assembly 10 and thence to the engine combustion chamber or chambers.
[0020] A retainer 26 , preferably made from a resilient material, is disposed onto conduit 22 of upper case 14 and has a first open end 30 and a second open end 32 .
[0021] An adsorber member 34 , also referred to as a flow regulator, is press fit into the opening defined by the first open end 30 . The conformity of shape of first open end 30 is preferably such as to produce an airtight seal between adsorber member 34 and wall 28 defining first open end 30 . As such, adsorber member 34 can generally be any shape that conforms to the shape of the opening defined by the first open end 30 . In this manner, all gases flowing into the air cleaner assembly 10 must flow through the adsorber member 34 . Likewise, any gases contained within the air cleaner assembly 10 such as, for example, those fuel gases that may accumulate in the air cleaner assembly 10 or migrate from the intake manifold after engine shutoff, must pass through the adsorber member 34 in order to enter the atmosphere.
[0022] Prior art adsorber member 34 may comprise a substrate coated with pollutant treating material. The substrate can include any material designed for use in a spark ignition or diesel engine environment and which is capable of operating at elevated temperatures dependent upon the device's location and the type of system, which is capable of withstanding exposure to hydrocarbons, nitrogen oxides, carbon monoxide, particulate matter (e.g., soot and the like), carbon dioxide, and/or sulfur, and which has sufficient surface area and structural integrity to support a pollutant treating material, and, where desired, a catalyst. Some possible support materials include cordierite, silicon carbide, metal, metal oxides (e.g., alumina, and the like), glasses, and the like, and mixtures comprising at least one of the foregoing materials. Some ceramic materials include “Honey Ceram”, commercially available from NGK-Locke, Inc, Southfield, Mich., and “Celcor”, commercially available from Corning, Inc., Corning, N.Y. These materials are preferably in the form of monoliths (e.g., a honeycomb structure, and the like). Preferred monolith supports are carriers of the type having a plurality of fine, parallel gas flow passages extending therethrough from an inlet face to an outlet face of the carrier so that the passages are open to air flow entering and passing through the monolith.
[0023] Although the substrate can have any size or geometry, the prior art size and geometry are preferably chosen to optimize surface area in the given design parameters. Preferably, the prior art substrate has a honeycomb geometry, with the combs' through-channels having any multi-sided or rounded shape, with substantially square, triangular, pentagonal, hexagonal, heptagonal, or octagonal or similar geometries preferred due to ease of manufacturing and increased surface area. Also, although each comb forming the honeycomb may be of a different size, the prior art substrate preferably comprises a honeycomb structure wherein all combs are of about equal size. The substrate may comprise about 60 to about 600 or more fluid passageways (cells) per square inch of cross section. The thickness of the substrate may be about ⅛ inch to about 12 inches with about 0.5 to about 3 inches preferred. Preferably the passages are essentially straight from their inlet to their outlet and are defined by walls in which the pollutant treating material may be coated as a washcoat so that the gases flowing through the passages contact the pollutant treating material.
[0024] The pollutant treating material can be capable of adsorbing pollutants contained in the air surrounding the substrate. Although the types of pollutants may vary widely depending on the environmental conditions to which the adsorber member 34 is exposed, contemplated pollutants include, but are not limited to, saturated and unsaturated hydrocarbons, certain carbon oxides (e.g., carbon monoxide), nitrates, sulfides, ozone, and the like, and combinations comprising at least one of the foregoing. Such pollutants may typically comprise 0 to 400 parts per billion (ppb) ozone, 1 to 20 parts per million carbon monoxide, 2 to 3000 ppb unsaturated hydrocarbons such as C.sub.2 to C.sub.20 olefins and partially oxygenated hydrocarbons such as alcohols, aldehydes, esters, ketones, and the like. In a preferred embodiment, the pollutant treating material selectively adsorbs unsaturated hydrocarbons such as those unsaturated hydrocarbons utilized in fuels and byproducts caused by combustion.
[0025] The pollutant treating material may include adsorbers, such as silicate materials, activated carbon, activated carbons, sulfides, and the like, and combinations comprising at least one of the foregoing.
[0026] As noted above, a honeycomb monolith structure preferred in accordance with the prior art, although an effective adsorber of hydrocarbons and other environmental pollutants, creates a large and undesirable pressure drop and flow restriction in the intake air flow path due to a large cross-sectional area of the structure and small-diameter air passages. What is needed is a cartridge for replacing a honeycomb monolith structure which has a large adsorptive surface area to maintain high adsorption but a low cross-sectional area to reduce intake air flow restriction and large-diameter flow passages to reduce viscous drag flow losses.
[0027] Referring to FIG. 2 , a first embodiment 134 of a cartridge in accordance with the invention is suitable for use anywhere in an intake system 135 of an internal combustion engine 137 and preferably has the adsorption capabilities of prior art adsorber 34 as described above. Preferably, the embodiments shown herein can replace or substitute directly for prior art monolithic adsorber 34 .
[0028] First embodiment 134 comprises a structural housing 100 having an axis 101 and having a size and shape specifically selected to fit into a predetermined portion of the air intake ducting of an internal combustion engine, for example, cylindrical. A continuous strip 102 of a thin, flexible, activated charcoal sheet material is spirally disposed within opening 110 of housing 100 and may be bonded as by adhesive or insert molding to a plurality of radial retainers 104 to control and maintain spacing between the convolutions of the spiral. Retainers 104 may optionally include fingers 104 a for holding adjacent strips of material in place. The width of strip 102 (which is the length of the adsorption path), the number of convolutions, and the spacing of the convolutions may be varied to meet specific application requirements. Of course, the convolutions alternatively may be formed by using a plurality of individual concentric cylindrical sheet elements 102 a ( FIG. 2 a ), but the spiral configuration is currently preferred for manufacturing simplicity.
[0029] A currently preferred material for strip 102 is an activated carbon paper available from MeadWestvaco Specialty Papers, Stamford, Conn., USA. This material contains up to 50% by weight of activated carbon and avoids the problem of carbon dusting because the carbon is added to the papermaking slurry prior to paper formation, resulting in a sheet with minimum shedding.
[0030] Cartridge 100 presents only the thin leading edge 106 of strip 102 to air 140 flowing through the cartridge and thus provides a very large open area and very low air restriction in comparison to the preferred honeycomb monolith of prior art adsorber 34 which has relatively large wall cross-sections with respect to the open area.
[0031] Referring to FIG. 3 , a second embodiment 234 of a cartridge in accordance with the invention is similar to first embodiment 134 . However, the adsorptive element is formed as a plurality of corrugated sheets 202 installed longitudinally into opening 210 of housing 200 and preferably separated by spacers 204 . Preferably, sheets 202 are formed of the same carbon paper material as strip 102 . As in first embodiment 134 , cartridge 200 presents only the thin leading edges 206 of strips 202 to air 240 flowing through the cartridge and thus provides a very large open area and very low air restriction. Further, as in first embodiment 134 , the adsorptive element is curved or folded in a direction transverse to air flow through the cartridge and thus has great rigidity and dimensional stability.
[0032] Referring to FIGS. 4 and 5 , a third embodiment 334 includes a rectangular housing 300 for use with a rectangular air duct. Individual strips 302 of carbon paper material extend across an opening 310 of housing 300 , presenting strip edges 306 to air 340 flowing through the cartridge. Because strips 302 are substantially planar and thus lack the rigidity imparted by bending in embodiments 134 , 234 , unsupported strips 302 can flutter from the air flow and therefore generally require support in the form of slats 312 extending from sides 314 a , 314 b of housing 300 . Preferably, a strip 302 is disposed on each side of each slat 312 , as well as on the inner surfaces of sides 314 a , 314 b , and sides 316 a , 316 b . Strips 302 may be secured preferably by lamination with adhesive in known fashion. Of course, the number of slats 312 and the dimensions of housing 300 may be varied to meet specific application requirements.
[0033] Further, the cross-sectional shape of slats 312 may be varied to create the intended effect and surface area of strips 302 . For example, slats 312 may be planar, as shown in FIGS. 4 and 5 , or may be V-shaped ( 312 ′- FIG. 7 ), bull-nosed ( 312 ″- FIG. 8 ), or curved ( 312 ′″- FIG. 9 ) to provided a predetermined pressure drop, flow direction, and carbon surface area for an intended application. Slats 312 may also be varied in length 350 ( FIG. 6 ) to further provide a desired pressure drop, flow direction and absorptive area.
[0034] Referring to FIGS. 10-13 , a fourth embodiment 400 of a hydrocarbon-adsorptive cartridge in accordance with the invention is formed by die-cutting and folding from a suitable sheet 402 of material comprising an inert support 404 and a layer 406 containing activated carbon. Preferably, support 404 is formed of an inexpensive polymeric material, for example, polypropylene, that is capable of taking a heat set after final forming of the cartridge shape. Preferably, layer 406 is substantially equivalent or identical to carbon paper composition 102 and may be coated or bonded to support 404 . If desired, layer 406 may be coated to support 404 on both sides ( 406 a , 406 b ) to increase further the adsorptive surface area of cartridge 400 .
[0035] In an exemplary method of forming cartridge 400 , a suitably-sized portion 408 of material 402 is die-cut in a predetermined pattern 410 to form a plurality of flaps 412 which are then folded ( FIG. 13 ) to a predetermined angle 414 from portion 408 and then secured at angle 414 as by heat treating. Angle 414 may be an angle between 0 degrees and 90 degrees, as may be desired for optimal engine and adsorptive performance. Further, pattern 410 in the cutting die may be varied to provide any desired number and shape of flaps 412 . The border 416 surrounding flaps 412 defines a housing by which the cartridge may be attached or mounted.
[0036] As shown in FIG. 13 , the orientation of flaps 412 is selected to offer lesser resistance to the flow of engine induction air 450 when the engine is running. Optionally, the thickness and resilience of polymeric sheet 402 is selected to allow flaps 412 to flexibly open from a static position, to an extent, from the flow of induction air 450 and to flexibly close to the static position, after engine shut down.
[0037] While the invention has been described by reference to various specific embodiments, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the described embodiments, but will have full scope defined by the language of the following claims.
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A low-resistance hydrocarbon-adsorptive cartridge for an air intake of an internal combustion engine comprising a structure for being mounted into a portion of an engine air intake system. The structure is adapted to orient and retain one or more thin sheets of activated carbon sheeting in the intake system. Preferably, a plurality of sheets is oriented such that the leading edge of each sheet is presented to the engine intake air stream, thereby minimizing reduction in total cross-sectional area of the intake system. Preferably, the one or more sheets are spaced apart by a distance that is small relative to the extent of the elements in the direction of engine air flow such that a high probability is created that hydrocarbons migrating out of a shut down engine's intake manifold will encounter a surface of at least one of the adsorptive sheets and thus be adsorbed.
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The Government has rights in this invention pursuant to Contract DAAK60-77-C-0065 awarded by the Department of the Army.
BACKGROUND OF THE INVENTION
This invention relates generally to controlled environment agriculture apparatus and facilities more specifically to such apparatus and facilities modularized to facilitate transportability to or between installation and use sites.
As described in greater detail in copending application Ser. No. 889,965 filed Mar. 24, 1978 now U.S. Pat. No. 4,163,342 by Fogg et al, controlled environment agriculture is the cultivation of vegetable, ornamental and other plants in an enclosure within which all those environmental factors which are generally recognized as influencing plant growth, maturation and productivity, are systematically time programmed and carefully controlled. As also explained in that application, such environmental control technology may most effectively be implemented using a nutrient film technique in which the plant roots are contained in sloped troughs or gullies through which a low-volume nutrient solution flow is effected.
One of the controlled environment agriculture (CEA) problem areas to which the invention of the aforementioned Fogg et al application was directed is that of maintaining good uniformity of distribution of the supply of air to and about the plants being cultivated, throughout the CEA enclosure. With conventional air supply and distribution arrangements there normally will exist substantial inequalities of temperature and areas of stagnation of air, neither of which is conducive to optimized plant growth. These problems are compounded by the relatively close concentration of plants required for efficient utilization of the CEA enclosure space, and by the substantial infrared energy output of the high intensity lamps which are the preferred source of illumination.
To minimize these problems and to assure equalized distribution of air supply to all plants within the CEA enclosure volume, the aforesaid Fogg et al application discloses a number of alternative embodiments of air distribution control means. The present invention is directed to another such means, similar in basic purpose and operation to the air distribution control of the Fogg et al application but affording significantly better adaptability to use in transportable facilities, i.e., CEA facilities which can readily be shipped to and installed in remote locations or removed between such locations.
To facilitate such transportability, the CEA facilities of the invention are modularized by division into one or more plant growth modules and a service module which contains or carries such accessory and support equipment as the air conditioning units and the nutrient storage and supply system. The plant growth module or modules and the service module may conveniently be interconnected during installation using quick-disconnect devices in the various supply and return lines of the nutrient system, and with similarly disconnectable couplings between the air conditioning units in the service module and the air distribution and return systems in the plant growth modules. In accordance with the invention these air return systems are incorporated into plant support rack assemblies which are movably housed within the plant growth modules, and the module structures themselves require only the simplest of air fittings thus greatly facilitating module transportability and installation.
The modularized facility of the present invention is not limited in applicability to use in installations requiring transportability, but may also be advantageous for fixed installations as well. In such installations the modularized design enhances the adaptability of the facility to specific local needs, as by enabling its sizing to achieve desired output objectives and configuration of its plant support systems for optimized growth of the specific vegetables or other crops necessary to satisfy nutritional requirements or dietary preferences of the particular locality in which the facility is sited. Reconfiguration of the facility to adapt it to crop changes from season to season or locality to locality is similarly easily accomplished without modification of the basic module structure.
BRIEF SUMMARY OF THE INVENTION
The present invention provides controlled environment agriculture apparatus characterized by good transportability and ease of installation on site, while enabling the maintenance of optimized plant growth conditions readily adjustable to meet the needs of the particular cultivars being grown and of the particular environment in which the apparatus is to operate. These advantages derive in substantial part from modularity of design of the apparatus, and from an air supply and distribution system which is structurally compatible with such modularity and provides effective control of air distribution within the modules so as to assure good uniformity of air distribution to the plants growing within them.
Briefly, the air supply and distribution system of the invention in its preferred embodiment comprises a plurality of air supply outlets located near the ceiling of the module and preferably spaced fairly uniformly within it. The air system also comprises air distribution and return duct means which are formed in substantial part by the plant grow rack assemblies themselves, rather than by fixed module structures. To this end, each of the grow rack assemblies comprises one or more perforated horizontal panel members which are located just below the troughs or gullies in which the plants are grown and which are disposed in vertically spaced relationship with the module floor, so as to define horizontally extending spaces between the panel members and floor. At both sides of the rack assemblies this space is closed, being closed on at least one side by a skirt or wall member. The other side may be similarly closed or it may instead be closed by butting the rack against the adjacent wall of the module.
The rack assembly elements thus constituted define three sides of a horizontal duct which extends the full width and length of each rack: the fourth side is defined either by additional imperforate horizontal panels mounted below and parallel to the perforated upper panels, or, preferably, by the floor itself. Then, when the several racks of the array are snugged up against each other without spacing between them, their top and side panels define, together with the floor or with the bottom panels if such are provided, a continuous duct which extends the full length of the rack array. Air ingress to this duct from the interior of the module is through the perforated surfaces of the rack panel members. The perforations in these panels serve as air flow control devices which, due to the substantially uniform pressure differential across all of them, tend to maintain equalized flow through each. They serve thus as air flow control means, and since the perforations of each rack assembly are individual to it they provide equalization of air flow and more uniform velocity of air movement over the entire surface of the rack array.
Associated with the grow modules is a service module containing the air handlers and other auxiliary equipment such as nutrient storage and supply systems as well as the electrical power and control systems for the facility. The air handlers located in this service module are coupled through quick-disconnect devices to an air supply plenum and through it to the air supply distribution means, and to a return plenum having an opening against which the proximate one of the plant grow racks is butted to provide free communication between the return plenum and the return duct formed by and beneath the plant grow rack array as previously described. The remote end of the return duct is closed as by a panel or skirt affixed to the outside face of the end rack assembly.
The racks conveniently may be wheeled or otherwise mounted for movement within the module. During such movement the air return duct and the control of distribution of return air as just described is necessarily disturbed, but normally such disturbances need be permitted to continue only for short times and hence they do not significantly interfere with plant growth or productivity. At least one of the modules may be provided also with a nursery facility which may conveniently be located above the return air plenum just described.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel and distinctive features of the invention are set forth in the claims appended hereto. The invention itself, however, together with various of its further objects, features and advantages, may best be understood by reference to the following detailed description when read in conjunction with the accompanying drawings, in which:
FIG. 1 is a part-sectional plan view of a controlled environment agriculture facility in accordance with the invention;
FIG. 2 is a part-sectional view through one of the plant growth modules and a part of the service module comprising the facility of FIG. 1;
FIG. 3 is a plan view of the module of FIG. 2 illustrating the arrangement of flow control apertures in the grow rack assemblies within the module; and
FIG. 4 illustrates a detail of the rack structure in the module of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With continued reference to the drawings, wherein like reference numerals have been used throughout to designate like elements, FIG. 1 illustrates a transportable controlled environment agriculture facility incorporating three plant grow modules 11, 12 and 13 together with one service module 15 which provides all the required support functions for the plant grow modules. The grow modules and the service module all may conveniently and economically be adapted from conventional trailer or field shelter type structures, assembled onsite to the configuration shown with the grow modules butted up against one or both sides of the service module for receiving support services therefrom. Depending upon transport and site requirements, the units may be provided with wheeled undercarriages, and if desired the grow modules may be provided with collapsible wall structures to facilitate transport and reduce shipping costs.
The service module contains among other support equipment items a number of air-handling units 17, 18 and 19, normally one for each of the grow modules 11-13. The compressor or heat pump units 21 associated with these air-handlers preferably are located just outside the service module, and as illustrated these units may conveniently be mounted on decks 23 located at either or both ends of the service module. At one end, an air lock 25 provides access to the service module and, through it, to the grow modules. Various items of support apparatus, such as nutrient tanks 27, associated pump and control equipment also forming part of the nutrient supply system, electrical equipment as at 29, and similar auxiliary equipments may be housed within the service module as convenient.
Within each of the plant grow modules 11-13, there is located a plurality of plant grow rack assemblies disposed in juxtaposed relation with each other such that the assemblies together form a rack array 31 extending substantially the full length of the module. Sufficient space is required at one end of the module for the return plenum 33 forming part of the air system to be described, and at the other end some space is left open so as to enable movement of the racks as necessary to provide access to the individual racks and to the plants carried on them, when access is needed for purposes of planting, pruning and other plant husbandry tasks.
As shown in FIGS. 1 and 2, the grow module 11 is positioned against the service module 15 with the end wall 35 of the former abutting or closely adjacent to the side walls 37 of the latter. Aligned openings 39 cut in the opposed walls of the modules provide doors for personnel access to the grow modules, and if desired those modules may also include exit doors (not shown) at their opposite ends for emergency use.
As best seen in FIG. 2, the air handler 17 includes a supply duct 41 which opens through a quick-disconnect coupling 43 and ducting 45 into a supply plenum 47. The coupling 43 may as illustrated comprise simply a pair of aligned openings in the juxtaposed wall members of the plant grow and service modules, with a surrounding annular seal member 48 of resilient material compressed between the wall members. Plenum 47 supplies air to a plurality of apertured tubes 49 which are disposed parallel to each other adjacent to the ceiling of the module and serve as distribution headers. These headers conveniently may be formed of film plastic which collapses when the pressurized air supply to them is cut off; to hold them in position under such conditions the cords 50 by which the free ends of the tubes are tied closed may be affixed to any convenient support, as for example to an adjacent end wall of the module, to thus maintain the tubing in stretched condition ready for inflation upon supply of air pressure to its interior.
The air supply preferably is at a pressure substantially greater than atmospheric, so as to enhance the equalization of air distribution through the header apertures and throughout the enclosed space within the module, and to maintain the module air pressure level at a substantial differential over atmospheric. This minimizes the possibility of entrance of external air into the module except through the air conditioning system. The air lock 25 previously mentioned serves the same purpose and conserves against air loss when the module doors must be opened for personnel ingress and egress.
The air system is of closed loop or recirculating type with return air from the module being coupled to the return air plenum 33 through a return duct which, in accordance with the invention, is formed by the plant grow rack array itself. As shown, each of the rack assemblies 51 comprises frame members 53 defining a rectangular base structure which conveniently may be provided with casters or wheels 55 as shown to provide mobility of the rack assemblies. Each rack frame or base structure provides support for a pair of elongated trough members 57 which span the width of the rack and which are supported on rods 59 mounted at different heights at its opposite ends. This mounting imparts sufficient slope to the trough members for gravity-induced flow of nutrient solutions through the plant grow gullies 61 one of which is supported on each of the trough members.
These gullies 61, which preferably are formed of a plastic material bent or folded to the configuration shown, are of length substantially equal to the widths of the racks and are spaced from each other to provide room for plant growth and for free flow of air between adjacent gullies and between the trough members which support them. The racks 51 may also include plant support members 63 for training and supporting the upper growth of the plants as illustrated at the right in FIG. 2. The several rack assembly elements thus far described may be of the form shown and described in greater detail in the aforementioned copending application of Fogg et al.
Each of the plant grow rack assemblies further comprises a horizontal plate of panel member 65 which spans the length and width dimensions of the rack and is disposed beneath the trough members 57 in parallel and spaced relationship with the module floor 67 so as to define therewith a space extending longitudinally of the rack array and transversely for the full width of the racks of the array. As best shown in FIG. 3, each of these rack panel members 65 is provided with a plurality of spaced apertures 68 of relatively small diameter, preferably approximately one to two inches in diameter depending on the total number of apertures, with the apertures being distributed substantially uniformly along the length of the panel member.
As seen in FIGS. 3 and 4, in which the plant grow gullies 61 and troughs 57 have been omitted, the sides of the rack base structures are provided with depending skirts 69. Such skirts may be provided on both sides of the racks as shown in FIG. 4 or, if preferred, only on the side removed from the module wall 71 with the wall itself being employed to close off the space beneath the rack panel members on the other side by positioning the rack against it. The one rack assembly most remote from the supply end of the module includes a transversely extending skirt element 73 to close off access to the space beneath the rack assemblies on this end.
As will be obvious from what has already been said, the space thus formed between the rack panel members 65 and the floor 67 (or, if preferred, a second horizontal panel member of imperforate material carried by each rack assembly just above the floor) defines a substantially enclosed air space to which the entrance of air is controlled by the apertures 68 and from which the only exit opening is that at the end of the rack assembly array adjacent to the air return plenum 33. Here, this plenum is formed with an opening which is complementary in dimensions and shape to the rack assemblies so that when the adjacent assembly is butted up against the plenum the air return duct formed between the rack array structure and the opposing floor surface opens directly into the plenum, thus completing a path for the flow of return air back to the air handler 17. In this way air circulation is continuous with temperature and humidity control for the circulating are preferably being provided as more fully explained in the aforementioned Fogg et al application.
Since with this arrangement each of the rack assemblies has associated directly with it its own group of air flow control apertures 68, and since each of those apertures tends to maintain equalized flow of air due to the substantial equality of pressure differential across all the apertures throughout the module, good uniformity of distribution of air flow over each of the rack assemblies within the module is thus assured, and inequalities of temperature and areas of stagnation of air are avoided.
To enable access to the individual racks of the array, and access to the plants carried by them for purposes of plant care activities such as pollenization, pruning and harvesting, guide rails 75 may be provided as shown affixed to the module floor, to constrain motion of the rack assemblies to movements parallel with their width dimensions. Of course, when the rack assemblies are thus moved, the integrity of the return air duct formed by them no longer exists, and the return air may then flow directly into the open end of whatever portion of the array remains still connected to the plenum 33. Such condition continues only temporarily, however, so it does not significantly affect plant growth or productivity.
Referring again to FIG. 2, illumination of intensity and spectral characteristics optimized for plant growth is provided by a bank of overhead high intensity discharge lamps 77, the ballasts associated with which are indicated at 79. Nutrient may be supplied to the plant grow gullies 61 from a tank 81 through supply fittings enabling movement of the plant grow rack assemblies 51 either by coupling through flexible hoses or using supply and return plumbing as shown and described in detail in the aforementioned Fogg et al application.
Conveniently, the upper surface of the air return plenum housing 33 may be used as a nursery area for starting seeds, with a bank of fluorescent lights 83 being provided for illumination of the seedlings. As the seedlings grow, they may be transferred initially to the bench area 85 just above, for acclimation to the lighting and other environmental conditions of the module itself, before final transplantation into the plant grow gullies 61.
As will be apparent to those skilled in the art, the modularized controlled environment agriculture facility of the present invention enables very quick assembly with greatly facilitated module transportability and installation. The modularized design is also of advantage in fixed installations in that it facilitates sizing to achieve desired output objectives and reconfiguration for adaptation to crop changes and local conditions, permitting individual control of the separate modules as necessary to the requirements of the particular crop to be grown in that module. The air distribution system affords good control of air distribution within the modules, without need for complex distribution structure built into the module itself, and with the air return flow control and ducting instead provided as integral parts of the grow rack assemblies.
In addition to the several possible modifications in and alternatives to the specific embodiment of this invention described in the foregoing, various others will be obvious to those skilled in the art. It accordingly should be understood that the appended claims are intended to cover all such modifications as fall within the true spirit and scope of the invention.
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This disclosure is of a controlled environment agriculture facility in which a plurality of plant grow support racks are structured and arranged within a plant grow enclosure to define an air return passage from the enclosure with air ingress to such passage being distributed over surfaces of the racks. This provides good uniformity of air distribution within the enclosure and affords improved transportability and installation of the facility.
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TECHNICAL FIELD
This invention relates to a system and method for automatically controlling the movement of an arm on a work machine.
BACKGROUND
Work machines are often equipped with a work machine arm capable of performing any number of tasks. For example, a work machine such as a backhoe or an excavator may include a digging work machine arm. Likewise, a work machine such as a forklift or a telescopic material handler may include a work machine arm for lifting and carrying objects. Other work machines may include work machine arms that are adapted to support vibratory compactors or other equipment.
Because controlling a work machine arm is often a complex process, an inexperienced operator may have difficulty moving an element of the work machine arm, such as a work implement, along a desired path. To simplify the coordination required to accomplish this, some work machines are provided with a single input device that controls the movement of all the components of the work machine arm. Use of a single input device may simplify the operation of the work machine arm and reduce operator fatigue.
U.S. Pat. No. 6,374,153 to Brandt et al. discloses an apparatus and method for providing coordinated control to a telescopic material handler. Often, a material handler is used to raise a pallet in a vertical direction. The coordinating apparatus of the '153 patent enables an operator to more easily control the material handler arm so that it moves along the vertical path by simultaneously changing both the length and the angle of the boom. The '153 patent discloses a control system that calculates a compensating error that may develop when one hydraulic cylinder does not receive the necessary hydraulic fluid flow due to the demand of flow from another cylinder.
At times, it may be desirable to move different components of the work machine arm in an order of priority that can be adapted to the needs of a specific work site. For example, when a work machine arm is used to dig in an area adjacent a standing structure, a bucket on the work machine arm must be extended so that the bucket edge approaches the wall before the back of the bucket. In another example, the life of a specific, expensive component of the work machine arm may be prolonged by using it only when necessary. Current work machines having systems for coordinated movement do not provide for prioritizing the movement of different components of the work machine arm.
The present invention is directed to overcoming one or more of the disadvantages of the prior art.
SUMMARY OF THE INVENTION
In one aspect, a method of controlling the movement of a work machine arm having a series of hydraulic cylinders operatively engaged with the work machine arm is disclosed. The method includes receiving a signal from an input device to change the position of the work machine arm and determining an extension amount of one or more of the series of hydraulic cylinders. The extension amount of one or more of the series of hydraulic cylinders is changed to effect the change in the position of the work machine arm. The changes in the extension amount of the one or more of the series of hydraulic cylinders are ordered based on a pre-selected priority of movement.
In another aspect, a system for controlling the movement of a work machine arm having a series of hydraulic cylinders operatively engaged with the work machine arm is disclosed. The system includes an input device operable to generate a signal to change the position of the work machine arm and at least one sensor associated with one or more of the series of hydraulic cylinders for determining an extension amount of the one or more of the series of hydraulic cylinders. A control module is adapted to receive the signal from the input device and to change the extension amount of one or more of the series of hydraulic cylinders to affect the change in the position of the work machine arm. The changes in the extension amount of the one or more of the series of hydraulic cylinders are ordered based on a pre-selected priority of movement.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic illustration of a portion of a work machine suited for use with the present invention.
FIG. 2 is a block diagram illustrating an exemplary controller for operating a work machine arm.
FIG. 3 is a flow chart showing an exemplary method for controlling a work machine arm using a pre-selected priority of movement.
FIG. 4 is a flow chart showing an exemplary method of extending a work machine arm using a pre-selected priority of movement.
FIG. 5 is a flow chart showing an exemplary method of retracting a work machine arm using a pre-selected priority of movement.
DETAILED DESCRIPTION
FIG. 1 is a work machine 100 shown in relevant portion as a backhoe loader, that may be used for a wide variety of earth-working and construction applications. Although the work machine 100 is shown as a backhoe loader, it is noted that other types of work machines 100 having multiple linkages, e.g., excavators, front shovels, material handlers, and the like, may be used with embodiments of the disclosed system.
The work machine 100 includes a work machine arm 102 having a boom 104 , a stick 106 , an extendable stick (E-stick) 108 , and a work implement 110 , all controllably attached to the work machine 100 . A boom cylinder 112 extends from the boom 104 to a body of the work machine 100 and is adapted to pivotally move the boom 104 with respect to the body of the work machine 100 . A stick cylinder 114 extends between the stick 106 and the boom 104 and is adapted to move the stick 106 with respect to the boom 104 .
An E-stick cylinder 116 extends between the stick 106 and the E-stick 108 . The E-stick 108 and the E-stick cylinder 116 are contained within the stick 106 so that the E-stick 108 controllably slides, i.e., extends and retracts, relative to the stick 106 . The work implement 110 is pivotally connected to the E-stick 108 and is moved by a work implement cylinder 118 , extending from the E-stick 108 to the work implement 110 .
Hydraulic cylinder valves, shown in FIG. 2 , may control the extension and retraction of the hydraulic cylinders 112 , 114 , 116 , 118 . A boom valve 208 may be associated with the boom cylinder 112 , a stick valve 210 may be associated with the stick cylinder 114 , an E-stick valve 212 may be associated with the E-stick cylinder 116 , and a work implement valve 214 may be associated with the work implement cylinder 118 . The position of valves 208 , 210 , 212 , 214 may be controlled to coordinate the flow of hydraulic fluid to thereby control the rate and direction of movement of the associated hydraulic cylinder 112 , 114 , 116 , 118 . It should be noted that the term “extension amount” represents both the amount of extension or retraction of the hydraulic cylinders 112 , 114 , 116 , 118 .
FIG. 2 shows a controller 200 for operating and controlling the movement of the work machine arm 102 . As described in greater detail below, the controller 200 may be adapted to move the components of the work machine arm 102 in an order that is based on a pre-selected priority of movement. For the purposes of this application, the term “pre-selected priority of movement” refers to a hierarchy of movement where the relative position of one or more of the hydraulic cylinders 112 , 114 , 116 , 118 is changed only after another of the hydraulic cylinders 112 , 114 , 116 , 118 is extended or retracted beyond a pre-designated position or amount. Accordingly, the pre-selected priority of movement prioritizes the movement of the boom cylinder 112 , the stick cylinder 114 , the E-stick cylinder 116 , and the work implement cylinder 118 . The cylinder with the higher priority is moved to or beyond a certain point before moving a cylinder with lower priority
The controller 200 includes an input device 202 and a control module 204 for operating valves 208 , 210 , 212 , 214 to control the position and movement of hydraulic cylinders 112 , 114 , 116 , 118 on the work machine arm 102 . It may also include displacement sensors 216 , 218 , 220 , 222 associated with, and adapted to monitor the position of the hydraulic cylinders 112 , 114 , 116 , 118 . A mode selector 224 may also be associated with the control module 204 .
The input device 202 could be a joystick, keyboard, lever, or other input device known in the art. Adapted to generate a desired movement signal, the input device 202 receives an input from an operator and sends it to the control module 204 . In the exemplary embodiment shown, the controller 200 includes a single input device for controlling the operation of the boom cylinder 112 , the stick cylinder 114 , the E-stick cylinder 116 , and work implement cylinder 118 . However, other input devices may be used to control the operation of one or more of the cylinders independent of the input device 202 and the pre-selected priority of movement.
For example, in one exemplary embodiment, the input device 202 controls only the movement of the stick cylinder 114 , the E-stick cylinder 116 , and the work implement cylinder 118 . In this exemplary embodiment, the boom cylinder 112 is controlled by a separate input device for independent control of the boom 104 . Accordingly, in this embodiment, only the stick cylinder 114 , the E-stick cylinder 116 , and the work implement cylinder 118 are subject to the pre-selected priority of movement.
The control module 204 may include a processor 205 and a memory device 206 . The memory device 206 may store one or more control routines or prioritized modes, which could be software programs, for controlling the work machine arm 102 based on the pre-selected priority of movement. The processor receives the input signal from the input device 202 and executes the routines or prioritized modes to generate and deliver a command signal to actuate the hydraulic cylinder valves 208 , 210 , 212 , 214 that are associated with the hydraulic cylinders 112 , 114 , 116 , 118 of the work machine arm 102 according to the pre-selected priority of movement.
As shown in FIG. 2 , a displacement sensor may be associated with each hydraulic cylinder. For example, a boom displacement sensor 216 may be associated with the boom cylinder 112 , a stick displacement sensor 218 may be associated with the stick cylinder 114 , an E-stick displacement sensor 220 may be associated with the E-stick cylinder 116 , and a work implement displacement sensor 222 may be associated with the work implement cylinder 118 . The displacement sensors 216 , 218 , 220 , 222 may be used to measure the extension amount of the hydraulic cylinders 112 , 114 , 116 , 118 . The displacement sensors 216 , 218 , 220 , 222 may be in communication with the control module 204 , and may provide signals to the control module 204 indicative of the cylinder extension amounts. The control module 204 may monitor one or more of the displacement sensors 216 , 218 , 220 , 222 at a single time, but does not need to monitor them all at the same time. The control module 204 may use the information received from the displacement sensors 216 , 218 , 220 , 222 to prioritize and order movement of the work machine arm 102 based on the pre-selected priority of movement.
In the exemplary embodiment shown, the controller 200 includes more than one control routine or prioritized mode. Accordingly, a mode selector 224 is provided in communication with the control module 204 . The mode selector 224 is an input device that allows an operator to select or choose from the available modes, and could be a toggle, joystick, dial, or any other input device known in the art. Accordingly, the operator can select the priority of movement of the work machine arm 102 that will provide the desired results for the work site.
The work machine 100 may include any number of modes and each mode may be different and may be based upon a specific use or function of the work machine. For example, one exemplary mode may be a digging mode, where the pre-selected priority of movement requires that the stick cylinder 114 and the boom cylinder 112 be substantially fully extended before allowing movement of either the work implement cylinder 118 or the E-stick cylinder 116 . The priority of movement may allow simultaneous extension of the boom cylinder and the stick cylinder, or may require that they too be moved in order, based on the priority of movement.
Other modes having a different pre-selected priority of movement may be used to accomplish other desired purposes. For example, in one exemplary mode, the pre-selected priority of movement prioritizes only the movement of the stick 106 , the E-stick 108 , and the work implement 110 . In this exemplary mode, the pre-selected priority of movement allows movement of the work implement cylinder 118 only after the stick cylinder 114 is extended or retracted beyond a designated point. And the E-stick cylinder 116 may be moved only after the work implement cylinder 118 is extended or retracted beyond a designated point. In this exemplary mode, the extension and control of the boom 104 may be operated independently of and outside of the pre-selected priority of movement. For example, control and operation of the boom 104 may be controlled separately through an input device specific to the boom 104 , such as a boom joystick.
In another exemplary mode, only the stick cylinder 114 and the work implement cylinder 118 are controlled by the pre-selected priority of movement. Accordingly, the pre-selected priority of movement allows movement of the work implement cylinder 118 only after the stick cylinder 114 is extended or retracted beyond a designated point. In this exemplary embodiment, the movement of the E-stick cylinder 116 and the movement of the boom cylinder 112 may be independently controlled by, for example, a separate boom joystick and a separate E-stick joystick.
In yet another exemplary mode, the pre-selected priority of movement controls only the stick cylinder 114 and the E-stick cylinder 116 . Accordingly, the pre-selected priority of movement may allow movement of the E-stick cylinder 116 only after the stick cylinder 114 is extended or retracted beyond a designated amount. In this exemplary mode, the boom cylinder 112 and the work implement cylinder 118 may be independently controlled and not based on the priority of movement. In any exemplary mode, the pre-selected priority of movement during retraction of the work machine arm 102 may or may not be the reverse of the pre-selected priority during extension of the work machine arm 102 . Other modes would be apparent to one skilled in the art.
It should be noted that any mode may be adapted to include an optional transitioning feature for smoothly transitioning the movement from one hydraulic cylinder to the next hydraulic cylinder. This transitioning feature may be used to slow, or ramp down the velocity of one hydraulic cylinder when it is extended or retracted beyond the pre-designated position, while at the same time, ramping up the velocity of the next hydraulic cylinder. So doing provides a smooth transition between hydraulic cylinders as the work machine arm is operated.
FIG. 3 is a block diagram 300 showing steps for moving the work machine arm 102 based on the pre-selected priority of movement. The flow chart 300 begins at a start step 302 . At a step 304 , an operator selects a mode on the work machine 100 using the mode selector 224 . The selected mode may be any routine or process that controls the movement of the work machine arm 102 using a pre-selected priority of movement.
At a step 306 , the input device 202 generates a signal to change the position of the work machine arm 102 . The signal is sent from the input device 202 to the control module 204 . At a step 308 , the control module 204 determines the extension amount of the hydraulic cylinders 112 , 114 , 116 , 118 on the work machine arm 102 based upon measurements taken and signals received from the respective displacement sensors 216 , 218 , 220 , 222 . At a step 310 , the control module 204 adjusts the extension amount of one or more of the hydraulic cylinders 112 , 114 , 116 , 118 on the work machine arm 102 according to the priority of movement for the mode, and further based upon the signal received from the input device 202 . At a step 312 , the flow chart 300 ends.
The flowcharts of FIGS. 4 and 5 illustrate an exemplary method of extending and retracting a work machine arm according to an exemplary pre-selected priority of movement.
INDUSTRIAL APPLICABILITY
An exemplary mode is described with reference to FIGS. 4 and 5 . FIG. 4 illustrates a flow chart 400 detailing the extension of the work machine arm 102 from a carry position to a fully extended or a maximum reach position according to an exemplary pre-selected priority of movement. FIG. 5 illustrates a flow chart 500 detailing retraction of the work machine arm 102 from the maximum reach position according to the exemplary pre-selected priority of movement. In the exemplary pre-selected priority of movement, the stick cylinder 114 has the first priority, the work implement cylinder 118 has the second priority, and the extendable stick cylinder 116 has the third priority. The boom cylinder 112 , in this exemplary embodiment, is operated independent of the pre-selected priority of movement. In this example, the pre-selected priority of movement for retraction is not the reverse of the pre-selected priority of movement for extension, but instead, the same pre-selected priority of movement is assigned to both extension and retraction of the work machine arm 102 . It should be noted that the same or different pre-selected priority of movements may be assigned to extension and retraction of the work machine arm 102 .
The flow chart 400 begins at a start step 402 . At a step 404 , a signal is generated by the input device 202 to extend the work machine arm 102 . The control module 204 receives the signal at a step 406 , and monitors the positions of the hydraulic cylinders 114 , 116 , 118 associated with the work machine arm 102 , at a step 408 . This may be accomplished using the displacement sensors 218 , 220 , 222 that are associated with the hydraulic cylinders 114 , 116 , 118 and that send signals to the control module 204 indicative of the position or extension amount of the hydraulic cylinders 114 , 116 , 118 .
In this exemplary embodiment of a priority of movement mode, the stick 106 has priority over the other components of the work machine arm 102 . Accordingly, the hydraulic cylinders associated with the E-stick 108 and the work implement 110 may not be extended or retracted until the stick cylinder 114 is extended beyond a pre-selected extension amount or point. The pre-selected point may be a position where the stick cylinder 114 is substantially fully extended. Thus, the control module 204 will extend the stick cylinder 114 to the pre-selected point before moving the E-stick cylinder 116 and the work implement cylinder 118 . If the stick cylinder 114 is not substantially fully extended, the control module 204 may not move the E-stick cylinder 116 and the work implement cylinder 118 . In one exemplary embodiment, a transitioning feature may slow, or ramp down, the velocity of one hydraulic cylinder, such as the stick cylinder 114 when it is extended or retracted beyond the pre-selected point, while at the same time, ramping up the velocity of the next hydraulic cylinder, such as the E-stick cylinder 116 , to smoothly transition between cylinders. This transitioning feature may be applied to any cylinder, whether extending or retracting.
In this exemplary embodiment, and based upon the pre-selected priority of movement, the control module 204 determines whether the stick cylinder 114 is substantially fully extended, at a step 410 . If the stick cylinder 114 is not substantially fully extended, the stick cylinder 114 is further extended at a step 412 . As the stick cylinder is extended at step 412 , the position of the stick cylinder 114 is continually monitored at step 408 . Once the stick is moved to the pre-selected point or substantially fully extended at step 410 , other cylinders 116 , 118 associated with the work machine arm 102 may be allowed to further extend the work machine arm 102 according to the pre-selected priority of movement. In this exemplary embodiment, if the stick is substantially fully extended at step 410 , the work implement 110 may then be moved by the work implement cylinder 118 .
If at step 410 the work implement cylinder 118 is substantially fully extended, the pre-selected priority of movement allows movement of the work implement cylinder 118 . At a step 418 , the control module 204 determines whether the extension amount of the work implement 110 is substantially fully extended. It should be understood that due to the configuration of the exemplary work machine arm 102 shown and described with reference to FIG. 1 , that when the work implement cylinder 118 is fully retracted, the work implement 110 is fully extended, or at a maximum reach with respect to the stick 106 and the E-stick 108 .
If the work implement cylinder 118 is not fully retracted at a step 420 , the work implement cylinder 118 is further retracted. The position of the work implement cylinder 118 is continuously monitored at step 408 by the work implement displacement sensor 222 and the control module 204 . If the work implement cylinder 118 is fully retracted at step 420 , the E-stick cylinder 116 may be extended at a step 422 . Full extension of the E-stick results in the full extension of the work machine arm 102 , providing a maximum reach. Accordingly, at a step 424 , the extension ends. It should be noted that at any point during extension of the work machine arm 102 , the operator may stop the extension simply by eliminating the signal or generating a contrary signal at the input device 202 .
The flow chart 500 of FIG. 5 describes an exemplary method for retracting the work machine arm 102 from the fully extended position. The method described in flow chart 400 and the method to be described in flow chart 500 may be associated with the same mode, such as the digging mode.
The flow chart 500 starts at a step 502 . At a step 504 , a signal is generated at the input device 202 to move the hydraulic cylinders 114 , 116 , 118 associated with the work machine arm 102 . At a step 506 , the control module 204 receives the signal from the input device 202 . Because this exemplary mode is a digging mode, at a step 508 , the work implement 110 may be set at a digging angle, such as, for example, 30° with respect to the ground. Further, because the pre-selected priority of movement may be employed with a system for coordinated movement, the work implement 110 may be maintained at the digging angle during the process described for retracting other components of the work machine arm 102 .
At a step 510 , the positions of the hydraulic cylinders 114 , 116 , 118 are monitored by the displacement sensors 218 , 220 , 222 . At a step 512 , the control module 204 determines whether the stick cylinder 114 is substantially fully retracted. Because the stick cylinder 114 has the highest priority of movement, the control module 204 may not change the extension amounts of the E-stick cylinder 116 and the work implement cylinder 118 until the stick cylinder 114 is substantially fully retracted. If the stick cylinder 114 is not substantially fully retracted, at a step 514 , the stick cylinder 114 is retracted. Step 510 monitors the position of the stick cylinder to determine when the stick cylinder 114 is substantially fully retracted. According to the pre-selected priority of movement, at step 512 , after the stick cylinder 114 is substantially fully retracted, the work implement cylinder 118 may be moved next.
At a step 520 , the control module determines whether the extension amount of the work implement cylinder 118 is fully extended. When the work implement cylinder 118 is fully extended, the work implement 110 is in a fully retracted position or, if the work implement is a bucket, the work implement 110 is in a fully curled position.
If the extension amount of the work implement cylinder 118 is not fully extended, the position of the work implement cylinder 118 may be monitored by the work implement displacement sensor 222 and the control module at step 510 . If the work implement cylinder 118 is fully extended, the E-stick cylinder 116 may be retracted. When the E-stick cylinder 116 is fully retracted, the process ends at a step 526 .
In the exemplary mode described with reference to FIGS. 4 and 5 , the retraction priority is not the reverse of the extension priority. This is due to the desire during digging to minimize the use and extension of the E-stick cylinder based upon this exemplary pre-selected priority of movement.
Further, although the exemplary embodiment of a digging mode described with reference to FIGS. 4 and 5 includes a pre-designated cylinder position that is fully extended or retracted before other cylinders may move according to the priority of movement, such full extension or retraction is not required. In other embodiments, the cylinders need only be extended or retracted beyond any designated point to activate the next priority in the pre-selected priority of movement.
Although in the exemplary embodiment describe above, the boom 104 is separately operated, and not controlled by the priority of movement, in another embodiment, the boom 104 is also controlled to the priority of movement of the present invention. Additionally, although the disclosed system is described with reference to a work machine arm 102 for digging, the pre-selected priority of movement may be used on other work machines, including, for example, excavators, shovels, telescopic material handlers, forklifts, etc. For example, if the work implement were pallet forks, the pre-selected priority of movement may operate to prevent tipping the pallet forks.
In another example, the pre-selected priority of movement may be used to control a work machine arm during other work scenarios, including, for example, when the work implement 110 is a hydraulic hammer or a vibratory compactor. The pre-selected priority of movement may prioritize the movement of the stick 106 and E-stick 108 , and may be coordinated so that the hydraulic hammer or vibratory compactor is always vertical, with only the stick 108 and E-stick 110 being prioritized.
Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims.
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A method of controlling the movement of a work machine arm having a series of hydraulic cylinders operatively engaged with the work machine arm includes receiving a signal from an input device to change the position of the work machine arm and determining an extension amount of one or more of the series of hydraulic cylinders. The extension amount of one or more of the series of hydraulic cylinders is changed to effect the change in the position of the work machine arm. The changes in the extension amount of the one or more of the series of hydraulic cylinders are ordered based on a pre-selected priority of movement.
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This application is based on Provisional Application Ser. No. 61/000,122, filed Oct. 24, 2007, the priority of which is claimed.
This invention relates to an energy storage device incorporating a capacitor and a circuit allowing slow discharge of the capacitor.
BACKGROUND OF THE INVENTION
The standard approach to store electrical energy is by using electrochemical batteries. Although batteries have undergone several centuries of development, deficiencies remain particularly for applications which recently have become practical or desirable. For example, the general consensus is that a practical, inexpensive electrically driven automobile awaits the development higher capacity, less expensive batteries which can be charged sufficiently to provide a practical radius of operation. Current electrically driven vehicles are not close to being competitive, in cost or performance, with internal combustion engine driven cars and trucks. Although electrically driven vehicles have recently enjoyed considerably improved performance, internal combustion engines have also improved, meaning that the relative advantage of combustion engine vehicles remains substantial.
It is known to use a capacitor to store direct current electrical energy, particularly in smaller capacity sizes. A major problem with capacitors as energy storage devices is they discharge immediately, producing a relatively large burst of energy over a very short time. Often, this does meet the requirements of the device to be driven, i.e. often the driven device requires delivery of energy over a prolonged period of time. In other words, the discharge rate of capacitors is often not matched with the energy rate requirement of a device that is desired to be powered.
Another major problem with capacitors is the voltage declines as energy is discharged. This also produces a mismatch of the characteristics of capacitors compared to the requirements of a device to be driven. The amount of energy stored in a capacitor is a function of the square of the voltage, as follows:
energy stored= W= ½×C×E 2
where W is the energy stored in joules, C is the capacitance of the capacitor in Farads and E is the voltage of the capacitor in volts. As the energy stored in a capacitor is used, the voltage declines so that electrical motors, for example, normally cannot be driven by capacitors for a prolonged length of time.
Disclosures of interest may be found in U.S. Pat. Nos. 5,920,469 and 7,323,849 and Printed Patent Application 2008/0021602.
SUMMARY OF THE INVENTION
This invention uses a capacitor or capacitor pack of an appropriate size in conjunction with an inverter to convert direct current stored by the capacitor into alternating current. The inverter is in circuit with a variable ratio transformer so the output voltage of the device can be controlled in a suitable manner, for example to be more-or-less constant. In other words, as the capacitor discharges and produces less voltage, the transformer can be manipulated to produce an output voltage that is matched with a driven device, such as an electrical motor.
In some embodiments, the inverter used in this invention is a mechanical inverter in order to handle high voltages that currently available solid state inverters are either incapable of handling or are very expensive, it being understood that high voltage solid state inverters could be used in this invention.
Interestingly, the impedance of the transformer subjected to the alternating current acts to prevent immediate discharge of the capacitor thereby prolonging the time the capacitor can drive its work producing device. Control of the capacitor discharge can also be ensured by adding one or more capacitors in the primary transformer coil circuit.
It is an object of this invention to provide an improved technique for storing electrical energy.
Another object of this invention is to provide a technique for storing electrical energy using a capacitor and a circuit to control the discharge of the capacitor.
A further object of this invention is to provide an improved electrical storage device using a capacitor and a circuit to produce a more-or-less constant voltage output.
These and other objects and advantages of this invention will become more fully apparent as this description proceeds.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partly schematic view of an energy storage device of this invention;
FIG. 2 is a side view, partly in section, of a mechanical inverter usable in this invention;
FIG. 3 is an enlarged cross-sectional view of the inverter of FIG. 2 , taken substantially along line 3 - 3 of FIG. 2 , as viewed in the direction indicated by the arrows;
FIG. 4 is an enlarged cross-sectional view of the inverter of FIG. 2 , taken substantially along line 4 - 4 thereof, as viewed in the direction indicated by the arrows;
FIG. 5 is a diagram showing voltage patterns of one of the embodiments of this invention;
FIG. 6 is a cross-sectional view of a three phase mechanical inverter; and
FIG. 7 is a schematic view of another type transformer usable in this invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 , an energy storage device or circuit 10 comprises, as major components, a capacitor circuit 12 , an inverter 14 having an input in circuit with the circuit 12 and an output in circuit with a transformer circuit 16 .
The capacitor circuit 12 comprises one or more capacitors or capacitor packs 18 of suitable size connected to leads 20 , 22 which connect to a terminal 24 , 26 of switches 28 , 30 so the capacitor 18 may be isolated during recharging. High Farad capacitors are not currently in great demand and the capacitors available commercially are low voltage, meaning they store little power. Conversely, high voltage capacitors that are now commercially available are used to correct power factors and have low Farad design values. However, the construction of high voltage, high Farad capacitors is well within the skill of the art.
The other side of the switches 28 , 30 connect to leads 32 , 34 one of which provides a varistor 36 therein. The leads 32 , 34 terminate in an input to the inverter 14 . The parallel adjustable resistors and capacitors in the circuit 12 , and in the circuit 16 as will be more fully apparent hereinafter, serve to optimize the circuit performance regarding frequency response, losses and the like.
In some embodiments, as shown in FIG. 2 , the inverter 14 is an electromechanical inverter in order to accommodate very high voltages that might not be possible with solid state inverters. In some embodiments, solid state inverters are technically and economically feasible. There is a definite advantage to high voltage capacitor banks 18 because the amount of energy that a capacitor can store is proportional to the square of the voltage.
It will be apparent that the electromechanical inverter 14 may be of any suitable design. In some embodiments, the inputs comprise contact brushes 40 , 42 . The inverter 14 comprises a body 44 mounted for rotation in any suitable manner, as by the provision of bearings 46 , 48 mounted on aligned shafts 50 , 52 connected to insulated end caps 54 , 56 on the ends of the body 44 . The body 44 comprises a pair of conductive disks 58 , 60 in contact with the input brushes 40 , 42 . The disks 58 , 60 are isolated by a pair of insulating disks 62 , 64 .
The output end of the inverter 14 can comprise a pair of conductive semi-cylindrical elements 66 , 68 separated by an insulating layer 70 . The conductive disk 58 is electrically connected to one of the elements 66 , 68 by an insulated path 72 while the other disk 60 is electrically connected to the other element 66 , 68 by an insulated path 74 . As shown best in FIG. 4 , the insulated paths 72 , 74 can comprise metal conductors 76 , 78 surrounded by an insulating sheath 80 , 82 and terminating in the metal elements 66 , 68 . The outputs of the inverter 14 can comprise contact brushes 84 , 86 . Insulated partitions 88 , 90 can be provided on the inside of an insulated housing (not shown) to suppress arcing across the insulating partitions 62 , 64 .
The inverter body 44 may be rotated in any suitable manner, as by the provision of a small motor 92 connected to one of the shafts 50 , 52 . The inverter 14 converts direct current from the capacitor bank 18 into alternating current because the conductive element 66 is always in electrical contact with one side of the capacitor bank 18 and the other conductive element 68 is always in electrical contact with the other side of the capacitor bank 18 while the output brushes 84 , 86 alternately contact the conductive elements 66 , 68 . Those skilled in the art will recognize that the shape of the alternating current created by the inverter 14 tends to be “squarish” on an oscilloscope while conventional alternating current tends to be analogous to a sine wave. It will also be apparent to those skilled in the art that the shape of the alternating current can be modified in any suitable manner.
It will be apparent that the inverter 14 produces single phase alternating current. It will likewise be apparent that the inverter body 44 may be redesigned to produce multiphase alternating current if the requirements of the work producing device so dictate as explained in connection with FIG. 6 .
The transformer circuit 16 includes leads 94 , 96 connecting the brushes 84 , 86 to a variable ratio transformer 98 which normally converts high voltage in a primary coil 100 to a lower voltage in a secondary coil 102 . The transformer 98 may have its variable ratio feature provided in any suitable manner, such as having a movable contact on the primary coil, a movable contact on the secondary coil as shown in FIG. 1 , a movable contact on both the primary and secondary coils, stepped contacts or multiple taps on the primary and/or secondary coils with either a movable contact arm or solid state switches or any other suitable approach. In FIG. 1 , the transformer 98 includes a primary coil 100 in circuit with the inverter output brushes 84 , 86 , a secondary coil 102 , a fixed contact 104 and a movable contact 106 on the secondary coil 102 . An alternating current driven work producing device 108 is connected to the contacts 104 , 106 and is driven thereby.
In some embodiments, the voltage delivered by the transformer coil 102 is automatically controlled in any suitable manner, as by a sensor 110 measuring the voltage across the device 108 and operating a servo circuit 112 to move the contact 106 to produce a desired voltage pattern over time. In many embodiments, such as where the work producing device 108 is an alternating current motor, it is preferred to provide a more-or-less constant voltage across the contacts 104 , 106 . In other embodiments, the contact 106 may be moved in response to a signal from the sensor 110 to a data processor or computer 114 in combination with instructions from a data base or source 116 to produce a voltage pattern other than more-or-less constant. As shown graphically in FIG. 5 , the voltage appearing in the capacitor bank 18 during discharge is illustrated as curve 118 , i.e. the voltage falls off over time. In contrast, the voltage appearing on the transformer outputs 104 , 106 is, in some embodiments, more-or-less constant as shown by dashed line 120 .
An interesting feature of this invention is that the impedance in the transformer 98 inherently prolongs the duration of discharge of the capacitor banks 18 and the design of the transformer 98 may be modified to adjust the duration of discharge of the capacitor bank 18 . In some embodiments, one or more capacitors 122 may be provided in one of the transformer leads 94 , 96 in order to ensure that the energy in the capacitor bank 18 does not discharge too rapidly, but is rather used as needed by the work producing device 108 served by the transformer 98 . The capacitor 122 tunes the transformer circuit 16 to the frequency defined by the capacitor 122 , the inductance of the transformer 98 and the resistance of the circuit 16 . It will be evident that the capacitor 122 passes alternating current but not direct current. The capacitor 122 accordingly avoids “stalling” or rapid discharge of the capacitor 18 if there were a failure of the motor 92 to turn the mechanical inverter 14 . In addition, the capacitor 122 insures there will be no direct discharge of the primary energy storage capacitor 18 and its resistance adds to the impedance of the primary transformer coil 100 . In some embodiments, the capacitor 122 may be trimmed by the addition of a subcircuit 124 including a variable resistor 126 in parallel with the capacitor 122 . The variable resistor 126 allows the frequency of the transformer circuit 16 to be modified to meet conditions that may be variable from one application to the next.
Another interesting feature of this invention is the amount of energy that can be stored and then withdrawn in a prolonged manner. Table I shows a selection of capacitors of different size and their capacity to store electrical energy.
TABLE I W = ½ * C * E 2 size capacitor, voltage, energy stored, in Farads C in volts E in joules W 1 100 5,000 1 1000 500,000 1 2000 2 × 10 6 1 5000 12.5 × 10 6 1 10000 50 × 10 6 1 20000 200 × 10 6 2 100 10,000 2 1000 1 × 10 6 2 2000 4 × 10 6 2 5000 25 × 10 6 2 10000 100 × 10 6 2 20000 400 × 10 6 10 10000 500 × 10 6 10 100000 5 × 10 12
To place these numbers in perspective, an 8.6 Farad capacitor charged to 10,000 volts stores sufficient energy to drive a 20 horsepower motor for 8 hours in an ideal situation with no losses or inefficiencies. Normal losses and inefficiencies, such as wind resistance, tire friction, power transmission losses, circuit resistance, winding losses and the like, reduce this output significantly.
In order to recharge the capacitor 18 , the switches 26 , 28 are opened and a direct current source (not shown) connected to the terminals 24 , 26 . When the capacitor bank 18 is recharged, the source is disconnected and the switches 26 , 28 closed. In some embodiments, a source of high voltage is desirable to charge the capacitor 18 . In order to do this economically, suitable switches (not shown), a plug (not shown) and a rectifier (not shown) can be provided to use the transformer 98 to convert available alternating current into high voltage direct current to charge the capacitor 18 as opposed to providing a separate transformer at a charging location.
Referring to FIG. 6 , there is illustrated one approach, out of many, for designing a multiphase electromechanical inverter 128 . The inverter 128 is identical to the inverter 14 except there are three outlet brush contacts 132 , 134 , 136 spaced 120° apart. Rotation of the inverter body 138 connects the brush contacts 132 , 134 , 136 to the conductive elements 140 , 142 which are insulated from each other by the insulating partition 144 in such a manner to produce three phase alternating current. It will be apparent to those skilled in the art that many other designs of multiphase alternating current inverters are also operable in this invention.
Another interesting feature of this invention is shown in FIG. 1 . In some embodiments, a subcircuit 146 comprising a pair of leads 148 , 150 connect to the output of the secondary transformer coil 102 to provide a direct current output. In some embodiments, this may be accomplished by providing a rectifier 152 in one of the leads 148 , 150 .
Referring to FIG. 7 , there is illustrated another embodiment of a variable ratio transformer 154 having a primary coil 156 connected to an inverter for delivering alternating current from the capacitor 18 and a secondary coil 158 providing an alternating current output of suitable voltage. The secondary coil 158 includes a series of taps 160 and a movable contact arm 162 mounted for movement in a path intersecting the taps 160 to provide a reduced output voltage on the leads 164 , 166 as will be recognized by those skilled in the art. In some embodiments, a servo circuit 168 automatically adjusts the position of the movable contact arm 162 . To this end, a controller 170 determines the voltage output of the secondary coil 158 through leads 172 , 174 to control the position of the movable contact arm 162 . In addition or in the alternative, the controller 170 may determine the reference voltage of the primary coil 156 through a lead 176 and may communicate with other voltage instructions through a lead 180 connected to a data base or software instructions to control the position of the movable arm 162 .
It will be evident there are many applications for the energy storage device 10 of this invention such as a power source for golf carts, over the road or off road motor vehicles, a replacement for large battery installations, capturing energy from lightning by recharging the capacitor during a storm and later discharging the energy into the power grid, and the like. It is also apparent that this invention is useful in installations of a wide range of capacities.
Although this invention has been disclosed and described in its preferred forms with a certain degree of particularity, it is understood that the present disclosure of the preferred forms is only by way of example and that numerous changes in the details of operation and in the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.
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An electrical storage device comprises a capacitor or capacitor bank capable of storing significant quantities of electricity. An inverter in circuit with the capacitor converts direct energy of the capacitor into alternating current. A variable ratio transformer is in circuit with the output of the inverter to produce an alternating current output of controlled voltage. The impedance of the transformer acts to prolong discharge of the capacitor over a significant time period. To further control the rate of discharge of the energy storage capacitor, an additional capacitor may be provided in the transformer circuit.
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BACKGROUND OF THE INVENTION
In order to repair motors by rewinding them the old insulation must be removed or loosened and the coils separated from the cores. This can be accomplished by placing the motor in a stripping fluid which attacks the organic insulation. Such fluids are disclosed in U.S. Pat. Nos. 2,417,468; 3,335,087, 2,242,106; 3,653,099; 3,551,204, and elsewhere.
Stripping fluids are often very reactive and dangerous chemicals, and since they are often heated to increase their chemical activity they may produce fumes which are noxious, toxic, or flammable. Therefore, it is important that the apparatus in which they are used be capable of safely handling them, yet not be so complicated that the rapid stripping of successive articles is impeded.
SUMMARY OF THE INVENTION
We have invented an apparatus for removing plastics from articles by chemical stripping. Our apparatus employs three interconnected tanks, two of which are heated and provided with gas exits. Fluid can be pumped between any two of the tanks in the apparatus even though only a single pump is used.
The apparatus is efficient because articles are continuously being stripped in one of the two heated tanks. while articles in one tank are being stipped, articles in the other tank are being washed, removed, and replaced by additional articles to be stripped. The stripping fluid is then pumped from one heated tank to the other and the process continues.
The apparatus is also very safe because each heated tank is provided with a lid and gas exit. The articles are loaded into a cool empty tank instead of into a hot liquid, and the stripped articles can be washed and cooled before they need be removed and handled.
DESCRIPTION OF THE INVENTION
The accompanying drawing is a diagrammatic view of a certain presently preferred embodiment of our invention.
In the drawing, motors 1 and 2, which are to be stripped, have been placed on stands 3 and 4, respectively, in tank 5. The tank is heated by means not shown and is provided with a lid 6 which is comparable in size to the cross-sectional area of the tank so that articles can be easily inserted and removed. The lid has a gas exit 7 connected by conduit 8 to filter holder 9 which is provided with an impingement filter 10 for collecting solids and an activated charcoal filter 11 for absorbing gases. A blower 12 on the conduit exhausts the remaining gases. The lid of tank 5 is preferably provided with a conical, thin, flexible inner lid 13 having a small aperture 14 at its center. The inner lid is held to lid 6 by brackets 15, which separate the two lids to provide a narrow space 16 at the edges so that a low volume air flow through the fume disposal system will reach, in the area adjacent seal 17, a velocity high enough to catch and entrain reliably any fumes escaping past possible imperfections in that seal or its contact with inner lid 13. It is the function of this inner lid to condense vapors and permit them to drop back into the tank.
Seal 17 is preferably of a material not attacked by the stripping fluid. This seal not only keeps vapors in, but it also thermally insulates the lid from the sides of the tank, thus keeping the lid cooler and aiding in the condensation of the stripping fluid. Polytetrafluoroethylene (Teflon) is the preferred seal material because it is flexible and not attacked by most stripping fluids, but aromatic polyimides and other materials could be used in some instances.
A second heated tank 18 is equipped in the same way as tank 5 and the gas exit of its lid is also connected to filter holder 9 by a conduit 19.
To start the stripping process, tank 18 is filled with the stripping fluid 20. Three-way valve 21 having inlet-outlet port 22, outlet port 23, and inlet port 24 is turned to "empty," three-way valve 25 is turned to "fill," and blower 12 and pump 26 are turned on. Pump 26 is preferably a centrifugal pump with large rotor clearances because the stripping fluid may accumulate pieces of stripped insulation. A filter (not shown) upstream of the pump which is periodically cleaned may be used to remove debris from the fluids. The stripping fluid is thereby pumped through conduit 27 to valve 21 to conduit 28 to pump 26, conduit 29, valve 25, conduit 30, and into tank 5. Valves 21, 25, and pump 26 are turned off and tank 18 is opened, filled with articles to be stripped, and closed.
After motors 1 and 2 have been stripped, valve 25 is turned to "empty," valve 21 to "fill," and pump 26 is turned on. The stripping fluid is pumped from tank 5 through conduit 30, valve 25, conduit 28, pump 26, conduit 31, valve 21, conduit 27, and into tank 18. Valve 21 is turned to "off," valve 25 to "fill," and valve 32 to "empty."
Tank 33 is provided with a lid 34 and holds a washing fluid 35. The washing fluid is preferably one of the more innocuous components of the stripping fluid so that any washing fluid remaining in the tanks and conduits merely becomes part of the stripping fluid. The washing fluid is pumped through conduit 36, valve 32, conduit 37, conduit 28, pump 26, conduit 29, valve 25, and conduit 30 into tank 5 where it washes and cools the motors. Valves 25 and 32 and pump 26 are turned off during the wash, then valve 25 is turned to "empty," valve 32 to "fill," and pump 26 is turned on. The washing fluid is pumped from tank 5 through conduit 30, valve 25, conduit 28, pump 26, conduit 38, valve 32, conduit 36, and back into tank 33. Valves 25 and 32 and pump 26 are turned off. Motors 1 and 2 are removed from tank 5.
It is sometimes desirable to strip the insulation off a motor, but to leave the commutator insulation intact. In that event the motors are placed in tank 5 in a vertical position with their commutators up and with the bottom of the commutators at the same level. Again, stripping fluid is pumped from tank 18 into tank 5 as hereinbefore described. Now, however, when the stripping fluid reaches a level just below the bottom of commutators (a floating sensor, not shown, can indicate the fluid level in tank 5), valve 25 is turned off and valve 39 is turned to "fill." Thus, the remaining fluid in tank 18 is pumped through conduit 27, valve 21, conduit 28, pump 26, conduit 40, valve 39, conduit 41, and into heated overflow tank 42. The pump and valves are turned off, and tank 18 is washed and reloaded. When the motors in tank 5 have been stripped the fluid is pumped into tank 18 as described, then valve 25 is turned off and valve 39 is turned to "empty," and fluid is pumped from tank 42 through conduit 41, valve 39, conduits 43 and 28, pump 26, conduit 31, valve 21, and conduit 27 into tank 18.
The conduits are preferably thermally insulated when they are used to carry heated fluids. Protection of commutators can also be achieved by placing the motors on stands of appropriate height. The motors may also be placed in the tanks in baskets in order to collect the insulation which falls off. When it is necessary to remove a fluid from the apparatus valve 44 is opened and the fluid is pumped out.
Variations of the above-described apparatus are also contemplated. For example, each three-way valve can be replaced by two two-way valves, though a single three-way valve is preferred as it simplifies operation of the apparatus. Various types of lids may be used including hinged lids, lids with fluid-sealed edges lids with external condensers, and pressure cooker lids with a pressure-tight clamped seal but the lid shown is preferred as it is believed to be most practical.
The space between the inner and outer lids may be packed with steel wool to aid in condensation, but this is not believed to be necessary. The fluids may be transferred from tank to tank by means of air pressure inside the tanks, but a pump is preferred because it does not require tanks with air-tight seals.
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An apparatus and method are disclosed for stripping plastics from articles such as motors by use of a stripping fluid. The apparatus has two heated tanks each having a large lid with a gas exit, a third tank, and means for pumping fluid between any two of the tanks. After the stripping fluid in one heated tank has removed the plastic from articles in that tank, it is pumped to the second heated tank and a washing fluid is pumped from the third tank to the first tank. A fourth tank may also be used to hold excess when a heated tank capacity is not being fully utilized.
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INCORPORATION BY REFERENCE
[0001] The disclosure of Japanese Patent Application No. 2000-060806 filed on Mar. 6, 2000 including the specification, drawings and abstract, is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a heat exchange system which feeds a heat exchange medium to a fuel cell so as to exchange heat with the fuel cell, or which feeds a heat exchange medium warmed through heat exchange with a heating element, to a gas absorbing device such as a hydrogen gas absorbing alloy tank, so as to heat the gas absorbing device.
[0004] 2. Description of Related Art
[0005] In general, a fuel cell generates power in the manner as follows: hydrogen-containing fuel gas and oxygen-containing oxidizing gas are supplied to a fuel cell, so that electrochemical reactions take place at an anode and a cathode of the cell, according to reaction formulas as indicated below.
[0006] To be more specific, when the fuel gas and the oxidizing gas are supplied to the anode and the cathode, respectively, the reactions as represented by formulas (1) and (2) take place at the anode side and the cathode side, respectively, such that the fuel cell as a whole undergoes a reaction as represented by formula (3).
H 2 →2H + +2e − (1)
2H + +2e − +(½)O 2 →H 2 O (2)
[0007] H 2 +(½)O 2 →H 2 O (3)
[0008] Since these electrochemical reactions are heat generating or exothermic reactions, the inside of the fuel cell must be cooled in order to prevent the temperatures at the anode and the cathode from rising excessively. To this end, a heat exchange system is usually provided for feeding the fuel cell with cooling water as a heat exchange medium cooled by a radiator, through a cooling water passage, thereby to cool the inside of the fuel cell. One such type of heat exchange system for a fuel cell is disclosed in Japanese Patent Publication No. HEI 7-66828.
[0009] In some cases, the fuel gas to be fed to the fuel cell is supplied from a hydrogen absorbing alloy tank containing a hydrogen absorbing alloy. In general, hydrogen absorbing alloys have the property of releasing hydrogen through an endothermic reaction when heated, and of absorbing hydrogen through an exothermic reaction when cooled. Therefore, in order to extract hydrogen from the hydrogen absorbing alloy, the hydrogen absorbing alloy inside the hydrogen absorbing alloy tank must be heated as needed. To this end, the heat exchange system feeds the hydrogen absorbing alloy tank with cooling water that is a heat exchange medium warmed by heat exchange with a heating element such as a fuel cell, through a cooling water passage, thereby to heat the inside of the hydrogen absorbing alloy tank.
[0010] Thus, the heat exchange system feeds cooling water serving as a heat exchange medium to the fuel cell in order to cool it and to the hydrogen absorbing alloy tank in order to heat it.
[0011] In the fuel cell, the cooling water supplied to the cell is completely separated from the fuel gas and the oxidizing gas by separators in each single cell. When the fuel cell is used for an extended period of time, however, the sealing member that seals the periphery of each separator may deteriorate, causing the fuel gas or oxidizing gas to leak into the cooling water.
[0012] In the hydrogen absorbing alloy tank, the supplied cooling water runs through a tube while circulating within the tank, and is thus completely separated from hydrogen gas (that is, fuel gas). In some cases, the wall surface of the tube deteriorates after an extended period of use, and the hydrogen gas leaks into the cooling water.
[0013] In the conventional heat exchange system, however, no countermeasure has been taken against leakage of the fuel gas or oxidizing gas into the cooling water as the heat exchange medium. Thus, the heat exchange system may suffer from deterioration of heat exchange performance due to the presence of gas in the cooling water.
SUMMARY OF THE INVENTION
[0014] It is an object of the invention to provide a heat exchange system which can minimize the possibility of a specified gas leaking into a heat exchange medium.
[0015] To accomplish at least a part of the above object, a heat exchange system according to the first aspect of the invention includes a fuel cell that receives a specified gas and generates electric power, a heat exchange device that performs heat exchange with a heat exchange medium, a heat exchange medium passage, and a gas detector. The heat exchange medium passage circulates the heat exchange medium between the heat exchange device and the fuel cell such that the heat exchange medium can exchange heat with the heat exchange device and the fuel cell. A gas detector is provided at at least one of the heat exchange device and the heat exchange medium passage at a location to detect the specified gas that leaks into the heat exchange medium.
[0016] According to a second aspect of the invention, there is provided a heat exchange system which includes an exothermic body capable of generating heat, a gas absorbing device comprising a gas absorbing alloy that is able to absorb or release a specified gas, a heat exchange device configured and positioned to perform heat exchange with a heat exchange medium, a heat exchange medium passage and a gas detector. The heat exchange medium passage circulates the heat exchange medium among the heat exchange device, the exothermic body, and the gas absorbing device such that the heat exchange medium can exchange heat with the heat exchange device, the exothermic body and the gas absorbing device. The gas detector is provided at at least one of the heat exchange device and the heat exchange medium passage at a location to detect the specified gas that leaks into the heat exchange medium.
[0017] In the heat exchange system of the invention as described above, even where a specified gas leaks into the heat exchange medium, the gas detector immediately detects leakage of the gas, of which the driver can be promptly informed. Thus, the leakage of the gas into the heat exchange medium will not be left as it is, and otherwise possible deterioration of the heat exchange performance due to bubbling of the specified gas can be advantageously avoided.
[0018] The heat exchange system may further include a heat exchange medium storage device for storing at least an excess of the heat exchange medium when the amount of the heat exchange medium that circulates through the heat exchange system becomes excessive. In this case, the gas detector is provided at at least one of the heat exchange device, the heat exchange medium passage and the heat exchange medium storage device. The provision of the gas detector at the heat exchange medium storage device also yields the same advantage as described above.
[0019] Preferably, the gas detector is located at a portion of the heat exchange device or the heat exchange medium passage, which portion is higher in position than the other portions thereof or has a larger volume than the other portions thereof.
[0020] Since gas is normally likely to collect at a location that is higher in position or has a larger volume or capacity, the gas detector is preferably disposed at such a location so that leakage of the specified gas into the heat exchange medium can be more quickly and surely detected.
[0021] In one preferred embodiment of the invention, the heat exchange device comprises a radiator with a radiator cap located at the top thereof, and the gas detector is attached to the radiator cap.
[0022] In another preferred embodiment of the invention, the heat exchange medium storage device comprises a reserve tank, and the gas detector is attached to an upper portion of the reserve tank.
[0023] Where the radiator is used as the heat exchange device, and the reserve tank is used as the heat exchange medium storage device, the gas detector is located at the upper portion of the radiator or the reserve tank which is higher in position and has a larger volume or capacity and at which the specified gas leaking into the heat exchange medium is likely to collect. Also, the gas detector provided at such a location can be relatively easily detached or removed, thus facilitating maintenance or replacement of the gas detector.
[0024] The heat exchange system of the invention is preferably installed in a vehicle. In the case where a fuel cell and a hydrogen absorbing alloy tank are installed in an electric vehicle or a hybrid vehicle, for example, the heat exchange system installed in the vehicle permits early detection of any leakage of a specified gas into the heat exchange medium.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] [0025]FIG. 1 is a schematic view showing a heat exchange system according to a first embodiment of the invention;
[0026] [0026]FIGS. 2A and 2B are sectional views schematically showing a stack structure and a single cell structure, respectively, of the fuel cell of FIG. 1;
[0027] [0027]FIG. 3 is a schematic view showing a heat exchange system according to a second embodiment of the invention; and
[0028] [0028]FIG. 4 is a view showing an example of another location at which a hydrogen sensor may be installed.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0029] Hereinafter, presently preferred embodiments of the invention will be described. FIG. 1 is a schematic view showing a heat exchange system according to a first embodiment of the invention.
[0030] The heat exchange system of this embodiment can cool a fuel cell 30 and heat a hydrogen absorbing alloy tank 40 . The heat exchange system is installed in an electric vehicle or a hybrid vehicle or the like having the fuel cell 30 and the hydrogen absorbing alloy tank 40 .
[0031] As shown in FIG. 1, the heat exchange system mainly includes a radiator 10 , cooling water passages 60 to 64 , water pumps 70 and 76 , valves 72 and 74 , and a reserve tank 20 , and uses cooling water as a heat exchange medium flowing through the system. As the cooling water, normal water can be used, but it is preferable to use water to which anticorrosive and/or antifreeze treatment(s) have been applied.
[0032] The radiator 10 is a heat exchange device for cooling the cooling water warmed by the fuel cell 30 , and includes an upper tank 12 and a lower tank 14 for temporarily storing the cooling water, and a core 16 for passing the cooling water. Although not shown in FIG. 1, the core 16 is composed of a combination of narrow water tubes through which the cooling water runs and wavy metal plates called corrugated fins, the combination being in the form of a network.
[0033] The cooling water warmed by the fuel cell 30 flows to the upper tank 12 to be temporarily stored therein and then led to the lower tank 14 through the water tubes in the core 16 to be stored in the lower tank 14 . While the cooling water passes through the water tube, the fins that are in contact with the tubes take away or dissipate the heat, to thus cool the cooling water. The fins are cooled by the breeze while the vehicle is running, or by a cooling fan (not shown) provided behind the radiator 10 .
[0034] In this manner, the cooling water cooled and stored in the lower tank 14 flows out from the lower tank 14 to reach the fuel cell 30 through the cooling water passage 60 . A water pump 70 is provided midway in the cooling water passage 60 so as to forcibly circulate the cooling water flowing through the cooling water passage 60 . The water pump 70 and another water pump 76 which will be described later are both electrically driven.
[0035] The cooling water which has reached the fuel cell 30 enters a manifold (not shown) that allows cooling water to flow into the fuel cell 30 , and is then divided into streams flowing into cooling water channels within respective single cells so as to cool the anode and cathode of each single cell. During the flow through the fuel cell 30 , the cooling water itself is warmed by taking heat away from the anode and the cathode of each cell. The streams of cooling water that have passed through these cooling water channels again join together to reach a manifold (not shown) which allows the cooling water to flow out from the fuel cell 30 .
[0036] The cooling water that flows out from the fuel cell 30 passes through the cooling water passage 61 and is then divided into two flow paths, one of which is led to a valve 72 and the other of which is led to a valve 74 . These valves 72 and 74 selectively switch between a flow path leading the cooling water warmed by the fuel cell 30 to the hydrogen absorbing alloy tank 40 so as to heat the hydrogen absorbing alloy tank 40 , and a flow path bypassing the hydrogen absorbing alloy tank 40 .
[0037] For example, when the valve 72 is closed and the valve 74 is open, the warmed cooling water flows through the cooling water passage 62 into the hydrogen absorbing alloy tank 40 so as to heat the hydrogen absorbing alloy tank 40 . On the contrary, when the valve 72 is open and the valve 74 is closed, the warmed cooling water bypasses the hydrogen absorbing alloy tank 40 without being used to heat the hydrogen absorbing alloy tank 40 .
[0038] The hydrogen absorbing alloy tank 40 contains a hydrogen absorbing alloy 42 . As is well known in the art, the hydrogen absorbing alloy 42 has the property of releasing hydrogen through an endothermic reaction when heated, and absorbing hydrogen through an exothermic reaction when cooled. Therefore, when it is desired to extract or take out absorbed hydrogen from the hydrogen absorbing alloy tank 40 , warmed cooling water is supplied to the hydrogen absorbing alloy tank 40 so as to heat the hydrogen absorbing alloy 42 in the hydrogen absorbing alloy tank 40 as described above. On the other hand, when it is desired to store hydrogen in the hydrogen absorbing alloy tank 40 , the temperature of the hydrogen absorbing alloy 42 in the tank 40 is lowered by stopping the supply of the warmed cooling water to the hydrogen absorbing alloy tank 40 .
[0039] When the warmed cooling water is supplied to the hydrogen absorbing alloy tank 40 , the cooling water flows through a cooling water tube 44 circulating within the hydrogen absorbing alloy tank 40 so as to heat the hydrogen absorbing alloy 42 in the hydrogen absorbing alloy tank 40 .
[0040] After flowing out from the hydrogen absorbing alloy tank 40 , the cooling water that heated the hydrogen absorbing alloy 42 is returned to the upper tank 12 of the radiator 10 through cooling water passages 63 and 64 . Midway in the cooling water passage 63 , the water pump 76 is provided for forcibly circulating the cooling water which has passed through the hydrogen absorbing alloy tank 40 . Thus, the water pump 76 is driven when the valve 72 is closed and the valve 74 is open.
[0041] When the cooling water is not supplied to the hydrogen absorbing alloy tank 40 , on the other hand, the warmed cooling water that flows out from the fuel cell 30 is returned to the upper tank 12 of the radiator 10 after passing through the valve 72 and the cooling water passage 64 .
[0042] A radiator cap 18 , which also serves as a pressure regulating valve, is mounted on the top of the upper tank 12 , and a cooling water tube 65 extends from the radiator cap 18 to a reserve tank 20 .
[0043] As shown in FIG. 1, the reserve tank 20 is a simple sealed type reserve tank, and an air intake tube 66 connects to the reserve tank 20 to maintain atmospheric pressure inside the reserve tank 20 .
[0044] When the temperature of the cooling water in the upper tank 12 rises to such an extent that part of the water boils and the pressure within the upper tank 12 exceeds a predetermined level, cooling water and steam emitted from the tank 12 are pushed out through the cooling water tube 65 into the reserve tank 20 . In the reserve tank 20 , the steam liquefies and returns to water 22 without being actively cooled because of the low ambient temperature. Later, when the pressure inside the upper tank 12 becomes lower than the atmospheric pressure due to a decrease in the temperature of the cooling water in the upper tank 12 , the cooling water flows out from the reserve tank 20 and runs back to the upper tank 12 through the cooling water tube 65 .
[0045] The reserve tank 20 has a cooling water supply cap 24 mounted atop it. The cooling water supply cap 24 can be opened so that the cooling water 22 in the reserve tank 20 can be replenished when it falls below a predetermined amount.
[0046] The heat exchange system shown in FIG. 1 has been schematically described above. Hydrogen sensors 50 and 52 and so forth, which are characteristic features of the invention, will be described in detail later.
[0047] Next, a circulation path of fuel gas to be supplied from the hydrogen absorbing alloy tank 40 to the fuel cell 30 will be briefly described.
[0048] As shown in FIG. 1, a hydrogen gas is first supplied from outside to the hydrogen absorbing alloy tank 40 through a hydrogen gas inflow passage 80 . At this time, if the supply of heated cooling water to the hydrogen absorbing alloy tank 40 is stopped, and the temperature of the hydrogen absorbing alloy tank 40 falls as described above, the supplied hydrogen gas is absorbed in the hydrogen absorbing alloy 42 . Then, if the supply of the heated cooling water to the hydrogen absorbing alloy tank 40 is started, and the temperature inside the tank 40 rises, the hydrogen gas absorbed in the hydrogen absorbing alloy 42 is released therefrom. At this moment, a valve 82 is opened, and the released hydrogen gas is supplied to the fuel cell 30 through fuel gas passages 81 and 83 to serve as fuel gas in the cell. Midway in the fuel gas passage 83 are provided a hydrogen gas compressor 84 for circulating the hydrogen gas, a valve 85 for stopping the supply of the hydrogen gas to the fuel cell 30 , and a throttle valve 86 for adjusting the amount of flow of the hydrogen gas to be supplied to the fuel cell 30 . The hydrogen gas supplied to the fuel cell 30 enters a manifold for fuel gas inflow and is then divided into streams flowing into fuel gas channels within respective single cells so that the hydrogen gas is supplied to the anode of each single cell, as will be described later. The remaining hydrogen gas that was not supplied to the anode is re-collected into a manifold for fuel gas outflow and flows out from the fuel cell 30 . The hydrogen gas thus discharged is returned again to the fuel gas passage 81 through a fuel gas passage 87 and circulated.
[0049] The schematic structure of the fuel cell 30 will be described hereinafter with reference to FIGS. 2A and 2B. FIGS. 2A and 2B are sectional views schematically showing stack structure and single cell structure, respectively, of the fuel cell 30 as shown in FIG. 1. FIG. 2A shows a section of the stack structure, and FIG. 2B shows a section of the single cell structure which is an enlargement of a portion of FIG. 2A including a single cell.
[0050] As shown in FIG. 2B, a single cell is composed of an electrolyte film 35 , an anode 36 and a cathode 37 which are diffusion electrodes that sandwich the film 35 from both sides, and two separators 34 which sandwich the electrodes from both sides. The separators 34 have mutually opposed surfaces in which recesses are formed, and cooperate with the anode 36 and cathode 37 sandwiched between the separators 34 to form gas channels within the single cell. Of the gas channels thus formed, gas channels 32 formed between the separator 34 and the anode 36 allow hydrogen gas supplied as described above as fuel gas to pass therethrough, and gas channels 33 allow oxygen containing air, serving as oxidizing gas, to pass therethrough.
[0051] In the present embodiment, as shown in FIG. 2A, two adjacent separators 34 , which are located at intervals of two single cells, are in direct contact with each other, and have recesses formed in their opposed surfaces such that cooling water channels 31 are formed between the adjacent separators 34 . The cooling water supplied to the fuel cell 30 as described above is caused to flow through the cooling water channels 31 .
[0052] As shown in FIG. 2A, the cooling water flowing through the cooling water channels 31 is usually completely separated from the hydrogen gas and oxidizing gas respectively flowing through the gas channels 32 and 33 . However, as the fuel cell 30 is used for an extended period of time, cracks may be formed in the separators 34 , or a sealing member (not shown) sealing the periphery of the separators 34 may deteriorate, causing the hydrogen gas (and/or the oxidizing gas) flowing through the gas channels 32 (and 33 ) to leak into the cooling water flowing through the cooling water channels 31 .
[0053] In the hydrogen absorbing alloy tank 40 , the supplied cooling water normally flows through the cooling water tube 44 circulating in the tank 40 while being completely separated from the hydrogen gas, as shown in FIG. 1. In some cases, however, the wall surface of the cooling water tube 44 may deteriorate after a long period of use, and the hydrogen gas present in the upper portion of the hydrogen absorbing alloy tank 40 may leak into the cooling water passing through the cooling water tube 44 .
[0054] If hydrogen gas leaks into the cooling water in the above manner, the hydrogen gas turns into bubbles in the cooling water, which may possibly result in deterioration of the heat exchange performance of the entire heat exchange system.
[0055] In view of the above problem, the present embodiment adopts the following structure for detecting leakage of hydrogen gas into the cooling water early and informing the driver of the vehicle of the gas leakage.
[0056] In the heat exchange system of the present embodiment as shown in FIG. 1, the hydrogen sensor 50 is mounted in the radiator cap 18 at the top of the radiator 10 , and the hydrogen sensor 52 is mounted at the top portion of the reserve tank 20 . Each of the hydrogen sensors 50 and 52 detects even a very small amount of hydrogen if it is contained in the air, and outputs a detection signal.
[0057] The heat exchange system of the present embodiment further includes a control unit 90 and a hydrogen gas leakage warning lamp 92 provided on the dashboard of the driver's seat. The control unit 90 detects the leakage of hydrogen gas into the cooling water from a detection signal received from the hydrogen sensors 50 and 52 , and outputs a driving signal. The hydrogen gas leakage warning lamp 92 lights up when the driving signal is received from the control unit 90 .
[0058] When hydrogen gas leaks into the cooling water, the hydrogen gas turns into bubbles, which then flow through the cooling water passage together with the cooling water and collect at a portion within the heat exchange system which is higher in position and has a relatively large capacity. To be more specific, the hydrogen gas in the form of bubbles collects at the top portion of the upper tank 12 of the radiator 10 , or around the radiator cap 18 , which is located at the highest position in the heat exchange system. If the pressure inside the upper tank 12 is high, the cooling water is pushed out as described above from the upper tank 12 into the reserve tank 20 through the cooling water tube 65 so that the hydrogen gas caught within the upper tank 12 is also pushed out into the reserve tank 20 along with the cooling water. The hydrogen gas pushed out together with the cooling water turns into bubbles in the cooling water 22 and floats up to the surface of the water, to be present at the top of the reserve tank 20 .
[0059] As described heretofore, the hydrogen sensors 50 and 52 mounted in the radiator cap 18 of the radiator 10 and in the reserve tank 20 , respectively, detect hydrogen gas collected at the top of the upper tank 12 or at the top of the reserve tank 20 due to the leakage of the hydrogen gas into the cooling water, and output detection signals. Upon detecting the leakage of the hydrogen gas into the cooling water from the detection signals, the control unit 90 outputs a driving signal to the hydrogen gas leakage warning lamp 92 . The lamp 92 then lights up to inform the driver that hydrogen gas is leaking into the cooling water.
[0060] Thus, in the heat exchange system of the present embodiment, if hydrogen gas leaks into the cooling water, the hydrogen sensors 50 and 52 immediately detect the leakage, and the hydrogen gas leakage warning lamp 92 informs the driver of the leakage. Once the driver notices the lighting of the lamp 92 , the driver can ask for an inspection of the vehicle soon in order to get repairs or replacements and so forth as necessary. The hydrogen gas collected in the upper tank 12 of the radiator 10 and the hydrogen gas collected at the top of the reserve tank 20 can be easily discharged into the air by opening the radiator cap 18 and the cooling water supply cap 24 , respectively. Moreover, the hydrogen sensors 50 and 52 are installed at sites which allow the sensors to be comparatively easily detached, which facilitates the maintenance or replacement of these hydrogen sensors.
[0061] [0061]FIG. 3 is a block diagram showing the structure of a heat exchange system according to a second embodiment of the invention. The heat exchange system of the present embodiment differs from the system of the first embodiment shown in FIG. 1 in that a completely sealed type reserve tank 100 is used instead of the simple sealed type reserve tank 20 . Since the other components are identical to those shown in FIG. 1, the description of these components will be omitted.
[0062] When the pressure in the upper tank 12 exceeds a predetermined level due to a rise in the temperature of the cooling water in the upper tank 12 of the radiator 10 , the cooling water and steam emitted from the tank 12 flow into the reserve tank 100 through a cooling water tube 68 in the same manner as with the reserve tank 20 shown in FIG. 1. However, since the reserve tank 100 is of the completely sealed type unlike the reserve tank 20 , the cooling water never returns to the upper tank 12 from the reserve tank 100 through the cooling water tube 68 even if the pressure in the upper tank 12 falls due to a decrease in the temperature of the cooling water in the upper tank 12 . Instead, the cooling water 22 in the reserve tank 100 is led to the cooling water passage 60 , not through the cooling water tube 68 , but through a cooling water passage 67 after leaving an outlet formed at the bottom of the reserve tank 100 .
[0063] Since hydrogen gas that leaks into the cooling water may collect at the top of the reserve tank 100 in the present embodiment, a hydrogen sensor 52 is provided at the top of the reserve tank 100 for detecting the leakage of the hydrogen gas. Thus, the present embodiment provides the same advantages as the first embodiment. In addition, the use of the reserve tank of the completely sealed type in the present embodiment eliminates a possibility that impurities contained in the air may be introduced into the cooling water.
[0064] While the hydrogen sensors are mounted in the radiator cap 18 of the radiator 10 and at the top of the reserve tank 20 , 100 in the illustrated embodiments, such a hydrogen sensor may be installed midway in a cooling water passage connecting the radiator 10 and the fuel cell 30 or the hydrogen absorbing alloy tank 40 as shown in FIG. 4.
[0065] [0065]FIG. 4 shows an example of a location at which a hydrogen sensor may be installed. In FIG. 4, a portion of the cooling water passage 64 through which the cooling water flows into the upper tank 12 of the radiator 10 forms a circuit that projects upwards so as to bypass an obstacle(s) or the like. Since the circuit portion of the passage 64 is higher in position than the other portions, it is considered that hydrogen gas that leaks into the cooling water and turns into bubbles is likely to collect at the circuit portion. In this modified example, therefore, another hydrogen sensor 54 is provided at the circuit portion of the cooling water passage 64 .
[0066] Thus, the same advantages as provided in the illustrated embodiments may be obtained by providing an additional hydrogen sensor at a portion of the cooling water passage which is higher in position than the other portions.
[0067] It is to be understood that the invention is not limited to details of the illustrated embodiments, but may be embodied with various changes or improvements without departing from the scope of the invention.
[0068] In the heat exchange system of each of the above embodiments, the fuel cell 30 is cooled by using the cooling water, and the hydrogen absorbing alloy tank 40 is heated by using the cooling water that has been warmed through the cooling of the fuel cell 30 . However, the invention is not restricted to this type of system. For instance, the invention is applicable to a system in which cooling water is used only to cool the fuel cell 30 . In another example of the heat exchange system, the hydrogen absorbing alloy tank 40 can be heated by cooling water that has been warmed not by taking heat away from the fuel cell 30 but by cooling another heat-generating or exothermic body (auxiliary equipment or an engine in the case of a hybrid car, for example).
[0069] In the illustrated embodiments, the hydrogen sensors 50 , 52 , and 54 detect the presence of hydrogen in the air. However, if a sensor capable of detecting the presence of hydrogen in a liquid is developed, such a sensor could also be used. In that case, sensors could be installed at any location in the path through which the cooling water flows, without taking account of the height in position or the likelihood of collection of hydrogen gas in the form of bubbles.
[0070] While leakage of hydrogen gas into cooling water is detected by the hydrogen sensors in the illustrated embodiments, leakage of, for example, oxidizing gas into cooling water may be detected by using a gas sensor for detecting oxidizing gas.
[0071] In the illustrated embodiments, cooling water is used as a heat exchange medium. However, the invention is not restricted to this, but may use a heat exchange medium other than water.
[0072] In the above embodiments, the warning lamp 92 is used to visually inform the driver that hydrogen gas is leaking into the cooling water. Alternatively, a beeper or a speaker can be used to give notification by sound.
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A heat exchange system includes a fuel cell that receives a specified gas and generates electric power, a heat exchange device that exchanges heat with a heat exchange medium, a heat exchange medium passage, and a gas detector. The heat exchange medium passage allows the heat exchange medium to circulate between the heat exchange device and the fuel cell such that the heat exchange medium can exchange heat with the heat exchange device and the fuel cell. The gas detector is disposed at at least one of the heat exchange device and the heat exchange medium passage to detect the specified gas that leaks into the heat exchange medium.
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TECHNICAL FIELD
[0001] The present invention relates to a method of producing a hydrophilic modified polyrotaxane.
BACKGROUND ART
[0002] “Slide-ring gels”, new gels different from physical gels and chemical gels, have been developed in recent years. A compound that is used for such slide-ring gels and is drawing attention is a crosslinked polyrotaxane.
[0003] A crosslinked polyrotaxane has a structure in which linear molecules are threaded through cyclic molecules in a skewered manner and the cyclic molecules are movable along the linear molecules (has a pulley effect). The pulley effect allows the crosslinked polyrotaxane to be viscoelastic and to uniformly distribute tensile force applied thereto. The crosslinked polyrotaxane is therefore not likely to have cracks or flaws, i.e., has excellent characteristics that conventional crosslinked polymers do not have. Such a crosslinked polyrotaxane is obtainable by placing a capping group at each end of a linear molecule of pseudopolyrotaxanes and to prevent dissociation of the cyclic molecules of pseudopolyrotaxanes, and crosslinking the resulting polyrotaxanes. The pseudopolyrotaxanes have a linear molecule which is included in the cavities of the cyclic molecules in a skewered manner.
[0004] For the cyclic molecules of the polyrotaxane, cyclodextrins are favorably used. Cyclodextrins, however, contain a large number of hydroxy groups and these hydroxy groups are firmly bonded to one another by a large hydrogen bonding strength. Therefore, the resulting polyrotaxane is hardly dissolved in water, limiting the application range.
[0005] Patent Literature 1 discloses a hydrophilic modified polyrotaxane that is dissolved in water or a water-based solvent, which may extend the application range to coatings, adhesives, and the like. A hydrophilic modified polyrotaxane is typically produced by modifying the hydroxy groups on a cyclodextrin of a polyrotaxane with hydrophilic modifying groups in a solvent, thereby yielding a hydrophilic modified polyrotaxane in an aqueous solution state. This aqueous solution of the hydrophilic modified polyrotaxane may be used as it is, i.e., in a solution state without drying. When a solution of the hydrophilic modified polyrotaxane having a higher concentration than the obtained solution is required, however, a complicated process for concentration is needed. In addition, particularly if the solution of the hydrophilic modified polyrotaxane is to be given another function through a chemical modification and the solution contains water, the water in the solution may inhibit the chemical modification reaction, limiting the application range. To prevent this, Patent Literature 1 discloses a method of producing a solid hydrophilic modified polyrotaxane by freeze-drying of a solution of the hydrophilic modified polyrotaxane.
CITATION LIST
Patent Literature
[0000]
Patent Literature 1: JP 2007-63412 A (Japanese Kokai Publication No 2007-63412)
SUMMARY OF INVENTION
Technical Problem
[0007] When a solution of a hydrophilic modified polyrotaxane is dried to produce a solid hydrophilic modified polyrotaxane in an industrial scale, such a freeze-drying method as disclosed in Patent Literature 1 requires a large cost for equipment and for running of the equipment. In addition, freeze-drying is not suitable for drying such a dilute solution of the hydrophilic modified polyrotaxane as disclosed in Patent Literature 1 because it takes a huge amount of time.
[0008] Furthermore, a drying method such as vacuum drying causes the resulting hydrophilic modified polyrotaxane to be aggregated. Therefore, in order to efficiently dissolve the aggregated hydrophilic modified polyrotaxane in water or a water-based solvent without lumps, a complicated process such as crushing the aggregated hydrophilic modified polyrotaxane into a powder and then adjusting the particles of the powder to appropriate sizes by classification and the like is required.
[0009] The present invention aims to solve these problems and provide a method of producing a hydrophilic modified polyrotaxane, which enables production of a dried hydrophilic modified polyrotaxane in an industrially advantageous way.
Solution to Problem
[0010] The present invention relates to a method of producing a hydrophilic modified polyrotaxane, including: a hydrophilic modification step of preparing a solution of a hydrophilic modified polyrotaxane by modifying a polyrotaxane which includes a cyclodextrin, a polyethylene glycol included in the cavities of the cyclodextrin molecules in a skewered manner, and a capping group that is placed at each end of the polyethylene glycol and prevents dissociation of the cyclodextrin molecules from the polyethylene glycol, said modification of the polyrotaxane being performed by modifying all or part of hydroxy groups on the cyclodextrin with hydrophilic modifying groups; and a drying step in which the prepared solution of the hydrophilic modified polyrotaxane is formed into a thin film state and dried.
[0011] The present invention is described in detail below.
[0012] The present inventors found that drying methods such as vacuum drying cause aggregation in the resulting hydrophilic modified polyrotaxane, and in addition, the storage stability of the hydrophilic modified polyrotaxane may be insufficient. For example, when a hydrophilic modified polyrotaxane is produced by vacuum drying at 40° C. to lower than 100° C., by heating the solution to the boiling point of water and then drying at normal pressure, or the like, the storage stability becomes remarkably poor and decomposition tends to occur at a storage temperature of 30° C. to 40° C. This causes isolation of the cyclodextrin in which all or part of the hydroxy groups are modified with hydrophilic modifying groups (hereinafter, also referred to as modified cyclodextrin). The isolation of the modified cyclodextrin caused by decomposition of the hydrophilic modified polyrotaxane degrades the characteristics of the resulting crosslinked polyrotaxane, limiting the available range of the various applications.
[0013] The present inventors conducted intensive studies and found that, in drying a solution of a hydrophilic modified polyrotaxane, a method in which the solution of the hydrophilic modified polyrotaxane is formed into a thin film state enables production of a dried hydrophilic modified polyrotaxane excellent in storage stability in an industrially advantageous way. Thus, the present invention was completed.
[0014] The method of producing a hydrophilic modified polyrotaxane of the present invention includes a hydrophilic modification step of preparing a solution of a hydrophilic modified polyrotaxane by modifying a polyrotaxane which includes a cyclodextrin, a polyethylene glycol included in the cavities of the cyclodextrin molecules in a skewered manner, and a capping group that is placed at each end of the polyethylene glycol and prevents dissociation of the cyclodextrin molecules from the polyethylene glycol, the modification of the polyrotaxane being performed by modifying all or part of hydroxy groups on the cyclodextrin with hydrophilic modifying groups. Through the hydrophilic modification step, the polyrotaxane is formed into a hydrophilic modified polyrotaxane soluble in water or a water-based solvent.
[0015] The polyrotaxane is typically produced through the following steps: an inclusion step where a polyethylene glycol having a reactive group at each end is mixed with a cyclodextrin in an aqueous medium to form an aqueous dispersion of a pseudopolyrotaxane, the aqueous dispersion containing pseudopolyrotaxane particles in which the polyethylene glycol is included in the cavities of the cyclodextrin molecules in a skewered manner; a drying step of the aqueous dispersion of a pseudopolyrotaxane to produce a solid of the pseudopolyrotaxane; and a capping step where the pseudopolyrotaxane is reacted with a compound that contains a capping group having a group reactive with the reactive group of the solid of the pseudopolyrotaxane, which introduces the capping group to each end of the polyethylene glycol included in the cavities of the cyclodextrin molecules.
[0016] The polyethylene glycol (hereinafter, also referred to as PEG) preferably has a weight average molecular weight of 1,000 to 500,000, more preferably 10,000 to 300,000, and still more preferably 10,000 to 100,000. A weight average molecular weight of the PEG of less than 1,000 may result in poor characteristics of a crosslinked polyrotaxane in which the resulting hydrophilic modified polyrotaxane is crosslinked. A weight average molecular weight of the PEG of more than 500,000 causes too high a viscosity of the solution of the polyrotaxane produced in the hydrophilic modification step, which may inhibit uniform reaction.
[0017] The weight average molecular weight herein is a polyethylene glycol equivalent value determined through measurement by gel permeation chromatography (GPC). A column used for determination of a polyethylene glycol equivalent weight average molecular weight by GPC is, for example, TSKgel SuperAWM-H (product of TOSOH CORPORATION).
[0018] The PEG may have a reactive group at each end, and the reactive group may be introduced by a conventional method.
[0019] The reactive group can be appropriately changed depending on the capping group to be used. Examples of the reactive group include, but not particularly limited to, hydroxy groups, amino groups, carboxyl groups, and thiol groups. A carboxyl group is particularly preferred. Examples of the method of introducing a carboxyl group at each end include a method of oxidizing each end using TEMPO (2,2,6,6-tetramethyl-l-piperidinyloxy radicals) and sodium hypochlorite.
[0020] In the inclusion step, the weight ratio between the PEG and the cyclodextrin is preferably 1:2 to 1:5, more preferably 1:2.5 to 1:4.5, and still more preferably 1:3 to 1:4. A weight of the cyclodextrin of less than twice the weight of the PEG may decrease the number (i.e. inclusion amount) of cyclodextrin molecules including the PEG. A weight of the cyclodextrin of more than five times the weight of the PEG does not increase the inclusion amount further, and thus is not economical.
[0021] Examples of the cyclodextrin include α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, and derivatives of these cyclodextrins. Particularly preferred in terms of inclusion property is α-cyclodextrin. These cyclodextrins may be used alone or in combination.
[0022] Examples of the aqueous medium include water, and aqueous mixtures of water and an aqueous organic solvent such as DMF and DMSO. Particularly, water is preferred.
[0023] The only required condition for mixing the PEG and the cyclodextrin in the inclusion step is mixing them in the above aqueous medium. Preferably, the PEG and the cyclodextrin are dissolved in the aqueous medium. Specifically, the PEG and the cyclodextrin are added to the aqueous medium and this pre-mixture is typically heated to 50° C. to 100° C., preferably 60° C. to 90° C., and more preferably 70° C. to 80° C., so that the components are dissolved in the aqueous medium. This provides a substantially transparent mixed solution.
[0024] Cooling the resulting mixed solution of the PEG and the cyclodextrin precipitates pseudopolyrotaxane particles of the PEG and the cyclodextrin, resulting in a basically white aqueous dispersion of the pseudopolyrotaxane.
[0025] The mixed solution is preferably cooled to an end-point temperature of 0° C. to 30° C., more preferably 1° C. to 20° C., and still more preferably 1° C. to 15° C. An end-point temperature of the mixed solution of lower than 0° C. may freeze the aqueous dispersion of a pseudopolyrotaxane to decrease the fluidity. An end-point temperature of the mixed solution of higher than 30° C. may not sufficiently precipitate pseudopolyrotaxane particles.
[0026] The time for retaining the flowing state of the resulting aqueous dispersion of a pseudopolyrotaxane after the mixed solution is cooled to a desired temperature is typically several seconds to one week, and preferably several hours to three days.
[0027] The pseudopolyrotaxane concentration of the aqueous dispersion of a pseudopolyrotaxane (hereinafter, also referred to as a “solids concentration of the aqueous dispersion of a pseudopolyrotaxane”) is preferably 5 to 25% by weight, more preferably 5 to 20% by weight, and still more preferably 10 to 20% by weight. A solids concentration of the aqueous dispersion of a pseudopolyrotaxane of lower than 5% by weight is not economical. A solids concentration of the aqueous dispersion of a pseudopolyrotaxane of higher than 25% by weight may decrease the fluidity of the aqueous dispersion of a pseudopolyrotaxane, causing difficulty in drying the dispersion.
[0028] In the drying step, the drying temperature for the aqueous dispersion of a pseudopolyrotaxane is preferably 70° C. to 200° C., more preferably 70° C. to 180° C., and still more preferably 70° C. to 170° C. A drying temperature for the aqueous dispersion of a pseudopolyrotaxane of lower than 70° C. in the drying step may cause insufficient drying. A drying temperature for the aqueous dispersion of a pseudopolyrotaxane of higher than 200° C. in the drying step may cause decomposition of the pseudopolyrotaxane, possibly decreasing the inclusion ratio which is described later.
[0029] The capping step may be carried out by a conventional method, and in terms of the reactivity and the stability of chemical bonding, particularly preferred is a capping method of reacting a pseudopolyrotaxane having a carboxyl group at each end of the PEG with an adamantane amine or a salt thereof as a capping agent.
[0030] In the hydrophilic modification step, the hydroxy groups on a cyclodextrin of a polyrotaxane may be modified with hydrophilic modifying groups by a conventional method.
[0031] Specific examples of the hydrophilic modifying group include, but not particularly limited to, carboxyl groups, sulfonic acid groups, sulfuric acid ester groups, phosphoric acid ester groups, primary to tertiary amino groups, quaternary ammonium bases, and hydroxy alkyl groups. Preferred are hydroxy alkyl groups resulting from a reaction with a compound such as propylene oxide, in view of the diversity of the reaction in synthesis of a crosslinked polyrotaxane.
[0032] In the hydrophilic modification step, the hydroxy groups on a cyclodextrin of a polyrotaxane are modified with hydrophilic modifying groups by, for smooth reaction, dissolving the polyrotaxane in a solvent such as DMSO or an alkali aqueous solution and reacting the polyrotaxane with a compound having a hydrophilic modifying group. Particularly preferable solvent used in the hydrophilic modification step is an aqueous solution of sodium hydroxide.
[0033] For example, synthesis of a hydrophilic modified polyrotaxane through addition of propylene oxide is carried out as follows. A polyrotaxane is dissolved in an aqueous solution of sodium hydroxide. Propylene oxide is added thereto and the mixture is stirred for reaction at from room temperature to 50° C. for several hours to one day. Thereby, a substantially transparent aqueous solution of a hydrophilic modified polyrotaxane to which propylene oxide is added is obtained.
[0034] The concentration of the hydrophilic modified polyrotaxane in the solution of the hydrophilic modified polyrotaxane (hereinafter, also referred to as the solids concentration of the solution of the hydrophilic modified polyrotaxane) is preferably 5 to 25% by weight, more preferably 5 to 20% by weight, and still more preferably 5 to 15% by weight . A solids concentration of the solution of the hydrophilic modified polyrotaxane of lower than 5% by weight is not economical. A solids concentration thereof of higher than 25% by weight raises the viscosity of the solution of the hydrophilic modified polyrotaxane, which may cause difficultly in forming the solution into a thin film state in the drying step.
[0035] The present inventors also found that adding a metal chelator and/or an antioxidant to a solution of the hydrophilic modified polyrotaxane and then forming the mixture into a thin film state further effectively prevents decomposition of the hydrophilic modified polyrotaxane during the drying step and of the resulting dried hydrophilic modified polyrotaxane with time during storage.
[0036] Specific and preferable examples of the metal chelator include aminopolycarboxylic acid metal chelators such as ethylene diamine tetraacetic acid (EDTA), cyclohexane diamine tetraacetic acid (CDTA), nitrilotriacetic acid (NTA), triethylenetetraamine hexaacetic acid, iminodiacetic acid (IDA), diethylene triamine pentaacetic acid, N-(2-hydroxy ethyl)ethylene diamine triacetic acid, glycol ether diamine tetraacetic acid, L-glutamic acid diacetic acid, L-aspartic acid-N,N-diacetic acid, and a salt thereof. Preferable examples of the antioxidant include polyphenols such as rosmarinic acid (rosemary extract), catechin, epicatechin, gallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate, epigallocatechin gallate, epigallocatechin, tannic acid, gallotannin, ellagitannin, caffeic acid, dihydro caffeic acid, chlorogenic acid, isochlorogenic acid, gentisic acid, homogentisic acid, gallic acid, ellagic acid, rutin, quercetin, quercetagin, quercetagetin, gossypetin, anthocyanin, leucoanthocyanin, proanthocyanidin, and enocyanin.
[0037] The amount of the metal chelator is preferably 0.001 to 5% by weight, more preferably 0.005 to 2% by weight, and still more preferably 0.01 to 1% by weight, based on the weight of the hydrophilic modified polyrotaxane. The amount of the antioxidant is preferably 0. 001 to 5% by weight, more preferably 0.005 to 2% by weight, and still more preferably 0.01 to 1% by weight, based on the weight of the hydrophilic modified polyrotaxane. The metal chelator or the antioxidant in an amount of less than 0.001% by weight may not effectively improve the storage stability. The metal chelator or the antioxidant in an amount of more than 5% by weight does not further improve the intended effect, and thus is not economical.
[0038] The resulting solution of the hydrophilic modified polyrotaxane is purified by a conventional purification technique such as dialysis or reprecipitation. The purified product is then dried, thereby yielding a solid of the hydrophilic modified polyrotaxane.
[0039] The method of producing a dried hydrophilic modified polyrotaxane of the present invention includes a drying step in which the prepared solution of the hydrophilic modified polyrotaxane is formed into a thin film state and dried.
[0040] A hydrophilic modified polyrotaxane produced by a conventional method is decomposed with time during storage. This is presumably attributed to chain of a slight amount of oxyradicals generated by heating and the like. In contrast, in the method of producing a hydrophilic modified polyrotaxane of the present invention, a solution of the hydrophilic modified polyrotaxane is formed into a thin film state and momentary dried in a drying step. This enables to avoid excessive heating in the drying step and to lead to a short time of exposure to heat. This presumably prevents the generation of radicals in the drying step, and thereby significantly improves the storage stability.
[0041] The solution of the hydrophilic modified polyrotaxane is formed into a thin film state by a method such as spray coating, spin coating, or dip coating.
[0042] When the solution of the hydrophilic modified polyrotaxane is formed into a thin film state, the thickness of the thin film formed is preferably 0.1 to 2 mm, more preferably 0.1 to 1 mm, and still more preferably 0.1 to 0.5 mm. A thickness of the thin film formed of the hydrophilic modified polyrotaxane of smaller than 0.1 mm may decrease the yield per hour, which is not economical. A thickness of the thin film formed of the hydrophilic modified polyrotaxane of larger than 2 mm may result in insufficient drying.
[0043] The method for controlling the thickness of the thin film formed of the hydrophilic modified polyrotaxane depends on factors such as the type of dryer to be used. In the case of the drum dryer mentioned later, for example, the thickness may be appropriately controlled by changing conditions such as the drum interval, the drum rotation speed, and the feeding speed of the solution of the hydrophilic modified polyrotaxane.
[0044] Examples of the dryer used in the drying step include drum dryers and centrifugal thin film dryers. Especially, a drum dryer is preferred because the structure of the device is comparatively simple and easy to maintain.
[0045] In the case of a drum dryer, for example, the solution of the hydrophilic modified polyrotaxane is applied to the surface of a heated drum to be formed into a thin film state, and then promptly evaporated to dryness. The dried product is continuously scraped with a fixedly mounted knife while the drum makes one rotation, so that a dried hydrophilic modified polyrotaxane is obtained.
[0046] The drying temperature in the drying step is preferably 70 to 200° C., more preferably 90 to 180° C., and still more preferably 100 to 170° C. A drying temperature of lower than 70° C. may lead to insufficient drying. A drying temperature of higher than 200° C. may decompose the hydrophilic modified polyrotaxane to decrease the inclusion ratio.
[0047] The pressure in the dryer system in the drying step is not particularly limited, but is typically a pressure near an atmospheric pressure. Vacuum drying is also possible. Drying is preferably performed under a pressure equal to or lower than an atmospheric pressure.
[0048] The drying time of the thin film formed of the hydrophilic modified polyrotaxane is typically several seconds to several minutes, and for suppression of isolation of modified cyclodextrin molecules, it is preferably ten minutes or shorter, more preferably five minutes or shorter, and still more preferably two minutes or shorter. Too short a drying time of the thin film formed of the hydrophilic modified polyrotaxane leads to insufficient drying.
[0049] According to the method of producing a hydrophilic modified polyrotaxane of the present invention, the inclusion ratio of the resulting dried hydrophilic modified polyrotaxane can be 6 to 60%. An inclusion ratio of lower than 6% may not give a sufficient pulley effect to the resulting crosslinked hydrophilic modified polyrotaxane obtained by crosslinking the dried hydrophilic modified polyrotaxane. An inclusion ratio of higher than 60% may result in excessively dense arrangement of modified cyclodextrin molecules, which are cyclic molecules, so that the mobility of the modified cyclodextrin molecules decreases. In order to give an appropriate mobility and a higher inclusion ratio to the modified cyclodextrin molecules, the inclusion ratio is preferably 15 to 40%, and more preferably 20 to 30%.
[0050] The inclusion ratio herein refers to a ratio of the inclusion amount of cyclodextrin molecules including a PEG to the maximum inclusion amount of the cyclodextrin molecules for a PEG. The inclusion ratio is optionally controllable by changing the mixing ratio of the PEG to the cyclodextrin or the kind of aqueous medium. The maximum inclusion amount refers to the number of cyclodextrin molecules in the case of the close-packed state in which one cyclodextrin molecule includes two repeating units of the PEG.
[0051] The inclusion ratio can be measured by 1 H-NMR. Specifically, the inclusion ratio can be calculated by dissolving the polyrotaxane in DMSO-d 6 , subjecting the solution to measurement using an NMR measuring device (product of Varian Technologies Japan Ltd., “VARIAN Mercury-400BB”), and comparing the integrated value of cyclodextrin at 4 to 6 ppm and the integrated value of cyclodextrin and PEG at 3 to 4 ppm. The hydrophilic modified polyrotaxane is produced by modifying the hydroxy groups on a cyclodextrin of a polyrotaxane with hydrophilic modifying groups. Therefore, the inclusion ratio of the hydrophilic modified polyrotaxane is the same as the inclusion ratio of the polyrotaxane.
[0052] When the maximum number of the modifiable hydroxy groups of a cyclodextrin of a polyrotaxane is 1, the degree of modification of the resulting dried hydrophilic modified polyrotaxane by the method of producing a hydrophilic modified polyrotaxane of the present invention is preferably 0.1 or more, more preferably 0.2 or more, and still more preferably 0.4 or more. A degree of modification of the dried hydrophilic modified polyrotaxane of lower than 0.1 gives insufficient solubility to water or a water-based solvent, possibly generating fine insoluble matters.
[0053] The maximum number of the modifiable hydroxy groups of a cyclodextrin herein refers to the number of all the hydroxy groups included in the polyrotaxane before modification. The degree of modification herein refers to the ratio of the number of modified hydroxy groups to the number of all the hydroxy groups. The degree of modification of the dried hydrophilic modified polyrotaxane can be calculated by dissolving a solution of the dried hydrophilic modified polyrotaxane in DMSO-d 6 , subjecting the solution to measurement using an NMR measuring device (product of Varian Technologies Japan Ltd., “VARIAN Mercury-400BB”), and comparing the integrated value of hydroxy propyl groups at 0.7 to 1.3 ppm and the integrated value of cyclodextrin and hydroxy propyl groups at 4.2 to 6.2 ppm.
Advantageous Effects of Invention
[0054] The present invention provides a method of producing a dried hydrophilic modified polyrotaxane, which enables production of a dried hydrophilic modified polyrotaxane excellent in storage stability in an industrially advantageous way.
DESCRIPTION OF EMBODIMENTS
[0055] The present invention is described below in more detail based on examples which, however, are not intended to limit the scope of the present invention. In the following, a PEG having a carboxyl group at each end was produced by oxidation of a PEG in accordance with the method described in WO 05/052026 A.
EXAMPLE 1
(1) Preparation of PEG Having Carboxyl Group at Each End by TEMPO Oxidation of PEG
[0056] In a 200-L reaction vessel, 100 L of water was charged, and 10 kg of a PEG (weight average molecular weight: 35,000), 100 g of TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy radicals), and 1 kg of sodium bromide were dissolved therein. To the solution was added 5 L of a commercially available aqueous solution of sodium hypochlorite (effective chlorine concentration: 50), and the resulting mixture was stirred at room temperature for 30 minutes. An amount of 5 L of ethanol was added to decompose the excess of sodium hypochlorite and terminate the reaction.
[0057] Extraction separation using 50 L of methylene chloride was repeated three times to extract the components excepting mineral salts, and then methylene chloride was evaporated under vacuum. Thereby, 10 kg of a PEG having a carboxyl group at each end was obtained.
[0000] (2) Preparation of Aqueous Dispersion of Pseudopolyrotaxane Using α-cyclodextrin and PEG Having Carboxyl Group at Each End
[0058] An amount of 325 L of water was added to 10 kg of the prepared PEG having a carboxyl group at each end. Then, 40 kg of α-cyclodextrin was added to the mixture and the resulting mixture was heated to 70° C. for dissolution. The solution was cooled to 4° C. while being stirred, whereby a milky aqueous dispersion of a pseudopolyrotaxane was precipitated.
(3) Drying of Aqueous Dispersion of Pseudopolyrotaxane
[0059] Using a nozzle atomizer spray drier (product of Ohkawara Kakohki Co., Ltd., “L-8”), 400 kg of the prepared aqueous dispersion of a pseudopolyrotaxane was spray-dried at an inlet temperature of the spray dryer of 165° C. and an outlet temperature of 90° C. under ordinary pressure. Thereby, 50 kg of a powdered pseudopolyrotaxane was obtained.
(4) Capping of Pseudopolyrotaxane Using Adamantane Amine and BOP Reagent Reaction System
[0060] In a 500-L reaction vessel, 500 g of adamantane amine was dissolved in 170 L of dimethyl formamide (DMF) at room temperature. Then, 50 kg of the powdered pseudopolyrotaxane was added to the vessel and the mixture was stirred. Subsequently, a solution in which 1.3 kg of a BOP reagent (benzotriazol-1-yl-oxy-tris (dimethylamino) phosphonium hexafluorophosphate) was dissolved in 80 L of DMF was added to the vessel, and the mixture was stirred. To the vessel was further added a solution in which 500 mL of diisopropylethylamine was dissolved in 80 L of DMF, and the mixture was stirred at normal temperature overnight.
[0061] The resulting mixture was filtered. To the residue was added 300 L of hot water (70° C.) , the mixture was stirred well, and the resulting mixture was filtered. This process was repeated three times. The resulting residue was vacuum-dried, and thereby 30 kg of purified polyrotaxane was obtained in the end.
(5) Hydroxypropylation of Hydroxy Groups of Cyclodextrin
[0062] To a 500-L reaction vessel, 180 L of water, 10 kg of sodium hydroxide, and 30 kg of the purified polyrotaxane were dissolved. To the solution was added 60 kg of propylene oxide and the mixture was stirred at room temperature under a nitrogen atmosphere overnight. The resulting mixture was neutralized with a 1 mol/L aqueous solution of HCl. Then, the mixture was diluted with water for purification, thereby yielding 400 kg of an aqueous solution of the hydrophilic modified polyrotaxane with a solids concentration of 10% by weight.
(6) Drying of Aqueous Solution of Hydrophilic Modified Polyrotaxane
[0063] The prepared aqueous solution of the hydrophilic modified polyrotaxane (60 kg) was dried in a double drum dryer (product of Katsuragi Industry Co., Ltd., type: D-0303) at a drum surface temperature of 120° C. and a drum rotation speed of 1 rpm (drying time: 40 sec) . In the drying, the solution of the hydrophilic modified polyrotaxane was applied to the drum to be formed into a thin film state with a thickness of 0.5 mm. The dried product is continuously scraped with a fixedly mounted knife, thereby obtaining 6.2 kg of a dried hydrophilic modified polyrotaxane (drying loss: 2.8% by weight) . The resulting dried hydrophilic modified polyrotaxane had an inclusion ratio of 27%, and no free modified cyclodextrin was detected. The resulting dried hydrophilic modified polyrotaxane had a degree of modification of 0.5.
[0064] The free modified cyclodextrin content refers to a weight percent ratio of the free modified cyclodextrin content to the dried hydrophilic modified polyrotaxane, and can be calculated from the following formula.
[0065] Free modified cyclodextrin content [%]=(weight of free modified cyclodextrin molecules in dried hydrophilic modified polyrotaxane/weight of dried hydrophilic modified polyrotaxane)×100
[0066] The weight of the free modified cyclodextrin molecules in the dried hydrophilic modified polyrotaxane was determined by the absolute calibration method of liquid chromatograph analysis.
[0067] The determination was carried out using a high-performance liquid chromatograph (product of Waters Corporation, “Alliance 2695”).
EXAMPLE 2
[0068] A hydrophilic modified polyrotaxane in an amount of 6.0 kg (drying loss: 1.8% by weight) was obtained in the same manner as in Example 1 except that, in drying of the aqueous solution of the hydrophilic modified polyrotaxane, the drum surface temperature was changed to 180° C. and the drum rotation speed was changed to 2 rpm (drying time: 20 sec). In the drying, the thickness of the thin film formed of the hydrophilic modified polyrotaxane applied to the drum was 0.3 mm. According to the same measurements as in Example 1, the resulting dried hydrophilic modified polyrotaxane had an inclusion ratio of 23%, a free modified cyclodextrin content of 0.1% by weight, and a degree of modification of 0.5.
EXAMPLE 3
[0069] A hydrophilic modified polyrotaxane in an amount of 6.0 kg (drying loss: 4.0% by weight) was obtained in the same manner as in Example 1 except that, in drying of the aqueous solution of the hydrophilic modified polyrotaxane, the drum surface temperature was changed to 90° C. and the drum rotation speed was changed to 0.5 rpm (drying time: 80 sec). In the drying, the thickness of the thin film formed of the hydrophilic modified polyrotaxane applied to the drum was 0.1 mm. According to the same measurements as in Example 1, the resulting dried hydrophilic modified polyrotaxane had an inclusion ratio of 28%, and no free modified cyclodextrin was detected. The degree of modification was 0.5.
EXAMPLE 4
[0070] A hydrophilic modified polyrotaxane in an amount of 6.0 kg (drying loss: 2.8% by weight) was obtained in the same manner as in Example 1 except that, in drying of the aqueous solution of the hydrophilic modified polyrotaxane, rosmarinic acid (rosemary extract, product of Mitsubishi-Kagaku Foods Corporation, “RM-21 Base”) in an amount of 0.01% by weight based on the weight of the hydrophilic modified polyrotaxane was added before drying was carried out in a double drum dryer. In the drying, the thickness of the thin film formed of the hydrophilic modified polyrotaxane applied to the drum was 0.5 mm. According to the same measurements as in Example 1, the resulting dried hydrophilic modified polyrotaxane had an inclusion ratio of 28%, and no free modified cyclodextrin was detected. The degree of modification was 0.5.
EXAMPLE 5
[0071] A hydrophilic modified polyrotaxane in an amount of 6.0 kg (drying loss: 2.8% by weight) was obtained in the same manner as in Example 1 except that, in drying of the aqueous solution of the hydrophilic modified polyrotaxane, gallic acid in an amount of 0.01% by weight based on the hydrophilic modified polyrotaxane was added before drying was carried out in a double drum dryer. In the drying, the thickness of the thin film formed of the hydrophilic modified polyrotaxane applied to the drum was 0.5 mm. According to the same measurements as in Example 1, the resulting dried hydrophilic modified polyrotaxane had an inclusion ratio of 28%, and no free modified cyclodextrin was detected. The degree of modification was 0.5.
EXAMPLE 6
[0072] A hydrophilic modified polyrotaxane in an amount of 6.0 kg (drying loss: 2.8% by weight) was obtained in the same manner as in Example 1 except that, in drying of the aqueous solution of the hydrophilic modified polyrotaxane, EDTA in an amount of 0.01% by weight based on the weight of the hydrophilic modified polyrotaxane was added before drying was carried out in a double drum dryer. In the drying, the thickness of the thin film formed of the hydrophilic modified polyrotaxane applied to the drum was 0.5 mm. According to the same measurements as in Example 1, the resulting dried hydrophilic modified polyrotaxane had an inclusion ratio of 28%, and no free modified cyclodextrin was detected. The degree of modification was 0.5.
EXAMPLE 7
[0073] A hydrophilic modified polyrotaxane in an amount of 6.0 kg (drying loss: 2.8% by weight) was obtained in the same manner as in Example 1 except that, in drying of the aqueous solution of the hydrophilic modified polyrotaxane, diethylene triamine pentaacetic acid in an amount of 0.01% by weight based on the weight of the hydrophilic modified polyrotaxane was added before drying was carried out in a double drum dryer. In the drying, the thickness of the thin film formed of the hydrophilic modified polyrotaxane applied to the drum was 0.5 mm. According to the same measurements as in Example 1, the resulting dried hydrophilic modified polyrotaxane had an inclusion ratio of 28%, and no free modified cyclodextrin was detected. The degree of modification was 0.5.
COMPARATIVE EXAMPLE 1
[0074] An aggregated hydrophilic modified polyrotaxane in an amount of 95 g (drying loss: 5% by weight) was obtained in the same manner as in Example 1, except that, in drying the aqueous solution of the hydrophilic modified polyrotaxane, 1 kg of the aqueous solution of the hydrophilic modified polyrotaxane was freeze-dried (dried at −10° C. to 20° C. for 48 hours). According to the same measurements as in Example 1, the resulting aggregated hydrophilic modified polyrotaxane had an inclusion ratio of 23% and a free modified cyclodextrin content of 0.1% by weight. The degree of modification of the aggregated hydrophilic modified polyrotaxane was 0.5.
COMPARATIVE EXAMPLE 2
[0075] An aggregated hydrophilic modified polyrotaxane in an amount of 94 g (drying loss: 4% by weight) was obtained in the same manner as in Example 1, except that, in drying the aqueous solution of the hydrophilic modified polyrotaxane, 1 kg of the aqueous solution of the hydrophilic modified polyrotaxane was vacuum-dried at 20° C. for 96 hours using a vacuum dryer. According to the same measurements as in Example 1, the resulting aggregated hydrophilic modified polyrotaxane had an inclusion ratio of 23%, a free modified cyclodextrin content of 1.5% by weight, and a degree of modification of 0.5.
COMPARATIVE EXAMPLE 3
[0076] An aggregated hydrophilic modified polyrotaxane in an amount of 94 g (drying loss: 3% by weight) was obtained in the same manner as in Example 1, except that, in drying the aqueous solution of the hydrophilic modified polyrotaxane, 1 kg of the aqueous solution of the hydrophilic modified polyrotaxane was vacuum-dried at 60° C. for 48 hours using a vacuum dryer. According to the same measurements as in Example 1, the resulting aggregated hydrophilic modified polyrotaxane had an inclusion ratio of 23%, a free modified cyclodextrin content of 2% by weight, and a degree of modification of 0.5.
COMPARATIVE EXAMPLE 4
[0077] An aggregated hydrophilic modified polyrotaxane in an amount of 94 g (drying loss: 2% by weight) was obtained in the same manner as in Example 1, except that, in drying the aqueous solution of the hydrophilic modified polyrotaxane, 1 kg of the aqueous solution of the hydrophilic modified polyrotaxane was dried at 60° C. for 24 hours under an atmospheric pressure in a hot-gas dryer. According to the same measurements as in Example 1, the resulting aggregated hydrophilic modified polyrotaxane had an inclusion ratio of 23%, a free modified cyclodextrin content of 48% by weight, and a degree of modification of 0.5.
<Evaluation>
[0078] Each hydrophilic modified polyrotaxane obtained in the examples and comparative examples was stored in a 40° C. thermostatic bath. The free modified cyclodextrin content was measured on the 30th and 120th days by a high-performance liquid chromatograph (product of Waters Corporation, “Alliance 2695”). Table 1 shows the results and the values measured immediately after the production.
[0000]
TABLE 1
Immediately after
production
Day 30
Day 120
Example 1
Not detected
2%
by weight
5%
by weight
Example 2
0.1%
by weight
3%
by weight
8%
by weight
Example 3
Not detected
1%
by weight
2%
by weight
Example 4
Not detected
0.4%
by weight
0.8%
by weight
Example 5
Not detected
0.4%
by weight
0.8%
by weight
Example 6
Not detected
0.8%
by weight
1.5%
by weight
Example 7
Not detected
0.6%
by weight
1.2%
by weight
Comparative
0.1%
by weight
3%
by weight
11%
by weight
Example 1
Comparative
1.5%
by weight
8%
by weight
17%
by weight
Example 2
Comparative
2%
by weight
22%
by weight
42%
by weight
Example 3
Comparative
48%
by weight
85%
by weight
90%
by weight
Example 4
INDUSTRIAL APPLICABILITY
[0079] The present invention provides a method of producing a hydrophilic modified polyrotaxane, which enables production of a dried hydrophilic modified polyrotaxane excellent in storage stability in an industrially advantageous way.
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The present invention aims to provide a method of producing a hydrophilic modified polyrotaxane, which enables production of a hydrophilic modified polyrotaxane excellent in storage stability in an industrially advantageous way. The present invention provides a method of producing a hydrophilic modified polyrotaxane, comprising: a hydrophilic modification step of preparing a solution of a hydrophilic modified polyrotaxane by modifying all or part of hydroxy groups on a cyclodextrin of a polyrotaxane with hydrophilic modifying groups, the polyrotaxane containing the cyclodextrin, a polyethylene glycol included in the cavities of the cyclodextrin molecules in a skewered manner, and a capping group that is placed at each end of the polyethylene glycol and prevents dissociation of the cyclodextrin molecules from the polyethylene glycol; and a drying step in which the prepared solution of the hydrophilic modified polyrotaxane is formed into a thin film state and dried.
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This invention relates to a muffler which is suitable for use on a motor vehicle although it may also be used in other applications of silencing a fluid flow, for example water lines or air conditioning ducts. It also relates to a muffler of the type having a perforate tube which extends through an otherwise sealed chamber, thereby constituting a Helmholtz resonator.
BACKGROUND OF THE INVENTION
It is common practice to use perforate or slotted tubes in Helmholtz resonator mufflers, as well as in some sections of more complex mufflers, but owing to the tendency for a perforation or slot to cause whistling (noises at about 1000 Hz or more), it has heretofore usually been deemed necessary to have louvres formed in the tubes. This causes secondary difficulties however, in that the louvres are formed outwardly or inwardly or both by lancing and stretching small areas of the tube wall. This operation is usually achieved in a press, the tube either being formed by firstly lancing and subsequent rolling the workpiece, or forming a tube in imperforate form and subsequently lancing the louvres in the tube wall. In the first case the resultant tube has a bead joining its edges, and is usually non-circular and quite unsuitable for accurate fitting to the skirts on the ends of a muffler housing or accurate fitting to a properly rounded tube. Furthermore, in both cases, outstanding louvre edges prevent the tube from being driven through a preformed muffler housing or preformed internal baffle, and inwardly facing louvre edges prevent a close-fitting tube being placed inside the louvred tube.
The main object of this invention is to provide improvements whereby a perforate or slotted tube can be employed, without the need for louvres.
BRIEF SUMMARY OF THE INVENTION
In this invention a muffler of the Helmholtz resonator type has a housing surrounding a main gas flow conduit, the gas flow conduit having an apertured zone within the housing wherein apertures extend through the conduit wall, the shape of the conduit wall at the apertured zone being so varied that gas flows through the apertures into or out of the housing the flow inhibiting the development of whistle noises.
Specifically, the invention consists of a muffler having a main gas flow conduit and a surrounding housing defining a muffler space between the main gas flow conduit and the housing, an apertured zone extending along part at least of said conduit wall within the muffler housing wherein apertures through the conduit wall provide gas flow passages between the space within the conduit and the muffler space, the shape of the conduit wall so varying in the apertured zone that when gas flows through said conduit, some of said gas also flows from the conduit space into the muffler space through some of said apertures, and from the muffler space back into the conduit space through others of said apertures.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Several embodiments of the invention are described hereunder in some detail with reference to and are illustrated in the accompanying drawings in which:
FIG. 1 is a longitudinal section through a muffler of the Helmholtz resonator type wherein the muffler conduit is a cross-sectional area, which varies within a muffler housing.
FIG. 2 is a cross-section taken on line 2--2 of FIG. 1,
FIG. 3 shows an alternative arrangement wherein the muffler housing is itself a sleeve the inner wall surface or which is contiguous with the outer wall surface of the muffler conduit,
FIG. 4 shows a third embodiment wherein the muffler conduit is expanded within a housing,
FIG. 5 shows a fourth embodiment wherein the muffler conduit varies in cross-sectional area, and
FIG. 6 shows a fifth embodiment wherein the muffler conduit has a constant cross-sectional area but varies in shape alone.
Referring first to the embodiment of FIGS. 1 and 2, a muffler 10 is provided with a main gas flow conduit 11 and a housing 12 defining a muffler space 13 surrounding the main gas flow conduit 11. The housing 12 includes end plates 14 and 15, and stiffeners 16 which themselves contain large apertures 17, thereby, with the conduit 11, defining a Helmholtz resonator.
As shown in FIG. 2, the wall of the main gas flow conduit 11 is deformed to a "figure 8" shape by having two depressions 18 and 19 opposite one another, and this formation enables the tube to be inserted through openings, for example in stiffeners 16 and 17 or the end plates 14 and 15. In this embodiment, not only is the shape varied, but there is a consequential variation in the cross-sectional area, and at the locality of the section line 2--2, the flow area through the conduit 11 is reduced, thereby forming a throat 20.
Both upstream and downstream of the throat 20, and at the locality of the throat 20, the wall of the conduit has a plurality of apertures 25 therein, and these allow gas flows A, B and C through the apertures 25 and through the muffler space 13.
Within the conduit 11, there is a variation of static or wall pressure and this pressure is lower at the throat than at either of the upstream or downstream ends, because of the higher velocity of flow through the throat. The flow A will occur because of the difference in wall pressure, regardless of whether there is any difference in stagnation pressure upstream and downstream of the throat 20, that is, regardless of whether there is any back pressure in the main flow. The flow B will at most be nearly the same as the flow A in the event of zero stagnation pressure difference, that is, in the event of zero back pressure for the main flow. However, for decreasing amounts of pressure recovery for the main flow beyond the throat 20, the flow B eventually reduces to zero. However, with this form of variation in section, some back pressure is essentially developed, and the flow C is due to this back pressure or stagnation pressure upstream and downstream of the throat. The apertures 25 of course give gas flow access to the Helmholtz resonator defined by the muffler housing 12, and this access is provided without any whistling because of the existence of the flows A, B and C. In the absence of area variation in the main conduit 11, flows A, B and C do not exist and whistles may occur through the phenomenon of edge tones.
In the embodiment of FIG. 3, the housing is designated 27 and is merely a sleeve which passes over a portion of the main flow conduit 28, the main flow conduit 28 having a deformed reduced diameter portion 29 which constitutes a throat. The shape of the deformed portion 29 is not critical to the invention and the throat may be circular, or for example, as shown in FIG. 2. In this embodiment, the apertures 30 are upstream and downstream of the throat 29, and the flows A, B and C exist to some degree within the muffler space 31.
The embodiment of FIG. 4 is similar to that of FIG. 3 as far as the flows A, B and C are concerned, excepting that instead of having a throat 29, the main flow conduit 35 has an expanded portion 36 within the muffler housing 37, and the ends of the expanded portion 36 as well as the portion 36 itself contain apertures 38 through which the flows A, B and C, occur. It will be noted that the flows A and B are in opposite directions from the flows which occur in the FIG. 3 embodiment. In the case of the flow in FIG. 4 the highest wall pressure is at B in the expanded portion 36.
In the embodiment of FIG. 5 (which illustrates only the main flow of conduit 40, since the shape of the muffler housing is inconsequential to this invention), the main flow conduit 40 at its upstream end 41 is larger than at its downstream end 42, but the two portions are interconnected by a converging wall portion 43, the angular slope of which is not critical and may vary over a large range. The only flow in this case is a flow A, the flow being caused by the difference in wall pressure caused by the increase in velocity of gases as they enter the downstream end 42.
In all the above embodiments, the shape of the conduit wall varies in such a way as to vary the cross-sectional area. However, this is not necessary, and in the embodiment of FIG. 6 the cross-sectional area remains constant. However, the main flow conduit 45 (again illustrated without the muffler housing) is provided with apertures 46 throughout its length, and is provided with a spiral groove 47 which forms an inwardly directed helical lobe 48, such that the cross-sectional shape continuously varies but the area does not. The gas flow will be faster over the lobes of the spiral, and this will cause a static pressure drop which will cause A and B flows as shown, but the amount of stagnation pressure drop can be small and the use of this type of main flow conduit will not result in high back pressure and the C type flow will not occur to a great extent.
With this invention, the area variation of the conduit shape may be such that a large decrease of stagnation pressure (that is, a large amount of back pressure in the main flow) is not essential to cause a significant average gas flow through the apertures and the structure dimensions can be such that whistling does not occur. With some alternative designs, whistling occurs through the edge-tone phenomenon.
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A muffler of the Helmholtz resonator type has a housing surrounding a main gas flow conduit, the gas flow conduit having an apertured zone within the housing wherein apertures extend through the conduit wall, the shape of the conduit wall at the apertured zone being so varied that gas flows through the apertures into or out of the housing, the flow inhibiting the development of whistle noises.
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CROSS REFERENCE TO RELATED APPLICATION
This patent application claims the benefit of application Ser. No. 08/490,106, now U.S. Pat. No. 5,712,905, filed on Jun. 8, 1995.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed in general to a system for processing analog signals, and more particularly to a system which employs sequential digital profiles to detect analog signals (or fragments of analog signals) satisfying requirements represented by said sequential digital profiles.
2. Description of the Background Art
Due to the real-time performance and storage requirement, recent demands for processing of on-line analog signal in such diversity of emerging applications as smart cards, signature identification, data security, speech recognition, medical diagnosis, and other transaction-oriented applications have required novel methods to be explored and introduced for the effective on-line computation of incoming analog signals. Namely for these new emerging transaction-oriented application the signal channels would typically remain silent until selective authorized users have made and initiated a particular request for the channel usage. The incoming signal sequence will then be comprised of selective user identification code, follow with a sequence of commands, and their relevant data. Due to their nature, such transactions can happen at any of the time instances, and occur in a totally random fashion. Therefore, it is really not possible to predict, anticipate and schedule these events employing traditional scheduling, optimization, and computation methods as described in the background arts.
As a result, although there are plenty of background arts for example, Oppenheim A. V. and chafer, R. W. “Digital Signal Processing”, Printice Hall, 1975, and Kung S., “VLSI Processor Array”, Prentice Hall 1987, which taught methods for the on-line processing of analog signal data, all of the methods would first require the traditional signal conversion from analog to digital domain, then store the entire command and data content at a local storage, and finally execute the commands when the user identifications are validated. These methods, though practical, require expensive high speed processing and memory circuits in order to reach the real time performance. Furthermore, these circuits must be constantly active in order to continuously monitor the signal channel for any incoming signal sequence. Finally, none of these methods have ever taught how to discriminate and eliminate the unauthorized or uninterested signals in the analog domain, namely prior to the analog to digital signal conversion, in order to avoid further storage and processing at the digital domain. It is conceived that these background arts will impose serious cost and power consumption disadvantage for their product implementation, and subsequently limit the market realization potential of these emerging technologies and applications.
In the relevant field of cryptography, similar situation remains. Although there are plenty of background arts which have taught how to apply highly sophisticated mathematical techniques and high speed scientific computer in order to generate the stored security key and to further encrypt the entire signal sequence. For example, Kahn B, Feiertag in “Private Communications in Mode Secure Systems” 1989, and Man Y. R. in “Cryptography and Secure Communications”, McGraw Hill, 1994. However, it is extremely difficult to accomplish real time on-line decryption without depending on vector or parallel computing. The situation becomes worse, particularly when use of multiple analog waveform representation for encryption further demands multiple algorithms and computation.
In light of these storage and performance problems, prior to their conversion from analog to digital domain, some form of novel front-end-computation method for the online analog signals is necessary. It would be also necessary to make such method programmable, whereby a single device can be programed in order to adapt to the various application environments. Finally, it is further necessary to make such computation method simple yet effective so that the product realization can become economical and affordable at the marketplace. To date, no single device possesses the necessary computation and storage power, yet would only require nominal cost for its implementation, in order to process the incoming analog bitstream at the necessary real time performance.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a system method for processing selective analog signals prior to their conversion from analog to digital domain, and more particularly a system method which employs sequential digital profiles to process incoming analog signals in order to detect signals (or fragments of signals) satisfying requirements represented by said sequential digital profiles.
It is still further an object of the present invention to apply said system method for the encryption and decryption of selective analog signals for privileged communications, wherein said decryption can be performed in real time prior to the signal conversion from analog to digital domain.
It is still further an object of the present invention to generalize said analog signals for including time-domain analog signals representing selective physical phenomena.
It is still further an object of the present invention to determine rules, conditions, and algorithms for the development of said sequential digital profiles.
It is still further an object of the present invention to perform on-line segmentation of said incoming analog signals according to selective properties of said sequential digital profiles.
It is still further an object of the present invention to represent results of said segmentation through on-line computation of a sequence of measurements in accordance with selective properties of said sequential digital profiles.
It is still further an object of the present invention to compare said results of segmentation with said sequential digital profiles in order to detect said incoming signals (or fragments of said incoming signals) satisfying requirements represented by said sequential digital profiles.
A preferred embodiment of the present invention is a system incorporating an input device, a memory device, a control unit, and a processing unit.
The input device acquires incoming analog signals. The memory device contains predefined sequential digital profiles. A single sequencial digital profile consists of the following components:
(i) a sequence of samples consisting of two values: a lower threshold value and a higher threshold value (the range of a sample);
(ii) a list of attributes divided into two subsets: in-segment attributes and off-segment attributes;
(iii) attribute values of said list of attributes for each sample of said sequence of samples.
The control unit supervises other components of the system according to a control algorithm, and interprets the results received from the processing unit. The general idea of the control algorithm performed by control unit is as follows:
(i) activate receiving an incoming analog signal by the input device;
(ii) activate a selected sequential digital profile;
(iii) send to the processing unit said list of attributes (both off-segment attributes and insegment attributes) of the active sequential digital profile;
(iv) select the first sample from said sequence of samples of the active sequential digital profile;
(v) send to the processing unit said range of the selected sample;
(vi) wait until attribute measurements are received from the processing unit;
(vii) if the received attribute measurements do not match said attribute values of the selected sample go to (iv);
(viii) if the selected sample is the last sample of said sequence of samples of the active sequential digital profile then either
assume that the incoming analog signal satisfies requirements represented by the active sequential digital profile and quit the algorithm
or
assume that the current fragment of the incoming analog signal satisfies requirements of the active sequential digital profile and go to (ii);
(ix) select the next sample of said sequence of samples and go to (v).
The algorithm can be interrupted or suspended at any moment when no incoming analog signal is available from the input device.
The processing unit performs selective operations on said incoming analog signals. This includes on-line attribute measurements according to the list of attributes received from the control unit, and on-line segmentation according to the range thresholds received from the control unit. The general idea of the operations performed by the processing unit is as follows:
(i) perform on-line computation of attribute measurements for said of off-segment attributes received from the control unit, until the magnitude of the incoming signal is within said range received from the control unit (detecting the beginning of a segment);
(ii) perform on-line computation of attribute measurements for said in-segment attributes received from the control unit, until the magnitude of the incoming signal quits said range received from the control (detecting the end of a segment);
(iii) send the computed attribute measurements to the control unit and go to (i).
It is envisaged that in the practical applications of the invention selected steps of both above-mentioned algorithms can be performed parallelly and/or asynchronously in order to minimize delays and avoid discontinuities in processing the incoming analog signals.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention and wherein:
FIG. 1 is a general block diagram illustrating major components and data flow in a preferred embodiment of the present invention.
FIG. 2 shows a general structure of sequential digital profiles.
FIG. 3 shows a general structure of the processing unit.
FIG. 4 is a flowchart illustrating in a broad sense the steps of the algorithm performed in the control unit of the preferred embodiment of the present invention.
FIG. 5 is a flowchart illustrating in a broad sense the steps of the algorithm performed in the processing unit of the preferred embodiment of the present invention.
FIG. 6 shows an example of a sequential digital profile according to the general structure of FIG. 2 .
FIG. 7 shows an example of the processing unit which can perform computation of attribute measurements required for the sequential digital profile of FIG. 6 .
FIGS. 8 to 11 show examples of incoming analog signals and results of the processing performed by the algorithm of FIG. 4 using processing unit of FIG. 7 and the sequential digital profile of FIG. 6 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the following description, particular reference is made to the implementation of the invention in the context of processing voltage signals. It is envisaged, however, that the practical applications of the invention can be extended to many other areas in which selective physical phenomena would be represented by the analog, time-domain signals.
Referring to FIG. 1, the preferred system in which the present invention would be applied consists of the input device 11 , the processing unit 12 , the control unit 13 . and the memory device 14
Incoming analog signals 20 are acquired from the input device 11 , which is capable to capture continuously the magnitude of the signals. Acquisition of an incoming signal is activated by the signal 21 received from the control unit 13 . The incoming signal 20 will be denotes as X(t). The signal 22 is to inform the control unit that no incoming signal is being received. Usually this should suspend or interrupt the control algorithm run by the control unit 13 .
The incoming signal 20 is processed in the processing unit 12 according to the list of attributes 60 , and the range 50 received from the control unit 13 . This includes extraction of continuous segments of the incoming signal 20 being within the range 50 , as well as computation of attribute measurements 30 according to the attributes 60 . The processing unit 12 is equipped with the devices capable to perform the required computation on-line. The computed attribute measurements 30 are send to the control unit 13 .
The control unit 13 runs a control algorithm, and interprets the attribute measurements 30 received from the processing unit 12 . This includes activation of selected sequential digital profiles 25 from the profiles stored in the memory device 14 . The active sequential digital profile 25 is retrieved from the memory device 14 . The list of attributes 60 and the range 50 which are being send to processing 12 are extracted from the active sequential digital profile 25 .
Referring to FIG. 2, sequential digital profiles 25 stored in the memory device 14 consist of the following components:
(i) the sequence of samples 40 {S 1 , S 2 , . . . , Sn} wherein each sample Si (i=1, . . . ,n) has its range 50 bounded by the higher threshold value HTi ( 51 ) and the lower threshold value LIi ( 52 );
(ii) the list of attributes 60 consisting of off-segment attributes 61 {OFA 1 , OFA 2 , . . . , OFA v } and in-segment attributes 62 {INA 1 , INA 2 , . . . , INA w };
(iii) for each sample Si (i=1, . . . ,n), the sequence of off-segment attribute values 63 {OFA 1 (Si), OFA 2 (Si), . . . , OFA v (Si)};
(iv) for each sample Si (i=1, . . . ,n), the sequence of in-segment attribute values 64 {INA 1 (Si), INA 2 (Si), . . . , INA w (Si)}.
Referring to FIG. 3, a general structure of the processing unit 12 comprises the following components:
the modules 121 performing on-line computation of off-segment attribute measurements 33 for all off-segment attributes which can appear in sequential digital profiles stored in the memory device 14 ;
the modules 122 performing on-line computation of in-segment attribute measurements 34 for all in-segment attributes which can appear in sequential digital profiles stored in the memory device 14 ;
the threshold buffers 123 and 124 containing the higher threshold value 51 and the lower threshold value 52 respectively;
the range selector 125 detecting whether the current magnitude of the incoming signal 20 is within the range defined by the thresholds 51 and 52 received from the buffers 123 and 124 respectively;
the attribute buffer 126 activating (using CS signals 136 ) selected said modules 121 according to the list of off-segment attributes 61 ;
the attribute buffer 127 activating (using CS signals 137 ) selected said modules 122 according to the list of in-segment attributes 62 ;
the measurement memory 130 (consisting of the off-segment buffer 131 and the in-segment buffer 132 ) memorizing the attribute measurements 30 comprising the off-segment attribute measurements 33 and the in-segment attribute measurements 34 , wherein the off-segment attribute measurements 33 are received from the modules 121 and memorized in the buffer 131 , while the in-segment attribute measurements 34 are received from the modules 122 and memorized in the buffer 132 .
The reset signals 141 and the load signal 151 are arranged so that the off-segment attribute measurements 33 are computed when the incoming signal 20 is outside the range defined by the thresholds 51 and 52 , and said measurements are memorized in the buffer 131 when the incoming signal 20 enters said range.
The reset signals 142 and the load signal 152 are arranged so that the in-segment attribute measurements 34 are computed when the incoming signal 20 is within the range defined by the thresholds 51 and 52 , and said measurements are memorized in the buffer 132 when the incoming signal 20 quits said range.
Referring to FIG. 4, the algorithm performed in the control unit 13 comprises the following steps:
Step 100 Send the signal 21 to initialize acquisition of an incoming analog signal 20 X(t) from the input device 11 .
Step 101 Select an active sequential digital profile 25 , and retrieve it from the memory device 14 .
Step 102 Send the list of attributes 60 of the active sequential digital profile 25 to the buffers 126 and 127 of the processing unit 12 .
Step 103 Set i=1.
Step 104 Select the sample Si from the sequence of samples 40 of the active sequential digital profile 25 .
Step 105 For the selected sample Si, send the higher threshold value HTi ( 51 ) and the lower threshold value LTi ( 52 ) to the buffers 123 and 124 of the processing unit 12 .
Step 106 Wait until the attribute measurements 33 {MeOFA 1 , MeOFA 2 , . . . , MeOFA v } (corresponding to the off-segment attributes 61 {OFA 1 , OFA 2 , . . . , OFA c }) and the attribute measurements 34 {MeINA 1 , MeINA 2 , . . . , MeINA w } (corresponding to the in-segment attributes 62 {INA 1 , INA 2 , . . . , INA w }) are received from the buffers 131 and 132 of the processing unit 12 .
Step 107 If
{MeOFA 1 , MeOFA 2 , . . . , MeOFA v }≠{OFA 1 (Si), OFA 2 (Si), . . . , OFAv(Si)}
or
{MeINA 1 , MeINA 2 , . . . , MeINA w }≠{INA 1 (Si), INA 2 (Si), . . . , INA w (Si)}
goto Step 103 .
Step 108 If (i<n) then
i=i+1; goto Step 104
Step 109 If more sequential digital profiles required then
accept the received fragment of the signal X(t); goto Step 101 else
accept the received signal X(t); exit.
The algorithm can be suspended or terminated at any moment when the signal 22 is received from the processing unit 12 , i.e. when no incoming signal 20 is available.
The abovementioned algorithm is given by way of illustration and example only and is not to be taken by way of limitation, so that in the future embodiments other algorithms based on the same principles could be applied. In particular, selected steps of the algorithm can be performed parallelly, asynchronously or can be pipelined in order to minimize delays and avoid discontinuities in processing the incoming analog signal 20 .
Referring to FIG. 5, the algorithm performed in the processing unit 12 has the following structure:
Step 200 Perform on-line computation of off-segment attribute measurements 33 using modules 121 selected according to the content of the buffer 126 until the magnitude of X(t) is inside the range defined by the content of the threshold buffers 123 and 124 .
Step 201 Memorize said measurements 33 of Step 200 in the measurement buffer 131 , and reset the modules 122 selected according to the content of the buffer 127 .
Step 202 Perform on-line computation of in-segment attribute measurements 34 using modules 122 selected according to the content of the buffer 127 until the magnitude of X(t) is outside the range defined by the content of the threshold buffers 123 and 124 .
Step 203 Memorize said measurements 34 of Step 202 in the measurement buffer 132 , and reset the modules 121 selected according to the content of the buffer 126 .
Step 204 Goto Step 200 .
FIG. 6 shows an example of a sequential digital profile 25 according to FIG. 2 wherein:
(i) the sequence of samples 40 contains four samples: S 1 , S 2 , S 3 , S 4 ;
(ii) the list of attributes 60 consists of the following off-segment attributes 61 {OFA 1 =Period_of_duration, OFA 2 =Type_of_monotonicity}, and the following in-segment attributes 62 {INA 1 =Period_of_duration};
(iii) the sequences of off-segment attribute values 63 are
{OFA 1 (SI)=“don't care”, OFA 2 (S 1 )=“don't care”},
{OFA 1 (S 2 )=“1.0 sec÷2.0 sec”, OFA 2 (S 2 )=“increasing”}
{OFA 1 (S 3 )=“>0.3 sec”, OFA 2 (S 3 )=“decreasing”},
{OFA 1 (S 4 )=“0.5÷2.0 sec”, OFA 2 (S 4 )=“increasing”};
(iv) the sequences of in-segment attribute values 64 are:
{INA 1 (S 1 )=“>1.0 sec”},
{INA 1 (S 2 )=“>1.0 sec”},
{INA 1 (S 3 )=“>0.5 sec”},
{INA 1 (S 4 )=“>1.0 sec”}.
FIG. 7 shows a design of a processing unit 12 which can perfom attribute measurements required for the sequential digital profile of FIG. 6 . The structure of the unit corresponds to the general structure of FIG. 3 .
The range selector 125 consists of two analog comparators 251 and 252 comparing the incoming signal 20 to the content of the range buffers 123 and 124 respectively. The AND-gate 253 provides that the binary output 254 of the range selector 125 is set ONE when the incoming signal 20 is within said range, and ZERO otherwise.
There are two modules 121 , i.e. the module to perform Period_of_duration measurements, and the module to perform Type_of_monotonicity measurements. The module performing Period of duration measurements consists of the digital counter 211 with the reset signal 141 connected to the ouput 254 . The clock input of the counter 211 is connected to the external signal generator. The module performing Type_of_monotonicity measurements consists of the differentiating element 212 , the sign detector 213 , and two flip-flops 214 and 215 . The small histeresis loop has been added in the sign detector 213 in order to compensate minor variations of the incoming signal 20 . The flip-flop 214 is set whenever the derivative of the incoming signal 20 is positive, and the flip-flop 215 is set whenever the derivative of the incoming signal 20 is negative. The reset signal 141 resets the flip-flops 214 and 215 and closes their Set input AND-gates.
There is only one module 122 to perform Period_of_duration measurements. It consists of the digital counter 222 with the reset signal 142 connected to the inverted output 254 . The clock input of the counter 222 is connected to the external signal generator.
The measurement buffer 131 is a latch register with two inputs connected to flip-flops 214 and 215 , and the rest of inputs connected to the counter 211 . The load signal 151 is connected to the inverted output 254 .
The measurement buffer 132 is a latch register with the inputs connected to the counter 222 . The load signal 152 is connected to the output 254 .
The attribute buffers 126 and 127 are not incorporated since there is only one sequential digital profile requiring measurements performed by all available modules 121 and modules 122 .
Therefore, the attribute measurements 30 (comprising off-segment attribute measurements 33 and in-segment attribute measurements 34 ) are represented as follows:
Off-segment Period_of_duration—the corresponding output bits of the buffer 131 ;
Off-segment Type_of_monotonicity—two output bits of the buffer 131 , wherein
01 represents “decreasing”;
10 represents “increasing”;
11 represents “no_monolonicity”;
In-segment Period_of_duration—the output bits of the buffer 132 .
FIGS. 8 to 11 show examples of incoming analog signals 20 being processed by the algorithm of FIG. 4 using processing unit of FIG. 7 and the sequential digital profile 25 of FIG. 6 . The extracted segments 81 , 82 , 83 and 84 correspond respectively to the samples S 1 , S 2 , S 3 and S 4 from the sequence of samples 40 . Some of the above mentioned segments may repeat within incoming signals 20 because of Step 107 of said algorithm which restarts analysis from the first sample S 1 after unsuccessful attempt to extract segments corresponding to all samples of the sequence of samples 40 . The lists 91 , 92 , 93 and 94 contain the corresponding attribute measurements 33 and 34 (the measurements which do not match the corresponding attribute values from the sequences 63 and 64 are crossed).
Therefore, the signals of FIG. 8 and FIG. 9 satisfy the requirements of the sequential digital profile 25 of FIG. 6, while the signals of FIG. 10 and FIG. 11 do not.
Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.
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A method for encryption and decryption of analog signal, wherein encryption and decryption are performed in analog domain. The transmitter creating digital representations with unique behavior; producing computation instructions for each digital representation; randomly generating analog identification signals with random waveform appearance and yet preserving common behavior as in said digital representation; encryption through partitioning said analog signal and inserting said analog identification signals prior to, in between, and/or after said partitioned analog signal segments. As a result, encrypted analog signal sequence becomes totally destructed to unauthorized receivers. An authorized receiver measuring incoming analog signal according to said digital representation or said computation instruction, locating identification signals within said incoming signal sequence through satisfying said digital representation; decryption through deleting all said identification signals and reconstructing said incoming analog signal to its original form.
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PRIORITY CLAIM
[0001] This application is a continuation of U.S. patent application Ser. No. 13/962,871 filed on Aug. 8, 2013, which is a continuation of U.S. patent application Ser. No. 12/762,900 filed on Apr. 14, 2010 (now U.S. Pat. No. 8,526,898), which claims the benefit of priority to U.S. provisional application 61/170,526 filed Apr. 17, 2009, now expired. Each of the above referenced documents is hereby incorporated by reference in its entirety.
BACKGROUND
[0002] This invention relates to wideband receiver systems and methods having a wideband receiver that is capable of receiving multiple radio frequency channels located in a broad radio frequency spectrum. In particular, the invention relates to wideband receiver systems that are capable of receiving multiple desired television channels that extend over multiple non-contiguous portions of the broad frequency spectrum and grouping them into a contiguous, or substantially-contiguous, frequency spectrum.
[0003] Receivers used to down-convert and selectively filter TV channels are referred to as tuners, and tuners designed to concurrently receive several TV channels are referred to as wideband tuners. Existing tuners for these applications down-convert a swath of channels to an intermediate frequency, which are then sent to a demodulator. Because the swath of channels is not contiguous, this swath includes the desired channels as well as undesired channels. The demodulator employs a high-speed data converter to capture this swath of desired and undesired channels in the digital domain and subsequently filters out the desired channels.
[0004] In general, television channels broadcasted over the air or over cable networks are distributed across a broad frequency spectrum. That is, the channel frequencies may not be adjacent to each other. In certain applications such as DVR and picture-in-picture, the receiver system may have to concurrently receive several desired channels that may or may not be contiguous. The wideband receiver requirement poses a trade-off to the system to limit either the dynamic range of the wideband tuner or reduce the bandwidth covered by the tuner so that fewer channels may be received and processed by the demodulator.
[0005] FIG. 1 shows a conventional wideband tuner 100 . Tuner 100 may be a direct conversion tuner and includes a low noise amplifier LNA1 having an input terminal coupled to a radio frequency (RF) input signal 102 and an output terminal coupled to a mixer M1. The RF signal may include one or more television channels receiving from a cable network via an RF connector or wirelessly via an antenna. The RF input signal may include the VHF and UHF television channels in a terrestrial television broadcasting system or the CATV channels in cable networks. In order to receive all broadcasted channels present in the RF input signal, LNA1 must necessarily have a wide tuning range, high linearity, and low noise. Mixer M1 is coupled to a synthesizer S1 that can generate an oscillator frequency located around the center of the RF signal. Mixer M1 frequency down-converts the received RF input signal to a more convenient intermediate frequency (IF) band. Tuner 100 includes an amplifier V1 having a programmable gain for amplifying the IF signal, which is then band-pass filtered by a filter F1 before outputting to a demodulator.
[0006] In general, the RF signal includes multiple desired channels that are located in non-contiguous portions of a radio frequency spectrum. As shown in FIG. 1 , the swath of channels 110 occupies a bandwidth BW1 120 at an RF center frequency f rfc 130 . Synthesizer S1 may be tuned to a frequency around the center frequency f rfc 130 for mixing channels 110 to an intermediate frequency f ifc 160 , the frequency down-mixed channels 140 are amplified by amplifier V1 and then filtered by F1 to produce a swath of channels 170 centered around frequency f ifc 160 . In an exemplary application shown in FIG. 1 , bandwidth BW1 contains 10 channels. In the case where channels are TV channels that are spaced at either 6 MHz or 8 MHz in most parts of the world, bandwidth BW1 120 would span from 60-80 MHz, i.e., the down-converted bandwidth at the intermediate frequency would require a bandwidth equal to at least BW1, or at least 80 MHz when such architecture is used. It is noted that in other applications where the desired RF channels are located in the low band such as channels numbers 2 to 6 (VHF in the terrestrial TV broadcast or CATV) and in the high band such as channels numbers 14 to 83 of the UHF TV broadcast or channel numbers 63-158 of the CATV's ultra band, the bandwidth BW1 can be 800 MHz or higher. This wide bandwidth of 800 MHz would require a very expensive digital processing circuitry such as very high-speed analog to digital conversion and high-speed processor in the demodulator.
[0007] It is desirable to have wideband receiver systems that can increase the dynamic range without requiring expensive data conversion, filtering and channel selection at the demodulator.
BRIEF SUMMARY
[0008] An embodiment of the present invention includes a wideband receiver system that is configured to concurrently receive multiple radio frequency (RF) channels including a number of desired channels that are located in non-contiguous portions of a frequency spectrum and group the desired channels in a contiguous or substantially-contiguous frequency band at an intermediate frequency spectrum, where the term “substantially-contiguous” includes spacing the desired channels close to each other (e.g. as a fraction of the total system bandwidth, or relative to a channel bandwidth) but with a spacing that can be variable to accommodate the needs of overall system. The term “contiguous” heretofore encompasses “substantially-contiguous.” The term “spacing” is referred to as the frequency difference between adjacent channels. The system includes a wideband receiver having a complex mixer module for down-shifting the multiple RF channels and transforming them to an in-phase signal and a quadrature signal in the baseband or low intermediate frequency (IF) band. The system further includes a wideband analog-to-digital converter module that digitizes the in-phase and quadrature signals. The digital in-phase and quadrature signals are provided to a digital frontend module that contains a bank of complex mixers that frequency-shift the number of desired channels to a baseband where the desired channels are individually filtered.
[0009] The digital frontend module may also include a decimator module that decimates the desired RF channels by a factor M before demodulating them to a digital data stream.
[0010] In certain embodiments of the present invention, the wideband receiver system additionally includes an up-converter module having multiple complex up-mixers, each of the complex up-mixers is configured to frequency up-shift each one of the desired RF channels to a sub-portion of an IF spectrum, wherein all sub-portions of the desired channels are adjacent to each another and form a contiguous frequency band in the IF spectrum. The act of frequency shifting the desired channels to the IF spectrum allows the wideband receiver system to directly interface with commercially available demodulators. Allowing the spacing of the desired channels in the contiguous spectrum to be variable allows a system to optimize placement of these desired channels for the purposes of avoiding sensitive portions of the spectrum which may either be vulnerable to spurious signals and interference; or which may generate interference directly or as a harmonic product, to other systems.
[0011] In another embodiment of the present invention, a multi-tuner receiver system having two or more tuners is provided to receive multiple desired RF channels that extend over several non-contiguous sub-portions of a broad frequency spectrum and group them into a contiguous frequency spectrum. The multi-tuner system includes at least a first tuner that processes a first sub-portion of the broad frequency spectrum into a first in-phase signal and a first quadrature signal and a second tuner that processes a second sub-portion of the broad frequency spectrum into a second in-phase signal and a second quadrature signal. The multi-tuner receiver system further includes a first analog-to-digital converter module that digitizes the first in-phase and quadrature signals and a second analog-to-digital converter module that digitizes the second in-phase and quadrature signals. In addition, the multi-tuner system includes a first digital frontend module having a first number of complex mixers corresponding to a first number of the desired RF channels located in the first sub-portion of the broad frequency spectrum and a second digital frontend module having a second number of complex mixers corresponding to a second number of the desired RF channels located in the second sub-portion of the broad frequency spectrum. The first digital frontend module frequency shifts the first number of the desired RF channels to a first plurality of baseband signals and the second digital frontend module frequency shifts the second number of the desired RF channels to a second plurality of baseband signals.
[0012] The multi-tuner system further includes a first up-converter module having a plurality of N complex mixers, wherein N is an integer value equal to the number of desired channel. The first up-converter module frequency up-shifts the first plurality of the baseband signals to a first portion of an intermediate frequency. In addition, the multi-tuner system includes a second up-converter module that frequency up-shifts the second plurality of the baseband signals to a second portion of an intermediate frequency. The first and the second portions of the intermediate frequency are non-overlapping and located adjacent to each other to form a contiguous intermediate frequency (IF) band. The multi-tuner system further includes a digital-to-analog converter that converts the contiguous IF band to an analog waveform signal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a schematic block diagram of a conventional wideband tuner;
[0014] FIG. 2 is a schematic block diagram of a wideband receiver system according to an embodiment of the present invention;
[0015] FIG. 3 is a simplified circuit diagram of a complex down-mixer according to an embodiment of the present invention;
[0016] FIG. 4 is a simplified schematic block diagram of a wideband receiver system according to another embodiment of the present invention;
[0017] FIG. 5 is a simplified circuit diagram of a complex up-mixer according to an embodiment of the present invention;
[0018] FIG. 6 is a simplified schematic block diagram of a wideband multi-tuner receiver system according to an embodiment of the present invention;
[0019] FIG. 7 is a block diagram illustrating an exemplary digital front end according to an embodiment of the present invention in more detail;
[0020] FIG. 8 is a block diagram illustrating an exemplary tiled up-converter module according to an embodiment of the present invention in more detail;
[0021] FIG. 9 is a simplified block diagram of a wideband multi-tuner receiver system 900 according to an embodiment of the present invention; and
[0022] FIG. 10 is a simplified block diagram of a wideband multi-tuner receiver system 1000 according to another embodiment of the present invention.
DETAILED DESCRIPTION
[0023] FIG. 2 is a schematic block diagram of a wideband receiver system 200 according to an embodiment of the present invention. Wideband receiver system 200 includes a radio front end 210 and a digital front end 230 . Radio front end 210 may be a single very wide-band tuner receiver that captures the desired swath of channels located in non-contiguous portions of the spectrum having a frequency bandwidth BW1 120 . In this example, the number of available channels in BW1 120 is assumed to be 10 with each channel occupying an 8 MHz bandwidth for a total of 80 MHz. Radio front end 210 is shown as including a low noise amplifier LNA 202 having an input terminal configured to receive an RF input signal 102 . In the example shown, RF signal 102 includes four desired RF channels having the respective carrier frequency f rf1 , f rf2 , f rf3 , and f rf4 that are located in non-contiguous portions of the wide frequency spectrum BW1. It is understood, however, that spectrum BW1 120 may have any other number of desired frequencies that are not contiguous. LNA 202 has a very low noise figure and very high linearity and a wide tuning range (i.e., very high IIP2 and IIP3 intercept points) to maximize a signal-to-noise-and distortion ratio (SNDR) at the amplifier output. LNA 202 may have a programmable gain to amplify RF signal 102 to adequate voltage levels for mixers M1 211 and M2 221 .
[0024] Mixers M1 211 and M2 221 may be conventional mixers formed using, for example, differential Gilbert cells. Each of the mixers 211 and 221 multiplies (mixes) an amplified RF signal 203 with a respective first oscillator frequency signal 205 and a second oscillator frequency signal 207 to generate an in-phase signal 212 and a quadrature signal 222 that have a phase shift of 90° degree between them. Mixers 211 and 221 are identical so that the amplitude of the in-phase signal 212 and quadrature signal 222 are the same. The first and second oscillator frequencies 205 and 207 are identical and have a 90° degree phase shift generated through a 90° degree phase shifter P1 206 . Synthesizer S1 may be a single local oscillator operable to generate the oscillator frequency 205 for converting the receive RF signal 102 to a zero-IF or low-IF band. Synthesizer S1 can be a coarse (large step) phase locked loop. Synthesizer S1 can also be programmable to cover the wideband frequency of the analog and digital terrestrial broadcast and/or the cable television system. The RF signal 102 may have relatively uniform signal strength in a cable network. However, its signal strength may extend in several orders of magnitude in a terrestrial broadcast system, thus, LNA 202 and/or mixers M1 211 , M2 221 are required to have a relatively high dynamic range to handle the large variations in the signal strength.
[0025] In-phase signal 212 and quadrature signal 222 are further amplified and filtered by respective amplifiers V1 213 , V2 223 and filters F1 215 , F2 225 to generate a filtered in-phase signal 216 and a filtered quadrature signal 226 . Filters F1 215 and F2 225 may be passive or active low-pass filters to filter out any unwanted frequency components of the signals 214 and 224 before digitizing them for further processing in digital front end 230 . It is understood that the in-phase path 216 and the quadrature path 226 must have the same amplitude spectrum and maintain a fixed phase relationship, i.e., amplifiers V1 213 , V2 223 and filters F1 215 , F2 225 must be substantially identical. Because the two paths 216 and 226 are in quadrature, the spectral components from both positive and negative frequencies can be overlaid so that the bandwidth (cutoff frequency) of filters F1 215 and F2 225 can be one half of the BW1 bandwidth 120 .
[0026] Analog-to-digital converters ADC1 218 and ADC2 228 are high-speed (i.e., high sampling rate) converters to maximize the dynamic range. In an exemplary application, radio front end 210 operates as a nominal zero-IF down-mixer so that signals 216 and 226 have a nominal bandwidth 290 equal to one half of the RF signal bandwidth BW1 thanks to the complex down-mixer architecture. In other embodiment, radio front end 210 operates as a low-IF down-mixer so that the nominal bandwidth 290 of signals 216 and 226 is greater than one half of the bandwidth BW1. In practice, the sampling rate of ADC1 218 and ADC2 228 is chosen to be higher than the Nyquist sampling requirement, i.e., the filtered analog quadrature signals 216 and 226 may be over-sampled in order to reduce or avoid aliasing of undesired signals into the digitized I and Q signals.
[0027] ADC1 218 generates a digital signal I 232 that is a digital representation of the analog filtered signal 216 ; ADC2 228 generates a digital signal Q 242 that is a digital representation of the analog filtered signal 226 . Digital signals I 232 and Q 242 are then applied to a bank of N complex mixers 250 , wherein N is an integer value corresponding to the number of desired RF channels located in the non-contiguous portions of the frequency spectrum BW1. It is understood that the number N can be any integer value. In one embodiment, N can be equal to the number of all available channels that exist in the licensed frequency spectrum to provide system flexibility. In other embodiments, N can be equal to the number of all receivable channels within a geographic area. In yet another embodiment, N can be an integer value less than the number of receivable channels with the geographic area to reduce system costs. In the exemplary embodiment shown in FIG. 2 , the number of desired channels is 4. That is, each of the 4 complex mixers 250 mixes in-phase and quadrature signals 232 and 242 with an associated frequency to generate a corresponding baseband, which is then individually filtered, decimated and provided to an associated demodulator.
[0028] Each of the N complex mixers 250 receives the digital signals I 232 and Q 242 from ADCs 218 and 228 to extract a different one of the desired channels and frequency-shifts the extracted signals to the baseband frequency. Each of the frequency shifted desired channels 252 is filtered by an associated filter module (identified as 260 a to 260 n ). In an embodiment, each of the filtered signals 260 a to 260 n may be sent directly to an associated demodulator (identified as 270 a to 270 n ) for extracting the original information transmitted in the associated desired channel. In another embodiment, each of the filtered signals 262 a to 262 n is further decimated before providing to a demodulator. A path of digital front end 230 is described in more detail below.
[0029] FIG. 3 is a simplified circuit diagram of one of the signal paths 272 a to 272 n of digital front end 230 shown in FIG. 2 according to an embodiment of the present invention. In an embodiment, digital signal I 232 may be further filtered by a filter 311 to obtain a filtered signal 312 . Similarly, digital signal Q 242 may be further filtered by a filter 321 to obtain a filtered signal 322 . Thus, digital signals 312 and 322 only contain low-frequency components with undesired high-frequency components being eliminated by respective filters 311 and 321 . It is noted that filtered signals 312 and 322 are interposed between the respective ADCs 218 , 228 and the bank of N complex mixers 250 .
[0030] Mixer 300 , which represents one of the N complex mixers 250 , includes four multipliers 313 , 315 , 323 , and 325 . Multipliers 313 and 315 multiply the filtered signal 312 with respective cos(ω ci t) and sin(ω ci t) signals and generate respective products 314 and 316 . Similarly, multipliers 323 and 325 multiply the filtered Q signal 322 with respective cos(ω ci t) and sin(ω ci t) signals and generate respective products 324 and 326 . An adder 317 sums the products 314 and 326 to generate a frequency-shifted signal I 318 . An adder 327 sums the products 324 and 316 to generate a frequency-shifted signal Q 328 . Basically, complex mixer 300 causes a frequency shift of the filtered components 312 and 322 to respective baseband signals 318 and 328 in the digital domain according to the operation:
[0000] Y ( t )= X ( t )* e −jω c t (1)
[0000] or taken the Fourier transform, we obtain:
[0000] Y (ω)= X (ω−ω c ) (2)
[0031] Multipliers 313 , 315 , 323 , and 325 are identical digital multipliers. In an embodiment, a numerically controlled oscillator with quadrature output generates the cos(ω ci t) and sin(ω ci t) signals. Numerically controlled oscillators (NCO) can be implemented using a phase accumulator and a look-up table. NCOs are known to those of skill in the art and will not be described herein. The frequency ω ci is so chosen that each one of the desired channels embedded in the digital signals I 232 and Q 242 will be downshifted to the baseband. In the given example shown in FIG. 2 , the bank of N complex mixers will have four complex mixers, each one of the N (i.e., four) complex mixers is coupled to an individual NCO having a distinct frequency ω ci so that when mixing the filtered digital I and Q signals 312 and 322 with that frequency, each one of the complex mixers will generate the signals I ( 318 ) and Q ( 328 ) of a corresponding one of the desired channels at the baseband.
[0032] In an embodiment, baseband signals 318 and 328 are further individually filtered by respective filters 330 and 340 that are identified as one of the filters 260 a - n in FIG. 2 . Filters 330 and 340 may be band-pass or low-pass filters having a narrow bandwidth equal to the bandwidth of a desired channel. In certain embodiments, filters 330 and 340 can be analog passive or active low-pass or complex band-pass filters such as polyphase filters. In another embodiment, filters 330 and 340 can be digital low-pass filters, such as finite impulse response (FIR) filters to eliminate high frequency components that may be aliased back to the baseband signals Ii ( 332 ) and Qi ( 342 ) when decimated by subsequent decimator 350 .
[0033] The reduced sampling rate of the N desired baseband channels will be sent as a serial or parallel digital data stream to a demodulator using a serial or parallel data interface according to commonly known methods, as shown in FIG. 2 . This approach provides several advantages over conventional tuner architectures. First, it eliminates the need of expensive data conversion, filtering and channel selection on the demodulator side. Second, it removes undesired channels from the signal path at an early stage, thus relieves the large dynamic range requirement in the demodulator.
[0034] FIG. 4 shows a simplified schematic block diagram of a wideband receiver system 400 according to another embodiment of the present invention. Wideband receiver system 400 includes a radio front end 410 , a digital front end 430 , a tiled up-conversion module 450 , and a summing digital-to-analog converter module DAC 470 . Radio front end 410 includes a low noise amplifier LNA1 that receives an RF input signal 102 and provides an amplified RF signal 403 to mixers M1 411 and M2 421 . Mixer M1 411 is coupled to an oscillator frequency 405 of a synthesizer S1 whereas mixer M2 421 is coupled with the oscillator frequency 405 via a phase shifter P1 406 that generates a 90° degree phase-shift to the oscillator frequency 405 . Mixers M1 411 and M2 421 generate respective in-phase signal 412 and quadrature signal 422 that are further amplified by respective amplifiers V1 413 and V2 423 . The amplified in-phase and quadrature signals 414 , 424 are then filtered by filters F1 415 and F2 425 to eliminate undesired frequency components that would be aliased back to the in-phase and quadrature signals when digitally sampled by subsequent analog-to-digital converters ADC1 418 and ADC2 428 . Digital signals I 422 and Q 442 at the input of digital front end 430 are digital representations of the filtered analog in-phase and quadrature signals 416 , 426 before the ADCs. Digital front end 430 include a bank of N complex mixers 432 comprising 432 a to 432 n identical mixers, where N is an integer value corresponding to the number of the desired channels located in non-contiguous portions of the frequency spectrum. Each of the N complex mixers 432 a to 432 n frequency down-converts signals I 432 and Q 442 to an associated baseband. Each of the frequency down-converted I and Q signals are coupled to respective low-pass, band-pass, or decimating filters 434 . In this regard, the radio front end 410 and the digital front end 430 are similar to respective radio front end 210 and digital front end 230 of FIG. 2 that have been described in detail above.
[0035] In an alternative embodiment of the present invention, the N filtered and decimated channels 438 a to 438 n (where indices a to n correspond to the associated number of desired channels) are not provided to a demodulator for demodulation. Instead, the N filtered and decimated channels 438 a to 438 n are further frequency up-converted to an intermediate frequency (IF) spectrum. In order to achieve that, the N filtered and decimated channels are coupled to a tiled up-conversion module 450 that includes a bank of N complex up-mixers, where N is an integer value correspond to the number of desired received channels. The N complex up-mixers include identical digital mixers 452 a to 452 n that will be described further in detail below with reference to FIG. 5 . The N up-shifted channels are then filtered by a subsequent bank of channel filters 454 that, in an embodiment, comprises N individual finite impulse response (FIR) filters. The N filtered channels are then digitally combined and converted to the analog domain by a summing digital-to-analog converter module DAC 470 . The N up-shifted channels are adjacent to each other and form a contiguous or substantially-contiguous set of channels 475 in the IF spectrum centered around f if as illustrated in FIG. 4 . In an embodiment, the spectra of the mixed products are spaced in such a way so as to avoid overlap with known frequency bands containing potential or actual interferers. In another embodiment, the spectra of the mixed products are spaced in such a way so as to avoid overlap with frequency bands that might introduce interference to other systems. In general, because the bandwidth BW 2 is substantially lower than BW 1 , the IF frequency f if can be set proportionally lower, e.g., typically about 16 MHz to accommodate the spectrum of BW2 of up to 32 MHz (corresponding to the total bandwidth of the four desired channels, each having a bandwidth of 8 MHz in this example).
[0036] The up-conversion approach of FIG. 4 provides several advantages over conventional tuner architectures. First, it allows the demodulator to operate the data converter at a lower data rate and with lower resolution (fewer bits) due to the fact that the contiguous channels have a narrower bandwidth. Second, the up-conversion approach provides full compatibility with existing demodulators that require an analog IF signal. Third, it removes undesired channels from the signal path at an early stage, thus relieves the requirement of a high dynamic range requirement of the demodulator's analog-to-digital converter and the demodulator itself.
[0037] FIG. 5 shows a simplified exemplary circuit diagram of a complex up-mixer 500 according to an embodiment of the present invention. Up-mixer 500 is one of the N complex up-mixers 452 a to 452 n in tiled up-conversion module 450 shown in FIG. 4 . Up-mixer 500 includes filter 510 and 520 configured to eliminate unwanted frequency components present in respective input signals I 501 and Q 502 . Filtered signals 512 and 522 are provided to up-mixers UMI 515 and UMQ 525 that multiply the filtered signals 512 and 522 with respective cos(ω u t) and sin(ω u t). The products 516 and 526 are summed in an adder 530 to generate an IF signal 532 according to the following equation:
[0000] IF( t )= I ( t )*cos(ω u t )+ Q ( t )*sin(ω u t ) (3)
[0038] Up-mixers UMI 515 and UMQ 525 are identical digital multipliers that multiply the respective filtered signal 512 and 522 with a cosine function 505 and a sine function 506 that can be generated from a NCO using a digital phase accumulator and a look-up table.
[0039] As described above, TV channels are grouped into multiple frequency bands in North America. For example, channels 2 through 6 are grouped in VHF-low band (aka band I in Europe), channels 7 through 13 in VHF-high band (band III), and channels 14 through 69 in UHF band (bands IV and V). In order to receive such a wide frequency spectrum, the low noise amplifier and mixer must have very low noise, wide tuning range and high linearity as described above in the wideband receiver systems 200 and 400 . However, a wideband receiver having a single tuner with high sensitivity may have a high power consumption. For certain applications, it may be advantageous to use multiple tuners that are optimized for a given frequency band, such as a dedicated tuner for the low VHF band, another dedicated tuner for the high VHF band and the UHF band, and yet other dedicated tuners for receiving the digital video broadcasting (DVB) via satellite (DVB-S), via cable (DVB-C), or terrestrial digital video broadcasting (DVB-T). The multi-tuner approach may also be advantageously applied to cable networks that carry TV programs on an 88 MHz to 860 MHz according to the Data Over Cable Service Interface Specification (DOCSIS) protocol.
[0040] FIG. 6 shows a simplified schematic block diagram of a wideband multi-tuner receiver system 600 according to an embodiment of the present invention. In an embodiment, multi-tuner system 600 includes low noise amplifier A1 602 for receiving an RF input signal 601 . Amplifier A1 602 is coupled to at least a tuner1 610 and a tuner2 720 . In another embodiment, multi-tuner system 600 may not include amplifier 602 so that RF input signal 601 can be received directly at each tuner 610 and 720 .
[0041] Tuner1 610 includes an amplifying filter AF1 613 that filters and amplifies a first portion BWtuner1 604 of a broad frequency spectrum 608 that contains a first plurality of RF channels 606 including desired channels 607 having respective channel frequencies f rf1 and f rf2 . The first portion of the broad frequency spectrum BWtuner1 604 is then frequency down-converted to a low-IF or zero-IF in-phase signal I1 612 and a quadrature signal Q1 622 through respective mixer M1 611 and M2 621 . Signals I1 612 and Q1 622 are further amplified and low-pass filtered before applying to respective analog-to-digital converters ADC1 618 and ADC2 628 that convert analog signals Ia1 616 and Qa1 626 to respective digital in-phase signal Id1 631 and digital quadrature signal Qd1 641 . Because tuner1 610 only covers a portion BWtuner1 604 of the entire frequency spectrum 608 having fewer channels, the ADC1 618 and ADC2 628 can be slower-speed analog-to-digital converters with a large number of bits, i.e., large dynamic range.
[0042] Digital signals Id1 631 and Qd1 641 are then provided to a digital front end DFE 630 that includes a first bank of N complex mixers 632 and channel and decimating filters 634 . The first bank of N complex filters 632 has N identical complex mixers, where N is an integer value equal to the number of desired channels located in the first portion BWtuner1 604 of the broad frequency spectrum 608 . In an embodiment, each one of the first bank of N complex mixers includes four digital mixers that multiply digital stream Id1 631 and Qd1 641 with respective digitized cosine function and sine function to generate the sum and difference frequency components, as shown in FIG. 3 . The digitized cosine and sine frequency, i.e., the mixer frequency is so chosen so that when mixing signals Id1 631 and Qd1 641 will move them to a baseband or a low-IF band. In an embodiment, channel and decimating filters have similar structures as filters 330 and 340 and demodulator 350 as shown in FIG. 3 . That is, channel and decimating filters include digital low-pass filters 330 and 340 that eliminates unwanted high frequency components of the baseband signals I and Q prior to applying them to a decimator 350 ( FIG. 3 ) that reduces the sample frequency without any loss of information since Id1 631 and Qd1 641 are sampled at a much higher frequency by the respective ADC1 618 and ADC2 628 .
[0043] The decimated desired channels are then provided to an up-converter module 650 that includes a bank of N up-mixers. The bank of N up-mixers includes N identical up-mixers whose structure is shown in FIG. 5 . In an embodiment, N is an integer value equal to the number of desired channels present in BWtuner1 604 . Each one of the up-mixer frequency-shifts the baseband signals I and Q of each one of the desired channels to an appropriate portion of the intermediate frequency band according to Equation (3). In other words, the bank of N up-mixers is “frequency multiplexing” the desired channels onto a first portion 682 of an IF band 686 .
[0044] Similarly, tuner2 720 includes an amplifying filter AF2 713 that is configured to receive a second portion BWtuner2 704 of the broad frequency spectrum 608 . The second portion 704 contains a second plurality of RF channels 706 including a second number of desired channels. In the exemplary illustration of FIG. 6 , the second portion 704 has a frequency bandwidth of BWtuner2 that contains desired channels 707 having respective channel frequencies f rf3 and f rf4 . Tuner2 720 includes elements such as mixers M3 711 , M4 721 , amplifiers V3 714 , V4 724 , filters F3 715 , F4 725 and analog-to-digital converters ADC3 731 and ADC4 741 that are substantially the same as the like-named elements of the signal path of tuner1 610 . Thus, redundant description is omitted herein.
[0045] Digital in-phase signal Id2 731 and digital quadrature signal Qd2 741 are then provided to digital front end 740 . Digital front end 740 includes a bank of L complex filters, where L is an integer value equal to the number of desired channels in the second portion BWtuner2 704 of the broad frequency spectrum 608 . Each one of the bank of L complex filters is a digital complex mixer configured to transform the signals Id2 731 and Qd2 741 to baseband signals that are further filtered by individual digital low-pass filters such as FIR filters before decimated by a subsequent decimator. The elements of digital front end 740 are substantially similar to those described in digital front end 630 . Thus, redundant description is omitted herein.
[0046] The decimated baseband I and Q channels are further provided to a subsequent up-conversion module 760 that performs a function substantially similar to that of the up-conversion module 650 already described above. The outputs of up-conversion module 650 and 760 can be tiled to generate a contiguous set of IF frequencies 682 , 684 centered at f if 686 . In an embodiment, the outputs of up-conversion module 650 and 760 are digitally summed and converted to an analog signal by summing DAC 670 . In another embodiment, the up-conversion modules 650 and 760 and the digital summing function 672 can be performed using an inverse discrete Fourier transform or an inverse Fast Fourier transform operation.
[0047] The multi-tuner architecture provides the flexibility that multiple commercially available tuners can be used without the need of designing a wideband tuner. For example, a tuner designed for a terrestrial broadcast digital TV can be used together with a tuner dedicated to receiving a cable signal and/or a tuner for receiving a satellite broadcast signal. The multi-tuner receiver system provides an additional advantage that other tuners can be added quickly to the system to accommodate any future applications. Additionally, the multi-tuner architecture allows the use of slower speed (i.e., lower cost) analog-to-digital converters with a larger number of bits for achieving large dynamic range.
[0048] FIG. 7 shows a block diagram of an exemplary digital front end of the invention in more detail. In an embodiment, in-phase signal Id2 731 and quadrature signal Qd2 741 at the output of respective ADC converters 718 and 728 are provided to each of the L complex mixers 732 comprising mixers 732 A to 732 L. A more detailed description of each of L complex mixers is shown in FIG. 3 . Mixer 732 A multiplies Id2 731 and Qd2 741 with a cosine signal and a sine signal that are generated from an NCO1 and produces an I- 732 A signal and a Q- 732 A signal that are further individually filtered by an FIR filter before decimating. The bank of L complex mixers corresponds to the block 732 in FIG. 6 ; and the set of FIR filters and decimator corresponds to the block 734 in FIG. 6 . Each decimated pair of I- 732 i /M in the baseband, where the index “i” is from A to L, is further provided to a subsequent up-mixer for frequency-shifting to an intermediate frequency as shown in FIG. 8 .
[0049] FIG. 8 shows an exemplary embodiment of a bank of L complex up-mixers according to the present invention. Each decimated pair of complex signals I- 732 i /M and Q- 732 i /M is provided to an associated complex up-mixer, whose frequency is so chosen that when mixing with the pair of complex signals I- 732 i /M and Q- 732 i /M will generate an associated channel at a predetermined sub-portion of the intermediate frequency band 686 ( FIG. 6 ). A more detailed schematic block of one of the L up-mixers is described above together with FIG. 5 .
[0050] FIG. 9 is a simplified block diagram of a wideband multi-tuner receiver system 900 according to an embodiment of the present invention. In an embodiment, system 900 includes a crossbar switch 910 having at least an input terminal 912 configured to receive signals from an analog-to-digital converter (ADC) 912 and an input terminal 922 configured to receive signals from an ADC 922 . Crossbar switch 910 also includes an output terminal 924 that is coupled to a digital front end 930 . In an embodiment, input terminals 912 and 922 of crossbar switch 910 have P inputs, where P is an integer value that is equal to the total number of desired channels received by tuner1 610 and tuner2 720 . Output terminal 924 of crossbar switch 910 have Q outputs, where Q is an integer value that is equal to the total number of desired channels received by tuned 610 and tuner2 720 .
[0051] In an embodiment, digital front end 930 may include a bank of R complex mixers that frequency shifts the received channels to a baseband. Digital front end 930 may combine digital front end 630 and 740 shown in FIG. 6 . Similarly, a tiled up-conversion module 950 may include up-converter modules 650 and 760 of FIG. 6 .
[0052] System 900 further includes a summing DAC that operates similarly as summing DAC 470 and 670 that have been described in detail in relation with respective FIG. 4 and FIG. 6 above. Thus, redundant description is omitted herein.
[0053] FIG. 10 is a simplified block diagram of a wideband multi-tuner receiver system 1000 according to another embodiment of the present invention. System 1000 includes at least tuner1 610 coupled with digital front end 630 through an analog-to-digital converter 620 and tuner2 720 coupled with digital front end 740 through an analog-to-digital converter 730 . System 1000 further includes a crossbar switch 1010 that is interposed between digital front ends 630 , 740 and up-conversion modules 650 , 760 . Crossbar switch 1010 includes an input terminal 1012 having S inputs coupled with DFE 630 and an input terminal 1022 having T inputs coupled with DFE 740 . In an embodiment, S is an integer value equal to the number of desired channels processed in DFE 630 and T is an integer value equal to the number of desired channels processed in DFE 740 . Crossbar switch 1010 further includes an output terminal 1024 having U outputs coupled with up-converter module 650 and an output terminal 1024 having V outputs coupled with up-converter module 760 . In an embodiment, the total number of the outputs U and V is equal to the sum of the inputs S and T. Thus, crossbar switch 1010 allows the routing of any channel from either DFE 630 or DFE 740 to up-converters 650 or 760 . It is understood that system 1000 is not as flexible as system 900 because DFE 630 and DFE 740 are already pre-assigned to respective tuner1 ( 610 ) and tuner2 ( 720 ). However, this pre-assigned arrangement allows a simpler implementation of crossbar switch 1010 that operates at lower speeds.
[0054] While several embodiments in accordance with the present invention have been described, it is to be understood that the above description is intended to be illustrative and not restrictive. Many embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents.
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A wideband receiver system comprises a mixer module, a wideband analog-to-digital converter (ADC) module, and digital circuitry. The mixer module is configured to downconvert a plurality of frequencies that comprises a plurality of desired television channels and a plurality of undesired television channels. The wideband ADC module is configured to digitize the swatch of frequencies comprising the plurality of desired television channels and the plurality of undesired television channels. The digital circuitry is configured to select the desired plurality of television channels from the digitized plurality of frequencies, and output the selected plurality of television channels to a demodulator as a digital datastream.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a non-provisional of U.S. Provisional Patent Application Ser. No. 61/305,585, “HIDDEN FASTENER FOR DECK PLANKS WITH UNDERCUT SIDE GROOVES”, filed Feb. 18, 2010, and hereby incorporates herein by reference the disclosures thereof. The present application also hereby incorporates herein by reference all relevant disclosures of co-pending and commonly owned U.S. patent application Ser. Nos. 11/717,395, “FASTENER FOR GROOVED OR SLOTTED DECKING MEMBERS”, filed Mar. 13, 2007, and 12/573,540, “APPARATUS AND METHOD FOR RAPID INSTALLATION OF HIDDEN DECK PLANK FASTENERS”, filed Oct. 5, 2009.
FIELD OF THE INVENTION
[0002] The invention relates to deck plank fasteners for securing a deck plank to a joist and for supporting deck planks relative to one another. More particularly, the invention relates to a hidden deck plank fastener that is not visible and does not protrude from the deck surface when installed to secure a deck plank with undercut side grooves.
BACKGROUND OF THE INVENTION
[0003] One simple deck plank fastening system consists of a plurality of securing or anchoring members, such as nails or screws, driven downward through the top of a plank, such as a wood or composite board, and into the top surface of a supporting beam, such as a joist or ledger board. Although the concept is simple, professional quality installation using this approach requires a high degree of precision, significant time expenditure, and sometimes leads to a flawed result.
[0004] Deck planks installed using the simple system of the preceding paragraph must be carefully aligned to achieve a desirable aesthetic as well as functional result, for example, secure attachment and uniform spacing or parallelism without large gaps. Also, the insertion of the nails or screws must be performed carefully to ensure proper penetration of the joist, which will be concealed from view by the overlying wood board at the time of insertion, in order to achieve optimal attachment. Thus, although the system itself is simple, methods for making and using the system are not.
[0005] Even if the above-described simple system is properly installed, penetration of each deck plank by several securing members leaves each plank with a pock-marked appearance and prone to rot and weather damage, which severely decreases the longevity of the deck. In addition, each nail or screw may work loose and protrude from the upper surface of the planks, presenting a risk of injury to users of the deck. In summary, the simple conventional system of deck plank installation, using fasteners driven through each plank, detracts from the integrity of each plank and of the deck as a whole, and presents a risk of injury to users.
[0006] These and other problems have spurred on numerous advancements in the field. For instance, an improved deck plank fastening system includes fasteners that attach to a side surface of the plank and a top surface of the joist using nails or screws. Such designs facilitate uniform spacing or parallelism of planks by providing tabs or vertically oriented flanges that engage adjacent planks. The tabs facilitate installation by locating the points of penetration at more readily visible and accessible positions. The fasteners improve the longevity of the resulting deck by repositioning the point of penetration to the side of the plank, which is less prone to weathering. In addition, the tabs reduce the risk of injury to the user of the deck by hiding the nails or screws below the surface. Also, the hidden fasteners improve the aesthetic appeal of the deck.
[0007] Many other improvements and permutations have been conceived in this field, including the provision of deck planks with side grooves for receiving the teeth or tabs of hidden fasteners. Such improvements have specific advantages in specific circumstances, but have not foreclosed innovation in the field. For example, it has been proposed to provide deck planks with undercut side grooves so as to mitigate a possible problem of moisture collection in the side grooves. However, it is considered that known hidden fasteners are not compatible to planks with undercut side grooves.
SUMMARY OF THE INVENTION
[0008] According to some embodiments of the invention, a fastener is provided for hidden attachment of a deck plank to a joist. The inventive fastener includes a generally flat body that extends from a left end to a right end between leading and trailing edges. An attachment hole is formed through the body of the fastener. From the leading edge of the body, an arm extends upward. The arm includes a wing that extends away from the body. The arm also includes at least one alignment hole formed at a position substantially in registry with the position of the attachment hole along the body. A trailing leg extends upward from the trailing edge of the body. The leg includes at least one foot that extends away from the body, and also includes a notch indented toward the body substantially in registry with the position of the attachment hole along the body.
[0009] According to some embodiments of the invention, a weather shedding deck structure includes a joist, a deck plank, a fastener, and an elongated securing member. The joist has an upper edge surface to which the deck plank is attached. The deck plank has a top face and a bottom face extending between first and second ends. The top and bottom face of the deck plank are joined by first and second grooved sides. Each grooved side of the deck plank includes upper and lower nubs that are separated by a side groove. The upper nubs of the deck plank define a width of the top face and the lower nubs define a width of the bottom face that is less than the width of the top face. The deck plank is installed on the joist with its bottom face on the upper edge face of the joist. The fastener has a generally flat body that extends from a left end to a right end between leading and trailing edges, and that has an attachment hole formed through the body. The flat body of the fastener rests on the upper edge face of the joist. From the leading edge of the fastener body, a leading arm extends upward to a leading wing that extends away from the body. The leading wing is engaged into a side groove of the deck plank. The fastener also includes a trailing leg that extends upward from the trailing edge of the body to a trailing foot, which extends away from the body opposite the leading wing. The trailing leg includes a notch indented toward the body substantially in registry with the position of the attachment hole along the body. The elongated securing member is driven through the attachment hole of the fastener and into the joist.
[0010] In some aspects of the invention, a weather shedding deck may be rapidly made by repeatedly using a power driver tool to position a fastener in engagement with a groove formed in a plank positioned on a joist, while also using the power driver tool to drive an elongated securing member through the fastener and into the joist.
[0011] Thus, among other benefits, the invention provides an improved hidden deck plank fastener, which, among other desirable attributes, significantly reduces or overcomes the above-mentioned deficiencies of prior deck plank fasteners.
[0012] These and other objects, features and advantages of the present invention will become apparent in light of the detailed description of the best mode embodiment thereof, as illustrated in the accompanying drawings.
[0013] As used herein, “generally”, “substantially”, and “about” are meant to include structures or conditions that approximate an ideal desired structure or condition within reasonably achievable manufacturing and assembly tolerances, suitable for achieving the functional purpose of a component or assembly. By way of an example, a “generally” flat surface may nonetheless include small, microscopic, or perceptible roughnesses, prominences, or indentations, as well as intentional protrusions or declivities, so long as those non-flat features do not interfere with the intended purpose of the generally flat surface. Similarly, as another example, an assembly of components in “substantial” alignment to a common axis of rotation may deviate from perfectly co-axial alignment so long as all the components can rotate as intended for accomplishing the functional purpose of the assembly. The term “appreciable” is meant to indicate features or qualities that can be measured or observed by those of ordinary skill in practice of the invention, while “significant” is meant to indicate a variation of a feature or quality that measurably affects performance of a related function.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows a sectioned end view of an exemplary deck plank with an undercut side groove.
[0015] FIG. 2 shows a perspective view of a hidden fastener for use with deck planks such as the plank shown in FIG. 1 , according to an embodiment of the present invention.
[0016] FIG. 3 shows another perspective view of the hidden fastener shown in FIG. 2 .
[0017] FIG. 4 shows an end view of the hidden fastener shown in FIGS. 2-3 .
[0018] FIGS. 5 and 6 show details of FIG. 4 .
[0019] FIG. 7 shows a side view of the hidden fastener shown in FIGS. 2-6 .
[0020] FIG. 8 shows a perspective view of deck planks assembled to joists using a plurality of hidden fasteners, according to an embodiment of the present invention.
[0021] FIG. 9 shows a perspective view of another hidden fastener for use with deck planks such as the plank shown in FIG. 1 , according to another embodiment of the present invention.
[0022] FIG. 10 shows the same hidden fastener, sectioned at view line 10 - 10 shown in FIG. 9 .
[0023] FIG. 11 shows a detail of FIG. 10 .
DESCRIPTION OF PREFERRED EMBODIMENTS
[0024] FIG. 1 shows a grooved deck plank 10 that has a convex top face 12 , a bottom face 14 , a vertical mid-plane 16 , and two grooved sides 18 a , 18 b defining a profile 20 that is symmetric across the vertical mid-plane. Each grooved side has an upper nub 22 , a lower nub 24 , and a side groove 26 indented into the grooved side toward the mid-plane between the upper nub and the lower nub. The upper nub of each grooved side protrudes to a first distance from the vertical mid-plane, defining a half-width of the deck plank top face. The lower nub of each grooved side protrudes to a second distance from the vertical mid-plane, less than the first distance, defining a half-width of the deck plank bottom face. Thus, the deck plank bottom face is narrower than the deck plank top face. It is believed that the resulting profile reduces accumulation of moisture in the side grooves 26 . Although the horizontal offset of the lower nub from the upper nub may vary according to commercial specifications, a vertical angle measured across the upper and lower nubs typically may be between about five (5) and about twenty five (25) degrees.
[0025] According to an embodiment of the present invention, FIGS. 2 and 3 show a hidden deck plank fastener 30 , which has a generally flat horizontal body 32 with leading and trailing edges 34 , 36 extending from a left end to a right end. At the leading edge of the horizontal body, the hidden fastener is bent to form an upwardly extending leading arm 38 . At the trailing edge of the horizontal body, the hidden fastener is bent to form an upwardly extending trailing leg 40 . The leading arm and the trailing leg are spaced apart in parallel fashion by the horizontal body of the fastener.
[0026] The leading arm 38 is bent, at an upper bend 42 extending parallel to the body of the fastener, to form a leading wing 46 extending substantially parallel to and away from the horizontal body. The trailing leg 40 is bent at an upper bend 44 to form at least one trailing foot 48 extending substantially parallel to and away from the body. The leading wing and the trailing foot, in the embodiment shown in FIGS. 2 and 3 , are substantially coplanar.
[0027] The hidden fastener 30 also includes an attachment hole 50 formed through the horizontal body for receiving an elongated securing member for securing the hidden fastener to a joist, as further discussed below with reference to FIG. 8 . The leading upper bend 42 has alignment holes 52 a , 52 b formed therethrough, bracketing the position of the attachment hole, for engagement of the hidden fastener onto a pneumatic nail driver or other power driver tool. Additionally, the trailing leg and feet include a notch 54 , formed in registry with the position of the attachment hole, which separates the trailing foot 48 into left and right portions 48 a , 48 b . In some embodiments, the notch 54 permits access to the attachment hole by a power driver tool. In select embodiments, the alignment holes and the notch are disposed so as to engage the hidden fastener onto a power driver tool such that a securing member driven by the power driver tool will pass through the attachment hole at an angle of between about thirty (50) and about fifty (50) degrees from the plane of the leading arm 38 .
[0028] Referring to FIGS. 4 through 7 , the leading wing 44 is indented across its width by a first bend score 56 , and the trailing foot 48 is indented with a second bend score 58 . From the first bend score 56 , left and right corners of the leading wing are bent downward to form claws 60 a , 60 b for engagement with the lower nub 24 of the deck plank shown in FIG. 1 . The claws 60 a , 60 b preferably are bent downward to angles of about one hundred thirty five (135) degrees from a lower surface 64 of the leading wing 46 . From the second bend score 58 , left and right portions of the trailing foot 48 are bent downward to form toes 62 a , 62 b for engagement with the lower nub of a second deck plank similar to the deck plank shown in FIG. 1 . The toes 62 a , 62 b preferably are bent downward to angles of about one hundred fifty (150) degrees from a lower surface 66 of the trailing foot 48 . These bend angles are believed to be optimal for securely engaging deck planks with undercut side grooves, such as the plank 10 shown in FIG. 1 , without damaging lower nubs 24 of the deck planks. However, a range of suitable angles for the toes and claws may be determined based on properties of particular deck planks with which the hidden fastener 30 will be utilized. For example, surface hardness and grain strength of the deck planks may be key properties for determining suitable angles.
[0029] Referring to FIG. 8 , a plurality of hidden fasteners 30 can be used with a corresponding plurality of elongated securing members 80 for fastening a sequence of planks 10 , as shown in FIG. 1 , onto the upper edges faces 70 of a planar array of joists, which may be fixed by conventional brackets, toe-nails, or other means to a backstop 72 (such as a wall or a plane defined by an array of posts). In use, a lead plank 10 a is positioned onto the upper edge faces of the joists with one of its grooved sides 18 a positioned against the backstop and with the other grooved side 18 b “open” toward the free ends of the joists. A first group of hidden fasteners then are assembled to the lead plank with their leading wings 46 inserted into the open side groove 26 b , and each hidden fastener is attached to one of the joists 70 by an elongated securing member 80 , one fastener per joist. In some embodiments, the attachment hole 50 is dimensioned such that each elongated securing member forms a substantially water tight joint with each fastener body 32 , thereby providing for water to be shed from the upper edge face of each joist even at the locations where the elongated securing members penetrate the joists. In select embodiments, weather shedding qualities and durability of the hidden fastener and of the elongated securing member may be enhanced by selecting, for fabrication of the hidden fastener and of the elongated securing member, materials that are chemically and galvanically compatible. For example, the hidden fastener may be formed from mild steel, while in select embodiments the elongated securing member may also be formed from mild steel, or from another metal that is compatible with the hidden fastener (without appreciable mutual galvanic corrosion when in contact in an outdoor environment). In further embodiments, the materials of the hidden fastener and of the elongated securing member also may be selected for compatibility with the deck planks.
[0030] In some aspects of the invention, each of the hidden fasteners 30 in turn is held by a pneumatic nail driver or other power driver tool (not shown), is engaged with the lead plank 10 a , and concurrently is attached to one of the joist edge faces 70 by an elongated securing member driven from the power driver tool, substantially as disclosed in co-pending U.S. patent application Ser. No. 12/573,540. In some embodiments, engagement of the hidden fastener into the side groove 26 b and over the offset lower nub 24 b , may be enhanced by driving each elongated securing member 80 into the joist from the power driver tool at an angle 81 of between about twenty five (25) and about fifty (50) degrees measured in a vertical plane aligned with the joist. In some embodiments, each elongated securing member is driven at an angle of between about thirty (30) and about forty five (45) degrees.
[0031] Subsequent to attachment of the lead plank 10 a onto the joist upper edge faces 70 , a first trail plank 10 b then is assembled onto the trailing foot portions 48 a , 48 b of the first group of hidden fasteners. The trailing foot toes 62 a , 62 b flex so that trail planks may be assembled and removed to and from the hidden fasteners, without appreciable dislodgement of the hidden fasteners or significant damage to the trail plank lower nubs. A second group of hidden fasteners then are assembled to the first trail plank and attached to the several joists, substantially as for the first group of hidden fasteners. The leading arm and the trailing leg positively position the lower nubs of such planks so that the upper nubs and top faces of the planks are separated by appropriate drainage gaps. At the free ends of the joists, a cap rail 74 can be provided to cover the trailing feet of a final group of hidden fasteners.
[0032] According to another embodiment of the invention, as shown in FIGS. 9-11 , a hidden fastener 90 includes a body 92 , extending from left to right ends between a leading edge 94 and a trailing edge 96 . From the leading edge 94 , the body is bent upward to define a leading arm 98 . At an upper bend the leading arm continues to a leading wing 100 . Referring specifically to FIG. 10 , a distal portion of the leading wing is bent to define an angle 101 with reference to the leading arm 98 . In some embodiments, the angle 101 may be between about seventy (70) to about ninety five (95) degrees. In select embodiments, the angle 101 may be between about seventy five (75) to about eighty five (85) degrees. In a specific embodiment, the angle 101 is about seventy eight (77.6) degrees. The angle of the leading wing should be selected according to material of the hidden fastener 90 and according to dimensions and properties of the planks with which the hidden fastener is to be used. For example, a harder plank may require a shallower angle for proper installation of the hidden fastener.
[0033] Referring back to FIG. 9 , the bent portion of the leading wing 100 includes two alignment holes 102 a , 102 b . Corners of the leading wing also include downwardly-bent claws 104 , as further discussed below with reference to FIG. 11 . Still referring to FIG. 9 , at a location along the fastener body 92 , substantially in registry between the alignment holes, an attachment hole 114 is formed through the fastener body. In some embodiments, the attachment hole may be formed at an angle from the leading arm 98 . In other embodiments, the attachment hole may be formed generally perpendicularly through the fastener body.
[0034] Across from the leading arm 98 , the fastener body 92 is bent upward at its trailing edge 96 to form a trailing leg 106 . The trailing leg 106 is split, substantially in line with the attachment hole 114 formed through the fastener body, to form two trailing feet 108 a , 108 b and a trailing tab 110 . The trailing feet can be engaged into a side groove of a trailing deck plank to be assembled onto the hidden fastener 90 , while the trailing tab may stabilize the hidden fastener against rocking motion during installation on an upper edge surface of a joist. Additionally, the trailing tab 110 provides additional surface area for engagement with the fastener body 92 of an elongated surface member driven at an angle through the attachment hole 114 .
[0035] As shown in FIG. 10 , the trailing feet are curved rearward and downward to define angles 109 with reference to the trailing leg. In some embodiments, the angle 109 may be between about seventy five (75) to about eighty five (85) degrees. In a specific embodiment, each angle 109 is about eighty (80.0) degrees. As for the angle 101 defined by the leading wing 100 , the angle 109 should be selected according to dimensions and material properties of the hidden fastener 90 and of the range of planks with which the fastener is to be used. Generally, the angles 101 and 109 permit the hidden fastener 90 to securely engage lower nubs of a variety of side grooved deck planks, which may have either undercut or level-edged profiles with grooves located at varying heights.
[0036] Referring to both FIGS. 9 and 10 , the trailing tab 110 is deformed downward from the fastener body 92 by an upwardly concave dent or tool strike 112 , disposed generally in line with the attachment hole 114 . Opposite the trailing tab and directly across the attachment hole from the dent, the fastener body 92 is itself deformed upward by an upwardly convex divot or second tool strike 116 . The dent and the divot are disposed such that a plane tangent to both would be angled with reference to the fastener body. For example, such a plane might be angled by between about twenty five (25) to about fifty (50) degrees from the body of the hidden fastener 90 .
[0037] In use of the hidden fastener 90 , the dent may enhance engagement of the hidden fastener 90 with an upper edge surface of a joist on which the fastener is installed. Additionally, the dent and the divot may aid in properly positioning the hidden fastener 90 onto a power driver tool, such that the power drive tool may drive an elongated securing member through the attachment hole 114 and into a joist at an angle of between about twenty five (25) to about fifty (50) degrees while the leading wing 100 is engaged into a side groove of a deck plank. Moreover, the divot may enhance rigidity of the fastener body 92 for receiving, substantially without distortion, an impact from an elongated securing member driven through the attachment hole.
[0038] Referring also to FIG. 11 , the dent 112 and the divot 116 may enhance engagement of the claws 104 against a lower nub of a deck plank with which the leading wing 100 is engaged. More particularly, the dent may act as a fulcrum, such that driving a securing member through the attachment hole 114 , with the head of the securing member striking the divot, may exert substantial downward leverage on the claws 104 . In some embodiments, the claws 104 define an angle 105 with reference to the leading wing. In select embodiments, the angle defined by the claws may be between about one hundred thirty (130) and one hundred forty (140) degrees. In a specific embodiment, the angle 105 is about one hundred thirty five (135) degrees.
[0039] Although it is contemplated that the embodiments specifically shown and disclosed herein may be formed from sheet metal, one of ordinary skill will appreciate that other materials and modes of manufacture equally may be utilized for producing substantially similar embodiments. By way of example, and without intent to limit the scope of the appended claims, casting, metal injection molding, sintering, polymer injection molding, forging, or milling of metal or of high-strength polymer, all might be acceptable substitutes for sheet metal forming, presuming that appropriate modifications to dimensions could feasibly be made. Further, although only exemplary embodiments have been shown and disclosed, it will be understood that appreciable or significant changes may be made to specific shapes or dimensions without thereby substantially departing from the overall concept and functional effects of the invention.
[0040] Thus, although this invention has been shown and described with respect to the detailed embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail thereof may be made without departing from the spirit and the scope of the invention as defined by the claims appended hereto.
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Deck planks with undercut side grooves can be attached to underlying joists by hidden fasteners with leading wings and trailing feet engaged into the side grooves of the deck planks. The bodies of the hidden fasteners space the deck planks so as to provide adequate drainage gaps between the top faces of the deck planks. A power driver tool can be used for rapidly positioning the hidden fasteners and for attaching the hidden fasteners to the joists.
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CROSS-REFERENCE TO RELATED APPLICATION(S)
This application is a Continuation of U.S. patent application Ser. No. 11/470,802, filed Sep. 7, 2006, entitled “CONNECTION ARCHITECTURE FOR A MOBILE NETWORK,” which is a Continuation of U.S. application Ser. No. 10/339,368, filed Jan. 8, 2003, entitled CONNECTION ARCHITECTURE FOR A MOBILE NETWORK, now U.S. Pat. No. 7,139,565, which claims the benefit of both U.S. Provisional Application No. 60/346,881 filed Jan. 8, 2002 and U.S. Provisional Application No. 60/403,249 filed Aug. 12, 2002, all of which are herein incorporated by reference in their entirety.
BACKGROUND
Mobile email messaging systems typically use a store and forward architecture. Electronic Mail (email) redirector software runs either on an enterprise email server or on a desktop computer. The redirector software monitors a user mailbox. When a new email message is received in the mailbox, the redirector makes a copy of the email message and wraps the copy in an encryption envelope and encapsulates the copy for delivery to the mobile device. The redirector may optionally encrypt and/or digitally sign the encapsulated email message.
The encrypted encapsulated email message is sent out over the Internet and routed to a mobile device associated with the user mailbox. If encrypted, the email message is decrypted by the mobile device prior to being stored on the mobile device and then displayed and stored on the mobile device. This same process is repeated for every new email that is received in the user's mailbox.
Thus, with this architecture two versions of the same mailbox exist. The primary mailbox on the email server or desktop PC, and the replicated mailbox on the mobile device. Consistency between the primary and the replicated mailbox may be maintained to some degree using synchronization messages passing back and forth between the redirector and the mobile device. For example, an email message deleted from the mobile device may result in a synchronization message to the desktop redirector, which instructs it to also delete that message from the primary mailbox. In some versions of this architecture, no effort at all is made to ensure consistency of mailbox state between the primary and replicated instances. This store and forward architecture is cumbersome, does not operate in real-time, and requires sending a large number of email messages over the Internet. The present invention addresses this and other problems associated with the prior art.
SUMMARY
A real-time communication architecture establishes a continuous connection between an enterprise network and a communication management system. The connection is continuously held open allowing mobile devices real-time access to enterprise data sources such as email systems. The real-time communication architecture can support an entire enterprise email system or individual email users.
The foregoing and other objects, features and advantages of the invention will become more readily apparent from the following detailed description of a preferred embodiment of the invention which proceeds with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a mobile communication architecture according to one embodiment of the invention.
FIG. 2 is a block diagram of an enterprise version of the communication architecture.
FIG. 3 is a block diagram showing how transactions are transferred in the communication architectures shown in FIGS. 1 and 2 .
FIG. 4 is a block diagram showing how local network files are viewed and selected by a mobile device.
FIG. 5 is a block diagram showing how data is stored in a mobile device.
FIG. 6 is a block diagram showing how the mobile device is synchronized.
DETAILED DESCRIPTION
For simplicity, data, databases, files, and data transactions may be referred to generally as Electronic mail (email), email transactions, mailboxes, etc. However, it should be understood that any type of email data or email transaction described below can be similarly performed for calendars, contacts, tasks, notes, electronic documents, files or any other type of data that needs to be transferred between a local network and a mobile device,
FIG. 1 shows one embodiment of a real-time communication architecture 12 that includes a mobile network 14 , an enterprise network 18 , and a communication management system 16 that manages communications between the mobile network 14 and the enterprise network 18 .
The enterprise network 18 in one instance is a private network that contains a firewall 31 . The firewall 31 can be a set of related programs, located at a network gateway server that protects the resources of the enterprise network 18 from users from other networks. The term ‘firewall’ also implies the security policy that is used with the firewall programs.
The mobile network 14 includes mobile devices 21 that communicate over the Internet through a wireless or landline mobile network 14 . Since mobile networks 14 are well known, they are not described in further detail.
The enterprise network 18 can be any business network, individual user network, or local computer system that maintains local email or other personal data for one or more users. In the embodiment shown in FIG. 1 , the enterprise network 18 includes an email server 34 that is accessed by multiple Personal Computers (PCs) 38 . In one example, the email server 34 may be a Microsoft® Exchange® server and the PCs 38 may access email on the email server 34 through a Microsoft® Outlook® software application. The email server 34 can store email mailboxes, contact lists, calendars, tasks, notes, or any other type of local data or electronic document.
The PC 38 is connected to the email server 34 over a Local Area Network (LAN) 35 . The PC 38 includes memory 39 for storing local files that may include personal email data as well as any other types of electronic documents. Personal client software 40 is executed by a processor in the PC 38 . The personal client 40 exchanges transactions with the mobile device 21 for browsing email, calendars, and contact information as well as accessing local files.
A communication management system 16 includes at least one management server 28 that manages the transactions between the mobile device 21 and the enterprise network 18 . A user database 42 includes configuration information for different users. For example, the user database 42 may include login data for user's in enterprise network 18 .
Enterprise Version
FIG. 2 shows an enterprise version of the communication architecture 12 . The enterprise network 18 includes an enterprise server 34 that connects through LAN connection 35 to multiple PCs 38 . The enterprise server 34 also includes an enterprise client 41 that can communicate directly with the management server 28 .
The communication management system 16 in FIG. 2 includes the management server 28 , as well as one or more Smart Device Servers (SDS) 30 , and one or more Personal Client Servers (PCS) 32 . The SDS 30 handles communications with particular smart mobile devices 24 . The PCS 32 manages communications with personal clients 40 .
The mobile devices 21 in FIG. 2 are shown in more specificity and include cell phones 20 having WAP interfaces that communicate with management server 28 through a WAP gateway 26 . Other mobile devices 21 may include PCs, PDAs, Internet kiosks 22 , or any other smart mobile device 24 that operates as communication endpoints.
Mobile connection 23 in FIG. 1 and mobile connections 45 , 46 and 44 in FIG. 2 are any connections that allow the mobile devices 21 to communicate over the Internet. For example, the connections 23 , 44 , 45 and 46 may be through landlines, cellular channels, 802.11 wireless channels, satellite channels, etc.
Continuous Real-Time Connectivity
Referring specifically to FIG. 1 , the personal client 40 automatically establishes a continuous connection 25 between the PC 38 and management server 28 . The personal client 40 initiates an outbound connection 25 which is then authenticated by the management server 28 . For example, the client 40 presents an authentication token 29 to the management server 28 . The management sever 28 then attempts to match the information in the authentication token 28 with information in user database 42 .
If the authentication token 29 is authenticated, the connections 25 or 48 are established through the firewall 31 to achieve access to the management server 28 which is outside the private enterprise network 18 . The management server 28 then sends the personal client 40 connection authorization and any other needed information. For example, the management server 28 may send back connection sharing information, email notification filters, and other mobile communication configuration parameters associated with a particular user.
The management server 28 and the personal client 40 then go into a quiescent mode until a transaction, such as a data query, is transferred between the mobile device 21 and the personal client 40 . If for any reason the connection 25 is disconnected, the personal client 40 automatically establishes another connection 25 with management server 28 .
It is important to note that the connection 25 is continuously maintained even when no connection 23 is currently exists between mobile device 21 and management server 28 . In one embodiment, the connection 25 is a Transmission Control Protocol/Internet Protocol (TCP/IP) connection. However, any connection protocol can be used that allows continuous connectivity between the enterprise network 18 and communication management system 16 .
In an alternative embodiment, the connection 25 may be established through a proxy server (not shown) in enterprise network 18 . For example, messages sent by the personal client 40 may be encrypted by the proxy server with a Secure Sockets Layer (SSL).
After the connection 25 is established by the personal client 40 , a mobile connection 23 can be established at any time between the mobile device 21 and the management server 28 . After the mobile connection 23 is established, the mobile device 21 can then access email and other information in the email server 34 or memory 39 through personal client 40 . Thus, after connection 25 is established, the personal client 40 effectively operates as an email server for the mobile device 21 .
Referring to FIG. 2 , in a manner similar to the personal client 40 , an enterprise client 41 establishes a continuous connection 48 with the management server 48 similar to the connection 25 established between the personal client 40 and management server 28 . The connection 48 is used for relaying transactions between multiple mobile devices 21 and multiple email users on enterprise server 34 at the same time.
In the version of the communication architecture shown in FIG. 2 , the personal client 40 may establish connection 25 with the management server 28 through PCS 32 and certain mobile devices 24 may establish mobile connections 44 through the SDS 30 .
Mobile Device Log-In
Referring to FIGS. 1 and 2 , the management server 28 authenticates mobile connections 23 , 44 , 45 , and 46 initiated by the mobile devices 21 . When a user signs up for a mobile account, a copy of the user's username and password for the enterprise network 18 is stored in the user database 42 . After the mobile device 21 powers on, the user is required to login to the communication management system 16 by entering another user name and password. If the mobile device 21 accesses email through the enterprise server 34 , as opposed to through the PC 38 , then an enterprise identifier (e.g., name) may also be required.
The mobile device 21 sends an authentication token 27 either directly to the management server 28 or to the SDS 30 which forwards the authorization token 27 to the management server 28 . The management server 28 verifies information in the authorization token 27 with information in the user database 42 . If the authentication token 27 is verified, the management server 28 sends an authorization acknowledgement directly to the mobile device 21 or through the SDS 30 .
Once the mobile device 21 has successfully logged in, the management server 28 unlocks the user's enterprise user name and password. This allows the mobile device 21 to access email and other local files in the enterprise network 18 either through connection 25 or connection 48 .
The management server 28 also conducts rendering and view functions needed for presenting email and other data to the different mobile devices 21 . For example, the management server 28 reformats local data retrieved from the enterprise network 18 according to the particular mobile device 21 requesting the information. The management server 28 also operates as a transactional routing engine for routing transactions between the mobile devices 21 and the enterprise network 18 .
Stateless Non-Replicated Connectivity
Referring to FIG. 3 , once the mobile device 21 has successfully logged in, stateless connectivity exists between the mobile device 21 and the personal client 40 over connections 23 and 25 . For example, the mobile device 21 may send a transaction request 62 to the personal client 40 to view emails in the users mailbox 60 .
The transaction request 62 is sent from the mobile device 21 to the management server 28 over mobile connection 23 . The management server 28 locates the personal client 40 associated with request 62 and forwards the request 62 over the appropriate connection 25 . The personal client 40 accesses data in mailbox 60 according to the transaction request 62 . For example, if the transaction request 62 requests viewing the user's latest emails, the personal client 40 generates an email list 64 containing the emails received in mailbox 60 . The personal client 40 then sends the email list 64 back to the mobile device 21 through connection 25 .
If the mobile device 21 has limited memory or viewing capability, only a latest portion of the emails in mailbox 60 may be included in email list 64 . Alternatively, the personal client 40 may send all of the emails in mailbox 60 to the management server 28 . The management server 28 then doles out portions of the email list 64 to the mobile device 21 according to the type of electronic platform used by the mobile device 21 .
These transactions allow the mobile device 21 to view information in mailbox 60 in real time without having to maintain a second version of the emails in mailbox 60 . Once the connection 23 is terminated, the email list 64 received by the mobile device 21 may be deleted. If emails in mailbox 60 need to be viewed again, the mobile device 21 sends a new transaction request 62 to the personal client 40 .
If the items requested in transaction 62 are too numerous or too large for viewing by the mobile device 21 , the personal client 40 may send only enough information in list 64 to identify the items. For example, the personal client 40 may glean out from an email the email sender information, when the email was sent, and the subject line. The personal client 40 may only send out this gleaned information for the latest emails received in mailbox 60 .
The mobile device 21 receives the gleaned partial list 64 and can then select one or more of the items in list 64 for viewing. Depending on the type of data requested for viewing, another transaction request 62 may be sent from mobile device 21 to personal client 40 to view the selected email in its entirety. The personal client 40 then sends any remaining contents of that selected email to the mobile device 21 . Alternatively, if the gleaned partial email list 64 does not contain the email that the mobile device user wishes to view, the mobile device 21 can send another transaction request 62 to the personal client 40 to view a second portion of the emails contained in mailbox 60 .
After the transaction between the mobile device 21 and the management server 28 is completed, no emails from mailbox 60 , or any other files from the PC 38 need to remain on the mobile device 21 . That is unless the mobile device 21 saves a copy of the data. Thus, the servers 28 , 30 and 32 and the mobile devices 21 shown in FIGS. 1-2 do not have to maintain a second version of the email data in mailbox 60 .
This stateless connectivity does not require the large number of transactions that are typically required in store and forward architectures and also eliminates having to copy emails and send the copies to the mobile device each time an email is received at the user's mailbox.
Local Data File Access
FIG. 4 shows how the mobile device 21 accesses local files contained on the PC 38 and attaches those local files to email messages. The personal client 40 operating on PC 38 is initially configured to point to a root directory 80 . The root directory 80 may include multiple subfolders 82 that contain files 84 and 86 . Other files 88 and 90 may be located at the top level of the root directory 80 or located in other subfolders.
Some mobile devices 21 may not have the capability to actually open and read the files in root directory 80 or there may be too much data in certain files for the mobile device 21 to store. In these situations, the mobile device 21 can still view, navigate and select folders and files located under the root directory 80 .
An email message 70 is opened on the mobile device 21 . An Insert File option may then be selected in the email application running on the mobile device 21 . Selecting the Insert File option sends a view files transaction 76 from the mobile device 21 to the management server 28 .
The management server 28 sends the transaction 76 over the appropriate connection 25 to personal client 40 . The personal client 40 receives the transaction 76 and determines the mobile device 21 has requested a list of files in root directory 80 . The personal client 40 generates a response containing a file list 78 identifying the subfolders 82 and files 84 - 90 in root directory 80 . The response message containing file list 78 is then sent back to the mobile device 21 over connection 25 .
All or part of the file list 78 may be sent to mobile device 21 . For example, the management server 28 may determine the mobile device 21 has insufficient memory to view the entire file list 78 . The management server 28 could also determine it would take too much time to send the entire file list 78 to the mobile device 21 . In these cases, the management server 28 may only send a portion of the file list 78 to the mobile device 21 .
The mobile device 21 displays the file list 78 received from the management server 28 and selects any of the listed files or subfolders. A subfolder in the file list 78 may be selected that contains files not included in the file list 78 . This causes the mobile device 21 to send out another view file transaction 76 to the management server 28 requesting a list of the files contained in the selected subfolder. The management server 28 , or personal client 40 , then sends back another file list 78 containing the files in the selected subfolder.
If one or more files are selected from the file list 78 , an associated file identifier 72 is inserted into the email message 70 . In one example, selecting files is equivalent to a Hypertext Markup Language (HTML) forms submission where an item is selected from a website. When an email Send command is selected on the mobile device 21 , an email transaction 74 is sent to the management server 28 that includes email message 70 and file identifier 72 .
The management server 28 sends the email transaction 74 through connection 25 to the personal client 40 . In the enterprise network shown in FIG. 2 , the email transaction 74 may travel from the SDS 30 to the management server 28 and then through the PCS 32 and connection 25 to the personal client 40 .
The personal client 40 unwraps the email transaction 74 and extracts the email message 70 containing the file identifier 72 . The personal client 40 reformats the email message 70 into an email message 92 and then attaches the file in root directory 80 corresponding to file identifier 72 . The email message 92 with the attached file is then sent by the personal client 40 to the email server 34 . A copy of the email message 92 may also be copied to the Sent Items folder in the user's mailbox.
Storing Queries
Referring to FIG. 5 , some mobile devices 21 referred to as smart mobile devices may include software that operates a mobile client 98 that receives and transmits data. The mobile device 21 can store another version of the local data in email server 34 . The stored data can include contact information stored in memory section 100 , emails stored in memory section 102 and calendar information stored in memory section 104 . The mobile device 21 can view, generate emails, and generally manipulate the data in memory section 100 - 104 off-line.
The mobile client 98 can maintain a latest version of queried data in memory section 100 - 104 using the stateless connectivity architecture described above. For example, when a View Contacts operation is initiated on the mobile device 21 , the mobile client 98 sends a view contacts transaction 106 to the personal client 40 . The mobile device 21 may have requested the contacts list 114 for the entire enterprise network. If the contacts list 114 is too large to send to the mobile device 21 , the personal client 40 may only send back a first portion 108 of the contacts list. For example, a list of contacts for the first few letters of the alphabet.
If the contact the user is looking for is not within the first contacts list portion 108 , the user can send a second View Contacts transaction 110 to the personal client 40 . The second transaction 110 may identify a specific letter of the alphabet for the personal client 40 to query. Alternatively, the transaction 110 may direct the personal client 40 to send back a next portion of the enterprise contact list 114 immediately following contacts list portion 108 . The personal client 40 sends back a second portion 112 of contact list 114 pursuant to the transactions 110 . If the contact the user is looking for is in the second contact list portion 112 , no further queries are sent from the mobile device 21 .
The mobile client 98 can store the last received contact list portion 112 in memory 100 . According to the amount of memory available in the mobile device 21 , the mobile client 98 may save the last few contact list portions 112 and 108 in memory 100 . Thus, when the mobile device 21 goes off-line, a user is still able to view the latest information received from personal client 40 . The mobile client 98 can also save the most recent email queries in memory space 102 and the most recent calendar queries in memory space 104 .
Synchronization
Referring to FIG. 6 , the mobile device 21 may store a second version 122 of the user's local data. It may be necessary from time to time to synchronize the second version 122 on the mobile device 21 with the local version 136 on the email server 34 . In one embodiment, the mobile device periodically sends out synchronization requests 134 to the personal client 40 . The personal client 40 generates a response 133 pursuant to the synchronization request 134 that contains the latest emails, or other local user data. The response 133 is sent back to the mobile device 21 and is used for updating data 122 .
Triggers can be used to notify the mobile device 21 when new emails arrive on the email server 34 . Filters 138 are configured in the personal client 40 that identify the types of emails or other types of events that cause the mobile device 21 to send a trigger 132 .
For example, the filters 138 may tell the personal client 40 to send a trigger 132 each time a new email arrives in the user's mailbox. The personal client 40 monitors the user's mailbox in email server 34 for new emails. If a new email is detected, the personal client 40 sends a trigger 132 to the mobile device 21 through the management server 28 . The trigger 132 may be a message with no payload that simply tells the mobile device 21 that something new has happened in the user's mailbox. The trigger 132 causes the mobile device 21 to establish the mobile connection 23 with the management server 28 and then send a synchronization request transaction 134 to the personal client 40 .
In one implementation, Short Message Service (SMS) messages 126 are used to trigger the mobile device 21 into establishing the mobile connection 23 and send the synchronization request transaction 134 . The management server 28 is coupled through a notification gateway 130 to a Short Message Service Controller (SMSC) 128 operated by a mobile communication service carrier. In other implementations, some other notification protocol, such as a Wireless Application Protocol (WAP) Push is used to trigger the mobile device 21 .
The personal client 40 generates the trigger message 132 whenever an event associated with the user's mailbox 136 corresponds with an event identified in filters 138 . The trigger message 132 causes the management server 28 to send a message through the notification gateway 130 to the SMSC 128 . The SMSC 128 accordingly sends the SMS message 126 to the mobile device 24 .
The mobile device 21 monitors for particular SMS messages having some particular computer readable content. When SMS message 126 is received having that particular content, the mobile device 21 initiates a mobile connection with management server 28 . The mobile device 21 may extract the SMS message 126 from a user queue before a user has a chance to see it.
The mobile device 21 initiates an authentication process with the management server 28 . After successful authentication, the synchronization request 134 is sent from the mobile device 21 to the management server 28 . The management server 28 transfers the request 134 to the personal client 40 over the previously established connection 25 . The personal client 40 upon receiving the synchronization request 134 sends back a response 133 that includes a list of the latest emails in the user's mailbox 136 .
High Priority Email
Still referring to FIG. 6 , the connection architecture shown above can also be used for providing notification of high priority emails. The personal client 40 may be configured to monitor the email server 34 for particular types of email messages. For example, the filters 138 may cause the personal client 40 to look for any emails sent from a particular sender email address. For example, email sent from the user's supervisor.
Whenever an email arrives in the user's mailbox 136 sent from the supervisor's email address, the personal client 40 sends a stripped down version of that email through the management server 28 to the SMSC 128 . For example, the stripped down version may only identify the sender, time, date, and subject line for the email message. The SMSC 128 then sends a SMS high priority message 124 to the mobile device 24 .
The stripped down high priority SMS message 124 may be slightly different than the SMS message 126 used for triggering mobile device synchronization. For example, the SMS message 126 may not contain any email content, while the priority message 124 includes some portion of the actual email content received in mailbox 136 . The high priority message 124 can be sent to any SMS capable mobile device.
Power Management
The mobile device 21 can periodically initiate synchronization according to an amount of charge remaining in a battery 123 . For example, when battery 123 has a relatively large amount of charge remaining, the mobile device 21 may synchronize more frequently than when the battery 123 has a relatively small amount of charge remaining. Systems for determining an amount of charge remaining in battery are well known and are therefore not described in further detail.
Different charge gradient levels can be used for varying how often the mobile device 21 synchronizes with the personal client 40 . For example, the mobile device 21 may synchronize every 5 minutes when the battery 123 has 75% or more charge remaining and may synchronize every 10 minutes when the battery 123 is between 75% and 50% charged. When the battery 123 is between 50% and 25% charged, the mobile device 21 may only synchronize with personal client 40 every 30 minutes. Other charge/synchronization rates can also be used.
To further conserve power, synchronization can be varied according to the day of the week. For example, the mobile device 21 may synchronize less often on weekends than on weekdays.
SUMMARY
The system described above can use dedicated processor systems, micro controllers, programmable logic devices, or microprocessors that perform some or all of the operations. Some of the operations described above may be implemented in software and other operations may be implemented in hardware.
For the sake of convenience, the operations are described as various interconnected functional blocks or distinct software modules. This is not necessary, however, and there may be cases where these functional blocks or modules are equivalently aggregated into a single logic device, program or operation with unclear boundaries. In any event, the functional blocks and software modules or features of the flexible interface can be implemented by themselves, or in combination with other operations in either hardware or software.
Having described and illustrated the principles of the invention in a preferred embodiment thereof, it should be apparent that the invention may be modified in arrangement and detail without departing from such principles. We claim all modifications and variation coming within the spirit and scope of the following claims.
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A real-time communication architecture establishes a continuous connection between an enterprise network and a communication management system. The connection is continuously held open allowing mobile devices real-time access to enterprise email systems. The real-time communication architecture can support an entire enterprise email system or individual email users. The foregoing and other objects, features and advantages of the invention will become more readily apparent from the following detailed description of a preferred embodiment of the invention which proceeds with reference to the accompanying drawings.
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This is a division of pending application Ser. No. 312,367, filed Feb. 15, 1989, now abandoned incorporated herein by reference, which is a division of application Ser. No. 191,312, filed May 6, 1988, now U.S. Pat. No. 4,912,254, which is a division of application Ser. No. 872,561, filed Jun. 10, 1986, now U.S. Pat. No. 4,749,804, which is a division of application Ser. No. 602,834, filed Apr. 23, 1984, now U.S. Pat. No. 4,605,758, which is a continuation of application Ser. No. 329,672, filed Dec. 11, 1981, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for preparing pharmaceutically useful α-arylalkanoic acids. In particular, it relates to a stereoselective process for producing optically active α-arylalkanoic acids which are substantially optically pure.
2. State of the Art
Numerous α-arylalkanoic acids (i.e. 2-arylalkanoic acids) have been described, developed and found to be useful as pharmaceutical agents exhibiting anti-inflammatory, analgesic and anti-pyretic activity. For example, U.S. Pat. No 3,385,386, describes certain 2-phenylpropionic acids useful for their anti-inflammatory activity. Particularly noteworthy of the compounds described therein is 2-(4-isobutylphenyl)-propionic acid, known generically as ibuprofen. U.S. Pat. No. 3,600,437 describes 2-(3-phenoxyphenyl)- and 2-(3-phenylthiophenyl)alkanoic acids among other related compounds. Particularly noteworthy therein is the compound 2-(3-phenoxyphenyl)propionic acid, which is known generically as fenoprofen. U.S. Pat. No. 3,624,142 describes (fluoro-substituted biphenyl)alkanoic acids, among which is 2-(4'-fluoro-4-biphenylyl)propionic acid. U.S. Pat. No. 3,755,427 describes additional fluoro-substituted biphenylpropionic acids, among which is 2-(2-fluoro-4-biphenylyl)propionic acid, known as flurbiprofen. U.S. Pat. No. 3,904,682 describes the compound 2-(6-methoxy-2-naphthyl)propionic acid, the d-isomer of which is known generically as naproxen and is a potent anti-inflammatory compound. Related compounds are described in Belgian Patent No. 747,812. U.S. Pat. No. 3,912,748 describes 5- and 6-benzoxyazoylalkanoic acids possessing anti-inflammatory, anti-pyrretic and analgesic activity. Notable among those compounds is 2-(4-chlorophenyl-5-benzoxazoyl)-propionic acid, known generically as benoxaprofen. Thus, it can be seen that a tremendous variety of useful α-arylalkanoic acids are known.
Other known, useful α-arylalkanoic acids are exemplified by 6-chloro-α-methyl-9H-carbazole-2-acetic acid (carprofen), α-methyl-9H-fluorene-2-acetic acid (cicloprofen), 3-chloro-α-methyl-4-(2-thienylcarbonyl)-benzene acetic acid (cliprofen), α-methyl-3-phenyl-7-benzofuranacetic acid (furaprofen), 4-(1,3-dihydro-1-oxo-2H-isoindol-2-yl)benzene acetic acid (indoprofen), 3-benzoyl-α-methylbenzene acetic acid (ketoprofen), 3-chloro-4-(2,5-dihydro-1H-pyrrol-1-yl)benzeneacetic acid (pirprofen), α-methyl-4-(2-thienylcarbonyl)benzeneacetic acid (suprofen) and compounds related thereto. Additionally, certain pyrethroid-type insecticides utilize optically active α-arylalkanoic acids, e.g. α-(4-chlorophenyl)isovaleric acid, α-(4-difluoromethoxyphenyl)isovaleric acid and the like, in their formulations.
Numerous processes for the manufacture of such α-arylalkanoic acids have also been described. Such processes have been described in the aforementioned patents, in other patents and in the non-patent literature as well. For example, U.S. Pat. No. 4,135,051 describes a process for preparing the ester precursors of many of the useful arylalkanoic acids utilizing trivalent thallium salts as reactants. Such a process suffers from the disadvantage that the thallium salts employed are toxic chemicals which must be removed from the final product. U.S. Pat. No. 3,975,431 describes the preparation of α-arylalkanoic acids from glycidonitriles through enol acylates U.S. Pat. Nos. 3,658,863; 3,663,584; 3,658,858; 3,694,476; and 3,959,364 describe various coupling methods for preparing arylalkanoic acids. More recently, U.K. Patent publication No. 2,042,543 published Sep. 24, 1980, (corresponding to application Serial No. 8005752, filed Feb. 20, 1980) describes a process for preparing the ester precursor of arylalkanoic acids from α-haloalkyl aryl ketones using a metal catalyst for catalytically inducing rearrangement in an acidic, alcoholic medium, the catalyst being silver (I) salts of organic and/or inorganic anions. The high costs associated with utilizing metal catalysts, particularly silver, in a large scale process is an inherent disadvantage to such a process. European Patent Application No. 81200210.3, filed Feb. 23, 1981 (Publication No. 0034871, published Sep. 2, 1981) describes a process for preparing esters of α-arylalkanoic acids via rearrangement of α-haloketals in the presence of a Lewis acid (including, for example, copper and zinc salts and the like). Additionally, a recent article in Tetrahedron Letters, Vol. 22, No. 43, pp 4305-4308 (1981) describes a process for producing α-arylalkanoic acids by 1,2-rearrangement of the aryl group via hydrolysis of α-sulfonyloxy acetals.
While the aforesaid processes are useful in many respects, there remains a need for a simple, economical process for producing α-arylalkanoic acids of the types described. Furthermore, in view of the optically active nature of numerous of the α-arylalkanoic acids, it is advantageous to have a stereoselective process for producing the desired optically active isomer of the α-arylalkanoic acids which displays all or the major portion of the pharmaceutical activity. For example, the isomer d 2-(6-methoxy-2-naphthyl)propionic acid is more pharmaceutically active than the corresponding 1-isomer, and, accordingly, it is desireable to have a stereoselective process for producing the d-isomer directly. Such a process obviates the necessity of subsequently resolving the d- and 1-isomers. The elimination of the resolution steps results in substantial economic savings, both in material cost and manufacturing labor and plant usage. These savings are particularly significant with regard to those compounds which are approved for pharmaceutical use as a substantially pure, optically active isomer [e.g. d 2-(6-methoxy-2-naphthyl)propionic acid].
SUMMARY OF THE INVENTION
The present invention is directed to a process for producing an optically active α-arylalkanoic acid or an ester, ortho ester or amide thereof comprising contacting an organometallic compound, e.g. an aryl magnesium Grignard reagent, with an acyl halide, an acyl amine or an acid anhydride, the acyl halide, acyl amine or acid anhydride being substituted with a leaving group or a group which can be converted into a leaving group. In one aspect, the present invention comprises contacting an aryl organometallic halide with an optically active α-substituted acyl halide, acyl amine or acid anhydride to form the corresponding optically active aryl alkyl ketone, wherein the α-substituent is a leaving group. The ketone group then is ketalized and the substrate formed is rearranged and hydrolyzed to the desired optically active α-arylalkanoic acid. During the rearrangement step of the process, the leaving group disassociates from the substrate and the aryl group migrates to the α-position to afford the rearranged, optically active α-arylalkanoic acid. That aspect of the invention is exemplified by the contacting of an aryl magnesium Grignard reagent with an optically active α-sulfonyloxy acyl halide to form the corresponding aryl α-sulfonyloxyalkyl ketone.
The optically active ketones and ketals so produced represent an additional aspect of the present invention. By alternative processes, those ketones can be converted into the desired optically active α-arylalkanoic acids listed previously.
In one embodiment of the invention, the optically active ketones produced are subjected to ketalization under conditions which are amenable to retaining the desired stereochemical configuration at the asymmetric carbon atom of the ketone. For example, ketalization of the ketone with an ortho ester under conditions of acid catalysis affords the desired optically active ketal with retention of the desired configuration at the asymmetric carbon atom. Subsequent solvolytic rearrangement of the ketal yields the desired α-arylalkanoic acid, or the ester, ortho ester or amide thereof. By appropriate choice of the optical configuration of the substituted acyl halide, or the acyl amine or acid anhydride, in view of the single inversion during the rearrangement step, it is possible to produce a desired optically active α-acylalkanoic acid.
The optically active ketone described above can also be subjected to a ketalization process which results in inversion of configuration at the asymmetric carbon atom of the ketone. For example, treatment of the ketone with alkali metal alkoxides or aryloxides typically affords a ketal in which the absolute configuration at the asymmetric carbon atom has inverted. Subsequent solvolytic rearrangement results in an additional inversion at the asymmetric carbon atom to produce the other optically active isomer of the desired α-arylalkanoic acid, or an ester, ortho ester or amide thereof, assuming that the starting ketone in both instances is the same. However, by appropriately choosing the absolute configuration of the starting acyl halide, acyl amine or acid anhydride, it is possible to cause the reaction sequence to yield the desired α-arylalkanoic acid in each instance.
In a further embodiment, the optically active ketone described above can be reduced to the corresponding arylalkanol, and then subjected to solvolytic rearrangement to afford the rearranged aldehyde. The aldehyde then can be converted to the desired optically active α-arylalkanoic acid by oxidation methods which are conventional in the art.
In one aspect, the present invention is directed to a process for producing a compound of the formula: ##STR1## which comprises contacting an organometallic compound of the formula:
ArMX, (Ar).sub.2 M or ArM'
with an acyl halide, an acyl amine or an acid anhydride of the formula: ##STR2## wherein Ar is aryl, M is cadmium, copper(II), manganese, magnesium or zinc, M' is copper(I) or lithium, R 1 is alkyl or cycloalkyl, X is halogen, Y is halogen or a group of the formula: ##STR3## wherein R' and R" are alkyl or aryl or when taken together with N form a heterocyclic moiety which optionally can contain other hetero atoms on the ring, or acyloxy, and Z is a leaving group or a group that can be converted to a leaving group. Within that aspect of the invention, the presently preferred embodiment is characterized by use of an organometallic compound of the formula ArMX, preferably a magnesium Grignard reagent, and an acyl halide wherein Z is halogen or a group of the formula: ##STR4## wherein R 2 is alkyl, cycloalkyl, alkenyl, alkynyl, aryl or arylalkyl. When Ar is 6-methoxy-2-naphthyl, the utilization of an optically active substituted acyl halide is desirable.
In another aspect, the present invention is directed to a process for producing a single stereoisomer of a compound of the formula: ##STR5## in the substantial absence of any other stereoisomer of the compound, which comprises contacting an organometallic compound of the formula:
ArMX, (Ar).sub.2 M or ArM'
with an optically active acyl halide, an acyl amine or an acid anhydride of the formula: ##STR6## wherein Ar, M, M', R 1 , X, Y and Z are as defined above.
In still another aspect, the invention is directed to a process for producing a single stereoisomer of a ketal of a compound of the formula: ##STR7## in the substantial absence of any other stereoisomer of the ketal, the single stereoisomer of the ketal having a preselected absolute configuration, which comprises contacting a stereoisomer of the compound having the preselected absolute configuration in the substantial absence of any other stereoisomer of the compound with a ketalizing agent effective to maintain the preselected absolute configuration, wherein Ar, R 1 and Z are as defined above. That aspect of the invention is particularly characterized by conducting the ketalization with a trialkyl ortho ester such as trimethyl orthoformate or a polyhydric alcohol such as ethylene glycol in the presence of an acid catalyst.
In another aspect, the invention is directed to a process for producing an α-arylalkanoic acid of the formula: ##STR8## or an ester, ortho ester or amide thereof which comprises:
contacting a compound of the formula:
ArMX, (Ar).sub.2 M or ArM'
with an acyl halide, an acyl amine or an acid anhydride of the formula: ##STR9## to form a ketone of the formula: ##STR10## wherein Ar, M, M', R 1 , X, Y and Z are as defined above;
contacting the ketone with a ketalizing agent effective to form a first ketal of the formula: ##STR11## wherein R 5 and R 6 are alkyl, aryl or aralkyl, optionally the same or different, or, when taken together, alkylene having 2-8 carbon atoms;
regenerating a leaving group at the α-position of the first ketal to form a second ketal of the formula: ##STR12##
rearranging the second ketal to the α-arylalkanoic acid, or an ester, ortho ester or amide thereof; and
optionally hydrolyzing any ester, ortho ester or amide formed to the corresponding α-arylalkanoic acid.
In yet another aspect, the invention is directed to a process for producing a stereoisomer of an α-arylalkanoic acid of the formula ##STR13## or an ester, ortho ester or amide thereof in the substantial absence of any other stereoisomer of the α-arylalkanoic acid, ester, ortho ester or amide thereof which comprises: contacting a compound of formula:
ArMX, (Ar).sub.2 M or ArM'
with an optically active acyl halide, acyl amine or acid anhydride of the formula: ##STR14## to form a single stereoisomer of an aryl alkyl ketone of the formula: ##STR15## in the substantial absence of any other stereoisomer of the aryl alkyl ketone, wherein Ar, M, M', R 1 , X, Y and Z are as defined above;
ketalizing the single stereoisomer of the aryl alkyl ketone to form a single stereoisomer of an aryl alkyl ketal thereof in the substantial absence of any other stereoisomer of the aryl alkyl ketal;
rearranging the single stereoisomer of the aryl alkyl ketal to form a single stereoisomer of the α-arylalkanoic acid or of an ester, ortho ester or amide thereof, in the substantial absence of any other stereoisomer of the α-arylalkanoic acid, ester, ortho ester or amide thereof; and
optionally hydrolyzing any ester, ortho ester or amide formed to the corresponding α-arylalkanoic acid.
Presently preferred leaving groups exemplified by Z are halogen or the group: ##STR16## wherein R 2 is alkyl, cycloalkyl, alkenyl, alkynyl, aryl or arylalkyl.
In yet another aspect, the invention is directed to a process for producing a stereoisomer of an α-arylalkanoic acid of the formula: ##STR17## or an ester, ortho ester or amide thereof in the substantial absence of any other stereoisomer of the α-arylalkanoic acid, or the ester, ortho ester or amide thereof which comprises:
contacting a compound of the formula:
ArMX, (Ar).sub.2 M or ArM'
with an optically active acyl halide, acyl amine or acid anhydride of the formula: ##STR18## to form an optically active ketone of the formula: ##STR19## wherein Ar, M, M', R 1 , X, Y and Z are as defined above;
contacting the ketone with a ketalizing agent effective to form an optically active first ketal of the formula: ##STR20## wherein R 5 and R 6 are alkyl, aryl or aralkyl, optionally the same or different, or, when taken together, alkylene having 2-8 carbon atoms;
regenerating a leaving group at the α-position of the first ketal to form an optically active second ketal of the formula: ##STR21##
rearranging the optically active second ketal to the stereoisomer of the α-arylalkanoic acid, or an ester, ortho ester or amide thereof; and
optionally hydrolyzing any ester, ortho ester or amide formed to the corresponding α-arylalkanoic acid.
In still another aspect, the present invention is directed to optically active ketones having an absolute (S)-configuration of the formula: ##STR22## wherein Z is halogen, hydroxy, acetoxy, benzoyloxy, dihydropyranyloxy, trialkylsiloxy or the group: ##STR23## wherein R 2 is alkyl, cycloalkyl, alkenyl, alkynyl, aryl or arylalkyl.
In still another aspect, the invention is directed to optically active ketals having an absolute (S)-configuration of the formula: ##STR24## wherein R 3 and R 4 are alkyl, optionally the same or different, or, when taken together, are alkylene having 2-8 carbon atoms, and Z is halogen, hydroxy, acetoxy, benzoyloxy, dihydropyranyloxy, trialkylsiloxy or the group ##STR25## wherein R 2 is alkyl, cycloalkyl, alkenyl, alkynyl, aryl or arylalkyl, with the provision that when R 3 and R 4 are methyl, R 2 is not d-10-camphoryl.
DETAILED DESCRIPTION OF THE INVENTION
The process of this invention utilizes as starting materials organometallic compounds of the formula:
ArMX, (Ar).sub.2 M or ArM' (I)
wherein Ar is an aryl moiety, M is cadmium, copper(II), manganese, magnesium or zinc, M' is copper (I) or lithium, and X is a halogen atom. Other starting materials useful in the present invention are substituted acyl halides, acyl amines or acid anhydrides, which may be racemic compounds or optically active compounds, of the general formula: ##STR26## wherein R 1 is alkyl or cycloalkyl, Y is halogen, a group of the formula: ##STR27## wherein R' and R" are alkyl or aryl or when taken together with N form a heterocyclic moiety which optionally can contain other hetero atoms in the ring, or acyloxy, and Z is a leaving group or a group that can be converted to a leaving group. Presently preferred leaving groups are those in which Z is halogen or a group of the formula: ##STR28## wherein R 2 is alkyl, cycloalkyl, alkenyl, alkynyl, aryl or aralkyl.
For the purposes of this invention, alkyl includes straight or branched chain aliphatic groups having 1-18 carbon atoms as exemplified by methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, amyl, hexyl, heptyl, octyl, decyl, dodecyl and octadecyl. Those alkyl groups having 1-8 carbon atoms, and especially those having 1-4 carbon atoms, are presently preferred. Alkenyl groups include those having 2-8 carbon atoms, both straight and branched chain, as exemplified by vinyl, allyl, methallyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, and isomeric forms thereof. The alkynyl groups include those having 2-8 carbon atoms, both straight chain and branched, as exemplified by ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl, octynyl and isomeric forms thereof. Cycloalkyl groups include those having 3-15 carbon atoms as exemplified by cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, 1-cyclohexenyl, methylcyclohexenyl cycloheptyl, cyclooctyl, cyclodecyl, cycloundecyl, cyclododecyl and cyclopentadecyl. The cycloalkyl groups having 3-8 carbon atoms are presently preferred. The aryl and aralkyl groups comprehended are aromatic groups generally as exemplified by tolyl, xylyl, benzyl, phenethyl, phenylpropyl, benzhydryl, and the like, as well as fused and bridged ring structures, such as d- 10-camphoryl, indanyl, indenyl, naphthyl, naphthylmethyl, acenaphthyl, phenanthyl, cyclopentanopolyhydrophenanthyl, adamantanyl, bicyclo[3:1:1]heptyl, bicyclo[2:2:2]octyl and the like. All of the above can either be unsubstituted or substituted with one or more non-interfering substituents, such as hydroxy or hydroxy derivatives; alkoxy such as methoxy, ethoxy, propoxy, butoxy, and the like; acyloxy, such as acetoxy, propionoxy, butyroxy and the like; nitro groups; alkylamino groups such as dimethylamino and the like; halogens, such as fluorine, chlorine, iodine or bromine; carbonyl derivatives such as enol ethers and ketals; and the like.
The acyloxy groups include those derived from saturated and unsaturated carboxylic acids, carbocyclic carboxylic acids and heterocyclic carboxylic acids. They include, by way of example, straight or branched chain aliphatic groups having 1-18 carbon atoms such as acetoxy, propionyloxy, butyryloxy, isobutyryloxy, palmitoyloxy, stearoyloxy and the like. Also included are the unsaturated aliphatic groups such as acryloyloxy, propioloyloxy, crotonoyloxy, oleoyloxy and the like. Examples of those group derived from the carbocyclic carboxylic acids are benzoyloxy, 2-naphthoyloxy, toluoyloxy, cinnamoyloxy and the like. Examples of those groups derived from heterocyclic carboxylic acids are 3-furoyloxy, 2-thenoyloxy, nicotinoyloxy, isonicotinoyloxy and the like. The acyloxy groups optionally can be substituted with non-interfering substituents, which may include substituents represented by Z as defined herein.
The heterocylic moieties formed by the group ##STR29## when R' and R" are taken together with N, include 5-6 membered ring structures where N is a ring member. Those groups are exemplified by 1-pyrrolyl, 1-imidazolyl, 1-pyrazolyl, 1-piperidyl and the like, or fused ring compounds such as 1-indolyl, 1-H-indazol-1-yl, 3-H-indol-1-yl and the like. The heterocyclic moieties may optionally include other hetereo atoms such as oxygen and sulfur. Included therein are morpholino and thiazolyl groups.
The aryl moieties comprehended by Ar include aryl and aralkyl groups generally as described above. The aryl groups include carbocyclic radicals having from 6 to 20 carbon atoms. The carbocyclic radicals may be monocyclic as represented by the phenyl radical or they may be condensed having at least two rings with at least two carbon atoms in common. Examples of condensed aryl radicals are the naphthyl, the indenyl, the anthryl, the acenaphthyl, the indanyl and the biphenyl radicals and the like. The carbocyclic radicals can carry additional substituents, for example 1 to 3 lower alkyl radicals and/or lower alkoxy radicals and/or an alkanoyl radical with up to 12 carbon atoms and/or 1 to 3 halogen atoms, more particularly 1 to 3 fluorine, chlorine or bromine atoms and/or an aroyl radical with up to 12 carbon atoms and/or a nitro group. In addition the carbocyclic radicals can also comprise saturated or unsaturated isocylic rings. Examples of unsaturated isocyclic radicals are the phenyl, cyclohexenyl, cyclopentenyl and the naphthyl radicals. Examples of the saturated isocyclic radicals are the cyclohexyl, cyclopentyl, cycloheptyl and the cyclopropyl radicals. Additionally, the carbocyclic radicals may be linked to one or more (up to 4) rings directly by simple bonds to form a ring assembly in accordance with IUPAC Rule A-51. Such a ring assembly may include 5 to 26 carbon atoms, including the carbon atoms of the substituents. Examples of such carbocyclic ring structures include the 4-cyclohexylphenyl, the 4-biphenyl, the 3-biphenylyl, the 5-cyclohexyl-1-indanyl, the 4-(1-cyclohexen-1-yl)phenyl and the 5-phenyl-1-naphthyl radicals and the like. Those ring assemblies can carry from 1 to 3 substituents such as described above. In particular, the aryl moieties comprehended include those of acid products such as exemplified in U.S. Pat. Nos. 3,385,386; 3,660,437; 3,624,142; 3,755,427; 3,904,682; and 3,912,748 and Belgian Patent No. 747,812. Described therein are substituted or unsubstituted phenyl, phenoxyphenyl, naphthyl or biphenyl groups, such as represented by 3-phenoxyphenyl, 2-fluoro-1,1'-biphenylyl, 4-isobutylphenyl, 4'-fluoro-4-biphenylyl, 6-methoxy-2-naphthyl, 5-bromo-6-methoxy-2-naphthyl and 4-chlorophenyl-5-benzoxazoyl.
The halogens comprehended herein are bromine, chlorine, fluorine and iodine, with bromine and chlorine being presently preferred.
Z may itself be a leaving group or a group which is convertible to a leaving group. Leaving groups include the anions of inorganic and organic acids.
Those groups are sufficiently labile to disassociate from the substrate upon and/or by contacting of the substrate with a Lewis acid, an agent having an affinity for oxygen or a protic or dipolar aprotic solvent during rearrangement of the aryl α-substituted alkyl ketal to the α-arylalkanoic acid or ester, ortho ester or amide thereof. Typical leaving groups are the halogens as exemplified by bromine, chlorine and iodine. Alternatively, Z is an anionic residue of an organic acid. Particularly suitable organic acids are those having electron deficient substituents such as exemplified by aryl, aralkyl, cycloalkyl, alkyl, alkenyl and alkynyl sulfonic acids and substituted benzoic and phosphonic acids. Presently preferred are those leaving groups wherein Z represents a group of the formula: ##STR30## wherein R 2 is alkyl, cycloalkyl, alkenyl, alkynyl, aryl or aralkyl. Among such leaving groups, those in which R 2 is alkyl, aryl or aralkyl are especially advantageous, such as methanesulfonyloxy, benzenesulfonyloxy and p-toluenesulfonyloxy.
Groups represented by Z which can be converted to leaving groups are exemplified by hydroxy and by protected hydroxy groups such as acetoxy, benzoyloxy, trialkylsiloxy (e.g. trimethylsiloxy and triethylsiloxy) and dihydropyranyloxy. In some instances, the group represented by Z may itself be a leaving group which can be converted into a different leaving group at a subsequent stage of the process. All such variations are comprehended by Z in its broadest representation.
The organometallic reagents of formula I are conveniently prepared by conventional methods for preparing Grignard reagents. The appropriate aryl halide of the formula:
Ar--X
is dissolved in an anhydrous, aprotic medium such as an ether, for example, tetrahydrofuran, diethyl ether and the like, or mixtures thereof, and added to magnesium metal. Preparative methods analogous to those described in U.S. Pat. No. 3,959,364 can be utilized. For example, 2-bromo-6-methoxynaphthalene is dissolved in an ether such as tetrahydrofuran and the resulting solution added slowly to magnesium to form the magnesium Grignard of 2-bromo-6-methoxynaphthalene. The other divalent metallic derivatives, i.e. of cadmium, copper(II), manganese and zinc, are prepared from the magnesium Grignard of the aryl halide, Ar-X, by conventional exchange procedures, such as have been described in U.S. Pat. Nos. 3,658,858 and 3,975,432. Typically, the magnesium Grignard of the aryl halide is contacted with a halide of the metal to be exchanged in a suitable solvent, such as a hydrocarbon solvent, at elevated temperatures. Whether the compound of the formula ArMX or (Ar) 2 M is formed depends on the amount of metal halide employed in the reaction. The compound of the formula ArMX is primarily formed when one molar equivalent of the metal halide is employed, and the compound of the formula (Ar) 2 M primarily is formed when one-half molar equivalent of the metal halide is employed. For example, the contacting of one molar equivalent of 2-bromo-6-methoxynaphthalene with one-half molar equivalent of zinc chloride in benzene yields a solution of di-(6-methoxy-2-naphthyl)zinc. When one molar equivalent of zinc chloride is employed, a solution of (6-methoxy-2-naphthyl)zinc chloride is obtained. The organo lithium compounds are prepared directly from the aryl halide by contacting the aryl halide with lithium metal in a manner similar to the preparation of the magnesium Grignard. The copper(I) compound is prepared directly from the lithium derivative by reaction with cuprous bromide in an ether solvent (U.S. Pat. No. 3,658,863).
The substituted acyl halides of formula II are prepared from corresponding acids by α-halogenation of the alkanoic acid by the addition of halide in the presence of a catalytic amount of phosphorus trichloride (Hell-Volhard-Zelinsky reaction) to afford the α-haloalkanoic acid. In the case where Z is halogen, the α-haloalkanoic acid is converted directly to the desired acyl halide by reaction with thionyl chloride, phosgene, phosphorous pentachloride or the like. While other acyl halides, e.g. bromides and iodides, can be utilized, the acyl chlorides are generally satisfactory for subsequent addition to the organometallic reagent.
When Z comprises an ester leaving group such as exemplified by a group of the formula: ##STR31## or another anionic residue of an organic acid, the α-haloalkanoic acid is hydrolyzed to the α-hydroxyalkanoic acid, esterified to form the α-hydroxyalkanoate and treated with an appropriate organic acid halide to form the diester. Subsequent hydrolysis affords the α-substituted alkanoic acid. At this stage, the α-substituent does not hydrolyze since the terminal ester group hydrolyzes much more rapidly than the α-substituent. Then the α-substituted alkanoic acid is treated with a halide such as thionyl chloride, benzenesulfonyl chloride, phosgene, phosphorus trichloride or pentachloride or the like to afford the α-substituted acyl halide, which typically is an α-substituted acyl chloride. That sequence of reactions is illustrated by the addition of bromine to propionic acid in the presence of phosphorus trichloride to afford α-brompropionic acid. The α-bromopropionic acid is hydrolyzed with base such as potassium hydroxide, to form the α-hydroxypropionic acid which is esterified with an alcohol, e.g. ethanol, under acidic conditions to afford ethyl 2-hydroxypropionate (i.e. ethyl α-hydroxypropionate). Contacting of ethyl 2-hydroxypropionate with methanesulfonyl chloride yields ethyl 2-methanesulfonyloxypropionate, which is hydrolyzed with potassium hydroxide to afford 2-methanesulfonyloxypropionic acid. Further reaction of that material with thionyl chloride yields 2-methanesulfonyloxypropionyl chloride, which is subsequently utilized.
The optically active α-substituted acyl halides are prepared by resolution of the racemic α-hydroxyalkanoic acids or esters by conventional methods using optically active amine bases or from available amino acids, for example, such as by methods described in the Journal of the American Chemical Society, 76, 6054 (1954).
When α-arylpropionic acids are to be prepared by the process of this invention, a particularly advantageous starting material is lactic acid (i.e. 2-hydroxypropionic acid). The naturally occurring lactic acid, L-(+) lactic acid, is optically active and as such is a preferred starting material for the stereoselective processes described herein. Alternatively, the ethyl ester of L-(+)lactic acid also is commercially available (Pettibone World Trade, Chicago, Ill. and C.V. Chemie Combinatie, Amsterdam C.A.A , Holland) and is a convenient starting material for the optically active α-substituted propionyl halides utilized in the stereoselective process of this invention. Depending on the number of inversions at the asymmetric carbon atom of the propionic acid group during subsequent steps in the process, as will be described more fully hereinafter, either the (+)-lactic acid or the (-)-lactic acid is the preferred starting material. The (-)-lactic acid can be obtained from the racemic lactic acid by conventional resolution methods or prepared directly from glucose via a method described in Biochemical Prepn., 3, 61 (1953).
The optically active, substituted propionyl halides are prepared from the optically active ester of the appropriate lactic acid enantiomer by treating that enantiomer with an organic acid halide, such as, for example, sulfonic acid halides of the formula: ##STR32## wherein R 2 and X are as defined above, to form the α-substituted propionate. Basic hydrolysis of the ester to the acid, such as with potassium hydroxide in aqueous methanol, and subsequent treatment with a halogenating agent, such as thionyl chloride, yields the optically active α-substituted propionyl halide. Typically, (S) ethyl 2-hydroxypropionate, corresponding to the ethyl ester of L-(+)lactic acid, is treated with methanesulfonyl chloride, in the presence of an organic base, such as triethylamine, and an inert solvent, such as toluene, to afford (S) ethyl 2-methanesulfonyloxypropionate. Basic hydrolysis of that material with potassium hydroxide in aqueous methanol yields (S) 2-methanesulfonyloxypropionic acid, which then is allowed to react with thionyl chloride to afford (S) 2-methanesulfonyloxypropionyl chloride.
In order to form the (R) substituted propionyl chloride, one begins with (R) ethyl 2-hydroxypropionate and proceeds through the above-described process sequence to obtain the (R) 2-substituted propionyl halide such as (R) 2-methanesulfonyloxypropionyl chloride.
The acyl amines represented by formula II when Y is a group of the formula: ##STR33## wherein R' and R" are alkyl or aryl or when taken together with N form a heterocyclic moiety which optionally can contain other hetero atoms, are prepared from the acyl halides and an N,N-disubstituted amine or the parent nitrogen containing heterocycle. For example, 2-methanesulfonyloxypropionyl chloride is contacted with dimethylamine to afford N,N-dimethyl 2-methanesulfonyloxypropionamide. Other disubstituted amines can be utilized as well. The acyl amines derived from heterocyclic amines having substantial acidic character such as the imidazoles, pyrroles, indoles and carbazoles are also considered useful.
The acyl halides can be converted to the symmetrical or mixed acid anhydrides corresponding to the compounds of formula II when Y is acyloxy, by contacting the acyl halide with an appropriate acid. For example, 2-methanesulfonyloxypropionyl chloride is allowed to react with acetic acid to afford the mixed anhydride, acetic 2-methanesulfonyloxypropionic anhydride. Additionally, for example, 2-methanesulfonyloxypropionyl chloride is allowed to react with 2-methanesulfonylotypropionic acid to afford bis(2-methanesulfonyloxypropionic)anhydride, a symmetrical anhydride. Alternatively, the acid precursors of the acyl halides of formula II can be contacted with an appropriate acyl halide to afford the symmetrical or mixed acid anhydrides. For example, 2-methanesulfonyloxypropionic acid is allowed to react with acetyl chloride to afford the mixed anhydride, acetic 2-methanesulfonyloxypropionic anhydride.
The optically active acyl amines and acid anhydrides are prepared conveniently from the optically active acyl halides in the manner described above to yield materials particularly useful in the stereospecific process of this invention.
The compounds represented by formula II also encompass compounds in which Z is a group which can be converted into a suitable leaving group at subsequent stages of the process, i.e. at some point after the compound of formula I has been allowed to react with the compound of formula II. Such groups are, for example, hydroxy, and protected hydroxy groups such as acetoxy, benzoyloxy, dihydropyranyloxy, trialkylsiloxy and the like. Typically, the α-hydroxy substituent of the α-hydroxyalkanoic acid or an ester thereof is protected during the addition of the compound of formula II to the compound of formula I. Subsequently, the protecting group is removed and a suitable leaving group is generated. Typically, (S) 2-hydroxypropionic acid is treated with acetyl chloride in the presence of sulfuric acid to yield (S) 2-acetoxypropionic acid. Subsequent treatment with thionyl chloride affords (S) 2-acetoxypropionyl chloride, a compound of formula II.
The compound of formula I is allowed to react with the compound of formula II to yield a compound of the formula: ##STR34## wherein Ar, R 1 , and Z are as defined above. By employing an optically active acyl halide, acyl amine or acid anhydride of the formula II, the corresponding optically active aryl α-substituted alkyl ketone is obtained. That reaction step proceeds with substantially 100% retention of optical activity. For example, the magnesium Grignard of 2-bromo-6-methoxynaphthalene is contacted with (S) 2-methanesulfonyloxypropionyl chloride in an inert solvent such as tetrahydrofuran to yield (S) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one. The use of the (R) form of the acyl halide produces the (R) form of the ketone, e.g. (R) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one. Reaction conditions for this step of the process are not considered critical. Generally, the reaction is conducted at temperatures below room temperature. For example, the range of -70° C. to 0° C. is suitable. Inert solvents such as the ethers (e.g. tetrahydrofuran) form a convenient medium for conducting the reaction. The solvents may be used alone or as mixtures The ratio of the acyl halide, acyl amine or acid anhydride to the organmetallic compound typically is between 1.0-1.5 equivalents, although greater excesses can be used.
The racemic and optically active ketones of the formula: ##STR35## can be utilized in alternate processes to yield the desired α-arylalkanoic acids Representative process schemes are illustrated below. ##STR36## In Scheme I, Ar, R 1 and Z are as defined above. R 3 and R 4 are alkyl having 1-8 carbon atoms, optionally the same or different, or when taken together, are alkylene having 2-8 carbon atoms.
In Reaction Scheme I, the ketalization step (step A) is conducted under conditions of retention of configuration at the asymmetric carbon atom. Typically, the ketal is formed by contacting the ketone with an ortho ester in the presence of an acid catalyst in an alcoholic solvent. Such a method utilizes trialkyl orthoformates, such as trimethyl orthoformate or triethyl orthoformate in the presence of an acid catalyst such as sulfuric acid, p-toluenesulfonic acid, ferric chloride, ammonium nitrate, ammonium chloride or acidic ion exchange resins such as Amberlyst-15, Nafion H(perfluoronated sulfonate polymer) and acidic montmorillonite clay (e.g. Girdler® catalyst K-10, Girdler Chemicals Inc., Louisville, Ky.). Typically, (S) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one is contacted with trimethyl orthoformate in the presence of sulfuric acid to yield (S) 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)prop-2-yl methanesulfonate.
Cyclic ketals are formed by using glycols and other polyhydric alcohols such as ethylene glycol, trimethylene glycol, dimethylpropylene diol and the like in the presence of an acid catalyst. The water which forms is removed by azeotropic distillation. Other useful ketalization agents are trimethylsilyl trifluoromethanesulfonate with an alkoxysilane [Tetrahedron Letters, 21, 1357-8 (1980)], 2,2-dimethoxypropane and dimethylsulfite. The ketalization agents can be used in amounts of about 1-50 molar equivalents per molar equivalent of ketone. When the orthoformates are utilized, a range of 2.0-5.0 equivalents is satisfactory. Usually about 0.5-20 percent on a molar basis of acid catalyst is utilized. Inert solvents such as alcohols, benzene, toluene and the like are utilized When the cyclic ketals are formed from the polyhydric alcohols, a solvent such as toluene or benzene typically is used to allow azeotropic distillation of the water formed. While temperatures are not critical, temperatures in the range of 0° C. to 150° C. are typical depending on the solvent and the ketal.
When trimethyl orthoformate is utilized as the ketalization agent, the addition of an inert co-solvent such as toluene or methylene chloride appears to solubilize the ketone and lead to reduced usage of trimethyl orthoformate A temperature range of 35° C. to 80° C. is presently preferred and about 30 percent on a molar basis of oleum gives particularly satisfactory results. Reaction times of hours to days are considered typical depending on the nature of the solvent and the temperature and the amount of ketalizing agent used.
The rearrangement step (step B) can be conducted by a variety of methods depending to some extent on the nature of the leaving group Z.
When Z is halogen, the rearrangement is conveniently conducted in an inert solvent in the presence of catalyst such as a Lewis acid (see for example European Patent Office Application No 81200210.3, filed Feb. 23, 1981, bearing publication No. 0034871, published Sep. 2, 1981). Representative catalysts are the organic salts, such as acetate, propionate, benzoate, trifluoromethanesulfonate, methanesulfonate, and the like, and the inorganic salts such as chloride, bromide, iodide, sulfate and the like of copper, magnesium, calcium, zinc, cadmium, barium, mercury, tin, antimony, bismuth, manganese, iron, cobalt, nickel and palladium. The metal halides such as zinc chloride, cobalt chloride, zinc bromide, stannous chloride, ferrous chloride, ferric chloride, nickel bromide, cadmium chloride, magnesium chloride, mercurous chloride, mercuric chloride, antimony chloride, barium chloride, calcium chloride, cuprous chloride, cupric chloride, manganese chloride, stannic chloride, bismuth chloride and palladium trichloride are considered particularly useful. The rearrangement is conducted in a suitable solvent such as the aliphatic halohydrocarbons, aliphatic cyclic hydrocarbons, lower alcohols, aliphatic acids and esters thereof, aromatic hydrocarbons and haloaromatic hydrocarbons. Representative examples are dichloromethane, trichloromethane, chlorobenzene, toluene, methylene chloride, methanol, trimethyl orthoformate and mixtures thereof. The rearrangement is conducted in the temperature range from about 0° C. to the reflux temperature of the solvent, with due consideration given to the temperature stability of the ketal and the resulting acid or esters thereof. Reaction times are not critical and vary with the nature of the ketal and the catalyst and the reaction temperature. Times ranging from about 0.5 hours to 160 hours are considered representative. Other particulars of the rearrangement process can be found in the above-referenced European Patent Application, Publication No. 0034871, which is incorporated herein by reference.
An alternative rearrangement process when Z is halogen has been described in British Application No. 8005752, filed Feb. 20, 1980, bearing publication No. 2,042,543, published Sep. 24, 1980, and which is incorporated herein by reference. That process utilizes the silver (I) salts of organic or inorganic anions as catalysts for the rearrangement step in an acidic, alcoholic medium. The acid typically is selected from the Lewis acids, boron trifluoride, fluoroboric acid, methanesulfonic acid, sulfuric acid, the complexes BF 3 .2CH 3 COOH, HBF 4 .Et 2 O (etherated fluoroboric acid), BF 3 .Et 2 O (boron trifluoride etherate) and BF 3 .2CH 3 OH. The silver salts are the silver (I) salts of organic and/or inorganic anions, mixtures thereof, and silver oxide. Representative silver salts are silver acetate, AgSbF 6 (silver hexafluoroantimoniate), AgClO 4 (silver perchlorate), AgCF 3 SO 3 (silver trifluoromethane sulfonate), AgBF 4 (silver tetrafluoroborate), silver nitrate, silver carbonate, silver sulfate and silver oxide. The rearrangement is conducted in a protic or dipolar, aprotic solvent, such as provided by an alcoholic medium, including the alkanols (e.g. methanol, ethanol), and cycloalkanols, and as provided by the orthoformates, acetone dimethylacetal or the BF 3 .2CH 3 OH complex.
When Z comprises an ester leaving group of the formula: ##STR37## or another anionic residue of an organic acid, the ketal formed in step A is solvolyzed according to step B to the rearranged α-arylalkanoic acid or an ester, ortho ester or amide thereof, depending on the solvolysis conditions. The solvolysis is conducted under either basic, neutral or acidic conditions. Reaction times, temperatures and material ratios during the solvolysis step are not considered critical. Typically, temperatures in the range between 0° C. and 200° C. and times ranging between 1-100 hours are satisfactory. Temperatures of greater than 50° C. appear to accelerate the rearrangement. Typically, the solvolysis is effected by maintaining the ketal in contact with a protic or dipolar, aprotic solvent for a time sufficient to form the α-arylalkanoic acid or the ester, ortho ester or amide thereof. Protic solvents comprehended include water, alcohols, ammonia, amides, N-alkylamides, carboxylic acids and mixtures thereof.
Representative alcohols include primary, secondary and tertiary alcohols and polyhydric alcohols. They include alkanols, alkenols, cyclic alkanols, aromatic alcohols, glycols, and the like. Examples of the alkanols comprehended are methanol, ethanol, butanol, pentanol, hexanol, heptanol, octanol, and the branched chain isomers thereof. Examples of the alkenols are allyl alcohol, 2-buten-1-ol and the like. Cyclic alkanols are exemplified by cyclopropanol, cyclobutanol, cyclohexanol and the like. Examples of aromatic alcohols are phenol, α-naphthol, β-naphthol, p-cresol and the like. Representative amides are formamide, acetamide, propionamide, benzamide and the like. Typical of the N-alkyl amides are N-methylformamide and N-ethylformamide. Carboxylic acids are alkanoic acids such as formic acid, acetic acid, propionic acid, n-butyric acid and the branched chain isomers thereof; alkenoic acids, such as acrylic acid, maleic acid and fumaric acid and the like; aryl acids such as benzoic acid, and the like, and diacids such as phthalic acid, isophthalic acid, malonic acid, succinic acid, glutaric acid and the like.
Dipolar, aprotic solvents are typified by dimethylsulfide, acetone, dioxane, 1,2-dimethoxyethane, carbon disulfide, dialkylamides such as dimethylacetamide and dimethylformamide, nitrobenzene, nitromethane, acetonitrile and the like and mixtures thereof.
The rate of the rearrangement reaction appears to be enhanced by the presence of salts of organic or inorganic anions. For example, the addition of sodium acetate or sodium bicarbonate to the reaction mixture facilitates the reaction. Additionally, it is sometimes desirable to buffer the solvent medium to prevent hydrolysis of the ketal prior to occurance of the rearrangement. Typical buffering salts include the calcium, sodium, potassium and lithium salts of carbonate, bicarbonate, anions of organic acids and phosphates.
Depending on the nature of the protic or dipolar aprotic solvent medium, the α-arylalkanoic acid may not be directly formed. Instead, the ester, ortho ester or amide of the α-arylalkanoic acid may be formed. For example, if the solvent medium contains water, an ester of the α-arylalkanoic acid typically is formed wherein the ester group is derived from the ketal functionality or from the solvent. Mixed esters can be formed. Under anhydrous alcoholic conditions, ortho esters of the α-arylalkanoic acid can be formed wherein the ester groups may be derived from the ketal functionality or from the solvent and may be mixed. Likewise, when an amine is present in the solvent medium, formation of an amide of the α-arylalkanoic acid can be expected. Those compounds typically are not isolated but are hydrolyzed directly to the desired α-arylalkanoic acid.
Depending on the reaction conditions, hydrolysis of an ester, ortho ester or amide formed may be effected concomitantly or sequentially by standard methods. For example, when the protic solvent medium comprises acetic acid and sodium acetate and the ester substrate comprises 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)prop-2-yl methanesulfonate, there is afforded the compound, methyl 2-(6-methoxy-2-naphthyl)propionate. The methyl ester is then hydrolyzed to the corresponding acid by contact with base. Alternatively, the α-arylalkanoic acid can be obtained by concomitant hydrolysis by maintaining the ester substrate in contact with a methanol-water solution containing sodium bicarbonate. Typically, 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)prop-2-yl methanesulfonate is maintained in contact with a methanol-water solution containing sodium bicarbonate to afford 2-(6-methoxy-2-naphthyl)propionic acid.
When the stereosolective process described herein is utilized to produce the optically active esters of the α-arylalkanoic acids, it has been determined that the presence of excess base during the solvolytic rearrangement step can racemize the optically active ester so produced. Accordingly, it is presently desirable to minimize the amount of base which is in contact with the optically active ester. That can be accomplished by conducting the solvolysis under buffered acidic conditions or in the presence of an insoluble base, i.e. a base which is insoluble in the solvent phase containing the optically active ester, or in a weakly basic media. For example, when the solvolysis is conducted in methanol, the use of calcium carbonate or resin bases as the insoluble base gives satisfactory results. For example, when (S) 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)prop-2-yl methanesulfonate is maintained in contact with an aqueous methanol solution in which calcium carbonate is stirred as an insoluble base, (S) methyl 2-(6-methoxy-2-naphthyl)-propionate is obtained in greater than 95 percent optical purity. The methyl ester then is converted to (S) 2-(6-methoxy-2-naphthyl)propionic acid by acid catalysis or saponification, where such saponification is conducted in an aprotic solvent such as acetone.
The problem of isomerization in the presence of excess base appears to be due in part to the relative slowness of the rearrangement step. During solvolysis, at any one time only a small amount of sulfonic acid, e.g. methanesulfonic acid, is being formed. If an insoluble, substantially insoluble, or weak base is utilized, only a very low concentration of hydroxyl ions are present. The low concentration is sufficient to neutralize the acid formed but is insufficient to isomerize the optically active ester formed.
Alternatively, the rearrangement step (step B) can also be effected by contacting the ketal formed in step A with an agent having affinity for oxygen. Under such conditions, the ester of the α-arylalkanoic acid is produced.
The agents having an affinity for oxygen are those compounds having the ability to coordinate to accept a lone electron pair of an oxygen atom. Representative examples are iodotrialkylsilanes, such as iodotrimethylsilane, iodotriethylsilane and the like, the trialkylsilyl perfluoroalkylsulfonates such as trimethylsilyl trifluoromethanesulfonate, trimethylsilyl pentafluoroethanesulfonate and the like, and Lewis acids such as aluminum chloride, aluminum bromide, zinc chloride, stannous chloride, stannic chloride, titanium chloride, boron fluoride, ferric chloride, ferrous chloride and the other Lewis acids described previously. The agents having affinity for oxygen can be used alone or as mixtures.
The amount of the agent having an affinity for oxygen used depends to some extent on the type of the ketal being rearranged and/or on the type of the agent Generally, it is used in an amount of about 0.1 to 5.0 moles per mole of the ketal formed in step A. A range of 1.0-2.0 moles is presently preferred.
The treatment of the ketal formed in step A with the agent having affinity for oxygen can be carried out in the absence of solvent. However, the process is conveniently carried out in a solvent, especially an aprotic solvent. For example, where a Lewis acid or an iodotrialkylsilane is used, halogenated hydrocarbons such as methylene chloride, chloroform and 1,2-dichloroethane are advantageous. When the trialkylsilyl perfluoroalkanesulfonates are used, the halogenated hydrocarbons, acetonitrile and orthoformates are presently preferred as solvents.
Reaction conditions can vary widely, although a temperature range of about -40° C. to about 150° C. is satisfactory. A range of about -20° C. to about 100° C., and especially about -10° C. to about 90° C., is presently preferred.
When the agent having affinity for oxygen is a Lewis acid, the product produced in step B may sometimes form a complex with the agent. In this case, the product may be isolated by adding water to the reaction mixture to decompose the complex. The desired product is then isolated by conventional methods, such as extraction, chromatography, distillation and crystallization.
When Z is a group which is convertible to a suitable leaving group, the conversion of Z can take place either before step A or thereafter, but before step B. For example, when the magnesium Grignard of 2-bromo-6-methoxynaphthalene is contacted with (S) 2-trimethylsiloxypropionyl chloride, (S) 1-(6-methoxy-2-naphthyl)-2-trimethylsiloxypropan-1-one is obtained. Regeneration of the hydroxyl group by hydrolysis affords (S) 2-hydroxy-1-(6-methoxy-2-naphthyl)propan-1-one. Further reaction with methanesulfonyl chloride then affords (S) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxy propan-1-one, which is processed according to step A. Alternatively, the ketone can first be ketalized according to step A and the regeneration of the hydroxyl group and the formation of the sulfonate ester can occur subsequently but prior to step B.
When it is desired to practice the stereoselective process described herein, the particular stereoismer of the material described by the formula: ##STR38## is produced to provide the desired optically active stereoisomer of the formula: ##STR39## or an ester, ortho ester or amide thereof, wherein Ar, R 1 and Z are as defined above. In Reaction Scheme I, the ketalization step A proceeds under conditions of retention of configuration and the rearrangement step B proceeds under conditions of inversion of configuration at the asymmetric carbon atom. Accordingly, for example, when it is desired to produce (S) (6-methoxy-2-naphthyl)propionic acid, the (S) form of ethyl lactate is utilized to produce (S) 2-methanesulfonyloxypropionyl chloride in the manner described previously. Utilization of the (S)-form of that reagent with the magnesium Grignard of 6-methoxy-2-bromonaphthalene affords (S) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one. Ketalization with retention of configuration with trimethyl orthoformate in the presence of a catalytic amount of sulfuric acid yields (S) 1,1-dimethoxy-1-(6-methoxy-2-naphthylprop-2-yl methanesulfonate. Rearrangement of that material with sodium acetate and acetic acid in ethanol proceeds with inversion of configuration at the asymmetric carbon atom and affords (S) ethyl 2-(6-methoxy-2-naphthyl)propionate. That material is then hydrolyzed to the corresponding (S) acid.
Because the "sequence rule," when assigning an "R" or "S" configuration, depends on the nature of the groups attached to the asymmetric carbon atom, the absolute configuration of the starting and ending material in the rearrangement step is each "S" in the example given, even though there is inversion of configuration at the asymmetric carbon atom. The migration of the 6-methoxy-2-naphthyl group to the asymmetric carbon atom with inversion of configuration at that carbon atom dictates that notation.
When Z is a group of the formula: ##STR40## wherein R 2 is alkyl, cycloalkyl, alkenyl, alkynyl, aryl or aralkyl, or another anionic residue of an organic acid, step A and step B can be conveniently combined by conducting the ketalization (Step A) at elevated temperatures to effect rearrangement (step B) to the ester of the α-arylalkanoic acid. That combined ketalization-rearrangement typically is conducted at elevated temperatures in excess of 80° C. and at appropriate pressures to attain those elevated temperatures with the solvents being utilized. Typically, (S) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one is contacted with trimethyl orthoformate in the presence of 98 percent sulfuric acid in methanol and heated under 50 psi to above 80° C., to afford (S) methyl 2-(6-methoxy-2-naphthyl)propionate. Reaction times, ranging from hours to days, can vary depending on the amount of orthoformate used and the temperature at which the process is conducted. Higher temperatures may require correspondingly higher operating pressures depending on the solvents utilized.
An alternative scheme for the preparation of the α-arylalkanoic acids and esters proceeds with two inversions at the asymmetric carbon atom and is represented by the following reaction sequence: ##STR41## In Scheme II Ar, R 1 and Z are as defined above with the understanding that Z prior to step C may be the same or different than Z after step D. R 5 and R 6 are alkyl, aryl or aralkyl, optionally the same or different, or, when taken together, are alkylene having 2-8 carbon atoms. Scheme II differs from Scheme I in that the ketalization step C takes place under conditions which result in the formation of the α-hydroxy ketal with inversion of configuration at the asymmetric carbon atom. Ketalization with alkali metal alkoxides, aralkyloxides or aryloxides in an alcoholic medium yields the α-hydroxy ketals in which inversion at the asymmetric carbon atom has occurred. Representative alkali metals are sodium, potassium and lithium. The alkoxides contain 1-8 carbon atoms and are exemplified by methoxide, ethoxide and the like. Aralkyloxides and aryloxides are exemplified by benzyloxide, phenoxide and the like. Alternatively, the cyclic ketals can be formed with the polyhydric alcohols described previously in Scheme I in the presence of a catalytic amount of the alkali metal alkoxides to afford the α-hydroxy cyclic ketals in which inversion at the asymmetric carbon atom has occurred.
Regeneration of a leaving group Z in step D typically is effected by contacting the α-hydroxy ketal with an organic acid halide, such as an alkyl, alkenyl, alkynyl, cycloalkyl, aryl or aralkyl sulfonyl halide. That step occurs with retention of configuration. Rearrangement of the ester in step E takes place with inversion of configuration utilizing the methods described previously with respect to Scheme I.
Since Scheme II involves two inversions at the asymmetric carbon atom, (i.e. one inversion during the rearrangement step) the appropriate stereoisomer of the compound of the formula: ##STR42## wherein Ar, R 1 , and Z are as defined above, must be chosen to provide the desired optically active stereoisomer of the α-arylalkanoic acid being produced. For example, to produce (S) 2-(6-methoxy-2-naphthyl)-propionic acid or an ester, ortho ester or amide thereof according to the procedure of Scheme II, it is necessary to begin with (R) ethyl lactate. That material is converted to (R) 2-methanesulfonyloxypropionyl chloride in the manner described herein and allowed to react with the magnesium Grignard of 2-bromo-6-methoxynaphthalene to yield (R) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one. Ketalization in step C with sodium methoxide in methanol then affords, with inversion of configuration, (S) 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)propan-2-ol. Ester formation in step D occurs by contacting the (S)-ketal above with methanesulfonyl chloride to afford (S) 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)prop-2-yl methanesulfonate, which is rearranged with inversion by contacting with sodium acetate and acetic acid to afford (S) methyl 2-(6-methoxy-2-naphthyl)propionate. The foregoing example is again illustrative of the peculiarities of the "sequence rule" of nomenclature, which, when utilized to assign absolute configurations to asymmetric carbon atoms, can result in an (S)-compound being converted to another (S)-compound even though inversion at the asymmetric carbon atom has occurred. That apparent inconsistency is in reality no inconsistency at all because the assignment of the "R" or "S" configuration depends on the nature of the groups attached to the asymmetric carbon atom.
The foregoing illustration is representative of the situation wherein the leaving group Z prior to step C is the same as the leaving group Z prior to step E. The leaving group Z in each instance need not be identical. For example, Z prior to step C can be a halogen, such as bromo and chloro, which is eliminated in the formation of the α-hydroxyketal Then, the α-hydroxyketal can be contacted with methanesulfonylchloride to yield the ketal wherein the leaving group Z is methanesulfonyloxy.
The ketones of the formula III wherein Z is halogen can also be prepared from compounds prepared from (R), (S) or (RS) lactic acid or the esters thereof. In this aspect of the invention, the compounds of formula III wherein Z is a group of the formula: ##STR43## wherein R 2 is as previously defined are contacted with an alkali metal halide to yield the optically active or racemic compound of formula III in which Z is halogen. Typically, lithium bromide or lithium chloride is used, or a phase transfer catalyst is employed with potassium bromide in a non-polar organic solvent such as toluene. In certain solvents the reaction proceeds with racemization at the asymmetric carbon atom and as such is not universally suitable for the preparation of the optically active α-halo ketones. For example, (R) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one is contacted with lithium bromide in dimethylformamide to afford substantially all (RS) 2-bromo-1-(6-methoxy-2-naphthyl)propan-1-one. That material is suitable for use in Reaction Scheme I to produce racemic 2-(6-methoxy-2-naphthyl)propionic acid. Similarly, (S) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxy-propan-1-one is contacted with lithium bromide to afford (RS) 2-bromo-1-(6-methoxy-2-naphthyl)propan-1-one, which is suitable for use in Reaction Scheme II to produce racemic 2-(6-methoxy-2-naphthyl)propionic acid.
In still another alternate process, the compounds of formula III can be processed according to the following Scheme III: ##STR44## In Scheme III, Ar, R 1 and Z are as defined above. In step F the aryl alkyl ketone is reduced to the corresponding alcohol by catalytic hydrogenation or with metal hydrides. Catalytic hydrogenation is conveniently effected with hydrogen in the presence of a catalyst such as platinum, palladium, Raney nickel, copper chromite and the like. Convenient metal hydrides are exemplified by the borohydrides such as sodium borohydride and the aluminum hydrides such as lithium aluminum hydride. Times and temperatures will vary with the reducing agent utilized and are conventional. Typically, hydrogenation can be conducted at a temperature in a range from about 15° to 200° C. and at pressures of one atmosphere or more. The metal hydride reductions typically are conducted in ethers, dilute aqueous and/or alcoholic acids, water, alcoholic solvents, and mixtures thereof. Sodium borohydride is an especially convenient reducing agent since it rapidly reduces the ketone moiety while being relatively inert to other substituents in the substrate.
The alcohol formed in step F is rearranged in step G to the corresponding aldehyde by the methods of rearrangement described previously for Schemes I and II. The aldehyde is oxidized by conventional methods to the corresponding acid in step H. A typical oxidation is the chromic acid oxidation described in U.S. Pat. No. 3,637,767. Other oxidation agents, such as sodium chlorite, may be used as well.
Representative of Scheme III is the reaction of 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one with sodium borohydride in methanol to yield 1-hydroxy-1-(6-methoxy-2-naphthyl)prop-2-yl methanesulfonate. Treating that material with sodium acetate in acetic acid affords 2-(6-methoxy-2-naphthyl)propanal, which is oxidized with sodium chlorite to 2-(6-methoxy-2-naphthyl)propionic acid. By employing the optically active (S) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one there is obtained, following the same sequential steps, (S) 2-(6-methoxy-2-naphthyl)propionic acid.
Because application of the "sequence rule" of nomenclature depends on the nature of the groups attached to the asymmetric carbon atom in assigning an (R) or (S) configuration to that carbon atom, it is not possible to state generally that an optically active substituted acyl halide, acyl amine or acid anhydride denoted as (S) will produce an (S) or an (R) product. It can be seen from what has been described previously, that depending on the number of inversions occuring at the asymmetric carbon atom, one may want to begin with an (S) or an (R) substituted acyl halide, acyl amine or acid anhydride in the practice of this invention. However, in view of this disclosure it is considered to be well within the skill of those in the art to which this invention pertains to choose the appropriate optically active starting material to arrive at the desired optically active product.
The present invention is also directed to an optically active stereoisomer of a compound of the formula ##STR45## wherein R 1 is alkyl or cycloalkyl and Z is a leaving group, in the substantial absence of any other stereoisomer of that compound. In the context of this invention, the single stereoisomer of the above-described compounds of formula IV can correspond to 100% optical purity. However, due to the nature of chemical reactions, a certain amount of another stereoisomer of the compound may be present at the conclusion of the stereoselective preparation due to a small amount of isomerization to the undesired stereoisomer. Accordingly, for the purposes of this invention, the desired optically active stereoisomer is considered to exist in the substantial absence of any other stereoisomers of the compound if the desired optically active stereoisomer has an optical purity of 90% or more.
In the majority of instances, only a single center of asymmetry is present in the compounds of formula IV and only two stereoisomers, i.e., the enantiomers, will be present. In those instances, the optically active enantiomer of a compound of formula IV will be present in the substantial absence of the other enantiomer In another instance, more than one center of asymmetry may exist in the compounds of formula IV. In that instance, the optically active diastereomer will be present in the substantial absence of any other diastereomer of a compound of formula IV.
For example, when Z is methanesulfonyloxy and R 1 is methyl, the compound of formula IV will consist of two optically active enantiomers, i.e.,
(R) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one; and
(S) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one.
In this example, an aspect of this invention (useful in the process of Scheme I outlined above) is a material containing
(S) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one in the substantial absence of
(R) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one.
Another aspect of this invention (useful in the process of Scheme II outlined above) is a material containing
(R) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one in the substantial absence of
(S) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one
However, when Z is d-10-camphorsulfonyloxy and R 1 is methyl, the compound of formula IV consists of two diastereomers which are not mirror images of each other (i.e., not enantiomers). In those instances, the composition of the invention consists of one diastereomer in the substantial absence of the other diastereomer.
While the stereoselective process of this invention is primarily utilized to produce an optically active product, which is present as a single stereoisomer in the substantial absence of any other stereoisomer of the product, thus eliminating subsequent resolution steps, the production of a product enriched in or having a major amount of the single stereoisomer as compared to any other stereoisomer of the product is also useful since the economics of any necessary resolution are improved over the case where a racemic mixture is being resolved.
As described previously, the compounds of formula IV are prepared by reacting an optically active substituted acyl halide, acyl amine or acid anhydride with the Grignard of 2-bromo-6-methoxynaphthalene in an ethereal solvent such as tetrahydrofuran, ethyl ether and the like or mixtures thereof. The preparation of the optically active acyl halides, acyl amines and acid anhydrides has been described previously herein.
The present invention is also directed to an optically active stereoisomer of a compound of the formula: ##STR46## wherein R 1 is alkyl having 1-8 carbon atoms, R 3 and R 4 are alkyl having 1-8 carbon atoms, optionally the same or different, or when taken together, are alkylene having 2-8 carbon atoms, and Z is halogen, hydroxy, acetoxy, benzoyloxy, dihydropyranyloxy, trialkylsiloxy or a group of the formula: ##STR47## wherein R 2 is alkyl, cycloalkyl, alkenyl, alkynyl, aryl or aralkyl, but not d-10-camphoryl when R 3 and R 4 are methyl, in the substantial absence of any other stereoisomer of that compound. When only one center of asymmetry is present in a compound of formula V, the composition consists of a single enantiomer of that compound in the substantial absence of the other enantiomer. When two or more centers of asymmetry are present in a compound of formula V, the composition consists of a single diastereomer in the substantial absence of any other diastereomer of that compound. For the purposes of this invention, the desired optically active stereoisomer is considered to exist in the substantial absence of any other stereoisomers of the compound if the desired optically active stereoisomer has an optical purity of 90% or more.
Any single enantiomer or diastereomer can be utilized in the stereoselective process described herein depending on whether a single or multiple inversion takes place during the sequence of reaction steps to obtain the desired 2-(6-methoxy-2-naphthyl)alkanoic acid.
The invention is further exemplified by the embodiments described in the following illustrative and nonlimiting examples.
EXAMPLE 1
120 Grams of (S) ethyl lactate and 120 grams of triethylamine are dissolved in 500 ml. of toluene, with stirring, and the solution is cooled to about 10-15° C. Then, 120 grams of methanesulfonyl chloride are added slowly over a 1-1/2 hour period while maintaining the temperature in the range of 10-15° C. The formation of triethylamine hydrochloride as a precipitate is observed. The solution then is allowed to warm to about 20° C. and is poured into water. The aqueous and organic layers are separated and the organic layer is dried over magnesium sulfate and evaporated. The residue remaining is distilled at about 110° C. under 2 mm. Hg to afford 161 grams of (S) ethyl 2-methanesulfonyloxypropionate displaying an optical rotation of [α] 25 D =-44°. That compound displays a characteristic NMR spectra of δ=1.28 (triplet, J=2.2), 1.57 (doublet, J=2.3), 3.12, 4.23 (quartet, J=2.2 ), 5.12 (quartet, J=2.3).
EXAMPLE 2
A solution of 75 grams of (S) ethyl 2-methanesulfonyloxypropionate in 250 ml. of methanol and 100 ml. of water is cooled to about 15° C. A 40% aqueous sodium hydroxide solution is slowly added to the above solution to maintain the pH at about 10.5. The reaction proceeds with rapid fall of pH and continued additions of the sodium hydroxide solution are made until the pH falls very slowly or is substantially constant. Then, concentrated hydrochloric acid is added until a pH of 1.9 is obtained. The methanol is removed under reduced pressure and the aqueous layer remaining is extracted with methylene chloride. The organic extract is evaporated to yield, as an oil, 49 grams of (S) 2-methanesulfonyloxypropionic acid, displaying an optical rotation of about [α] 25 D =-53.3°.
EXAMPLE 3
84.85 Grams of (S) ethyl 2-methanesulfonyloxypropionate is dissolved in a solution of 180 ml. of methanol and 80 ml of water, and the resultant solution is cooled to below -15° C. Then an aqueous 35% sodium hydroxide solution is added slowly to maintain the pH at less than or equal to 10.5 and the addition is continued until the pH remains substantially constant. Concentrated hydrochloric acid is added to acidify the solution to a pH of about 1.8 and the methanol is evaporated under reduced pressure. The aqueous layer is extracted with ethyl acetate several times, and the organic extracts are dried over magnesium sulfate. Evaporation of the organic extract to dryness affords 51 grams of (S) 2-methanesulfonyloxypropionic acid, exhibiting an optical rotation in methylenechloride of [α] 25 D =-54°. That compound is crystallized from toluene and exhibits a melting point of 72°-75° C. and a characteristic NMR spectra of δ=1.62 (doublet, J=2.3), 3.09, 5.11 (quartet, J=2.3), 10.
EXAMPLE 4
A mixture containing 40 grams of (S) 2-methanesulfonyloxypropionic acid, 32 grams of thionyl chloride and one drop of dimethylformamide is heated to about 50° C., at which temperature gas evolution is observed. The mixture is slowly heated to about 70° C. and maintained at that temperature for about 1 hour. Distillation at 110° C. under 1.5 mm Hg affords 31.2 grams of (S) 2-methanesulfonyloxypropionyl chloride, exhibiting an optical rotation in methylene chloride of [α] 25 D =-36.9°. That compound exhibits a characteristic NMR spectra of δ=1.68 (doublet, J=2.3), 3.15, 5.25 (quartet, J=2.3).
EXAMPLE 5
By substituting an equivalent quantity of thionyl bromide in Example 4 and otherwise following the procedure of that Example there is obtained (S) 2-methanesulfonyloxypropionyl bromide.
EXAMPLE 6
By substituting an equivalent quantity of p-toluenesulfonyl chloride in Example 1 and following the procedure of that Example with heating at 60° C. for 8 hours, and subsequently proceeding according to the manner described in Examples 3 and 4, there is obtained (S) 2-p-toluenesulfonyloxypropionyl chloride. That compound exhibits an [α] 25 D =-32° in chloroform and a characteristic NMR spectra of δ=1.18 (triplet, J=2.2), 1.48 (doublet, J=2), 2.45, 4.13 (quartet, J=2.2), 4.96 (quartet, J=2), 7.28-8.03 (multiplet).
EXAMPLE 7
By substituting an equivalent quantity of benzenesulfonyl chloride for the methanesulfonyl chloride of Example 1, and proceeding according to that Example with heating at 30°-40° C. for 5-6 hours and subsequently following the procedure of Examples 3 and 4, there is obtained (S) 2-benzenesulfonyloxypropionyl chloride.
EXAMPLE 8
By substituting an equivalent quantity of (R) ethyl lactate in the procedure of Example 1 and otherwise following that procedure and those described in Examples 2 and 4, there is obtained (R) 2-methanesulfonyloxypropionyl chloride.
EXAMPLE 9
10 Grams of 2-bromo-6-methoxynaphthalene dissolved in 40 ml. of tetrahydrofuran are slowly added to 3.6 grams of magnesium metal at the refluxing temperature of tetrahydrofuran (about 60-62° C.) After the addition is completed, the mixture is stirred at reflux for about 1 hour and the excess magnesium is removed by filtration to afford the Grignard solution [(6-methoxy-2-naphthyl)-magnesium bromide in tetrahydrofuran].
EXAMPLE 10
The solution of (6-methoxy-2-naphthyl)magnesium bromide prepared in Example 9 is slowly added to 8 grams of (S) 2-methanesulfonyloxypropionyl chloride dissolved in 40 ml of tetrahydrofuran which has been cooled to -40° C., while keeping the temperature of the reaction mixture at about -40° C. The mixture is stirred for an additional hour at that temperature and poured into 200 ml of 5% aqueous hydrochloric acid. 100 Ml. of ethyl ether is added to the reaction mixture. The precipitate is recovered by filtration and washed with 30 ml. of ice cold ethyl ether to yield 6.46 grams of (S) 2-methanesulfonyloxy-1-(6-methoxy-2-naphthyl)propan-1-one, melting at 149-151° C. and displaying an optical rotation in chloroform of [α] 25 D =-33°. That compound displays a characteristic NMR spectra in deutorochloroform of δ=1.65 (doublet, J=2.1), 3.10, 3.9, 6.17 (quartet, J=2.1), 8.55-7.10 (multiplet).
EXAMPLE 11
Substitution of an equivalent quantity of (S) 2-p-toluenesulfonyloxypropionyl chloride in the procedure of Example 10 and conducting the coupling at -78° C. affords (S) 1-(6-methoxy-2-naphthyl)-2-p-toluenesulfonyloxypropan-1-one. That compound exhibits a melting point of about 117-119° C., an [α] 25 D =+24.2° in chloroform and a characteristic NMR spectra of δ=1.67 (doublet, J=2.2), 2.37, 3.98, 5.92 (quartet, J=2.2), 7.14-8.44 (multiplet).
EXAMPLE 12
Substitution of an equivalent quantity of (S) 2-benzenesulfonyloxypropionyl chloride in the procedure of Example 10 affords (S) 2-benzenesulfonyloxy-1-(6-methoxy-2-naphthyl)propan-1-one.
EXAMPLE 13
Substitution of an equivalent quantity of (R) 2methanesulfonyloxypropionyl chloride in the procedure of Example 10 affords (R) 2-methanesulfonyloxy-1-(6-methoxy-2-naphthyl)propan-1-one.
EXAMPLE 14
Substitution of an equivalent quantity of (R) 2-p-toluenesulfonyloxypropionyl chloride in the procedure of Example 10 affords (R) 1-(6-methoxy-2-naphthyl)-2-p-toluenesulfonyloxypropan- 1-one.
EXAMPLE 15
Substitution of an equivalent quantity of (R) 2-benzenesulfonyloxypropionyl chloride in the procedure of Example 10 affords (R) 2-benzenesulfonyloxy-1-(6-methoxy-2-naphthyl)propan-1-one.
EXAMPLE 16
A slurry of 4.6 grams of (S) 2-methanesulfonyloxy-1-(6-methoxy-2-naphthyl)propan-1-one in 50 ml. of methanol is treated with 50 grams of trimethyl orthoformate and 2 g of concentrated sulfuric acid. The mixture is heated to about 55° C. and maintained at that temperature for about 15 hours. Then the mixture is cooled and poured into aqueous sodium bicarbonate and extracted with 120 ml. of ethyl ether. The organic layer is separated and dried over magnesium sulfate and filtered. Evaporation of the ether under reduced pressure affords 4.8 grams of (S) 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)prop-2-yl methanesulfonate, melting at about 112-115° C. and displaying an optical rotation of [α] 25 D =-23.9°(c=1, chloroform). That compound displays a characteristic NMR spectra in deuterochloroform of τ=9.0 (doublet, J=2), 6.85, 6.70, 6.61, 6.07, 4.89 (quartet, J=2), 1.99-2.88 (multiplet).
EXAMPLE 17
To a solution of 7 grams of sodium acetate in 50 ml. of acetic acid is added 3 grams of (S) 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)prop-2-yl methanesulfonate. The mixture is heated to about 110° C. for about 1.5 hours and then poured into 300 ml. of water. The precipitate is recovered by filtration and washed with methanol to afford (S) methyl 2-(6-methoxy-2-naphthyl)propionate, melting at about 85-87° C. and displaying an optical rotation of [α] 25 D =+65.4° (c=1, chloroform). That material is a 92% optically pure.
EXAMPLE 18
Substitution of an equivalent quantity of (S) 1-(6-methoxy-2-naphthyl)-2-p-toluenesulfonyloxypropan-1-one in Example 16 and proceeding according to that Example affords (S) 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)prop-2-yl p-toluenesulfonate. Treatment of that material in a manner similar to that described in Example 17 affords (S) methyl 2-(6-methoxy-2-naphthyl)propionate.
EXAMPLE 19
Substitution of an equivalent quantity of (S) 2-benzenesulfonyloxy-1-(6-methoxy-2-naphthyl)propan-1-one in the procedure of Example 16 and proceeding according to that Example affords (S) 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)prop-2-yl benzenesulfonate. Treatment of that material in a manner similar to that described in Example 17 affords (S) methyl 2-(6-methoxy-2-naphthyl)propionate.
EXAMPLE 20
The (R) 2-methanesulfonyloxy-1-(6-methoxy-2-naphthyl)-propan-1-one prepared in Example 13 is treated with a 1.5 molar excess of sodium methoxide in methanol solution. That mixture is stirred for about 1 hour at room temperature and the methanol is stripped from the mixture at about 50° C. on a rotary evaporator until approximately 80% of the methanol has been removed. The resulting reaction mixture is quenched in water and extracted with methylene chloride. The organic layer is separated, dried over magnesium sulfate and evaporated under reduced pressure to afford (S) 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)propan-2-ol. That material is dissolved in methylene chloride containing triethylamine and the reaction mixture is cooled to about 5° C. and one equivalent of methanesulfonyl chloride is added slowly, maintaining the temperature between 5-10° C. After the addition of the methanesulfonyl chloride has been completed, the reaction mixture is stirred for an additional 1/2 hour. Then the solution is filtered to remove the triethylamine hydrochloride crystals and the filtrate is poured into water. The organic layer is separated and dried over magnesium sulfate. Evaporation of the organic layer under reduced pressure affords (S) 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)prop-2-yl methanesulfonate. That material is treated in a manner similar to Example 17 to afford (S) methyl 2-(6-methoxy-2-naphthyl)propionate.
EXAMPLE 21
An equivalent quantity of each of the following materials: (S) 2-chloropropionyl chloride, (S) 2-bromopropionyl chloride, (R) 2-chloropropionyl chloride and (R) 2-bromopropionyl chloride prepared by the method of Fu et al, JACS, 76,6054 (1954) is substituted for (S) 2-methanesulfonyloxypropionyl chloride in Example 10, and the procedure of that Example is otherwise followed to afford, respectively,
(S) 2-chloro-1-(6-methoxy-2-naphthyl)propan-1-one,
(S) 2-bromo-1-(6-methoxy-2-naphthyl)propan-1-one,
(R) 2-chloro-1-(6-methoxy-2-naphthyl)propan-1-one, and
(R) 2-bromo-1-(6-methoxy-2-naphthyl)propan-1-one.
EXAMPLE 22
The following compounds are prepared from the compounds of Example 21 in a manner similar to that described in European Patent Office Application No. 81200210.3, filed Feb. 23, 1981 [EPO publication number 0034871, published Sep. 2, 1981]:
(a) From (S) 2-chloro-1-(6-methoxy-2-naphthyl)propan-1-one:
(1) (S) 2-chloro™1,1-dimethoxy-1-(6-methoxy-2-naphthyl)propane
(2) (S) 2-chloro-1,1-diethoxy-(6-methoxy-2-naphthyl)propane
(3) (S) 2-chloro-1-(6-methoxy-2-naphthyl)-propan-1-one ethylene acetal
(4) (S) 2-chloro-1-(6-methoxy-2-naphthyl)-propan-1-one propylene acetal
(5) (S) 2-chloro-1-(6-methoxy-2-naphthyl)-propan-1-one 1,2-dimethylethylene acetal
(b) From (S) 2-bromo-1-(6-methoxy-2-naphthyl)propan-1-one:
(1) (S) 2-bromo-1,1-dimethoxy-(6-methoxy-2-naphthyl)propane
(2) (S) 2-bromo-1,1-diethoxy-(6-methoxy-2-naphthyl)propane
(3) (S) 2-bromo-1-(6-methoxy-2-naphthyl) propan-1-one ethylene acetal
(4) (S)2-bromo-1-(6-methoxy-2-naphthyl)propan-1-one propylene acetal
(5) (S)2-bromo-1-(6-methoxy-2-naphthyl)propan-1-one 1,2-dimethylethylene acetal.
EXAMPLE 23
The materials prepared in Example 22 are each rearranged in a manner similar to that described in EPO Application No 81200210.3, filed Feb. 23, 1981 [EPO publication no. 0034871, published Sep. 2, 1981], with the following Lewis acids: barium chloride, bismuth chloride, calcium chloride, cadmium chloride, cobalt chloride, cuprous chloride, ferrous chloride, ferric chloride, mercurous chloride, magnesium chloride, manganese bromide, manganese chloride, nickel bromide, paladium chloride, antimony chloride, stannous chloride, stannic chloride, zinc bromide, zinc chloride and zinc diacetate: to afford, after hydrolosis of any ester formed, (S) 2-(6-methoxy-2-naphthyl)propionic acid.
EXAMPLE 24
The following compounds prepared in Example 21: (R) 2-chloro-1-(6-methoxy-2-naphthyl)propan-1-one and (R) 2-bromo-1-(6-methoxy-2-naphthyl)propan-1-one are each allowed to react with at least an equimolar amount of sodium methoxide in at least an equimolar amount of methanol, to afford in each instance, (S) 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)propan-2-ol
EXAMPLE 25
(S) 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)propan-2-ol is treated with a molar excess (up to 50% excess) of methanesulfonyl chloride in the presence of a molar excess of triethylamine (equal to or greater than the molar excess of methanesulfonyl chloride) in methylene chloride to afford (S) 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)prop-2-yl methanesulfonate. That material is converted to (S) methyl 2-(6-methoxy-2-naphthyl)propionate in a manner similar to that described in Example 17.
EXAMPLE 26
(S) 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)propan-2-ol is treated with a molar excess of p-toluenesulfonyl chloride in the presence of a molar excess of triethylamine in a manner similar to Example 25 to yield (S) 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)prop-2-yl p-toluenesulfonate. That material is converted to (S) methyl 2-(6-methoxy-2-naphthyl)propionate in a manner similar to that described in Example 17.
EXAMPLE 27
The process described in Example 26 is repeated by substituting benzenesulfonyl chloride for the p-toluenesulfonyl chloride recited in that Example to afford (S) 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)prop-2-yl benzenesulfonate. That material is converted to (S) methyl 2-(6-methoxy-2-naphthyl)propionate in a manner similar to that described in Example 17.
EXAMPLE 28
A solution containing 6 ml. of anhydrous methylene chloride and 1.0 millimole of (S) 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)prop-2-yl p-toluenesulfonate is added dropwise to a stirred mixture of 0.20 ml. of iodotrimethylsilane and one drop of cyclohexene in 8 ml. of anhydrous methylene chloride at room temperature under an argon atmosphere The mixture is stirred for about 1 hour at room temperature and 10 ml. of saturated aqueous sodium bicarbonate is added. The organic and aqueous layers are separated and the organic layer is washed successively with 5 ml. of 10% aqueous sodium thiosulfate, 5 ml. of water, 5 ml. of aqueous sodium bicarbonate and 5 ml. of water. Then the organic layer is dried over magnesium sulfate to afford, upon evaporation of the solvent, (S) methyl 2-(6-methoxy-2-naphthyl)propionate.
EXAMPLE 29
In a manner similar to that employed in Example 28, (S) 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)prop-2-yl p-toluenesulfonate is converted to (S) methyl 2-(6-methoxy-2-naphthyl)propionate.
EXAMPLE 30
In a manner similar to that described in Example 28, (S) 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)prop-2-yl benzenesulfonate is converted to (S) methyl 2-(6-methoxy-2-naphthyl)propionate.
EXAMPLE 31
The materials prepared in Example 22 are each rearranged in a manner similar to that described in British Patent No. 8005752, filed Feb. 20, 1980 [publication number 2042543, published Sep. 24, 1980] with the following silver salts:
(1) silver tetrafluoroborate and BF 3 .2CH 3 OH
(2) silver carbonate and BF 3 .2CH 3 OH
(3) silver acetate and BF 3 .2CH 3 OH
(4) silver oxide and BF 3 .2CH 3 OH
(5) silver tetrafluoroborate in methanol.
to yield, after hydrolosis of any ester formed, (S) 2-(6-methoxy-2-naphthyl)propionic acid.
EXAMPLE 32
A slurry of 2 grams of (S) 2-methanesulfonyloxy-1-(6-methoxy-2-naphthyl)propan-1-one in 35 ml. of methanol is cooled to 10° C. and 0.21 grams of sodium borohydride are added in four portions while maintaining the temperature at about 10° C. That mixture is stirred for 11/2 hours, poured into an aqueous 10% acetic acid solution and extracted with methylene chloride. The organic and aqueous phases are separated and the organic phase is washed with aqueous sodium bicarbonate solution and dried over magnesium sulfate. Evaporation of the solvent affords (S) 1-hydroxy-1-(6-methoxy-2-naphthyl)prop-2-yl methanesulfonate, as a solid. That compound displays a characteristic NMR spectra in deuterochloroform of δ=1.2 (doublet, J=2), 2.91, 3.44 (doublet, J=2.2), 3.87, 4.80 (multiplet, J=2.2,2), 7.7-7.1 (multiplet).
EXAMPLE 33
A mixture prepared from 1.2 grams of (S) 1-hydroxy-1-(6-methoxy-2-naphthyl)prop-2-yl methanesulfonate prepared according to Example 32, 20 ml. of acetic acid and 1.6 grams of sodium acetate is heated to about 45° C. and maintained at that temperature for about 61/2 hours. The mixture is poured into water and extracted with ethyl ether. The ethereal layer is washed several times with water, once with aqueous sodium bicarbonate solution, and dried over magnesium sulfate. Evaporation of the ethyl ether yields, as an oil, (S) 2-(6-methoxy-2-naphthyl)-propanal. That material crystallizes upon standing and exhibits a melting point of about 71-72° C. and an [α] 25 D =+37°.
EXAMPLE 34
Equivalent quantities of (S) 2-benzenesulfonyloxy-1-(6-methoxy-2-naphthyl)propan-1-one and 1-(6-methoxy-2-naphthyl)-2-p-toluenesulfonyloxypropan-1-one are each processed according to the procedures outlined in Examples 32 and 33 to afford, in each instance, (S) 2-(6-methoxy-2-naphthyl)propanal.
EXAMPLE 35
A mixture of 90 grams of ethylene glycol, 30 grams of (S) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one, 6 grams of p-toluenesulfonic acid monohydrate and 400 ml. of toluene is heated to reflux. An azeotrope of toluene, water and ethylene glycol is removed, and the water and ethylene glycol separate upon cooling and are removed via a Dean Stark trap. The reaction mixture is azeotropically dried for 5 hours and then cooled. The cooled mixture is poured into excess aqueous sodium bicarbonate, and the toluene layer is separated and dried over magnesium sulfate.
The toluene is removed by evaporation and the solid remaining is stirred in methanol to yield, after filtration, (S) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxy-propan-1-one ethylene acetal, displaying an optical rotation of [α] 25 D =+6.1° (C=1, chloroform). That compound displays a characteristic NMR spectra in deuterochloroform of δ=1.35 (doublet, J=2), 2.78, 3.83, 3.98-3.68 (multiplet), 4.28-4.0 (multiplet), 4.98 (quartet, J=2), 8-7 (multiplet).
EXAMPLE 36
A suitable pressure reactor is charged with 6.4 grams of (S) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one ethylene acetal, 60 ml of 1,2-diethoxyethane, 50 ml. of water and 3 grams of calcium carbonate. The mixture is heated while being stirred at 120° C. for 36 hours at 42 psi. Then the mixture is cooled and the calcium salts removed by filtration. Concentrated hydrochloric acid is added and the mixture is reheated to 95° C. for 3 hours. Then the 1,2-diethoxyethane is removed by distillation to yield a solid which is extracted with ethyl ether. The organic layer is back extracted with aqueous sodium bicarbonate and the aqueous and organic layers are separated. The aqueous layer is acidified with hydrochloric acid to afford, after filtration, (S) 2-(6-methoxy-2-naphthyl) propionic acid, exhibiting a melting point of 147° C.-150° C. and an optical rotation of [α] 25 D =+62.2° in chloroform.
EXAMPLE 37
The procedure of Example 36 is repeated using dimethylformamide in place of the 1,2-dimethoxyethane. The mixture is heated to 110° C. at atmospheric pressure for 24 hours. After workup, there is obtained (S) 2-hydroxyethyl 2-(6-methoxy-2-naphthyl)propionate by preparative TLC. That material exhibits an [α] 25 D =+72.5°. That material exhibits a character NMR spectra in deuterochloroform of δ=1.49 (doublet, J=2.3), 3.67 (multiplet), 3.85, 3.89 (quartet, J-2.3), 4.17 (multiplet), 7.77-7.07 (multiplet).
EXAMPLE 38
A solution of 20.98 mmoles of (S) 2-methanesulfonyloxypropionic acid, 20.95 mmoles of triethylamine and 48 ml. of anhydrous tetrahydrofuran is prepared in a dry vessel under nitrogen and cooled to -30° C. The solution is stirred for about 5 minutes at -30° C., and then 231.23 mmoles of trimethylacetyl chloride are added. A white precipitate is observed. The mixture is allowed to warm to -20° C., and it is stirred at that temperature for 30 minutes. The resulting white slurry is cooled to about -70° C. and 20.98 mmoles of the Grignard reagent prepared from 2-bromo-6-methoxynaphthalene in tetrahydrofuran are added over a one hour period. The mixture is stirred for four hours at -70° C. and then allowed to warm to -20° C. Then it is poured into 150 ml. of dilute hydrochloric acid and extracted with methylene chloride. The organic extracts are evaporated to dryness and the remaining material is extracted with ethyl ether. The resulting slurry is filtered, to afford (S) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one, exhibiting a melting point of about 150-154° C.
EXAMPLE 39
A mixture of 47.2 mmoles of lithium chloride and 21.3 mmoles of manganese chloride in 50 ml of anhydrous tetrahydrofuran is stirred at 25° C. until a yellow solution is formed Then the Grignard prepared from 19.8 mmoles of 6-methoxy-2-bromonaphthalene in tetrahydrofuran is added at -30° C. That mixture is stirred at -30° C. for 1.5 hours and then at 25° C. for 20 minutes. The solution of (6-methoxy-2-napthyl)manganese chloride is added to 22.3 mmoles of (S) 2-methanesulfonyloxypropionyl chloride in 30 ml. of tetrahydrofuran material at -20° C. The mixture is stirred for 1 hour at -20° C., then allowed to warm to 25° C., at which temperature it is stirred for an additional hour. After that time, the mixture is poured into 150 ml of dilute aqueous hydrochloric acid and extracted with methylene chloride. The methylene chloride is removed by evaporation under reduced pressure and ethyl ether is added. The ethereal slurry is filtered to afford (S) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one, melting at about 148-150° C.
EXAMPLE 40
A dry flask is charged with 80.6 mmoles of imidazole and 50 ml. of anhydrous tetrahydrofuran. Then a solution of 40.3 mmoles of (S) 2-methanesulfonyloxypropionyl chloride in 50 ml. of tetrahydrofuran is added dropwise at room temperature. A white precipitate begins to form during the addition period. The mixture is allowed to stir at room temperature for 2.5 hours, and the resulting white slurry is filtered to remove the imidazole hydrochloride salt. The filtrate, containing 1-(2-methanesulfonyloxypropionyl)imidazole, is cooled to -10° C. under nitrogen and 40.0 mmoles of the magnesium Grignard of 2-bromo-6-methoxynaphthalene in tetrahydrofuran is added dropwise at -70° C. to -60° C. The mixture is stirred for 40 minutes, allowed to warm to 10° C. and poured into 150 ml. of dilute hydrochloric acid. That mixture is extracted with methylene chloride and the organic extracts are evaporated to dryness. The solid is washed with ethyl ether and dried to afford (S) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one, exhibiting an [α] 25 D =-29.2° in methylene chloride.
EXAMPLE 41
An appropriately sized dry vessel is charged with 20 grams of magnesium shavings and 15 ml. of anhydrous tetrahydrofuran. The stirred mixture is warmed to 50°-60° C. and treated with a solution of 16.6 grams of 2-bromo-6-methoxynaphthalene in 35 ml. of anhydrous tetrahydrofuran. Then the mixture is stirred for one hour at 50-60° C. The Grignard solution is transferred to another dry vessel and cooled to 25°. 4.8 Grams of powdered zinc chloride is added to the stirred Grignard solution and the temperature of the mixture is allowed to rise to 45-50° C. to afford a solution containing di(6-methoxy-2-naphthyl)zinc.
EXAMPLE 42
A solution of 15.7 grams of (S) 2-methanesulfonyloxypropionyl chloride in 94 ml. of dry tetrahydrofuran is cooled, with stirring, to -60° C. Then the solution of di(6-methoxy-2-naphthyl)zinc prepared in Example 42 is added over a four hour period. After the addition is completed, the reaction mixture is allowed to warm to 25° C. over a 15 hour period. The resulting mixture is added to a stirred mixture containing 30 ml. of concentrated hydrochloric acid and 200 ml. of water. 50 Ml of diethyl ether is added and the resulting slurry is filtered and dried under reduced pressure at 40° C. to yield (S) 1-(6-methoxy-2-naphthyl)-2-methanesulfonyloxypropan-1-one.
EXAMPLE 43
A mixture of 3.07 grams of (S) 1,1-dimethoxy-1-(6-methoxy-2-naphthyl)prop-2-yl methanesulfonate, 1.0 gram of calcium carbonate, 100 ml. of dimethylformamide and 25 ml. of water is heated to 110° C. and maintained at that temperature for 5 hours. Then the mixture is cooled and the insolubles removed by filtration. The filtrate is poured into excess water and the solid which forms is collected by filtration. Separation by chromatography yields methyl 2-(6-methoxy-2-naphthyl)propionate, exhibiting an [α] 25 D =77° in chloroform and an optical purity of greater than 99 percent.
While this invention has been described in reference to specific embodiments thereof, it should be understood by those skilled in the art that various changes can be made and equivalents may be substituted without departing from the true spirit and scope of the invention. All such modifications are intended to be within the scope of the claims appended hereto.
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Optically active naphthyl alpha-substituted alkyl ketones, are a class of ketones useful as intermediates in the production of optically active alpha-naphthylalkanoic acids which exhibit anti-inflammatory, analgesic and anti-pyretic activity.
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CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 61/168,683 filed Apr. 13, 2009, entitled “DIESEL POWERED SEMI-TRAILER TRUCK,” which is hereby incorporated herein by reference in its entirety, including all references cited therein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates in general to an improved vehicle and, more particularly, but not by way of limitation, to an improved diesel powered semi-trailer truck having a secondary hydrogen fuel source and a secondary cooling fan cooperating together to improve the fuel efficiency of the improved semi-trailer truck.
[0004] 2. Background Art
[0005] Diesel powered semi-trailer trucks are well known in the art. While diesel powered trucks are known in the art, they suffer from numerous drawbacks including, but not limited to, poor diesel engine performance caused by less than optimal fuel efficiency, the build up of carbon deposits within the combustion chamber of the diesel engine and unnecessary overuse and/or redundant use of certain engine components (e.g., the cooling fan). In general, a diesel powered truck comprises a glider kit in combination with a diesel powered engine. The glider kit includes a chassis with a cab, a plurality of wheels connected to a steering and braking system and optionally a plurality of other accessories. The diesel powered engine includes a primary fuel pump providing diesel fuel, a cooling system which includes a cooling fan and a radiator, and an exhaust system that carries away combustion gases produced by the diesel powered engine.
[0006] Because of the weight of the truck and the aforementioned deficiencies inherent in the operation of common diesel powered trucks, the overall fuel efficiency of such diesel powered trucks is substantially reduced.
[0007] Thus the need exists for an improved diesel powered truck that includes a secondary hydrogen fuel source providing hydrogen to the diesel engine and a secondary fan that can be operated in lieu of, or in concert with the primary cooling fan of the diesel engine to enhance the fuel efficiency of the same.
SUMMARY OF THE INVENTION
[0008] In one embodiment, the present invention is directed to an improved vehicle, the improved vehicle comprising a semi-trailer truck glider kit in combination with a diesel powered engine, the diesel powered engine having a combustion chamber, a primary diesel fuel source and a primary cooling fan, the diesel engine being adapted to operate on a diesel fuel, hydrogen and air mixture received by the combustion chamber, the improvement comprising: (a) a hydrogen generator providing hydrogen to the combustion chamber of the diesel powered engine, the combustion chamber combining hydrogen and air with the diesel fuel for improving the efficiency of the diesel powered engine and substantially preventing unwanted organic residue produced by the combustion of the diesel fuel; (b) a secondary cooling fan connected to the diesel powered engine; and (c) a control system controlling the operation of at least one of the generator, the primary cooling fan and the secondary cooling fan to enhance the performance of the vehicle.
[0009] In another embodiment, the control system comprises a valve for delivering the hydrogen and air mixture at a selectively adjustable rate, the valve having a fuel inlet, a fuel outlet, and a fuel passage therebetween, wherein the fuel inlet is in fluid communication with the hydrogen generator and the fuel outlet is in fluid communication with the combustion chamber of the diesel powered engine.
[0010] In yet another embodiment, the improved vehicle further comprises an engine sensor in electrical communication with the control system and sensing at least one operating parameter of the diesel powered engine, and wherein the control system selectively permits the primary cooling fan and the secondary cooling fan to operate independently of one another responsive to the at least one parameter of the diesel powered engine.
[0011] In a preferred embodiment, the engine sensor continuously monitors the fuel efficiency of the diesel powered engine and causes the control system to increase the amount of hydrogen provided to the combustion chamber of the diesel powered engine when the diesel powered engine operates at a fuel efficiency of less than 25 miles per gallon.
[0012] In one embodiment, the engine sensor continuously monitors the operation of a turbocharger of the diesel powered engine to reduce the use of the same by modifying a gear ratio of a transmission of the diesel powered engine.
[0013] In another embodiment, the control system causes the hydrogen generator to deliver hydrogen to the combustion chamber at a selectively adjustable rate such that the diesel powered engine can be operated in excess of 30,000 miles without replacing at least one of an engine oil and an air filter of the diesel powered engine.
[0014] In yet another embodiment, the control system causes the hydrogen generator to deliver hydrogen to the combustion chamber at a selectively adjustable rate such that the diesel powered engine can be operated in excess of 30,000 miles without replacing both of an engine oil and an air filter of the diesel powered engine.
[0015] In another embodiment, the control system causes the primary cooling fan to cease operation and the secondary cooling fan to operate when the diesel powered engine is operated at ambient temperatures less than 30 degrees Fahrenheit.
[0016] In one embodiment the present invention is directed to an improved vehicle comprising a semi-trailer truck glider kit in combination with a diesel powered engine, the diesel powered engine having a combustion chamber, a primary diesel fuel source and a primary cooling fan, the diesel engine being adapted to operate on a diesel fuel, hydrogen and air mixture received by the combustion chamber, the improvement comprising: (a) a hydrogen generator providing a mixture of hydrogen and oxygen to the combustion chamber of the diesel powered engine, the combustion chamber receiving hydrogen, oxygen and air combined with the diesel fuel for improving the efficiency of the diesel powered engine and substantially preventing unwanted organic residue produced by the combustion of the diesel fuel; (b) a secondary cooling fan connected to the diesel powered engine; and (c) a control system controlling the operation of at least one of the hydrogen generator, the primary cooling fan and the secondary cooling fan to enhance the performance of the vehicle, wherein the control system comprises a valve for delivering a mixture of hydrogen and air at a selectively adjustable rate, the valve having a fuel inlet, a fuel outlet, and a fuel passage therebetween, wherein the fuel inlet is in fluid communication with the hydrogen generator and the fuel outlet is in fluid communication with the combustion chamber of the diesel powered engine.
[0017] In another embodiment, the improved vehicle comprises an engine sensor in electrical communication with the control system and sensing at least one operating parameter of the diesel powered engine, and wherein the control system selectively permits the primary cooling fan and the secondary cooling fan to operate independently of one another responsive to the at least one parameter of the diesel powered engine.
[0018] In yet another embodiment, the engine sensor continuously monitors the fuel efficiency of the diesel powered engine and causes the control system to increase the amount of hydrogen and air provided to the combustion chamber of the diesel powered engine when the diesel powered engine operates at a fuel efficiency of less than 25 miles per gallon.
[0019] In a preferred embodiment, the control system delivers a hydrogen and oxygen mixture to the combustion chamber at a selectively adjustable rate such that the diesel powered engine can be operated in excess of 30,000 miles without replacing at least one of an engine oil and an air filter of the diesel powered engine.
[0020] In another preferred embodiment, the control system causes the hydrogen generator to deliver hydrogen to the combustion chamber at a selectively adjustable rate such that the diesel powered engine can be operated in excess of 30,000 miles without replacing both of an engine oil and an air filter of the diesel powered engine.
[0021] In another embodiment, the control system causes the primary cooling fan to cease operation and the secondary cooling fan to operate when the diesel powered engine is operated at ambient temperatures less than 30 degrees Fahrenheit.
[0022] In another embodiment, the present invention is directed to an improved vehicle, the improved vehicle comprising a semi-trailer truck glider kit in combination with a diesel powered engine, the diesel powered engine having a combustion chamber, a primary diesel fuel source and a primary cooling fan, the diesel engine being adapted to operate on a diesel fuel, hydrogen and air mixture received by the combustion chamber, the improvement comprising: (a) a hydrogen generator providing a mixture of hydrogen and oxygen to the combustion chamber of the diesel powered engine, the combustion chamber receiving hydrogen, oxygen and air combined with the diesel fuel for improving the efficiency of the diesel powered engine and substantially preventing unwanted organic residue produced by the combustion of the diesel fuel; (b) a secondary cooling fan connected to the diesel powered engine; (c) a control system controlling the operation of at least one of the hydrogen generator, the primary cooling fan and the secondary cooling fan to enhance the performance of the vehicle; and (d) an engine sensor in electrical communication with the control system and sensing at least one operating parameter of the diesel powered engine, and wherein the control system selectively permits the primary cooling fan and the secondary cooling fan to operate independently of one another responsive to the at least one parameter of the diesel powered engine.
[0023] In another embodiment, the engine sensor continuously monitors the fuel efficiency of the diesel powered engine and causes the control system to increase the amount of hydrogen and oxygen provided to the combustion chamber of the diesel powered engine when the diesel powered engine operates at a fuel efficiency of less than 25 miles per gallon.
[0024] In a preferred embodiment, the control system delivers a hydrogen and oxygen mixture to the combustion chamber at a selectively adjustable rate such that the diesel powered engine can be operated in excess of 30,000 miles without replacing at least one of an engine oil and an air filter of the diesel powered engine.
[0025] In yet another embodiment, the control system causes the hydrogen generator to deliver hydrogen to the combustion chamber at a selectively adjustable rate such that the diesel powered engine can be operated in excess of 30,000 miles without replacing both of an engine oil and an air filter of the diesel powered engine.
[0026] In one embodiment, the control system causes the primary cooling fan to cease operation and the secondary cooling fan to operate when the diesel powered engine is operated at ambient temperatures less than 30 degrees Fahrenheit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Certain embodiments of the present invention are illustrated by the accompanying FIGURE. It will be understood that the FIGURE is not necessarily to scale and that details not necessary for an understanding of the invention or that render other details difficult to perceive may be omitted. It will be understood that the invention is not necessarily limited to the particular embodiments illustrated herein.
[0028] The invention will now be described with reference to the drawing wherein:
[0029] FIG. 1 of the drawings is schematic representation of the improved semi-trailer truck, in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0030] While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail several specific embodiments with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiments illustrated.
[0031] It will be understood that like or analogous elements and/or components, referred to herein, may be identified throughout the drawings with like reference characters.
[0032] Referring now to FIG. 1 , shown therein is a schematic representation of an improved semi-trailer truck 10 including a diesel engine 12 . Although not shown, the improved semi-trailer truck 10 includes a semi-trailer truck glider kit that generally comprises all of the components of a semi-trailer truck less the power train, which in this case preferably comprises the diesel engine 12 . As stated previously, the glider kit includes a cab, a chassis with a plurality of wheels rotatably connected to the chassis, a braking system, an exhaust system and other various accessories, for example, mirrors, lighting and the like. Therefore, the diesel engine 12 , provided in combination with the glider kit comprises a standard, operational semi-trailer truck.
[0033] In one embodiment, the preferred diesel engine 12 selected for use in accordance with the present invention includes, for example, a Detroit Diesel Series 60 Recon Engine produced by the Detroit Diesel Corporation. It will be understood that other diesel engines 12 may be utilized so long as the diesel engine 12 utilized is capable of being adapted to operate on a mixture of diesel fuel and hydrogen fuel. Therefore, other diesel engines that would be known to one of ordinary skill in the art with the present disclosure before them are likewise contemplated for use in accordance with the present invention. The diesel engine 12 includes a cooling system comprising a primary cooling fan 14 operating in concert with a radiator (not shown) to transfer heat energy produced by the diesel engine 12 to improve the efficiency of the diesel engine 12 , a transmission 16 connected to the diesel engine 12 , a turbocharger 17 connected to the diesel engine 12 , and a combustion chamber 18 (e.g., a plurality of cylinders of the engine) for mixing and delivering air, fuel and/or hydrogen for combustion in the diesel engine 12 .
[0034] The semi-trailer truck 10 additionally includes a primary diesel fuel source, for example, a primary fuel pump 20 providing diesel fuel to the combustion chamber 18 of the diesel engine 12 , a hydrogen generator 22 providing hydrogen and/or oxygen to the combustion chamber 18 of the diesel engine 12 and a secondary cooling fan 24 .
[0035] In one embodiment, the preferred hydrogen generator 22 selected for use in accordance with the present invention includes, for example, a Jetstar™ produced by Dynamic Fuel Systems Incorporated. It will be understood that other hydrogen generators 22 may be utilized so long as the hydrogen generator 22 utilized is capable of being adapted to provide hydrogen and/or oxygen to the combustion chamber 18 of the diesel engine 12 . Therefore, other hydrogen generators 22 that would be known to one of ordinary skill in the art with the present disclosure before them are likewise contemplated for use in accordance with the present invention.
[0036] In particular, the hydrogen generator 22 gasifies a hydrogen compatible fuel, for example, Jetfuel™ also produced by Dynamic Fuel Systems Incorporated, by separating the hydrogen and oxygen molecules contained within the fuel to produce hydrogen and oxygen gases. These gases are produced only while the diesel engine 12 is running and are produced under a slight pressure to ensure a consistent flow to the combustion chamber 18 of the diesel engine 12 . The hydrogen generator 22 preferably draws only a small amount of power from the vehicle's electrical system (not shown) and therefore only negligibly affects fuel economy. With the addition of the hydrogen generator 22 , the combustion process is preferably more efficient. More specifically, emissions such as nitrous oxides, hydrocarbons and carbon monoxide are substantially reduced both over time and distance. Also, the addition of a hydrogen and air mixture into the combustion chamber 18 allows the primary diesel fuel to burn within the diesel engine 12 more completely. Therefore, the hydrogen generator 22 may increase horsepower and, correspondingly, increase fuel mileage, resulting in lower maintenance and/or operating costs. For example, the inclusion of the hydrogen and air mixture may result in a substantially cleaner combustion chamber (not shown) relative to a diesel engine 12 without a hydrogen generator 22 . By way of non-limiting example, the improved semi-trailer truck 10 may preferably operate in excess of 30,000 miles without need of changing the oil and/or the air filter utilized by the diesel engine 12 .
[0037] An example of the hydrogen generator 22 along with details for installation and use of the same are discussed in at least the following reference, U.S. Patent Application Publication No. 2008/0047830, filed by Fairfull et al., the details of which are incorporated by reference herein in their entirety.
[0038] In one embodiment, the preferred secondary cooling fan 24 selected for use in accordance with the present invention includes, for example, an electric fan. It will be understood that other secondary cooling fans 24 may be utilized so long as the secondary cooling fan 24 utilized is capable of being operated in combination with the primary cooling fan 14 or in some cases, in lieu of the primary cooling fan 14 as will be discussed in greater detail infra. Therefore, other secondary cooling fans 24 that would be known to one of ordinary skill in the art with the present disclosure before them are likewise contemplated for use in accordance with the present invention.
[0039] The secondary cooling fan 24 is preferably a smaller sized fan (e.g., reduced electrical energy consumption) relative to the primary cooling fan 14 . The secondary cooling fan 24 may be powered by, for example, an electrical current produced by the diesel engine 12 or other parts of the vehicle (e.g., an alternator or battery). The secondary cooling fan 24 is provided to work either concurrently or in lieu of the primary cooling fan 14 . For example, when the diesel engine 12 of the semi-trailer truck 10 is operated under strenuous conditions such as driving uphill, the secondary cooling fan 24 works in concert with the primary cooling fan 14 to remove excess heat generated by the diesel engine 12 . In contrast, when the diesel engine 12 is operated under lighter conditions, such as driving in the city on a cold day (e.g., temperatures lower than 30 degrees Fahrenheit), the diesel engine 12 produces less heat. Therefore, the primary cooling fan 14 is temporarily rendered inoperative such that the secondary cooling fan 24 is operating alone. As the secondary cooling fan 24 requires less electrical energy to operate than the primary cooling fan 14 , the secondary cooling fan 24 allows the diesel engine 12 to operate more efficiently than the diesel engine 12 utilizing the primary cooling fan 14 exclusively.
[0040] Examples of secondary cooling fans are discussed in at least the following references, U.S. Pat. No. 4,677,941, issued to Kurz, and U.S. Pat. No. 4,409,933, issued to Inoue, the details of which are incorporated by reference herein in their entirety.
[0041] The semi-trailer truck 10 preferably includes an electrical sensor 26 in electrical communication with a control system 28 . The electrical sensor 26 senses or monitors at least one operating parameter of the diesel engine 12 , for example, speed, revolutions per minute, fuel consumption, engine temperature, ambient temperature, and/or combinations thereof. The electrical sensor 26 outputs data to the control system 28 for optimizing the fuel efficiency of the diesel engine 12 by controlling the operation of various components of the diesel engine 12 . More specifically, the control system 28 is adapted to control the operation of at least the primary cooling fan 14 , the secondary cooling fan 24 , the primary fuel pump 20 and the hydrogen generator 22 .
[0042] In one embodiment, the control system 28 includes a valve (not shown) for delivering hydrogen and/or oxygen from the hydrogen generator 22 at a selectively adjustable rate. By way of non-limiting example, the valve is preferably provided with a fuel inlet, a fuel outlet, and a fuel passage therebetween. The fuel inlet is in fluid communication with the hydrogen generator 22 and the fuel outlet is in fluid communication with the combustion chamber 18 of the diesel engine 12 .
[0043] With respect to the primary and secondary cooling fans 14 and 24 respectively, when the electrical sensor 26 senses that the diesel engine 12 is operating under strenuous conditions such as driving uphill, the electrical sensor 26 communicates an electrical signal to the control system 28 which in turn communicates an electrical signal to the secondary cooling fan 24 to cause the secondary cooling fan 24 to operate in concert with the primary cooling fan 14 to remove excess heat generated by the diesel engine 12 . In contrast, when the diesel engine 12 is operated under lighter conditions, such as driving in the city on a cold day (e.g., temperatures lower than 30 degrees Fahrenheit), the electrical sensor 26 communicates an electrical signal to the control system 28 which in turn communicates an electrical signal to the primary cooling fan 14 rendering it temporarily inoperative such that the secondary cooling fan 24 is operating alone.
[0044] With respect to the primary fuel pump 20 and the hydrogen generator 22 , under typical operating conditions, for example, when the diesel engine 12 operates at a constant 1,800 revolutions per minute, the electrical sensor 26 communicates an electrical signal to the control system 28 which communicates with the hydrogen generator 22 to deliver a substantially constant amount of hydrogen and/or oxygen and a substantially constant amount of diesel fuel from the primary fuel source 20 to the combustion chamber 18 of the diesel engine 12 . When the diesel engine 12 operates at higher revolution per minute, for example, when the semi-trailer truck 10 is operating on a hill, the electrical sensor 26 communicates an electrical signal to the control system 28 which communicates with the hydrogen generator 22 to deliver a greater amount of hydrogen and/or oxygen to the combustion chamber 18 of the diesel engine 12 than when the diesel engine 12 is operating at substantially constant rate of 1,800 revolutions per minute.
[0045] In one embodiment, the engine sensor 26 continuously monitors the fuel efficiency of the diesel engine 12 and causes the control system 28 to increase the amount of hydrogen and/or oxygen provided to the combustion chamber 18 by the hydrogen generator 22 when the diesel powered engine operates at a fuel efficiency of less than 25 miles per gallon. It will be understood that during any and all operation of the diesel engine 12 , the control system 28 selectively controls the operation of both the primary fuel source 20 and the hydrogen generator 22 to maximize the fuel efficiency of the diesel engine 12 .
[0046] In another embodiment, the engine sensor 26 continuously monitors the operation of a turbocharger 17 of the diesel engine 12 to reduce the use of the same by modifying a gear ratio of the transmission 16 of the diesel engine 12 .
[0047] Additionally, it will be understood that typical semi-trailer trucks having diesel engines adapted to operate on a hydrogen enhanced fuel mixture may preferably be retrofit with a hydrogen generator 22 , secondary cooling fan 24 , electrical sensor 26 and control system 28 to produce an improved semi-trailer truck 10 .
[0048] The foregoing description merely explains and illustrates the invention and the invention is not limited thereto except insofar as the appended claims are so limited, as those skilled in the art who have the disclosure before them will be able to make modifications without departing from the scope of the invention.
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An improved vehicle having a hydrogen generator providing a mixture of hydrogen and/or oxygen to a combustion chamber of a diesel powered engine which is combined with diesel fuel for improving the efficiency of the diesel powered engine and substantially preventing unwanted organic residue produced by the combustion of the diesel fuel, a secondary cooling fan connected to the diesel powered engine; and a control system controlling the operation of at least one of the generator, the primary cooling fan and the secondary cooling fan to enhance the performance of the vehicle.
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[0001] The present application is based on Japanese Patent Applications No. 2002-225145, No. 2002-334419 and No. 2003-090812, 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 linear luminous body. For example, the linear luminous body according to the invention is used for interior decoration.
[0004] Further, the present invention relates to a structure having linear luminous bodies connected to one another by connectors. For example, the linear luminous structure according to the invention is used for interior decoration, outdoor character advertisement, etc.
[0005] 2. Related Art
[0006] A linear decorative body is used for the purposes of interior decoration, outdoor information display, etc. For example, as this type decorative body, there has been proposed a decorative body (linear luminous body) provided for emitting linear light and formed to have a tubular clad, a core having a refractive index higher than that of the clad, and a reflecting layer provided between the clad and the core (JP-A-2000-338330). In the proposed linear luminous body, high-luminance light transmitted through the core is reflected as high-directivity light by a reflecting surface, so that high-luminance linear light can be obtained. The proposed linear luminous body is however constituted by only a combination of a light guide and a reflecting surface. Accordingly, the strength of the proposed linear luminous body is so low that the proposed linear luminous body cannot be used for the application requiring strength of not lower than a predetermined value.
[0007] On the other hand, there is also known a decorative body using a color-painted wire, a wire coated with a colored resin, or the like. For example, the decorative body is used as a partition in a showroom, a restaurant or the like or for decorating a handrail or the like because the decorative body is excellent in strength. When effective decoration needs to be made by use of the decorative body, it is however necessary to illuminate the decorative body from the outside additionally, that is, it is necessary to provide an external light source. Accordingly, the application of the decorative body is limited as a matter of course. In addition, it cannot be said that the decorating effect of the decorative body is high because the decorative body is only colored by receiving light emitted from the external light source.
[0008] As another linear decorative body, there has been proposed a decorative body having light-emitting diodes (LEDs) disposed linearly and sealed with a transparent resin such as silicone. This configuration, however, lacks design characteristic or decorativeness because light is observed as spots. In addition, the strength of the decorative body is so low that the application of the decorative body is limited.
SUMMARY OF THE INVENTION
[0009] The invention is developed in consideration of the problem and an object of the invention is to provide a linear luminous body high in decorativeness and excellent in strength.
[0010] Further, another object of the invention is to provide a linear luminous structure improved in the degree of freedom for design and having high decorativeness.
[0011] To achieve the foregoing object, the invention provides the following configuration.
[0012] (1) A linear luminous body comprising:
[0013] a light source;
[0014] a light source accommodating portion in which the light source is accommodated; and
[0015] a light guide held by the light source accommodating portion so as to extend from the light source accommodating portion;
[0016] wherein a light emitted from the light source is introduced into said light guide through an end surface of said light guide.
[0017] Further, the linear luminous body may further include a linear core made of a member selected from the group consisting of a metal, an alloy and a synthetic fiber; a light guide with which a side circumferential surface of the linear core is covered.
[0018] According to this configuration, the core made of a metal, or the like, is provided in the light guide, so that sufficient strength can be attained. On the other hand, the light source for introducing light into the light guide is provided, so that the linear luminous body can be decorated with light emitted from the side circumferential surface of the light guide. That is, the linear luminous body which is a decorative member can be decorated with light (direct light) emitted from the linear luminous body per se, so that an excellent decorative effect can be obtained.
[0019] Another aspect of the invention is configured as follows.
[0020] (2) A linear luminous structure comprising:
[0021] a plurality of light sources;
[0022] at least one of light source accommodating portion in each of which at least one of the plurality light sources is accommodated; and
[0023] a plurality of light guides held by the light source accommodating portions so as to extend from the light source accommodating portions;
[0024] wherein a light emitted from the light sources is introduced into said light guides through at least one end surface of each light guide, and
[0025] the light guides are connected to one another through the light source accommodating portions.
[0026] Preferably, in the above construction, the linear luminous structure may incorporate at least one connector, each of which includes at least two connection portions for holing the light guides and a body portion that constitutes said light source accommodating portion in which at least one of the light sources corresponding to a number of said connection portions are accommodated, whereby the connector connects at least two light guides to one another.
[0027] Alternatively, in the above construction, the linear luminous structure may incorporate the a plurality of connectors and at least one junction block having connector attachment surfaces,
[0028] wherein each of the plurality of connectors is provided with one connection portion for holding the light guide and a body portion in which the light source is accommodated as the light source accommodating portion, and
[0029] the connectors are fixed to the joint block at the connector attachment surfaces, so that at least two light guides are connected to one another.
[0030] According to the above configurations, the light guides are connected to one another easily so that structures of various shapes can be obtained. On the other hand, light sources are provided in body portions of the connectors so that the light guides can be made luminous when light is introduced into the light guides. That is, the structure having a framework made from the light guides can be made luminous by itself, so that an excellent decorative effect can be obtained.
[0031] Respective members (respective elements) of the invention will be described below.
[0000] (Linear Core)
[0032] The linear core is made of a member selected from the group consisting of a metal, an alloy and a synthetic fiber. For example, iron, copper, silver, stainless steel or brass can be used as the metal or alloy. For example, nylon, vinylon, polyethylene, polypropylene, aromatic polyamide fiber, aramid fiber or carbon fiber can be used as the synthetic fiber.
[0033] Preferably, a material excellent in strength and durability is used as the material of the linear core. From this point of view, stainless steel or nylon can be used as an example of the preferred material.
[0034] The material of the linear core may be selected in consideration of design characteristic. That is, the linear luminous body according to the invention is typically formed so that the linear core is observed from the outside through the light guide when light is not emitted, and a surface of the linear core is observed as specific design by receiving light when light is emitted. Accordingly, the design of the linear core forms part of the decorativeness of the linear luminous body according to the invention. In other words, the design of the linear luminous body varies according to variation in the design of the linear core per se. Specifically, when a metal or alloy is selected as the material of the linear core, the surface of the linear core is observed as a metallic tone. As a result, the linear luminous body is formed so as to be partially observed as a metallic tone. Incidentally, a half mirror treatment or the like may be applied to the surface of the light guide so that the internal structure (i.e., the surface of the linear core) cannot be observed when light is not emitted. In this case, the surface of the linear core basically has no influence on the decorativeness of the linear luminous body.
[0035] To obtain higher strength, the linear core may be preferably provided as a multi-core structure. That is, the linear core may be preferably made of a rope-like structure twisted from a plurality of wire-like members.
[0036] The surface of the linear core may be colored or plated or may be coated with vinyl chloride or the like. When the linear core is shaped like a rope as described above, coloring or the like may be applied to surfaces of the wire-like members forming the linear core.
[0037] A light-reflective layer (light-reflecting layer) may be formed on a side circumferential surface of the linear core. In this configuration, the light-reflecting layer is interposed between the linear core and the light guide, so that reflection of light in the surface of the linear core can be made efficiently. As a result, the amount of a light-scattering material or the like contained in the light guide with which the linear core is covered can be reduced or dispensed with according to circumstances. On the other hand, when the light-reflecting layer is formed so as to reflect the shape of the linear core (e.g., a twisted spiral shape, a bundle shape of fibers bundled in parallel, etc.), reflected light can be obtained according to the shape of the linear core, so that light emission excellent in design characteristic can be obtained. In addition, because a good light guiding function is obtained on the basis of efficient reflection of light due to the light-reflecting layer, light of the light source can travel to a farther place and, at the same time, luminance of light emitted from a side circumferential surface of the light guide can be uniformized more greatly. Incidentally, for example, the light-reflective layer can be formed by white painting or by vapor deposition of a high-reflectance metal such as aluminum or silver.
[0038] The diameter of the linear core is not particularly limited. For example, the diameter of the linear core is selected to be in a range of from about 0.1 mm to about 30 mm, preferably in a range of from about 0.5 mm to about 20 mm, more preferably in a range of from about 1 mm to about 10 mm. Incidentally, if the diameter of the linear core is too small, there is fear that sufficient strength cannot be obtained. If the diameter of the linear core is contrariwise too large, there is fear that decorativeness may be spoiled according to the application. For the selection of the diameter of the linear core, the material used, required strength, and/or the application of the invention can be considered.
[0039] The arrangement form of the linear core in the linear luminous body according to the invention is not particularly limited. For example, the linear core can be arranged so as to form a center axis of the linear luminous body. According to this arrangement form, the linear luminous body can be formed so as to be rotationally symmetrical with respect to the linear core as an axis of symmetry, so that it is particularly preferred in use for general purposes.
[0040] The linear core may be provided as a multi-core structure. In the multi-core structure, strength can be heightened more greatly. In addition, because the linear core can contribute to decorativeness in the linear luminous body according to the invention as described above, the multi-core structure may be used for achieving different kinds of decorativeness.
[0000] (Light Guide)
[0041] The light guide is provided so that the side circumferential surface of the linear core is covered with the light guide. Although it is preferable that the light guide adheres closely to the side circumferential surface of the linear core, a gap may be partially or entirely provided between the light guide and the linear core. In addition, a region not covered with the light guide may be present in the side circumferential surface of the linear core.
[0042] The material of the light guide is not particularly limited if the material is transmissible to light emitted from the light source. Preferably, the light guide is made of a transparent material (including a transparent and colorless or colored material). It is also preferable that the light guide is made of a material easy in processability and excellent in durability. For example, a light-transmissive resin such as a silicone resin, an urethane resin, a polycarbonate resin or an acrylic resin or another material such as glass can be used as the material of the light guide. The light guide may be made of a combination of two or more different materials.
[0043] Concave portions or convex portions may be formed in a surface of the light guide so that the form of emission of light from the surface of the light guide can be changed. For example, part of the surface of the light guide may be shaped like a convex lens so that light can be condensed by the lens effect of the convex lens.
[0044] A light-scattering agent may be preferably contained in the light guide. The light-scattering agent is provided for promoting diffusion of light in the light guide to thereby obtain light of more uniform luminance emitted from the surface of the light guide. For example, glass, a metal such as aluminum, a resin different in index of refraction of light from the light guide, silica, or the like, which is a material having a predetermined particle size, can be used as the light-scattering agent. The amount of the light-scattering agent contained in the light guide can be determined in consideration of the size (length) of the light guide, the target light-emitting form, etc. For example, the amount of the light-scattering agent can be selected to be in a range of from about 0.01% to about 0.05% (W/W), preferably in a range of from about 0.01% to about 0.1% (W/W) with respect to the light guide.
[0045] A coloring agent such as a pigment may be also contained in the light guide. When the coloring agent is contained, the light guide colored with the coloring agent can be observed to thereby obtain a decorative effect. As a result, decorativeness is improved particularly in the condition that light of the light source is not introduced into the light guide.
[0046] A luminous substance maybe further contained in the light guide or a layer containing a luminous substance may be formed on the surface of the light guide. The concept “luminous substance” includes a substance generating phosphorescence or fluorescence (fluorescent substance), alight storage material, and a reflective material (e.g., a high-reflectance metal such as Al, Ag or stainless steel or a metallic film). When, for example, the fluorescent substance is used, the color of light introduced into the light guide from the light source can be changed. The kind of the fluorescent substance allowed to be used is not particularly limited. The fluorescent substance used may be either organic or inorganic. The fluorescent color of the fluorescent substance is not particularly limited either. For example, a fluorescent substance having a fluorescent color selected from red, green and blue which are the three primary colors of light may be used or a fluorescent substance having a fluorescent color formed from an intermediate color between two of the three primary colors of light may be used. A plurality of fluorescent substances may be used in combination. For example, a mixture of a red fluorescent substance, a green fluorescent substance and a blue fluorescent substance may be used.
[0047] In use of the fluorescent substance, for example, a layer containing the fluorescent substance may be provided on the side circumferential surface of the light guide. The fluorescent substance-containing layer can be formed by printing or application of fluorescent substance-containing ink or paint or by sticking of a fluorescent substance-containing sheet. Alternatively, the fluorescent substance may be contained in the light guide. In this configuration, fluorescence is generated in the light guide and radiated from the side circumferential surface of the light guide. When the fluorescent substance is contained in the light guide, an organic fluorescent substance may be particularly preferably used as the fluorescent substance. This is because when the organic fluorescent substance is used, the transparency of the light guide can be kept so good that an illuminating effect with a clear sense can be obtained.
[0048] When the reflective material is contained in the light guide, a light-emitting form full of variety can be obtained so that part of the light guide that glitters with high luminance is observed.
[0049] A UV-absorbing agent (or a UV-scattering agent) may be further contained in the light guide to attain improvement in weather resistance. An organic compound such as a benzophenone compound, a salicylic acid compound or a benzotriazole compound or an inorganic compound such as zinc oxide or titanium oxide may be used suitably selectively as the UV-absorbing agent (or the UV-scattering agent). Incidentally, in the case where the fluorescent substance is contained in the light guide as described above, the amount of the excited fluorescent substance is reduced when the UV-absorbing agent is used in combination with the fluorescent substance. In this case, it is therefore preferable that the UV-absorbing agent is not used or the amount of the UV-absorbing agent used is adjusted within such a range that there is no obstacle to excitation of the fluorescent substance.
[0050] The shape of the surface of the light guide is not particularly limited. Typically, the surface of the light guide maybe shaped so that the contour of a section perpendicular to the center axis of the light guide becomes circular. Alternatively, the surface of the light guide may be shaped so that the contour of such a section becomes elliptic, triangular, square, rectangular, rhombic, trapezoidal, star-shaped or polygonal. Incidentally, the sectional shape and size of the light guide need not be uniform as a whole in the lengthwise direction of the light guide.
[0051] The light guide may be formed as a multi-layer structure. For example, the light guide may be formed as a two-layer structure made of two materials different in index of refraction of light. In this case, the two-layer structure is formed so that one layer relatively high in index of refraction of light is disposed on the inner side (i.e., on the linear core side) whereas the other layer relatively low in index of refraction of light is disposed on the outer side. In this configuration, diffusion of light in the inner layer is accelerated as well as a good light-guiding function is obtained in the inner layer on the basis of reflection in the interface between the inner layer and the outer layer. As a result, light can be delivered to a region farther from the light source and, at the same time, luminance of light radiated from the surface of the light guide can be uniformized.
[0052] A layer made of a material lower in refractive index than the material for forming the light guide may be provided between the linear core and the light guide. In this configuration, the layer serves as a barrier for confining light in the light guide, so that a good light-guiding function is obtained in the light guide. At the same time, the amount of light applied on the surface of the linear core is reduced to reduce the amount of light reflected by the surface of the linear core to thereby attain improvement in design characteristic of the linear luminous body.
[0053] For example, a linear member having the linear core and the light guide and provided for forming the linear luminous body according to the invention is produced by the following method. First, the linear core is produced in the same manner as in production of a wire or a wire rope. Then, a light guide material which is melted while adjusted so that the linear core is involved as the center of the light guide material is extruded by an extruder used for production of a resin tube or the like. Then, the light guide material is hardened by a process such as cooling. The light guide may be also formed by another method such as molding.
[0000] (Light Source)
[0054] The kind of the light source used is not particularly limited. For example, an LED, an electric bulb, a fluorescent lamp, or a cathode-ray tube can be used as the light source. Especially, an LED may be preferably used as the light source. This is because the LED is so small in size that the space for installation of the light source can be reduced to thereby reduce the size of the luminous body. Furthermore, the LED meets the demand for energy saving because electric power consumed by the LED is low. Furthermore, the LED has an advantage that the influence of the LED on members around the LED is small because the amount of heat generated in the LED is small. In addition, the LED is advantageous from the point of view of maintenance because the LED is long-lived. Furthermore, the LED has an advantage that a highly reliable luminous body can be formed because the LED is resistant to vibration and impact.
[0055] On the other hand, the LED also has an advantage that the response speed of the LED is high. Accordingly, switching on/off the LED, adjustment of luminance and changing the emitted light color (in the case where an LED capable of emitting light with two or more colors is used) can be made easily and instantaneously. When such characteristic of the LED is used, various light-emitting forms such as a light-emitting form full of variety and an unexpected light-emitting form can be generated. The type of the LED is not particularly limited. For example, various types of LEDs such as a round type LED and a chip type LED can be used. Particularly, an LED provided with a lens for obtaining directivity may be preferably used in order to make light incident onto the light guide efficiently.
[0056] The color of light emitted from the light source is not particularly limited. For example, a color such as red, green, blue or an intermediate color therebetween or white can be used. Alight source capable of emitting light with two or more colors may be used. In this configuration, the luminous body is formed so that various light-emitting forms can be achieved as well as light can be emitted with a larger number of colors. Specifically, a light source using a multi-color or full-color LED may be used as an example. A device having two built-in light-emitting elements (e.g., a red light-emitting element and a blue light-emitting element) different in emitted light color can be exemplified as the multi-color LED. A device having three built-in light-emitting elements, that is, a red light-emitting element, a green light-emitting element and a blue light-emitting element can be exemplified as the full-color LED.
[0057] A plurality of devices such as LEDs, bulbs, fluorescent lamps or cathode-ray tubes may be used for forming the light source. In this case, different kinds of devices (e.g., an LED and a bulb) or devices (e.g., a red LED and a blue LED) different in emitted light color may be used in combination.
[0058] When the light source is made of a plurality of LEDs, the LEDs are preferably disposed so that the distance between each LED and the center axis of the linear core is equalized and the distance between two adjacent LEDs is equalized with respect to the LEDs. This is because the distribution of light in the light guide is uniformized by the arrangement of the LEDs so that light little in light emission irregularity can be radiated from the surface of the light guide.
[0059] The light source is disposed so that light can be introduced into the light guide through an end surface of the light guide. For efficient introduction of light, the light source is preferably disposed in a position as near the end surface of the light guide as possible. When, for example, the linear luminous body according to the invention is shaped like a straight line so that the introduced light can be guided well in the light guide, the light source is preferably disposed so that the center axis of the linear luminous body is parallel to the optical axis of the light source.
[0060] If the amount of light emitted from the light source is insufficient or if a sufficient light-guiding function cannot be obtained, there is a possibility that the distribution of light may be uneven in the light guide. For example, the amount of light in a region far from the light source may be reduced. As a result, there is a possibility that unevenness in illuminance may occur in light radiated from the side circumferential surface of the light guide. In such a case, two or more light sources may be preferably used so that light can be introduced into the light guide through opposite end surfaces of the light guide.
[0061] The invention is has a special feature in that the luminous body is linear. The concept “linear” includes not only a straight line shape but also a partially or entirely twisted, bent or curved shape. Examples of the linear shape in the invention include a spiral shape, and a regularly bent shape in which the luminous body is bent at regular intervals.
[0062] The luminous body according to the invention can be used widely for indoor or outdoor decoration. Particularly it can be used preferably for the application requiring predetermined strength because sufficient strength can be attained by the linear core. When, for example, the linear luminous body according to the invention is used as a partition for partitioning a space or as a handrail, the space can be presented as a presentation effect of light. When, for example, the linear luminous body according to the invention is used instead of a rope in a construction site for another purpose than the simple purpose of decoration, person's attention in the surroundings can be called-to the linear luminous body by light effectively The luminous body according to the invention can be also used for various applications such as a clothes hanger, a course rope of a swimming pool, a car antenna, and a corner pole.
[0000] (Connector)
[0063] In the luminous structure of the invention, each connector includes connection portions, and a body portion having built-in light sources. Although the connector is preferably made of a resin in consideration of weight and mold ability, the material of the connector is not particularly limited. For example, rubber or a metal may be used as the material of the connector. Particularly use of a metal is effective in improving durability. In addition, when a metal high in heat conductivity is used, heat generated from the built-in light sources can be given off positively.
[0064] A material excellent both in strength and in durability may be preferably used as the material of the connector. From this point of view, stainless steel or nylon can be exemplified as a preferred example of the material. A shape memory alloy or a soft resin may be also used so that the connector can be deformed to an arbitrary shape.
[0065] One embodiment of connector in the invention includes at least two connection portions, and a body portion having built-in light sources. As the shape of the connector, there can be used any shape in a range of from a two-dimensional shape such as a straight line shape, an L shape, a T shape, an X shape or a Y shape to a three-dimensional shape constituted by a plurality of three-dimensional vectors expressed in an orthogonal coordinate system with X-, Y- and Z-axes, for example, a solid structure such as a tetrapod. The connection portions are disposed at end portions of sides of the connector respectively in the condition that the connection portions are opened toward the end portions respectively.
[0066] The body portion has built-in light sources not smaller in number than the connection portions. The light sources are fixed so as to emit light beams toward the opening sides of the connection portions respectively.
[0067] Each connection portion has a sleeve portion into which a corresponding light guide can be fitted so that the fitted light guide is retained, and a pull-off prevention portion for preventing the light guide from pulling out. The length and shape of the sleeve portion can be determined according to the strength and shape of the light guide.
[0068] When the strength of the light guide is low, the light guide is apt to be deformed. It is therefore preferable that the sleeve portion is selected to be long enough to retain the structure. It is also preferable that the shape of the inner wall of the sleeve portion is substantially analogous to the sectional shape of the light guide. When, for example, the contour of a section of the light guide is shaped like an ellipse, a triangle, a square, a rectangle, a rhombus, a trapezoid, a star, or a polygon, the shape of the inner wall of the sleeve portion in which the light guide is involved is made analogous to the sectional shape of the light guide.
[0069] Various configurations can be freely used if the structure of the stopper is of the type in which the stopper can be inserted easily and has a pull-off prevention effect. There is preferably used a slip-on type connector which is fixed in the condition that the light guide is inserted in the connection portion or a quick connector type assembly in which engagement portions are provided at an end portion of the light guide and at the connection potion respectively so that the engagement portions are engaged with and fixed to each other.
[0070] Each light source is built in the body portion of the connector so that light can be introduced into the light guide through an end surface of the light guide. To perform efficient introduction of light, it is preferable that the light guide can be deeply fitted into the connection portion so that the light source can be disposed in a position as near the end surface of the light guide as possible. When, for example, the linear luminous body according to the invention is shaped like a straight line so that the introduced light can be guided in the light guides well, each light source may be preferably disposed so that the center axis of the linear luminous body is parallel to the optical axis of the light source.
[0071] In another embodiment of connector in the invention, one connection portion and a body portion having a built-in light source are provided in each connector. An engagement portion is formed on an outer surface of the body portion. A luminous structure can be constructed by fixing one or more connectors to a joint block having at least one connector attachment surface.
[0072] As the shape of the joint block, it is not limited specifically so long as having at least one connector attachment surface on its outer surface. It is preferable that the connector attachment surfaces are disposed at vectorial angles different from one another. Typically, the joint block is formed in a substantially cubic shape or rectangular parallelpiped shape. Alternatively it may be formed in a columnar shape having a polygonal shape with a plurality of surfaces.
[0073] Further, a plurality of the joint blocks may be provided and adjacent joint blocks may be coupled to each other with a coupling member.
[0074] By fixing the connectors to the integrated joint blocks each having common shape or different shapes, various number and attachment modes of the luminous bodies can be produced so that an excellent decorative effect is obtained.
[0075] As for attachment structure between a connector to a joint block, an engagement projection may formed on a surface of the connector and the connector is fixed to the joint block by inserting the engagement projections into an attachment recess formed on a connector attachment surface. Alternatively, an engagement projection may be formed on the joint block and inserted into an attachment recess formed on the connector. Such the attachment recess may be formed in a shape of groove or hole.
[0076] The luminous body according to the invention can be used widely for indoor or outdoor decoration. Particularly because the light guides can be connected to one another by connectors of various shapes having built-in light sources, the luminous body can be used preferably for the application requiring an optical structure complex in shape and high in luminance. When, for example, a character advertisement is formed instead of a neon sign, the advertising effect of attracting public attention can be enhanced by full-color display as well as the characteristic, such as power saving and long life, of LED light sources can be used wisely.
[0077] When a three-dimensional solid structure is formed on the basis of the connectors, a complex-shape object for the purpose of decoration can be produced.
[0078] The configuration of the invention will be described below in more detail on the basis of an embodiment thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0079] FIG. 1 is a perspective view of a linear luminous body 1 according to Embodiment 1 of the invention;
[0080] FIG. 2 is a longitudinal sectional view of the linear luminous body 1 ;
[0081] FIG. 3 is a plan view showing the structure of one of light source units 30 used in the linear luminous body 1 ; and
[0082] FIG. 4 is a sectional view of a linear luminous body 2 according to Embodiment 2 of the invention;
[0083] FIGS. 5A and 5B are perspective views of a linear luminous structure 101 according to Embodiment 3 of the invention;
[0084] FIG. 6 is a longitudinal sectional view of the linear luminous structure 101 ;
[0085] FIG. 7 is a perspective view showing structures of connectors 110 used in the linear luminous structure 101 ;
[0086] FIG. 8 is an enlarged sectional view showing the structure of a connection portion 112 of a connector 110 used in the linear luminous structure 101 ;
[0087] FIGS. 9A to 9 C are typical views showing the structure of connection of a connection portion 112 in the linear luminous structure 101 ;
[0088] FIG. 10 is a longitudinal cross sectional view of the connector 210 according to Embodiment 4 of the invention;
[0089] FIGS. 11A, 11B and 11 C are front view, side view and rear view of the connector 210 , respectively;
[0090] FIGS. 12A and 12B are a plan view and a side view of the joint block 250 , respectively;
[0091] FIG. 13 is an example showing plural connectors 210 A are fixed to a single joint block 250 A according to Embodiment 4 of the invention;
[0092] FIGS. 14A and 14B show an example in which plural blocks 250 A are stacked and fixed to be an integral body; and
[0093] FIGS. 15A and 15B show an example in which a stay 260 is inserted in one of the attachment surface 253 , and the connectors 210 A are fixed to the other attachment surfaces 253 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0094] The configuration of the invention will be described below in more detail on the basis of the following embodiments.
Embodiment 1
[0095] FIG. 1 is a perspective view of a linear luminous body 1 according to an embodiment of the invention. FIG. 2 is a longitudinal sectional view showing the internal structure of the linear luminous body 1 . For example, the linear luminous body 1 is used as a partition.
[0096] Roughly, the linear luminous body 1 includes a wire rope 10 , a light guide 20 , and light source units 30 . The wire rope 10 is braided from a plurality of wires made of stainless steel. The wire rope 10 has a diameter of about 2 mm and a total length of about 2 m. Hooks 11 are formed at upper and lower ends of the wire rope 10 respectively so that the hooks 11 are used for installation of the linear luminous body 1 .
[0097] The wire rope 10 except its upper and lower end portions is covered with the light guide 20 so that the wire rope 10 passes through the center of the light guide 20 . The light guide 20 is a columnar member made of a silicone resin containing silica as a light-diffusing agent. The light source units 30 are disposed at opposite ends of the light guide 20 respectively. Each of the light source units 30 has four built-in LEDs 31 . In this embodiment, a full-color LED having three built-in light-emitting elements, that is, a red light-emitting element, a green light-emitting element and a blue light-emitting element, is used as each LED 31 . As shown in FIG. 3 , the four LEDs 31 in each light source unit 30 are disposed so that the distance between each LED 31 and the center of the light source unit 30 is equalized and line segments connecting the LEDs 31 to one another form a virtual square. Incidentally, FIG. 3 is a plan view of the light source unit 30 from the light-radiating side (i.e., the light guide side). Thus the light source unit 30 is configured so that the LEDs 31 are accommodated in a housing (light source accommodating portion) 30 a.
[0098] Electric power is supplied to the respective LEDs 31 through a wiring pattern formed on a surface of a board 32 and a power supply line 35 . The light source units 30 are connected to a controller (not shown) by a control line (not shown) so that the lighting state of the light source units 30 is controlled by the controller. Incidentally, elements (not shown) such as protective resistors are disposed on the boards 32 respectively.
[0099] The linear luminous body 1 is produced as follows. First, a wire rope 10 of stainless steel is produced by an ordinary method. Then, a light guide 20 is formed of a silicone resin containing a light-diffusing agent by use of an extruder so that the wire rope 10 is involved as the center of the light guide 20 . Then, two light source units 30 prepared separately are disposed and fixed so that upper and lower end surfaces of the light guide 20 are covered with the two light source units 30 respectively. Finally, upper and lower ends of the wire rope 10 are fastened with retaining rings 15 to form hooks 11 respectively.
[0100] The light-emitting form of the linear luminous body 1 will be described below. First, light beams radiated from the light source units 30 are introduced into the light guide 20 through end surfaces of the light guide 20 facing the light source units 30 respectively. The introduced light beams are guided by the light guide 20 and finally radiated from the side circumferential surface of the light guide 20 to the outside. As a result, the side circumferential surface of the light guide 20 emits light, so that linear light is observed. The color of light radiated from each light source unit 30 may be controlled so that light with various colors can be obtained. The color of light may be also changed continuously or stepwise. On the other hand, the lighting state of each LED 31 may be controlled so that various light-emitting forms such as an intermittent light-emitting form and a light-emitting form with gradually increasing or decreasing luminance can be generated. In this manner, the linear luminous body 1 can provide various presentation effects of light, so that a high decorative effect can be obtained. In addition, because the strong wire rope is involved in the light guide, the linear luminous body 1 has excellent strength and can be used for various applications.
Embodiment 2
[0101] Another embodiment of the invention will be described below with reference to FIG. 4 . FIG. 4 is a sectional view of a linear luminous body 2 according to this embodiment. Incidentally, parts the same as those in the previous embodiment are denoted by the same reference numerals as those in the previous embodiment and the description of the parts will be omitted.
[0102] In the linear luminous body 2 , a light-reflective layer (light-reflecting film) 16 is formed on a surface of the wire rope 10 . The light-reflecting film 16 is formed to have a nearly uniform thickness on the whole. Accordingly, the surface shape of the light-reflecting film 16 reflects the surface shape of the wire rope 10 . On the other hand, a light guide 25 is a columnar member made of a silicone resin. Incidentally, the light guide 25 does not particularly contain any light-diffusing agent as an additive.
[0103] The linear luminous body 2 is produced as follows. First, a wire rope 10 of stainless steel is produced by an ordinary method. Then, a surface of the wire rope 10 is painted with white ink. Then, a light guide 25 is formed of a silicone resin by use of an extruder so that the wire rope 10 processed in this manner is involved as the center of the light guide 25 . Then, upper and lower ends of the wire rope 10 are fastened with retaining rings 15 to form hooks 11 respectively. Finally, two light source units 30 prepared separately are disposed and fixed so that upper and lower end surfaces of the light guide 25 are covered with the two light source units 30 respectively. Incidentally, the linear light guide 2 to which the light source units 30 have been not attached yet and the light source units 30 may be prepared so that the light source units will be attached to the linear light guide 2 on an installation site.
[0104] In the linear light guide 2 configured as described above, light beams emitted from the light source units 30 are reflected by the light-reflecting film 16 on the surface of the wire rope 10 in a process in which the light beams are guided in the light guide. Accordingly, diffusion of light in the light guide 25 is accelerated, so that a good light-guiding function can be obtained. As a result, the side circumferential surface of the light guide 25 emits light with nearly uniform luminance, so that linear light is observed.
Embodiment 3
[0105] Next, a luminous structure of the invention as Embodiment 3 will be described below with reference to FIGS. 5A through 9C .
[0106] FIG. 5A is a perspective view of a basic structure of a linear luminous structure 101 according to an embodiment of the invention. FIG. 5B is a view showing an example of the linear luminous structure 101 having light guides combined on a plane so as shaped like a cross in the square, forming a Chinese character. FIG. 6 is a longitudinal sectional view showing the internal structure of the linear luminous structure 101 . For example, the linear luminous structure 101 is used as a character advertisement.
[0107] Roughly, the linear luminous structure 101 includes connectors 110 served as light source accommodating portion, light source units 120 , and light guides 130 . The connectors 110 can be shaped variously according to the combination of line segments. That is, the connectors 110 having various shapes such as a straight line shape, an L shape, a T shape, an X shape and a Y shape as shown in FIG. 7 can be combined freely. Incidentally, FIG. 7 is a perspective view of the connectors 110 . Each of the connectors 110 includes a body portion 111 formed on the center side of a line segment, and connection portions 112 formed at end portions of the line segment. The body portion 111 has built-in light sources 120 . Each of the connection portions 112 has a cylindrical sleeve portion 113 into which a corresponding light guide 139 is fitted and retained, and a pull-off prevention portion 114 for preventing the fitted light guide 130 from pulling out.
[0108] Each of the light source units 120 has built-in LEDs 121 of the number corresponding to the number of connection portions 112 in the connector 110 . In this embodiment, an LED having a built-in blue light-emitting element is used as each of the LEDs 121 . As shown in FIG. 6 , the LEDs 121 in each light source unit 120 are disposed so that light beams are radiated from the body portion 111 as the center of the connector 110 toward the connection portions 112 respectively.
[0109] Electric power is supplied to each LED 21 through a wiring pattern formed on a surface of a board (not shown) or through a power supply line (not shown). The light source units 120 are connected to a controller (not shown) by a control line (not shown) so that the lighting state of each light source unit 120 can be controlled by the controller. Incidentally, elements (not shown) such as a protective resistor are disposed on the board (not shown).
[0110] Each of the light guides 130 is a columnar member made of a silicone resin containing silica as a light-diffusing agent.
[0111] The linear luminous structure 101 is produced as follows. First, one end of a light guide 130 cut or curved according to a design is fitted into a connection portion 112 of one connector 110 . The other end of the light guide 130 is also fitted into a connection portion 112 of another connector 110 . In this manner, a structure can be formed two-dimensionally or three-dimensionally according to the combination of the shapes of connectors 110 and the shapes of light guides 130 .
[0112] Next, the structure of connection between a connector 110 and a light guide 130 will be described with reference to FIG. 8 and FIGS. 9A to 9 C. FIG. 8 is an enlarged sectional view of a connection portion 112 of a connector 110 . FIGS. 9A to 9 C are views showing forms of connection between a light guide 130 and a connection portion 112 .
[0113] As shown in FIG. 8 , the connection portion 112 has a sleeve portion 113 for retaining the light guide 130 , and a pull-off prevention portion 114 provided at an end portion of the connection portion 112 . The pull-off prevention portion 114 has a stopper 115 engaged with the light guide 130 when the light guide 130 is fitted into the sleeve portion 113 , and a piston ring 116 for enlarging the diameter of the stopper 115 to disengage the light guide 130 from the stopper 115 when the light guide 130 needs to be attached/detached.
[0114] FIG. 9A is a view showing a state in which the light guide 130 is fitted into the connection portion 112 . When the light guide 130 is fitted into an opening formed in the piston ring 116 , the light guide 130 abuts on a pawl 117 of the stopper 115 and gets locked. The paw 117 is tapered toward the opening side. Accordingly, when the light guide 130 is forced into the opening, the diameter of the stopper 115 is enlarged so that the light guide 130 can be fitted into the opening. As shown in FIG. 9B , when the piston ring 116 is pushed toward the connector 110 , the diameter of the stopper 115 is enlarged because a front end portion of the piston ring 116 and the pawl 117 of the stopper 115 are tapered to each other. As a result, the light guide 130 can be fitted into the connection portion 112 without resistance. As shown in FIG. 9C , when the piston ring 116 is released in the condition that the light guide 130 is fitted into the connection portion 112 till the light guide 130 abuts on the pawl 117 of the stopper 115 , the pawl 117 is engaged with the light guide 130 to prevent the light guide 130 from pulling out. In this manner, the sleeve portion 113 retains the light guide 130 .
[0115] When the light guide 130 needs to be removed from the connector 110 , the piston ring 116 is pushed toward the connector 110 in the same manner as in the case where the light guide 130 needs to be fitted into the connector 110 as shown in FIG. 9B . As a result, the light guide 130 is disengaged from the pawl 117 , so that the light guide 130 can be removed.
[0116] Next, the light-emitting form of the linear luminous structure 101 will be described. First, light beams emitted from the built-in light source unit 120 of each connector 110 are introduced into corresponding light guides 130 through end surfaces of the light guides 130 facing the light source unit 120 respectively. The introduced light beams are guided by the light guides 130 and finally radiated to the outside from the side circumferential surfaces of the light guides 130 respectively. As a result, the side circumferential surfaces of the light guides 130 are made luminous, so that linear light is observed. The color of light emitted from each light source unit 120 may be controlled so that light with various colors can be obtained. The color of light may be also changed continuously or stepwise. When different colors of light, e.g., blue and red, are introduced into a light guide 130 through opposite ends of the light guide 130 , the resulting color of light can be changed gradually from blue to violet or red, so that a gradation effect can be presented. On the other hand, the lighting state of each LED 121 may be controlled so that various light-emitting forms such as an intermittent light-emitting form and a light-emitting form with gradually increasing or decreasing luminance can be generated. In this manner, the linear luminous structure 101 can provide various presentation effects of light, so that a high decorative effect can be obtained.
Embodiment 4
[0117] Next, a luminous structure of the invention as Embodiment 4 will be described below with reference to FIGS. 10 through 14 B.
[0118] FIGS. 10 through 12 B show a luminous structure of the embodiment constituted by a connector 210 and a joint block 250 . FIG. 10 is a longitudinal cross sectional view of the connector 210 . FIGS. 11A, 11B and 11 C are front view, side view and rear view of the connector 210 .
[0119] As shown in FIGS. 10, 11A , 11 B and 11 C, the connector 210 , which is served as a light source accommodating portion, is provided with a body portion 213 in which a light source unit 220 is accommodated and a connection portion 214 for connecting and holding a light guide as described in the foregoing embodiments.
[0120] An opening 221 through which the light source unit 220 is inserted into the body portion 213 , is formed on a side surface of the body portion 213 . When the light source unit 220 is mounted in the body portion 213 , the opening 221 is closed with the lid member 222 . In the lid member 222 , a through hole 223 is formed for extending a lead wire (not shown) electrically connected to the light source unit to the outside. The connection portion 214 is attached to a front face of the body portion 213 . The connection portion 214 includes a pull of prevention portion provided with an annular stopper 215 fitted to a front opening 213 a formed on the front face of the connector 210 , a piston ring 216 formed like a flange which is fitted to the stopper 215 and holds the light guide with an inner peripheral surface thereof. In this embodiment, a retaining pawl 217 is formed on a connector-side end of the piston ring 216 . The connection portion 214 is configured so that the retaining pawl 217 is engaged with an inner surface of the stopper 215 when the piston ring 216 is pressed to the connector side, thereby preventing the piston ring 216 from pulling off while holding the light guide.
[0121] An engagement projection 218 is formed on a rear surface 213 b of the body portion 213 . As shown in FIGS. 11A through 11C , the engagement projection 218 is formed across opposite side faces of the body portion 213 on the rear surface 213 b , having a narrow proximal portion 218 a and a wide distal portion 218 b.
[0122] FIGS. 12A and 12B are a plan view and a side view of the joint block 250 , respectively. As shown FIGS. 12A and 12B , the joint block has an outer shape substantially of rectangular column, having a circular hole as a center axis and side surfaces served as connector attachment surfaces. On each side surface, an attachment recess 252 is formed so as to be in parallel with the axis. The attachment recess 252 is provided with a narrow communication portion 252 a on the surface and a rectangular groove 252 b having a wide bottom. When the connector 210 .is fixed to the joint block 250 , the narrow proximal portion 218 a of the engagement projection 218 is inserted into the narrow communication portion 252 a , and the wide distal portion 218 b of the engagement projection 218 is inserted into the rectangular groove 252 b , whereby the engagement projection 218 is fitted to the attachment recess 252 . Since the attachment recess 252 is formed across opposite faces of the joint block 250 , the engagement projection 218 can be inserted along the axial direction of the joint block 250 from one side face to the opposite one.
[0123] Next, another example in which connectors 210 A are fixed to a joint block or plural blocks 250 A, will be described below. Incidentally, although shapes of the engagement projection and the attachment recess in this example are different from those of the above-described connector 210 and joint block 250 , basic structures are similar so that the connector 210 A and the joint block 250 A can be handled in the same manner for fixing operation.
[0124] FIG. 13 is an example showing plural connectors 210 A are fixed to a single joint block 250 A. That is, four connectors 210 A are fixed to all the connector attachment surfaces 253 on the joint block 250 A, respectively. Thus in this embodiments, the plural connectors 210 A can be selectively fixed to the joint block 250 A as desired.
[0125] On the other hand, FIGS. 14A and 14B show an example in which plural blocks are stacked and fixed to be an integral body. As shown in FIG. 14A , one connector 210 A is fixed to one of the attachment surfaces 253 in each joint block 250 A.
[0126] Stays 260 with a length are inserted in the attachment recesses 252 A formed on two opposite attachment surfaces adjacent to the attachment surface 253 to which the connector 210 A is fixed. The stays 260 are served as a coupling member coupling the plural joint blocks 250 A which are stacked to one another, by commonly inserted into the attachment recesses 252 A in the stacked joint blocks 250 A as shown in FIG. 14B .
[0127] Similarly, FIGS. 15A and 15B show an example in which a stay is inserted in one of the attachment surface 253 , and the connectors 210 A are fixed to the other attachment surfaces 253 .
[0128] In the above examples, the connectors 210 A and joint blocks 250 A are described as having the same shape. However, the invention is not limited this feature. Various shapes of joint blocks may be coupled to one another in combination and connectors having various shapes or illumination modes may be fixed to a single joint block.
[0129] Further although the joint blocks are stacked in the axial direction of those joint blocks in the above examples, the joint blocks may be coupled so that the attachment surfaces of the adjacent joint blocks are opposed and abutted to each other.
[0130] As described above, luminous structures can be formed by holding light guides with the connectors fixed to the joint blocks. By illuminating the light source units as a desired mode, an excellent decorative effect can be accomplished. Further, more complicated illumination effect can be presented by combining plural joint blocks.
[0131] The invention is not limited to the description of the above embodiments. Various modifications that can be easily conceived by those skilled in the art may be included in the invention without departing from the scope of claim for a patent.
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The invention is directed to a linear luminous body comprising: a light source; a light source accommodating portion in which the light source is accommodated; and a light guide held by the light source accommodating portion so as to extend from the light source accommodating portion; wherein a light emitted from the light source is introduced into said light guide through an end surface of said light guide.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/174,825, filed May 1, 2009 and entitled “Casing Bits, Drilling Assemblies, and Methods for Use In Forming Wellbores With Expandable Casing,” the disclosure of which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] Embodiments of the present invention relate to casing bits, drilling assemblies, and methods that may be used to form wellbores using expandable casing.
BACKGROUND
[0003] Wellbores are formed in subterranean formations for various purposes including, for example, extraction of oil and gas from the subterranean formation and extraction of geothermal heat from the subterranean formation. A wellbore may be formed in a subterranean formation using a drill bit such as, for example, an earth-boring rotary drill bit. Different types of earth-boring rotary drill bits are known in the art including, for example, fixed-cutter bits (which are often referred to in the art as “drag” bits), rolling-cutter bits (which are often referred to in the art as “rock” bits), diamond-impregnated bits, and hybrid bits (which may include, for example, both fixed cutters and rolling cutters). The drill bit is rotated and advanced into the subterranean formation. As the drill bit rotates, the cutters or abrasive structures thereof cut, crush, shear, and/or abrade away the formation material to form the wellbore. A diameter of the wellbore drilled by the drill bit may be defined by the cutting structures disposed at the largest outer diameter of the drill bit.
[0004] The drill bit is coupled, either directly or indirectly, to an end of what is referred to in the art as a “drill string,” which comprises a series of elongated tubular segments connected end-to-end that extends into the wellbore from the surface of the formation. Various tools and components, including the drill bit, may be coupled together at the distal end of the drill string at the bottom of the wellbore being drilled. This assembly of tools and components is referred to in the art as a “bottom hole assembly” (BHA).
[0005] The drill bit may be rotated within the wellbore by rotating the drill string from the surface of the formation, or the drill bit may be rotated by coupling the drill bit to a downhole motor, which is also coupled to the drill string and disposed proximate the bottom of the wellbore. The downhole motor may comprise, for example, a hydraulic Moineau-type motor having a shaft, to which the drill bit is mounted, that may be caused to rotate by pumping fluid (e.g., drilling mud or fluid) from the surface of the formation down through the center of the drill string, through the hydraulic motor, out from nozzles in the drill bit, and back up to the surface of the formation through the annular space between the outer surface of the drill string and the exposed surface of the formation within the wellbore.
[0006] It is known in the art to use what are referred to in the art as a “reamer” devices (also referred to in the art as “hole opening devices” or “hole openers”) in conjunction with a drill bit as part of a bottom hole assembly when drilling a wellbore in a subterranean formation. In such a configuration, the drill bit operates as a “pilot” bit to form a pilot bore in the subterranean formation. As the drill bit and bottom hole assembly advances into the formation, the reamer device follows the drill bit through the pilot bore and enlarges the diameter of, or “reams,” the pilot bore.
[0007] After drilling a wellbore in a subterranean earth-formation, it may be desirable to line the wellbore with sections of casing or liner. Casing is relatively large diameter pipe (relative to the diameter of the drill pipe of the drill string used to drill a particular wellbore) that is assembled by coupling casing sections in an end-to-end configuration. Casing is inserted into a previously drilled wellbore, and is used to seal the walls of the subterranean formations within the wellbore. The casing then may be perforated at one or more selected locations within the wellbore to provide fluid communication between the subterranean formation and the interior of the wellbore. Casing may be cemented in place within the wellbore. The term “liner” refers to casing that does not extend to the top of a wellbore, but instead is anchored or suspended from inside the bottom of another casing string or section previously placed within the wellbore. As used herein, the terms “casing” and “casing string” each include both casing and liner, and strings respectively comprising sections of casing and liner.
[0008] As casing is advanced into a wellbore, it is known in the art to secure a cap structure to the distal end of the distal casing section in the casing string (the leading end of the casing string as it is advanced into the wellbore). As used herein, the term “distal” means distal to the earth surface into which the wellbore extends (i.e., the end of the wellbore at the surface), while the term “proximal” means proximal to the earth surface into which the wellbore extends. The casing string, with the casing bit attached thereto, optionally may be rotated as the casing is advanced into the wellbore. In some instances, the cap structure may be configured as what is referred to in the art as a casing “shoe”, which is primarily configured to guide the casing into the wellbore and ensure that no obstructions or debris are in the path of the casing, and to ensure that no debris is allowed to enter the interior of the casing as the casing is advanced into the wellbore. The “shoe” may conventionally contain a check valve, termed a “float valve,” to prevent fluid in the wellbore from entering the casing from the bottom, yet permit cement to be subsequently pumped down into the casing, out the bottom through the shoe, and into the wellbore annulus to cement the casing in the wellbore.
[0009] In other instances, the casing cap structure may be configured as a reaming bit or “shoe,” which serves the same purposes of a casing shoe, but is further configured for reaming (i.e., enlarging) the diameter of an existing wellbore as the casing is advanced into the wellbore. It is also known to employ drill bits configured to be secured to the distal end of a casing string for drilling a wellbore. Drilling a wellbore with such a drill bit attached to casing is referred to in the art as “drilling with casing.” Such reaming bits or shoes, as well as such drill bits, may be configured and employ materials in their structures to enable subsequent drilling therethrough from within using a drill bit run down the casing or liner string. As used herein, the term “casing bit” means and includes such casing bits as well as such reaming bits and shoes configured for attachment to a distal end of casing as the casing is advanced into a wellbore.
BRIEF SUMMARY
[0010] In some embodiments, the present invention includes casing bits having a body and at least one cutting structure on an outer surface of the body. The casing bits further include an expander at least partially disposed within the body. The expander is sized and configured to expand expandable casing to which the casing bit is secured as the expander is forced longitudinally through the expandable casing.
[0011] In additional embodiments, the present invention includes drilling assemblies having a casing bit attached to an end of at least one section of expandable casing. The casing bit has a body and at least one cutting structure on an outer surface of the body. An expander is disposed within at least one of the casing bit and the end of the section of expandable casing. The expander is sized and configured to expand expandable casing as the expander is forced longitudinally through the expandable casing.
[0012] In additional embodiments, the present invention includes methods of forming casing bits. To form a casing bit, an expander may be configured to enlarge at least an inner diameter of expandable casing as the expander is forced through the expandable casing, and the expander may be positioned at least partially within a body of the casing bit.
[0013] In additional embodiments, the present invention includes methods of forming drilling assemblies. In accordance with such methods, an expander may be positioned within at least one of a body of a casing bit and an adjacent end of a section of expandable casing, and the body of the casing bit may be attached to the end of the section of expandable casing. The expander may be configured to enlarge at least an inner diameter of expandable casing as the expander is forced through the expandable casing.
[0014] Yet further embodiments of the present invention include methods of casing a wellbore. A wellbore may be drilled and/or reamed using a casing bit attached to a distal end of at least one section of expandable casing. An expander disposed within at least one of the casing bit and the distal end of the section of expandable casing may be forced longitudinally through the section of expandable casing in a proximal direction. As the expander is forced through the expandable casing, at least an inner diameter of the expandable casing may be enlarged.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIGS. 1A through 1F are simplified, schematic cross-sectional views of a wellbore and equipment therein illustrating a method that may be used to drill a wellbore using a casing bit on expandable casing, and subsequently expanding the expandable casing within the wellbore;
[0016] FIG. 2 is a simplified cross-sectional view of an embodiment of a casing bit of the present invention;
[0017] FIG. 3 is a simplified cross-sectional view of another embodiment of a casing bit of the present invention;
[0018] FIG. 4 is a side view of an embodiment of an outer body of a casing bit of the present invention; and
[0019] FIG. 5 is a side view of another embodiment of an outer body of a casing bit of the present invention.
DETAILED DESCRIPTION
[0020] The illustrations presented herein are not actual views of any particular drilling system, drilling tool assembly, or component of such an assembly, but are merely idealized representations which are employed to describe the present invention.
[0021] Embodiments of the present invention may be used to drill or ream a wellbore with expandable casing using a casing bit attached to the expandable casing, and to subsequently expand (i.e., enlarge at least an inner diameter of) the expandable casing without tripping the casing bit out from the wellbore.
[0022] An embodiment of a method of the present invention that may be used to form or enlarge at least a section of a wellbore and position casing within the section of the wellbore is described below with reference to FIGS. 1A through 1F .
[0023] Referring to FIG. 1A , a drilling assembly may be provided that includes a casing bit 10 attached to a distal end 12 of expandable casing 14 . The expandable casing 14 with the casing bit 10 thereon may be advanced into a previously drilled wellbore 16 . As discussed in further detail below with reference to FIG. 4 , the casing bit 10 may comprise one or more cutting structures configured for at least one of reaming and drilling a wellbore 16 . The cutting structure or structures may comprise any conventional abrasive or superabrasive material suitable for removing material from the particular formation being reamed or drilled. In some embodiments, at least a portion of the wellbore 16 may have been lined with additional casing 18 prior to advancing the expandable casing 14 into the wellbore 16 . The expandable casing 14 may be advanced into the wellbore 16 until the casing bit 10 is positioned at the bottom of the previously drilled section of the wellbore 16 . The expandable casing 14 and the casing bit 10 attached to the distal end 12 of the expandable casing 14 then may be rotated within the wellbore 16 as axial force, termed “weight on bit” (WOB), is applied to the expandable casing 14 and the casing bit 10 to cause the casing bit 10 to drill an additional section 20 of the wellbore 16 into the subterranean formation 22 .
[0024] The drilling assembly may be rotated within the wellbore 16 by rotating the expandable casing 14 from the surface of the formation, or the drilling assembly may be rotated by coupling the expandable casing 14 to a downhole motor. The motor also may be coupled to a drill string and disposed within the wellbore 16 . The downhole motor may comprise, for example, a hydraulic Moineau-type motor having a shaft, to which the expandable casing 14 is attached. The drive shaft and the expandable casing 14 may be caused to rotate by pumping fluid (e.g., drilling mud or fluid) from the surface of the formation down through the center of the drill string, through the hydraulic motor, through the expandable casing 14 , through the casing bit 10 , out through fluid passageways extending through the casing bit, and back up to the surface of the formation through the annular space between the outer surface of the expandable casing 14 and the exposed surface of the formation within the wellbore 16 .
[0025] With continued reference to FIG. 1A , the drilling assembly further includes an expander 24 that may be disposed within and attached to at least one of the casing bit 10 and the expandable casing 14 at a location proximate the distal end 12 of the expandable casing 14 . The expander 24 is sized and configured to expand the diameter of the expandable casing 14 as the expander 24 is forced longitudinally through the interior of the expandable casing 14 . By way of example and not limitation, the expander 24 may be a generally cylindrical, tubular member. A fluid passageway may extend longitudinally through the length of the expander 24 . A tapered, frustoconical surface may be provided on a proximal end of the expander 24 to facilitate the smooth, gradual expansion of the expandable casing 14 as the expander 24 is forced through the casing 14 . The expander 24 may comprise, for example, a metal alloy exhibiting a yield strength sufficiently high that the expander 24 will not undergo any significant plastic deformation, and sufficiently low elastic deformation to allow complete expansion of the expandable casing 14 , as the expander 24 is forced longitudinally through the expandable casing 14 .
[0026] In some embodiments, the expander 24 initially may be partially disposed within an interior region of the casing bit 10 , and partially within an interior region of the distal end 12 of the expandable casing 14 . In additional embodiments, the expander 24 initially may be entirely disposed within an interior region of the casing bit 10 , or entirely within an interior region of the distal end 12 of the expandable casing 14 .
[0027] The expandable casing 14 may comprise a metal alloy having a material composition selected to allow the expandable casing 14 to expand plastically as the expander 24 is forced therethrough. The ultimate strength of the material of the expandable casing 14 should be sufficiently high to prevent the expandable casing 14 from rupturing as the expander 24 is forced through the expandable casing 14 .
[0028] After drilling an additional section 20 of the wellbore 16 using the casing bit 10 , a liquid cement or other hardenable material may be pumped through the expandable casing 14 , and out from the casing bit 10 through fluid passageways 30 extending therethrough, into the annulus between the formation and the casing. The cement or other hardenable material may have a composition selected to harden only after expansion of the expandable casing 14 , as described below. The volume of cement pumped into the annulus may be selected to fill the ultimate volume of the annulus that will be present after expansion of the expandable casing 14 . Initially, when such a volume of cement is pumped into the annulus, it may not surround the casing 14 along the entire length thereof. Upon expansion of the expandable casing 14 , however, the expanding casing 14 may squeegee the cement along the length of the casing 14 to surround the expanded casing 14 along substantially the entire length thereof. The cement may be allowed to solidify within the annular space after expansion of the casing 14 , thereby affixing the expandable casing 14 in place within the wellbore 16 .
[0029] Referring to FIG. 1B , a pipeline 26 (e.g., a drill string, coiled tubing, a parasitic string, etc.) may be advanced through the interior of the expandable casing 14 and attached to the expander 24 . One or more centralizer devices 65 such as, for example, centralizer springs, may be used to position (e.g., center) the pipeline 26 within the expandable casing 14 . By way of example and not limitation, a threaded pin 28 may be provided on a proximal end of the expander 24 . The threaded pin 28 may be configured to matingly engage a threaded box on a distal end of the pipeline 26 . Thus, the pipeline 26 may be rotated to thread the distal end of the pipeline 26 onto the threaded pin 28 on the expander 24 . Of course, a threaded box may be used on a proximal end of the expander 24 , and a threaded pin on the distal end of the pipeline 26 . In additional embodiments, mechanical attachment between the pipeline 26 and the expander 24 may be obtained using other connection configurations known in the art that require little or no relative rotation between the pipeline and the expander 24 . Many such connections are known in the art and may be employed in embodiments of the present invention. Some such connections are referred to in the art as mechanical “stingers,” and include complementary male and female connection portions (one being provided on the pipeline 26 and the other on the expander 24 ) that mechanically interlock with one another upon insertion of the male connector into the female connector.
[0030] In additional embodiments of the invention, the pipeline 26 (or another type of string) may be attached to the expander 24 prior to drilling the additional section 20 of the wellbore 16 with the casing bit 10 and expandable casing 14 .
[0031] Referring to FIG. 1C , fluid passageways 30 extending through the casing bit 10 may be plugged. By way of example and not limitation, a plug 32 (e.g., an elongated body, a generally spherical ball, or a dart) may be pumped down through the pipeline 26 , through the expander 24 , and into a receptacle 34 in the casing bit 10 configured to receive the plug 32 , in the manner of a float plug engaging a float shoe. The receptacle 34 may be configured to lockingly engage, and retain therein, the plug 32 to prevent backflow into expandable casing 14 from the wellbore. The casing bit 10 may be configured such that fluid flow through the fluid passageways 30 in the casing bit 10 is interrupted when the plug 32 is disposed and seated within the receptacle 34 .
[0032] Referring to FIG. 1D , the expander 24 may be forced longitudinally through the expandable casing 14 from the distal end 12 thereof toward a proximal end 36 thereof. The expander 24 may be forced through the expandable casing 14 by pulling the expander 24 through the expandable casing 14 using the pipeline 26 (i.e., by mechanical force), by pumping hydraulic fluid down through the pipeline 26 and into a space 37 distal to the expander 24 at relatively high pressure such that the hydraulic pressure distal to the expander 24 forces the expander 24 through the expandable casing 14 in the proximal direction (i.e., by hydraulic pressure), or by a combination of such methods (i.e., by a combination of mechanical force and hydraulic pressure).
[0033] FIG. 1D illustrates the expander 24 at a relatively lower intermediate location within the expandable casing 14 . As shown in FIG. 1D , the section of the expandable casing 14 distal to the expander 24 has a relatively larger expanded inner diameter D E , while the section of the expandable casing 14 proximal to the expander 24 has a relatively smaller unexpanded inner diameter D U . In some embodiments, D E may be about 105% or more of D U . In additional embodiments, D E may be about 110% or more of D U , or even about 120% or more of D U .
[0034] As the inner diameter of the expandable casing 14 is expanded from D U to D E , the overall length of the expandable casing 14 may decrease, the wall thickness of the expandable casing 14 may decrease, or both the overall length and the wall thickness of the expandable casing 14 may decrease. Thus, a desirable final length and a desirable final wall thickness may be considered together with the degree to which the overall length and the wall thickness of the expandable casing 14 decrease upon expansion thereof by the expander 24 when designing an initial, unexpanded section of expandable casing 14 for a particular application.
[0035] FIG. 1E is similar to FIG. 1D , but illustrates the expander 24 at a relatively higher intermediate location within the expandable casing 14 .
[0036] FIG. 1F illustrates the expandable casing 14 after the expander 24 has been passed entirely through the expandable casing 14 , such that the entire length of the casing 14 has been expanded from the relatively smaller unexpanded inner diameter D U to the relatively larger expanded inner diameter D E , and the expander 24 has been removed from the wellbore 16 . Upon expansion of the proximal end 36 of the expandable casing 14 , the outer surface 38 of the expandable casing 14 at the proximal end 36 thereof may be forced against an inner surface 40 of a previously placed section of additional casing 18 . Optionally, one or more sealing materials may be provided between the outer surface 38 of the expandable casing 14 and the inner surface 40 of the additional casing 18 to ensure that an adequate seal results therebetween upon expansion of the expandable casing 14 by the expander 24 .
[0037] After expanding the expandable casing 14 and removing the expander 24 from the wellbore 16 to provide a structure like that shown in FIG. 1F , the wellbore 16 may be prepared for production by, for example, perforating the casing 14 and/or the casing 18 at one or more locations along the wellbore 16 within producing regions of the formations. In additional embodiments, an additional section of the wellbore 16 may be drilled distal to the expanded casing 14 using another drill bit to drill through the remaining portions of the casing bit 10 at the distal end of the wellbore 16 . As described in further detail below, the casing bit 10 may be configured to facilitate drilling therethrough by another drill bit. In some embodiments, another casing bit 10 and another section of expandable casing 14 having a relatively smaller outer diameter may be used to drill through the casing bit 10 shown in FIG. 1F , after which the other section of expandable casing 14 also may be expanded. This process may be repeated as desirable until the wellbore 16 reaches a desirable or limited depth.
[0038] FIG. 2 is an enlarged, simplified, cross-sectional view of an embodiment of a casing bit 10 of the present invention that may be used to position expandable casing 14 within a wellbore 16 , as previously discussed in relation to FIGS. 1A through 1F .
[0039] As shown in FIG. 2 , the casing bit 10 has an outer bit body 50 . The outer body 50 may comprise, for example, a metal alloy or a composite material having physical properties that include a strength sufficient to enable the casing bit 10 to be used for drilling, reaming, or both drilling and reaming, but that also allow the outer body 50 to be subsequently drilled through by another drill bit. A plurality of cutting structures for drilling and/or reaming may be provided on an exterior surface of the outer body 50 , as described below, although such cutting structures are not illustrated in the simplified view of FIG. 2 . By way of example and not limitation, the outer body 50 may comprise an outer body as described in U.S. patent application Ser. No. 11/747,651, which was filed May 11, 2007 and entitled “Reaming Tool Suitable For Running On Casing Or Liner And Method Of Reaming” (U.S. Patent Application Publication No. US 2007/0289782 A1, published Dec. 20, 2007), or as described in U.S. Pat. No. 7,395,882 B2, which issued on Jul. 8, 2008 to Oldham et al., each of which is incorporated herein in its entirety by this reference.
[0040] An expander 24 may be at least partially disposed within the outer body 50 . In the embodiment of FIG. 2 , the expander 24 is partially disposed within the outer body 50 , but protrudes from a proximal end of the outer body 50 . In other embodiments, the expander 24 may be substantially entirely disposed within the outer body 50 , or the expander 24 may be disposed substantially entirely outside the outer body 50 and attached to a proximal end 52 of the outer body 50 .
[0041] Optionally, the expander 24 may be attached to the outer body 50 . As a non-limiting example, one or more shear pins 54 may be used to attach the expander 24 to the outer body 50 . The shear pins 54 may extend at least partially through the outer body 50 and at least partially through the expander 24 . The shear pins 54 may be sized and configured to shear apart (i.e., fail) when a predetermined force is applied between the expander 24 and the outer body 50 in the longitudinal direction, as occurs when the expander 24 begins to be forced through expandable casing 14 ( FIGS. 1A-1F ) to which the casing bit 10 is attached. To prevent the shear pins 54 from damaging the casing 14 as the expander is forced therethrough, the shear pins 54 may comprise a relatively soft metal alloy or a polymer material, and/or the shear pins 54 may be configured to fail at a location recessed relative to the outer surface of the expander. In yet further embodiments, the shear pins 54 could be disposed at other locations and orientations such that, upon failure of the shear pins 54 , no portion of the shear pin 54 would rub against the casing 14 as the expander 24 is forced through the casing 14 . In other embodiments, a snap ring, or another type of fastener, may be disposed between the inner surface of the outer body 50 and an exterior surface of the expander 24 , and may be configured to be retained within the outer body 50 when sufficient force is applied between the expander 24 and the body 50 to longitudinally separate the same. In a broad sense, structure securing the expander 24 to the outer body 50 may be designed and configured to fail and permit release of expander 24 from the outer body responsive to at least one selected condition applied thereto. Such a condition may include, without limitation, tension, shear, torsion, compression and hydraulic pressure.
[0042] In additional embodiments, the expander 24 may not be fixedly attached to the outer body 50 , and may simply be retained in position relative to the outer body 50 upon attachment of the casing bit 10 to the expandable casing 14 due to mechanical interference between the expander 24 and the outer body 50 and between the expander 24 and the expandable casing 14 . In some embodiments, the expander 24 may be retained snugly so that the expander 24 is substantially restrained from longitudinal movement (e.g., in the distal or proximal directions). In other embodiments, the expander 24 may be retained with some amount of extra longitudinal space allowing the expander 24 to longitudinally separate from the outer body 50 to provide a net force acting on the expander 24 in the proximal longitudinal direction when a fluid is pressurized, as discussed below.
[0043] As previously described, the expander 24 may comprise a tapered, frustoconical surface 56 on a proximal end 58 of the expander 24 to facilitate the smooth, gradual expansion of the expandable casing 14 as the expander 24 is forced through the expandable casing 14 to expand the same. Furthermore, the expander 24 may comprise at least one feature 60 that may be matingly engaged by a string or pipeline (e.g., a drill string, coiled tubing, a parasitic string, a so-called “fishing string,” etc.). By way of example and not limitation, the feature 60 may comprise a threaded pin 28 provided on the proximal end 58 of the expander 24 . As previously discussed, the threaded pin 28 may be configured to matingly engage a threaded box on a distal end of a string such as, for example, a pipeline 26 . Also as previously discussed, it is contemplated that expander 24 may instead comprise a threaded box engageable by a threaded pin at a distal end of pipeline 26 by stabbing the pin into the box and rotating the pipeline. As another alternative, a stinger at the distal end of pipeline 26 may lockingly engage complementary structure of a receptacle at the proximal end of the expander 24 , such complementary structures being known to those of ordinary skill in the art.
[0044] In some embodiments, the expander 24 may comprise a fluid passageway 62 that extends longitudinally through the expander 24 . Furthermore, the expander 24 may have a shape configured to define at least one cavity 64 when the expander 24 is positioned within the casing bit 10 . The cavity 64 may be located and shaped to allow fluid to flow into the cavity 64 from the fluid passageway 62 when fluid is pumped in the distal direction down through the expander 24 through the fluid passageway 62 . The shape of the cavity 64 may be configured to provide a net force acting on the expander 24 in the proximal longitudinal direction when fluid within the fluid passageway 62 and the cavity 64 is pressurized. In some configurations of the casing bit 10 , in the absence of such a cavity 64 , such a net force might not result when the fluid passageway 62 is pressurized until at least some degree of longitudinal separation is attained between the expander 24 and the outer body 50 . The expander 24 may also include one or more fluid ports 34 that extend longitudinally through the expander 24 . These fluid ports 34 are located remote from the fluid passageway 62 , and allow for fluid communication between the spaces within the wellbore above and below the expander 24 to allow fluid above the expander 24 to flow through the expander 24 through the fluid ports 34 to the space below the expander 24 as the expander 24 is forced upward through expandable casing in the wellbore.
[0045] With continued reference to FIG. 2 , in some embodiments, the casing bit 10 may further comprise an inner body 70 . The inner body 70 may comprise a separate body from the outer body 50 . In such embodiments, the inner body 70 may comprise a material differing from a material of the outer body 50 . For example, the material of the inner body 70 may comprise a metal alloy, a polymer material, or a composite material that is relatively softer and/or of lower strength relative to the outer body 50 . The inner body 70 may not be subjected to the vigorous forces and stresses to which the outer body 50 is subjected during drilling, and, hence, it may be desirable to form the inner body 70 from a material that is relatively easier to subsequently drill through (relative to the outer body 50 ) using another drill bit.
[0046] In additional embodiments, however, the outer body 50 and the inner body 70 may simply be different regions of a common, integral (i.e., monolithic), substantially homogenous body formed of and comprising materials suitable for use as the outer body 50 .
[0047] One or more fluid passageways 30 may extend through the casing bit 10 to allow fluid to be pumped through the expander 24 and out from the casing bit 10 through the fluid passageways 30 during a drilling process. A section of each of the fluid passageways 30 may extend through the inner body 70 , and another section of each of the fluid passageways 30 may extend through the outer body 50 . Each of the fluid passageways 30 may lead to, or pass through, a receptacle 34 , as mentioned above, configured to receive a plug 32 ( FIGS. 1C-1F ) therein for plugging the fluid passageways 30 . The plug 32 also may comprise a material that is relatively easy to subsequently drill through using another drill bit, but that has physical properties sufficient to plug the fluid passageways 30 and withstand the fluid pressure differential across the plug 32 that results upon pressurization of the space 37 ( FIGS. 1D and 1E ) distal to the expander 24 but proximal to the casing bit 10 when the expander 24 is being forced through expandable casing 14 .
[0048] The casing bit 10 may be secured to a distal end 12 of a section of expandable casing 14 by, for example, welding the outer body 50 of the casing bit 10 to the distal end 12 of the expandable casing 14 . In additional embodiments, complementary threads may be formed on the casing bit 10 and the distal end 12 of the expandable casing 14 , and the casing bit 10 may be threaded to the distal end 12 of the expandable casing 14 to secure the casing bit 10 to the expandable casing 14 . In such embodiments, the interface between the casing bit 10 and the expandable casing 14 optionally may be welded to further secure the casing bit 10 to the expandable casing 14 and threading the casing bit 10 to the expandable casing 14 . Other methods such as, for example, brazing, also may be used to secure the casing bit 10 to the expandable casing 14 .
[0049] In yet additional embodiments of the present invention, the expander 24 may be disposed between (e.g., located at least substantially entirely between) the casing bit 10 and the distal end 12 of the expandable casing 14 . For example, a separate, additional sub (e.g., a generally tubular component comprising an inner cavity in which the expander 24 may be disposed) may be provided between the casing bit 10 and the distal end 12 of the expandable casing 14 , and the expander 24 may be positioned within, and optionally secured within, the separate, additional sub. Referring to FIG. 2 , the portion of the outer body 50 proximal to the dashed lines 67 shown therein may comprise a separate, additional sub in which the expander 24 may be disposed and secured. Such a separate, additional sub may be attached to the casing bit 10 at the location of the dashed lines 67 in manners like those previously described for attaching the distal end 12 of the expandable casing 14 to the casing bit 10 (e.g., one or more of welding, threading, brazing, etc.). The sub could also extend further in the proximal direction such that the expander 24 is at least substantially entirely contained within the sub.
[0050] FIG. 3 is an enlarged, simplified, cross-sectional view of another embodiment of a casing bit 10 ′ of the present invention that may be used to position expandable casing 14 within a wellbore 16 , as previously discussed in relation to FIGS. 1A through 1F .
[0051] As shown in FIG. 3 , the casing bit 10 ′ is similar to the casing bit shown in FIG. 2 and includes an outer bit body 50 and an expander 24 , as discussed hereinabove. However, the casing bit 10 ′ comprises a substantially hollow portion 66 inside of the bit body 50 . The hollow portion 66 is bounded by the bit body 50 at the distal end and around the sides thereof, and by a plate 68 at a proximal end thereof. The plate 68 may comprise a separate body fixedly attached to the outer body 50 . The plate 68 may be positioned so that a distal end of the expander 24 is adjacent a proximal side of the plate 68 . The plate 68 may be fixedly attached to the outer body 50 , for example, by welding the plate 68 to the outer body 50 , using an adhesive, or other known means, as well as combinations thereof. In some embodiments, a shoulder may be formed on the inner surface of the body 50 , such that the plate 68 may rest on the shoulder within the outer body 50 . In such embodiments, the plate 68 also may be welded or otherwise attached to the outer body 50 . The plate 68 may comprise a metal alloy, a polymer material, or a composite material that is relatively softer and/or of lower strength relative to the outer body 50 . The material of the plate 68 may be selected so as to be sufficiently strong and erosion resistant to prevent the plate 68 from damage by hydraulic flow and pressure during drilling operations, but not too strong or wear resistant to prevent subsequent drilling through the plate 68 by another drill bit or tool, as previously discussed.
[0052] In additional embodiments, however, the outer body 50 and the plate 68 may simply be different regions of a common, integral (i.e., monolithic), substantially homogenous body formed of and comprising materials suitable for use as the outer body 50 .
[0053] The plate 68 may have substantially planar sides in some embodiments. In other embodiments, one or both sides of the plate 68 may be non-planar. The plate 68 includes an aperture 72 that extends through a portion thereof. The aperture 72 allows fluid to be pumped through the expander 24 to the fluid passageways 30 during drilling. The aperture 72 may be configured to receive a plug (e.g., ball or dart) trap assembly 74 therein that is configured to receive a plug 32 ( FIGS. 1C-1F ) therein for plugging the hollow portion 66 and inhibiting flow to the hollow portion 66 and the fluid passageways 30 . In some embodiments, the aperture 72 is threaded to receive a plug trap assembly 74 having complementary threads thereon. The plug 32 also may comprise a material that is relatively easy to subsequently drill through using another drill bit, but that has physical properties sufficient to plug the plug trap assembly 74 and withstand the fluid pressure differential across the plug 32 that results upon pressurization of the space 37 ( FIGS. 1D and 1E ) distal to the expander 24 but proximal to the plate 68 when the expander 24 is being forced through expandable casing 14 .
[0054] One or more fluid passageways 30 may extend through the casing bit 10 ′ to allow fluid to be pumped through the expander 24 and the plate 68 and out from the casing bit 10 ′ through the fluid passageways 30 during a drilling process. A section of each of the fluid passageways 30 may extend through the outer body 50 and in communication with the hollow portion 66 . During drilling, a drilling fluid may be pumped through the fluid passageway 62 and the aperture 72 into the hollow portion 66 and out through the fluid passageways 30 .
[0055] As discussed above, the expander 24 may comprise a fluid passageway 62 that extends longitudinally through the expander 24 in some embodiments. Furthermore, the expander 24 may have a shape configured to define at least one cavity 64 ′ when the expander 24 is positioned within the casing bit 10 ′. The cavity 64 ′ may be located and shaped to allow fluid to flow into the cavity 64 ′ from the fluid passageway 62 when fluid is pumped in the distal direction down through the expander 24 through the fluid passageway 62 . The shape of the cavity 64 ′ may be configured to provide a net force acting on the expander 24 in the proximal longitudinal direction when fluid within the fluid passageway 62 and the cavity 64 ′ is pressurized. In some configurations of the casing bit 10 ′, in the absence of such a cavity 64 ′, such a net force might not result when the fluid passageway 62 is pressurized until at least some degree of longitudinal separation is attained between the expander 24 and the plate 68 .
[0056] The casing bit 10 ′ may be secured to a distal end 12 of a section of expandable casing 14 by, for example, welding the outer body 50 of the casing bit 10 ′ to the distal end 12 of the expandable casing 14 . In additional embodiments, complementary threads may be formed on the casing bit 10 ′ and the distal end 12 of the expandable casing 14 , and the casing bit 10 ′ may be threaded to the distal end 12 of the expandable casing 14 to secure the casing bit 10 ′ to the expandable casing 14 . In such embodiments, the interface between the casing bit 10 ′ and the expandable casing 14 optionally may be welded to further secure the casing bit 10 ′ to the expandable casing 14 and threading the casing bit 10 ′ to the expandable casing 14 . Other methods such as, for example, brazing, also may be used to secure the casing bit 10 ′ to the expandable casing 14 .
[0057] FIG. 4 illustrates an embodiment of an outer body 50 ′ of a casing bit 10 ( FIG. 2 ) of the present invention. A casing bit 10 , 10 ′ comprising an outer body 50 ′ as shown in FIG. 4 comprises a casing drilling bit, and may be used to drill with expandable casing 14 attached thereto. The outer body 50 ′ may be formed of and comprise, for example, a metal or metal alloy (e.g., steel, aluminum, brass, or bronze), or a composite material including particles of a relatively harder material (e.g., tungsten carbide) embedded within a relatively softer metal or metal alloy (e.g., steel, aluminum, brass, or bronze). The material of the outer body 50 ′ may be selected to exhibit physical properties that allow the outer body 50 ′ to be drilled through by another drill bit after the casing bit 10 has been used to advance a section of expandable casing attached thereto into a subterranean formation.
[0058] Cutting structures may be provided on exterior surfaces of the outer body 50 ′. For example, the outer body 50 ′ may comprise a plurality of blades 80 that define fluid courses 82 therebetween. Fluid passageways 30 may be formed through the outer body 50 ′ or allowing fluid (e.g., drilling fluid and/or cement) to be pumped through the interior of the casing bit 10 , 10 ′, out through the fluid passageways 30 , and into the annulus between the wall of the formation in which the wellbore 16 is formed and the exterior surfaces of the casing bit 10 , 10 ′ and the expandable casing 14 to which the casing bit 10 , 10 ′ may be attached. Optionally, nozzles (not shown) may be secured to the outer body 50 ′ within the fluid passageways 30 to selectively tailor the hydraulic characteristics of the casing bit 10 , 10 ′. Cutting element pockets may be formed in the blades 80 , and cutting elements 86 , such as, for example, polycrystalline diamond compact (PDC) cutting elements, may be secured within the cutting element pockets.
[0059] Also, each of blades 80 may include a gage region 88 that together define the largest diameter of the outer body 50 ′ and, thus, the diameter of any wellbore 16 formed using the outer body 50 ′ and the casing bit 10 , 10 ′. The gage regions 88 may be longitudinal extensions of the blades 80 . Wear resistant structures or materials may be provided on the gage regions 88 . For example, tungsten carbide inserts, cutting elements, diamonds (e.g., natural or synthetic diamonds), or hardfacing material may be provided on the gage regions 88 of the outer body 50 ′.
[0060] In some instances, the size and placement of the fluid passageways 30 that are employed for drilling operations may not be particularly desired for cementing operations. Furthermore, the fluid passageways 30 may become plugged or otherwise obstructed during a drilling operation. As shown in FIG. 4 , the outer body 50 ′ of the casing bit 10 , 10 ′ may include one or more frangible regions 85 that can be breached (e.g., a metal disc that can be fractured, perforated, ruptured, removed, etc.) to form one or more additional apertures that may be used to provide fluid communication between the interior and the exterior of the outer body 50 ′. Drilling fluid and/or cement optionally may be caused to flow through such frangible regions 85 after breaching the same.
[0061] In additional embodiments, the outer body 50 ′ may not include blades 80 and cutting elements 86 , like those shown in FIG. 4 . Furthermore, the outer body 50 ′ may comprise other cutting structures such as, for example, deposits of hardfacing material (not shown) on the exterior surfaces of the outer body 50 ′. Such a hardfacing material may comprise, for example, hard and abrasive particles (e.g., diamond, boron nitride, silicon carbide, carbides or borides of titanium, tungsten, or tantalum, etc.) embedded within a metal or metal alloy matrix material (e.g., an iron-based, cobalt-based, or nickel-based metal alloy).
[0062] FIG. 5 illustrates another example embodiment of an outer body 50 ″ of a casing bit 10 , 10 ′ ( FIGS. 2 and 3 ) of the present invention. A casing bit 10 , 10 ′ comprising an outer body 50 ″ as shown in FIG. 5 comprises a casing reaming bit, and may be used to ream a previously drilled wellbore 16 as the casing reaming bit is advanced into the wellbore 16 on a distal end of expandable casing 14 . The outer body 50 ″ may be generally similar to the outer body 50 ′ of FIG. 4 , and may comprise a plurality of blades 80 that define fluid courses 82 therebetween. Fluid passageways 30 may be formed through the outer body 50 ″ or allowing fluid (e.g., drilling fluid and/or cement) to be pumped through the interior of the casing bit 10 , 10 ′, out through the fluid passageways 30 , and into the annular space between the walls of the formation in which the wellbore 16 is formed and the exterior surfaces of the casing bit 10 , 10 ′ and the expandable casing 14 to which the casing bit 10 , 10 ′ may be attached. Cutting element pockets may be formed in the blades 80 , and cutting elements 86 , such as, for example, polycrystalline diamond compact (PDC) cutting elements, may be secured within the cutting element pockets. In additional embodiments, the outer body 50 ″ may not include blades 80 and cutting elements 86 , like those shown in FIG. 5 . Furthermore, the outer body 50 ″ may comprise other cutting structures such as, for example, deposits of hardfacing material 87 on the exterior surfaces of the outer body 50 ″. Such a hardfacing material may comprise, for example, hard and abrasive particles (e.g., diamond, boron nitride, silicon carbide, carbides or borides of titanium, tungsten, or tantalum, etc.) embedded within a metal or metal alloy matrix material (e.g., an iron-based, cobalt-based, or nickel-based metal alloy). Wear-resistant bearing elements 84 such as, for example, tungsten carbide ovoids, also may be provided on exterior surfaces of the outer body 50 ″.
[0063] Although the foregoing description contains many specifics, these are not to be construed as limiting the scope of the present invention, but merely as providing certain embodiments. Similarly, other embodiments of the invention may be devised which do not depart from the scope of the present invention. The scope of the invention is, therefore, indicated and limited only by the appended claims and their legal equivalents, rather than by the foregoing description. All additions, deletions, and modifications to the invention, as disclosed herein, which fall within the meaning and scope of the claims, are encompassed by the present invention.
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Casing bits include an expander for enlarging an inner diameter of expandable casing at least partially disposed within a body of the casing bits. Drilling assemblies include a casing bit attached to an end of expandable casing, and an expander disposed in proximity to the casing bit and a distal end of the expandable casing. Methods of forming casing bits include positioning an expander in proximity to a body of a casing bit. Methods of forming drilling assemblies include positioning an expander in proximity to a body of a casing bit and a distal end of expandable casing, and attaching the casing bit to the end of the expandable casing. Methods of casing a wellbore include one or both of drilling and reaming a wellbore using a casing bit attached to a distal end of expandable casing, and forcing an expander through the expandable casing.
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CROSS REFERENCE TO RELATED APPLICATIONS
This patent application relates to, and claims the priority benefit from, U.S. Provisional Patent Application Ser. No. 60/394,272 filed on Jul. 9, 2002 and which is incorporated herein in its entirety.
BACKGROUND OF THE INVENTION
This invention relates to robotic manipulators for moving and positioning an object in space, and more particularly the present invention relates to light weight cable actuated active/passive parallel manipulators.
BACKGROUND OF THE INVENTION
Robotic manipulators may be divided into two main categories, parallel and serial manipulators. Serial manipulators, which are more common in the industry, have several links in series usually connected by rotary or sliding joints. They are analogous to the human arm which has a series of links hinged at the shoulder, elbow and wrist. The configuration of serial manipulators necessitates the location of the driving motors to be at the joints themselves or the use of a heavy or complicated linkage for transferring the motion from the base of the robot to the joints. This is a disadvantage since it requires the movement of the large mass of the manipulator and drives even for a small payload. Further, the positional error of the end effector of a serial manipulator is the accumulation of the errors in the individual links so that by increasing the size or number of links the error associated with the position of the end effector increases.
In contrast to serial manipulators, the links of a parallel manipulator function in parallel to determine the movement of the end effector. A flight simulator and camera tripod are two examples of this kind of mechanisms. If one of the legs of a tripod is extended or moved, it changes the position of the end point. Parallel manipulators have relatively lower mass to payload ratio since the links work together and the actuators are mounted on a stationary base. They also have better precision since the error in the end effector is in the same order of actuators' error.
Low inertia, and therefore, high speed manipulation is one of the main applications of parallel robots. U.S. Pat. No. 4,976,5821 issued to Clavel, entitled ‘Device for the Movement of and Positioning of an Element in Space’, and reported further in Clavel, ‘Delta, a Fast Robot with Parallel Geometry’, Proceeding of International Symposium on Industrial Robots, pp. 91-100, April 1988, discloses one of the most successful mechanisms of this kind which produces movement with three pure translational degrees of freedom at its end effector. In this manipulator of Clavel, rotating arms are connected to the end effector using three parallelograms. The parallelograms constrain the end effector to be parallel to the base plate at all times and therefore, three pure translational movements are achieved.
Other manipulator designs such as disclosed in L-W. Tsai, ‘Kinematic of a Three-DOF Platform With Extensible Limbs’, Proceeding of the Conference of Recent Advances in Robot Kinematics, pp. 401-410, 1996, also provide pure translational movement of the end effector with three translational degrees of freedom. In the Tsai mechanism, three linear actuators connect the end effector to the stationary platform with universal joints. The specific configuration of the universal joints guarantees the three translational motions of the end effector.
There are also parallel mechanism robots with 6-DOF such as the hexa pod, see Griffis M., Crane C., et Duffy J., ‘A smart kinestatic interactive platform’, In ARK , pp. 459-464, Ljubljana, 4-6 Jul. 1994, and the hexa robot disclosed in U.S. Pat. No. 5,333,514 issued to Toyama et al. entitled ‘Parallel Robot’.
In general, parallel mechanism robots have higher stiffness to weight ratio, moment and torque capacity, and better accuracy. They also benefit from a simpler mechanism due to the elimination of drive trains and, also lower moving mass due to the stationary location of the actuators. Further reduction in the moving inertia of parallel mechanisms may be achieved by replacing the rigid links with tensile means such as cables. Replacing the rigid arms not only reduces the moving inertia but it lowers manufacturing cost and simplifies the mechanism structure by eliminating many joints.
Using cables in cranes such as disclosed in U.S. Pat. No. 3,286,851 issued to J. R. Sperg entitled ‘Cargo Handling Rig’, and similar applications, see U.S. Pat. No. 5,967,72910 issued to G. F. Foes entitled ‘Bottom Discharge Rotating Ring Drive Silo Unloader’, is older than robotics, however in recent years several attempts have been made to design cable actuated manipulators. Some of these manipulators are designed to imitate human arms and can be considered as serial manipulators with parallel actuators, see U.S. Pat. No. 3,631,737 issued to F. E. Wells entitled ‘Remote Control Manipulator for Zero Gravity Environment’; U.S. Pat. No. 3,497,083 issued to V. C. Anderson, R. C. Horn entitled ‘Tensor Arm Manipulator’; and U.S. Pat. No. 4,683,773 issued to G. Diamond entitled ‘Robotic Device’.
A pure parallel cable actuated mechanism is disclosed in S. Kawamura, W. Choe, S. Tanaka, S. R. Pandian, ‘Development of an ultrahigh Speed Robot FALCON using Wire Drive System’, Proceeding of IEEE Conference on Robotics and Automation, pp. 215-220, 1995. This manipulator has seven active cables to provide 6-DOF for the end effector. This mechanism does not have any rigid link in its structure and the cables are extended in both sides to maintain tension in the cables.
U.S. Pat. No. 4,666,362 issued to S. E. Landsberger and T. B. Sheridan entitled ‘Parallel Link Manipulator’ discloses a manipulator which uses six active cables and a passive collapsible link. The collapsible link applies a pushing force between the moving and stationary platforms in order to keep all cables in tension.
U.S. Pat. No. 5,313,854 issued to H. A. Akeel entitled ‘Light Weight Robot Mechanism’, discloses another combined cable-collapsible mechanism which moves the end point of the collapsible shaft in the space but does not have any control on its orientation.
SUMMARY OF THE INVENTION
Based on the advantages of parallel and cable based manipulators, some new designs are introduced in this work which can be used in ultra high-speed robots with 3 to 6 degrees of freedom. The robotic mechanisms disclosed herein provide more options for the number of degrees of freedom and also more simplicity compared to the current cable-based robots. In the proposed designs a combination of active and passive tensile members, collapsible and rigid links are used to maximize the benefits of both pure cable and parallel mechanisms.
Applications of both passive and active cables in the new designs improve performance, simplicity and feasibility of the robots. An active cable is one whose length is varied by means of a rotating drum. A passive cable is one whose length is constant and which is used to provide a mechanical constraint. In general, compared to rigid link parallel mechanisms the robotic mechanisms disclosed herein advantageously reduce the moving inertia significantly to enhance the operational speed of the robots. They also provide a simpler, more cost effective way to manufacture parallel mechanisms for use in robotic applications, measurements, and entertainments.
The design of new light weight parallel manipulators for high-speed robots using active/passive cables is explained herebelow. The general structure of these manipulators has the following main components (see FIGS. 1 and 2 ):
a) A base platform 24 . b) A moving platform or end effector 22 . c) An extensible or telescoping central post 26 connecting the base 24 to moving platform 22 to apply a pushing force to the platforms. The central post can apply the force by an actuator (active) or spring or air pressure (passive); and d) Active cables 28 . Active cables are those whose lengths change using an actuator; and/or e) Passive cables 42 . Passive cables are cables whose lengths are fixed.
The robotic mechanism may have just active cables, just passive cables, or a combination of both.
In one aspect of the invention there is provided a robotic mechanism, comprising:
a support base, an end effector and a biasing member having opposed ends and attached at one of said opposed ends to the support base and attached at the other of said opposed ends to the end effector; and
at least three cables each connected at a first end thereof to said end effector and said at least three cables having second ends being attached to an associated positioning mechanism for retracting or deploying each of said at least three cables to position said end effector in a selected position in space, said biasing member applying force on the end effector with respect to the support base for maintaining tension in said at least three cables.
The present invention also provides a robotic mechanism, comprising:
a support base, an end effector and a biasing member having opposed ends and pivotally attached at one of said opposed ends to the support base and pivotally attached at the other of said opposed ends to the end effector; and
six cables each connected at a first end thereof to said end effector and said six cables having second ends being attached to an associated positioning mechanism for moving the second ends of the associated cable independently of the other cables, said biasing member applying force on the end effector with respect to the support base for maintaining tension in said six cables, wherein movement of the second ends of the cables by the associated positioning mechanisms changes a position and orientation of the end effector so that the robotic mechanism has six degrees of freedom.
The present invention also provides a five-degree-of-freedom robotic mechanism, comprising:
a support base, an end-effector and a biasing member having opposed ends and pivotally attached at one of said opposed ends to the support base with a universal joint and pivotally attached at the other of said opposed ends to the end-effector with a universal joint; and
five cables each connected at a first end thereof to said end effector and said five cables having second ends being attached to an associated positioning mechanism for moving the second ends of the associated cable independently of the other cables, said biasing member applying force on the end effector with respect to the support base for maintaining tension in said five cables, wherein movement of the second ends of the cables by the associated positioning mechanisms changes a position and orientation of the end-effector
The present invention also provides a robotic mechanism, comprising:
an end effector, a post having opposed ends being pivotally connected at one of said opposed ends to the end effector;
a support base defining a plane and having a hole extending therethrough, an outer ring structure pivotally connected to said support base within said hole for pivotal motion of said outer ring structure out of the plane of said support base, a first actuator for pivoting said outer ring structure, an inner ring structure pivotally mounted to said outer ring structure inside said outer ring structure, said inner ring structure being concentric with said outer ring structure, a second actuator for pivoting said inner ring structure, said inner ring structure having an axis of rotation in the plane of the outer ring, and perpendicular to the axis of rotation of said outer ring structure, said inner ring structure having a central web with a hole therethrough and a universal joint mounted in said hole to the central web, the other end of said post being slidably mounted in said universal joint, bias means connected to said post for biasing said end effector away from said support base;
a first set of three cables each connected at one end thereof to said end effector and the other ends of said first set of three cables being attached to positioning means mounted on said support base for pulling said three cables independently of each other to position said end effector in a selected position in space; and
a second set of three cables each connected at one end thereof to said end effector and the other ends thereof being attached to the other end of said post, said second set of three cables being mounted to said inner ring at substantially 120° with respect to each other and constrained to be parallel to each other between said end effector and said inner ring and wherein when said positioning means moves said end effector to a selected position in its workspace, said second set of three cables maintains said end effector in a plane parallel to the plane of said inner ring.
The present invention also provides a robotic mechanism, comprising:
an end effector, a post having opposed ends being pivotally connected at one of said opposed ends to the end effector using a universal joint, the post having an adjustable length;
a support base defining a plane and having a hole extending therethrough, an outer ring structure pivotally connected to said support base within said hole for pivotal motion of said outer ring structure out of the plane of said support base, a first actuator for pivoting said outer ring structure, an inner ring structure pivotally mounted to said outer ring structure inside said outer ring structure, said inner ring structure being concentric with said outer ring structure, a second actuator for pivoting said inner ring structure, said inner ring structure having an axis of rotation in the plane of the outer ring, and perpendicular to the axis of rotation of said outer ring structure, said inner ring structure having a central web with a hole therethrough and a universal joint mounted in said hole to the central web, the other end of said post being slidably mounted in said universal joint;
a first set of three cables each connected at one end thereof to said end effector and the other ends of said first set of three cables being attached to a positioning mechanism mounted on said support base for pulling said three cables independently of each other to position said end effector in a selected position in space; and
a second set of three cables each connected at one end thereof to said end effector and the other ends thereof being attached to, a winch mounted on said central web of the inner ring assembly, said second set of three cables being guided through pulleys mounted to said inner ring at substantially 120° with respect to each other and constrained to be parallel to each other between said end effector and said inner ring, wherein the winch retracts or deploys all three cables simultaneously and keeps the cable lengths between the inner ring and the end-effector equal so that when said positioning mechanism moves said end effector to a selected position in its workspace, said second set of three cables maintains said end effector in a plane parallel to the plane of said inner ring.
The present invention also provides a robotic mechanism, comprising:
an end effector, a post having opposed ends and an adjustable length being pivotally connected at one of said opposed ends to the end effector;
a support base, the other end of said opposed ends of the post being pivotally connected on a top surface of said support base;
a set of three cables each connected at one end thereof to the end of said post pivotally connected to said end effector and the other ends of each of said first set of three cables being attached to positioning means mounted on said support base for pulling said cables to position said end effector in a selected position in space;
a first longitudinal shaft having a first longitudinal axis and a pulley being rigidly mounted on each end of said first shaft, said first longitudinal shaft being mounted on a bottom surface of said support base and parallel to said support base, the first longitudinal shaft is passing through a first sleeve, a first rotational spring mounted from one end to the first sleeve and from the other end to the first longitudinal shaft for applying a constant torque to the first longitudinal shaft, including a first motor connected to said first longitudinal shaft for rotating said first longitudinal shaft about an axis parallel to the said support base and normal to said first longitudinal shaft, a second longitudinal shaft having a second longitudinal axis and a pulley rigidly mounted on each end of said second shaft, said second longitudinal shaft being mounted on the bottom surface of said support base and parallel thereto and oriented so said first longitudinal axis is perpendicular to said second longitudinal axis, the second longitudinal shaft is passing through a second sleeve, a second rotational spring mounted from one end to the sleeve and from the other end to the second longitudinal shaft applies a constant torque to the second longitudinal shaft, including a second motor connected to said second longitudinal shaft for rotating said second longitudinal shaft about an axis parallel to the said support base and normal to said second longitudinal shaft; and
a first pair of cables with each cable connected at one end thereof to said end effector and the other end of one of the cables being collected by one of the pulleys at the end of the first longitudinal shaft and the other end of the other cable being collected by the other pulley at the other end of the first longitudinal shaft, the first rotational spring mounted in the first sleeve 148 which applies torque to the first longitudinal shaft has both the pulleys rotate and collect the first pair of cables so that the lengths of the cables of the said first pair of cables remain the same and therefore a parallelogram is maintained by the first pair of cables, a second pair of cables with each cable connected at one end thereof to said end effector and the other end of one of the cables being collected by one of the pulleys at the end of the second longitudinal shaft and the other end of the other cable being collected or deployed by the other pulley at the other end of the second longitudinal shaft as said second longitudinal shaft is rotated by the torque provided by the rotational spring mounted in the second sleeve 146 and therefore the length of the cables of said second pair of cables remains the same and thus a parallelogram is maintained by the second pair of cables, and wherein said cables of said first pair of cables are parallel and said cables of the second pair of cables are parallel so that a plane defined by said end effector is maintained parallel to a plane defined by said two longitudinal shafts.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described by way of example only, reference being had to the accompanying drawings in which:
FIG. 1 is a perspective view of a three degree of freedom (DOF) wire actuated parallel robot using active cables constructed in accordance with the present invention;
FIG. 2 is a perspective view of a three degree of freedom wire actuated parallel robot using passive cables;
FIG. 3 is a perspective view of another embodiment of three degree of freedom wire actuated parallel robot using passive cables;
FIG. 4 is a perspective view of a six DOF parallel mechanism using passive cables;
FIG. 5 is a perspective view of a three-to-five DOF parallel mechanism using active and passive cables;
FIG. 6 shows a top view (view A-A in FIG. 5 ) of the base platform and rings of the mechanism of FIG. 5 ;
FIG. 7( a ) shows an overall perspective view of the configuration of active cables in the mechanism of FIG. 5 ;
FIG. 7( b ) shows a detailed view of the portion of FIG. 7( a ) in the square box;
FIG. 8( a ) shows an overall perspective view of the configuration of the passive cables in the mechanism of FIG. 5 ;
FIG. 8( b ) shows a detailed view of a portion of the passive cable mechanism of FIG. 8( a );
FIG. 8( c ) shows a side view of the passive cable configuration of FIG. 8( a );
FIG. 9 is a perspective view showing the connection of passive cables to the bottom end of the center post;
FIG. 10 shows the mechanism of FIG. 5 in two positions, vertical and tilted at an angle from the vertical showing the moving platform remains parallel to the base platform;
FIG. 11( a ) is an overall perspective view of a three-to-five DOF robotic mechanism;
FIG. 11( b ) is a close up detailed perspective view of the wire tensioning mechanism of the robotic mechanism of FIG. 11( a );
FIG. 12 is a top perspective view of the mechanism of FIG. 11 a absent the end effector and central post showing the tensioning mechanism for the passive cables used to maintain the moving platform parallel to the base;
FIG. 13 shows the configuration of active cables for positioning the central post of the mechanism of FIG. 11 ;
FIG. 14 is a perspective view of a hybrid parallel mechanism using seven active cables that can produce between three and five degrees of freedom for the moving platform;
FIG. 15 is a perspective view of the central extensible rod and three active cables for the mechanism of FIG. 14 ;
FIG. 16 is a bottom view of the mechanism of FIG. 14 ;
FIG. 17 is a perspective view of three degree of freedom parallel planar manipulator using active cable;
FIG. 18 is a bottom view of the moving platform component connection for planar manipulator;
FIG. 19 is a perspective view of two degree of freedom parallel planar manipulator using an active cable;
FIG. 20 is a perspective view of a parallel planar manipulator using a passive cable;
FIG. 21 is a bottom view of three degree of freedom parallel planar manipulator using a passive cable;
FIG. 22 shows the parallelism of the moving platform enforced by two parallelograms;
FIG. 23 is a perspective view of a two degree of freedom parallel planar manipulator driven by passive cables with the orientation constrained by a winch mechanism; and
FIG. 24 shows a perspective view of a three degree of freedom parallel planar manipulator driven by passive cables with the orientation controlled by a cam and a winch mechanism.
DETAILED DESCRIPTION OF THE INVENTION
1. Three-Degree-of-Freedom Parallel Mechanism Using Active Cables
A three-degree-of-freedom parallel robotic mechanism using active cables constructed in accordance with the present invention is shown generally at 20 in FIG. 1 and includes a moving platform 22 that is attached to base platform 24 using an extensible or telescoping central post 26 and three sets of parallel cables 28 with one end of each of cable attached to platform 22 and the other ends of each pair of cables attached to an associated winch assembly 30 . Each winch assembly 30 includes a drum 32 mounted for rotation in a frame 36 which is attached to the base 24 to keep the drum 32 in place and also to guide the cables 28 to the drum via two holes 39 located in the top plate 38 of the frame 36 . The extensible post 26 is attached to the platform 22 (end-effector) and base 24 by universal joints 34 at both ends of the post to prevent the rotation of the moving platform 22 . The extensible center post 26 applies a compression force between the platforms 22 and 24 using a linear actuator such as a hydraulically, pneumatically, and electrically powered cylinder. Alternatively, a linear motor (active element) or using a preloaded spring, or air pressure (passive element) may be employed in alternative embodiments of the mechanism to maintain tension of cables 28 . Post 26 may be any one of a hydraulically, pneumatically, and electrically powered cylinder.
The motion of the moving platform 22 is controlled by the three pairs of active cables 28 . The two cables of each pair of cables 28 are parallel to each other to make a parallelogram as shown by the closed loop of a-b-c-d in FIG. 1 . A motor controller 31 is connected to the motors 33 for driving the motors as well as being connected to position/velocity sensors on each of the drums 32 . A computer 35 attached to the controller 31 is used to program/command the controller for positioning the cables on each of the winches. A tool 37 is mounted on top of end effector 22 and is controlled by controller 31 or by separate controller 41 . When the end effector 22 is to be positioned in a selected location in its workspace, signals are sent by controller 31 based on its existing program or command signals sent by computer 35 which in turn moves the drums 32 in each winch 30 to either roll up the parallel cables 28 or release them, depending on the particular winch and where in the robotic workspace space the end effector 22 is to be located. The lengths of the three pairs of the cables 28 are adjusted independently to provide three degrees of freedom to the end effector platform 22 .
Due to the three cable-parallelogram structures the moving platform 22 will always be parallel to the base platform 24 and can undergo three translational degrees of motion. This is obtained because the edge a-b in parallelogram a-b-c-d (similarly in the other two parallelograms) is always parallel to edge c-d that is parallel to base platform 24 . Since the three intersecting edges (a-b and the other two similar edges) are always parallel to base platform 24 , the moving platform 22 remains parallel to base platform 24 regardless of the lengths of the pairs of cables 28 . The lengths of each pair of cables 28 are controlled independently by their associated rotating drums 32 . The lengths of each pair of cables 28 determines the center location of the moving platform 22 while the parallelograms keep the platform 22 parallel to the base 24 . The length of the central post 26 changes according to the location of the moving platform 22 and the compression force that is applied to the platform 22 from the central post 26 .
2. Three-Degree-of-Freedom Parallel Mechanism Using Passive Cables
A three-degree-of-freedom parallel robotic mechanism using passive cables constructed in accordance with the present invention is shown generally at 40 in FIG. 2 and includes moving platform 22 that is attached to base platform 24 using an extensible or telescoping central post 26 . As with robot 20 in FIG. 1 , the extensible post 26 is attached to the platforms 22 and 24 by universal joints 34 at both ends of the post to prevent the rotation of the moving platform 22 . There are three pairs of fixed-length cables 42 attached to the moving platform 22 and each pair of cables 42 forms a parallelogram a-b-c-d as seen in FIG. 2 . The ends of each pair of cables 42 at the lower edge c-d of the parallelogram are connected to a link arm 44 using a revolute joint 46 having an axis of rotation coincident with c-d. Each link arm 44 is connected to a bracket 48 using another revolute joint 50 whose axis of rotation is parallel to axis c-d. Frame 48 is attached to base 24 and link arm 44 is rotated by an actuator such as an electrical motor (not shown in the figure). When link arm 44 is rotated about the rotational axis of the lower revolute joint 50 , the upper axis a-b remains parallel to axis c-d which guarantees the moving platform 22 stays parallel to the base platform 24 during any motion.
The same reasoning as to why the moving platform 22 remains parallel with the base 24 in apparatus 20 in FIG. 1 applies to base 24 and platform 22 of apparatus 40 regardless of the angles of arms 44 . Thus platform 22 has a pure translational motion along the X, Y and Z-axes. The extendable center post 26 pushes the platform 22 away from the base 24 and generates tension in the pairs of cables 42 which prevents them from becoming slack.
FIG. 3 shows an alternative embodiment at 60 of a robot constructed following the same principle as robot 40 with the difference being link arm 44 ( FIG. 2 ) is replaced by actuators that move edge c-d and the other two similar axes of the parallelograms parallel to the base platform. As an example, connection rod 46 can be moved horizontally or vertically by a linear actuator attached thereto (not shown) to change the location of rod 46 without modifying its angle with the base 24 . Similarly, connection rod 46 can be attached to a rotary actuator for movement in a plane parallel to the base platform 24 to provide the desired movement of the platform 22 . For all these different motions as long as the axis of connection rods 46 are maintained parallel to the base platform 24 the mechanism 60 will have three translational degrees of freedom in the X, Y and Z directions.
Mechanisms 40 and 60 also include a computer controlled motor controller (not shown) such as computer 35 connected to controller 31 shown in FIG. 1 .
3. Six-Degree-of-Freedom Parallel Mechanism Using Passive Cables
A generalization of the design shown in FIG. 3 can be extended to a 6 degree of freedom robot as shown generally at 66 in FIG. 4 . In this design the extendible center post 26 is attached to the base 24 and moving platform 22 by two spherical joints 56 , or one spherical joint and one universal joint instead of two universal joints as is used in mechanisms 20 , 40 , and 60 in FIGS. 1 , 2 , and 3 . The parallelograms in the previous mechanisms 20 , 40 and 60 defined by the pairs of parallel cables are used to impose mechanical constraints to eliminate three rotational degrees of freedom. In the six degree of freedom robot 66 the ends of cables 42 are connected to separate actuators to provide three extra degrees of freedom. In this design the six cables 42 are still passive and are connected at one end to an associated arm 44 and at the other end to moving platform 22 . Each link arm 44 is connected to a frame 48 with a revolute joint 50 . Frame 48 is attached to the base 24 and link arm 44 is rotated by an actuator such as an electrical motor not shown but similar to the motors and controller shown in FIG. 1 . When link arm 44 is rotated the end points of the cables connected to arms 44 change and as a result the position and orientation of the moving platform 22 can be controlled. The central extensible post 26 applies a pushing force through a spring or air cylinder (not shown in the figure) to keep cables 42 in tension. It should be noted that the design is not limited to the use of assembly 44 , 48 and 50 to move the end points of the cables and any mechanism and actuator (linear or rotary) can be used to achieve the same number of degrees of freedom, as discussed with respect to the mechanism of FIG. 3 . Also, there are no limitations on the location of cable 42 attachment to the moving platform, however, these locations will change the overall workspace of the robot. Mechanism 66 also include a computer controlled motor controller (not shown) such as computer 35 connected to controller 31 shown in FIG. 1 for controlling each of the actuators.
The six degree-of-freedom robotic mechanism of FIG. 4 may be converted to a five degree-of-freedom device by replacing spherical joints 56 connecting post 26 to base 24 and end effector 22 with universal joints and removing one of the six cables 42 and associated link arm 44 and motor. The five degrees of freedom will include three translational and two rotational motions (pitch and yaw). The replacement of the spherical joints with universal joints will eliminate the roll motion of moving, platform 22 with respect to post 26 and fixed platform 24 .
4. Three-to-Five DOF Parallel Mechanism Using Passive and Active Cables
Referring to FIG. 5 , there is shown generally at 70 a hybrid parallel mechanism using a combination of active and passive cables to provide five degrees of freedom for moving platform 22 , including three translational and two rotational motions. In this embodiment of the invention, base platform 24 includes two rings 76 and 74 . The top view of base 24 and the two rings is shown in FIG. 6 . Ring 76 is attached to base platform 24 by two revolute joints 87 diametrically located on opposite sides of ring 76 and having coextensive or coincident axis of rotation. Revolute joints 87 are fixed in ring 76 , and held by collars on base 24 .
Actuator 84 is mounted on base 24 and its shaft is connected to one of the revolute joints 87 to provide a relative rotational motion of ring 76 with respect to base 24 so that ring 76 can be rotated out of the plane of base 24 . Similarly, ring 74 is attached to ring 76 by two revolute joints 86 diametrically located on opposite sides of ring 74 and with revolute joints 86 having coextensive or coincident axis of rotation. The revolute joints 86 are fixed in ring 76 and held by collars in ring 74 . The coextensive axes of rotation of the two revolute joints 86 are normal to the coextensive axes of rotation of the two revolute joints 87 . Actuator 82 is mounted on ring 74 and its shaft is connected to one of the revolute joints 86 to provide a relative rotational motion between rings 74 and 76 for rotating ring 74 out of the plane defined by ring 76 . As a result, ring 74 is connected to base 24 through ring 76 and has two rotational degrees of freedom (pitch and yaw) and its orientation is set by motors 82 and 84 .
At the center of ring 74 there is collar 78 which is attached to ring 74 by a universal joint 80 . When the planes of rings 74 , 76 are in the same plane as base 24 and collar 78 is normal to the base the axes of rotation of universal joint 80 and revolute joints 86 and 87 are all in a single plane. Also, center post 72 can only slide in collar 78 without any rotation. Platform 22 ( FIG. 5 ) is connected to center post 72 by universal joint 89 ( FIG. 7( a )). Universal joint 89 prevents the rotation of platform 22 with respect to the longitudinal axis of center post 72 .
Referring again to FIG. 7( a ), the top end of center post 72 is attached to three active cables 88 which are used to orient the center post 72 in space. FIG. 7( a ) shows the mechanism without the passive cables 98 and movable platform 22 to show more clearly the active cables 88 . The active cables 88 are attached at one end thereof to the tip of center post 72 . Referring particularly to FIG. 7( b ), each of the active cables 88 is pulled and accumulated using an associated winch assembly that includes a pulley 92 and a motor 90 which rotates the pulley. Pulley 92 and motor 90 of each winch assembly is mounted in housing 96 which is attached to the base platform 22 and each of the cables 88 passes through a hole 94 located in the top of the associated housing 96 . The tip of center post 72 can be moved to any point in the workspace by changing the length of active cables 88 . The center post 72 applies a pushing force to cables 88 to keep them in tension at all times. This force can be generated by means of passive elements such as spring 73 which applies the force between collar 78 and center post 72 . In an alternative embodiment an active element such as a linear motor (not shown in the figures) may be used instead.
There are three passive cables 98 (best seen in FIGS. 8( a ) and 8 ( b )) attached at one end to the moving platform 22 and at the other end to the bottom end of center post 72 (see FIG. 9) . Passive cables 98 are parallel to each other in the section between ring 74 and platform 22 ( FIG. 10 ) and are used to maintain the moving platform 22 parallel to ring 74 so that any orientation of ring 74 transfers to platform 22 .
Referring to FIG. 8( a ), the passive cables 98 from platform 22 are guided through pulleys 100 which are mounted to brackets 103 (see FIG. 8( b )), which in turn are attached to ring 74 using revolute joints (not shown). The revolute joints allow the pulleys 100 to adjust themselves with respect to the direction of the associated cables 98 .
Three other pulleys 104 (see FIG. 9 ) are mounted in brackets 106 which are mounted on a frame 108 which is attached to collar 78 . The axes of pulleys 100 are in the same plane which passes through the center of universal joint 80 ( FIG. 6 ). Also, the axes of pulleys 104 are in the same plane which passes through universal joint 80 . These conditions are required to keep the platform 22 parallel to ring 74 .
Pulleys 104 guide the cables 98 to their attachment point at the bottom end of center post 110 . Three springs 112 are in series with cables 98 . These three springs 112 are used to provide tension in passive cables 98 and also compensate for small changes in the length of cables 98 when the center post 72 deviates from its vertical position.
The three passive cables 98 maintain the platform parallel to ring 74 as shown in FIG. 10 for a 2D situation. In an ideal configuration, pulleys 100 and 104 have zero diameters. As seen in the figure, regardless of the angle of 72 BC=EF and DC=DE. Since the overall length of the cables ABCD and GFED are equal, AB=GF all the time. This constitutes a parallelogram which guarantees end effector 22 stays parallel to base platform 24 .
The embodiment shown at 70 in FIG. 5 is a five degree-of-freedom mechanism that has three translational motions of the moving platform 22 that are provided by actuators 90 and active cables 88 , and the two rotational degrees of freedom are provided by actuators 82 and 84 to orient moving platform 22 . The translational and rotational motions of the moving platform are independent which result in simple kinematics of the mechanism. Mechanism 70 can be converted into a three degree of freedom mechanism by removing rings 74 and 76 and connecting pulleys 100 and their frames directly to base 24 . In this configuration platform 22 is always parallel to the base and its location can be changed by active cables 88 and motors 90 . Alternatively, a three degree of freedom mechanism can be obtained by locking rings 74 and 76 with respect to base 24 .
5. Alternative Three-to-Five DOF Parallel Mechanism Using Active Cables
Referring to FIG. 11( a ), there is shown generally at 200 a hybrid parallel mechanism using a combination of active and passive cables to provide five degrees of freedom for moving platform 22 , including three translational degrees of freedom and two rotational degrees of freedom. The overall structure of mechanism 200 is very similar to mechanism 70 in FIG. 5 except for the central post 26 and the way passive cables 98 keep the moving platform 22 parallel to ring 74 . The central post in this design is extensible and connected to both moving platform 22 and ring 74 with universal joints. It further applies an active or passive pushing force to the platform and ring via a spring or air cylinder (not shown in the figure) or it could be a linear motor to continuously adjust the force.
A close-up of the mechanism that keeps platform 22 parallel to ring 74 is shown in FIGS. 11 b and 12 . Passive cables 98 are guided to a winch mechanism which includes a drum 97 mounted for rotation in a frame 107 and driven by a motor 99 . Frame 107 is attached to ring 74 . Three pulleys 100 are mounted on frames 106 that are connected to ring 74 by revolute joints 103 and spaced 120° with respect to each other around ring 74 . Two pulleys 101 are mounted on associated frames 105 that are connected directly to ring 74 . These two pulleys 101 receive two of the cables 98 from two of the pulleys 100 which are then wrapped on drum 97 . Cable 98 from the third pulley 100 goes directly to drum 97 , best seem in FIG. 12 . The cables 98 are wound on drum 97 by applying a torque generated by passive elements like rotational springs or active elements such as electrical or air motors shown schematically by 99 . As seen in FIG. 12 the lengths of cables 98 between pulleys 100 and drum 97 are independent from the position and orientation of platform 22 . Also, cables 98 are wrapped around one single drum 97 and as a result the change in the lengths of cables 98 between pulleys 100 and platform 22 will be the same in any robot's configurations. Now, if cables 98 are attached to platform 22 such that their lengths between pulleys 100 and connection points on platform 22 become equal and parallel to the central post 26 , each two cables 98 will make a parallelogram and therefore platform 22 will remain parallel to ring 74 regardless of its position in the workspace.
FIG. 13 shows the arrangement of the active cables 88 that are the same as the arrangement of the active cables in mechanism 70 in FIG. 7( a ). Referring again to FIG. 11 a , mechanism 200 is a five degree of freedom mechanism that includes three translational degrees of freedom of the moving platform 22 provided by actuators 90 and active cables 88 , and the two rotational degrees of freedom provided by actuators 82 and 84 to orient moving platform 22 in its workspace. The translational and rotational motions of the moving platform 22 are independent of each other which results in simple kinematics of the mechanism. Mechanism 200 may be converted into a three degree of freedom mechanism by removing rings 74 and 76 and connecting pulleys 100 and their frames directly to base 24 . This way platform 22 is always parallel to the base 24 and its location can be changed by changing the length of active cables 88 using motors 90 .
In summary, the embodiment shown in FIGS. 11 , 12 and 13 is a 5 dof mechanism. In this mechanism the second set of cables are not attached to the bottom end of the post. They are pulled and collected by winch 97 . There are five pulleys mounted on the inner ring in order to guide the three cables to the winch. This winch pulls and collects all three cables simultanously and hence keeps the cable lengths between the inner ring and the end-effector equal. Therefore, the end-effector stays parallel to the inner ring plane. Winch 97 can be connected to a motor or to a rotational spring in order to pull cables and keep them in tension. In this mechanism the post can be as simple as the mechanisms of FIGS. 1 to 5 .
6. Three-to-Five DOF Parallel Mechanism Using Active Cables
FIG. 14 shows a hybrid parallel mechanism at 120 using seven active cables that can produce between 3 and 5 degrees of freedom for the moving platform 22 . In this embodiment, the moving platform 22 , base platform 24 , and extensible center post 26 and universal joint 34 are similar to the previous embodiments. Three active cables 122 as shown in FIGS. 14 and 15 are attached at one end to the top of extensible center post 26 and the other ends are attached to winches 124 which are mounted in bracket frames 126 attached to platform 24 . Winches 124 , which control the lengths of cables 122 control the end location of the extensible rod in the space.
Referring particularly to FIGS. 14 and 16 , two pairs of cables 130 and 132 form two parallelograms. The pair of cables 130 are pulled and collected by two pulleys 136 mounted on the ends of shaft 138 . The pair of cables 132 are pulled and collected by two pulleys 140 mounted on the ends of shaft 142 . Both shafts 138 and 140 and the associated pulleys mounted on the ends of the respective shafts form a single body and therefore, the two pulleys rotate simultaneously with the shaft. Shaft 142 rotates inside collar 146 . There is also a source of constant torque acting between shaft 142 and collar 146 . This torque can be applied by a spring which maintains the cables 132 in tension. Similarly, shaft 138 rotates inside a collar 148 . There is also a source of constant torque acting between shaft 138 and collar 148 which may be applied by a spring and this keeps the cables 130 in tension. Maintaining the shafts 138 and 142 parallel to base 24 and platform 22 ′ ensures that the platform 22 is parallel to the base 24 . Collars 146 and 148 are mounted to frame 150 and collar 146 is connected to motor 152 and collar 148 is connected to motor 154 . The motors rotate the collars connected thereto and this rotation is directly transferred to the platform 22 which alters the orientation of the platform 22 .
Each of the two longitudinal shafts 138 and 142 mounted on the bottom surface of the support plane are responsible for forming a parallelogram. Each of these two shafts has two pulleys rigidly connected at the two ends. The two shafts are initially parallel to the support base plane and normal to each other. In FIG. 16 , there are two sleeves shown as 146 and 148 . The two shafts pass through these sleeves and can rotate about their longitudinal axis. There are also rotational springs (not shown in the figure) used to apply a torque between each sleeve and its associated shaft. Therefore, the shafts are under a passive torque so that they pull and collect the cables. As a result, the two pairs of parallel cables remain in tension and build two parallelograms which force the end-effector to be parallel with the two longitudinal shafts. If we rotate sleeves 146 , 148 about an axis parallel to the support base plane and normal to the longitudinal axes of the shafts using motors 152 and 154 , the rotation will be directly transferred to the end-effector because the end-effector has to stay parallel to the longitudinal axes of the shafts. Therefore, the two motors control the orientation of the end-effector and the mechanism will provide 5 degrees of freedom.
7. Three DOF Planar Parallel Mechanism Using Active Cables
A general three degree of freedom planar parallel mechanism using active cables constructed in accordance with the presented invention is shown generally at 170 in FIG. 17 . The moving platform, 22 is attached to a base plate 172 by extensible or telescoping central post 174 and three active cables 176 , through a winch assembly. See FIG. 18 for details. The base plate 172 provides a reference for the moving platform 22 , and its function is identical to the base platform 24 of FIG. 1 . The central post 174 is connected by revolute joint 180 to the bottom of moving platform 22 having an axis of rotation 179 (see FIG. 18 for details), and base plate 172 by a revolute joint 178 with the pivoting axes 179 of the revolute joints 178 and 180 being perpendicular to the workspace of the robot. The out of plane moment induced on the moving platform 22 is counter-balanced by these revolute joints. A clevis pin type of revolute joint is a reasonable choice for this component. The cables 176 do not need to be coplanar but they must be held in tension. Cables 176 may be attached to platform 22 by revolute joints 183 having axis of rotation parallel to axis 179 of joint 180 . The purpose of the revolute joints 183 is to reduce the amount of bending at the attachment points on the cables 176 to platform 22 which can increase the life span of the cables and joints. Other attachment devices such as eyelets may be used as well to reduce the bending while using the same design. The central post 174 is used to exert a tensile force on the cables 176 .
Each of the three winch assemblies 188 used in apparatus 170 comprises a drum 190 in a housing 192 with each drum being driven by a motor 194 , with each housing 192 having a pilot hole 196 in its top surface through which the associated cable 176 passes to be wound on drum 190 . This mechanism uses a pair of cables 176 (hence two winch assemblies 188 ) on one side of the central post 174 and at least one cable 176 and its associated winch 188 on the opposite side of post 174 . As the motor 194 turns, the drum 190 takes up or releases its associated cable 176 . The pilot hole 196 is used to position and set a reference point for the cables. The positioning of the moving platform 22 is controlled directly by the amount of cable released by the drum. A computer controlled motor controller systems (not shown) such as computer 35 connected to controller 31 shown in FIG. 1 is used to adjust the length of the active cables.
In mechanism 170 shown in FIG. 17 , the two parallel cables are similar to the parallelograms in the other embodiments and as long as their lengths remain the same the end effector 22 can only move parallel to the base. However, in this design we have considered two motors to be able to change both the orientation and location of the end effector through three actuators.
8. Two DOF Planar Parallel Mechanism Using Active Cables.
In mechanism 170 of FIG. 17 , the cables 176 from the side of post 174 having the two winches 188 side-by-side have the ability to constraint the orientation of the moving platform 22 . If these cables are equal in length, the cables 176 and the moving platform 22 forms a parallelogram for the same reasoning as the apparatus shown in FIG. 1 . Thus, the moving platform 22 will be parallel to the top plane 173 of the base plate 172 . On the other hand, if cables 176 are different in length, the combination of all three cables determines the orientation of the moving platform 22 . Therefore, referring to FIG. 19 , a two translational degree of freedom active cable mechanism shown generally at 200 can be constructed by replacing the two adjacent winch assemblies 188 shown on FIG. 17 with a two cable winch assembly 30 shown in FIG. 1 . Note that the resulting mechanism requires only two motors 194 and 33 only. In FIG. 19 , a design with one drum and motor for the two cables on the same side of post 174 maintains the orientation of end effector 22 is fixed, which is parallel to the base 172 in FIG. 19 . One of the two paired cables could be longer or shorter with respect to the other thereby inclining the end effector 22 and as long as the length ratio of the two cables remains fixed the orientation or angle of the end effector 22 will remain constant.
9. Three DOF Planar Parallel Mechanism Using Passive Cables
A general three degree of freedom planar parallel mechanism using passive cables in accordance with the present invention is shown generally at 210 in FIG. 20 . The moving platform 22 is attached to the base plate 172 by extensible or telescoping central post 174 and three passive cables 212 each connected at one end of the cables to three link-arms 214 and the other ends connected to platform 22 . The connections of the cables 212 and the central post 174 to moving platform 22 is identical to the connections in mechanism 170 shown in FIGS. 17 , 18 and 19 . The connection of post 174 to base 172 is also the same as in FIG. 17 . Link-arms 214 are pivotally connected to base 172 through revolute joints 218 . Similar to the active cable counterpart mechanism 170 in FIG. 17 , passive cable mechanism 210 also requires a pair of the cables 212 on one side of the central post 174 and at least one cable 212 on the opposite side. The side with two cables 212 controls the orientation of the moving platform 22 . If these cables were equal in length and are parallel to each other, the cables and the tips of the link-arms form two parallelograms. Therefore, the orientation of moving platform 22 will be fixed during movement of the end effector 22 , and in the FIG. 20 it will be parallel to ground. On the other hand, if this pair of cables 212 is orientated differently, the combination of all three cables determines the orientation of the moving platform 22 . It should be pointed out that the motion of ends of the cables 212 attached to arms 214 is not necessarily circular provided by arm 214 , and it can be linear or any other complex trajectory generated by linkage mechanisms. This is analogous to the motion of pins 46 in the mechanism 60 illustrated in FIG. 3 .
Referring to FIG. 21 , a computer controlled motor controller system such as computer 35 connected to controller 31 shown in FIG. 1 is used to control the motor which drives the link arms 214 . FIG. 21 shows a bottom view of the mechanism 210 with the motors 33 attached to the lower revolute joints 218 of the link-arms 214 . The rigid link arms 214 are offset to maximize the rotation of link arms 214 without any interference with each other. Increasing the rotation of link arms 214 will minimize the size of the robot. This applies to the embodiments shown in FIGS. 17 to 24 . The orientation of the cables 212 is determined by the amount of rotation on the link-arms 214 . Coupled with the passive cables 212 , the position and the orientation of the moving platform 22 are controlled. The operating principal is similar to the mechanism illustrated in FIG. 2 .
9. Two DOF Planar Parallel Mechanism Using Passive Cables
The mechanism shown in FIG. 20 can be converted to a two degree of freedom planar manipulator by synchronizing the motion of the paired link-arms. A timing belt (or equivalently a chain-sprocket drive) can be used for that purpose. The configuration can be made by attaching a sheave to the revolute joint 218 and rigidly attach them to the link arm 214 . The synchronizing motion can be achieve by connecting the sheave with a timing belt. A synchronized motion of the paired link-arms 214 ensures the parallelism of the paired cables 212 that in turn restricts orientation of the moving platform 22 . As illustrated in FIG. 22 , when two link-arms 214 are parallel, the close loops B-C-E-F and A-D-B-C form two parallelograms, which forces line A-D (attached to the moving platform) to be parallel with line E-F (attached to the base plate). Hence, the rotating degree of freedom of the moving platform is eliminated, leaving two translational degrees of freedom to the mechanism only.
10. Hybrid Two DOF Planar Parallel Mechanism Using Passive Cables for Positioning and Active Cable for Orientation
FIG. 23 shows another alternative embodiment of a mechanism shown at 220 to achieve the parallelism of the moving platform 22 . In mechanism 220 , the cables 212 that are attached to the moving platform 22 are connected to a beam 222 , which pivots about the free end of a link-arm 224 . The orientation of the beam 222 is constrained using a winch assembly 226 that includes a pair of cables 228 attached to beam 222 , a drum 230 , and a torsion spring (represented by a torsion load 232 ). Since both cables 228 are connected to the same drum 230 , their lengths are always equal to each other. The torsion spring 232 is attached to the drum 230 to maintain tension in cables 228 . Note that drum 230 is passive and its rotation depends on the orientation of arm 224 orientation. Analogous to the configuration shown in FIG. 22 , the drum 230 , the beam 222 , the pairs of cables 228 and 212 , and the moving platform 22 form two parallelograms that ensure the parallelism between the moving platform 22 and the base plate 172 . Hence, the orientation of the moving platform 22 is maintained parallel to the ground.
11. Hybrid Three DOF Planar Parallel Mechanism Using Passive Cables For Positioning And Active Cable For Orientation
Referring now to FIG. 24 , another embodiment of the mechanism shown in FIG. 20 is shown at 240 . Mechanism 240 is similar to mechanism 220 of FIG. 23 but includes a cam 242 that routes one of the cables 228 . The objective of cam 242 is to create a bias on the length of one of the active cables 228 to provide a new degree of freedom to the robot mechanism of FIG. 23 . Adjusting the bias in the cable will allow to control the orientation of the moving platform 22 . The operating principal is similar to a cam-follower mechanism. The linear guide 119 is used to induce a linear motion to cam 242 as shown in FIG. 24 .
When the cam 242 moves towards the center of the mechanism, it routes the inner active cable 228 around the cam face. This effectively shortened the length the routed active cable while leaving the other active cable untouched. The resulting effect is a distortion on the parallelogram formed by the active cables and the beam. The routed cable pulls the beam on one side and forces the beam to tilt towards the routed cable. As a result, the beam 222 will no longer be parallel to ground, but is controlled by this cam 242 . Since the moving platform is parallel to the beam, the orientation of the moving platform is also controlled. The same operation can be performed on the other cable 228 . When the cam 242 moves towards the edge of the robots, it pulls the beam 222 on one side and forces the beam 222 to tilt towards the edge of the robot, which leads to the same rotation on the moving platform 22 .
As used herein, the terms “comprises”, “comprising”, “including” and “includes” are to be construed as being inclusive and open ended, and not exclusive. Specifically, when used in this specification including claims, the terms “comprises” and “comprising” and variations thereof mean the specified features, steps or components are included. These terms are not to be interpreted to exclude the presence of other features, steps or components.
The foregoing description of the preferred embodiments of the invention has been presented to illustrate the principles of the invention and not to limit the invention to the particular embodiment illustrated. It is intended that the scope of the invention be defined by all of the embodiments encompassed within the following claims and their equivalents.
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The present invention provides parallel, cable based robotic manipulators, for use in different applications such as ultra high-speed robots or positioning devices with between three to six degrees of freedom. The manipulators provide more options for the number of degrees of freedom and also more simplicity compared to the current cable-based robots. The general structure of these manipulators includes a base platform, a moving platform or end effector, an extensible or telescoping central post connecting the base to moving platform to apply a pushing force to the platforms. The central post can apply the force by an actuator (active), or spring or air pressure (passive) using telescoping cylinders. The robotic manipulators use a combination of active and passive tensile (cable) members, and collapsible and rigid links to maximize the benefits of both pure cable and conventional parallel mechanisms. Different embodiments of the robotic manipulators use either active cables only, passive cables only, or combinations of active and passive cables. An active cable is one whose length is varied by means of a winch. A passive cable is one whose length is constant and which is used to provide a mechanical constraint. These mechanisms reduce the moving inertia significantly to enhance the operational speed of the robots. They also provide a simpler, more cost effective way to manufacture parallel mechanisms for use in robotic applications.
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This is a division of application Ser. No. 571,041, filed Apr. 23, 1975, now U.S. Pat. No. 3,952,033.
BRIEF SUMMARY OF THE INVENTION
This invention relates to novel compounds useful as intermediates for the synthesis of the natural prostaglandins and their congeners. These novel compounds may be represented by the following structural formula: ##STR1## wherein R is a lower alkyl group of 1 to 4 carbon atoms; X is a divalent alkylene group of from 1 to 9 carbon atoms optionally substituted with one or two lower alkyl groups of from 1 to 4 carbon atoms, or a divalent alkylene group of from 3 to 9 carbon atoms having one double bond and optionally substituted with one or two lower alkyl groups of from 1 to 4 carbon atoms; and Z is a formyl, carboxy or carboalkoxy group wherein the alkoxy moiety has from 1 to 12 carbon atoms. The invention also relates to compounds of the formula: ##STR2## wherein X is as defined hereinabove; Z' is a carboxy or carboalkoxy group wherein the alkoxy moiety has from 1 to 12 carbon atoms; and Y is ethylene or cis-vinylene.
DETAILED DESCRIPTION OF THE INVENTION
The formation of the novel compounds of this invention and their ultimate conversion to prostaglandins may be accomplished as illustrated in the following Flowsheet for the synthesis of prostaglandins E 2 (XII) and E 1 (XXII), and 11-deoxyprostaglandins E 2 (XIV) and E 1 (XXVI). In the Flowsheet, R is as defined hereinabove. ##STR3##
In accordance with the illustrative equations of the Flowsheet hereinabove, ethyl β-(2-furyl)propionate (I) [I. F. Bel'skii, et al., Dokl. Akad. Nauk SSSR, 152, 862 (1963); Chem. Abstr., 60, 1577d (1964)] is subjected to oxidative alkoxylation, for example with bromine in a lower alkonal (e.g. methanol) in the presence of a base such as sodium carbonate or sodium acetate [N. Clauson-Kaas, Acta. Chem. Scand., 1, 619 (1947)] or by electrolysis [N. Clauson-Kaas et al. ibid., 6, 531 (1952)] to provide the ester (II).
Reduction of the ester group in (II) with a dialkylaluminum hydride reagent, for example diisobutylaluminum hydride (one equivalent), at low temperature (-78° to -65° C.) in an inert solvent such as toluene followed by hydrolysis under neutral conditions gives the aldehyde (IV).
Reaction of freshly-distilled (IV) with a phosphorous ylid, for example the sodium salt of 4-carboxybutyltriphenyl phosphorane (III) (E. J. Corey, et al., J. Am. Chem. Soc., 91, 5675 (1969)] in dimethyl sulfoxide solution at 17°-25° C. results in the formation of the cis-olefin (V). The 2,5-dimethoxy(or dialkoxy)-2,5-dihydrofuran group in (V) represents a latent enedione structure as indicated by the formation from it of linear compound (VI). The hydrolysis of (V) to (VI) may be effected with a weak acid, for example acetic acid or sodium dihydrogen phosphate, in a solvent system containing water and an organic cosolvent such as dioxane at a temperature of 25°-100° C. The linear enedione (VI) may be isolated or more conveniently subjected to further reaction in the hydrolysis system to induce the cyclization reaction which affords hydroxycyclopentenone (VIII).
With proper choice of conditions, for example operation in the pH range of 5.0 to 6.5 in the above temperature range, the dihydrofuran (V) directly affords the hydroxycyclopentenone (VIII). The product (VIII) may be isolated for the next step or used in situ in the rearrangement which leads to prostaglandin precursor (VII). In the latter case the hydrolysis solution, as defined above, is acidified with a strong acid, for example sulfuric acid, and the rearrangement of (VIII) to (VII) is allowed to occur at a temperature of 25°-100° C., preferably about 65° C. for several hours. When the reaction is complete, as evidenced by the nearly total consumption of (VIII), the solution is extracted and the product (VII) is purified according to well-known procedures.
In the case where intermediate (VIII) is isolated, the rearrangement to (VII) may be carried out in a solution of strong acid as indicated above or in a solution of a weak base, for example sodium carbonate, in aqueous solution. For this reaction the best conditions are pH in the range 10.0-10.5 at about room temperature. The product (VII) is isolated and purified as above after acidication of the reaction solution.
The hydroxycyclopentenone (VII) represents a useful intermediate for the synthesis of prostaglandin E 2 (XII). For this purpose the hydroxy groups of (VII) are protected, for example by reaction with dihydropyran in the presence of an acid catalyst to give the bis-tetrahydropyranyl derivative (IX). Alternatively, hydroxy acid (VII) may be esterified, for example with ethereal diazomethane, to provide methyl ester (X). The remaining hydroxy group in X is protected as the tetrahydropyranyl ether to give (XI). The transformation of (IX) and (XI) to prostaglandin E 2 , as well as the conversion of (XI) as the 4R enantiomer, has been reported by J. B. Heather et al., Tetrahedron Letters, 2313, (1973).
The cyclic acetal (V) is also a useful precursor to prostaglandins of the 11-deoxy class. When (V) is subjected to hydrolysis, as described above, in the presence of titanium trichloride, the linear enedione formed in the hydrolysis is reduced instead of cyclized to give ketoaldehyde (XIII). This conversion of (V) to (XIII) may be effected with a weak acid, for example acetic acid in the presence of sodium acetate, in a solvent system containing water and an organic cosolvent, such as dioxane, at 0°-50° C. and in the presence of at least two molar equivalents of titanium trichloride.
The ketoaldehyde (XIII) thus produced is converted to cyclopentenone (XV) by aldol cyclization with catalysis by a basic reagent, for example sodium hydroxide in aqueous solution. Cyclopentenone (XV) has been used as an intermediate for the synthesis of 11-deoxyprostaglandin E 2 (XIV) [P. A. Grieco and J. J. Reap, J. Org. Chem., 38, 3413 (1973)].
For preparation of cyclopentenone (XX), a useful intermediate for the preparation of prostaglandin E 1 (XXII) [K. F. Bernady and M. J. Weiss, Prostaglandins, 3, 505 (1973)], a suitable starting material is 8-(2-furyl)-8-oxooctanoic acid (XVI) [R. I. Reed and W. K. Reid, J. Chem. Soc., 1963, 5933]. Transformation of (XVI) to 8-(2-furyl)octanoic acid (XVII) is accomplished by Wolf-Kishner reduction which utilizes hydrazine and a solution of sodium hydroxide. The carboxyalkylfuran (XVII) is subjected to oxidative alkoxylation by procedures analogous to those used for preparation of the precursor to prostaglandin E 2 , for example with bromine in a lower alkanol (e.g., methanol) in the presence of sodium carbonate, to provide the 2,5-dimethoxy(or dialkoxy)-2,5-dihydrofuran derivative (XVIII). The sequence of reactions leading to the useful compound (XX) from (XVIII) is carried out essentially as described above for the preparation of (IX) from (V). As before, intermediates (XIX) and (XXI) may be isolated or preferably used in situ as in the case of (VI) and (VIII).
The cyclic acetal (XVIII) is also a useful intermediate for the preparation of 11-deoxyprostaglandin E 1 . Reaction of (XVIII) with a weak acid in the presence of titanium trichloride, as described above for the conversion of (V) to (XIII), affords ketoaldehyde (XXIII). Conversion of (XXIII) to (XXV) is effected with aqueous sodium hydroxide, as described above for the conversion of (XIII) to (XV). The carboxy group in (XXV) is protected by esterification, for example by treatment with ethanol in the presence of an acid catalyst to provide the ethyl ester (XXIV). Cyclopentenone (XXIV) has been used as an intermediate for the preparation of 11-deoxyprostaglandin E 1 (XXVI) [M. B. Floyd and M. J. Weiss, Prostaglandins, 3, 921 (1973)].
Adaptation of the above-described procedures to the preparation of the other compounds of this invention essentially involves the lengthening or shortening of, or the introduction of one or two lower alkyl groups into, the side-chains in furans (I) or (XVII) or in phosphonium derivative (III). These adaptations can be accomplished by procedures well-known to the art. For example, isopropyl γ-(2-furyl)-butyrate provides 2,5-dihydro-2,5-di-n-propoxy-2-(3'-carboisopropoxypropyl)furan in n-propanol whereas methyl δ-(2-furyl)valerate provides 2,5-dihydro-2,5-diethoxy-2-(4'-carbomethoxybutyl)furan in ethanol when treated in the manner described for the conversion of (I) to (II). Similarly, ω-(2-furyl)caproic acid and ω-(2-furyl)enanthic acid provide 2,5-dihydro-2,5-diethoxy-2-(5'-carboxyentyl)furan and 2,5-dihydro-2,5-diethoxy-2-(6'-carboxyhexyl)furan when treated in ethanol in the manner described for the conversion of (XVII) to (XVIII). Optionally, the furyl acids may be first esterified prior to oxidative alkoxylation, and all 2,5-dihydro-2,5-dialkoxy-2-(carboalkoxyalkyl)furans may be converted to the corresponding aldehydes in the manner described for the conversion of (II) to (IV). Also, the reaction of 3-carboxypropyltriphenylphosphonium bromide and 5-carboxy-3,4-dimethylamyltriphenylphosphonium bromide with 2,5-dihydro-2,5-diethoxy-2-(4'-oxobutyl)furan and 2,5-dihydro-2,5-diethoxy-2-(2'-oxoethyl)furan, respectively, provides the 2,5-dihydro-2,5-diethoxy-2-(7'-carboxy-4'-cis-heptenyl)furan and 2,5-dihydro-2,5-diethoxy-2-(7'-carboxy-5',6'-dimethyl-2-cis-heptenyl)furan.
Certain of the resulting 4-hydroxycyclopentenones and 4-unsubstituted cyclopentenones as well as their conversion to useful prostaglandin types are described in Netherlands patent specifications 7310-276 and 7310-277, both issued Jan. 28, 1974 (see Derwent Central Patents Index, Basic Abstracts Journal, B-Farmdoc, 10735 V/06 and 10736 V/06, respectively). Other useful prostaglandins with one or two lower alkyl substituents in the 2 or 3 positions, are described in U.S. Pat. No. 3,767,695 (Oct. 23, 1973).
The invention will be described in greater detail in conjunction with the following specific examples.
EXAMPLE 1
Preparation of 2,5-dihydro-2,5-dimethoxy-2-(2'-carbethoxyethyl)furan
To a stirred solution of 2-(2'-carbethoxyethyl)furan (42.5 g.) in 750 ml. of methanol containing 53 g. of sodium carbonate at -25° C. is added a solution of 40.5 g. of bromine in 250 ml. of methanol during the course of 2.5 hours. The solution is stirred at room temperature for 30 minutes, diluted with brine, and extracted with diethyl ether. The extract is washed with brine, dried over magnesium sulfate, and concentrated. The residue is distilled to provide a light yellow liquid, b.p. 78°-84° C. (0.2 mm.), ν max 1740 (ester carbonyl group) and 1015 cm - 1 (dimethoxydihydrofuran group).
EXAMPLE 2
Preparation of 2,5-dihydro-2,5-dimethoxy-2-(3'-oxopropyl)furan
To a stirred solution of 48.9 g. of 2,5-dihydro-2,5-dimethoxy-2-(2'-carbethoxyethyl)furan (Example 1) in 800 ml. of toluene was added 263 ml. of 0.89M diisobutylaluminum hydride in toluene during 90 minutes at -75° C. The solution was stirred at -75° C. for 30 minutes and then treated with 5.0 ml. of methanol. The stirred solution is treated with 100 ml. of water, and the resulting mixture is stirred at 0°-5° C. for 15 minutes, saturated with sodium sulfate, and filtered through Celite with the aid of ethyl acetate. The filtrate is washed with brine, dried over magnesium sulfate, and concentrated. The residue is distilled to provide a light yellow liquid, b.p. 76°-78° C. (0.25 mm.), ν max 1725 (aldehyde carbonyl group) and 1015 cm - 1 (dimethoxydihydrofuran group).
EXAMPLE 3
Preparation of 2,5-dihydro-2,5-dimethoxy-2-(7'-carboxy-3'-cis-heptenyl)furan
A solution of 35.8 g. of 2,5-dihydro-2,5-dimethoxy-2-(3'-oxopropyl)furan (Example 2) in 150 ml. of dimethylsulfoxide was added during 20 minutes at 17°-20° C. to a stirred solution of the Wittig reagent [(E. J. Corey, et al., J. Am. Chem. Soc., 91, 5675 (1969)] prepared from 18.5 g. of 57% sodium hydride dispersion, 98 g. of 4-carboxybutyltriphenylphosphonium bromide, and 590 ml. of dimethylsulfoxide. The deep red solution was stirred at ambient temperature for 60 minutes, and then the dimethylsulfoxide was distilled from the mixture in a bath at 55° C. in vacuo. The resulting sludge is partitioned between water and ethyl acetate. The aqueous phase is acidified to pH 6.0, saturated with sodium chloride, and extracted with 3:2 diethyl ether:petroleum ether. The extract is washed with brine, dried over magnesium sulfate, and concentrated to give an oil, ν max 1700 (carboxylic acid group) and 1015 cm - 1 (dimethoxydihydrofuran group).
EXAMPLE 4
Preparation of 9,12-dioxo-5-cis-dodecenoic acid
To a stirred solution of 4.92 g. of sodium acetate in 40 ml. of water was added a solution of 2.70 g. of 2,5-dihydro-2,5-dimethoxy-2-(7'-carboxy-3'-cis-heptenyl)furan (Example 3) in 50 ml. of 3:2 dioxane:water. The resulting stirred solution was treated during 5 minutes with 15.6 ml. of 1.6M aqueous titanium trichloride at 25° C. The dark mixture was stirred for 30 minutes, diluted with brine and ethyl acetate, and filtered through Celite. The aqueous phase of the filtrate is extracted with ethyl acetate. The combined organic phases are washed with brine, dried over magnesium sulfate, and concentrated to give an oil, pmr (CDCl 3 ) 2.75 (--CH 2 CH 2 -- group) and 9.86 δ (aldehyde group).
EXAMPLE 5
Preparation of 2-(6'-carboxy-2'-cis-hexenyl)cyclopent-2-en-1-one
A solution of 226 mg. of 9,12-dioxo-5-cis-dodecenoic acid (Example 4) in 10 ml. of 0.60N sodium hydroxide was allowed to stand at room temperature for 60 minutes. The solution was acidified with 4N HCl, saturated with sodium chloride and extracted with ethyl acetate. The extract is washed with brine, dried over magnesium sulfate, and concentrated. The residue is purified by chromatography on silica gel to give an oil, pmr (CDCl 3 ) 2.95 (1'-hydrogen atoms) and 7.35 δ (3-hydrogen atom).
EXAMPLE 6
Preparation of 2-(6'-carboxy-2'-cis-hexenyl)-3-hydroxycyclopent-4-en-1-one
To a stirred solution of 6.90 g. of sodium dihydrogen phosphate monohydrate and 3.55 g. of disodium hydrogen phosphate in 125 ml. of water and 115 ml. of 3:2 dioxane:water was added a solution of 6.76 g. of 2,5-dihydro-2,5-dimethoxy-2-(7'-carboxy-3'-cis-heptenyl)furan (Example 3) in 10 ml. of 3:2 dioxane:water. The resulting solution, pH 6.2, containing 9,12-dioxo-5cis,10-cis-dodecadienoic acid is heated at 45° C. for 45 hours. The course of the reaction is observed by workup as below of small aliquots and examination by thin layer chromatography and pmr. The reaction solution is worked up when the intermediate 9,12-dioxo-5-cis,10-cis-dodecadienoic acid (Example 10) is completely consumed. The solution is poured into 250 ml. of brine containing 7.5 ml. of 4N HCl and extracted with ethyl acetate. The extract is washed with brine, dried over magnesium sulfate, and concentrated. The residue is purified by column chromatography on silica gel to provide an oil, ν max 3370 (hydroxy group), 1710 (carbonyl groups), and 1595 cm - 1 (conjugated olefin group); pmr (CDCl 3 ) 4.70 (carbinolic hydrogen atom) and 7.53 δ (4-hydrogen atom).
EXAMPLE 7
Preparation of 2-(6'-carboxy-2'-cis-hexenyl)-4-hydroxycyclopent-2-en-1-one
A solution of 2.00 g. of 2-(6'-carboxy-2'-cis-hexenyl)-3-hydroxycyclopent-4-en-1-one (Example 6) and 3.77 g. of sodium carbonate in 89 ml. of water is allowed to stand at room temperature for 24 hours. The solution is acidified with 4N HCl, saturated with sodium chloride, and extracted with ethyl acetate. The extract is washed with brine, dried over magnesium sulfate, and concentrated to give an oil, pmr (CDCl 3 ) 4.95 (carbinolic hydrogen atom) and 7.19 δ (3-hydrogen atom).
EXAMPLE 8
Preparation of 4-carboxy-2-methylbutyltriphenylphosphonium bromide
A stirred solution of 61.3 g. of (R)-5-bromo-4-methylpentanoic acid [J. S. Dalby et al., J. Chem. Soc., 1962, 4387], 92.0 g. of triphenylphosphine, and 160 ml. of acetonitrile is refluxed for 96 hours. The solution is cooled until crystallization begins and then diluted with 750 ml. of diethyl ether to complete the precipitation. The salt is obtained by filtration and is dried in vacuo at 75° C., m.p. 151°-165° C.
EXAMPLE 9
Preparation of 2-(6'-carboxy-4'-methyl-2'-cis-hexenyl)-4-hydroxycyclopent-2-en-1-one
A solution of 5.01 g. of 2,5-dihydro-2,5-dimethoxy-2-(3'-oxopropyl)furan (Example 2) in 10 ml. of dimethylsulfoxide is added during 10 minutes at 18°-20° C. to a stirred solution of the Wittig reagent prepared from 2.57 g. of 57% sodium hydride dispersion, 14.1 g. of 4-carboxy-2-methylbutyltriphenylphosphonium bromide (Example 8), and 90 ml. of dimethylsulfoxide. The deep red solution is stirred at room temperature for 16 hours and then the dimethylsulfoxide is distilled from the mixture in vacuo from a bath at 65° C. The resulting sludge is stirred with water at 0° C. for 30 minutes, and the resulting insoluble triphenylphosphine oxide is removed by filtration.
The aqueous filtrate containing 2,5-dihydro-2,5-dimethoxy-2-(7'-carboxy-5'-methyl-3-cis-heptenyl)furan is treated with 23.9 g. of sodium dihydrogen phosphate monohydrate, the mixture is diluted with 80 ml. of dioxane, and the resulting solution containing 9,12-dioxo-4-methyl-5-cis,10-cis-dodecadienoic acid is heated at 45° C. for 66 hours. The stirred solution is treated during 5 minutes with 21 ml. of concentrated sulfuric acid and this solution is heated at 65° C. for 16 hours. The solution is cooled, saturated with sodium chloride, and extracted with ethyl acetate. The extract is washed with brine and extracted with sodium bicarbonate solution. The aqueous extract is acidified with 4N hydrochloric acid, saturated with sodium chloride, and extracted with ethyl acetate. This extract is washed with brine, dried over magnesium sulfate, and concentrated. The residue is purified by column chromatography on silica gel to provide an oil, ν max 3370 (hydroxy group), 1710 (carbonyl groups), and 1595 cm - 1 (conjugated olefin group); pmr (CDCl 3 ) 0.96 (doublet, methyl group), 4.95 (carbinolic hydrogen atom), and 7.19 δ (3-hydrogen atom).
EXAMPLE 10
Preparation of 9,12-dioxo-5-cis,10-cis-dodecadienoic acid
A stirred solution of 1.35 g. (5.0 mmoles) of 2,5-dihydro-2,5-dimethoxy-2-(7'-carboxy-3'-cis-heptenyl)furan (Example 3) in 25 ml. of tetrahydrofuran:water (85:15) is heated to 45° C. during 15 minutes. To the solution is added 0.60 g. of acetic acid and this solution is heated at 45° C. for 24 hours. The solution is diluted with brine and extracted with diethyl ether. The extract is washed with brine, dried over magnesium sulfate, and concentrated to give an oil.
Separation of the product is accomplished by thin layer chromatography on silica gel with heptane:ethyl acetate:acetic acid (60:40:2) to give an oil, pmr (CDCl 3 ) 10.2 δ (doublet, J=7 cps, aldehyde group). The compound gives a characteristic green spot, Rf = 0.29, when developed with the above chromatography system and sprayed with 2,4-dinitrophenylhydrazine reagent.
Also obtained from the reaction and chromatography is the 5-cis,10-trans isomer, pmr (CDCl 3 ) 9.82 δ (quartet, J=2 and 6 cps, aldehyde group). The compound gives a characteristic orange spot, Rf = 0.34, when developed with the above chromatography system and sprayed with 2,4-dinitrophenylhydrazine reagent.
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This disclosure describes novel 2,5-dihydro-2,5-dialkoxyfuran derivatives useful as intermediates for the preparation of the natural prostaglandins and their congeners.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for the separation of mixtures and is particularly useful in separating a fluid from a solid contained therein. The apparatus is well suited for the separation of blood plasma or serum from the blood cellular and particulate matter phase. In many laboratory and clinical situations, it is desired to separate a solid or semi-solid fraction of a mixture from a liquid fraction of the mixture. This may be accomplished in a number of fashions, with one of the most efficient being the use of an apparatus which is inserted into a sample containing tube to physically separate the liquid from the solid fraction of the mixture. The present invention provides such an apparatus which is capable of separating the liquid from the solid fraction of a mixture by the insertion of the apparatus into a sample containing tube. After the separation has been effected, a self-sealing portion of the apparatus is withdrawn from the sample containing tube as a contamination free, shippable container having the sample of the liquid collected contained therein. Remaining behind in the collection tube is the piston member which effectively seals the sample containing tube, providing a contamination free, sealed disposal means for the contaminating solid contained in the sample containing tube.
2. Description of the Prior Art
As is well known, the market place is replete with fluid separators, many of which are adapted to specialized purposes and useable only for those purposes. U.S. Pat. No. 3,586,064 shows an apparatus for the collection of blood wherein a hollow central body is closed at both ends by pierceable elastomeric seals. The seals are pierced by respective needles, so that when the device is inserted into a collection tube, one of the needles allows the liquid to flow into the interior of the hollow tube, while the other needle provides a vent to atmosphere. When sufficient sample has been collected, the atmosphere vent needle is withdrawn and the septum seals itself. Thereafter, the apparatus is withdrawn from the collection tube and the second needle is withdrawn, providing a self-sealing container for the collected sample.
U.S. Pat. No. 3,837,376 shows a similar apparatus wherein both ends of the collecting apparatus are exposed to the atmosphere while the liquid sample is being forced into the collection apparatus, but in this case, only one needle is used whereby the needle has two vents to be disposed within the interior of the collection apparatus. During the collection operation, liquid flows from the sample containing tube through the needle, into the hollow body through the lower one of the two vents. After the fluid has been collected in the lower portion of the collection apparatus, both ports are again free of fluid and atmospheric communication through the needle vents is established with the interior of the sample containing tube. This facilitates the removal of the collection apparatus from the sample containing tube without interference of so-called vacuum lock problems.
A similar device is shown in U.S. Pat. No. 3,983,037 wherein a flexible walled hollow tube, closed at both ends, is penetrated at one end by a needle-like structure. The end of the needle-like structure which terminates inside the collection apparatus is attached to a filter so that fluid passing through the needle-like structure from the sample containing tube is filtered before it passes into the interior of the collection apparatus. To employ this device, the collection apparatus is compressed to form a partial vacuum on the interior. The needle-like portion protruding from the closed end of the collection apparatus is inserted under the surface of the fluid to be collected, and the pressure on the collection apparatus is released, thereby causing the fluid in the sample containing tube to be drawn up into the needle, passed through the filter, and be collected on the interior of the collection apparatus.
U.S. Pat. No. 3,693,804 shows a pressure differential sampling device wherein the collection apparatus consists of a hollow body portion having one end closed by a piston filter assembly wherein a filter is fitted within a piston structure, and the piston filter structure is fitted within the hollow body of the collection apparatus. To employ the device, the assembly is forced into a sample containing tube so that the liquid is forced through the filter device into the interior of the hollow body portion of the collection apparatus. When sufficient sample has been collected, the collection apparatus is tilted sharply within the sample containing tube to break the seal therebetween and allow withdrawal of the entire apparatus.
In a similar device, U.S. Pat. No. 4,057,499, shows a blood collection apparatus comprising a hollow body tube having a piston member inserted into one end thereof. The piston member is generally bell-shaped with the narrowest portion of the bell structure being inserted into the hollow-body member. The piston contains a filter member through which passes fluid to be collected. In the upper end of the bell-shaped piston member is a one-way valve which allows the fluid to flow through the filter material and into the interior of the hollow body member of the collection apparatus. The composite piston member has a laterally extending flange which sealingly engages the interior wall of the sample containing tube while the collection apparatus is being forced into the sample tube to collect the fluid contained therein. Upon withdrawal of the entire collection apparatus, the flange of the piston folds over itself so that an upper radially grooved portion of the flange moves from its up position into a downward position, thereby breaking the seal between the flange member and the interior walls of the sample containing tube.
Many related fluid collection devices are known. For example, see U.S. Pat. Nos. 3,687,296, 3,850,174, 3,875,012 and 3,931,815.
SUMMARY OF THE INVENTION
A number of problems have been evident in these prior art devices. One of the major problems is that when the collection apparatus is withdrawn from the sample containing tube, the bottom of the collection apparatus is contaminated with the material contained in the tube. This material, especially in medical circumstances, may contain pathogens or toxins which should not be exposed to the laboratory environment. Additionally, another major problem exists in that the removal of the collection apparatus leaves an open sample containing tube which is similarly disadvantageous from a contamination or spillage standpoint in a laboratory.
The instant invention contemplates a fluid collection apparatus for the separation of a mixture including an elongate, thin walled, transparent, hollow body member which is closeable at both ends. Disposed at one end of the hollow body is a self-sealing septum. Disposed adjacent the septum is a closure means which includes a composite piston member having a laterally extending flange portion of a greater diameter than the diameter of the hollow body so that the flange portion extends past the outer edge of the hollow body. A central passageway extends through the body of the composite piston and allows communication with piercing means on the innermost end of the composite piston. Disposed within the central passageway is a filter element to effectively prohibit the passage of solid material which is mixed with the fluid fraction in the mixture from passing into the interior space in the hollow body. The composite piston member is configured so that it will be maintained as part of the hollow body assembly while the collection apparatus is being inserted into a sample collection tube. As the collection apparatus is forced into the sample collection tube, fluid in the mixture is forced through the filter element contained in the passage means and is vented to the interior of the hollow body. When sufficient sample has been collected, the path of travel of the collection apparatus is reversed. Upon such reversal, the composite piston assembly detaches itself from the collection apparatus by withdrawing the piercing means through the self-sealing septum and remaining behind in the sample containing tube with the composite piston. This composite piston assembly effectively seals the sample containing tube so that no contaminating material is exposed to the laboratory. The septum contained within the hollow body seals itself upon removal of the piercing means, typically a needle, from it, and thereby seals at one end the collected fluid within the hollow body. The other end of the hollow body is then sealed by closure means, such as a snap-on cap, to form a shippable, contamination free fluid collection apparatus, according to the present invention. It is an object of the present invention to provide an apparatus for the collection of fluids in a mixture which is of simple and sturdy design, which can be inserted into a sample containing tube, and which can be withdrawn without contaminating the exterior portion of the apparatus.
Another object of the present invention is to provide a simple, reliable apparatus which is useful not only for the collection of a sample in a non-contaminated container, but also contains means to seal the sample containing tube and thereby maintain any contaminating or hazardous materials therein.
A further object of the present invention is to provide an apparatus which is very simple in design and composed of minimal parts which can be reaily and economically manufactured and assembled.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objects and advantages will become readily apparent to one skilled in the art from reading the following detailed description of the present invention, when considered in light of the accompanying drawings, in which:
FIG. 1 is an exploded sectional perspective view of a fluid collection apparatus embodying the salient features of the present invention;
FIG. 2 is an enlarged sectional view of the assembled fluid collection apparatus illustrated in FIG. 1;
FIGS. 3a through 3c illustrate a schematic representation of the steps necessary to operate the apparatus illustrated in FIGS. 1 and 2; and
FIG. 4 is an elevational, partially sectional view of a modified form of the apparatus illustrated in FIGS. 1 and 2.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 and 2, the present invention is embodied in an apparatus for the collection of a fluid contained in a mixture, usually a liquid and a solid. The apparatus is well suited for the separation of blood plasma or serum from the cellular and particulate phase of centrifuged blood. There is shown a fluid collection apparatus 10 in the form of an elongate, thin walled, transparent, hollow body 12. A septum 14 is adapted to be inserted into one end of the hollow body 12. The septum 14 is typically cylindrical in shape and formed of a self-sealing plastic or rubber material. The septum 14 may be provided with an internally formed cavity 15 closed at the inner end thereof by a web portion 17. A composite piston 16 is formed to fit into the hollow body 12 and abut the septum 14. The composite piston 16 includes a unitary body 18 having at its outermost face a central passageway 20 which extends through most of the length of the unitary body 18 and terminates at the point of beginning of piercing means 22. The piercing means 22 is usually a plastic or steel needle. In the embodiment shown in FIGS. 1 and 2, the piercing means 22 is in the form of a hollow plastic needle which is blunt-nosed at the distal end 24. Along the length of the piercing means 22 and immediately below the distal end 24 are two vents 26 and 28 which allow fluid flow into the hollow body 12 from the exterior of the apparatus. A filter element 30 is disposed within the central passageway 20. The filter element 30 is usually a porous, plastic plug which restricts the flow of a solid through the central passageway 20 and piercing means 22 and into the interior of the hollow body 12, but will allow fluid flow through the same path. The outermost end of the composite piston 16 includes a peripherally extending flange 32 which serves to sealingly engage the inner walls of a sample containing tube into which the fluid collection apparatus 10 is inserted, as will be described in detail hereinafter. A snap-on closure 34 is formed to close the uppermost or first end of the hollow body 12 and is removed to employ the apparatus 10.
As shown in FIG. 2, the apparatus 10 is closed at one end by placing the snap-on closure 34 on the uppermost end of the apparatus 10. The filter element 30 is formed so that it will fit snugly within the central passageway 20. Alternatively, the filter element 30 may be secured in the central passageway 20 with a suitable adhesive. Usually, the piercing means 22 is integral with the unitary body 18 of the composite poston 16. When the piercing means 22 is formed of a plastic material, the entire composite piston 16, except for the filter element 30, can be formed in a single mold in a one step molding operation. After the filter element 30 is secured within the central passageway 20, the entire composite piston assembly 16 is typically inserted into the lowermost end of the hollow body 12 and pushed inwardly until the uppermost end of the composite piston 16 abuts the lowermost face of the septum 14. The piston 16 is formed so that the uppermost surface of the flange 32 engages the lowermost portion of the hollow body 12. The piercing means 22 penetrates and passes through the cavity 15 and the web portion 17 of the septum 14 and provides fluid communication between the exterior and the interior of the hollow body 12.
In the embodiment of the invention shown in FIGS. 1 and 2, the septum 14 can be pre-pierced to facilitate the insertion of the blunt-nosed plastic needle. Also, the flange 32 is beveled in shape to facilitate insertion of the apparatus 10 into a sample containing tube and to maintain the composite piston 16 in an upright position in the sample containing tube.
FIGS. 3a through c show the steps necessary to utilize the invention described in FIGS. 1 and 2.
In FIG. 3a, there is shown the assembled fluid collection apparatus 10 having the hollow body 12, the composite piston 16, with its unitary body 18, piercing means 22, flange 32 and filter element 30. The apparatus 10 is inserted into a sample containing tube 36, having an open end 38, a closed end 40, and a mixture contained therein comprising a solid fraction 42 and a fluid fraction 44. FIG. 3a shows the apparatus 10 poised just above the sample containing tube 36, ready to be inserted therein. As the apparatus 10 is inserted into the sample containing tube 36, the flange 32 of the composite piston 16 engages the inner wall 46 of the open end 38 of the sample containing tube 36. As the apparatus 10 is forced downwardly into the bore of the sample containing tube 36, the fluid 44 therein is forced through the filter element 30 and through the piercing means 22 and is collected as it flows from the vents 26 and 28 on the piercing means 22 into the hollow body 12.
After the fluid 44 is collected, the path of travel of the apparatus 10 is reversed. The piercing means 22 is withdrawn from the septum 14 due to the flange 32 being securely engaged to the inner wall 46 of the sample containing tube 36. The withdrawal of the hollow body 12 causes the web portion 17 of the septum 14 to automatically seal and thereby form a self-sealed fluid container, the outer surface of which is essentially contamination free due to the fact that no part of the exterior surface of the hollow body 12 or septum 14 has come in contact with any fraction of the solid 42 which may be a contaminant.
After the hollow body 12 and septum 14 portion of the assembly 10, is withdrawn from the tube 36, the composite piston 16, due to the flange 32 engaging the inner wall 46 of the tube 36, remains behind to seal the solid 42 within the tube 36. This forms a contamination free disposal vessel for the disposal of the solid. Many times the solid is a biological fluid, such as blood solids for example, which may contain contaminating materials which one would not want to be exposed to in the laboratory.
Another embodiment of the invention is shown in FIG. 4. The apparatus 48 embodied in FIG. 4 has an elongate, thin walled, transparent, hollow body 50 which is closed at its uppermost end by a screw type closure 52, having the closure 52 fitted with internal threads to engage external threads 54 on the exterior surfaces of the uppermost end of the hollow body 50. A setum 56 is disposed proximate the lowermost end of the hollow body 50. The septum 56 is formed of a self-sealing material, to be described in detail hereinafter. A composite piston 58 is also fitted into the lowermost portion of the hollow body 50. The composite piston 58 comprises a unitary body 60 having a central passageway 62 extending therethrough. At the uppermost end of the composite piston is piercing means 64 which is adapted to pierce the septum 56. Communication between the exterior and the interior of the hollow body 50 is provided through the hollow bore 66 and the central passageway 62. The piercing means 64 is usually a metal needle in this embodiment, with a rigid hollow body 67 and an internal hollow bore 66. A filter element 68 is disposed within the central passageway 62 of the composite piston 58, and a flange 70 extends from the unitary body 60.
The invention embodied in FIG. 4 differs from the invention embodied in FIGS. 1 and 2 in that the closure means 52 at the uppermost end is a threaded closure means; the flange 70 is not beveled; and the piercing means 64 is a stainless steel needle with a single bore 66, not a pair of side vents like 26 and 28.
In the preferred embodiment shown in FIGS. 1 and 2, the hollow body 12 is clear, rigid material such as a plastic or glass. A plastic is preferred and cellulose acetate butyrate tubes having an outside diameter of 11 millimeters, an inside diameter of 10 millimeters and a length of about 100 millimeters have proved satisfactory. The septum 14 is made of a self-sealing elastomeric material such as silicone rubber. The filter element 30 is a porous, plastic material which is dimensionally stable and rigid so that it may be formed into a cartridge shape to be inserted into the central passageway 20.
Generally, a 50 micron average pore size is adequate for use with most samples of biological origin. The pore size of the filter element 30 may be adjusted to meet any sample characteristics so long as the material meets the dimensional stability and compatability requirements above.
The composite piston body 18 is made of a rigid, dimensionally stable plastic, such as polyethylene. The snap-on closure 34 is also of a plastic but usually a flexible plastic like vinyl plastisol. When a plastic needle is employed as the piercing means 22, usually it is formed as an integral part of the unitary body 18 and is thus of the same composition, in this case polyethylene.
In the case of the invention embodied in FIG. 4, the screw type closure 52 is of a plastic composition, typically a rigid polyethylene. The piercing means 64 is a metal needle, usually stainless steel. All other components are the same as those specified for the preferred embodiment shown in FIGS. 1 and 2.
The septum 56 in the embodiment shown in FIG. 4 need not be pre-pierced or have a cavity and web construction, since the metal needle used easily pierces the septum 56. Also, it is to be recognized that, the plastic needle need not have two side vents 26 and 28, one will serve well in the apparatus. The two vent configuration does show the advantage of being more easily molded than does the single side vent configuration.
In any case, other suitable materials may be used so long as they conform to any standards needed in regard to rigidity, dimensional stability, or chemical inertness to the sample. For example, the snap-on closure is usually made of a flexible vinyl plastisol but could also be made of a flexible polyethylene should the needs of the user require. Since the apparatus may be readily employed to separate a reaction precipitate from a reaction supernatant fluid, solvent resistant plastic, glass, or metal components may be used where needed.
The apparatus of the invention is well suited to the separation of the liquid or fluid fraction of blood from the solid or semi-solid fraction thereof. In such use, the blood to be sampled must be initially subjected to centrifugation. If the apparatus is used with whole blood, some cellular debris or whole cells may pass through the filter element and be collected along with the fluid fraction of the sample. Typically, whole blood is placed in a sample containing tube and centrifuged to precipitate the blood solids from the supernatant fluid. The fluid is plasma, if an anticoagulant is added; and the cellular matter is simply precipitated. The fluid is serum when no anticoagulant is added and a unitary clot is formed as the semi-solid precipitate. In either case, the whole blood is typically centrifuged prior to the use of the apparatus.
An important feature of the invention is that essentially only the lowermost face of the composite piston 16 and the interior surfaces of the closure 34, the hollow body 12, and the septum 14 are exposed to any contamination from the sample. This results in a relatively clean, contamination free surface for the outer surfaces of the closure 34, the hollow body 12, and the septum 14, and the uppermost portion of the composite piston 16. Therefore, any contaminating matter in the sample is held on the interior of the closure 34, the hollow body 12, and the septum 14, or at the bottom of the sample containing tube which is closed by the composite piston 16 and thereby provides a clean, shippable container for the fluid fraction; and a clean, easily disposable container for the solid fraction of the sample.
While a preferred and alternative embodiment of the present invention has been illustrated and described, it is understood that various modifications may be resorted to without departing from the scope of the appended claims.
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A fluid collection apparatus is disclosed which is useful in separating blood serum or plasma from blood cellular and particulate matter. The apparatus includes an elongate hollow body having a self-sealing septum sealingly disposed within one end thereof and a piston having an axially projecting hollow piercing element adapted to pierce the septum and provide communication with the interior of the hollow body. The piston includes a laterally extending flange for sealing engagement with the interior of a container for containing the mixture to be treated. After the hollow body and the associated piston assembly is inserted into the container the flange of the piston is engaged with the inner wall of the container causing the composite piston apparatus to remain in and seal a sample within the container.
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CROSS-REFERENCES TO RELATED APPLICATIONS
This application claims the priority of German Patent Application, Serial No. 103 37 551.1, filed Aug. 14, 2003, pursuant to 35 U.S.C. 119(a)-(d), the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates, in general, to a pressure measuring device for an injection molding machine.
Nothing in the following discussion of the state of the art is to be construed as an admission of prior art.
A typical injection molding machine includes an injection mold and an injection unit for injecting a shot of plastic melt into the injection mold. The injection unit is provided with a rotary drive to rotate a plasticizing screw for advancing plastic in a barrel while being plasticized, and an injection drive or thrust generator for axially moving the screw to thereby inject the shot into the adjacent injection mold. In order to measure the thrust applied on the plasticizing screw by the injection drive for determining the melt pressure of the plastic melt in the barrel, the use of a load detector has been proposed. Examples include European Patent specification EP 0 350 872 B1, U.S. Pat. Nos. 5,206,034 and 6,247,913. The load detector is hereby positioned in the drive train between the injection drive and the plasticizing screw and includes a force transmitting element, which elastically deforms when being subjected to the thrust, and a pickup device for measuring the deformation. Conventional load detectors suffer shortcomings because the force transmitting element is realized in the form of a separate mechanical and fairly expensive precision structure and because the integration of the measuring device inside the injection unit so that a replacement is only difficult to implement and time-consuming. When the load detector is placed directly in the driveshaft, which is coupled with the plasticizing screw, in the shaft region between driveshaft bearing and the plasticizing screw, the supply of auxiliary energy and the transmission of the measuring value is difficult to implement between the part that conjointly rotates with the driveshaft and the stationary part of the load detector.
It would therefore be desirable and advantageous to provide an improved pressure measuring device for an injection molding machine to obviate prior art shortcomings and to attain high precision in measurement while being simple in structure and reliable in operation.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, a pressure measuring device for an injection molding machine having a plasticizing screw operated by a rotary drive and an injection drive, includes a load detector having a deformation zone which forms part of a transmission member of the injection drive and has a reduced cross section and which elastically deforms in response to a driving force acting on the transmission member, and a sensor for measuring a change in shape of the deformation zone.
The present invention resolves prior art problems by integrating the elastically deformable force transmitting element of the load detector in the transmission member of the injection drive so that the force transmitting element is axially upset or compressed when subjected to the thrust of the injection drive and thereby shortened and at the same time widened. The transmission member may hereby be a screw driveshaft having a cylindrical shaft portion constructed of reduced diameter to define the deformation zone and positioned between the plasticizing screw and a bearing for the driveshaft. As an alternative, the injection drive may be a spindle drive, with the transmission member being part of the spindle drive and having a cylindrical portion of reduced diameter to define the deformation zone.
The portion of the transmission member that is reduced in cross section is easy to make, highly unlikely to fail because the axial force is applied evenly, and is able to change its shape commensurate with an applied load (thrust). The measuring range of a measuring device according to the present invention can be easily expanded or reduced through change of the effective measuring distance.
According to another feature of the present invention, the sensor may be constructed to measure in a contactless manner a change in shape of the deformation zone, such as a change in length and/or thickness of the deformation zone. The sensor may hereby be a laser scanner or an inductive pickup device. This configuration is especially advantageous, when the deformation zone is provided in a rotating transmission member because of the absence of complicated rotating arrangements for transmitting auxiliary energy and measuring signals.
According to another aspect of the present invention, an injection molding machine includes a plasticizing screw, a rotary drive for rotating the screw, an injection drive having a force transmission member for moving the screw in an axial direction and a load detector having a deformation zone which forms part of a transmission member of the injection drive and has a reduced cross section and which elastically deforms in response to a driving force acting on the transmission member, and a sensor for measuring a change in shape of the deformation zone.
BRIEF DESCRIPTION OF THE DRAWING
Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which:
FIG. 1 is a longitudinal section of a main portion of an injection unit of an injection molding machine provided with a pressure measuring device in accordance with a first embodiment of the present invention; and
FIG. 2 is a longitudinal section of a main portion of an injection unit of an injection molding machine provided with a pressure measuring device in accordance with a second embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Throughout all the Figures, same or corresponding elements are generally indicated by same reference numerals. These depicted embodiments are to be understood as illustrative of the invention and not as limiting in any way. It should also be understood that the drawings are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted.
Turning now to the drawing, and in particular to FIG. 1 , there is shown a longitudinal section of a main portion of an injection unit forming part of an otherwise not shown injection molding machine. The injection unit includes a plasticizing barrel 4 which houses a plasticizing screw 5 which is connected to a driveshaft 3 . The screw 5 is rotated by a rotary drive 2 and moved in axial direction by an injection drive or thrust generator 1 . The combination of injection drive 1 and rotary drive 2 is received in a housing 6 and acts on the driveshaft 3 to thereby transmit the rotational and axial movements to the screw 5 .
The injection drive 1 is constructed as spindle drive comprised of a rotatable but axially immobile threaded nut 8 , which is operated e.g. by a belt drive 7 , and a threaded shaft 9 which carries the nut 8 and is mounted to the housing 6 in such a manner as to be movable in axial direction but constraint from rotating. Thrust is applied by the threaded shaft 9 via a pivot bearing 10 onto the driveshaft 3 and from there is transmitted to the plasticizing screw 5 .
The rotary drive 2 includes a journal 12 which is rotatably mounted in the housing 6 and driven by a belt pulley 11 . The driveshaft 3 is linked in fixed rotative engagement to the journal 12 via a sliding fit 13 which allows an axial displacement driveshaft 3 in correspondence to the thrust of the injection drive 1 . In the filling and metering phase, the plasticizing screw 5 is caused to rotate by the rotary drive 2 and, independently thereform, is moved translationally in axial direction in the injection phase by the injection drive 1 . The axial force applied upon the plasticizing screw 5 is hereby ascertained by a load detector, generally designated by reference numeral 14 , as a measure for the melt pressure of plastic melt in the barrel 4 .
As shown in FIG. 1 , the load detector 14 includes a deformation zone 15 which is formed integral with the driveshaft 3 in the form of a cylindrical shaft portion 16 which is reduced in diameter and positioned between the plasticizing screw 5 and the pivot bearing 10 for the driveshaft 3 . In other words, the cylindrical shaft portion 16 is positioned in a region of the driveshaft 3 which is free of any bearings in order to effectively eliminate errors in measurement as a consequence of bearing friction or other interferences. The load detector 14 further includes a pickup device for measuring elastic changes in shape of the shaft portion 16 (deformation zone 15 ), i.e. changes in length and/or thickness of the shaft portion 16 when subjected to the thrust force. The pickup device operates in a contactless manner and is implemented in the form of a laser scanner which includes a laser transmitter 18 and a laser receiver 19 . Both the laser transmitter 18 and the laser receiver 19 are mounted to a sleeve-like attachment 20 of the threaded shaft 9 and operatively connected to an evaluation circuit 22 via auxiliary energy and measuring signal lines 21 . The laser scanner 18 , 19 operates at high cycle rate of up to 400 Hz and its measuring range can easily be adjusted by means of the evaluation circuit 22 . The attachment is closed by a lid 23 to protect the load detector 14 and the deformation zone 15 of the pressure measuring device against external influences while allowing easy access. Suitably, the attachment 20 is detachably secured to the threaded shaft 9 .
Referring now to FIG. 2 , there is shown a longitudinal section of a main portion of an injection unit of an injection molding machine provided with a pressure measuring device in accordance with a second embodiment of the present invention. Parts corresponding with those in FIG. 1 are denoted by identical reference numerals and not explained again. The description below will center on the differences between the embodiments. In this embodiment, provision is made for a load detector having a deformation zone 15 , which forms an integral part of the threaded shaft 9 and is defined by a cylindrical portion of reduced diameter. The load detector further includes a contactless sensor in the form of an inductive pickup device 24 which detects length changes of a plunger 25 in relation to a measuring coil 26 and converts the measured quantity into corresponding measuring signals for input in the evaluation circuit 22 . The plunger 25 is hereby secured in the deformation zone 15 to an inside wall of the cylindrical portion of the threaded shaft 9 at a distance to the measuring coil 26 which is secured to an opposite inside wall of the cylindrical portion.
While the invention has been illustrated and described in connection with currently preferred embodiments shown and described in detail, 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. The embodiments were chosen and described in order to best explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims and includes equivalents of the elements recited therein.
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A pressure measuring device for an injection molding machine having a plasticizing screw operated by a rotary drive and an injection drive includes a load detector having a deformation zone which forms part of a transmission member of the injection drive and is of reduced cross section, and a sensor. The deformation zone elastically deforms in response to a driving force acting on the transmission member, with the sensor measuring a change in shape of the deformation zone.
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FIELD OF THE INVENTION
The present invention relates to telecommunications in general, and, more particularly, to teleconferencing.
BACKGROUND OF THE INVENTION
A teleconference is a meeting between two or more participants who are not at the same place at the same time. Teleconferencing is a low-cost alternative to getting large groups of invitees in a single place at the same time for the purpose of having a meeting. The best known example of a teleconference is a conference call with more than two people participating in the call. These teleconferences can have upwards of several hundred people and can last for several hours. An alternative to having a teleconference would be to get these people to the same place at the same time, which is often prohibitive.
Even when participants to a conference call are calling in from the places of their choosing, often only a portion of a teleconference is useful to a participant. Because teleconferences can last for hours at a time, it is wasteful for a participant to wait for the small portion of the teleconference that is useful to her. Furthermore, invitees to teleconferences sometimes cannot attend due to conflicts or other reasons.
Therefore, what is needed is a teleconferencing system that enables people to optimize their time with respect to a teleconference to which they have been invited, without some of the disadvantages in the prior art.
SUMMARY OF THE INVENTION
The present invention allows an invitee to a conference call, who is not present on at least part of the call, to have the call monitored in his or her absence. In accordance with the illustrative embodiment of the present invention, the invitee is offered the opportunity to review, ahead of or during the call, one or more electronic documents that are pertinent to the call. In reviewing each document, the invitee can specify one or more pointers for the purpose of identifying positions throughout the content of the document. The pointer-identified positions correspond to portions of the document, as well as possibly to events to occur during the call, which are relevant to the invitee.
During the call, when a relevant portion of an electronic document, as identified by a pointer, has been reached or is soon to be reached, the system of the illustrative embodiment transmits a message to the invitee who is not on the call. The message might provide: i) information that is presented about the relevant portion such as a response to a question specified by the invitee; ii) a command or contacting information that enables the invitee to join the call; or iii) a time at which the relevant portion is expected to be presented during the call.
For example, when a set (or “deck”) of presentation slides has been uploaded for a conference call, invitees to the call can scroll through the set and mark a slide for the purpose of receiving i) an alert during the call or ii) a response to comments marked on the slide. The marking made by the invitee can indicate when the invitee is to be alerted to join the call. The alert can be sent to the invitee via Short-Message Service, Instant Messaging, email, or another means. Alternatively, the annotations can result in the automatic launch of a teleconferencing application for the purpose of joining the endpoint of the invitee to the conference call that is already in progress.
In addition, the system of the illustrative embodiment is able to modify the calendars of an invitee or invitees, such that the time that the invitee is advised to join the call, or is joined to the call, is trimmed to the time that a topic of interest is expected to be discussed on the call. The expected time can be based on the meeting agenda, the electronic documents, and/or the number of comments already accumulated.
Similarly, the invitee can annotate slides or portions of an electronic document with comments that he or she would like to have addressed during the conference call. The annotations can be in text, voice, or audio/video format, depending on the format or formats that would be appropriate for the medium of the conference call in question. During the call, each response is summarized or recorded when the corresponding comment is presented to the participants, and then the response is sent to the invitee or invitees who posted the comment in the first place. In some embodiments, if several invitees have related questions, a threaded question-and-answer transcript is presented to all of those invitees who have such related questions.
By using the disclosed technique of supporting partial conference call attendance, contextual posting of questions, and alerting of other conference call events, an invitee is able to participate in a selected portion or portions of a conference call. Alternatively, if the invitee has a limited number of questions, the invitee is able to receive the responses without having to join the call at all.
The illustrative embodiment of the present invention comprises: receiving, at a data-processing system, i) an electronic document, wherein the electronic document comprises a plurality of portions, and ii) a first pointer from a telecommunications endpoint of a first user, wherein the first pointer references a position within one of the portions in the plurality; presenting at least a subset of the portions in the plurality during a conference call, to at least a telecommunications endpoint of a second user; and transmitting a message to the telecommunications endpoint of the first user, based on the presenting of the portion that comprises the position referenced by the first pointer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a schematic diagram of teleconference system 100 in accordance with the illustrative embodiment of the present invention.
FIG. 2 depicts an overview of the conference call processing performed by teleconference bridge 104 , in accordance with the illustrative embodiment of the present invention.
FIG. 3 depicts the tasks associated with performing the processing that occurs before the conference call begins.
FIG. 4 depicts the tasks associated with performing the processing that occurs during the conference call.
FIG. 5 depicts conference agenda 500 , a first example of the content of an electronic document.
FIG. 6 depicts slide set 600 , a second example of the content of an electronic document.
FIG. 7 depicts response set 700 , which corresponds to comments contained in an electronic document related to slide set 600 .
DETAILED DESCRIPTION
FIG. 1 depicts a schematic diagram of teleconference system 100 in accordance with the illustrative embodiment of the present invention. System 100 comprises telecommunications endpoints 101 - 1 through 101 -J, wherein J is an integer greater than one; telecommunications network 102 ; private branch exchange (PBX) 103 ; and teleconference bridge 104 , interconnected as shown.
Telecommunications endpoint 101 -j, where j has a value between 1 and J, inclusive, is a device that is capable of handling a telephone call for its user. Endpoint 101 -j can be a cellular phone, a conference phone (i.e., “speakerphone”), a deskset, a computer with or without a resident softphone, or some other type of telecommunications appliance that is capable of exchanging voice signals. Endpoint 101 -j is able to call, or to be called by, another endpoint or device within teleconference system 100 . For example, in order to participate in a conference call, endpoint 101 -j is able to dial a telephone number that routes to teleconference bridge 104 .
Some of endpoints 101 - 1 through 101 -J are endpoints that are tied to a private-branch exchange (PBX), such as desksets in an office enterprise network for which telecommunications service is enabled by private-branch exchange 103 . For example, endpoints 101 - 1 , 101 - 3 , and 101 - 4 as depicted are PBX endpoints that route through PBX 103 in order to place or receive a call, such as a conference call that involves bridge 104 . In any event, it will be clear to those skilled in the art how to make and use telecommunications endpoint 101 -j.
Telecommunications network 102 provides the connectivity among endpoints 101 - 1 through 101 -J, and enables the transport and control of communications signals between two or more endpoints per call. The communications signals convey bitstreams of encoded media, such as audio, video, and so forth. To this end, network 102 comprises one or more interconnected data-processing systems such as switches, servers, routers, and gateways, as are well-known in the art. For example, network 102 comprises private-branch exchange 103 and teleconference bridge 104 .
In accordance with the illustrative embodiment, network 102 comprises an Internet Protocol-based (IP-based) network, as is known in art, for the purpose of transporting voice signals. Although network 102 in the illustrative embodiment comprises a Voice-over-IP (VoIP) service provider's network, network 102 could alternatively or additionally comprise another type of network such as the Internet, some other type of IP-based network, or some other type of packet-based network, such as the Public Switched Telephone Network, as those who are skilled in the art will appreciate.
Teleconference bridge 104 is a data-processing system, such as a server or switch, which enables the users of multiple endpoints to communicate with each other during a conference call, for one or more concurrent calls. Bridge 104 receives audio signals from endpoints that are participating on a conference call, mixes those signals together, and transmits the mixed signals back to the endpoints.
Bridge 104 also performs at least some of the tasks of the illustrative embodiment, which are described below and with respect to FIGS. 2 through 4 . It will be clear, however, to those skilled in the art how to make and use alternative embodiments of the present invention in which a data-processing system different than bridge 104 performs the tasks of the illustrative embodiment. For example, in some alternative embodiments, private-branch exchange 103 might perform some or all of the tasks described herein or another data-processing system not shown might perform some or all of the tasks.
Furthermore, it will be clear to those skilled in the art, after reading this specification, how to make and use embodiments of system 100 in which the monitoring of a conference call is performed concurrently on behalf of one or more invitees of that call, for each of one or more calls being monitored.
FIGS. 2 through 4 depict flowcharts of salient tasks that are related to the performing of conference call processing, by teleconference bridge 104 , in accordance with the illustrative embodiment of the present invention. As those who are skilled in the art will appreciate, some of the tasks that appear in the flowcharts can be performed in parallel or in a different order than that depicted. Moreover, those who are skilled in the art will further appreciate that in some alternative embodiments of the present invention, only a subset of the depicted tasks are performed.
FIG. 2 depicts an overview of the conference call processing performed by teleconference bridge 104 .
At task 201 , bridge 104 performs the processing that occurs before the conference call begins. The subtasks associated with task 201 are described below and with respect to FIG. 3 .
At task 202 , bridge 104 initiates the conference call in well-known fashion.
At task 203 , bridge 104 performs the processing that occurs during the conference call. The subtasks associated with task 203 are described below and with respect to FIG. 4 .
FIG. 3 depicts the tasks associated with performing the processing that occurs before the conference call begins.
At task 301 , bridge 104 receives one or more electronic documents in objects such as computer files. In accordance with the illustrative embodiment, each electronic document comprises electronic media content. Examples of electronic documents include, but are not limited to:
i. word processing documents, represented in computer files with extensions such as *.doc, *.txt, etc.; ii. spreadsheet documents, represented in computer files with extensions such as *.xls, etc.; and iii. graphics-software documents, represented in computer files with extensions such as *.ppt, *.vsd, etc.
The electronic documents are viewable or editable via compatible application software. Each electronic document can be provided from a different user, such as a person giving a presentation, or some or all of the documents can come from a centralized source. Each electronic document comprises a plurality of portions, such as the line items in conference agenda 500 or each slide in slide set 600 , which are described with respect to FIGS. 5 and 6 , respectively
In some embodiments, each portion of a first electronic document might be associated with its own electronic document. For example, each agenda item listed in conference agenda 500 might have an associated electronic document such as a slide presentation. However, it will be clear to those skilled in the art, after reading this specification, how to make and use alternative embodiments in which each portion has more than one associated electronic document, or does not have any associated electronic document.
At task 302 , bridge 104 notifies one or more of the conference call invitees of the call that is to take place. Alternatively, a participant of the call, such as the moderator or host, can notify the invitees.
At task 303 , bridge 104 notifies one or more of the conference call invitees of the availability of electronic documents that are associated with the conference call. Alternatively, a participant of the call, such as the moderator or host, can notify the invitees. In some embodiments, the invitees are notified of where they can find the one or more electronic documents.
At task 304 , bridge 104 receives information from one or more invitees related to the electronic documents made available at task 303 . In particular, bridge 104 receives one or more pointers from each of one or more telecommunications endpoints, or other nodes. Each pointer references a position within one of the portions of an electronic document. In some embodiments, the position might identify a specified event related to the conference call, such as a particular topic on the list of agenda items or a particular part of a presentation. For example, a first invitee might have marked conference agenda 500 with pointer 501 - 1 that references a position within the conference agenda list, where the position corresponds to the phrase “Product Features,” which is a specified event on the list of conference agenda items. In some embodiments the pointers are received separately, while in other embodiments a modified version of the electronic document that contains the pointers is received.
In accordance with the illustrative embodiment, bridge 104 is able to use each pointer for more than one purpose, such as i) providing advance notification to an invitee or ii) joining an invitee to a call. In some alternative embodiments, however, bridge 104 can allow an invitee to identify a particular portion of a document by using multiple pointers, and then bridge 104 uses each pointer for a different purpose. For example, in addition to there being a “main” pointer to identify a beginning position within a document, there can be an “advance” pointer which bridge 104 uses to determine when to notify the invitee, and there can be an “end” pointer to indicate the end position of a relevant portion in a document.
Bridge 104 is able to receive one or more comments from each of one or more endpoints, or other nodes. Each comment is associated with content within a portion of the electronic document. For example, a second invitee might have marked slide set 600 with pointer 602 - 1 and included comment 603 - 1 , which is a question that the invitee would like answered by the person giving the presentation. In some embodiments the comments are received separately, while in other embodiments a modified version of the electronic document that contains the comments is received.
Although the illustrative embodiment features the pointers and/or comments being received prior to the conference call, it will be clear to those skilled in the art, after reading the specification, how to make and use alternative embodiments in which bridge 104 is able to receive pointers and/or comments during the call.
Task execution proceeds to task 202 , at which the conference call is initiated. Depending on when bridge 104 receives information from each invitee, task 202 might be performed shortly thereafter (e.g., minutes, hours, etc.) or the task might be performed at a longer time thereafter (e.g., days, weeks, etc.).
FIG. 4 depicts the tasks associated with performing the processing that occurs during the conference call. During the time interval that corresponds to the execution of the depicted tasks, bridge 104 carries on the conference call with at least one endpoint of a participating user of teleconference system 100 , aside from the one or more invitee users who are not present for at least part of the call. The conference call itself is made up of a plurality of specified events, such as events that are specified on a list of agenda items as shown in agenda 500 .
At task 401 , bridge 104 notifies the invitees that the conference call has started. In accordance with the illustrative embodiment, this is accomplished through one or more of various text-oriented means including, while not being limited to, Short-Message Service, Instant Messaging, email, and so forth. Alternatively, bridge 104 can notify the invitees via audio or video media.
In some embodiments, bridge 104 also presents the moderator or host of the call with an overview of all invitees who are not part of the call initially, along with the pointers that they have specified. During the call, this overview can be updated as some invitees join to become call “participants,” and as some participants drop from the call and resume their status as non-participating “invitees.”
At task 402 , bridge 104 presents one or more portions of the electronic documents to the participants of the conference call, in well-known fashion. For example, based on having received commands from a presenter's endpoint, bridge 104 advances one or more times to a next, or specified, slide or page in the electronic document.
In some alternative embodiments, the portions of content that are presented during a call are not embodied in a collection of discrete documents, but are retrieved from any combination of one or more records, documents, messages, and/or other sources of content in an electronic storage system.
At task 403 , bridge 104 determines an expected time of a specified event that has been identified by a pointer received at task 304 . For example, on behalf of an invitee, the bridge might determine when a particular slide is expected to be presented. In some embodiments, the expected time can be based on i) the one or more scheduled times that are indicated by agenda 500 , such as scheduled time 502 - 1 , or ii) the time at which the expected time is determined, such as the current time in the conference call. Alternatively, the expected time can be based on some other aspect of agenda 500 , the electronic documents, and/or the number of comments already accumulated.
In some alternative embodiments, the expected time can be determined at the scheduled time of the specified event. For example, referring to agenda 500 , if the “Product Features” presentation is scheduled to start at 9:15 AM, as indicated by element 502 - 1 , bridge 104 can determine the expected time at which the presentation is expected to begin, in the event that the overall conference call is running behind schedule.
At task 404 , bridge 104 determines whether the conference call is over or not. If the call is not over, task execution proceeds to task 405 . Otherwise, task execution ends.
At task 405 , bridge 104 determines whether a portion that corresponds to a pointer received at task 304 is currently being presented. If not, task execution proceeds to task 406 . Otherwise, task execution proceeds to task 407 .
At task 406 , bridge 104 transmits a message to the endpoints of one or more invitees. By transmitting the message, the bridge is alerting the invitee that the part of the conference call that is of interest to him is going to be discussed. In some embodiments, the transmitting of the message, or message itself, is based on the expected time determined at task 403 and/or the amount of advance notification the recipient invitee might have specified. In some other embodiments, the transmitting of the message is based on an advance notice position in the document having been reached, as identified by the “advance” pointer described with respect to task 304 .
As those who are skilled in the art will appreciate, the transmitting of the message can serve various purposes. The message itself might comprise the expected time of when the discussion will take place. Instead of the expected time, the message might comprise an estimated difference in time between document positions that correspond to the “advance” and “main” pointers described above and with respect to task 304 . The estimated difference in time can be determined, for example, either manually by the moderator or host, or automatically based on the rate of progress through the previous portions of the document. Alternatively, the message can comprise a command to join the endpoint of the invitee to the conference call at or around the expected time determined.
In some embodiments, the moderator or host of the call is able to control the transmission of a notification message to one or more invitees—for example, those invitees who have specified the same portion or similar portions of the electronic document. The moderator or host might track which portions of which documents an invitee is interested in, note the amount of advance notification that the invitee needs, and transmit the message accordingly.
After task 406 , execution then proceeds back to task 402 .
At task 407 , bridge 104 optionally records a response to a comment provided at task 304 , based at least on a portion being presented that is marked by a pointer received earlier from an invitee. For example, bridge 104 can record a response beginning at a slide that is being presented for which the invitee had left a comment.
At task 408 , bridge 104 transmits a message to the endpoints of one or more invitees, based at least on a portion being presented that is marked by a pointer received earlier. In some embodiments, bridge 104 might transmit the message in order to alert the invitee that the current slide (or portion) is being presented, so that the invitee can join the part of the call that is of interest to him. Alternatively, the message might comprise a command to join the endpoint of the invitee to the conference call.
In some other embodiments, the transmitting of the message, or the message itself, can be based on the comment for which a response was provided at task 407 . In this case, the bridge can notify the invitee that his comment has been responded to, possibly also providing a network location at which the response can be found. The message can comprise the response itself, so that the invitee can be provided with the response directly.
In any event, task execution then proceeds back to task 402 .
As those who are skilled in the art will appreciate, the transmission of the message at task 406 or task 408 can be accomplished through one or more of various text-oriented means including, while not being limited to, Short-Message Service, Instant Messaging, email, and so forth. Alternatively, bridge 104 can transmit either type of message via audio or video media. Furthermore, either message can comprise a status of the conference call, while in some other embodiments either message can serve to modify the calendar of an invitee or invitees, such that the time that the invitee is advised to join the call, or is joined to the call, is trimmed to the time that a topic of interest is expected to be discussed on the call.
In some alternative embodiments, bridge 104 can notify an invitee that a portion of a document was skipped over on the call. For example, where there are multiple pointers specified for a given portion of the document, bridge 104 can transmit a first type of notification when the document positions corresponding to the “main” and “end” pointers—or the “advance”, “main”, and “end” pointers—are skipped over. Bridge 104 can transmit other types of notifications, depending on which combination of pointers (i.e., “advance”, “main”, “end”) are either skipped or not skipped during the call.
FIG. 5 depicts conference agenda 500 , which comprises i) one or more pointers 501 - 1 through 501 -P, and ii) one or more scheduled times 501 - 1 through 501 -S, wherein P and S are positive integers. Although both P and S as depicted are equal to one, the value for each of P and S can be different from that depicted, as well as different from each other.
Although the teleconferencing system of the illustrative embodiment features an electronic document comprising a conference agenda (i.e., agenda 500 ), it will be clear to those skilled in the art, after reading this specification, how to make and use alternative embodiments in which a different number of agenda documents are used, or in which none at all are used.
FIG. 6 depicts slide set 600 , which comprises one or more presentation portions 601 - 1 - 1 through 601 - 1 -R, wherein R is a positive integer. In accordance with the illustrative embodiment, a single portion corresponds to the content associated with one presentation slide. However, it will be clear to those skilled in the art, after reading this specification, how to make and use embodiments in which a single portion corresponds to the content associated with only part of one presentation slide, more than one presentation slide, or a different type of “page” than a slide, such as a page in a text file, a cell or worksheet in a spreadsheet, and so forth.
Although the teleconferencing system of the illustrative embodiment features an electronic document comprising a slide presentation (i.e., slide set 600 ), it will be clear to those skilled in the art, after reading this specification, how to make and use alternative embodiments in which a different number of presentation documents are used, or none at all are used.
Present as part of presentation portions 601 - 1 - 1 through 601 - 1 -R are pointers 602 - 1 through 602 -C, wherein C is a positive integer, as described above and with respect to task 304 .
FIG. 6 further comprises one or more comment portions 601 - 2 - 1 through 601 - 2 -R, which corresponds to the “scratchpad” area of slide set 600 , or in a separate electronic document, which is used by the invitees to provide comments, as described with respect to task 304 . Present as part of comment portions 601 - 2 - 1 through 601 - 2 -R are comments 603 - 1 through 603 -C, wherein C is a positive integer, as described above and with respect to task 304 . In some embodiments, comments 603 - 1 through 603 -C correspond to pointers 602 - 1 through 602 -C.
FIG. 7 depicts response set 700 , which comprises one or more response portions 601 - 3 - 1 through 601 - 3 -R, wherein R is a positive integer. In accordance with the illustrative embodiment, each response portion corresponds to a presentation portion as described above and with respect to FIG. 6 . Present as part of response portions 601 - 3 - 1 through 601 - 3 -R are responses 701 - 1 through 701 -C, wherein C is a positive integer, as described above and with respect to task 407 . In some embodiments, responses 701 - 1 through 701 -C correspond to comments 603 - 1 through 603 -C.
It is to be understood that the disclosure teaches just one example of the illustrative embodiment and that many variations of the invention can easily be devised by those skilled in the art after reading this disclosure and that the scope of the present invention is to be determined by the following claims.
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A method is disclosed which allows an invitee to a conference call, who is not present on at least part of the call, to have the call monitored in his or her absence. The invitee is offered the opportunity to review, ahead of the call, one or more electronic documents that are pertinent to the call. The invitee can specify one or more pointers for the purpose of identifying positions that correspond to portions of the document that are relevant to the invitee. When a relevant portion of an electronic document has been reached or is soon to be reached during the call, a message is transmitted to the absent invitee. Additionally, the invitee can annotate slides or portions of an electronic document with comments that he or she wants addressed during the conference call. A message is subsequently transmitted to the invitee, providing responses to the comments left earlier.
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This application is a National Stage completion of PCT/FR2009/001199 filed Oct. 13, 2009, which claims priority from French patent application Ser. No. 08/05666 filed Oct. 14, 2008.
FIELD OF THE INVENTION
The present invention relates to a heat generator comprising at least one thermal module composed essentially of a magnetocaloric element arranged for being crossed by a heat transfer fluid and two hot and cold chambers arranged on each side of the magnetocaloric element and each containing a means for displacing the heat transfer fluid through the magnetocaloric element, a magnetic arrangement arranged for creating a magnetic field variation in the magnetocaloric element so as to alternately create in the magnetocaloric element a heating cycle and a cooling cycle, and a device for driving the displacement means according to a reciprocating movement in the concerned chamber for displacing the heat transfer fluid on either end of the magnetocaloric element in synchronization with the magnetic field variation in order to create and then maintain a temperature gradient between the two opposite ends of the magnetocaloric element.
BACKGROUND OF THE INVENTION
Magnetic refrigeration technology at ambient temperature has been known for more than twenty years and the advantages that it provides in terms of ecology and sustainable development are widely acknowledged. Its limits in terms of useful calorific output and efficiency are also well known. Consequently, all the research undertaken in this field is directed at improving the performance of such a generator, by adjusting the various parameters, such as the magnetization power, the performance of the magnetocaloric element, the heat exchange surface between the heat transfer fluid and the magnetocaloric elements, and the performance of the heat exchangers, etc.
The French patent application no. 07/07612 by the applicant describes a magnetocaloric generator in which the thermal energy generated by magnetocaloric elements is exchanged with a heat transfer fluid that is displaced through the magnetocaloric elements by circulation means. These circulation means are in the form of pistons that are driven with reciprocating movement by a control cam having a specific cam profile.
This generator however presents a disadvantage that is inherent to driving these pistons. In fact, this drive is subjected to the wear of the components in contact, that is, the cam profile and the pistons, which can result in a premature degradation of the generator efficiency. Moreover, it poses problems of sealing between the piston sleeves and the drive mechanism.
SUMMARY OF THE INVENTION
The present invention aims to overcome these disadvantages by proposing a magnetocaloric generator of a simple construction having a reduced number of constitutive components, in which, on the one hand, the risk of sealing loss between the chamber in which these means of fluid circulation move and the means of driving them are greatly limited and on the other hand, whose service life is increased and efficiency is preserved.
For this purpose, the invention concerns a heat generator with a drive device that comprises a closed fluid circuit establishing a fluidic connection between the hot and cold chambers in which the flow of fluid is driven by a suction and discharge device, and at least one switching interface synchronized with the magnetic arrangement for alternatively connecting each hot and cold chamber on the suction and discharge sides of the suction and discharge device and inversely.
The heat generator thus comprises a single device for driving the means of displacing the heat transfer fluid. The use of the switching interface allows avoiding the use of switching valves or other similar devices and thus facilitates the design of the heat generator. Besides, the integration of this interface in the heat generator, according to the invention, enables reducing the dimensions of the generator.
The heat generator according to the invention is designed for exchanging thermal energy with one or more external user circuits (heating, air-conditioning, tempering, etc.), being connected to them through a heat exchanger, for example.
According to the invention, the maneuvering fluid and the heat transfer fluid can be the same.
The switching interface can preferably comprise at least one switching plate mounted in the heat generator and inserted between one of the hot or cold chambers of the thermal module and a distribution flange fitted with a suction circuit and a discharge circuit which are connected respectively to the suction and discharge sides of the suction and discharge device.
The switching plate can comprise run-through passages which provide fluidic communication between the hot and cold chambers and the suction and discharge circuits of the distribution flange.
In a preferred embodiment of the invention, the heat generator may present a circular structure comprising several thermal modules arranged in a circle around a central axis.
In this configuration, it may comprise two switching interfaces, each with a switching plate, the switching plates and the corresponding distribution flanges may also be circular and the suction and discharge circuits of the distribution flanges may be in the form of two concentric grooves formed on their face in front of the switching plates.
In a first variant, the magnetic arrangement may be concentric to the central axis and driven in rotation around the axis, and the switching plates and the magnetic arrangement may be rotationally driven around the central axis by the same actuator. This configuration allows making the heat generator more compact.
In a second variant, the magnetic arrangement may be fixed and formed of electromagnets that are connected to an electrical power source and the switching plates may be rotationally driven around the central axis by a specific actuator.
In addition, the switching plates may be identical and mounted with an angular offset between each other so that each thermal module is connected, on the one side, at the level of its hot or cold chamber, to a run-through passage of a switching plate connected to the suction circuit of a distribution flange and, on the other side, at the level of its cold or hot chamber, to a run-through passage of the other switching plate connected to the discharge circuit of the other distribution flange.
By integrating identical switching plates, the manufacturing cost of the generator can be reduced.
With regard to the magnetic arrangement, it may comprise alternating magnetized zones and non-magnetized zones and the run-through passages of the switching plates may be arranged according to the alternation, for displacing the heat transfer fluid in each thermal module from the hot chamber to the cold chamber when the magnetocaloric element is not subjected to a magnetic field and from the cold chamber to the hot chamber when the magnetocaloric element is subjected to a magnetic field.
In addition, according to the invention, all the hot chambers and all the cold chambers may be contained in a housing that can form a heat exchanger.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention and its advantages will be better revealed in the following description of an embodiment given as a non limiting example, with reference to the enclosed drawings in which:
FIG. 1 is an exploded perspective view of a heat generator according to the invention,
FIG. 2 is a longitudinal sectional view of the heat generator represented in FIG. 1 ,
FIG. 3 is a perspective view of a distribution flange of the heat generator represented in FIG. 1 ,
FIG. 4 is a perspective view of a switching plate of the heat generator represented in FIG. 1 and
FIG. 5 is a lateral elevation view of the heat generator represented in FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the enclosed figures, the heat generator 1 is of an approximately circular configuration. It comprises several thermal modules 2 arranged in a circle around an axis A and each containing a magnetocaloric element 3 arranged between the two hot 4 and cold 5 chambers and two means 6 for displacing a heat transfer fluid through the magnetocaloric element 3 . These means of displacement are in the form of pistons 6 (see FIG. 2 ) arranged in the hot 4 and cold 5 chambers, between the bottom of these chambers and the hot end 9 or cold end 10 of the magnetocaloric element 3 .
The bottom of the hot 4 or cold 5 chambers means the end of the chamber opposite the magnetocaloric element 3 .
The magnetocaloric element 3 allows for the flow of the heat transfer fluid and it may be made up of one or more magnetocaloric materials. It has open fluid passages that may be formed of the pores of porous material, mini or micro-channels machined in a solid block or obtained by assembling superposed grooved plates, for example.
The heat generator 1 also contains a magnetic arrangement 7 with magnetized zones and non-magnetized zones, driven in rotation by an actuator (not represented) so as to submit each magnetocaloric element 3 to a magnetic field variation and create alternately, in each magnetocaloric element 3 , a heating cycle and a cooling cycle. The pistons 6 are displaced synchronously with the magnetic arrangement 7 so as to circulate the heat transfer fluid alternately to each side of each magnetocaloric element 3 and to generate and maintain a temperature gradient between the two opposite ends 9 and 10 of each magnetocaloric element 3 .
According to the invention, the pistons 6 are displaced by a drive device 8 containing a maneuvering fluid integrated in a closed circuit connecting the bottoms of the hot 4 and cold 5 chambers and that may or may not be different from the heat transfer fluid. Preferably, this maneuvering fluid of pistons 6 and the heat transfer fluid are identical so that possible leakage does not impede the operation of the heat generator 1 .
The maneuvering fluid of pistons 6 is driven by a single continuous suction and discharge device 11 . This device operates continuously and has a suction side 14 and a discharge side 15 to suck and discharge the maneuvering fluid continuously. Such a device may be a centrifugal pump, for example. It displaces the pistons 6 alternately in both directions of circulation by means of the two switching interfaces 12 , each having a switching plate 121 , 122 which respectively and alternately connects the bottom of the hot chambers 4 or cold chambers 5 to the suction circuits 141 and the discharge circuits 151 provided in the two corresponding distribution flanges 16 and 17 of the fluid. These circular distribution flanges 16 and 17 are arranged on each side of the thermal modules 2 and are fitted with connecting nozzles 20 , 21 which facilitate their connection to the suction and discharge device 11 . For this purpose, the connecting nozzle 20 of distribution flanges 16 and 17 connects their suction circuit 141 to the suction side 14 of the suction and discharge device 11 while the connecting nozzle 21 of the distribution flanges 16 and 17 connects their discharge circuit 151 to the discharge side 15 of the suction and discharge device 11 .
These distribution flanges 16 and 17 cooperate with the switching plates 121 and 122 , which are also circular and driven in rotation by the same actuator as that of the magnetic arrangement 7 . They comprise run-through passages 18 and 19 for establishing communication alternately between the bottom of the hot chambers 4 and cold chambers 5 of the thermal modules 2 and the corresponding suction circuits 141 and discharge circuits 151 of the distribution flanges 16 and 17 . The suction circuits 141 and the discharge circuits 151 of the distribution flanges 16 and 17 are formed by two concentric grooves (see FIG. 3 ) produced on their face and located in front of the switching plates 121 and 122 in the mounted position of the heat generator 1 and respectively facing the run-through passages 18 and 19 (see FIG. 4 ).
Of course, another configuration of the suction circuits 141 and the discharge circuits 151 can be contemplated without departing from the scope of protection of the invention. In this case, the switching plates 121 and 122 are also adapted for being able to co-operate with the circuits.
Similarly, in a configuration not represented, the magnetic arrangement may be realized with electromagnets that are subject to a variable electrical field and a specific actuator may be provided for rotating the switching plates 121 and 122 .
Because of this, by considering for example the thermal module 2 represented on the top part of the FIG. 2 , the heat transfer fluid contained within is displaced from right to left in the figure. For this purpose, a run-through passage 19 of the switching plate 122 connected to the discharge circuit 151 of the corresponding distribution flange 17 has positioned itself to face the cold chamber 5 while a run-through passage 18 of the switching plate 121 connected to the suction circuit 141 of the corresponding distribution flange 16 has positioned itself to face the hot chamber 4 of the same thermal module 2 . The heat transfer fluid has thus passed through the magnetocaloric element 3 of the thermal module 2 of the cold chamber 5 towards the hot chamber 4 , while the magnetic arrangement 7 was placed so as to subject the magnetocaloric element 3 to a magnetic field, inducing heating of the magnetocaloric element 3 . During the passage of the heat transfer fluid through the magnetocaloric element 3 , an exchange of heat has taken place between these and such that the fluid heated is up before reaching the corresponding hot chamber 4 .
In the next cycle, after rotation of the magnetic arrangement 7 and the switching plates 121 and 122 , the magnetocaloric element 3 of the thermal module 2 located in the top part of FIG. 2 will no longer be subject to a magnetic field and the fluid shall be displaced from left to right. For this purpose, the switching plates 121 and 122 will rotate so that a run-through passage 18 of the switching plate 122 connected to the suction circuit 141 of the corresponding distribution flange 17 will be positioned facing the cold chamber 5 while a run-through passage 19 of the switching plate 121 connected to the discharge circuit 151 of the corresponding distribution flange 16 will be positioned facing the hot chamber 4 of the same thermal module 2 . The heat transfer fluid will pass through the magnetocaloric element 3 of the thermal module 2 from the hot chamber 4 towards the cold chamber 5 , while the magnetocaloric element 3 cools down. The flow of the heat transfer fluid through the magnetocaloric element 3 will enable an exchange of heat between these which results in a cooling of the heat transfer fluid flowing towards the cold chamber 5 .
The bottoms of the hot chambers 4 and cold chambers 5 are preferably open and the switching plates 121 and 122 provide their sealing. For this purpose, a housing 23 may contain the hot chambers 4 and a housing 24 may contain the cold chambers 5 , and these housings 23 and 24 may each be fitted with a circular rim 13 which is designed for co-operating with the flank of the corresponding switching plate 121 or 122 for ensuring sealing between the switching plate 121 or 122 and the corresponding hot 4 or cold 5 chambers. A means of sealing such as a seal may also be placed between these components. Any other form of assembly and means of sealing may be envisaged.
These housings 23 and 24 are in contact with the hot 4 and cold 5 chambers and can therefore be used as heat exchangers.
In a variant not represented, a single housing may contain both hot 4 and cold 5 chambers as well as all the magnetocaloric elements 3 and comprise, at the level of each of its ends, the circular rim 13 . Besides, such a housing may be composed of two half shells assembled according to a longitudinal plane of the heat generator 1 .
In addition, the magnetocaloric elements 3 may also be integrated in a housing 22 , as shown in the enclosed figures.
In the embodiment represented, the switching plates 121 and 122 are identical. They are in the form of solid disks with pairs of run-through passages 18 , which are meant to be connected to the suction circuit 141 , made at the height of or in front of it in the mounted position of the heat generator 1 , and arranged alternately with pairs of run-through passages 19 which are meant for being connected to the discharge circuit 151 and made at the height of or in front of it in the mounted position of the heat generator 1 . The switching plates 121 , 122 are mounted in the heat generator 1 with an angular offset of 45°, this angle corresponding to the angle separating two consecutive magnetized zones of the magnetic arrangement 7 . Such an arrangement enables changing the displacement direction of the pistons 6 and thus that of the heat transfer fluid at the level of each magnetocaloric element 3 of each thermal module 2 in synchronization with the variation of a magnetic field acting on the magnetocaloric element 3 .
In other words, when the magnetocaloric element 3 of a thermal module 2 is subjected to a magnetic field and is heated, the switching plates 121 and 122 are arranged so as to drive the pistons 6 for displacing the heat transfer fluid from the cold chamber 5 to the hot chamber 4 in this thermal module 2 . Inversely, when this same magnetocaloric element 3 is no longer subjected to a magnetic field and is cooling down, the switching plates 121 and 122 are arranged so as to drive the pistons 6 for displacing the heat transfer fluid from the hot chamber 4 to the cold chamber 5 in this thermal module 2 .
The run-through passages 18 and 19 are constantly in fluidic relation with the suction circuits 141 and discharge circuits 151 . Thus, when a run-through passage 18 or 19 is facing a hot chamber 4 or a cold chamber 5 , it allows, by suction or discharge of the fluid, the displacement of the piston 6 located in this chamber.
Even though all the enclosed drawings illustrate a heat generator 1 with a single unit made up of an assembly of thermal modules 2 arranged in a circle around the central axis A, the invention also provides for the embodiment of a heat generator having a staged structure with several units. Such a configuration allows increasing the efficiency of the heat generator according to the invention.
Possibilities Of Industrial Application
This description shows clearly that the invention allows reaching the goals defined, that is to say it offers a heat generator 1 with a simple design and reduced dimensions limiting the number of moving parts for the circulation of the heat transfer fluid in the thermal modules 2 and resolving the problems of sealing due to the movement of the means for displacing the heat transfer fluid.
Such a heat generator 1 can be utilized in industrial as well as domestic applications, in the area of heating, air conditioning, tempering, cooling or others, at competitive costs and with reduced space requirements.
Furthermore, all parts making up this heat generator 1 can be manufactured according to reproducible industrial processes.
The present invention is not restricted to the example of embodiment described, but extends to any modification or variant which is obvious to a person skilled in the art while remaining within the scope of the protection defined in the attached claims.
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A heat generator comprising at least one thermal module comprising a magnetocaloric element crossed by a heat transfer fluid and two hot and cold chambers arranged on each side of the magnetocaloric element and containing a displacement device for directing the heat transfer fluid through the magnetocaloric element. A magnetic arrangement creates a magnetic field variation in each magnetocaloric element. A device for driving the displacement device, according to reciprocating movement in the concerned chamber, to displace the heat transfer fluid in synchronization with the magnetic field variation. The drive device contains a closed fluid circuit which connects the hot and cold chambers in which a working fluid is driven by a suction and discharge device. At least one switching interface is synchronized with the magnetic arrangement for alternately connecting each hot and cold chamber to suction and discharge sides of the suction and discharge device and inversely.
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BACKGROUND OF THE INVENTION
The invention relates to improvements in apparatus for treating running webs of paper, plastic material or the like. More particularly, the invention relates to improvements in apparatus which can be utilized to remove substances which are entrained by running webs by resorting to a gaseous fluid, particularly to remove films and/or droplets of moisture from freshly exposed and developed webs of photographic paper.
Published German patent application No. 20 56 571 discloses a demoisturizing apparatus wherein the moisture-carrying web is trained over a guide roll and advances past a nozzle which discharges a stream of compressed air.
Published German patent application No. 21 50 796 discloses an apparatus wherein a flattened portion of the moisture-carrying web is caused to advance past an air discharging nozzle. The orifice of the nozzle is located in a plate which is adjacent and parallel to the flattened portion of the running web. In order to enhance and optimize the demoisturizing action of air which issues from the nozzle, the width of the gap between the path of the flattened portion of the web and the plate for the orifice of the nozzle must be reduced to a minimum. If the web consists of exposed and freshly developed photographic paper, the pressure of air which is discharged by the orifice in the plate cannot exceed a certain maximum permissible value because any further rise of air pressure could entail damage to images on the exposed and developed web of photographic paper. On the other hand, if the width of the gap is increased above the minimum acceptable value while the pressure of air is maintained at a maximum permissible value, the velocity of air which reaches the adjacent surface of the running web is too low so that air merely shifts but does not disperse the liquid film on the running web. Atomization of the liquid film, and hence actual drying of photographic paper, takes place only when the width of the gap is maintained at an optimum value. Such width is less than is necessary to permit passage of spliced (overlapping) portions of successive webs of photographic paper and/or to permit passage of customary clamps which are used to separably couple the leaders of webs of photographic paper to entraining bands. Reference may be had to commonly owned U.S. Pat. No. 4,773,580 to Schweiger.
OBJECTS OF THE INVENTION
An object of the invention is to provide an apparatus which ensures the establishment of an optimum distance between the nozzle and the running web.
Another object of the invention is to provide an apparatus wherein the optimum width of the passage for the running web is established and maintained in a fully automatic way.
A further object of the invention is to provide an apparatus which can be installed in existing developing machines for webs of photosensitive material.
An additional object of the invention is to provide the apparatus with novel and improved means for determining the minimum width of the passage for advancement of the running web past the locus of impingement of a gaseous fluid.
Still another object of the invention is to provide an apparatus which permits the advancement of splices and/or clamps without affecting the accuracy and predictability of the cleaning and demoisturizing action.
A further object of the invention is to provide the apparatus with novel and improved means for varying the width of the passage for the running web.
Another object of the invention is to provide an apparatus which can be utilized with particular advantage for removal of impurities and/or moisture from running webs of freshly developed photographic paper.
SUMMARY OF THE INVENTION
The invention is embodied in an apparatus for removing entrained substances from running webs with a gaseous fluid, particularly for removing moisture from running webs of exposed and developed photographic paper. The improved apparatus comprises a web guiding member, a fluid discharging member adjacent the web guiding member and defining therewith a web-receiving passage of variable width, and means for supporting at least one of the members for movement relative to the other member in directions to vary the width of the passage.
The web guiding member can include an idler roll or a driven roll, and the web is preferably trained over the roll along an arc of not less than 90°, most preferably close to 180°. The passage is adjacent that portion of the web which is trained over the roll. The arrangement is preferably such that the roll is rotatable about a fixed axis and the fluid discharging member is movable relative to the roll. The apparatus further comprises means for conveying the web toward and away from the roll along a predetermined path having a first portion wherein successive increments of the web advance toward the roll in a first direction and a second portion wherein successive increments of the web advance away from the roll in a second direction (e.g., exactly counter to the first direction). The fluid discharging member is preferably movable relative to the roll in at least one of the first and second directions.
The web guiding member is preferably located at a level above the fluid discharging member, i.e., the roll is located above the passage for the web. The supporting means can include one or more springs and/or other suitable means for biasing the fluid discharging member upwardly toward the roll with a force which compensates for the weight of the fluid discharging member. The force which is applied by the biasing means can slightly exceed the weight of the fluid discharging member, i.e., the fluid discharging member then tends to rise toward the roll to thus reduce the width of the passage. Therefore, the apparatus preferably further comprises means for limiting the extent of movability of the fluid discharging member toward the roll so as to prevent physical contact between the web in the passage and the fluid discharging member. The limiting means can be provided on the roll and can include a flange at one axial end or a flange at each axial end of the roll.
A handle or other suitable means can be provided to move the fluid discharging member to a lower end position in which the width of the passage is sufficient to permit convenient threading of the web through the passage.
The fluid discharging member can include a lower portion (e.g., a stationary lower portion which is connected to a source of compressed air or another suitable gaseous fluid) and an upper portion which is movable relative to the lower portion toward and away from the web guiding member to thereby vary the width of the passage. The upper portion has at least one orifice (e.g., a single orifice in the form of an elongated slot which confronts and extends longitudinally of the passage) which directs fluid against the web in the passage.
The configuration of the passage is preferably such that its width decreases in the direction of advancement of successive increments of the running web into the passage toward the orifice in the upper portion of the fluid discharging member.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved apparatus itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain presently preferred specific embodiments with reference to the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic elevational view of a portion of a developing machine for webs of exposed photographic paper wherein the web which issues from the rinsing bath of the developing machine is cleaned and demoisturized in an apparatus embodying one form of the invention;
FIG. 2 is an enlarged view as seen in the direction of arrow II in FIG. 1 but showing a modified apparatus; and
FIG. 3 is a sectional view substantially as seen in the direction of arrows from the line III--III in FIG. 2.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring first to FIG. 1, there is shown a portion of a developing machine for webs 1 of exposed and freshly developed photographic paper. Successive increments of the web 1 are conveyed from a fixing bath (not shown) into a rinsing bath 3 in a vessel 4. The means for conveying the web 1 along a predetermined path includes a large roll 2 in the vessel 4 and a plurality of smaller rolls or pulleys 5. The rinsed web 1 is relieved of moisture in an apparatus which embodies one form of the present invention, and the demoisturized web is then caused to pass through a drier on its way to a cutting or severing station to be subdivided into discrete photographic prints in a manner not forming part of the present invention.
The improved web cleaning and demoisturizing apparatus comprises a web guiding member 7 in the form of an idler roll which is rotatable about a fixed axis, and a fluid discharging member 8 which is installed at a level below the roll 7 and at least a portion of which is movable up and down so as to move its gas-discharging orifice 9 nearer to or further away from that portion of the running web 1 which is trained over the lowermost portion of the peripheral surface of the roll 7. A certain percentage of moisture is removed from the running web 1 during advancement from the bath 3 toward the roll 7 over several pulleys 5 of the conveying means. A fixedly mounted standard air discharging nozzle 6 can be placed next to one of the pulleys 5 between the bath 3 and the roll 7 to remove certain impurities and/or a certain percentage of moisture ahead of the improved apparatus. The developing machine can comprise two or more nozzles 6, e.g., one for each pulley 5 upstream of the roll 7.
The pulleys 5 cooperate with the roll 7 in such a way that the web 1 is trained over the roll 7 along an arc well in excess of 90°, preferably close to or exactly 180°. The nozzle 9 of the gas discharging member 8 is oriented to discharge (arrow AA) a single stream or a row of streams of compressed gas (normally air) in parallelism with the axis of the roll 7 and in the general direction (arrow A) of advancement of successive increments of the running web 1 toward as well as in the general direction (arrow B) of advancement of successive increments of the web 1 away from the six o'clock position of the roll 7.
In accordance with a feature of the invention, at least a portion of at least one of the members 7, 8 is movable toward and away from the other member to thereby vary the width of the web-receiving passage 19 (see FIGS. 2 and 3) in the region of the nozzle 9. As mentioned above, the roll 7 of the apparatus of FIG. 1 is rotatable about a fixed (preferably horizontal) axis. The member 8 is supported and is movable upwardly by several springs 10 each of which is suspended from a stationary carrier 110 and is dimensioned and stressed to bias the member 8 upwardly with a force which at least matches the weight of the member 8, preferably with a force which slightly exceeds the weight of the member 8 so that the latter tends to move upwardly to an upper end position in which the width of the passage 19 is reduced to a minimum. The means for limiting the extent of movability of the member 8 toward the roll 7 includes two flanges 12 (see FIG. 2) which are installed at the axial ends of the roll 7 and ensure that the minimum width of the passage 19 suffices to prevent bodily contact between the running web 1 and the member 8.
A presently preferred embodiment of the improved apparatus is shown in FIGS. 2 and 3. The running web 1 is trained over the lower half of the roll 7 along an arc of exactly or very close to 180° (i.e., the direction (arrow A) of advancement of successive increments of the web toward the passage 19 is parallel to the direction (arrow B) of advancement of successive increments of the web away from the passage 19). The gas discharging member 8 has a stationary lower portion 15 which is connected with a source 116 of compressed gas by a flexible or rigid conduit 16, and an upper portion 13 which sealingly engages the lower portion 15 and is movable up and down under the bias of or against the opposition of two coil springs 10 as well as under the pressure of compressed gas in the member 8. The upper portion 13 of the member 8 has two stubs 17 which are connected to the lowermost convolutions of the respective springs 10, and these springs are suspended (at 18) from the fixed carrier 110. The upper portion 13 of the member 8 has an orifice 14 in the form of an elongated slot which extends in parallelism with the axis (of the shaft 11) of the roll 7 and discharges compressed gas against the underside of the web 1 at the six o'clock position of the roll 7. The width of the passage 19 decreases gradually in the direction of arrow A toward the orifice 14 to thereupon gradually increase in the direction of arrow B.
The bias of the springs 10 suffices to compensate for the weight of the movable portion 13 of the gas discharging member 8 as well as to urge the portion 13 upwardly with a relatively small force so that the portion 13 normally abuts the flanges 12 at the two axial ends of the roll 7. The flanges 12 may but need not rotate with the roll 7; in fact, the roll 7 need not rotate about its horizontal axis. The minimum width of the passage 19 is selected in such a way that, at a given pressure of gas which issues from the orifice 14, the gaseous fluid is capable of optimally cleaning and demoisturizing the web 1 in the passage 19 while the upper portion 13 of the member 8 abuts the flanges 12. At the same time, the springs 10 enable the upper portion 13 to yield (by moving downwardly in order to increase the width of the passage 19) so that a splice between overlapping end portions of two successive webs 1 can readily pass between the roll 7 and the member 8. The same holds true for customary clamps which are used in developing machines to drag the leader of the foremost web 1 of a series of spliced-together webs through various baths and thereupon into the drier of a developing machine. Reference may be had to aforementioned commonly owned U.S. Pat. No. 4,773,580.
The extent to which the flanges 12 project radially beyond the web-contacting peripheral surface of the roll 7 at least matches the thickness of a web 1 but can be less than the combined thickness of two webs. The aforediscussed configuration of the passage 19 (which narrows gradually in the direction of arrow A toward the orifice 14 and thereupon widens gradually in the direction of arrow B) is desirable and advantageous because this ensures predictable introduction of aforediscussed splices and/or clamps into the passage 19 and the advancement of such parts through and beyond the passage. A splice or a clamp simply pushes the upper portion 13 of the member 8 downwardly whereby the width of the passage 19 increases to be immediately reduced by the springs 10 as soon as the splice and/or the clamp has advanced beyond the orifice 14. Thus, the width of the passage 19 is automatically maintained at an optimum value (the upper portion 13 of the member 8 then abuts the flanges 12) in normal operation of the improved apparatus.
The lower portion 15 of the member 8 has an external shoulder defined by a base 20 and serving as a stop for the upper portion 13. The latter can be provided with a handle (not shown) which is actuated by hand or otherwise to move the portion 13 to a lower end position in which the width of the passage 19 is increased to a value which permits convenient threading of the leader of a web 1 or of a band which draws the web 1 through various baths of the developing machine. As a rule, the upper portion 13 of the member 8 will be moved against the stop of the base 20 by a suitable mechanism which becomes operative or which is actuated prior to threading of the leader of a web or a band through the passage 19. The stop of the base 20 can surround a part of or the entire lower portion 15.
When the width of the passage 19 is reduced to a minimum value (because the upper portion 13 of the member 8 abuts the flanges 12), the cleaning and demoisturizing operation of the improved apparatus is based on Bernoulli's hydrodynamic paradox according to which a subatmospheric pressure develops between the member 8 and the running web 1 in the passage 19. The development of subatmospheric pressure in the passage 19 entails that the member 8 is attracted toward the roll 7, but such attracting force is opposed by the force which is generated by the jet or jets of compressed gas issuing from the orifice 14. The force of outflowing compressed gas is balanced by the attracting force which develops as a result of the establishment of subatmospheric pressure in the passage 19.
It is desirable and advantageous to avoid stray movements (such as fluttering) of the web 1 during advancement past the nozzle 14. This is the reason that the web 1 is trained over the peripheral surface of the roll 7 along an arc well in excess of 90°, preferably at least close to 180°. An additional advantage of the apparatus which is shown in FIGS. 2 and 3 (wherein the web 1 is trained over the roll 7 along an arc of close to or exactly 180°) is that the fine mist of atomozed liquid which develops as a result of impingement of compressed gas upon the moisture-carrying underside of the running web 1 is not redeposited on but bypasses the running web downstream of the nozzle 14.
The apparatus can be modified by making the member 8 stationary and by mounting the web guiding member (roll 7) for movement toward and away from the member 8. Furthermore, it is possible to employ a member 7 which is movable toward and away from the member 8 which latter is movable (either in its entirety or in part) toward and away from the member 7. The illustrated embodiment is preferred at this time because it ensures that the web 1 can be conveyed along its path by a simple and reliable conveyor system (the illustrated conveyor system includes the roll 2 in the bath 3 and the pulleys 5 at least one of which is driven in a manner not forming part of the invention if the web 1 is not drawn by a belt or the like).
The springs 10 can be used jointly with or replaced by other biasing means (e.g., by pneumatic cylinder and piston units) which are designed to urge a portion of or the entire member 8 toward and normally against the flanges 12 with the aforediscussed force which at least matches the weight of the member 8 of FIG. 1 or the weight of the movable portion 13 of the member 8 of FIGS. 2 and 3.
In the apparatus of FIG. 1, the discharge end of the flexible conduit (not shown) which serves to connect the member 8 with a source of compressed gas is movable up and down with the member 8 when the latter is displaced under the action or against the opposition of the springs 10. The apparatus of FIGS. 2 and 3 is preferred at this time because the magnitude of the force with which the springs 10 urge the movable upper portion 13 of the member 8 against the flanges 12 is more predictable than in the apparatus of FIG. 1. The reason is that the part (lower portion 15) which is connected with the conduit 16 need not move up and down, i.e., the resistance which the portion 13 offers to upward movement under the bias of the springs 10 is the same at all times.
The minimum width of the passage 19 (when the upper portion 13 of the member 8 abuts the flanges 12) is selected in such a way that the jet or jets of gaseous fluid issuing from the orifice 14 not only displace but actually atomize (disperse) the liquid film at the underside of the running web 1. At the same time, the flanges 12 prevent the establishment of physical contact between the running web 1 and the upper portion 13 of the member 8.
The fact that the development of suction in the passage 19 is interrupted during passage of a splice and/or clamp is of no consequence. The springs 10 ensure that the movable upper portion 13 returns into abutment with the flanges 12 so that the aforediscussed optimal circumstances for removal of moisture from the running web 1 are reestablished in a fully automatic way.
The aforementioned mechanism which serves to move the portion 13 of the member 8' to its lower end position of engagement with the shoulder of the base 20 of the lower member 15 is preferably actuated in automatic response to starting of the developing machine to thus permit convenient threading of the leader of a web 1 or of an entraining band through the enlarged or widened passage 19 in a time-saving manner. The springs 10 then store energy and automatically return the upper portion 13 into engagement with the flanges 12 as soon as the mechanism is deactivated.
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 and specific aspects of the aforedescribed contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the appended claims.
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A running web of wet exposed and developed photographic paper which issues from a rinsing bath in a developing machine is caused to advance around a fixedly mounted guide roll and through a passage between the guide roll and the orifice of a combined cleaning and drying member which discharges compressed air against successive increments of the running web. The air discharging member is biased upwardly toward the roll to abut flanges which are provided at the ends of the roll and serve to determine the minimum width of the passage in such a way that the air discharging member cannot rise into physical contact with the web.
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FIELD OF THE INVENTION
[0001] This invention relates to firearms and more particularly to a magazine holder and a cycling holder, each allowing for quick and efficient cycling of a semi-automatic firearm with one hand.
BACKGROUND OF THE INVENTION
[0002] Semi-automatic, or self-loading, firearms are firearms that perform all the steps necessary to prepare the weapon to fire again after an initial firing, assuming that cartridges remain in the weapon's feed device or magazine. Typically, these steps include extracting and ejecting the spent cartridge case from the weapon's firing chamber, re-cocking the firing mechanism, and loading a new cartridge into the firing chamber. Although automatic weapons and selective firearms do the same tasks, semi-automatic firearms do not automatically fire an additional round until the trigger is released and re-pressed by the person firing the weapon. However, semi-automatic firearms still require the action to be cycled manually before the first shot and when a new magazine is inserted.
[0003] Considering a police officer who carries a semi-automatic firearm then under normal circumstances during the performance of their duties, the officer has free and full use of both hands for the drawing, loading, firing, unloading and clearing of their semi-automatic duty pistol. The training an officer receives on firearms handling and safety teaches them to load their pistol at the beginning of each duty shift. This involves removing the pistol from the duty holster, loading a magazine (sometimes called a clip) of ammunition into the pistol, cycling the pistol slide one time while using their primary hand (dominant hand) to hold the pistol grip then using their secondary hand to grip the sides of the pistol slide and move it in a rearward direction to manipulate a round out of the magazine and into the chamber or breach. This slide loading action can be accomplished using the secondary hand and either a “pinch grip”/“sling shot grip” at the rear end of the slide or an “overhand grip” over the top of the slide, behind the breach and pulling the slide mechanism rearward—then releasing the slide forward resulting in a chambered round and the pistol “in battery”. After the weapon is loaded for duty it is then placed back into the duty holster and secured.
[0004] If a weapon is drawn by the officer during the performance of their duties and is actually discharged, several things can occur. One, when the weapon functions properly, a round of the ammunition is fired and the projectile proceeds out of the muzzle of the weapon in the direction it is aimed at by the officer. The semi-automatic design of the pistol sends the slide back allowing another round to be chambered and ready to fire so long as there is ammunition in the properly seated magazine. Alternatively, there can be a problem such as the ammunition misfiring, or not firing, leaving an un-discharged round of ammunition in the chamber or breach of the weapon which must be cleared out before the weapon can be fired properly. This is referred to by terms such as “live trigger stoppage”, “phase one stoppage” and other terms indicating an unintended interruption of fire. To clear such a blockage, the officer must ensure the magazine is seated properly by tapping it with the support hand, cycle the slide of the weapon back to eject the non-fired round of ammunition and allow the weapon's action to load a fresh round of ammunition into the chamber or breach from the magazine. As described previously, this is a two-handed operation.
[0005] Another unintended interruption of fire that can occur is a “dead trigger stoppage”. This typically occurs when a round or casing fails to eject from the chamber due to faulty ammunition or a damaged extractor. A second round tries to feed into the chamber but is blocked by the initial round/casing that failed to eject. The pressure of the slide trying to fall forward into battery (but stopped by the “double feed”) seizes the pistol. As the extractor may not be able to properly grasp either round (the action can now only partially cycle), simply cycling the action will not clear the malfunction. A pistol in this state will not fire. In order to clear the pistol the magazine must be forcefully removed as pressure is holding the rounds in place. Ideally, the slide is placed in the locked back position releasing pressure on the double fed rounds. This allows the magazine to be stripped much easier. Once the magazine is stripped, the officer clears the port to ensure the chamber and magazine well are clear, then inserts a fresh magazine and cycles the action forward resulting in a fully loaded and ready (live round in chamber) pistol. Again, as described previously, this is a two-handed operation, if proper training regimens are followed.
[0006] At the end of the officer's duty shift, the service weapon must be unloaded, cleared and visually checked to ensure it is unloaded and then secured appropriately. This is a reversal of the loading process described above where the magazine is removed, the slide cycled to eject any round that might be in the chamber or breach, the slide locked in the open position, an inspection of the chamber/breach conducted to “prove” the weapon unloaded and safe and then the proper securing of the weapon in the holster or carrying case, as dictated by policy/local laws.
[0007] However, what does the officer do if their primary or secondary hand is injured, damaged, incapacitated or otherwise occupied in some way to make it impossible to use in the loading, firing, reloading and unloading of their weapon?
[0008] Injuries to the primary, or secondary hand of an officer can occur in many different ways including, but not limited to, a struggle with a suspect, a knife wound, a gunshot wound, having the hand stepped on, impacted with a weapon including sticks, rocks, bricks or fixed objects or slammed in between objects such as car doors or structure doors and their frames, among others. The officer's secondary hand can, in addition to be injured, be otherwise occupied during the performance of their duties while holding another object, including but not limited to, a flashlight, a baton, a pepper spray can, a riot shield or the handling of a service dog. They could also be holding down one suspect while another is still considered a threat or could also be shielding a member of the public while still encountering a continued threat from a suspect.
[0009] In these cases, current training regimens teach the officer to manipulate their weapon for loading using one hand only. Some police departments train for this situation, others do not. In cases where training is provided, the officer is shown techniques to cycle their weapon using techniques that are less than effective and involve fine motor skills, require improvisation and often deviate from police tactical principles, e.g. generally requiring the officer to become static. As many of these techniques involve less than ideal practices and are time consuming, e.g. many require the officer to seek cover first thereby completely removing them from the fight, no one tactic or system has become widely accepted in contrast to the two-handed manipulations drills.
[0010] Accordingly, when the situation arises where an officer must clear a weapon malfunction as described above when using only one hand, a whole new set of problems arise. There are essentially two main techniques taught for clearing malfunctions with one hand in North America. The first for “live trigger” stoppages requires the officer to find a surface of opportunity to ensure the magazine is seated properly then find a surface suitable to balance the front of the weapon (often the sight—leading to other issues) in order to cycle the action rearward. In the second, for “dead trigger” or double feed stoppages as described above, an officer must find a surface suitable to balance the front of the weapon (often the sight—leading to other issues) in order to cycle the action rearward and lock it in place. With the action open and pressure somewhat eased on the rounds in the chamber/breach, the officer must find a hard and sharp surface to strip the magazine from the pistol. This requires focus and thought as this is often a surface of opportunity. With the magazine stripped the officer must ensure the breach, chamber and magazine well are clear. The officer must then find a place to semi-secure the pistol in an improvised position of opportunity, typically behind a leg or partially in a holster as the action is still open. With the pistol semi-secure the officer must then retrieve and try to seat a magazine in the pistol. Only then, with a seated magazine can the officer grasp the pistol and send the slide forward to cycle a round into the chamber. Should the action/slide have cycled forward by accident during the manipulation prior to the seating of the magazine, the officer would be required to find a surface suitable to balance the front of the weapon in order to cycle the action rearward. Placing such pressure on the front sight can affect the alignment of the sights and greatly affect the ability of the pistol to be aimed properly. Pressure on the sight can also damage the front sights or post to a degree where the weapon cannot be aimed at all.
[0011] These prior art options involving one handed manipulations are time consuming and can take even a well-trained officer 35-45 seconds under range situations. This does not include the time it could take the officer to seek cover in order to complete these “static” tasks nor their trying to complete these actions whilst protecting an individual, holding a struggling individual, trying to stay under cover, etc. Under these circumstances and others where an officer was trying to complete the above clearing procedures one handed in a situation where they were under fire, involved in a hand to hand confrontation or injured, with stress levels at the highest possible levels, such a procedure could very well take considerably longer. Further, depending on variables such as surfaces in the immediate area, and no standard procedure, there is also limited guarantee of success.
[0012] Accordingly, the inventors have established a solution to address the problems associated with one handed manipulation of a service pistol. The “Taelin Tactical System” established by the inventors is based upon two components and their related inserts that form a complete “system” allowing for single handed loading, cycling, firing, clearing and unloading of hand held semi-automatic pistols. The system is adaptable to various types of semi-automatic pistols and other firearms.
[0013] Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.
SUMMARY OF THE INVENTION
[0014] It is an object of the present invention to provide a solution to address problems associated with one-handed manipulation of a service pistol.
[0015] In accordance with an embodiment of the invention there is provided a device comprising: a spine; a cover pivotally attached to the spine and operable under action of a user from a first normally closed position and a second open position; a spring connected to the cover and spine holding the cover without a first action of a user in the first normally closed position; a base dimensioned to support a firearm magazine such that the firearm magazine is axially aligned to an axis of the spine; and a pair of retaining arms attached to the spine for retaining the firearm magazine within the device without a second action of the user and releasing the firearm magazine under the second action of the user.
[0016] In accordance with an embodiment of the invention there is provided a device comprising: a spine; and a retainer attached to the spine wherein the retainer comprises at least a first groove tapering from a first width towards the pivotal attachment between the cover and spine to a second width towards the front edge of the cover.
[0017] Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures, wherein:
[0019] FIG. 1 depicts the different elements of a semi-automatic firearm;
[0020] FIG. 2 depicts the two-handed procedure for loading a new magazine for a semi-automatic firearm;
[0021] FIG. 3 depicts an exploded assembly for a magazine/clip retainer (MAGRET) according to an embodiment of the invention;
[0022] FIG. 4 depicts a MAGRET according to an embodiment of the invention in a closed position without magazine/clip inserted;
[0023] FIG. 5 depicts a MAGRET according to an embodiment of the invention in an open position without magazine/clip inserted;
[0024] FIG. 6 depicts a MAGRET according to an embodiment of the invention in unassembled and assembled views in open position with magazine/clip;
[0025] FIG. 7 depicts a MAGRET according to an embodiment of the invention in unassembled and assembled views in closed position with magazine/clip;
[0026] FIG. 8 depicts a slide CYCLER (CYCLER) according to an embodiment of the invention;
[0027] FIG. 9 depicts a user using a MAGRET according to an embodiment of the invention with one-hand;
[0028] FIG. 10 depicts a dual MAGRET with integral receiver according to an embodiment of the invention; and
[0029] FIG. 11 depicts a MAGRET with sprung loaded base according to an embodiment of the invention.
DETAILED DESCRIPTION
[0030] The present invention is directed to firearms and more particularly towards a magazine holder and a cycling holder, each allowing for quick and efficient cycling of a semi-automatic firearm with one hand.
[0031] The ensuing description provides exemplary embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the disclosure. Rather, the ensuing description of the exemplary embodiment(s) will provide those skilled in the art with an enabling description for implementing an exemplary embodiment. It being understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope as set forth in the appended claims.
[0032] As described below in respect of FIGS. 2 through 9 the “Taelin Tactical System” (hereinafter TTS) established by the inventors is based upon two components and their related inserts that form a complete “system” allowing for single handed loading, cycling, firing, clearing and unloading of hand held semi-automatic pistols. The TTS is adaptable to various types of semi-automatic pistols and other firearms and comprises a MAGRET 300 (MAGRET) and the Slide CYCLER (CYCLER). These, may within an embodiment of the invention, be designed so that they can be worn on a regulation police style or military duty holster, a plain clothes 1½″ wide dress belt or attached to a Modular, Lightweight, Loadbearing, Equipment (MOLLE) tactical system vest. These systems can also be mounted to police tactical ballistic or riot shields, armoured cars or any surface where a firearm could be in use nearby.
[0033] The MAGRET 300 (MAGRET) permits one handed access to a fully loaded magazine of ammunition held in an upright position, facing forward, where the officer uses the butt of their service weapon to flip up the spring (or lever/friction) loaded protective cover/lid, places the handle of the weapon directly over the loaded magazine (where it naturally will want to fall), slides the weapon down over top of the magazine, tilts or rotates the magazine out of the holder while continuing the downward motion thus loading the pistol. The user then taps/seats the magazine on the top of the spring loaded protective clip cover/lid, to give the officer a fully loaded weapon in just a few seconds.
[0034] The CYCLER then allows the officer to place the muzzle of the weapon in the gross opening groove of the CYCLER and push downward. The groove narrows, catching the slide safely allowing the pistol to load a round of ammunition into the chamber of the weapon to easily provide the officer with a ready-to-fire weapon. This motion is completed quickly, smoothly and in an ergonomically economical, flowing manner. This system is based on tactile feedback (feel) and a user (who is familiar with a semi-automatic pistol) can become proficient with very little practice. The TTS is designed to provide tactile feedback (the feel) consistent with two handed operation thus promoting a familiarity when using the system.
[0035] Referring to FIG. 1 , there are depicted in first and second views 100 A and 100 B the different elements of a semi-automatic firearm. As depicted in second view 100 B a firearm generally comprises in assembled state a firearm body 170 and a magazine/clip 160 . The firearm body 170 as depicted in first view 100 A comprises a front sight 105 , a slide 110 which must be cycled to load the first bullet (shell) or clear a live round jam by moving it relative to case 165 and hand grip 155 , an ejection port 115 through which spent bullets (shells) are ejected, a rear sight 120 , and a hammer 125 . There is also a safety 130 , which may be for left handed user, right handed user, or a pair for one-for-all-users. Additionally, there are slide release 140 , trigger guard 145 , trigger 175 , and magazine release 150 which releases the loaded magazine/clip allowing it to be replaced with a full or partially loaded magazine or stored without a magazine/clip.
[0036] FIG. 2 depicts the two-handed procedure for loading a new magazine for a semi-automatic firearm. These are depicted as:
[0037] Step 200 A—Identify the Need: An emergency reload or standard reload is needed when you have spent all the rounds from your magazine 160 and your slide 110 is locked back
[0038] Step 200 B—Get Fresh Magazine: Grab a fresh magazine 160 (likely from a magazine pouch) after the slide has locked back on an empty magazine 160 , and move the fresh magazine 160 toward the gun.
[0039] Step 200 C—Eject the Empty Magazine 160 : Be sure not to lose your old magazine 160 , and bring your new magazine 160 into place below the magazine 160 opening. With well-trained users these should essentially pass each other during the reloading close to the bottom of the firearm. Ejecting the magazine 160 requires the user push the magazine release 150 and having the bottom of the hand grip 155 clear to allow the magazine 160 to come out.
[0040] Step 200 D—Insert the Magazine 160 : Place the rear of the magazine 160 against the rear of the magazine 160 well of the firearm body 170 , align the two, and with some force (though there should be little resistance) insert.
[0041] Step 200 E—Seat the Magazine 160 : Using the heel of their palm the user must give the magazine 160 a tap such that the magazine 160 clicks into place within the firearm body 170 .
[0042] Step 200 F—Cycle the Slide 110 : Placing one hand over the top of the slide 110 and holding the firearm grip 155 pull the slide 110 back towards their chest. Care must be exercised at this point to ensure that the user's finger(s) are not caught in the slide opening, or that anything else such as clothing might get caught.
[0043] Step 200 G—Release: Now the slide is released, so it can go forward with full force. This will seat the next round in the chamber, preparing it for discharge.
[0044] FIG. 3 depicts an exploded assembly for a magazine/clip retainer (MAGRET) 300 according to an embodiment of the invention. The MAGRET 300 is assembled upon a spine 310 , which may for example be made from impact resistant Delrin™, polyoxymethylene, although other impact resistant polymers, fiber reinforced polymers, etc. may be employed as well as lightweight composites and metals, e.g. aluminum. Beneficially, in some circumstances selection of Delrin™ or another plastic material also permits the use of the system in cold weather climates where metals would stick to exposed flesh as well as potentially scratch and damage parts of the weapon during use.
[0045] The spine 310 is designed to permit attachment to a standard police or military style duty belt measuring approximately 2¼″ high and ¼″ thick through a slot 310 A, for example, or alternatively by deploying an alternative spine, insert, attachment and/or conversion for use on a plain clothes dress belt, such as the BlackHawk CQC carbon fibre belt model 4113PBK for example measuring approximately 1½″ high and ¼″ thick, or for attachment on a MOLLE style tactical vest such as currently in use by law enforcement and military around the world. It would be evident that through variations of an insert 325 which may be retained within the spine 310 through screw fittings (not shown for clarity) that the spine 310 may be fitted to a wide variety of belts, straps etc. Alternatively, the slot 310 A discretely and/or in combination with other mounting fixtures not shown for clarity may allow for the spine 310 to be mounted through a variety of mounting fixtures such that the MAGRET 300 may be easily adapted to mount onto not only a wide range of vests, protective wear, equipment etc. but also that the MAGRET 300 may also be attached to a variety of surface mounting systems, e.g. the inside of a police shield or an interior surface of an urban protection vehicle.
[0046] The spine 310 and insert 325 may themselves be secured to the duty belt, for example by using two 8-32 socket head set screws for the Police 2¼″ duty belt for example, or one 8-32 socket head set screw for the plain clothes duty belt rather than relying upon a friction fit or interference fit so that the spine stays in position and does not shift when the officer comes to apply pressure/force to it. The spine 310 and other components of the MAGRET 300 may be coloured black, for example, to blend in with current material colouring of tactical and police duty equipment as well as providing long service life and durability. However, the colour can be adapted to match operational environment included, but not limited to, pixelated patterns etc. as commonly found in military camouflage. As the TTS is based upon tactile feedback (feel) such that the user can quickly landmark and use the system this makes finding the unit based on color flexible according to the environment.
[0047] The spine 310 has two flexible arms, first and second arms 315 and 320 respectively, attached to the right and left sides respectively as viewed from the front which orient and lock the ammunition clip (magazine 160 ) in position within the MAGRET 300 , leaving it standing upright, straight and facing forward. The first and second arms 315 and 320 respectively are designed to flex outward whenever a magazine 160 is rotated into or out of the retainer and flex back into normal position when the magazine 160 is in place thereby holding it correctly oriented and secure. The top surfaces of each MAGRET 300 arm are rounded downward toward the outer edges so that a downward motion for loading the magazine 160 can still occur as the magazine 160 undergoes simultaneous rotational motion during its removal from the MAGRET 300 . Accordingly, the user in loading a new magazine can place the well within the firearm handle 155 over the top of the magazine 160 such that subsequently as they begin pushing downwards they pivot the firearm from their body so that the magazine is removed from the first and second arms 315 and 320 respectively and continues insertion into the firearm.
[0048] The first and second arms 315 and 320 respectively of the MAGRET 300 may each be secured to the spine 310 with two 6-23 flat head machine screws on each side to permit the arms to be replaced quickly and easily should they become damaged through use or abuse. These are depicted as first screw pair 350 A/ 350 B and second screw pair 350 C/ 350 D respectively. The first and second arms 315 and 320 respectively are also replaceable to permit exchanging of these MAGRET 300 arms for retaining arms suited to a different width of magazine 160 , for example. Accordingly, the first and second arms 315 and 320 respectively can be quickly and easily changed such that a common spine is employed. Similarly, an array of spines 310 may be disposed as a single unit, an array of multiple units, or an array of discrete units wherein different spines 310 are provided with different first and second arms 315 and 320 respectively (and possibly base 330 ) allowing multiple magazines 160 to be stored and rapidly accessed, e.g. upon the inner surface of a lid of a police cruiser trunk, allowing multiple firearms to be accommodated. In such instances, a colour coding or text identifier may be applied to the first and second arms 315 and 320 respectively or the outer exposed surface of the cover 305 .
[0049] Between the first and second arms 315 and 320 respectively of the MAGRET 300 and attaching to the spine 310 is an adjustable spacer 345 , or standoff, which can be quickly changed to accommodate different thicknesses of magazines 160 from various firearms manufacturers much like the first and second arms 315 and 320 respectively provide for accommodation of different magazine 160 widths. To fit and adjust the MAGRET 300 to a different size magazine 160 , a 6-32 socket head set screw 350 E used to attach the spacer 345 to the spine 310 is loosened on the spacer 345 . The spacer 345 forms a second part of an assembly of two pieces, the other being element 310 C forming part of the spine 310 which are each stepped in increments of approximately 0.031″. The spacer 345 can be adjusted upwards or downwards before being screwed into position via screw 350 E. The spacer 345 may be visually slid until the surface of the spacer 345 just touches the inner surface of the magazine 160 when held in position inside the MAGRET 300 . Once the socket head screw is re-tightened, the spacer 345 is locked into position and properly supports the inside edge of the magazine 160 from movement.
[0050] This spacer 345 also performs the function of a standoff to ensure that the inside edge of the magazine 160 is far enough away from the spine 310 and protective cover 305 so as not to catch the officers' fingers on the spine 310 or cover 305 when performing the loading function. Alternative means of providing adjustably positioned spacer 345 may be envisioned in other embodiments of the invention whilst in other embodiments the spacer 345 may be integrally formed with the spine 310 such that the MAGRET 300 is dimensioned and not adjustable. Such a design may be employed for example where a single firearm is deployed for police officers within a police force and only a single magazine 160 design is employed. In a similar manner, as different first and second arms 315 and 320 respectively may be employed colour coded and/or labelled for particular firearms 170 /magazines 160 then the same may be applied to spacer 345 . Optionally, spacer 345 may be varied in thickness and fixed in the same position rather than being slidable.
[0051] The top of the magazine 160 and the ammunition rounds within it are protected when held inside the MAGRET 300 by a spring loaded protective magazine cover 305 , or lid, which is attached to the spine 310 and held in place with a ⅛″ diameter hinge pin approximately 1¾″ long whilst spring loading is provided via spring 335 . Fitting over the hinge pin and within the inner diameter of spring 335 is hinge pin cover 340 . The underside of this protective cover/lid may have a machined relief 305 A in it that has been filled with a soft, open cell foam which protects the top of the clip and rounds of ammunition from damage. Alternatively, a soft material, such as rubber, foam, etc. may be applied to the underside of the cover 305 . On the underside of the protective magazine cover 305 , running from left to right on the front edge of the cover 305 , is a slot 305 B machined into the surface to permit positive catching of the protective cover/lid by the bottom edge of the hand grip 155 when the firearm is used to flip the cover 305 open to access the magazine 160 within the MAGRET 300 for loading. The protective cover 305 also acts as a deflector to stop the top of the magazine from catching on clothing or equipment or being grabbed and pulled out of the MAGRET 300 during a struggle by the officer. Further, protective cover 305 may provide a resilient flat surface for the officer to push the bottom of the magazine 160 against to ensure that it is seated and secured within the hand grip 155 .
[0052] The base 330 of the MAGRET 300 has been designed to be changeable from one firearm magazine 160 to another by removing one 6-32 socket head cap screw, then sliding the base 330 upward to disengage from tongue 310 D of spine 310 . Alternative fixing and/or mounting means may be employed without departing from the scope of the invention. The base 330 used on any particular magazine is determined by the firearm manufacturer of the firearm the officer will be using. Each manufacturer's weapon magazine is slightly different from another even though they follow similar design and manufacturing principles. For example, the size of the magazine base may vary, the angle of the magazine base relative to the magazine body may vary, and the overall length may also vary. As a result, the base 330 for any given spine 310 may be specifically designed to accommodate and fit a particular weapon. For example, a base 330 may be designed specifically for a Smith & Wesson (S&W) 500. Each base 330 is designed and may be manufactured in both a right hand (RH) and left hand (LH) version to suit both right and left handed shooters so that independent of hand configuration installed, the nose of the ammunition rounds loaded into a magazine 160 face forward when mounted on the officers duty belt, to allow for correct loading of the weapon.
[0053] In order for the MAGRET 300 base 330 to handle the stresses and forces exerted on it during the loading process, a compound dovetail design is depicted within FIG. 3 which causes the base 330 to press into and hold tighter to the groove 310 D of the spine 310 as more force is exerted on it. The socket head cap screw retains the base 330 in place and stops it from falling off the spine 310 . In the case of the S&W model 5946 the base 330 also incorporates an angle of approximately 18° towards the rear of the base 330 which makes use of gravity to push the clip downward and backward in the base 330 thereby holding it securely in position and spreading out any forces exerted on the base 330 , through the magazine 160 , during the loading process. This 18° angle represents the angle of the firearm handle 155 relative to the perpendicular of the slide for an S&W model 5846 firearm. This angular dimension for the MAGRET 300 may differ for each model of firearm it is adapted to.
[0054] The MAGRET 300 base 330 is also designed to have a tolerance around the actual base 330 of the clip itself in a pocket 330 A to permit the clip to be placed into the base 330 and then rotated into position and locked in by the first and second retainer arms 315 and 320 respectively without catching on the base 330 pocket edges. Each MAGRET 300 base 330 may be engraved/cast on the underside with the angular information for the base 330 , manufacturers name and weapon model number as well as the hand of orientation (i.e.: right hand RH and left hand LH).
[0055] Referring to FIG. 4 there are depicted first to third views 400 A to 400 C respectively for a MAGRET according to an embodiment of the invention in a closed position without magazine 160 inserted. Such a MAGRET being, for example, MAGRET 300 such as described supra in respect of FIG. 3 .
[0056] Referring to FIG. 5 there are depicted first to third views 500 A to 500 C respectively for a MAGRET according to an embodiment of the invention in an open position without magazine 160 inserted. Such a MAGRET being, for example, MAGRET 300 such as described supra in respect of FIG. 3 .
[0057] Referring to FIG. 6 there are depicted first to third views 600 A to 600 C respectively for a MAGRET according to an embodiment of the invention in an open position with magazine 160 . Such a MAGRET being, for example, MAGRET 300 such as described supra in respect of FIG. 3 . In first view 600 A the magazine 160 is shown unassembled from MAGRET 300 whereas in second view 600 B the magazine 160 is depicted tilted such as it would be during insertion into a firearm as the officer pushes the firearm down and pivots it away from the MAGRET 300 spine 310 and base 330 . In third view 600 C the magazine 160 is depicted mounted such as it would be during normal storage within the MAGRET 300 wherein it is seated within the base 330 and the magazine 160 is parallel to the spine 310 .
[0058] Referring to FIG. 7 there are depicted first to third views 700 A to 700 C respectively for a MAGRET according to an embodiment of the invention in a closed position with magazine 160 . Such a MAGRET being, for example, MAGRET 300 such as described supra in respect of FIG. 3 . In first and second views 700 A and 700 B respectively the magazine 160 is shown assembled within the MAGRET 300 from rear and side perspectives. In third view 700 C the magazine 160 is depicted mounted within the MAGRET 300 from the front with the lid 305 closed and the magazine 160 seated within the RH base 730 RH. Also depicted discretely is LH base 730 LH.
[0059] Now referring to FIG. 8 there are depicted first and second views 800 A and 800 B of a CYCLER according to an embodiment of the invention. The CYCLER comprises two components within this embodiment, the CYCLER spine 820 and receiver 810 . As with the spine 310 of the MAGRET the CYCLER spine 820 may be made of impact resistant Delrin™, for example, and be designed to permit attachment to a standard police or military style duty belt measuring approximately 2¼″ high and ¼″ thick or, by deploying an insert, similar to insert 325 of the MAGRET 300 which fits within slot 825 , attachment and conversion for use on a plain clothes dress belt such as the BlackHawk CQC carbon fibre belt model 4113PBK measuring approximately 1½″ high and ¼″ thick or attachment on a MOLLE style tactical vest currently in use by law enforcement and military around the world. Within other embodiments of the invention the CYCLER may be mounted through other fittings that fit the slot 825 in order that the CYCLER may be mount onto not only a wide range of vests, protective wear, equipment etc. but also that the CYCLER may also be attached to a variety of surface mounting systems, e.g. the inside of a police shield or an interior surface of an urban protection vehicle.
[0060] The CYCLER spine 820 may be secured to the duty belt by two 8-32 socket head set screws for the Police or Military 2¼″ duty belt for example or one 8-32 socket head set screw for the plain clothes duty belt with an insert within the slot 825 within the CYCLER spine 820 . In this latter instance the other 8-32 screw secures the insert into the slot 825 within the CYCLER spine 820 . As with the MAGRET 300 the selection of Delrin™ as the material also permits the use of the system in cold weather climates where metals would stick to exposed flesh as well as potentially scratch and damage parts of the weapon during use. Similarly, a black colour for the Delrin™ may be chosen to blend in with current material colouring of tactical and police duty equipment as well as providing long service life and durability. Color can be adapted to match operational environment such as described supra in respect of MAGRET 300 which may also include pixelated patterns. The TTS concept exploiting the CYCLER is based upon tactile feedback (feel) such that the user can quickly landmark and use the system. This makes finding the unit based on color flexible such that the receiver 810 may be colour coded according to the firearm or firearms it is intended to work with.
[0061] Within an embodiment of the invention the CYCLER spine 820 is machined such that there are three positions for mounting the receiver 810 which attaches to it. The main position is vertical down (VD) but the CYCLER spine 820 can also align the receiver 810 30° to the left or right to permit mounting for both right and left handed shooters. This provides exceptional adaptability to placement on the belt or vest/arm or leg harnesses including those with MOLLE systems. It would be evident that other designs may provide more or less predetermined orientations as well as continuously variable designs.
[0062] In order for the CYCLER spine 820 and receiver 810 to handle the stresses and forces exerted during their use a similar round dovetail slot design may be used as with the MAGRET 300 such that pressure applied to the CYCLER spine 820 causes it to press into and hold tighter within the receiver 810 . Mounting of the CYCLER spine 820 and receiver 810 in FIG. 8 is achieved through a single 6-32 flat head machine screw to hold the receiver 810 in place and stop it from falling off the CYCLER spine 820 during use or changing angle orientation. Accordingly, the receiver 810 is provided with a single, round, dovetail protrusion on the back surface that fits into one of the three dovetail orientation slots for VD, 30° RH or 30° LH machined into the CYCLER spine 820 .
[0063] The exposed accessible surface of the receiver 810 is, according to an embodiment of the invention, a slot 815 approximately 0.350″ wide and 0.190″ deep running along the CYCLER vertical centerline from the top edge of the receiver 810 downwards for approximately 2.544″ in which the front sights of the weapon are guided and protected from impact that might cause misalignment or damage during the cycling process of the weapons slide. The left and right walls of the receiver 810 create a tapered region 825 which is wide at the top edge of the receiver 810 and tapers inward to create the required tapering profile as the walls progress down the receiver 810 . These tapered walls grip the sides of the weapon as force is applied downward thereby stopping the downward motion of the slide but allowing the frame and barrel of the weapon to continue downward motion that will result in a round of ammunition being loaded into the weapons chamber or breach. This loading or cycling action brings the officers weapon to ready-to-fire status in a matter of seconds with just the use of one hand. The slot 815 and tapered region 825 within receiver 810 are depicted within the cross-sections A-A and B-B.
[0064] The receiver 810 depicted with a wide tapered slot permits the receiver 810 to be utilized with a large selection of firearms currently manufactured and on the market without having to change parts or customize the receiver 810 to a specific weapon or manufacturer. The tapering of the slot also permits for a gross motor action in finding and using the CYCLER with the semi-automatic firearm. The user must only index one side or part of the opening then follow the motion through as the taper will guide the slide to proper orientation and then grip it, allowing the pistol to be cycled. In some instances, due to particular characteristics of the firearm sights, barrel, slide etc. the receiver 810 may be customized to the firearm or perhaps the user due to a peculiarity of their action.
[0065] According to an embodiment of the invention, a user has a CYCLER 800 A, 800 B, a holster, and a MAGRET 300 upon their belt, and has within their right hand a firearm 170 from which they have just released a magazine 160 . The user moves the firearm 170 back to the CYCLER and pushes the slide down into the CYCLER such that it is retained and the user's continued action on the firearm 170 cycles the action. The user brings the firearm 170 forward, which is now cycled with the slide pushed back, and the ejection port is open allowing the user to visually check that the firearm 170 is cleared.
[0066] FIG. 9 depicts a user using a MAGRET according to an embodiment of the invention with one-hand in first to fourth images 1000 A to 1000 D respectively. In first image 1000 A the user brings their firearm 170 to the MAGRET 300 , then in second image 1000 B they engage the cover with the bottom edge of the firearm handle lifting it before pushing the well in the firearm handle down over the magazine. As depicted in third image 1000 C as they continue pushing down they pivot the firearm away from their bodies removing it from the retaining arms of the MAGRET 300 until the magazine is inserted into the firearm. Next in fourth image 1000 D the user brings the firearm with the newly installed magazine back to the top of the MAGRET 300 allowing them to push the firearm down against the cover of the MAGRET 300 to ensure the magazine is fully seated.
[0067] Now referring to FIG. 10 , there is depicted a dual MAGRET assembly with integral receiver according to an embodiment of the invention. As depicted in first and second views 1100 A and 1100 B respectively there are a pair of MAGRET, first and second MAGRET 1110 A and 1110 B, that share a common cover 1110 D atop of which is a receiver 1110 C such as described supra in respect of receiver 810 in FIG. 8 . Accordingly, the user of the dual MAGRET assembly has available two spare magazines when loaded into the dual MAGRET assembly whilst still being able to use the receiver 1110 C to cycle the slide of the firearm and the other portion of the cover 1110 D to ensure a newly loaded magazine is seated into the handle of the firearm.
[0068] Now referring to FIG. 11 there is depicted a MAGRET with sprung loaded based according to an embodiment of the invention. As depicted in first view 1200 A a MAGRET spine 310 has attached a base 1210 which is depicted in “closed” position as if the magazine were loaded but the magazine has been omitted for clarity. Subsequently, in use a user is loading the magazine into a firearm with the motion defined above wherein the user in pushing the firearm down over magazine has also started an arcuate motion pivoting the top of the firearm away from their body. Accordingly, in the embodiment of the invention described supra in respect of FIGS. 3 through 7 this action pivots the magazine off the base 330 of MAGRET 300 . In contrast as depicted within FIG. 11 the base 1210 comprises upper and lower sections 1210 A and 1210 B respectively which are coupled via a pivot 1210 D at one end and have a spring 1210 C mounted between them at the other end towards the spine 310 . Accordingly, as the user pivots the magazine then the upper section 1210 A pivots away with it. Optionally, the spring 1210 C may be replaced with another element providing pressure to maintain the upper section 1210 A in contact with the magazine or removed wherein contact between the upper section 1210 A and magazine is maintained through the pressure applied to the firearm and magazine by the user in performing the action.
[0069] Whilst embodiments of the invention in respect of the MAGRET have been described from the viewpoint of an assembly in respect of FIGS. 3 through 11 it would be evident to one skilled in the art that multiple elements of the assembly may be machined and/or molded as a single piece-part to which other elements may be assembled. Accordingly, it would be evident that the spine and base may be formed together or that the spine, base and retainer arms may be formed together such that design aspects of the retainer arms provide the required degree of flexibility even if formed from a material otherwise considered to be resilient.
[0070] The foregoing disclosure of the exemplary embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many variations and modifications of the embodiments described herein will be apparent to one of ordinary skill in the art in light of the above disclosure. The scope of the invention is to be defined only by the claims appended hereto, and by their equivalents.
[0071] Further, in describing representative embodiments of the present invention, the specification may have presented the method and/or process of the present invention as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. In addition, the claims directed to the method and/or process of the present invention should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the present invention.
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A system facilitates one handed manipulation of a service pistol and includes a device having two components and related inserts that allow for single handed loading, cycling, firing, clearing and unloading of semi-automatic pistols. The present device includes a spine, a cover pivotally attached to the spine and operable under action of a user from a first normally closed position and a second open position, a spring connected to the cover and spine holding the cover without a first action of a user in the first normally closed position. A base is dimensioned to support a firearm magazine such that the firearm magazine is axially aligned to an axis of the spine; and a pair of retaining arms are attached to the spine for retaining the firearm magazine within the device without a second action of the user and releasing the firearm magazine under the second action of the user.
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CROSS-REFERENCE TO RELATED PATENTS AND APPLICATIONS
[0001] This non-provisional application is based upon and claims domestic priority benefits under 35 USC §119(e) from copending U.S. provisional patent application Ser. No. 61/709,856, filed on Oct. 4, 2012, the entire contents of which are hereby expressly incorporated herein by reference. The provisional patent application Ser. No. 61/709,856 and this non-provisional application based thereon are commonly owned by Axxia Pharmaceuticals LLC (“Axxia”).
[0002] Axxia also owns prior issued U.S. Pat. Nos. 5,633,000; 5,858,388; and 6,126,956 and pending U.S. Ser. Nos. 12/738,113; 61/533,131; 13/264,813; 13/606,795; and 2008/011908, the entire contents of each such prior-issue US patent and pending patent application commonly owned by Axxia being expressly incorporated herein by reference. These Axxia prior patents and applications relate to controlled release medical implant products and various non-3-D printing processes for making those products. According to these Axxia prior patents and applications, the implants (i) may be non-biodegradable or biodegradable; (ii) may provide drug delivery over a few days, weeks or months; (iii) may provide a steady drug release without a “burst”; and (iv) may be in various sizes to accommodate the desired drug delivery schedules. Significantly, none of these prior Axxia patents or patent applications teach or suggest a 3-D printing method, let alone the 3-D printing method of this invention.
FIELD
[0003] This application sets forth novel 3-D printing processes for making subcutaneous medical implant products that provide for the controlled release of non-narcotic as well as opiate, opioid and/or other narcotic drugs over a period of days, weeks or months. These novel processes can be used to make a wide variety of subcutaneous medical implant products having self-contained controlled release drugs beyond those specifically disclosed in Axxia's prior patents and applications. The present invention covers both the 3-D printing processes described below and the products made by those processes.
[0004] Although the present invention is primarily described herein with respect to medical implant products, the invention also is applicable with respect to medical non-implant products, such as tablets having time release capabilities and/or containing opioid products. Thus, for example, the detailed description of the processes and products set forth herein with respect to implants are readily adaptable to non-implant products as would be readily understood by one of ordinary skill in the art after reading this disclosure.
[0005] Further, the drug and non-drug materials in the present invention are not limited to the materials disclosed in the Axxia patents and applications—e.g., there is no limitation to the hydromorphone drug or to the EVA, TPU or silicone coating/matrix materials. For example, the drug materials may be narcotics and/or non-narcotics. Likewise, the non-drug materials may be biodegradable or non-biodegradable.
[0006] Thus, in addition to hydromorphone, this process also can be used to make the probuphine implants of Titan Pharmaceuticals, the implants of Purdue Pharma and the implants products of other companies. See, e.g., U.S. Pat. Nos. 8,114,383 and 8,309,060. In other words, this application covers all subcutaneous medical implant products containing controlled release drugs that are capable of being made by the invention.
[0007] The present processes and the products made by those processes are useful in at least four fields of use: (1) the narcotic abuse field; (2) the drug compliance field (both narcotic and non-narcotic drugs); (3) the pain management field; and (4) the animal heath field.
BACKGROUND
[0008] Inkjet and other printing processes have been used in many fields to manufacture products. For example, inkjet printing processes have been used in the manufacture of LCD and semiconductor products. See, e.g., Re. 37,682, which although it involves an unrelated technical field is incorporated by reference herein in its entirety.
[0009] In addition, printing processes (such as screen printing and low temperature casting techniques) have been the subject of consideration for the manufacture of other medical (non-implant medical devices or non-self-containing drug implants) products. See, e.g., “Printing Evolves: An Inkjet For Living Tissue,” published in the Wall Street Journal on Sep. 18, 2012 at pages D1 and D3; and the Axxia patents/applications.
[0010] Further, non-printing methods have been used to create medical implant products, via conventional methods. These non-printing methods include, inter alia, hot-melt casting, extrusion, shrink-wrap and solvent based processes.
[0011] While some prior art processes have commercial advantages and they can be used as a part of the invention herein, it is the inventors' opinion that these prior art processes alone (i.e., when used without at least one 3-D printing process step) fail to satisfy at least one or more of the advantages that the present 3-D printing invention seeks to provide for controlled release subcutaneous medical implant devices and medical non-implant products. For example, a partial listing of the advantages that may result from the present 3-D printing invention are believed to include at least some of the following:
1. The structure of the non-drug portions of the implant or non-implant product may be designed and controlled rather precisely due to (i) the small, precise amounts of material deposited by each 3-D nozzle and (ii) the very thin or ultra-thin layer-by-layer building method of 3-D printing; and 2. The drug release pattern of the implants or non-implants may be precisely regulated by the use of the 3-D nozzles to create the product on a layer-by-layer basis for the same reasons; and 3. The shape and configuration of the implant or non-implant may be modified as desired by, for example, using the 3-D printing nozzles to deposit non-permanent materials that may be readily removed by etching, laser, mechanical, chemical or other known means; and 4. The present invention may avoid irregularities resulting from cutting or otherwise modifying extruded materials; and 5. The present invention may sometimes avoid the separate step of loading a drug material within the implant or non-implant because, for example, the precise ratio of the drug material and the non-drug material in the matrix core can be precisely regulated and the release path and release rate of the drug materials within the matrix core to the opening in the implant or non-implant device can be precisely designed; and 6. The present invention may provide great flexibility in the choice and use of both drug materials and non-drug materials, whereas, for example, certain previously known processes limit the commercial choice of plastic/thermoplastic/drug materials; and 7. Large numbers of implants or non-implants may be created at one time and/or quickly so that, e.g., the overall yield is increased; and 8. The present invention may provide improved bonding/adhesion between the drug containing matrix and other portions of the implant or non-implant (e.g. the coating); and 9. High manufacturing yield may be achieved—e.g., approaching as high as about 90-95%. Thus, for example, with hydromorphone costs of approximately $12,000/kg, this may be an important competitive advantage, especially in developing world markets.
However, it should be understood that the present invention does not require that all of these advantages be achieved in every process or product covered by the scope and spirit of the invention.
SUMMARY
[0021] In general, the present invention relates to computer-controlled 3-D printing methods that are used (either wholly or in part) to manufacture controlled release medical implant or non-implant products. One type of 3-D printing is sometimes referred to as fused deposition modeling (FDM). This invention is not limited to any one type of 3-D printing. Further, and indicated previously, this invention covers both implant and non-implant processes and products. For the purpose of providing a detailed description of the invention, that description will focus upon implant processes and products. However, those processes also are applicable to the manufacture of non-implant products as would be readily understood by one of ordinary skill in the art after reviewing that description.
[0022] These subcutaneous implants provide for the controlled release of self-contained drugs (whether they are narcotic or non-narcotic drugs) over at least a several week period. In one embodiment of the invention, the controlled release time period is 30 days or longer. However, the controlled release period may, in fact, also be a shorter period of time, such as 3, 7, 14 or 21 days. Although a steady controlled release is frequently desired, the release rate can be varied over time. In addition, more than one drug may be released by an implant made in accordance with the invention.
[0023] The 3-D printing method may be accomplished via an array of 3-D nozzles that deposit materials (such as plastics, thermoplastics, coating materials, drug-containing matrix materials, non-drug containing matrix materials, bonding materials, biodegradable materials and/or the like) in very small, precise portions. The materials may be deposited in liquid, powder, sheet or other forms.
[0024] For example, the array of nozzles may be used to deposit one or more of these materials on a thin or ultra-thin layer-by-layer basis to create/build the final controlled release medical implant product. Although the 3-D nozzles may deposit the materials in droplet form, the use of the nozzle array typically will result in a non-droplet shape at each layer/slice. In one embodiment, there is a separate array of 3-D nozzles for at least one portion of each layer.
[0025] However, the number of separate arrays of 3-D nozzles may be minimized so long as the 3-D nozzles are capable of depositing more than one type of material at different times during the process. Because this presently may be commercially impractical with respect to some materials, it may not always be a preferred process feature. Nevertheless, the scope of the invention cannot be avoided by this modification.
[0026] With respect to the manufacture of the Axxia products disclosed in its prior patents and applications, the array of 3-D nozzles of this invention is capable of depositing one or more types of materials during at least a portion of at least one layer-by-layer step in the product building process. The number of different types of materials deposited by the array during any one layer deposition is dependent upon, inter alia, the composition and the geometric design of the final product. Where more than one material is deposited on a particular layer, the different materials may be deposited simultaneously (either as a mixture or by separate nozzles) or sequentially.
[0027] If deposited sequentially, a portion of the previously deposited materials in that layer may be removed prior to the subsequent deposition of other materials by techniques such as etching, lasers or other means that are well known. This removal method may be beneficial with respect to the deposition of drug materials and/or the creation of openings in the implant product.
[0028] In addition, the removed portions may involve one or more layers of other materials so that an open shell of coating materials may be created into which a drug-containing matrix core may be deposited via 3-D or other methods. In that situation, for example, a drug-containing matrix core may be deposited layer-by-layer via 3-D printing within the open shell of the outside coating structure prior to the deposition of the top coating layer(s) of the implant product. In that situation, the matrix core may be created, inter alia, by having one or more 3-D nozzles (i) deposit a mixture of the drug and non-drug materials; (ii) separately deposit the drug and non-drug materials; or (iii) deposit ultra-high pressure carbon dioxide as a part of the non-drug materials in order to create an in situ foaming material that may enhance interconnective microporosity. The drug/non-drug material may be mixed homogeneously or non-homogeneously.
[0029] Alternatively, instead of creating the matrix core within the open shell of coating materials, the matrix core may be created separately and then mechanically or otherwise inserted within the open shell.
[0030] Furthermore, the matrix core structure and/or its drug release pattern may be enhanced (with respect to one or more of the layer-by-layer depositions) by first depositing only the non-drug containing material, then removing portions of that material and then depositing the drug containing material. In that circumstance, the matrix core material and/or the opening material may be deposited sequentially. For example, one or both of these materials may be deposited after another interim or temporary material has been deposited and then removed. This approach has the potential advantage of more precisely controlling the narcotic drug release pattern via micro-channels within the matrix core and the opening in the implant device.
[0031] In yet another embodiment of the invention, a rapidly biodegradable material may be used to form all or part of the opening in the implant device. This may have the advantage of an improved hygienic product and/or to control the initial drug burst if, for example, one wanted to begin drug release several days after implantation.
[0032] Similarly, a biodegradable material may be used to form all or part of the implant which, for example, obviates the need to physically remove the spent implant. Further, biodegradable material may be used to form all or part of the non-drug portion of the core. This may serve to improve the control release of the drug materials from the core.
[0033] The present invention also contemplates a high-speed and cost-efficient 3-D printing-based manufacturing process for building incremental components into finished drug delivery implant platforms. This process involves multiple pass or sequential deposition of the same or different functional materials including active pharmaceutical ingredients wherein at least portions of some or all layers can be brought to a final physical product state using ultraviolet (UV) radiation or using other means.
[0034] More specifically, this radiation may instantly cross link the functional layers without the need for thermal assist, thereby allowing for high speed operations while eliminating the possibility of thermal decomposition to the component materials. In that regard, UV curing systems are small, portable, highly efficient and inexpensive compared to thermal curing or drying ovens. UV cross linkable formulations are 100% solids liquids going into the printing process. No solvent is necessarily required so there is no need to incur the expense of recovering or burning such a process aide that ultimately doesn't become part of or add any value the final product.
[0035] In addition, the present invention contemplates the situations where (a) the process involves the use of a 3-D printing process alone or (b) in combination with (i) an non-3-D inkjet process, (ii) a non-inkjet process, (iii) a combination of those two processes or (iv) a combination of one or more of those processes with one or more other non-printing processes (such as extrusion). For example, in the combination situation, it may be preferable to use an inkjet printer process to deposit certain materials and to use a non-inkjet printer process (or a non-printing process) to deposit other materials.
[0036] As indicated above, the present invention covers the situation where the 3-D printing method is used to create all or only a portion of the controlled release medical implant product. As a result, the invention contemplates the situation where one or more layers or where one or more parts of layers are created by non-3-D methods. For example, all or part of the matrix core may be created via 3-D printing with all or part of the core, coating and/or opening created by other processes.
[0037] Further, it should be understood that the process may be used to deposit multiple layers having the same or different thicknesses. In that regard, the dimensions of medical implant devices can vary widely,
[0038] However, the implant device envisioned by this invention may be about the size of a shirt button or smaller. Thus, very approximate dimensions are about 0.5 to 25 mm in height and about 3 to 130 mm in length/diameter. Nevertheless, in the case of a large patient (e.g., a horse), the dimensions in height and/or length/diameter may be much larger. See, e.g., the discussion of the effects of these dimensions as set forth in the aforesaid Axxia prior patents and patent applications.
[0039] In addition, 3-D printing may be used to create radio opaque markers (as very generally described in Axxia prior patent application Ser. No. 2008/011908).
[0040] By utilizing the present 3-D invention, the thickness of an individual layer deposited via a 3-D printing machine can be as thin as about 0.01 mm or less. Examples of commercially available industrial 3-D printing equipment and software can be readily obtained via the Internet. See, for example, the websites of Stratasys, Organo Holdings, 3D Systems, Fortus, Daussault Systems, Autodesk and others.
[0041] The present invention is not limited to any specific 3-D printing machine or software. In other words, there is no preferred 3-D equipment or software.
[0042] By way of example only and with respect to the only ultimate products disclosed in the Axxia prior patents/applications identified above, the implant has an impermeable outer coating that surrounds a drug/non-drug matrix core. After implantation, the drug material is released on a controlled basis through one or more openings in the coating material to the mammalian (human or animal) patient.
[0043] As a result, one layer of the present implant may contain only one type of material (e.g., a coating material) as well as an opening. However, another layer of the present implant may contain multiple types of material (e.g., coating, EVA or TPU, and drug materials) as well as an opening.
[0044] In other words, the process of the present invention may be used to create not only the core (the interior drug containing matrix material) of the implant described in the Axxia patents/applications but also the openings and/or the micro-channels within the core that in combination facilitate release of the drug from the matrix core into one or more openings which lead to the exterior of the implant and from which the drug is released.
[0045] It is believed that one potentially important feature of the present process may be the creation of a strong or an improved bond (via chemical, mechanical and/or other means) between the coating and the matrix core materials. Thus, for example, a separate bonding material can be used between the outside coating material and the matrix core.
[0046] Alternatively, a very thin or ultra thin layer or portion of a layer composed of the coating material and the non-drug containing matrix material may be formed via 3-D printing (either simultaneously or sequentially). These materials can be separated deposited via different nozzles or they can be deposited together as a mixture via the nozzles. This may result in a strong or an improved bond.
BRIEF DESCRIPTION OF THE DRAWINGS
[0047] FIG. 1 is a perspective view of an exemplary embodiment of a product made by the process of the present invention. The size and dimensions of the product have been exaggerated for illustrative purposes.
[0048] FIG. 2 is a cross-sectional view of the product in FIG. 1 along line 2 - 2 . The size and dimensions of the product have been exaggerated for illustrative purposes.
[0049] FIGS. 3A , 3 B, 3 C, 3 D and 3 E illustrate in cross-sectional, partial views along line 2 - 2 some (but not necessarily all) of the processing steps required to fabricate the products of FIGS. 1 and 2 . Once again, the size and dimensions have been exaggerated for illustrative purposes. In addition, the size, location and number of 3-D printing nozzles have been exaggerated for illustrative purposes.
[0050] FIG. 4 illustrates the use of a mold (that can be reusable or not) to serve as the boundary between individual implant devices. The dimensions of the mold in this drawing also have been exaggerated for illustrative purposes.
[0051] FIG. 5 illustrates the creation of an implant where more than the core contains more than one drug.
DETAILED DESCRIPTION
[0052] The present invention covers a wide variety of 3-D printing processes that may be used to create virtually any implant or non-implant device. Therefore, the selection and description of a particular implant/non-implant device or a particular 3-D process for illustrative purposes is not intended to limit the scope of the invention.
[0053] In that regard, the implant device in FIGS. 1 and 2 is prior art, see Axxia U.S. Pat. No. 6,126,956. That implant structure is used solely for illustrative purposes and it is not intended to limit the scope of this invention because the invention covers any implant device manufactured in whole or in part via a 3-D printing process.
[0054] Turning to FIG. 1 , an abuse deterrent, subcutaneous implant 2 permits the controlled release of self-contained drug materials. A self-contained drug implant means that all of the drug materials are within the implant prior to being implanted into the patient. The phrase is intended to distinguish medical devices (such as a pump) wherein additional drugs are introduced into the patient via the device after the device has been implanted into the patient.
[0055] Implant 2 typically will have a top 4 , a bottom 6 and an outside wall 8 . Although FIG. 1 illustrates implant 2 in a button-like or cylindrical shape, virtually any geometric shape can be constructed, if desired. An opening 10 permits the controlled release of the drug—whether a narcotic or non-narcotic drug.
[0056] Although FIG. 1 shows one opening 10 , it also is possible that one or more openings could be used with respect to an implant containing more than one drug having different release rates. Typically, however, one opening can be used with respect to the release of more than one drug. See FIG. 5 discussed below.
[0057] In addition, all or part of opening 10 may contain removable materials. For example, the opening may contain rapidly biodegradable substances so that the opening is not complete until after insertion into the human or animal at which time this rapidly biodegradable material will be absorbed or will otherwise disappear in the human or animal. Examples of such a rapidly biodegradable material include, inter alia, “Biodegradable Polymer Implants to Treat Brain Tumors,” Journal of Controlled Release 74 (2001) 63-67; and “An Introduction to Biodegradable Polymers as Implant Materials,” White Paper from Inion OY (2005).
[0058] If a rapidly biodegradable material is used to create temporary plugs at the portions of the opening 16 at and near the top and the bottom of implant 2 it may be desirable to fill the remainder of the opening with a different rapidly biodegradable material, such as water or saline. In that situation, the plug portion of the rapidly biodegradable material may be selected from suitable materials so that the plug will rapidly degrade after implantation—but not during normal production, transportation or handling.
[0059] Of course, alternatively the opening may be filled with non-biodegradable materials in during the 3-D manufacturing process so long those materials are removed prior to being implanted in the patient.
[0060] FIG. 2 , shows the cross-sectional view of the product in FIG. 1 along line 2 - 2 . The top, bottom and side walls create an impermeable coating 12 . Within coating 12 , is a controlled release matrix core 14 containing both drug and non-drug material. By virtue of 3-D printing the structure of this matrix core and its release pattern may be controlled very precisely. Matrix core 14 has an uncoated wall 16 within implant 2 that abuts opening 10 in order to permit the desired controlled release of the drug to the patient.
[0061] Coating 12 may be made up of one or more materials. Some examples of coating materials include, but are not limited to, polymers, plastics, thermoplastics, EVA, TPU and silicone.
[0062] Coating 12 should be impermeable in at least two ways. First, it must be impermeable in terms of prohibiting the flow of the drug material from the matrix core 14 other than via designed openings.
[0063] Second, it must be impermeable in the sense that it has a high breaking strength. U.S. Pat. No. 8,114,383 indicates that the breaking strength should be at least 500 N. However, it is believed that a lower breaking strength (such as about 250 N) is still sufficiently high so as to be commercially acceptable.
[0064] In addition, the present invention also contemplates the optional use of a bonding material between coating 12 and matrix core 14 . These bonding materials are well known and they are preferably chosen on the basis of the coating and core materials.
[0065] If the coating and non-drug matrix core materials consist of EVA, TPU and/or silicone, any suitable materials may be selected. Further, the bonding material may be created from a mixture of the coating material and the matrix core material.
[0066] If the bonding material is sufficiently impermeable, then coating 12 need not be impermeable.
[0067] As described above, matrix core 14 contains both a drug and non-drug material. In the drug abuse field, the drug will involve a narcotic, See, U.S. Pat. No. 8,114,383, col. 2, 1. 45 to col. 5, 1. 32 for a partial listing of narcotic drugs.
[0068] In the drug compliance, pain management and animal health fields, the drug may be narcotic and/or non-narcotic.
[0069] The currently preferred process involves the use of just 3-D printing methods (but it does not exclude the use of some non-3-D printing steps). Thus, FIGS. 3A to 3E illustrate only a 3-D printer process for the manufacture of medical implant devices.
[0070] FIG. 3A illustrates the first step in the preferred embodiment of the 3-D printing process. In this preferred embodiment, the entire implant 2 is built solely via 3-D printing. However, as described above, the present invention only requires that at least a portion of one layer of the implant device be made via 3-D printing. Thus, the invention covers the use of a 3-D printing process with other processes for making an implant.
[0071] Stage 10 is the product building platform upon which the medical implant 2 device will be built via a very thin or ultra thin layer-by-layer 3-D printing deposition process. As currently envisioned, there will be at least three layer-by-layer depositions.
[0072] Stage 10 may be stationary. If stage 10 is stationary, then one 3-D process design involves the use of multiple arrays of nozzles for the layer-by-layer deposition of materials. In that situation, the stationary product building stage 10 utilizes multiple movable arrays of nozzles capable of depositing each layer or a portion of each layer. Thus, each separate array of nozzles can be designed to deposit one or more layers of materials for building the implant device.
[0073] Although it is conceivable that a single array of nozzles can be used to deposit different materials via one or more of the nozzles in that single array, it is presently contemplated that the use of multiple arrays of nozzles will be more commercially acceptable in terms, for example, of the potential problems that may arise where more than one material is deposited by an individual nozzle at various layer steps of the layer-by-layer building process.
[0074] Currently, a non-stationary stage 10 is preferred. In that situation, the product may be built layer-by-layer by moving it along a path having more than one array of nozzles. This product building path may consist of one chamber or more than one chamber,
[0075] To ensure a high degree of product purity, the use of multiple “clean” chambers may be desirable. Thus, for example, a separate chamber may be desired for (a) the layer-by-layer construction of the bottom coating/opening/coating layer, (b) the layer-by-layer construction of the coating/core/opening/core/coating layer and (c) the layer-by-layer construction of the top coating/opening/coating layer.
[0076] Further, separate chambers may be desirable with respect to the optional bonding layers between (i) the top layer of the bottom coating and the bottom layer of the matrix core and (ii) the bottom layer of the top coating and the top layer of the matrix core. See FIGS. 3B and 3D .
[0077] FIG. 3A also illustrates a bottom coating layer 12 of the implant 2 device being deposited on stage 10 . Bottom coating layer 12 contains one or more impermeable coating materials 14 . In addition, this layer contains an opening 16 or opening materials (that will later be removed in whole or in part to create an opening during manufacture). In the preferred embodiment, bottom coating layer 12 is created via an array of 3-D printing nozzles 18 , only some of which are illustrated in FIG. 3A .
[0078] As indicated above, the size of the controlled release medical implant 2 can vary. For example, the implants may be the size of a shirt button or smaller. However, the implants may be larger, depending upon the particular application, the desired controlled release rate and/or the size of the patient (e.g., a large horse).
[0079] The use of a 3-D printing method permits a considerable variation in the thickness of the materials being deposited on a specific layer and it also permits considerable variation in thickness of the various layers being deposited. Thus, for example, on the very first layer-by-layer deposition shown in FIG. 3A , bottom coating layer 12 has one thickness and opening 16 has no thickness.
[0080] Similarly, bottom coating layer 12 can be built in one or more layer-by-layer depositions. If there is more than one such deposition, the depositions may be of the same or different thicknesses. If more than one layer is deposited, then the choice of coating materials and their composition % may vary.
[0081] FIG. 3B illustrates the situation where one or more layers of coating 12 have been deposited so that the desired thickness of the coating material has been achieved. FIG. 3B also illustrates the next different process step wherein an optional bonding layer 20 is deposited.
[0082] Although bonding layer 20 may be a single material that is different from the coating material 12 or the matrix core material 22 , FIG. 3 illustrates the situation, where the bonding layer is composed of the coating material and the matrix core material. More specifically, in this preferred embodiment, the bonding material is a mixture of the coating material 14 and the non-drug matrix core material 22 . FIG. 3B shows this mixture being deposited simultaneously via 3-D printer nozzles. However, it also is contemplated that the nozzles 18 may deposit the coating and matrix core materials separately (either at the same time or sequentially).
[0083] Alternatively, the bonding material may be composed, in whole or in part, of different materials so long as the bonding material ensures sufficient adhesion between the coating materials 14 and the matrix core materials 20 .
[0084] As with all of the layers in this process, the thickness of the bonding material layer may be varied depending upon the design requirements of the implant 2 device. FIG. 3B illustrates the deposition of only one layer of bonding materials. However, more than one layer may be utilized. If more than one layer is deposited, then the choice of bonding materials and their composition % may vary.
[0085] FIG. 3C illustrates the deposition of the first layer of the matrix core 24 . The matrix core 22 is made from the matrix core materials 22 that are selected when designing the composition and structure of the implant 2 . In the preferred embodiment, the matrix core materials 24 are deposited via 3-D nozzles 18 in the form of a mixture of drug and non-drug materials (as, for example, described in the mixture of materials disclosed in Axxia's prior patents and applications). The particular % composition of this mixture can be varied to meet the desired specifications for the implant 2 . Further, these materials may be deposited homogenously or non-homogeneously depending upon the design of the desired micro-channels.
[0086] However, it also is envisioned that the drug and non-drug materials forming the matrix core may be deposited separately via nozzles 18 that deposit only one of these materials. The overall matrix core structure of such a deposition process is believed to provide potentially enhanced drug release profiles because specifically defined micro-channels can be designed via such a deposition process.
[0087] FIG. 3C also shows optional bonding layer 20 .
[0088] FIG. 3D illustrates the situation where one or more layers matrix core materials 20 have been deposited so that the desired thickness of the matrix core 22 has been achieved. FIG. 3D also illustrates the next different process step wherein another optional bonding layer 20 is deposited. The comments with respect to FIG. 3B are generally applicable here.
[0089] FIG. 3D shows where optional bonding layer 20 is being deposited via 3-D printer nozzles. As a result, optional bonding layer 20 surrounds the matrix core 22 . If more than one layer is deposited, then the choice of bonding materials and their composition % may vary.
[0090] FIG. 3E illustrates the situation where one or more layers of coating material 14 have been deposited via a 3-D printing process so as to create the top portion of coating layer 12 . If more than one layer is deposited, then the choice of coating materials and their composition % may vary.
[0091] As discussed above, the preferred embodiment creates an opening 16 during the manufacture of implant device 2 . However, the present invention also contemplates the situation where materials are inserted into opening 16 on an interim or temporary basis during the 3-D manufacturing process. However, as explained herein, these materials will typically be entirely removed prior to implanting the device into the patient.
[0092] Thus, with respect to non-biodegradable materials, all of those materials should be removed prior to implanting via well known means such as etching, mechanical means (such as perforation or drilling), chemical means, lasers or the like. At the present time, it is the inventors' opinion that chemical means appear to be the least commercially viable because they may have the potential effect of interfering with the drug materials in the matrix core 22 and/or of interfering with the controlled drug release.
[0093] Alternatively, rapidly biodegradable materials may be utilized within the opening. These materials may be entirely removed via the means set forth above.
[0094] However, it also is envisioned that a small portion of the rapidly biodegradable materials may be left within the opening 16 so that this portion will quickly disappear after being implanted in the patient. The remaining rapidly biodegradable material may be in the form of a thin plug at the ends of the opening and/or a thin coating along the sidewalls of the opening.
[0095] In another embodiment of the invention, the outside shape of the medical implants or non-implants can be constructed by having each layer created within an existing outside mold or the like. This may be beneficial with respect to spherical, non-cylindrical and/or non-flat shapes.
[0096] FIG. 4 illustrates a situation where an outside mold 26 may be utilized to enhance the rapid production of large numbers of implants. In one example of a mold 26 , a matrix mold has curved mold walls 28 that assist in building large numbers of implants.
[0097] In this preferred embodiment the mold is re-usable and an individual implant device 2 is created within the separate walls 28 of mold 26 . The walls of mold 26 may be designed so that they create the appropriate shape for the implants. In addition, the walls 28 may be coating with an appropriate material so that, upon removal from stage 10 , the implants are easily removed from the mold (e.g., by gravity).
[0098] Alternatively, the mold may be non-reusable. For example, a thin mold wall may be created so that it becomes a part of the implants being manufactured. Then, after 3-D processing is complete, the individual implants may separated from each other at the by using laser or other cutting means to remove all or part of the mold.
[0099] In that situation, mold 26 may be created prior to the 3-D printing process. On the other hand, it also is envisioned the nozzles 18 can be used to create/build such a non-reusable mold during the implant manufacturing process.
[0100] Thus, it is contemplated that, as with semiconductor manufacturing where large numbers of individual semiconductors are created at one time during processing, implants 12 may be created in very large numbers by the present invention. Subsequently, as described above, the individual implants may be separated by mechanical means (e.g., cutting via lasers or blade mechanisms) or by other means (e.g., via chemical etching or otherwise removing the undesired portions). Also, as described above, reusable or non-reusable matrices may be used to create large numbers of implants.
[0101] Although the preferred embodiment in FIG. 3 do not utilize any non-3-D printing steps, the present invention does not mandate that only 3-D printing steps are used to make the medical implant or non-implant devices. Instead, it only requires that a 3-D printing process is used to make at least a portion of one or more layers of the devices.
[0102] An example of this includes the situation where a sheet of the coating layer material 14 is laid upon a stage 10 . See FIG. 3A . This coating material may be part or all of bottom coating layer 12 . Thereafter, the implant device 12 is generally built in accordance with FIGS. 3B to 3E . Thus, where many implants are built upon this sheet of material, the individual implants may be separated from each other via laser or other means. Similarly, the openings may be created either via (a) laser or other means or (b) non-deposition in the openings area when practicing the invention.
[0103] Another example is where the matrix core material is made in whole or in part via 3-D printing. This matrix core can be embedded with a coating layer made by any number of means—such as 3-D printing, extrusion, shrink wrap, spray et cetera. Thereafter, an opening may be created by any of the means described herein or otherwise known to one of ordinary skill in the art.
[0104] In addition, it should be understood that the materials in any particular layer (e.g., the coating and matrix core layers) may vary within that layer due to the thin and very thin nature of the 3-D printing method.
[0105] Moreover, as mentioned above, the implant may contain more than one drug. FIG. 5 illustrates one example of such an implant. This embodiment shows a “double decker” implant design. Implant 2 has a coating 12 that essentially surrounds two cores 14 . Implant 2 also has an opening 19 with uncoated walls 16 . In this embodiment, different drug materials 30 , 32 are contained in the two cores 14 . Of course, it is possible to have more than just two drugs within the implant by, for example, have more than two cores.
[0106] As may be readily appreciated by those of skill in the manufacture of medical implant or non-implant device art, the present invention can be practiced other than as is specifically disclosed herein. Thus, while the invention has been described generally and with respect to certain preferred embodiments, it is to be understood that the foregoing and other modifications and variations may be made without departing from the scope or the spirit of the invention.
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A multi-step method of making a mammalian subcutaneous medical implant for releasing self-contained drugs on a controlled basis over at least a 3 day period includes depositing at least portions of one or more individual layers of the implant by at least one computer controlled 3-D printer. The 3-D printing method may be accomplished via an array of 3-D nozzles that deposit materials (such as plastics, thermoplastics, coating materials, drug-containing matrix materials, non-drug containing matrix materials, bonding materials, biodegradable materials and/or the like) in very small, precise portions. The materials may be deposited in liquid, powder, sheet or other forms. Non-implant forms may also be provided by the techniques disclosed herein.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] In one of its aspects, the present invention relates to an on-line device for predicting at least one fluid flow parameter in a process. In another of its aspects, the present invention relates to an on-line UV dosimeter for predicting bioassay equivalent does for a given microorganism in a UV disinfection process. In yet another of its aspects, the present invention relates to a method for on-line prediction of at least one fluid flow parameter in a process.
[0003] 2. Description of the Prior Art
[0004] Fluid treatment systems are known generally in the art.
[0005] For example, U.S. Pat. Nos. 4,482,809, 4,872,980 and 5,006,244 (all in the name of Maarschalkerweerd and all assigned to the assignee of the present invention and hereinafter referred to as the Maarschalkerweerd #1 patents) all describe gravity fed fluid treatment systems which employ ultraviolet (UV) radiation.
[0006] Such systems include an array of UV lamp frames which include several UV lamps each of which are mounted within sleeves which extend between and are supported by a pair of legs which are attached to a cross-piece. The so-supported sleeves (containing the UV lamps) are immersed into a fluid to be treated which is then irradiated as required. The amount of radiation to which the fluid is exposed is determined by the proximity of the fluid to the lamps, the output wattage of the lamps and the fluid's flow rate past the lamps. Typically, one or more UV sensors may be employed to monitor the UV output of the lamps and the fluid level is typically controlled, to some extent, downstream of the treatment device by means of level gates or the like.
[0007] U.S. Pat. Nos. 5,418,370, 5,539,210 and 5,590,390 (all in the name of Maarschalkerweerd and all assigned to the assignee of the present invention and hereinafter referred to as the Maarschalkerweerd #2 patents) all describe fluid treatment systems which employ UV radiation. More specifically, the Maarschalkerweerd #2 patents teach an ultraviolet radiation treatment system disposed in an open channel comprising a gravity fed flow of fluid. In a preferred embodiment, after treatment, the fluid is then discharged into a stream, creek, river, lake or other body of water—i.e., this embodiment represent application of the system in a municipal wastewater treatment facility.
[0008] Conventionally, in the art of UV radiation treatment systems, the radiation dose in a given irradiation zone has been calculated using the equation:
DOSE= t ave ×I ave
[0009] wherein t ave is the average time that a microbe spends in the irradiation zone and I ave is average UV intensity integrated over the volume in the irradiation zone.
[0010] Recently, it has been suggested that this relatively simple calculation can, in certain cases, lead to inaccuracies in the dose which is actually delivered to the fluid being treated—see “Hydrodynamic behaviour in open-channel UV systems: Effects on microbial inactivation” (K. Chiu, D. A. Lyn, and E. R. Blatchley III, CSCE/ASCE Environmental Engineering Conference (1997), pages 1189-1199). This can have significant consequences since many UV radiation treatment systems are specified in large part using such a calculation. Further, the calculation presumes that the system is operating in an optimum state at all times and thus, for example, would not take into account a situation where one or more of the UV radiation sources is not operating properly or at all.
[0011] Accordingly, there remains a need in the art for a device which would allow one to predict with improved accuracy the dose delivered to the flow of fluid. It would be advantageous if such a device had widespread use beyond that in predicting dose delivered to a flow of fluid in a UV radiation treatment system—i.e., beyond use as a dosimeter.
SUMMARY OF THE INVENTION
[0012] It is an object of the present invention to obviate or mitigate at least one of the above-mention disadvantages of the prior art.
[0013] It is another object of the present invention to provide a novel on-line device for predicting at least one fluid flow parameter in a process.
[0014] It is another object of the present invention to provide a novel method for on-line prediction of at least one fluid flow parameter in a process.
[0015] In one of its aspects, the present invention provides an on-line device for predicting at least one fluid flow parameter in a process, the process comprising a bounded flow domain having disposed therein a pre-determined matrix, the device comprising a computer having:
[0016] (i) a memory for receiving a database, the database comprising location information for a plurality of nodes or particle pathways in the matrix,
[0017] (ii) means to receive input data from the process, and
[0018] (iii) means to calculate the at least one fluid flow parameter from the database and the input data.
[0019] In another of its aspects, the present invention provides an on-line device for predicting at least one fluid flow parameter in a process, the process comprising a flow domain having disposed therein a pre-determined portion in which a fluid flows, the device comprising a computer having:
[0020] (i) a memory for receiving a database, the database comprising relative information in respect of a plurality of nodes or a plurality of particle pathways in the pre-determined portion;
[0021] (ii) means to receive input data from the process, and
[0022] (iii) means to calculate the at least one fluid flow parameter from the database and the input data.
[0023] In yet another of its aspects, an on-line UV dosimeter device for predicting bioassay equivalent dose for a given microorganism in a UV disinfection process, the UV disinfection process comprising a flow domain in which a fluid flows, the device comprising a computer having:
[0024] (i) a memory for receiving a database, the database comprising relative dose information in respect of a plurality of fluid pathways through the flow domain;
[0025] (ii) means to receive input data from the process, the input data selected from the group comprising UV transmittance of the fluid, flow rate of the fluid and intensity field in the fluid domain; and
[0026] (iii) means to calculate the bioassay equivalent dose for the given microorganism from the database and the input data.
[0027] In yet another of its aspects, the present invention provides a method for on-line prediction of at least one fluid flow parameter in a process, the process comprising a flow domain having disposed therein a pre-determined portion in which a fluid flows, the method comprising the steps of:
[0028] (i) storing in a memory of a computer a database, the database comprising relative information in respect of a plurality of nodes or a plurality of particle pathways in the pre-determined portion;
[0029] (ii) obtaining input data from the process;
[0030] (iii) conveying the input data to the computer; and
[0031] (iv) calculating the at least one fluid flow parameter from the database and the input data.
[0032] A fundamental understanding of a chemical, photochemical or biological process is key to predicting and controlling the process' outcomes. Most of these types of processes involve fluid flow, and the behaviour of the fluid can significantly affect the efficiency of the process. The better the understanding of the fluid flow, the better the process prediction and control.
[0033] An advantage of the present invention is an online prediction of at least one fluid flow parameter such as velocity, pressure, temperature and turbulence parameters calculated preferably by computational fluid dynamics (CFD) and coupled with certain relevant parameters measured online at discrete points in the process of interest. If all of the relevant flow parameters are known throughout the flow domain of interest, a much better prediction of system response can be achieved, which leads to better process control.
[0034] For example, the invention can be applied to predicting dose distribution profiles in a UV radiation fluid treatment system thereby mitigating and/or obviating the above-mentioned disadvantages of the prior art. Of course, those of skill in the art will recognize that the present invention may be used in a variety of other applications such as photochemical processes, chemical processes, biological processes and the like.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] The present device comprises a computer. The computer includes a memory for receiving a database.
[0036] The database comprises location information for a plurality of nodes in the matrix. The database may be obtained by determining the distribution of flow parameters within a flow domain (e.g., a channel or pipe for containing a fluid in the process of interest). This can be achieved on-line or off-line.
[0037] If the database is obtained off-line, there are two general techniques which may be used. The first comprises “direct measurement” using techniques such as Laser Doppler Anemometry, Hot Wire Anemometry and Particle Image Velocimetry. The second comprises “numerical/computational techniques”, typically referred to as CFD (Computational Fluid Dynamics)—see, for example, “An introduction to Computational Fluid Dynamics” by Versteeg et al. (1995).
[0038] If the database is obtained on-line, it is preferred to use numerical/computational techniques. More detail on these techniques may be obtained from one or more of:
[0039] 1. “Hot Wire Anemometry”, G. Compte-Bellot, Annu. Rev. Fluid Mech., vol.8, pp.209-231 (1976);
[0040] 2. “Laser Velocimetry”, Ronald J. Adrian, Chapter 5 in “Fluid Mechanics Measurements”, Edited by Richard J. Goldstein, 1983;
[0041] 3. “Digital Particle Image Velocimetry”, C. E. Willert and M. Gharib, Experiments in Fluids 10, 181-193 (1991);
[0042] 4. TSI Inc. at the website: “http://www.tsi.com/”;
[0043] 5. DANTEC Measurement Technology at the website: “http://www.dantecmt.com/”;
[0044] 6. Fluent5 Users Guide. Fluent Incorporated, Lebanon, N.H., USA; and
[0045] 7. Versteeg, H. K. and W. Malalasekera. An Introduction to Computational Fluid Dynamics. Longman Group Ltd., 1995.
[0046] In the preferred application of the present invention (i.e., a UV dosimeter), the database which is stored in the memory of the computer should include location information for each of a plurality of nodes in the pre-determined matrix in the bounded flow domain. Preferably, the location information for each node includes: spatial position of the node, velocity vector components, pressure and some measure of turbulence, such as the turbulence kinetic energy and the turbulence dissipation rate.
[0047] The preferred approach for determining the flow parameters within the flow domain by direct measurement is to establish a database of the parameters by measuring them throughout the domain a priori (e.g., off-line), under conditions that are similar to those experienced in the process of interest. In the case of a UV disinfection reactor, for example, the velocity, pressure and turbulence parameters could be measured at node locations of a fine three-dimensional grid (i.e., the matrix) within the reactor under flow rates relevant to operating conditions for the reactor. By repeating the measurements for different volume flow rate conditions, a database representative of varying flow conditions can be established. Essentially, the database consists of the x, y, z positions of nodes representing physical measurement locations, and for each different volume flow rate, the relevant flow parameters (velocity, pressure, turbulence intensity . . . ) measured at each node.
[0048] The preferred approach for determining the flow parameters within the flow domain by numerical/computation techniques is to use CFD. By modelling the flow within a reactor on a computer, a suitable database comprising the necessary location information can be established.
[0049] Whether the database comprising the necessary location information is established experimentally or numerically, it is desirable that it be correlated to the on-line conditions. This is accomplished by measuring relevant bulk flow parameters. In the case of a UV disinfection reactor, the relevant parameter would most likely be volume flow rate. In the case of an online CFD system, a new database comprising location information could be generated as the volume flow rate changes. On the other hand, if the database comprising the location information was generated offline (using CFD or direct measurement) then interpolation or scaling techniques could be used to closely approximate the on-line conditions from the conditions available in the database.
[0050] Once the flow through the reactor has been determined for the given on-line conditions, transport equations can be solved to determine relevant process functions (as mentioned above). In the application of the invention to a UV disinfection reactor, the interest lies in reactor performance, or specifically reactor inactivation of target pathogens. Biological inactivation can be modelled as a function of applied UV dose using equations that consider first order kinetics, particle association of microbes, and microbial repair processes.
[0051] Under first order kinetics, biological inactivation can be modelled by
N N o = - kD ( 1 )
[0052] where N O is number of viable microbes before disinfection and N is the number of viable microbes after disinfection. The constant k is dependent on the type of microbe being inactivated and D is the dose delivered. Dose is defined as the germicidal intensity versus exposure time. In a real reactor, the UV intensity will vary with spatial position within the reactor (less UV intensity in regions farther from the lamp) and with the UV Transmittance (UVT) of the water. Since the position of the lamps is known (the geometry of the reactor is known) and the UVT can be measured online, the intensity field within the reactor can be calculated and correlated with online sensor readings. As microbes move through the reactor, due to the motion of fluid (water in this case), they will pass through the intensity field. Clearly the path of a microbe will experience varying degrees of intensity as it moves through the reactor. The integration of the intensity field with the path travelled and UV exposure time will yield a dose value for each microbe.
[0053] A UV reactor will have an infinite number of path lines that microbes will track, with each distinct path receiving a distinct dose, D i . Since a reactor will have an infinite number of paths that a microbe could follow, the net reactor inactivation can be written as
N N o = ∑ i = 1 ∞ f i - kD i ( 2 )
[0054] where f i is the fraction of particles receiving a dose D i , such that
∑ i = 1 ∞ f i = 1.
[0055] Reactor inactivation can be modelled as
N N o = - kD eqv ( 3 )
[0056] where N O is now the flux of viable microbes upstream of the reactor (or the total number of viable microbes in the case of a collimated beam study) and N is the flux of viable microbes downstream of the reactor, after disinfection. D eqv is the dose delivered by the reactor.
[0057] The “dose” that the reactor delivers, or the “equivalent dose”, can be determined by combining Equations (2) and (3) to give
N N o = - kD eqv = ∑ i = 1 ∞ f i - kD i
or ( 4 ) D eqv = - 1 k ln [ ∑ i = 1 ∞ f i - kD i ] . ( 5 )
[0058] Essentially, reactor performance is determined by integrating all of the microbial paths through the reactor. Computationally, this can be determined from the database comprising the location information for each node. Two conventional CFD methods exist which may be used to accomplish this task:
[0059] 1. Eulerian/scalar approach, and
[0060] 2. Lagrangian particle tracking approach.
[0061] In the Eulerian approach, dose, D, is treated as a scalar, and the equation for scalar transport integrated with the intensity field and the database comprising the location information can be used to determine a dose distribution at the reactor outlet. Integration of the outlet dose distribution with the outlet volume flow rate fraction and Equation (5) will give a reactor performance value based on the target organism inactivation constant, k. The difficulty with the Eulerian approach is that the scalar equations account for diffusion and turbulent mixing which averages out the dose. In reality, each microbe is a discrete entity and should be treated as such and thus should not be averaged. Commercial CFD software can be used to implement the equations quite readily—see, for example the operators manual for Fluent™ CFD software. It should be emphasised that both numerically and experimentally generated database comprising the location information can be used with conventionally CFD software.
[0062] The preferred approach is to use Lagrangian particle tracking. With this approach, the database comprising the location information for each node is used to determine the motion of discrete particles through the reactor. The particle path can be integrated with the known intensity field to determine the delivered dose to each particle. Each particle will have its own path and while no two paths will be identical, a sufficient representation of dose distribution can be achieved by calculating the paths of, for example, 100 particles. In this approach, Equations (4) and (5) can be used directly, with the upper limit of the summation set to n, where n is the number of representative particle paths, and f i =1/n.
[0063] In a preferred embodiment of the invention, the database comprises location information for a plurality of particle tracks in at least a portion of the matrix (i.e., instead of location information for a plurality of nodes throughout the matrix). Thus, the database is obtained independently of the intensity field. In other words, instead of storing of the database comprising the location information online, the database can be used to establish a database of particle tracks a priori, and only the particle tracks need to be stored on-line. This enhancement reduces the computational effort even further.
[0064] As indicated hereinabove, a fundamental understanding of a chemical, photochemical or biological process is key to predicting and controlling the outcomes of the process. For example, the present invention can be applied to predicting disinfection performance in a UV radiation fluid treatment system thereby mitigating and/or obviating the above mentioned disadvantages of the prior art. More specifically, a preferred embodiment of the present on-line device is a UV dosimeter used to predict the bioassay equivalent dose in a given UV disinfection system and process.
[0065] In this preferred embodiment of the present device, the database comprises of dose data for a plurality of virtual particles passing through a UV disinfection process, where each virtual particle may represent a microbe, a aggregation of microbes and other matter, or a molecule of a chemical. The dose for each virtual particle as it passes through the reactor may be determined by integrating the UV intensity experienced by the particle over the path the particle travels through the UV disinfection process. Mathematically, such a relationship may be expressed as:
D i = ∫ t = 0 t = t r I ( x , y , z ) t
[0066] wherein:
[0067] D i is the UV dose in mJ/cm 2 experienced by the i th virtual particle after it has traveled through the UV disinfection process;
[0068] I(x,y,z) is the UV intensity in mW/cm 2 experienced by the particle at position (x,y,z) on its path through the UV disinfection process; and
[0069] t is the time in seconds where t=0 represents the time the particle enters the UV disinfection process and t=t r represents the time the particle leaves the UV disinfection process.
[0070] The path the virtual particle travels as it passes through the reactor may be determined by “direct measurement” using techniques such as “Laser Doppler Anemometry, Hot Wire Anemometry or Particle Image Velocimetry. Or the path may be predicted using “numerical/computational techniques”, typically referred to as Computational Fluid Dynamics (CFD). Those skilled in the art will recognize that CFD techniques allow one to attribute physical characteristics to the virtual particles so as to model the effects of forces like gravity on the virtual particles.
[0071] Using these methods, the path of the virtual particles will be typically defined using a space-time coordinate system (x, y, z t) where x, y and z define a spatial 3-d coordinate system and t represents time. Those skilled in the art will recognize that radial or polar coordinate systems could be used and that symmetry considerations will allow the paths of virtual particles through some UV disinfection processes to be represented by one or two dimensional spatial coordinate systems as opposed to three dimensional systems.
[0072] Given that the paths of the virtual particles through the UV disinfection processes will typically be represented using consecutive series of space-time coordinates, the dose delivered to each particle may be written using summation notation as per:
D i = ∑ j = 1 j = k i ( I ( x j + 1 , y j + 1 , z j + 1 ) + I ( x j , y j , z j ) ) 2 ( t j + 1 - t j )
[0073] Where the path of i th particle through the UV disinfection process is represented by k i sets of space-time coordinates.
[0074] The UV intensity at position (x, y, z) within a UV disinfection processes may be calculated using standard optical techniques using either a radial intensity model as described by:
[0075] C. N. Haas and G. P. Sakellaropoulos (1979) “Rational analysis of ultraviolet disinfection”, National Conference on Environmental Engineering, Proc. ASCE Specialty Conf, San Francisco, Calif., July 9-11, pp. 540-547;
[0076] or by Point Source Summation as described by:
[0077] S. M. Jacob and J. S. Dranoff (1970) “Light intensity profiles in a perfectly mixed photoreactor”, AIChE Journal, Vol. 16, No. 3, pp. 359-363;
[0078] or by Point Source Summation modified to include refraction effects as per:
[0079] J. R. Bolton (1999) “Significance of refraction and reflection in the calculation of ultraviolet fluence rate distributions in an annular ultraviolet disinfection reactor using broadband medium-pressure mercury UV lamps”.
[0080] Those skilled in the art will recognize that a plurality of intensity models may be defined for UV disinfection processes and that each model can offer a reasonable prediction of UV intensity depending on the UV absorbance characteristics of the water being treated and the configuration of the UV reactor. The suitability of the intensity model can be tested using either measurements of UV intensity by radiometer, actinometry, or some other recognized measurements method for UV light.
[0081] In the preferred application of the present invention for a UV disinfection process using more than one UV lamp, the dose delivered to the virtual particle by each UV lamp operating at full power is calculated and stored in the database. Accordingly, if the UV disinfection process utilizes “L” UV lamps, for each virtual particle, the database contains the dose delivered to that particle by the 1 st UV lamp, the 2 nd UV lamp, and so forth up to the L th UV lamp. In one possible manifestation of the database, the information for a 3 lamp reactor may be structured as set out in Table 1.
[0082] Those skilled in the art will recognize that the path taken by each virtual particle as it passes through the UV disinfection process will depend on the flowrate and other characteristics of the water. The database may contain dose data for a plurality of flowrates through the disinfection process and a plurality of water characteristics. However, in a preferred application of the invention, only a limited number of flow conditions are stored in the database and dose values for other conditions are obtained by scaling the numbers stored. For example, dose delivered to a virtual particle at flowrate x may be calculated from the dose at flow rate y by multiplying that dose by the ratio of flowrate y to flowrate x.
TABLE 1 Flowrate Dose (GPM) UV Transmittance (%) Lamp ID Particle ID (mJ/cm2) 500 95 1 1 5 500 95 1 2 6 500 95 1 3 8 500 95 1 4 2 500 95 1 5 4 500 95 2 1 4 500 95 2 2 5 500 95 2 3 7 500 95 2 4 9 500 95 2 5 8 500 95 3 1 8 500 95 3 2 7 500 95 3 3 4 500 95 3 4 4 500 95 3 5 5
[0083] Those skilled in the art will further recognize that the intensity experienced be each virtual particle as it passes through the UV disinfection process will depend on the UV transmittance of the water being treated. The database may contain dose data for a plurality of UV transmittance values. However, in a preferred application of the invention, the dependence of dose delivered by a given lamp at a given flowrate to each virtual particle as a function of UV transmittance may be modeled using some function and the function coefficients may be stored within the database. For example, the dose delivered to a virtual particle by a given lamp at a given flowrate may be described as a function of UV transmittance ranging from 30 to 99% using a 5 th order polynomial function. In that case, the database need only contain the five coefficients associated with that polynomial function to describe dose over that UV transmittance range.
[0084] Those skilled in the art will further recognize that the UV lamps may be operating at different power levels and that their UV output may vary from lamp to lamp because of factors such as lamp aging and lamp sleeve fouling. In one manifestation of the current invention, dose delivered to each virtual particle by a given lamp may be scaled by the electrical power setting of that lamp. In another manifestation, dose delivered to each virtual particle may be scaled by the ratio of the UV intensity measured using a calibrated UV sensor to the UV intensity calculated for that sensor using the appropriate UV intensity model or expected from sensor measurements obtained using new lamps, non-fouled lamp sleeves, and non-fouled sensor detection windows.
[0085] The net dose experienced by the i th virtual particle as it passes through the UV disinfection process may be calculated by summing the contribution to that particle of each lamp within the reactor. In a preferred manifestation, the net dose per virtual particle may be calculated as per
( Net Dose ) i = Q CFD Q ∑ n = 1 n = L Dose i n ( UVT ) f n
[0086] wherein
[0087] Q CFD is the flowrate associated with the space-time coordinates of the virtual particle tracks stored in the database;
[0088] Q is the actual flowrate passing through the UV disinfection process;
[0089] Dose in (UVT) is the dose delivered to virtual particle i by lamp n at a UV transmittance of UVT; and
[0090] f n is the scaling factor for lamp n to account for lamp power setting and sensor measurements that indicate fouling or lamp aging.
[0091] In order to predict the dose delivery of the UV disinfection process, the dose delivered to a plurality of virtual particles should be calculated. The paths of the particles should start within the inlet piping upstream of the UV disinfection process. The starting location of the virtual particles within the inlet piping should be sufficiently upstream of the reactor that dose delivery to the virtual particles by the UV disinfection process is not significantly affected by moving that location further upstream. In a preferred application of the invention, the starting locations of the virtual particles lie in a plane perpendicular to the bulk flow and are uniformly distributed across that plane. Those skilled in the art will recognize that inlet piping to a UV disinfection process may vary from one installation to the next. Since the configuration of inlet piping will have an impact on the travel of the virtual particles as they pass through the UV disinfection process, an advantage of the present invention is the ability to assess site specific considerations that impact the performance of the UV disinfection process.
[0092] In a typical application of the invention, the dose delivery to greater than 250 virtual particles are determined. Those skilled in the art will recognize that no two particles will follow the same path through the UV disinfection process. Accordingly, no two particles will receive exactly the same UV dose. Accordingly, dose delivery to a UV reactor may be presented as a dose histogram. Furthermore, the dose histogram may be modeled using a probability distribution which may be combined with treatment kinetics to predict the net impact of the UV disinfection process.
[0093] The net performance of the UV disinfection process may be calculated by summing the impact of the net doses delivered to each of the virtual particles. The impact of dose may be described using kinetic equations determined using standard laboratory practice. In the case of UV disinfection, UV inactivation kinetics for a particular microbe may be determined by exposing a stirred suspension of those microbes to a collimated beam of UV light of known UV intensity. By various exposure times, various doses are applied. The kinetics of inactivation may be obtained by plotting the inactivation achieved as a function of dose delivered. A plot of inactivation as a function of dose may be modeled using first order kinetics
N/No=exp (− k Dose)
[0094] wherein:
[0095] No is the concentration of viable microbes prior to exposure to UV;
[0096] N is the concentration of viable microbes after exposure to a UV dose; and
[0097] k is the first order inactivation constant of the microbes.
[0098] Those skilled in the art will recognize that microbial inactivation kinetics do not always follow first order kinetics. In those cases a series-event model, a double exponential model or some other conventional function may be more appropriate for describing the relationship between inactivation and dose.
[0099] Given a function g(Dose) describing microbial inactivation kinetics, the net performance of the reactor may be calculated using:
N No = ∑ i = 1 i = m g ( ( Net Dose ) i ) / m
[0100] where m is the total number of virtual particles considered to have passed through the UV treatment process.
[0101] The net performance of the reactor can be associated with a dose equivalent value using the inactivation kinetics by solving:
g ( Dose Equivalent ) = ∑ i = 1 i = m g ( ( Net Dose ) i ) / m
[0102] In the case of first order kinetics, these equations could be written as:
N / No = ∑ i = 1 i = m exp ( k ( Net Dose ) i ) / m and Dose Equivalent = - ln ( ∑ i = 1 i = m exp ( k ( Net Dose ) i ) / m ) / k .
[0103] While this invention has been described with reference to illustrative embodiments and examples, the description is not intended to be construed in a limiting sense. Thus, various modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to this description. It is therefore contemplated that the appended claims will cover any such modifications or embodiments.
[0104] All publications, patents and patent applications referred to herein are incorporated by reference in their entirety to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference in its entirety.
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There is described an on-line device for predicting at least one fluid flow parameter in a process. In embodiment, the process in question comprises a flow domain having disposed therein a pre-determined portion in which a fluid flows and the device comprises a computer having: (i) a memory for receiving a database, the database comprising relative information in respect of a plurality of nodes or a plurality of particle pathways in the pre-determined portion; (ii) means to receive input data from the process, and (iii) means to calculate the at least one fluid flow parameter from the database and the input data. In another embodiment the process in question comprises a bounded flow domain having disposed therein a pre-determined matrix and the device comprises a computer having: (i) a memory for receiving a database, the database comprising location information for a plurality of nodes or particle pathways in the matrix, (ii) means to receive input data from the process, and (iii) means to calculate the at least one fluid flow parameter from the database and the input data. The device is particularly advantageously employed as a UV dosimeter.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/194,765 filed Sep. 30, 2008, which is incorporated herein by reference, and is a continuation-in-part of U.S. patent application Ser. No. 12/214,345 filed Jun. 18, 2008, which still pending and is incorporated herein by reference and which claims the benefit of U.S. Provisional Patent Application Ser. No. 60/936,425 filed Jun. 20, 2007.
FIELD OF THE INVENTION
The present invention relates to metallic encapsulation of lightweight ceramics for use in personnel and vehicular armor systems. More specifically, it relates to metallically encapsulated ceramic armor with enhanced ballistic efficiency, physical durability, multiple hit capability, structural integrity, and corrosion resistance.
BACKGROUND OF THE INVENTION
U.S. patent application Ser. No. 12/214,345, filed Jun. 18, 2008, which is still pending and incorporated herein by reference, describes a method for producing armor through metallic encapsulation of a ceramic core. In summary, this method involves first selecting a ceramic tile of the desired geometry; fabricating a conformal sheet metal container with dimensions modestly oversized relative to the ceramic tile; and placing the ceramic tile in the conformal sheet metal container and closing it. The closed conformal sheet metal container and a bed of granular material, which serves as a pressure transmission vehicle, are placed in an isostatic pressurization chamber. After the isostatic pressurization container is closed, degassed and hermetically sealed, it is subjected to temperature and pressure cycles that cause diffusion bonding of the ceramic tile and the conformal sheet metal container.
The method described in U.S. patent application Ser. No. 12/214,345 has many advantages over the prior art. It is less complicated, less costly, capable of working with a wide range of metal and ceramic materials combinations, and also compatible with the requirements of reproducible and large-scale manufacturing. However, the method requires a hot isostatic pressurizing step, or high pressure step, which is complex and expensive.
It is an object of the present invention to use lower pressure methods for bonding metals, such as titanium, aluminum and magnesium, to ceramics, such as silicon carbide, boron carbide, titanium diboride, and alumina. Lower pressure processing methods will allow the use of lower cost, much more widely available, autoclaves or brazing furnaces.
The use of these lower pressure bonding methods is based on the use of a “wetting” braze with a relatively low temperature melting point (herein defined as an “interlayer material”), as exemplified by aluminum 4047 alloy. Because it appears that an interlayer material, such as aluminum 4047 alloy, produces effective wetting of both the metal and ceramic, the relatively low melting point interlayer material produces an effective bonding. In other words, it is not necessary to depend exclusively on diffusion bonding, as it is classically carried out in a hot isostatic press, which entails use of relatively high temperatures and high pressures, to initiate plastic flow and chemical diffusional bonding at interface. In effect, a properly designed interlayer material with the right technical properties can achieve many of the same attributes that result from high pressure diffusion bonding.
The present invention is a method for joining titanium, aluminum or magnesium sheet to armor ceramics using an autoclave furnace, which works at a few hundred psi, or even a conventional brazing furnace, which works at atmospheric or slightly positive pressure. The key for making the low pressure bonding work is to have an interlayer material and a soft, ductile metallic foil “bag” (herein defined as a “metallic bag”) that can be vacuum sealed. The parts to be bonded, here a ceramic tile, an interlayer material and conformal sheet metal container, are placed in a metallic bag, the metallic bag is sealed and evacuated, and the metallic bag is placed into an autoclave or brazing furnace.
SUMMARY OF THE INVENTION
The present invention, as shown in the flow chart in FIG. 1 , is a method for producing metallically encapsulated ceramic armor. In summary, this method involves first selecting a ceramic tile 1 of the desired ceramic and geometry; fabricating 2 a conformal sheet metal container of the desired metal with dimensions modestly oversized relative to the ceramic tile; placing 3 the ceramic tile and a selected interlayer material in the conformal sheet metal container; and closing 4 the container. The closed conformal sheet metal container is placed 5 in a metallic bag. After the metallic bag is closed, degassed and hermetically sealed 6 , it is heated 7 in an autoclave or brazing furnace.
The present invention produces metallically encapsulated ceramic armor with excellent shear properties and good physical durability. Since the invention in its most basic form involves the use of commercially available sheet metal material for encapsulation, the areal density of the encapsulated armor is extremely repeatable and controllable. It is limited only by the availability of suitable sheet metal products. The articles produced from this invention can also be produced with varying degrees of lateral or hydrostatic confinement by simply varying the thickness and physical properties (i.e., coefficient of thermal expansion, elastic modulus). Other properties such as corrosion resistance and weldability can also be tailored to the engineering requirements of a given system by choosing a suitable pure metal or alloy. For example, metallically encapsulated ceramic armor with excellent corrosion resistance in marine or salt spray environments can be produced by using Grade 2 titanium or suitable alpha or beta titanium alloys as the encapsulating material, thus simplifying maintenance and logistical requirements for the armor system.
It will be understood that the present invention is not limited to being practiced with titanium, aluminum or magnesium alloys as the encapsulating material. Any metal layer that is thermodynamically compatible with the underlying ceramic tile and can be formed by standard sheet metal or similar metallurgical forming methods is a potential candidate. Among the metals that could be considered are titanium, aluminum, magnesium, steel, nickel, tantalum, zirconium or niobium. Intimate contact and bonding, the degree of which can be controlled by suitable application of processing parameters and interlayer material, is brought about by suitable temperature and pressure. The conditions needed to bond metallic encapsulating sheet metal layers, interlayer material substrates, and ceramic armor substrates are developed for each materials combination of interest, largely based on factors such as melting point.
Metallically encapsulated ceramic armor articles formed by the method of the present invention can have tailored thermal expansion and elastic modulus behavior providing for a controllable degree of lateral and/or hydrostatic confinement on the ceramic armor tiles to which they are bonded. This affords the possibility to optimize a given materials system according to the dictates of a given penetration mechanics or finite element structural model.
These and other features and advantages of the present invention will be better understood by reading the following detailed description of a preferred embodiment, taken together with the figures incorporated herein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a flow chart of the method of the present invention;
FIG. 2 shows the sheet metal forming techniques used to produce a (double) encapsulated hexagonal ceramic tile array;
FIG. 3 shows a metallic bag containing a curved ceramic armor tile in a conformal sheet metal container; and
FIG. 4 shows a metallic bag containing a flat ceramic armor tile in a conformal sheet metal container.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention is a method for metallic encapsulation of ceramic tiles to produce armor. A preferred embodiment of the method begins with selecting a ceramic tile of the desired geometry, which may include, for example, a flat plate or a torso plate. Examples of ceramic materials include, but are not limited to, silicon carbide, boron carbide, and alumina. The preferred embodiment here employs a silicon carbide tile.
The preferred embodiment then comprises the fabrication of a conformal sheet metal container, wherein suitable sheet or plate stock ranging from 0.005″ (0.0127 cm) to 0.250″ (0.635 cm) in thickness is made in the shape of the ceramic tile to be encapsulated. The sheet metal envelope can be formed by methods such as brake-forming, shearing, hydroforming, deep drawing, stamping or superplastic forming. The conformal sheet metal container is made with dimensions that are modestly oversized relative to the ceramic tile [+0.005″-0.010″ (0.0127-0.0254 cm)] so that the container fits comfortably around the ceramic tile, facilitating easy assembly. An example of a sheet metal container design 10 that allows for double encapsulation of individual hexagonally shaped ceramic tiles, as well as a three-tile array, is shown in FIG. 2 . This basic design can readily be adapted to different shapes such as rectangular or cylindrical tiles, as forming methods such as brake-forming, automated punching, stamping and spinning may be advantageously employed for fabrication of essentially an infinite variety of sheet metal container shapes. Additionally metallic encapsulation of even larger tile arrays can be done by replicating unit cells of containers that enclose multiple ceramic tiles.
Any suitable metal capable of being plastically formed using standard sheet metal forming techniques is a potential candidate for encapsulation of ceramic tiles to produce armor. Titanium, aluminum, and magnesium alloys have all been successfully employed, and it is obvious to those trained in the art that other metals, such as niobium, tantalum, copper, chromium, nickel, steel and zirconium, would also work well. The preferred embodiment here employs a titanium sheet metal container.
The ceramic tile is then placed in the sheet metal container with a suitable interlayer material. The interlayer material “wets” both the metal of the sheet metal container, in the preferred embodiment titanium, and the ceramic of the ceramic tile, in the preferred embodiment silicon carbide. By wetting, it is meant that a molten drop of the interlayer material on the metal or ceramic shows a sessile drop angle of less than ninety degrees. This means the droplet is spreading, probably chemically interacting with the metal and the ceramic, and flowing into narrow spaces well.
The interlayer material can be applied to the metal or ceramic as a paste or putty, if available in that form. Alternatively, some interlayer materials, such as aluminum 4047 alloy, are available in the form of foil. In the preferred embodiment, in which aluminum 4047 alloy foil is used, the entire package can be assembled like a sandwich with the sheets of interlayer material foil in between the metal and the ceramic. The conformal sheet metal container is then closed, typically with a full-lap or half-lap joint applied on the ninety degree portions of the bend, as seen in FIG. 2 . Such a fabrication approach provides for full encapsulation of the ceramic tile edges and good lateral confinement of the ceramic tile during impact. Edges are also protected against accidental impact using this container design. For initial fit-up purposes, tack welds using TIG or MIG methods are typically employed at all open corner seams although this is not an absolute necessity for the encapsulation to function successfully. The sheet metal container is then tack-welded to initial closure.
The conformal sheet metal container is then placed in a metallic bag that is seam welded and then evacuated. The metallic bag may be made out of a number of materials. It needs to have a high enough melting point to survive the bonding cycle (typically the melting point of the interlayer material); it needs to be amenable to vacuum-tight seam welding; and it needs to have adequate ductility to survive furnace processing. Examples of suitable metallic bag materials include, but are not limited to, mild steel and stainless steel. The preferred embodiment here employs a stainless steel metallic bag.
FIG. 3 shows a curved conformal sheet metal container 10 holding a curved ceramic tile, and FIG. 4 shows a flat conformal sheet metal container holding a flat tile, each in a separate, individually vacuum sealed, metallic bag 11 , 21 , respectively. In the preferred embodiment, the silicon carbide ceramic tile and the 4047 alloy interlayer material are placed in the Ti conformal sheet metal container, which is then put in a 0.002″ stainless steel metallic bag that is seam welded on three sides. The metallic bag is pumped out to remove all the air and moisture and then sealed when it is properly evacuated. The sealed metallic bag can then go into a brazing furnace (which effectively provides 15 psi of overpressure since the outside of the bag is at ambient pressure and the inside is under vacuum), or, alternatively, in a suitably equipped autoclave so as to provide a few hundred psi of overpressure outside the bag. The metallic bag is typically held just above the melting point of the interlayer material. For a material such as aluminum 4047 alloy, which has a eutectic melting composition of about 577 C, a preferred embodiment customarily bonds at temperatures of about 600 C. Anywhere from about 15-20 C above the interlayer melting point is typical. When the interlayer material melts, it flows and bonds the ceramic tile and the sheet metal together.
The mechanism of interlayer material bonding to the metal and the ceramic is via formation of intermetallic or intermediate phases that chemically bond the interlayer material to the ceramic and the metal. In the case of the aluminum 4047 alloy (which is 88% aluminum and 12% silicon) of the preferred embodiment, on silicon carbide, one would expect some mullite (SiO2:Al2O3), some Al4C3 and possibly some free Si. On titanium, one would expect phases like TiAl, Al3Ti, TiSi2, etc. which will form during the brazing process. This will also promote bonding, which needs some chemical interdiffusion of the interlayer material and both the ceramic and the metal portions of the laminate. However, it is important to avoid an excessive amount of intermetallic phase since many of these are brittle. It is necessary to establish custom bonding cycles for each specific materials combination.
The advantage of the metallic bag method of the present invention relates to simplicity and cost reduction. It also lends itself to automation and large volume production.
While the principles of the invention have been described herein, it is to be understood by those skilled in the art that this description is made only by way of example and not as a limitation as to the scope of the invention. Other embodiments are contemplated within the scope of the present invention in addition to the exemplary embodiments shown and described herein. Modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present invention.
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A method for the manufacture of metallically encapsulated ceramic armor through the use of low pressure processing methods in autoclave furnaces or brazing furnaces.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to magnetic resonance (MR) imaging, and more particularly relates to a method and apparatus useful for improving the quality of high resolution MR images that are sensitized to molecular diffusion.
[0003] 2. Description of the Prior Art
[0004] It is well known that magnetic resonance images can be degraded by motion during the imaging scan. Bulk motion of the object to be imaged is a particular problem for MR imaging methods that are designed to detect small diffusional motions of molecules within the object. These “diffusion-weighted” images are of interest, for example, for the detection of brain lesions associated with stroke. The MR apparatus (“imager”) allows diffusion sensitization in various spatial directions, and further analysis of images made sensitive in different spatial directions yields “diffusion tensor” images or maps, which provide information about the location and direction of nerve tracts (Basser et al., U.S. Pat. No. 5,539,310). A variety of pads and clamps are used to reduce patient motion during such examinations. The effects of motion are further reduced by employing rapid “single-shot” MR methods that acquire a complete image in approximately one-tenth of a second, such as Echo Planar Imaging (“EPI”), “spiral imaging” or “projection reconstruction” (“PR”). The invention will be described using the EPI method, with the understanding that spiral, PR, or other rapid methods may be employed in an analogous fashion. In spite of these efforts to minimize bulk motion, diffusion-sensitive images are often marred by significant artifactual signal loss in portions of the field of view, and some of this signal loss is associated with mechanical vibration of the patient (Maier et al., U.S. Pat. No. 7,239,140). Magnetic resonance imagers apply time-dependent pulses of electrical current to magnetic field gradient coils during the usual scanning process. Because these current pulses occur within the static magnetic field of the apparatus, they create unwanted mechanical vibrations that are transmitted to various components of the apparatus. In particular, these vibrations may be transmitted to the patient table, and cause vibration of the patient.
[0005] In general, the large and heavy MR apparatus does not attain a stable vibration pattern instantaneously, or even during the time required for one or a small number of EPI scans. Thus, it is possible to obtain one or a small number of images free of vibrational artifacts, provided that the apparatus is vibration-free at the start of the measurement period.
[0006] The complex vibrational motions of the MR apparatus are not determined solely by the physical characteristics of said apparatus. Said motions are strongly influenced by the strength, duration, and timing of the electrical pulses (the “gradient pulses”) applied to the magnetic field gradient coils (the “gradient coils”), and by which of the (typically three) gradient coils is energized or are simultaneously energized. Thus, the characteristics of the MR “pulse sequence” used to obtain the MR image strongly affect the mechanical vibration. MR pulse sequences designed to detect molecular diffusion are especially sensitive to mechanical vibration of the patient for two reasons. First, said sequences incorporate gradient pulses that deliberately sensitize the resulting images to motion, macroscopic or microscopic. Second, said gradient pulses are deliberately of high amplitude to make the resulting images as sensitive as possible to motion. The high current amplitude gives rise to a high gradient field and a strong mechanical force (a jolt) that may cause vibration of the apparatus. Thus, diffusion sensitive pulse sequences can both create unwanted vibration and can be very sensitive to the effects of said vibration.
[0007] For the purpose of this description, it is useful to distinguish radiofrequency (RF) “excitation” pulses from “echo-forming” RF pulses. By convention, the equilibrium magnetization, which aligns parallel to the main magnetic field, is said to point in the +z direction. The purpose of an RF excitation pulse is to nutate magnetization from the z (“longitudinal”) direction fully or partially into the x-y (“transverse”) plane, where it precesses and gives rise to a detectable signal. To obtain the strongest signal, the RF excitation pulse can nutate the z magnetization by 90°, but other nutation angles are also used. In contrast, the purpose of an echo-forming RF pulse is to flip the x-y magnetization, that is, to rotate the x-y magnetization, usually by 180°, about some axis which lies in the x-y plane and passes through the origin. This gives rise to the spin echo, which is generally useful in the construction of pulse sequences. FIG. 1 illustrates a single-shot pulse sequence that acquires all of the data required to reconstruct at least one image following the application of a single RF excitation pulse 40 . The five traces show the temporal relationships among the RF and gradient events, plotting relative amplitudes against time. The slice selection, readout, and phase-encoding gradients are applied along mutually orthogonal axes, for example the X, Y, and Z axes of the apparatus, while the diffusion-encoding gradient may be applied along any desired axis. Data are acquired during the oscillations of the readout gradient, only a few of which are shown. Spin echo data acquisition schemes require one (e.g., 52 in FIG. 2 ) or more echo-forming RF pulses, but these do not rotate additional magnetization from the z axis into the x-y plane, and do not change the single-shot nature of the pulse sequence. In contrast, multi-shot pulse sequences require two or more RF excitation pulses to acquire all the data require to reconstruct an image, and, to avoid image artifacts, precautions must be taken to ensure the consistency of the several partial data sets needed to reconstruct an image.
[0008] To acquire the data needed to reconstruct the image of a single slice, typical diffusion sensitive sequences sequentially apply two or more high amplitude gradient pulses (a “multiplet”) to sensitize (“encode”) the resulting images to diffusional motion in one particular spatial direction. Although many encoding schemes are possible, the effect of these pulses will be illustrated in a non-limiting manner by their simplest forms. The ordinary slice-selective RF excitation pulse 40 of the single-shot EPI pulse sequence is followed by a first diffusion-encoding gradient pulse of positive amplitude ( 41 in FIG. 1 ), and thereafter by a second diffusion-encoding gradient pulse of equivalent duration, but negative amplitude ( 43 ). Said first diffusion-encoding pulse changes the phases of (“dephases”) the nuclear magnets (“spins”) along one spatial direction. For stationary spins, said second diffusion-encoding pulse, which has the same spatial orientation as the first diffusion-encoding gradient pulse, but the opposite polarity, reverses (“rephrases”) the phase changes induced by the first diffusion-encoding gradient pulse. More generally, the rephasing of stationary spins occurs when the integral over both pulses is zero. Spins that have moved by diffusion or bulk motion in the selected direction during the time between the two pulses remain somewhat dephased, and the MR signal from these spins is reduced. This sensitivity to diffusion is enhanced by the use of stronger or longer diffusion-encoding gradient pulses, or by increasing the time between the dephasing and the rephasing gradient pulses. The diffusion-encoding period is followed by an EPI readout and phase encoding scheme of ordinary design ( 44 ) that acquires, for single-shot scans, all the data needed to form one two-dimensional image at one slice position in approximately 0.1 second. EPI is often performed using an echo-forming RF pulse to form a spin echo. In this case, it is efficient to apply the first diffusion-encoding gradient pulse 51 before the echo-forming RF pulse 52 , and to place the second diffusion-encoding gradient pulse 53 after said RF pulse (E. O. Stejskal, and J. E. Tanner, J. Chem. Phys. 42 (1965) 288). The echo-forming RF pulse reverses the sense of the dephasing created by the first diffusion-encoding gradient, so the second diffusion-encoding gradient pulse is applied with the same polarity as the first diffusion-encoding gradient pulse, and both pulses have the same integral.
[0009] For example, to sensitize the resulting image to motion in the X spatial direction, said diffusion-encoding pulses are applied to the conventional X gradient coil. To sensitize the image to motion in a direction that is not aligned with the usual X, Y, or Z axes, simultaneous current pulses with appropriate amplitudes are applied to an appropriate combination of two or three of the conventional X, Y, and Z gradient coils. These diffusion-encoding gradient pulses are typically the strongest, or are among the strongest, gradient pulses of the pulse sequence, and will make a significant contribution to any vibration of the apparatus. To determine the spatial orientation of the diffusional motion, it is common practice to acquire additional images at the same slice position utilizing diffusion-encoding gradient pulses that sensitize said images to motion in additional distinct spatial directions. Since the spatial orientation of the gradients used for diffusion sensitization of said images is unrelated to the gradient directions used for ordinary slice selection, readout, and phase encoding, a plurality of images at the same slice position, but having different orientations of diffusion sensitization, may be acquired in separate single-shot scans, altering only the diffusion-encoding gradients. To detect and quantify the diffusion-induced reduction in signal intensity, it is common to acquire as reference an additional image at said slice position in the absence of the diffusion-encoding pulses. To obtain additional information about the diffusion process, it is also common to acquire additional images at said slice position with diffusion encoding along said distinct spatial directions, but having different sensitivities to the diffusion process (the so-called “b values”). For example, the diffusion sensitivity of the pulse sequence in FIG. 1 may be altered by changing the magnitude of gradient pulses 41 and 43 in multiplet 45 by the same factor, or by changing their durations appropriately. Each of the changes to the diffusion-encoding pulses described above is intended to produce a different image that reveals additional distinct information about the diffusing nuclear spins, and the altered diffusion parameters will be termed “distinct diffusion-encoding orientation and sensitivity combinations,” to distinguish said changes from alterations in the diffusion-encoding pulses, described below, that are deliberately designed to provide a plurality of distinct gradient pulse multiplets that maintain the same diffusion-encoding orientation and sensitivity, creating a plurality of pulse sequences that yield essentially equivalent images. These altered but equivalent pulse shapes will be termed “equivalent diffusion-encoding gradient pulse multiplets.” Having specified the desired distinct diffusion-encoding orientation and sensitivity combinations, it is clinically advantageous to acquire images at a plurality of different slice positions with each said encoding, as well as unencoded reference images at each of these slice positions. A typical diffusion-sensitized acquisition may thus generate images at a plurality of parallel slice positions, images at each of said slice positions being acquired with a plurality of diffusion-encoding directions (orientations), with a plurality of diffusion-encoding sensitivities for each of said directions, and a reference image without diffusion encoding for each slice position. Because changing the spatial direction of the diffusion-encoding is accomplished by changing the currents in two or more of the typical X, Y, and Z gradient coils, it is expected that the apparatus will experience mechanical jolts with different characteristics for each distinct diffusion-encoding orientation. It is clear that changing the diffusion sensitivity by changing the amplitude of diffusion-encoding gradient pulses will increase or decrease the associated mechanical jolts. In contrast, it is the usual practice to change from one slice position to a different parallel slice position by changing the frequency of the RF pulse or pulses, which does not alter the mechanical forces experienced by the apparatus.
[0010] Because the RF pulses that excite the nuclear spins in a specified slice of tissue have essentially no effect on the nuclear spins of a second, parallel, non-overlapping slice, “single shot” methods such as EPI can acquire a plurality of non-overlapping slices very rapidly, one right after another. However, for many medical applications, including diffusion-sensitized imaging, it is not advantageous to acquire multiple images at a single particular slice position in rapid succession, because the slice-selective RF excitation pulse (40 or 50) transiently reduces the z magnetization within the slice, diminishing the z magnetization available for the next RF excitation pulse, and thus, in succeeding images, reducing the x-y magnetization that gives rise to detectable signal. It is advantageous to allow a consistent waiting period for the nuclear spins within a particular slice of tissue to relax partially or fully back to their equilibrium magnetization before disturbing said spins with another RF excitation pulse. For single-shot imaging, all of the data for one image are acquired following a single RF excitation pulse, so failure to maintain a consistent time (TR) between the RF excitation pulses that acquire separate images at one particular slice position does not result in significant image artifacts (e.g., ghosts), but rather in undesirable variations in brightness and contrast from image to image. Such brightness differences make it difficult to evaluate the effects of diffusion. It is efficient to image a plurality of other essentially non-overlapping slice positions while waiting for the magnetization of the spins at the first slice position to relax. These considerations lead to the usual, orderly sequence of events in a single-shot diffusion-sensitive pulse sequence: all of the data are acquired for one image at a first particular slice position utilizing a first particular “distinct diffusion-encoding orientation and sensitivity combination” [vide supra], then all of the data are acquired for a second particular, non-overlapping slice position with said first particular distinct diffusion-encoding orientation and sensitivity combination, this process being repeated until data have been acquired from all desired slice positions. Thereafter, data are acquired again from the first particular slice position utilizing a second particular distinct diffusion-encoding orientation and sensitivity combination, this combination having a spatial orientation or diffusion sensitivity that differs from said first particular distinct combination. Data are then collected from the remaining slice positions in the same slice order utilizing said second particular distinct diffusion-encoding orientation and sensitivity combination. Following this pattern, data are collected for each slice position using each of the desired diffusion-encoding sensitivities or directions. In the simplest implementation of this pulse sequence, no changes are made to the timing of the diffusion-encoding pulses: the diffusion sensitivity is adjusted by gradient amplitude changes, and the orientation of the encoding is changed by a redistribution of the currents in the X, Y, and Z gradient coils without altering the vector sum gradient strength. The regular, repetitive acquisition of a “block” of distinct slice positions in a fixed spatial-temporal order ensures the desired, constant TR for all of the images, as long as the conventional pre-scans have been performed to establish a steady state of the magnetization. An advantage of this data collection scheme is that its nested, repetitive structure is easily programmed using the looping statements available in all computer languages. An example of such a scheme is shown in FIG. 3 for five distinct parallel slices at positions S 1 -S 5 , four diffusion-encoding directions D 1 -D 4 , two nonzero diffusion-encoding sensitivities (amplitudes) A 1 -A 2 , and a set of five unencoded (zero diffusion-encoding amplitude, denoted A 0 ) slices. Each of the 45 boxes, numbered in temporal order, represents one complete single-shot image acquired with a unique combination of parameters. The time between each acquisition is constant. Each block of five slices is encoded with the same diffusion weighting, for example D 1 -A 1 for images # 01 to # 05 , resulting in a completely repetitive gradient pulse pattern. In this example, the unencoded slices are acquired last (image # 41 to image # 45 ). The mechanical jolting of the MR apparatus occurs as each image is acquired, typically about every 0.1 second. This period will be called the Mechanical Repetition Time or MRT to distinguish it from TR, the time between the acquisition of a single-shot image at a particular slice position and the next acquisition at the same slice position. For example, if the images in FIG. 3 are acquired, one after another, every 0 . 1 second, then slice S 1 is acquired with a new combination of diffusion-encoding orientation and sensitivity every 0.5 second. The MRT is 0.1 second, and the TR is 0.5 second.
[0011] The mechanical jolting of the MR apparatus is a highly regular process. It is the usual practice that the single-shot acquisitions required for a plurality of slices be distributed evenly in time over the selected TR period, resulting in a steady beat of the diffusion-sensitizing gradient pulses, and a constant value of the MRT. Furthermore, the gradient pulses used to select one particular slice position do not differ from the gradient pulses used to select other parallel slice positions, so the mechanical jolts applied to the MR apparatus for each of the example five slices will be the same for the first particular distinct diffusion-encoding orientation and sensitivity combination (images # 01 to # 05 ). When this same five-slice block is again imaged with the second particular distinct diffusion-encoding orientation and sensitivity combination (images # 06 to # 10 ), the resulting mechanical jolts will have a different amplitude or direction from the jolts resulting from the first particular distinct diffusion-encoding orientation and sensitivity combination, but will maintain the same MRT.
[0012] The vibration induced in the patient is a function of the mechanical design of the MR apparatus and the amplitude, timing, and phase of the mechanical jolts created by energizing the gradient coils. The operator of the MR imager has some control over said amplitude and timing. For example, the operator may increase the TR, and thus for common sequences the MRT, to avoid an MRT period that creates a strong mechanical resonance within the MR imager and substantial image artifacts. In practice, however, there is no value of the MRT which completely eliminates mechanical vibration. Existing MR pulse sequences that acquire data in the order described by the example above usually have a sufficient number of slices, and thus a sufficient number of identical and equally-spaced mechanical jolts, to establish an undesired steady state of rhythmic motion in the patient table of the MR imager, and thus in the patient.
[0013] For multi-shot diffusion-weighted imaging, an RF excitation pulse is followed by diffusion-encoding gradient pulses, and then the collection of only part of the data required to reconstruct an image. This partial data acquisition (shot) must be repeated several times to acquire all of the data needed for an image, and the diffusion encoding must be effectively the same for each shot. Thus, when standard pulsing schemes are applied to multi-shot, multi-slice diffusion-weighted imaging, long trains of identical diffusion-encoding pulse multiplets may result. Maier et al. (U.S. Pat. No. 7,239,140) recognized that it is possible to create a plurality of diffusion-encoding gradient pulse multiplets of the same spatial orientation and diffusion sensitivity, but different mechanical properties. For example, the gradient amplitudes of pulses 51 and 53 of multiplet 55 in FIG. 2 can be negated, reversing the current flow in the associated gradient coil or coils. This reversal of polarity does not alter the spatial orientation of the diffusion encoding or the diffusion sensitivity (b value), but one may expect that the mechanical properties of the jolt resulting from such a modified pulse will differ from that of the original multiplet 55 . Other possible modifications include, for example, increasing the gradient pulse duration while decreasing the amplitude, or using four encoding pulses per multiplet instead of the two shown in FIG. 2 , all while maintaining the same encoding orientation and sensitivity. These modifications create pulses that are “equivalent diffusion-encoding gradient pulse multiplets” with respect to randomly diffusing spins, but not equivalent with respect to the vibrations they induce. In the absence of net motion along the encoding direction, and gradient imperfections such as eddy currents, these equivalent multiplets may be used as substitutes for some of the original multiplets without affecting the final images. The desired diffusion-weighted pulse sequence may then be played out in the usual order of slice positions and diffusion encoding orientations and sensitivities, substituting equivalent diffusion-encoding gradient pulse multiplets for an optimized or random subset of the original diffusion-encoding gradient pulse multiplets, thus altering the vibrational character of the sequence. This partial substitution may be optimized by computer simulation and monitored by a vibration sensor 32 attached to the patient table. The method is applicable to single-shot imaging. FIG. 4 shows an example of such a partial multiplet substitution applied to the same order of slices, encoding orientations and encoding sensitivities used for the single-shot example of FIG. 3 . A plus sign in front of the diffusion direction indicates the same pulse multiplet used in FIG. 3 , while a minus sign indicates a reversal of the gradient currents, that is, a negation of the amplitude of each gradient pulse used to create the diffusion-encoding multiplets like 45 in FIG. 1 . The fully repetitive pattern of gradient pulses seen, for example, from image # 01 to image # 05 in FIG. 3 , is broken up by irregular diffusion-encoding gradient reversals in FIG. 4 . In the absence of bulk motion or gradient eddy current effects, the 45 images that result from the encoding gradients in FIG. 4 should be equivalent to those obtained from the repetitive pulse sequence in FIG. 3 . The MRT has not changed, but the nature (e.g., direction) of some of the mechanical jolts will have changed, thus altering the vibrational characteristics of the apparatus.
SUMMARY OF THE INVENTION
[0014] A method and apparatus for diffusion-sensitive magnetic resonance (MR) imaging of a living patient, wherein undesired image artifacts induced by the rhythmic motion of the patient table are reduced by advantageously manipulating the order of the diffusion-encoding gradient pulses and the timing of slice acquisitions in a manner that interrupts, diminishes, or cancels said rhythmic motion. In contrast to existing pulse sequences that begin by acquiring one image at each of a plurality of different parallel slice positions, one after another, with diffusion-encoding gradient pulses having a first fixed combination of one diffusion-encoding orientation and one sensitivity and repetitive timing, a first aspect of the invention acquires one image at each of a plurality of different slice positions, one after another, utilizing a first varying combination of diffusion-encoding orientations and sensitivities that is chosen to avoid a rhythmic pattern of the gradient pulses in the X, Y, and Z gradient coils. After acquiring one image at each of the desired slice positions in the slice block, the slices are reacquired repeatedly in the same positional order using additional distinct varying combinations of diffusion-encoding orientations and sensitivities, until one image has been acquired with each desired, unique combination of the slice position, the diffusion-encoding orientation, and the diffusion-encoding sensitivity, that is, for each “encoding/slice combination.” This slice by slice and block by block scrambling (reordering) of the orientations and sensitivities advantageously includes the reference images, one for each desired slice position, which are thus scattered among the diffusion-sensitized acquisitions. An irregular pattern of these reference images, which lack high amplitude diffusion-encoding gradient pulses, is helpful for disrupting regular patterns of mechanical jolts. Thus, the invention reduces vibration by a random or optimized reordering of a minimal set of diffusion-encoding gradient pulse multiplets having the desired combinations of diffusion-encoding orientations and sensitivities, compared to existing methods which modify a first set of encoding pulse multiplets to create a set of equivalent diffusion-encoding gradient pulse multiplets having the same diffusion-encoding orientation and sensitivity as said first set, and then apply a pattern of unmodified and the modified pulse multiplets to different slices as in the example of FIG. 4 . The invention provides a straightforward method of decreasing the repetitive nature of succeeding diffusion-encoding pulse multiplets without changing the duration, amplitude or multiplicity of the pulse multiplet associated with a given diffusion-encoding orientation and sensitivity.
[0015] Since the invention does not adhere to a repeated pattern (a “nested loop structure”) of diffusion-encoding orientations and sensitivities, additional images with any desired diffusion encoding, or with no encoding, may be acquired without restriction to such a structure. In a second aspect of the invention, additional unencoded images, beyond the one reference image commonly acquired at each distinct slice position, are scattered throughout the entirety of the scan to further interrupt the rhythmic pattern of mechanical jolts.
[0016] A third aspect of the invention uses irregular timing between the slices within a slice block to suppress regular jolting of the apparatus and thus vibration. Because each slice position will eventually be acquired with a plurality of distinct combinations of diffusion-encoding orientation and sensitivity, it is necessary to maintain a constant repetition time for the spins at each slice position, so the slice position order and the irregular timing within the slice block remain unchanged as the block is repeatedly imaged with different varying combinations of diffusion-encoding orientations and sensitivities.
[0017] Either the first aspect of the invention or the third aspect of the invention may be used independently to reduce undesired vibration, or both aspects of the invention may be used simultaneously and advantageously to reduce the vibration further. If the first aspect of the invention is utilized, then the second aspect of the invention may be employed to reduce vibration further. Because the optimal reordering pattern of the diffusion-encoding gradients and the optimal alteration of the slice-to-slice timing will change from patient to patient, the invention provides the operator with means to adjust said pattern and said timing. To guide manual changes of this adjustment or to permit automatic adjustment, the invention optionally provides means to measure and quantify the vibration of the patient table using known methods.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 illustrates the time course of the initial portion of a gradient-echo diffusion-weighted echo planar MR pulse sequence of known design.
[0019] FIG. 2 illustrates the initial portion of a spin-echo diffusion-weighted echo planar MR pulse sequence of known design wherein all data required for one image are acquired after the application of two RF pulses.
[0020] FIG. 3 shows an example of the temporal sequence of diffusion-encoding events for an acquisition of ordinary design.
[0021] FIG. 4 shows an example of the temporal sequence of diffusion-encoding events for an acquisition following a pattern described in U.S. Pat. No. 7,239,140.
[0022] FIG. 5 illustrates an MR imaging system useful for carrying out the method and apparatus of the invention.
[0023] FIG. 6 shows an example of the temporal sequence of diffusion-encoding events for an acquisition according to the first aspect of the invention.
[0024] FIG. 7A shows a portion of the acquisition timing for five representative slices in a diffusion-encoding sequence of conventional design.
[0025] FIG. 7B shows an example of the irregular pulse timing of the same slices and diffusion directions in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] FIG. 5 shows a block diagram illustrating the operation of an MR imaging system 10 which may be used in connection with the method and apparatus of the invention. Since such imagers are well known, what follows is only a brief overview description of such a device. In the interest of brevity and clarity, throughout the remaining description only specific changes from known and conventional parameters are provided, in order to give the reader a complete understanding of the invention without undue complexity.
[0027] A magnet 12 is provided for creating a static/base magnetic field in a body 11 positioned on a table 13 to be imaged. Within the magnet system are gradient coils 14 for producing position dependent magnetic field gradients superimposed on the static magnetic field. Gradient coils 14 , in response to gradient signals supplied thereto by a gradient module 16 , produce the position-dependent magnetic field gradients in three orthogonal directions. Within the gradient coils is an RF coil 18 . An RF module 20 provides RF pulse signals to the RF coil 18 , which in response produces magnetic field pulses which rotate the spins of the protons in the imaged body 11 by ninety degrees or by one hundred and eighty degrees or by a different angle useful for the particular imaging technique. In response to the applied RF pulse signals, the RF coil 18 receives MR signals, i.e., signals from the excited protons within the body as they return to an equilibrium position established by the static and gradient magnetic fields, which MR signals are detected by a detector 22 (comprising a preamplifier and amplifier). The MR signals are then filtered by an analog low-pass filter 23 , converted into digital signals by a digitizer 24 and applied to the MR systems computer 26 . Alternatively, the function of analog low-pass filter 23 may be carried out by subjecting the digital signals supplied from digitizer 24 to digital filtration algorithms in computer 26 . In a manner well known to those of ordinary skill in this technology, the gradient magnetic fields are utilized in combination with the RF pulses to encode spatial information into the MR signals emanating from a plurality of slices of the body being imaged. A computer 26 , knowing the details of the applied gradient magnetic fields, processes the detected MR signals so as to generate images of a selected slab (or slabs) of the body, which are then shown on a display 28 . In one embodiment of the invention, a sensor 32 , of ordinary design, but selected to be insensitive to the static and time-varying magnetic fields of the MR apparatus, measures the vibration of the patient table, and supplies a signal to the computer 26 to evaluate the efficacy of the invention for reducing the vibration of the table. In the presence of the main magnetic field supplied by the magnet 12 , the current pulses supplied by the gradient module 16 to the X, Y, and Z gradient coils 14 create periodic mechanical jolts to said coils, and these vibrations are transmitted via various components of the system to the patient table 13 and thence to the patient 11 . Although it is difficult to predict the vibrational motion of the patient table, it is clear that higher amplitude current pulses in the gradient coils will give rise to stronger jolts, and that the mechanical characteristics of these jolts will differ for the X, Y, and Z coils, which have different winding geometries.
[0028] Comparison of repetitive images obtained with and without high amplitude diffusion-encoding gradient pulses shows that these pulses are responsible for significant image artifacts. Although changes in the multiplet structure of these pulses, such as between multiplet 45 and multiplet 55 , will clearly alter the mechanical characteristics of the jolts produced by the pulses, no fixed choice of multiplet design will eliminate vibration of the apparatus. Fortunately, one or a small number of artifact-free single-shot diffusion-weighted images may be acquired before vibrational image artifacts are observed; it is the regular repetition of identical jolts that establishes artifact-inducing vibration of the patient, rather than the effect of a single jolt or a small number of jolts. The purpose of the invention is to make irregular changes to the characteristics of the jolts or to disturb the regular rhythm of these jolts, or both, thus preventing the establishment of a rhythmic pattern of vibrations in the patient. For a single-shot diffusion-weighted acquisition of ordinary design, images are obtained at NS distinct slice positions S 1 through S NS , ND distinct diffusion-encoding orientations D 1 through D ND , and NA distinct diffusion-encoding sensitivities A 1 through A NA . The example of FIG. 3 shows the temporal order of the S, D, and A values for a sequence of said ordinary design where NS=5, ND=4, and NA=2, listing the values associated with each image in a separate numbered box. Additionally, an unencoded reference image (A 0 ) is acquired at each of the five slice positions. The number of distinct diffusion-encoding orientation and sensitivity combinations (“NC”) is therefore ND×NA+1, and each of the NC combinations is used for an image at each of the NS slice positions. Thus the total number of encoding/slice combinations (“NES”) is NS×ND×NA+NS. In the example of FIG. 3 , a total of 5×4×2+5=45 images are acquired during the complete scan. Each slice within each block of NS slices, for example each row in FIG. 3 , is acquired with the same values of D and A, that is, with exactly the same diffusion-encoding pulse multiplet. Since the time between slices is ordinarily held constant, and the slice positions are selected by the ordinary method of shifting the frequency of the slice-selective RF excitation pulse, rather than by changing gradient amplitudes, the exact same pattern of gradient pulses is repeated NS times, a condition likely to create vibration of the patient, especially for large values of NS.
[0029] In the looping structure of FIG. 3 , five slices are acquired with four different direction values using amplitude A 1 , and then the five slices are acquired again with four different direction values using amplitude A 2 . An alternative ordinary looping structure would acquire five slices with two different amplitude values using direction D 1 , and then these ten acquisitions are repeated with D 2 , and then D 3 and then D 4 . This alternative looping pattern has the same disadvantages as that shown in FIG. 3 , and will not be illustrated.
[0030] For single-shot imaging, there is, however, no compelling reason to acquire all of the desired slices within one slice block with only a single combination of diffusion-encoding orientation and sensitivity, for example the combination D 1 -A 1 in the first row of FIG. 3 . The first aspect of the invention recognizes that, subject to certain conditions, each of the NS slices in a given slice block may be diffusion-encoded with any of the NC distinct combinations of diffusion-encoding orientation and sensitivity. It further recognizes that an irregular temporal order of said combinations can be used to suppress vibration. In the first step of the method, an “Initial List” is prepared of the NES desired encoding/slice combinations. This Initial List ordinarily contains NS×ND×NA+NS elements, but may exclude certain unneeded combinations or include duplicates of certain combinations for which multiple images are desired. Then, NS elements are picked from the list, one associated with each of the slice positions S 1 , S 2 , S 3 , . . . S NS in the first slice block, and these combinations are placed in the desired slice order at the beginning of a temporally “Reordered List,” forming the first slice block. These combinations of D and A are selected to avoid a repeating pattern, to avoid a pattern known to cause unacceptable vibration, or to use a pattern known to suppress vibration. Then, a second set of NS elements is picked from the unused combinations of S, D, and A in the Initial List, one associated with each of the S NS slice positions, and these combinations are placed in the second slice block of the Reordered List in the same slice order as within the first slice block. Thereafter, additional combinations of S, D, and A are picked from the unused combinations in the Initial List and are transferred to the Reordered List, until the Reordered List contains all NES combinations. The order of the D and A values are selected as described above to avoid vibration, while the values of S have a fixed repeating order to maintain the same slice ordering within each block of NS slices in the Reordered List.
[0031] In accordance with the invention, the acquisition order of the 45 encoding/slice combinations in the example of FIG. 3 is reordered in one of many possible ways to give the non-limiting example of FIG. 6 . In the first slice block (row), a different combination of D and A values is used for each slice, including one slice that has no diffusion encoding, thus breaking the rhythm of the repetitive pattern in FIG. 3 . A properly selected variation in the values of D and A creates an irregular pattern of currents in the X, Y, and Z gradient coils, which in turn creates a series of mechanical jolts having varying characteristics, reducing the tendency to establish a rhythmic motion in the patient. Vibration is further suppressed by the judicious scattering of the NS reference images, with no diffusion-encoding gradients, in this Reordered List.
[0032] Since there is no correlation between the desired number of slices NS and the desired number of combinations of diffusion-encoding orientation and sensitivity NC, the block of slices in the Reordered List may contain more slice positions NS than said combinations NC, in which case the slice block will contain slices having different slice positions but sharing the same combination of diffusion-encoding orientation and sensitivity. In this case, and to the extent possible, the invention avoids acquiring temporally consecutive slices with the same combination of diffusion-encoding orientation and sensitivity. On the other hand, the desired number of slices NS might be less than NC, and some of the distinct desired combination of diffusion-encoding orientation and sensitivity will not be used within one particular slice block. If it is desired that certain encoding/slice combinations be deleted or added to the typical list of NS×ND×NA+NS elements, it may be necessary to add additional scans to maintain the fixed, repeating S 1 , S 2 , S 3 , . . . S NS slice order.
[0033] This first aspect of the invention disrupts the rhythmic jolting of the apparatus by scrambling the ordinary order of the desired D and A values, rather than creating equivalent diffusion-encoding gradient pulse multiplets, that is, modified pulse multiplets having the same diffusion characteristics but different mechanical characteristics, as described by Maier (U.S. Pat. No. 7,239,140).
[0034] A scattered arrangement of the unencoded reference images is particularly helpful for breaking the rhythmic pattern of the mechanical motion of the apparatus because these acquisitions lack the strong diffusion-encoding gradient pulses used for the diffusion-encoded images. The first aspect of the invention scrambles the diffusion encoding by avoiding the strict, nested-loop structure shown in FIG. 3 . This, in turn, allows additional images to be added to the Reordered List freely, subject only to the requirement that slices be excited in a strictly repeating order:
S 1 , S 2 , S 3 , . . . S NS , S 1 , S 2 , S 3 , . . . S NS , . . .
[0036] In a second aspect of the invention, the usual NS unencoded images are supplemented with the acquisition of an additional NS unencoded images, one for each slice position in the slice block. The temporal positions of these additional acquisitions are scattered throughout the acquisition of the entire set of NES images, either randomly or in a specific pattern that further minimizes vibration. This concept can be expanded by adding as many additional unencoded images as desired, NS at a time, dispersing them throughout the acquisition of the entire set of NES images, further disrupting the pattern of mechanical jolts at the cost of a modest increase in the total imaging time.
[0037] In single-shot pulse sequences of ordinary design, the time needed to acquire each single image is constant, and the most rapid multi-slice acquisition allows no waiting time between the acquisition of one slice and the next. This naturally leads to repetitive mechanical jolting. If TR is increased, some waiting time is added to the slice block, and this is ordinarily divided equally among the NS slices, again leading to repetitive mechanical jolting as shown for the five example slices in FIG. 7A . In this example, the time required for the acquisition of a slice is shown by the width of the rectangle, the waiting time is shown by the space between rectangles, the slice position is indicated by S, the diffusion encoding direction is indicated by D, and amplitudes are omitted. All of the values of the MRT are equal. TR is the time from the excitation of a particular slice to the next excitation of the same slice, and all of the TR values are the same, a requirement for consistent image intensity. For this example, TR is five times the value of the MRT. In a third aspect of the invention, diffusion-encoding gradient pulses are applied in the order used by existing pulse sequences, but the ordinarily consistent period between the acquisitions of the slices is made inconsistent to disrupt the rhythmic jolting of the apparatus. FIG. 7B shows that it is possible to create unequal values of the MRT between slice acquisitions while still retaining the required consistency of TR for each slice. This requires the operator to select a value of TR larger than the minimal value. The invention divides this additional time into NS unequal portions in a fashion chosen to break the rhythm of the mechanical jolts. Inserting said time portions between the slice acquisitions yields NS mutually unequal values of the mechanical repetition time, for example, MRT 1 through MRT 5 in FIG. 7B . To maintain a constant value of TR for each slice, the same unequal MRT values in the same order must be repeated each time the block of NS slices is imaged with various values of the diffusion-encoding directions and amplitudes. Thus the mechanical jolts from the diffusion-encoding and other gradient pulses occur at unequal intervals, while the RF excitation of a particular slice location occurs repeatedly at intervals of TR. FIG. 7B shows a pseudo-random pattern of waiting times between slice acquisitions, but a monotonic increase or decrease of the MRT values over the slice block will also disrupt the rhythm of the jolts. Although the pattern of MRT values repeats each time the block of slices is imaged, this repetition typically occurs at a frequency lower than the important mechanical resonances of the MR imager.
[0038] In a fourth aspect of the invention, the reordering of the diffusion-encoding parameters A and D described in the first aspect of the invention is combined with the timing changes described in the third aspect of the invention to further reduce the vibration of the apparatus. Additional unencoded images may be acquired as described in the second aspect of the invention.
[0039] It is recognized that no combination of gradient amplitude rearrangements or timing changes will eliminate vibration of the patient table. It is the purpose of the invention to prevent the MR apparatus from attaining a vibrational steady state with high motion amplitudes. Rather than seeking an optimal reordering and timing pattern from the large number of possibilities, the invention assumes that a few selected non-rhythmic patterns will in most cases create less image artifact than the strongly rhythmic pattern of existing sequences. Because the complex vibrations of the patient table will change from one patient to the next, and from one set of sequence parameters, such as TR and the number of slices, to the next, the invention allows the operator to select from a small menu of gradient and timing patterns. These patterns may be estimated or computed, and are accepted or rejected on the basis of the vibration amplitude or image artifact in a short test measurement.
[0040] The starting point for selecting a suitable gradient reordering scheme is a fixed, repeating set of slice positions combined with a pseudorandom rearrangement of the desired combinations of diffusion-encoding orientation and sensitivity, as in FIG. 6 . The algorithm then scans the list for temporally adjacent slices having the same values of D and A, and further rearranges the list to avoid this adjacency. Suitable timing patterns for the third aspect of the invention are similarly created from a pseudorandom pattern, rearranged to avoid having close MRT values for temporally adjacent slices. Other timing patterns are chosen to change the MRT values smoothly from, for example, a minimal value to a larger value, sweeping rapidly through any MRT value that might, if repeated, reinforce a mechanical resonance of the system. After the operator selects a diffusion encoding reordering scheme, or a scheme for varying the MRT values, or both, a short test acquisition is performed to confirm the suitability of the choice. The results of this test may be evaluated by manual review of the images, or, for images at the same slice position, by a computerized comparison of the nominally equivalent images. If the images show vibration artifact, the operator may choose a different set of reordering or timing patterns. A more automated embodiment of the invention employs a vibration sensor of ordinary design, but compatible with the static and time-varying magnetic fields of the MR imager, attached to the patient table. The amplitude of the sensor signal as the preliminary scans are performed gives immediate feedback to the scanner, and the most suitable of the preliminary scan patterns can be selected by straightforward computer algorithms without operator intervention.
[0041] Thus, a method for producing an image of an object located in the field of view of an MR imaging system, which image is sensitized to molecular diffusional motions within the object, includes the following steps.
[0042] (a) selecting combinations of diffusion-encoding gradient pulses of suitable amplitudes and orientations to sensitize the pulse sequence to diffusional motion in the desired directions;
[0043] (b) selecting the number of slices (“NS”) to be acquired and their distinct spatial positions;
[0044] (c) creating one or more lists of the amplitudes and directions of the pulses in (a) and the slices in (b), making entries for each desired combination of slice position, diffusion-encoding direction, and diffusion-encoding amplitude, usually including an amplitude of zero for reference at each slice position, such that pulses of similar amplitude and direction are not adjacent, and selecting one of these lists for use;
[0045] (d) selecting the repetition time TR, and subtracting from this the minimum possible TR to compute the extra waiting time between the slice acquisitions;
[0046] (e) dividing the extra waiting time, if any, into NS unequal portions, and creating a list of these time portions;
[0047] (f) acquiring a rapid image at the first slice position, using the first combination of diffusion-sensitizing pulses from the list chosen in (c);
[0048] (g) waiting for a period of time determined by the first time value in the list (e);
[0049] (h) acquiring a rapid image at the next slice position, which does not overlap the first slice position, using the next combination of diffusion-encoding pulses from the list chosen in (c);
[0050] (i) waiting for a period of time determined by the next time value in the list (e);
[0051] (j) repeating steps (h) and (i) until one image has been acquired from each desired slice position;
[0052] (k) again acquiring a rapid image at the first slice position, using the next combination of diffusion-sensitizing pulses from the pulse list chosen in (c);
[0053] (l) waiting for a period of time determined by the first time value in the list (e);
[0054] (m) acquiring a rapid image at the next slice position, using the next combination of diffusion-encoding pulses from the list chosen in (c);
[0055] (n) waiting for a period of time determined by the next time value in the list (e);
[0056] (o) repeating steps (m) and (n), reacquiring slices in the same order as in (j), and using waiting periods after each acquisition from list (e), until all desired diffusion-sensitizing pulses from the list chosen in (c) have been used for every slice position selected in (b);
[0057] (p) evaluating either the vibration level of the patient table with a sensor, or evaluating the images manually or automatically for artifact;
[0058] (q) repeating steps (f) through (p), using a different one of the pulse lists created in step (c), and optionally a new uneven division of the waiting time (e), until satisfactory results are obtained.
[0059] Although the best estimation of the efficacy of the pulse reordering and timing disruption is made with full scans of every desired slice and every desired diffusion encoding, reasonable preliminary scans may be performed more rapidly by reducing the number of slices or the number of diffusion encodings. After examining the preliminary scans for artifacts, or after measuring the patient table vibration, a final imaging scan is performed with the full number of slices and diffusion encodings.
[0060] In a further embodiment of the invention, the operator may choose among the primary and secondary lists of gradient pulses (for the first embodiment) or among the primary and secondary timing lists (for the second embodiment), or both (for the third embodiment). The operator can acquire a full or partial scan to evaluate the vibration artifact manually, and select the best list or lists. If a partial scan was used to evaluate the vibration artifact, a final scan can be run with the preferred lists.
[0061] Although modifications and changes may be suggested by those skilled in the art, it is the intention of the inventors to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of their contribution to the art.
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In a method and apparatus for magnetic resonance (MR) imaging of an object, and in particular MR imaging that yields images sensitive to molecular diffusion, undesired image artifacts induced by the rhythmic motion of the apparatus are reduced by manipulating the amplitude, phase, and timing of the diffusion encoding gradient pulses in a manner that interrupts, diminishes, or cancels the rhythmic motion. The residual vibration is evaluated manually or automatically to make such manipulations.
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This invention is a combined load power consumption reduction system, voltage stabilizing control system, and power supply system, particularly for controlling the power supplied to street-lighting loads (luminaires) and especially for high-intensity discharge (HID) and fluorescent luminaires.
BACKGROUND OF THE INVENTION
Street lighting systems may be operated by manually operated switches, but more frequently they are operated under the control of a photoelectric cell or timer or a programmed combination of both a timer and a photoelectric cell. In conventional such systems, steady-state power is applied to the load at full rated voltage.
Experience shows that street lights may operate at power levels substantially below rated power levels without causing a perceptible decline in the illumination provided. While during peak night-time traffic hours it may be desirable to operate the street lamps at full rated voltage, nevertheless in the middle night-time hours when traffic intensity is low and many people are asleep, municipalities for economic reasons may choose to operate street lamps at reduced power levels. Satisfactory control circuits to permit reduced power level operation (sufficient to provide satisfactory off-peak illumination) to occur automatically, subject to various overrides to deal with particular circumstances, are not readily available.
SUMMARY OF THE INVENTION
The invention is a load voltage and power control and supply system for the supply of power to a load for which, over particular periods of time, usually on a daily basis, it is desired to reduce power. The invention has particular application to street lighting systems and similar systems in which, for a period of several hours during the night (when traffic is minimal and many people are asleep), the lighting system can operate at reduced power. The system according to the invention is able to act as a voltage stabilizer as well as a controlled power reduction system.
The power control system according to the invention may operate the load from a single control location, even if the load is spatially dispersed, as in the case of a multiplicity of luminaires. Experience shows that moderately reduced power (say a 30% reduction in power) supplied to such luminaires does not appreciably diminish the adequacy of the illumination at such reduced power levels as compared with full-power illumination.
Further, the power control system is able to reduce power in stepwise decrements each of which reduces power by a small amount insufficient to diminish noticeably the ambient illumination.
In one aspect, the invention provides a power control unit for connection between a source of power and a load, and for control of power supplied to the load, comprising the combination of the following components:
1) a power supply circuit connectable to the power source for providing an output current at controllably variable output voltage levels over a range of voltage values (thereby to be able to effect a stepwise reduction in output voltage from the high end to the low end of the range);
2) a driver circuit (which may be integral with the power supply circuit) for driving the power supply circuit so as to set the output voltage level at which the output current is for the time being supplied to the load; and
3) a controller (preferably a microcontroller) for controlling the driver circuit to drive the power supply circuit to provide output power at a voltage set by the driver circuit in response to the controller. At the high end of the voltage range, the controller provides a signal to the driver circuit that compels the driver circuit to set a high output voltage level for the power supply circuit output so as to supply power at a set high-power setting. This high-power setting persists for a period of time T Hi starting upon the occurrence of a high-power start condition, and ending upon the occurrence of a high-power end condition. At the low end of the voltage range, the controller provides a signal to the driver circuit that compels the driver circuit to set a low output voltage level for the power supply circuit output so as to supply power to the load at a set low power for a later period of time T Lo starting upon the occurrence of a low-power start condition and ending upon the occurrence of a low-power end condition.
The controller in operation may transmit a sequence of control signals to the driver circuit to cause the driver circuit to (i) set the high output voltage level so as to supply power at the set high power setting for the period of time T Hi , (ii) set the low output voltage level so as to supply power to the load at the set low power for the period of time T Lo , and (iii) set a series of diminishing voltage levels during a transition period between time periods T Hi and T Lo . The time periods T Hi and T Lo may be recurrent, for example diurnally recurrent in the case of street lighting systems.
During the transition period following time period T Hi and preceding time period T Lo , the controller controls the driver circuit to set a series of output voltage levels for the power supply circuit diminishing controllably from the set high output voltage level to the set low output voltage level in accordance with selected characteristics of the load. Preferably the voltage is stepwise decremented from rated load voltage to a target reduced voltage level. In the case of a load constituting a bank of luminaires, the aforementioned selected characteristics may be, for example, (i) the maximum voltage drop that a luminaire may tolerate before snuffing out (which value may vary with the type of luminaire and the voltage prevailing when the voltage reduction occurs) and (ii) the maximum voltage reduction that can be effected without causing a noticeable reduction in illumination by the luminaires. This latter will be especially important in street lighting situations, because a noticeable reduction in illumination may impair vision or cause alarm to motorists passing by the luminaires. Accordingly, each sequential voltage reduction, proceeding from full rated voltage to target reduced voltage, will generally be selected to be less than the lesser of values (i) and (ii) above. The stepwise reductions may be selected to be some specified percentage of the previously prevailing voltage level.
The power control unit may advantageously including a sensor of supply current to the load, to which current the controller is responsive. During the transition period and after the supply current to the load has stabilized, the controller provides the next succeeding stepped output voltage level reduction.
The power control unit may include an autotransformer whose output is supplied to the load and whose output voltage level is variable in response to the driver circuit.
The power supply circuit may include a compensating transformer whose secondary winding is connected in series with the load and whose primary winding is connected between the center tap of the autotransformer and a variable tap on the autotransformer winding. The autotransformer is connected so that the secondary winding voltage is added to the output voltage of the autotransformer to constitute the output voltage level for supply to the load.
The driver circuit may include a servomotor connected to the variable tap on the autotransformer winding and responsive to the controller. In this case, the voltage applied to the primary winding of the compensating transformer is taken from the variable tap, whose position on the autotransformer winding is controlled by the servomotor in response to the controller.
The power supply circuit may in an alternative embodiment include an autotransformer whose winding is tapped at a first output tap that provides the high output voltage and also tapped at a second output tap that provides the low output voltage. Preferably one input terminal of the autotransformer is located at a tap positioned between the said output taps, and the other input terminal of the autotransformer is connected to the zero voltage point of its winding and to a second output terminal for connection to the other terminal of the load. The driver circuit may in such case comprise two pairs of inverse parallel-connected silicon-controlled rectifiers, each pair connected between a discrete tap and a first output terminal for connection to a terminal of the load. The silicon-controlled rectifiers respond to control by gate signals provided by the controller so as to supply output current to the load at controlled output voltage levels from the high to the low output voltage levels and to any set transitional output voltage levels.
In a further alternative embodiment, the power supply circuit includes an autotransformer whose winding is tapped separately at a first output tap corresponding to the high output voltage level, and at a second output tap corresponding to the low output voltage level, and by at least one further tap located at a point intermediate the first and second taps. This last tap corresponds to a transitional output voltage level intermediate the high output voltage level and the low output voltage level. The driver circuit in this case preferably comprises a set of triacs, each such triac being connected between a discrete tap and the load. The triacs individually respond to control by gate signals provided by the controller so as to supply output current to the load at a selected one of the high, the low, and any of the transitional output voltage levels.
SUMMARY OF THE DRAWINGS
FIG. 1 is a circuit diagram of a conventional photoelectric cell-controlled power supply circuit suitable for use with a street lighting system according to the invention.
FIG. 2 is a schematic block/circuit diagram illustrating in generalized configuration an embodiment of the power control and power supply circuit and system according to the invention.
FIGS. 3A and 3B are graphs showing stepwise voltage reduction as output power supplied by a system according to the invention is reduced from rated power to a pre-set reduced power level. The scales of the axes of graph shown in FIG. 3B are magnified relative to those of the graph shown in FIG. 3A; the intersection of the axes in FIG. 3B is not intended to represent a zero value of either voltage or time.
FIG. 4 is a flowchart illustrating the sequence of events in reducing output power supplied by a system according to the invention as power is reduced from rated power to a pre-set reduced power level.
FIG. 5A is a circuit diagram illustrating an embodiment of a power supply circuit that can be incorporated into the system of FIG. 2, employing triacs in conjunction with an autotransformer to supply a controlled output voltage to the load, in accordance with the present invention.
FIG. 5B is a circuit diagram illustrating a portion of power driver circuit suitable for use with the power supply circuit of FIG. 5 A.
FIG. 6 (on the same sheet as FIGS. 3A and 3B) is a circuit diagram illustrating a second embodiment of a power supply circuit that can be incorporated into the system of FIG. 2, employing a servo-motor in conjunction with an autotransformer to supply a controlled output voltage to the load, in accordance with the present invention.
FIG. 7A (on the same sheet as FIG. 1) is a circuit diagram illustrating a further embodiment of a power supply circuit that can be incorporated into the system of FIG. 2, employing silicon controlled rectifiers in conjunction with an autotransformer to supply a controlled output voltage to the load, in accordance with the present invention.
FIG. 7B (on the same sheet as FIG. 5B) is a circuit diagram illustrating an alternative power supply circuit equivalent to the circuit diagram shown in FIG. 7 A.
FIG. 8 is a set of graphs illustrating the operation of the circuit of FIG. 5A in output voltage stabilization mode.
FIG. 9 is a set of graphs illustrating the operation of the circuit of FIG. 6 in output voltage stabilization mode.
FIG. 10A, 10 B and 10 C are a set of graphs illustrating the operation of the circuit of FIG. 7A in output voltage stabilization mode.
FIG. 11 is a circuit diagram illustrating a power driver circuit suitable for use with the power supply circuit of FIG. 6 .
FIG. 12 is a circuit diagram illustrating an alternative power driver circuit suitable for use with the power supply circuit of FIG. 6 .
DETAILED DESCRIPTION
In this description, reference will be made to street light systems and luminaires for use with such systems, as such is the expected context for the principal implementation of the invention. However, the power control and supply system according to the invention has application, with appropriate modifications where needed, to other power supply applications in which a reduced supply of power is required over a specified time interval, particularly a specified periodically repeating time interval.
FIG. 1 is a schematic circuit diagram illustrating a suitable supply circuit of conventional design for a load power control device pursuant to the invention, e.g. for controlling electric power for street lighting. (Other such suitable circuits exist; the one chosen is exemplary.) In other words, the circuit of FIG. 1 is connected between mains high-voltage supply and the load power control circuit, e.g. street lighting control circuit, of the invention, one embodiment of which latter is illustrated in FIG. 2 . FIG. 1 does not per se depict any unconventional circuit arrangement, but rather represents a supply circuit that is suitable for use with the inventive control system. FIG. 1 includes an ambient light-responsive control device to control the availability of supply power, and thus is particularly suitable for street-lighting control.
Referring to FIG. 1, two-phase mains line voltage is supplied across terminals 12 and 14 between which the primary winding 16 of transformer 10 is connected. The secondary winding 18 of the transformer 10 is center-tapped at 20 to provide a common (in this case, neutral) supply line 21 ending in common (neutral) terminal 22 . The winding relationship between transformer winding 16 and 18 is selected to provide oppositely polarized operating voltages on supply lines 23 and 25 , respectively, relative to common line 21 . Supply lines 23 , 25 provide supply power to the power control device (e.g. of FIG. 2) via supply terminals 40 , 42 respectively relative to common terminal 22 . Note that power may be taken across as many as three pairs of terminals, viz ( 40 and 42 ), ( 40 and 22 ), and ( 42 30 and 22 ).
A manually operated breaker switch 24 comprising interlocked breaker contacts 26 , 28 is available to interrupt the supply circuit to the control apparatus to be described. Breaker switch 24 is series-connected in supply lines 23 , 25 and when open, prevents current flow to the output terminals 40 , 42 for supply lines 23 , 25 .
A photoelectric cell 30 reacts to changes in ambient light and closes associated photocell contact 32 when ambient light declines to a pre-set threshold level. When contact 32 closes, then (assuming breaker contacts 26 , 28 are closed), current flows through relay coil 34 which, when actuated, closes normally open contacts 36 , 38 , respectively, thereby providing supply voltage at terminals 40 and 42 (relative to common terminal 22 ). In operation, in daylight, normally open contacts 36 , 38 remain open, so that there is no supply power available from terminals 22 , 40 , 42 ; when evening arrives and ambient light declines below the pre-set threshold level for photocell 30 , contacts 32 close, causing relay coil 34 to close relay contacts 36 , 38 , thereby making available supply power at terminals 22 , 40 , 42 .
When dawn breaks and ambient light returns to an adequate threshold level of brightness, contact 32 opens, resulting in the cessation of current supply to relay coil 34 , and as a consequence, contacts 36 and 38 re-open, interrupting the current supply via supply terminals 22 , 40 , 42 to the load power control circuitry to be described below with reference to FIGS. 2 ff.
In FIG. 1, contact 32 is shown driven by a photoelectric cell 30 , but it is to be understood that the master control for the supply circuit may, instead of a photoelectric cell, be a timer or other suitable control element (including a manually operable switch).
FIG. 2 is a schematic block/circuit diagram of the gross structure of load power control circuitry for load power control pursuant to the present invention. Input supply terminals 40 and 22 for the diagram of FIG. 2 appear as the output supply terminals for the circuit of FIG. 1 . FIG. 2 is schematic, borrowing some elements of conventional circuit diagram depiction and some elements of block diagram or flowchart depiction, for simplification of the discussion. Further, although FIG. 1 illustrates output terminals for two opposed polarities and a neutral, FIG. 2 ignores one of the polarities and shows terminals for only one polarity and the neutral as its input. For simplification, FIG. 2 presents only one “live” line, it being understood that what is illustrated in FIG. 2 can be extrapolated into a complete circuit diagram by any competent circuit designer, with the aid of the following description.
Portions of FIG. 2, particularly what is seen in the upper part of the diagram, for convenience of illustration, are presented in conventional electric circuit diagram format. But as mentioned, the circuitry of FIG. 2 is incomplete; not all of the common line connections for various of the operating elements are shown and instead a flowchart approach to the various control loops etc. is taken. It is to be understood that appropriate circuit completion connections will be arranged as required to give structural and operational effect to the elements of FIG. 2 to be described.
The circuit of FIG. 2 can be implemented using analog circuit means, in which case operational amplifiers or equivalent analog logic devices to establish references, comparisons and control signals may be advantageous. Further, it is possible to substitute alternative system components for various of those appearing in FIG. 2, as will be apparent to those skilled in circuit design. However, it is convenient to implement the control aspects of the circuit of FIG. 2 using a microcontroller and related digital circuitry. For convenience, such digital control implementation is embodied in the diagram of FIG. 2 in flowchart representation. It is to be understood that where necessary, appropriate analog/digital converters will be provided by the circuit designer to implement the design to be described.
The conventional circuit presentation portion of FIG. 2 establishes that input voltage and current from input terminals 40 , 22 flows to output terminals 56 , 60 via an intervening load power supply circuit 52 connected therebetween.
The load power supply circuit 52 is driven by a power driver 65 under the control of microcontroller 74 acting in response to certain reference, pre-settable and feedback inputs, as designed. Among these reference settings may be:
1) a specified time or time interval during which reduced output power is to be provided, as set by a timer clock 86 ;
2) seasonal reference settings, if desired;
3) a setting for the limit of stepwise incremental increases or decreases in output voltage, if such adjustment is needed, as by voltage reference settings 84 ;
4) a setting for the time of day at which the load power control circuit becomes operational and/or non-operational (if desired in addition to the control provided by the circuit of FIG. 1, and possibly subject to overriding or complementary other inputs, such as
5) a seasonal override setting 88 ; and
6) control over the amount (percent, or absolute value) of power reduction required during reduced power operation of the control circuitry, as by output power reference setting 82 .
Some of the reference settings are time settings, such as the clock time or time interval setting and the seasonal override setting. Others are value settings, such as the reduced load power setting (which may be a specific load power selection or a specified percentage of supply power or may be expressed in terms of load supply voltage or current). The load power supply circuit 52 may be bypassed if desired by closing normally open manually operable switch 80 connected across the power supply circuit 52 . The bypass operation can be automatically performed in the event of overload, such as by a short circuit or other failure (in which event, a circuit breaker, fuse or the like not illustrated in FIG. 2 will open the input power supply to circuit 52 , thereby eliminating any short-circuit problem that may be internal to the power supply control system according to the invention; on the other hand, if the short circuit is in the load, the usual mains supply circuit breaker will open upstream of the terminals 40 , 22 ).
Some or all of the settings described above may, instead of being made available to the operator as dial or switch settings or the like, be incorporated into the operating software for the microcontroller 74 .
The microcontroller 74 may be any suitable microcontroller available in the market, having adjustable pre-settable time and value reference inputs and responsive also to feedback for parameter comparison purposes. As mentioned, such inputs and control response thereto may be software-effected rather than hardware-effected, depending upon the microcontroller selected. It is up to the designer to decide how many different inputs should be provided to the microcontroller 74 , having due regard to the need for some types of output loads to be precisely regulated, in turn requiring a number of different inputs in order to provide such precise regulation; whereas for other types of loads, a coarser, simpler approach to load power control may be quite satisfactory. Further, some designers or their customers may not wish to provide, for example, a seasonal override on the duration of the reduced power operation period, in which case the seasonal override setting 88 may be omitted.
In the system illustrated in FIG. 2, the microcontroller 74 is shown as responding to pre-settable output load power references 82 , pre-settable output voltage references 84 , a timer clock 86 and a voltage reduction decrement reference 90 . Such reference settings may be effected by suitable hardware settings on trim pots or dip switches, for example, or by means of software parameter selections. The microcontroller 74 is also responsive to three feedback signals, namely a load current signal 100 , a load voltage signal 102 and a load power computation signal 104 . As mentioned, suitable analog/digital converters (not shown) would be routinely provided to enable the microcontroller 74 to operate digitally on digital values obtained by conversion of analog measurements.
The pre-settable output power references 82 would typically be one or two reference signals—one for full rated power supplied to the load (this reference may not be necessary for some control applications), and the other for a reduced load power level chosen by the user of the power supply system. Instead of establishing a specific reduced output load power, the user may select instead a given power reduction expressed as a percent—for example a 30% power reduction from rated power, or as the case may be.
The pre-settable output voltage references 84 can be two in number, namely a rated nominal voltage for full power delivered to the load to be connected across output terminals 56 and 60 , and a reduced voltage reference that corresponds to the reduced output power desired. Alternatively, the latter reference can be supplied as a reduced output power reference 82 .
The timer clock 86 may establish both the onset and the duration of the period of time during which reduced power will be provided to the load; alternatively, the onset can be measured from a start time determined by the photocell 30 of FIG. 1 . The timer 86 and/or the microcontroller 74 may receive additional inputs such as a seasonal override input 88 that would on a seasonal basis vary either the duration of the reduced power period or the timing of its onset—for example, input 88 could take into account the changeover from standard time to daylight saving time, and could take into account the fact that in the winter months, dusk arrives earlier than in the summer months, although for some situations it would be expected that this latter aspect of the control of the power supply would primarily be governed by the photocell circuitry of FIG. 1 rather than by the program circuitry of FIG. 2 . Further reference inputs (not shown) to the timer 86 and/or microcontroller 74 might include, for example, a reset signal to reset the time if there has been an electrical power interruption, etc.
Reduced power output to the load may be effected by maintaining load current relatively constant while reducing load voltage. For some types of load, for example high voltage discharge lamps, it is not possible to reduce applied load voltage in a single reduction of, for example, 30% while maintaining illumination—the lamps cut out in response to such large voltage changes and have to be restarted. So instead of effecting a 30% (say) voltage reduction in one step, the microcontroller 74 is selected, designed or programmed to provide a series of decremental voltage reductions, each one of which is sufficiently small that the luminaires do not snuff out; no interruption of illumination occurs (in the case of a luminaire load). Because the properties of luminaires and the like may vary from type to type and brand to brand, the magnitude of the voltage reduction decrement may have to be varied from one situation to another. For that purpose, a voltage reduction decrement reference input 90 can be made available to the microcontroller 74 . This reference can of course be omitted if only one type of lamp will be used and if the microcontroller is set or programmed to reduce voltage by decrements that such lamps will tolerate.
Further, because the particular lamps or other loads connected to the output terminals 56 , 60 may have variable response to any particular load voltage change (and particularly, may have a varying response time required to regain stability following a voltage change) it is important that any decremental reduction proceed only if the load current has regained sufficient stability. For that purpose, and also to enable the microcontroller 74 to stabilize the load voltage during steady-state operation, suitable feedback signals, illustrated in FIG. 2 as constituting load current 100 , load voltage 102 and load power computation 104 , are provided to microcontroller 74 for comparison with target values. For example, the microcontroller 74 compares actual load voltage with the target voltage signal established for the time being (as determined initially by the signals received from references 84 , 90 , and as re-set as the load voltage declines through a series of decremental steps). In operation, the microcontroller 74 maintains a particular interim target voltage level, sending a correlated output voltage control signal to the power driver 65 accordingly, for as long as the differential between that target voltage level and the voltage level feedback signal 102 exceeds some pre-set threshold. Once the voltage differential drops below that threshold level, and after load current has stabilized at the interim target voltage established by the microcontroller 74 , the microcontroller 74 responds by setting a fresh interim target voltage that is lower by the amount of the pre-set decrement than the immediately preceding target voltage.
Furthermore, if there has been a power interruption or some other unusual circumstance on the line, the feedback reference signals 100 , 102 and 104 can govern the operation of the microcontroller 74 suitably; if there has been only a short interruption of supply power at input terminals 40 , 22 , it may be possible to resume supplying power to the load without going through a fresh start-up cycle for the load, because in that event the probability is that the luminaires will not have been extinguished. On the other hand, if the power interruption (say) at the input terminals 40 , 42 has existed for an appreciable period of time (more than about 10 msec, in the case of HID luminaires, for example), the luminaires (say) will have turned off and in that event it will probably be necessary to go through another warm-up cycle in order to have the luminaire load connected across output terminals 56 , 60 restart and regain steady-state operation. Typically, in such latter circumstances, the luminaires are restored to operation at full rated power before any voltage reduction occurs to re-establish the reduced power mode of operation. Accordingly, the microcontroller responds in either a “resume operation” control mode or a “warm-up” control mode, depending upon whether the luminaires are on or off. As mentioned, the “warm-up” control mode will typically require the furnishing to the luminaires of full rated voltage, following which, if the pre-set time interval for the reduced-power mode of operation has not yet expired, the microcontroller 74 can repeat the decremental voltage reduction steps previously described.
In the following discussion and in the claims, the conditions, as defined by the values of the reference, pre-settable and feedback inputs discussed above, under which the microcontroller 74 is programmed to set a high output voltage level so as to supply power at a high power setting (typically full rated power) are referred to as high power start conditions. The conditions, as defined by the values of those inputs, under which the microcontroller 74 is programmed to set an output voltage level differing from the high output voltage level so as to stop supplying power at the set high-power setting are referred to as high-power end conditions. Similarly, the conditions, as defined by those inputs discussed above, under which the microcontroller 74 is programmed to set a low output voltage level so as to supply power at a set low (reduced) power setting are referred to as low-power start conditions, and the conditions under which the microcontroller 74 is programmed to set an output voltage level differing from the low output voltage level so as to stop supplying power at the set low-power setting are referred to as low-power end conditions. The period of time between the occurrence of a high-power start condition and the next high-power end condition is referred to as a high-power period, sometimes abbreviated as T Hi , and, similarly, the period of time between the occurrence of a low-power start condition and the next low-power end condition is referred to as a low-power period, sometimes referred to as T Lo .
Under normal operating conditions, following a high-power period T Hi and before a low-power period T Lo is due to start, a transition period is provided during which the microcontroller 74 in response to the inputs discussed above sets a series of voltage levels diminishing controllably from the set high output voltage level to the set low output voltage level in accordance with selected characteristics of the load. For example, the duration of the transition period may vary depending upon ambient temperature, age and condition of the luminaires comprising the load and other factors.
The microcontroller 74 , in response to each of the inputs already discussed and any others that may be desired by the designer, provides a drive signal to power driver 65 , which latter may be a driver circuit suitable for supplying the gate control voltages at gate terminals 641 , etc. of the various silicon-controlled rectifiers S 1 , etc. illustrated in FIG. 7A, or the gate control voltages at gate terminals 64 A, etc. of the various for the triacs Z 1 , etc. illustrated in FIG. 5 A. Or the power driver 65 may instead provide a control signal to servo-motor 170 of FIG. 6 . Other types of power driver may be designed that would be suitable for adjusting output voltage and power in a suitable power supply circuit. In each case, if a digital microcontroller is chosen, it will be necessary to convert the digital signal to analog and typically also to amplify it in some suitable way (e.g. by power amplifier or relay) so that a suitable power circuit drive signal 64 may be provided. The preferred design choices of output power supply circuit 52 established in accordance with the present invention are those illustrated in FIGS. 5A, 6 and 7 A (or 7 B), but other choices might be entirely suitable for various loads, in the designer's preference. Suitable power driver circuits for power supply circuits illustrated in FIGS. 5A and 6 are illustrated in FIGS. 5B (for the FIG. 5A power supply circuit) and FIGS. 11 and 12 (for the FIG. 6 power supply circuit). No power driver circuit shown for the power supply circuit illustrated in FIG. 7A (or 7 B), but if necessary a power amplifier or relay may be provided.
Note that some of the elements shown as discrete blocks in FIG. 2 (e.g., load power computation block 104 ) may in fact be incorporated into the microcontroller 74 . Further, as mentioned, some of the elements shown as discrete blocks in FIG. 2 (e.g. selected ones of the blocks 82 , 84 , 86 , 88 ) may operate merely as reference values in software governing the operation of microcontroller 74 . So, for example, instead of generating a seasonal override 88 as a discrete input to either the timer clock 86 or the microcontroller 74 , that seasonal override could be simply a value in a software program governing the operation of the microcontroller 74 in its provision of a given output signal to the power driver 65 at any particular time of any particular day of the year. So it is within the discretion of the designer to use various discrete logic elements in conjunction with the microcontroller 74 or to have the microcontroller 74 itself perform the logical operations under the control of a hard-wired logic circuit or under the control of suitable software, depending upon the particular type of microcontroller chosen and the particular circumstances of the load being regulated.
In the particular system illustrated in FIG. 2, the feedback load current is obtained with the assistance of a current transformer 92 connected between power supply circuit 52 and output “hot” terminal 56 , which current transformer 92 provides a load current reading 100 to the microcontroller 74 . The load voltage feedback is obtained with the assistance of a transformer 94 whose primary winding 96 is connected across output terminals 56 and 60 and whose secondary winding 98 provides a load voltage signal provided as feedback load voltage input 102 to the microcontroller 74 . Further, the load current values and load voltage values obtained from current transformer 92 and transformer 94 , respectively, are fed to a load power computation circuit 104 that provides a computed load power signal to microcontroller 74 . Again, this computation shown as performed in a separate logic operation box 104 could be integrated with the microcontroller logic within microcontroller 74 , either in hardware or software format. Again, suitable analog to digital conversion is routinely provided as required.
The microcontroller 74 of FIG. 2 may be any suitable commercially available microcontroller programmable to accept the inputs and provide the outputs illustrated in FIG. 2 and any others deemed suitable by the circuit designer. A suitable such microcontroller could be, for example, any of the microcontrollers in the Microchip PIC16C62X and PIC167X families.
FIGS. 3A and 3B illustrate graphically the manner in which the microcontroller 74 reduces the load voltage V L from full load voltage V F to a steady-state reduced voltage value V R . In both of these FIGS. 3A and 3B, load voltage V L is plotted against time T.
At a start time T S , voltage is applied to the load at full rated voltage V F , for example as a consequence of the closing of contacts 36 , 38 (FIG. 1) or in response to some other suitable start signal. Assuming that the load is a bank of luminaires, full load voltage V F would be applied over a period of time during the early hours of the night until the pre-set time T T is reached at which voltage reduction is intended to commence. At that time T T , the microcontroller 74 arranges a step-wise reduction in the load voltage V L until a steady state-reduced voltage V R is reached, which voltage V R persists until either the supply of electric power to the load is discontinued, or full load voltage is resumed, or otherwise in accordance with the designer's preference.
The step-wise reduction in voltage during the transition period between times T T and T R can be better understood with reference to FIG. 3 B. FIG. 3B illustrates (on magnified scales of V L and T) a portion of the transitional voltage curve of FIG. 3A over an intermediate time span between times T T and T R . Assume that over a time interval T 1 , voltage V 1 is applied to the load. The end of time interval T 1 is determined by the microcontroller 74 , which, in response to load current sensor input 100 , has determined that the load current is stable and, therefore, the microcontroller 74 arranges a decremental load voltage reduction to a fresh load voltage value V 2 . Typically the voltage differential between values V 1 and V 2 is a fixed percentage (for example, 1.5%) of the value of the immediately preceding voltage V 1 . Voltage V 2 is maintained over a period of time T 2 of unpredictable duration; the time interval again is determined by the microcontroller 74 when the microcontroller 74 senses that the load current is stable. At the end of time interval T 2 , the microcontroller 74 causes a further step-wise reduction in voltage to a fresh voltage level V 3 . The voltage differential (V 2 -V 3 ) is again a fixed percentage of the immediately preceding voltage value V 2 . This step-wise reduction in voltage continues; voltage V 3 persisting over a time interval T 3 , voltage V 4 over a time interval T 4 , and so forth as voltages V 3 , V 4 , V 5 , etc. become progressively smaller, in each case diminishing by a voltage differential value that is a fixed percentage (within engineering limits) of the immediately preceding value. The respective set voltages V 3 , V 4 , V 5 , etc. persist over time intervals T 3 , T 4 , T 5 , etc., in each case, the time interval ending when the microcontroller 74 has determined that the load current is stable.
Note that although the voltage reductions illustrated in FIG. 3B are fixed by the microcontroller 74 at set voltage levels that differ from the preceding voltage value by a fixed percentage, the time intervals T 1 , T 2 , T 3 , etc. are unpredictable; the time interval required to permit load current to resume a stable value may depend upon ambient conditions, the inherent characteristics of the luminaires in the load, etc., and as a result these various time intervals T 1 , T 2 , T 3 , etc. are quite variable in length and not necessarily correlatable with the voltage values V 1 , V 2 , V 3 , etc.
In order to give effect to a progressive voltage reduction as illustrated in FIGS. 3A and 3B, the microcontroller 74 performs a series of monitoring and comparison operations and provides a number of output control signals, as better understood with reference to the flow chart of FIG. 4 . The flowchart of FIG. 4 graphically depicts the human and microcontroller operations and decisions to be effected.
Referring to FIGS. 2 and 4, the operator will normally set full power output voltage reference of the references 84 to microcontroller 74 to rated nominal voltage for full power. Typically, reference settings into the microcontroller 74 are effected using suitable conventional settable control elements, for example, dip switches and trimming potentiometers (trim pots).
The operator will also establish the pre-settable output power reference 82 in one of several convenient ways. The target reduced output power reference 82 may be set (i) as a specific power value; (ii) as a percentage of maximum rated output power; or instead, assuming relatively constant current flow to the output load, (iii) as a specific reduced output voltage or as a percentage of maximum output voltage, according to the demands of the particular load to be regulated. In many instances, it will be found more convenient to set a reduced output voltage level instead of a reduced output power level, recognizing that the output power will drop in accordance with the reduced output voltage, in which case the reduced voltage output voltage reference of the references 84 will be set by the operator.
The operator will also have to set whatever timing instructions are necessary for the intended operation of the load power control circuit of FIG. 2 by adjusting the timer-clock 86 , the seasonal override 88 , and any other time related references that may be desired as inputs to the microcontroller 74 . In at least some applications, there is available a basic clock setting establishing year, month, day of the month, and time. Also, the operator will set a power reduction commencement time for the beginning of the power reduction to the load, and a termination time at which reduced output power to the load is discontinued, at which latter time the load power setting is returned to full load power (or optionally, may be shut off entirely at dawn, or as the operator may prefer).
The seasonal override 88 illustrated in FIG. 2 is an example of a refinement that may or may not be present in commercial systems, according to the designer's preference; further, other time inputs not now shown in FIG. 2 could be provided. For example, the pre-settable reduced output power reference 82 might be a pair of reference power settings or voltage settings instead of a single voltage or power reference. For example, it might be desired to operate street lamps over the initial portion of a reduced power time interval at, for example, 75 percent of full rated power, and thereafter to make a further reduction in output power to, say, 60 percent of full rated power, or as the case may be, in which case the timer clock 86 would be set to establish the commencement period and termination period for each of the two sequential reductions of output power to the load.
The voltage reduction decrement reference 90 may also be set by means of a dip switch or the like; this reference setting establishes the decremental voltage drop or the percentage voltage reduction to occur at each step of a step-wise series of voltage reductions. The maximum amount of voltage reduction tolerated in a given step without causing interruption of illumination in street lamps (luminaires) is dependent upon the type of luminaires present in the load. In some cases, it may be desired not to reduce voltage (and thus power) in any given step by the maximum tolerated by the luminaires, but to select some lesser stepwise reduction, in the interest of avoiding a negative reaction from the human eye. It is desired that the sequential changes in illumination be substantially imperceptible to the eye, and thus reductions of about 1.5% or less are preferred (and may be required by law, in order to avoid any illumination-reduction hazard to motorists). Typically, voltage reductions are desired as a percentage of the immediately preceding voltage level.
So far, all of the settings discussed above relative to timer clock 86 , seasonal override 88 , output full power voltage reference 84 , reduced output power reference 82 and voltage reduction decrement reference 90 have been discussed on the basis that manually adjustable dip switches, trim pots, etc., may be manually controlled. Nevertheless, as discussed, it is possible for any or all of the foregoing control settings to be incorporated not as manually operated switches providing a reference for microcontroller 74 , but instead to be set as settable values within the computer program that controls the operation of microcontroller 74 . If the load is expected to be constant and if no adjustment or only rarely occurring adjustment of any of the reference values is likely to be needed, then it is probably more convenient to establish the reference values as set values within the computer program controlling microcontroller 74 . Accordingly, some or all of the boxes 82 , 84 , 86 , 88 , 90 and any other settable values considered desirable by the designer may optionally be integrated into the computer program as operator-selected values within the program.
Once the various reference settings required for control of the system have been set either by way of program or manual setting (both of which can be arranged to be set remotely, if required, by means of conventional communications links), the system is ready to operate. The microcontroller 74 not only receives the set values but also monitors selected circuit parameters to compare the reference settings to those relating to the state of the circuit of FIG. 2 during any given monitoring cycle. For this purpose, the microcontroller 74 reads the pre-set reference levels from the dip switches, trim pots, or other manually adjustable equipment and/or program software reference settings, and also at least the present values of load current (box 100 ) and load voltage (box 102 ) during any given monitoring cycle. The monitoring of load power (box 104 ) is optional because load power is a function of load current and load voltage, but because there will normally be both a resistive and a reactive component of load power, a separate monitoring of load power is desirable, at least for many types of load.
During normal default operation, the microcontroller 74 will cycle through a sequence of monitoring and comparison cycles on a continuous basis as rapidly as the speed of operation of microcontroller 74 permits, or more slowly than this if the operating program for microcontroller 74 so provides. Once a comparison of reference settings to present operating values of the parameters selected for monitoring and comparison has occurred, the microcontroller 74 will send to the power driver 65 a power control signal that will operate the power supply circuit in such a way as to provide a power level for the load that is determined by the microcontroller 74 in response to its operating program. Absent any program direction otherwise, the microcontroller 74 will send a control signal to power driver 65 so that the power supply circuit 52 under the control of power driver 65 will provide full output power to the load. (Of course, as evident from FIG. 1, if the load is a bank of luminaires, power to the load will normally be interrupted during daylight hours, as determined by the photo-electric control circuit of FIG. 1.)
For a given maximum rated power and also for luminaire start-up conditions, the power supply circuit 52 would normally be expected to operate at full rated output voltage. Accordingly, the output signal from microcontroller 74 to power driver 65 would, in the default full-power mode of operation, provide an output drive signal 64 that would constrain the power supply circuit 52 to operate at full output voltage and therefore at full output power once the load has reached steady-state operation.
With regard to the latter, the microcontroller 74 is necessarily sensitive to the need for an initial warm-up time for the luminaires or any other load that may require a warm-up. If the warm-up time has not expired or if the load current has not reached steady state stability for some other reason, the microcontroller 74 operates on a recycle basis (indicated by the “no” option at the first two points of decision in the flowchart of FIG. 4) and continues to monitor the stability of the current (via load current sensor 100 coupled to current transformer 92 ) until such time as current stability is indicated. Warm-up times suitable for given luminaires are often recommended by the manufacturers of the luminaires, or may be determined empirically.
Load current stability may be determined by the microcontroller 74 under the direction of the software program. For example, the microcontroller 74 may generate a running average value for load current over a predetermined number of successive samplings of the load current, the average value being continually updated. If the load current in any sample or perhaps any pair of successive samples does not diverge by more than a pre-set amount or percentage (say, less than 3%) from the average value, the load current is treated by the microcontroller 74 as being stable. Note that as normal fluctuations in load voltage may rise to about the 1% level or so, the microcontroller's threshold for active response to a computed divergence from average should not be set too low, or unwanted “hunting” oscillations in the system may develop.
Once the warm-up time required for the luminaires (or other load requiring a warm-up time) has expired and the sensed load current reading feedback signal 100 provided by current transformer 92 has reached a steady-state level, then normally no change in the output control signal from microcontroller 74 to power driver 65 will occur until such time as a reduced output power is required. This implies that the output signal from microcontroller 74 to the power driver 65 , and the drive signal 64 provided by power driver 65 to the power supply circuit 52 , will remain constant so as to cause power supply circuit 52 to provide maximum output power and voltage to the load until such time as reduced power is required. However, the system of FIG. 2 provides not only controlled load power reduction, but also stability of load voltage; the latter function will be described further below.
The setting of the timer clock 86 , or some equivalent programmed time-setting, establishes the commencement of the power reduction cycle. The third decision box in the flowchart of FIG. 4 must be answered YES, viz that the commencement time for reducing the load power has been reached, before the microcontroller 74 proceeds to the lower portion of the flowchart of FIG. 4 . Prior to that time, the microcontroller 74 remains in full output power/full output voltage mode. Note that the initiation of the load power reduction cycle may be made at some specified time of the day, or may instead be made at some specified time interval following the application of power to the load when switch terminals 36 and 38 (FIG. 1) are closed, or otherwise as the operating program for microcontroller 74 may direct. The latter option mentioned above, viz initiating the power reduction at some specified time interval following the closing of switch terminals 36 and 38 may be preferred for some applications if reduced power is desired at a specified time interval after dusk.
Whatever time setting is chosen for initiation of load power reduction, once the reduced power mode of operation is to begin, the microcontroller 74 , now operating in the lower portion of the flowchart of FIG. 4, performs the usual monitoring and comparison functions, confirms that interim target load voltage has been reached and that the load current is stable, and then decrements the output voltage by a pre-set amount or (preferably in the case of luminaires) by a pre-set percentage of the previously prevailing voltage level. “Decrements the output voltage” is a shorthand way of saying that the control signal provided by the microcontroller 74 sent to power driver 65 will be varied to cause the power driver 65 in turn to send a changed control signal 64 to the power supply circuit 52 . The character of the change in the control signal 64 depends upon the character of the power supply circuit 52 . For some such power supply circuits, the control signal 64 might be a voltage signal of reduced value that directly forces a reduction in the output voltage of the power supply circuit 52 . In other such power supply circuits, the control signal 64 is a timing signal that turns the power supply circuit 52 on or off or both for a selected portion of one complete AC operating cycle of the power supply circuit 52 . (In North America, one complete cycle is {fraction (1/60)} second; in Europe one complete cycle is {fraction (1/50)} second.) Regardless of the specific control method chosen, the decremented voltage is preserved as a new immediate target voltage to be supplied to the load, and a corresponding control signal of appropriate value is applied by the microcontroller 74 as an input to the power driver 65 . The power driver 65 in turn supplies a drive signal to the power supply circuit 52 that responds to reduce the output voltage applied to the load across terminals 56 and 60 . In some designs (for example, the design shown in FIG. 7A) the function of the power driver 65 may be incorporated into the microcontroller 74 so that the microcontroller 74 provides the drive signal 64 directly to the power supply circuit 52 .
The microcontroller 74 , after effecting a step-wise decrement of target voltage as a fresh reference voltage to be applied to the load, will continually monitor the load current feedback signal 100 provided by current transformer 92 to determine whether the load current has reached stability. Immediately following each decrement of target output voltage, the load current will typically not be stable for a period of time (the length of the period of time during which instability persists being, to a certain extent, unpredictable and dependent upon the characteristics of the luminaires or other load being powered). Accordingly, a decision box in the lower portion of the flowchart of FIG. 4 requires the microcontroller 74 to determine not only whether the desired output voltage decrement has been achieved but also whether stability of current has been achieved. If the answer to either of these questions is NO, then the microcontroller 74 continues to recycle through the steps in the lower portion of the flowchart of FIG. 4 until such time as current stability has been achieved at the immediately preceding target reduced voltage. Once that voltage reduction has been achieved, the microcontroller 74 decrements the voltage by the prescribed amount and a fresh target voltage is establish. Successive voltage decrements and a corresponding succession of fresh target voltages are made, at each step waiting for load current to stabilize before initiating a further load voltage decrement, until the final target reduced load voltage is reached. At that point, no further decrements occur, and the load is maintained at ultimate target reduced voltage (and correspondingly reduced power) until the time is reached (typically a short time before dawn) that full load power is to be resumed, or (if the operator prefers) load power is interrupted until the next following evening, or as the case may be, at which time the entire operation in conformity with the flowchart of FIG. 4, or as the case may be, is repeated.
Note that variants and options are readily substitutable for what is set out in the exemplary flowchart of FIG. 4 . For example, the preferred sequence of at least some of the decision steps can be varied. Given the objective of reaching both target voltage and stable current before a change in circuit conditions is effected, it follows that the microcontroller could test load voltage before it tests load current, or vice versa, without any substantive change in overall operation. Similar such variations, modifications and refinements can be made relative to other boxes in the flowchart of FIG. 4 . And of course if the load is not a controlled set of luminaires but some other load, the flowchart might have to be quite drastically revised.
Note also that for convenience of operation, at any point in the circuit of FIG. 2, and at any stage of operation of the microcontroller 74 , the values for voltages, currents, power levels, etc. at various points in the circuit may be displayed to the operator. Such display may include any desired combination of pre-set parameters (e.g., voltage settings) or monitored parameters (e.g., measured voltage values at selected points in the circuit of FIG. 2 ). Such displays may conveniently be effected by any suitable display device, such as light-emitting diode (“LED”) displays (not illustrated in the drawings). The display may also indicate whether the microcontroller 74 is operating in default full-power mode, or in power reduction mode.
FIG. 5A illustrates an example of a power supply circuit corresponding to power supply circuit 52 illustrated in FIG. 2 . FIG. 5B illustrates a portion of a power driver circuit corresponding to power driver 65 illustrated in FIG. 2 for driving the power supply circuit shown in FIG. 5 A.
In FIG. 5A, voltage V in is applied across input terminals 40 , 22 of autotransformer 110 . The autotransformer 110 is provided with at least one voltage increment winding 130 , and a series of voltage decrement windings 132 , 134 , 136 , 138 , 140 , and what is indicated as a lowermost voltage decrement winding 150 .
A bank of parallel-connected triacs Z 2 , Z 3 , Z 4 , Z 5 , Z 6 are connected between “live” output terminal 56 and a series of discrete tapping points between successive winding intervals of the autotransformer 110 , the uppermost triac Z 1 being connected to the high-voltage end of voltage increment winding 130 and in parallel with the other triacs Z 2 , etc. The broken line between circuit points 48 and 58 is intended to indicate that further voltage decrement windings could be provided on the autotransformer 110 , and further parallel-connected triacs could be connected between discrete successive pairs of further autotransformer decrement windings and output terminal 56 , in essentially the same manner as triacs Z 2 through Z 6 are connected.
The gates of triacs Z 1 , Z 2 , Z 3 , Z 4 , Z 5 , Z 6 are operated under the control of gate signals 641 , 642 , 643 , 644 , 645 , and 646 respectively, corresponding collectively to the control signal 64 illustrated in FIG. 2 . Each gate signal 641 , etc. may be provided by a discrete optically isolated triac driver in the manner illustrated in FIG. 5 B and discussed in detail below in relation to power driver circuits or the microcontroller 74 may be connected directly to the triacs Z 1 , etc. by a set of control lines, if necessary with power amplifiers or relays to increase the magnitude of the output drive signals.
Common input terminal 22 and common output terminal 60 may be a single terminal.
Because it is expected that a controlled voltage reduction in the output voltage will proceed in a step-wise decremental fashion, as discussed above, as many autotransformer voltage decrement windings and as many associated triacs will be provided as are needed to effect suitable controlled stepwise voltage reduction.
If only one voltage increment winding 130 is provided it should be selected or designed to provide the maximum additional voltage required to compensate for the greatest negative voltage fluctuation expected in the input voltage V in . Additional intermediate incremental voltage windings (or taps on winding 130 ) may be used if finer control over full power voltage is desired under low input voltage V in conditions. The voltage decrement windings 132 , 134 , 136 , etc. provide a selection of voltage decrements sufficient to compensate for positive voltage fluctuation in the input voltage V in when full power voltage is desired and in addition provide the controlled step-wise reduction of output voltage from rated full-power voltage to the reduced voltage required to drive the output load at a predetermined reduced power setting.
Note that it is possible, in the circuit of FIG. 5A, to provide larger or smaller voltage decrements for the decrement windings by having a smaller or greater number of voltage decrement windings available to span the total expected voltage differential to be accommodated. With fewer voltage decrement windings, fewer triacs are required, and the manufacturing expense is consequently lower. The trade-off is between cost and fine control of the output voltage. Note that an equivalent such circuit using a conventional transformer rather than an autotransformer may be substituted; such substitution is within the skill of circuit designers and requires no elaboration.
The operation of the circuit of FIG. 5A can be further understood by referring to FIG. 8, which comprises two synchronized hypothetical waveform Graphs A and B. In this particular illustration, the operation of the circuit of FIG. 5A in voltage stablization mode is being analyzed. In Graph A, instantaneous AC voltage is plotted as a function of time, and plots are shown for input voltage V in and output voltage V out in the circuit of FIG. 5 A.
In the first cycle of the waveform shown in Graph A, the input voltage V in is equal to the output voltage V out . The microcontroller 74 , sensing the equality of the input and output voltages, and finding that the output voltage V out is at the target reference value, causes a control signal 642 to be sent to the gate of triac Z 2 , causing triac Z 2 to conduct current throughout the entirety of the AC cycle in the first panel of Graph A, corresponding to the first AC cycle illustrated. In other words, there will be in effect a direct conductive circuit between input terminal 40 and output terminal 56 .
Graph B, vertically aligned along the time axis with Graph A, again plots voltage against time, in this case the voltage drop across selected ones of various of the triacs Z 1 , etc. In the first panel, corresponding to the first AC cycle of Graph A, Graph B illustrates the fact that triac Z 2 is fully conducting during the first AC cycle; voltage drop V 2 across the triac Z 2 is minimal (approximately 1 volt) and is uninterrupted from the beginning to the end of the AC cycle illustrated.
If the input voltage V in rises above rated level as in the second AC cycle illustrated in Graph A of FIG. 8, then the circuit of FIG. 5A must compensate for the increase so as to maintain the output voltage V out as constant as possible. Microcontroller 74 , having sensed the increase in input voltage V in , will in response to that increase provide a control signal to the gate of a selected one of the triacs Z 3 , Z 4 , Z 5 , Z 6 rendering it conductive. Assuming that the required decrement is best provided by decrement winding 132 , the microcontroller 74 will provide a control signal 643 to the gate of triac Z 3 . Since the triac Z 3 is tapped into autotransformer 110 at a point below the first voltage decrement winding 132 , it follows that, the voltage V out at output terminal 56 will be lower than the voltage at input terminal 40 . The triac Z 3 will conduct through the complete AC cycle as illustrated in the second panel of Graph B. In the second AC cycle, it can be seen that the voltage drop V 3 across triac Z 3 is minimal (approximately 1 volt), indicating that the triac Z 3 is fully conductive throughout the entirety of the AC cycle illustrated.
Note that in the second panels of Graphs A and B it has been assumed that decrement winding 132 provides exactly the necessary voltage decrement to compensate for the increase in input voltage V in . This will not always be the case; in most situations the microcontroller 74 will have to select the triac connected to a tap of the autotransformer 110 that provides output voltage V out closest to the desired output voltage V out .
If the input voltage V in is lower than the target output voltage V out , then a voltage increment must be supplied by the circuit of FIG. 5 A. This is accomplished, once the microcontroller 74 senses the voltage discrepancy and determines that the discrepancy is sufficiently large that the increased voltage supplied by winding 130 will provide an output voltage V out that is closer to the desired output voltage V out than that provided by the input voltage V in , by having the microcontroller 74 send a gate signal 641 to render the triac Z 1 conductive. As the triac Z 1 is connected between output voltage terminal 56 and the high-voltage end of voltage increment winding 130 of autotransformer 110 , the triac Z 1 will supply an output voltage V out at output terminal 56 that is higher than the input voltage V in at input terminal 40 . The triac Z 1 will be conductive throughout the entirety of the cycle, as illustrated in the third panel for the third AC cycle illustrated in Graph B of FIG. 8 . Graph B illustrates that voltage V, across triac Z 1 is minimal (approximately 1 volt) from beginning to end of the AC cycle, indicating that triac Z 1 is fully conductive throughout that cycle.
Of course the waveform sequence of FIG. 8 is artificial; it would not be expected that the three conditions illustrated would follow one another in consecutive AC cycles. The three panels are present to illustrate three different conditions, not an expected sequence of three successive AC cycles.
If the requisite voltage increment or voltage decrement to be provided by the circuit of FIG. 5A is less than the full increment or decrement available across a given winding of autotransformer 110 , then the microcontroller 74 selects that triac that will provide the output voltage closest to the desired output voltage. If finer increments or decrements are deemed desirable by the designer, then additional triacs and additional corresponding winding taps may be added.
The power driver 65 suggested for the circuit shown in FIG. 5A comprises the circuit 651 within dashed lines in FIG. 5B for triac Z 1 and a discrete identical such circuit for each of the other triacs Z 2 , etc. shown in FIG. 5 A. Each such circuit includes a zero-crossing optically isolated triac driver TD 1 , such as that manufactured by Motorola under item no. MOC3163; the selection of values for resistors R I and R G shown in FIG. 5B is discussed in detail in Motorola Semiconductor Application Note AN982/D. While the power supply circuit illustrated in FIG. 5A could be driven directly by the microcontroller 74 , the use of zero-crossing optically isolated triac drivers is suggested to eliminate current surges and the resulting electromagnetic interference that would result if switching from one voltage to another was attempted while a triac was conducting.
If high voltage or current is to be controlled using the power supply circuit illustrated in FIG. 5A, then back-to-back (reverse parallel SCRs may be substituted for the triacs Z 1 , etc.
Another embodiment of the controlled power supply circuit 52 according to the invention is illustrated in FIG. 6 . An autotransformer 110 is connected between input terminals 40 and 22 ; terminal 22 serving as a common terminal, and input terminal 40 serving as the “live” terminal. Autotransformer 110 is tapped at the central point 166 of its winding by a fixed tap connected to the “high voltage” side of the primary winding 162 of auxiliary transformer 160 . The other “low voltage” terminal of primary winding 162 is connected to an adjustable variable voltage tap 168 that taps the autotransformer winding 110 at a point determined by a servomotor 170 acting in response to power driver 65 of microcontroller 74 (FIG. 2; see also the discussion below of FIGS. 11 and 12 ). Suitable servomotors for low temperature operation are available from Crouzet. The autotransformer 110 may be a standard variac.
The secondary winding 164 of auxiliary transformer 160 is connected in series between input “live” or “hot” terminal 40 and output “live” or “hot” terminal 56 of the power supply circuit of FIG. 6 . Output terminal 60 is a neutral terminal which may be one and the same terminal as input neutral terminal 22 .
If microcontroller 74 provides a control signal that, ultimately converted to analog and applied as an input control signal to servomotor 170 , positions variable tap 168 at centre tap 166 of autotransformer winding 110 , then the output voltage V out will be identical to input voltage V in . It can be seen that, in such an instance, the voltage V P across primary winding 162 of auxiliary transformer 160 is zero, and therefore no augmenting voltage V S across secondary winding 164 of auxiliary transformer 160 will be induced. Consequently, the voltage V out across terminals 56 and 60 will be absolutely identical to voltage V in across input terminals 40 and 22 .
In the event that microcontroller 74 sends a control signal to power driver 65 which, in turn, provides an input control signal 64 to servomotor 170 that positions variable tap 168 at a point lying between terminals 40 and 166 , then the output voltage V out will be higher than the input voltage V in . This result is reflected in Graph C of FIG. 9, which is a plot against time of input voltage V in , output voltage V out , and secondary winding voltage V S of auxiliary transformer 160 . These three voltage wave forms are in phase; by way of example one and a half cycles of the wave forms of each voltage component are illustrated in Graph C of FIG. 9 .
It can be seen that voltage V S , being exactly in phase with voltage V in , augments voltage V in to produce a voltage V out that is the sum of the instantaneous voltages V in and V S at any point in time.
If, on the other hand, the microcontroller 74 provides a control signal to power driver 65 that in turn provides servomotor control signal 64 to the servomotor 170 so as to position variable tap 168 between terminal 166 and terminal 22 , then the output voltage V out across output terminals 56 and 60 will be less than the input voltage V in across input terminals 40 and 22 . This situation is suitable for operation of the power supply circuit of FIG. 6 during the intended “reduced voltage” portion of a diurnal cycle of operation.
For the reduced output voltage mode of operation, voltages V in , V S , and V out are plotted against time over one and a half cycles in curve D, as is the case in curve C, but this time, the voltage V S is 180° out of phase with the voltage V in . Consequently, the output voltage V out is, at any given time, the difference between voltages V in and V S .
FIG. 7A illustrates an embodiment of a controlled power supply circuit utilizing an autotransformer 110 and two pairs of parallel reverse-coupled silicon controlled rectifiers (SCRs) comprising, in one reverse-coupled pair, SCRs S 1 and S 2 , and in the other reverse coupled pair, SCRs S 3 and S 4 . FIG. 7B illustrates a mirror image of the circuit shown in FIG. 7A; its operation will be evident to those skilled in the art in view of the discussion below. Suitable optical coupling or other isolating circuit element (not shown) can be interposed between the microcontroller 74 and the SCR gates 641 , etc. In the following discussion, mention is made of the microcontroller 74 applying control pulses to gates 641 , etc. but it is to be understood that the pulses may be applied indirectly via the isolation device.
The circuit of FIG. 7A is able to supply an output voltage V out from an input voltage V in in with a value of output voltage V out varying between a maximum possible output voltage V max and a minimum value V min . To meet the foregoing objective, autotransformer 110 is divided into three coil segments 112 , 114 and 116 connected in series. The input voltage V in is applied across input terminals 40 and 22 , the “live” input terminal 40 being connected to the point of connection between coils 112 and 114 and the input terminal 22 being essentially a neutral terminal directly connected to the low-voltage point of coil 116 and to output terminal 60 . The voltage V max is available at the connection point 118 , being the voltage across the series-connected coils 112 , 114 , 116 . The minimum voltage V min is available at the connection point 120 between coils 114 and 116 . The output voltage V out is obtained across terminal 56 and neutral terminal 60 . Note that in conformity with standard electrical practice, the neutral terminal 60 may be grounded in circumstances where this would be usual. This remark applies generally to neutral terminals and lines described in this specification.
The input terminal of SCR pair S 1 , S 2 is connected to the high-voltage terminal 118 of autotransformer 110 while the low-voltage terminal 120 is connected to the input of the other SCR pair S 3 , S 4 . The gates of SCRs S 1 through S 4 are operated under the control of gate signals 641 , 642 , 643 and 644 , respectively, corresponding collectively to the control signal 64 illustrated in FIG. 2 . The outputs of both reverse-coupled SCR pairs S 1 through S 4 are in turn connected together and to “live” output terminal 56 .
To understand the operation of the circuit of FIG. 7A, resort may be had to FIGS. 10A, 10 B and 10 C. The graphs of FIGS. 10A, 10 B and 10 C comprise a series of vertically aligned voltage graphs (ordinate) plotted against time (abscissa). FIG. 10A illustrates the situation in which the microcontroller has determined that V out should equal V min . FIG. 10B illustrates the situation in which the microcontroller has determined that V out should equal V max . FIG. 10C illustrates the situation in which the microcontroller has determined that V out should be between V min and V max . In each case the load connected across terminals 56 . 60 is assumed to be resistive.
In the top graph E of FIG. 10A, somewhat more than two complete cycles of voltages V min and V max , appearing as an ordinary sine waves, are illustrated, voltage V min occurring at terminal 120 of FIG. 7 A and voltage V max occurring at terminal 118 of FIG. 7 A. To provide V out equal to V min , the microcontroller 74 applies pulses (directly or indirectly via a suitable isolation device, as mentioned) to gate lines 643 , 644 (indicated in Graphs G and F as pulses P 3 and P 4 , respectively) connected to SCRs S 3 and S 4 , respectively. Note that the microcontroller 74 may supply a constant gate current to gates of SCRs S 3 and S 4 , as in this case timing is not critical and pulsing the gates is not necessary as the goal is for SCRs S 3 and S 4 to each conduct fully for the half cycle in which they are forward-biased. No current is applied to the gates of SCRs S 1 and S 2 . Graph H illustrates the voltage drop across the pair S 3 , S 4 measured from terminal 120 to terminal 56 . The output voltage V out measured across terminals 56 , 60 is shown in Graph I.
In the top graph K of FIG. 10B (which is identical to Graph E of FIG. 10A, but is repeated for ease of reference), somewhat more than two complete cycles of voltages V min and V max , appearing as an ordinary sine waves, are illustrated, voltage V min occurring at terminal 120 of FIG. 7 A and voltage V max occurring at terminal 118 of FIG. 7 A. To provide V out equal to V max , the microcontroller 74 applies pulses to gate lines 641 , 642 (indicated in Graphs M and L as pulses P 1 and P 2 , respectively) connected to SCRs S 1 and S 2 , respectively. Note that the microcontroller 74 may supply a constant gate current to gates of SCRs S 1 and S 2 , as in this case timing is not critical and pulsing the gates is not necessary as the goal is for SCRs S 1 and S 2 to each conduct fully for the half cycle in which they are forward-biased. No current is applied to the gates of SCRs S 3 and S 4 . Graph N illustrates the voltage drop across the pair S 1 , S 2 measured from terminal 118 to terminal 56 . The output voltage V out measured across terminals 56 , 60 is shown in Graph 0 .
In the top graph P of FIG. 10C (which is identical to Graphs E and K of FIGS. 10A and 10B, but is repeated for ease of reference), somewhat more than two complete cycles of voltages V min and V max appearing as an ordinary sine waves, are illustrated, voltage V min occurring at terminal 120 of FIG. 7 A and voltage V max occurring at terminal 118 of FIG. 7 A. To provide V out between V min and V max , the microcontroller 74 applies pulses to gate lines 641 , 642 , 643 , and 644 (indicated in Graphs T, S, R, and Q as pulses P 1 , P 2 , P 3 , and P 4 , respectively) connected to SCRs S 1 , S 2 , S 3 , and S 4 , respectively. Note that the microcontroller 74 does not supply a constant gate current to gates of the SCRs S 1 , S 2 , S 3 , and S 4 , as in this case timing is critical and pulsing the gates is necessary. Graph U illustrates the voltage drop across the pair S 3 , S 4 measured from terminal 120 to terminal 56 . Graph V illustrates the voltage drop across the pair S 1 , S 2 measured from terminal 118 to terminal 56 . The output voltage V out measured across terminals 56 , 60 is shown in Graph W.
In the following discussion the timing of the application of gate pulses to SCRs S 1 , S 2 , S 3 , and S 4 is given by the “phase angle”, which refers to the angle (one complete AC cycle being 360° ) at which gate pulses are applied relative to the AC waveform of the voltage across the SCR in question. In particular, in the graphs shown in FIG. 10C, phase angles are measured relative to the rising zero crossing of the voltages V min and V max shown in Graph P. Dashed vertical lines are used in FIG. 10C to shown the correspondence of phases angles between graphs.
The pattern of pulses P 1 , P 2 , P 3 , and P 4 , applied by microcontroller 74 to the gates of SCRs S 1 , S 2 , S 3 , and S 4 , respectively, begins with pulse P 4 being applied to SCR S 4 at phase angle 0° causing SCR S 4 to conduct. At phase angle α, pulse P 2 is applied to SCR S 2 driving SCR S 2 into conduction, which reverse-biases SCR S 4 causing it to cease to conduct. At a phase angle of 180°, pulse P 3 is applied to SCR S 3 causing SCR S 3 to conduct. At a phase angle of 180°+α, pulse P 1 is applied to SCR S 1 driving SCR S 1 into conduction, which reverse-biases SCR S 3 causing it to cease to conduct.
It is not critical that the pulses last until the next pulse in the series is applied so long as the pulses P 4 and P 3 commence at phase angles 0° and 180° degrees, respectively, and pulses P 2 and P 1 commence at phase angles α and 180°+α, respectively.
In order to avoid transient effects that might be caused by voltage surges when the voltage V out shifts from the V max value to the V min value or vice versa, a smoothing capacitor 70 or other suitable output smoothing filter across output terminals 56 and 60 (see FIG. 2) is typically provided to generate a smoother final output voltage V out , as illustrated in Graph X of FIG. 10 C. The smoothing capacitor 70 has not been illustrated in FIG. 7A but will typically be present. The resulting smoothed final output voltage V out , illustrated in Graph X will have an RMS value between V min and V max determined by the value of phase angle α.
Considering FIGS. 10A, 10 B, and 10 C together, it can be seen that if it is desired that the output voltage V out be an absolute minimum, then one would choose the phase angle α to be 180° (in effect SCR pair S 1 , S 2 would not conduct at all). Equally, if it is desired that the output voltage V out be equal to the maximum value V max available from the circuit of FIG. 7A, then the phase angle α is chosen to be 0° (in effect SCR pair S 3 , S 4 would not conduct at all) . If the phase angle α is chosen to be at a value between 0° and 180°, then the output voltage V out is necessarily somewhere between V max and V min , Graph W illustrating the exemplary choice of α between 90° and 180°, thereby providing an output voltage V out that is between the minimum value V min and maximum value V max on an RMS basis. Note that to obtain this control over the output voltage, the microcontroller 74 does not have to provide any voltage value signal; rather, it provides a timing signal that controls the timing of the gate pulses P 1 , P 2 , P 3 , P 4 . Accordingly, the time control signal provided by microcontroller 74 is translated into a voltage control signal as the result of the gated operation of the SCRS S 1 , S 2 , S 3 and S 4 .
The cycle of pulses P 4 , P 2 , P 3 , and P 1 , continues recurring indefinitely every 360° of phase angle as long as power is required by the load. For example, in FIG. 10C the cycle of pulses P 4 , P 2 , P 3 , and P 1 recurs at phase angles of 360°, 360°+α, 540°, and 540°+α (0°+360°, α+360°, 180°+360°, and 180°+α+360°). The microcontroller 74 , when necessary, varies the phase angle α to adjust the voltage V out , but the cycle of pulses continues until voltage V out is no longer required.
FIG. 11 illustrates one possible power driver for use as the power driver 65 in FIG. 2, for use in conjunction with the FIG. 6 output power circuit.
In FIG. 11, the servomotor 170 has its neutral terminal connected to input neutral terminal 46 . The servomotor 170 is provided with clockwise drive in put terminal 50 and a counterclockwise drive input terminal 54 . “Live” or “hot” input terminal 44 provides current to input terminal 50 or input terminal 54 , depending upon whether switch 66 connected between input terminal 44 and clockwise drive terminal 50 is closed, or whether switch 68 connected between input hot terminal 44 and counterclockwise drive power terminal 54 is closed. A startup/running capacitor 67 connected across the two drive terminals 50 , 54 tends to prevent “stuttering” of the servomotor 170 .
Switch 66 closes when its associated actuating relay coil 72 passes current. Equally, switch 68 closes with its associated actuating relay coil 76 passes current.
Relay coil 72 is driven by power transistor 75 , and relay coil 76 is driven by power transistor 77 . The emitters of the two transistors 75 , 77 may be connected to a common terminal 73 . The gates of transistors 75 , 77 are driven via drive signal terminals 79 , 81 respectively. The microcontroller 74 provides a square-wave-type drive signal via a digital/analog converter to the selected gate drive terminal 79 , 81 depending upon whether clockwise or counterclockwise rotation of servomotor 170 is required.
In operation, if the microcontroller 74 detects that the output voltage differs by more than a threshold differential from a particular target output voltage value for the time being established, then the microcontroller 74 will provide an appropriate drive signal (typically a limited DC voltage) to either the gate terminal 79 or the gate terminal 81 , depending upon whether the voltage adjustment required necessitates a clockwise or counterclockwise rotary movement of the armature of servomotor 170 . The signal applied to gate terminal 79 or 81 , as the case may be, is continued until the microcontroller 74 senses that the actual output load voltage is equal to the interim target voltage (within a tolerance or threshold) and at that time, the microcontroller 74 discontinues sending a control signal to gate terminal 79 or 81 , as the case may be.
The manner in which servomotor 170 supplies control signal 64 to power supply circuit 52 has already been described with reference to FIG. 6 .
While FIG. 11 illustrates a circuit suitable for driving the power supply circuit of FIG. 6, essentially similar drive principles could be established for other types of power supply circuits and power drivers suitable for use therewith.
FIG. 12 is a circuit diagram of an alternative power driver circuit again for use with the servomotor-controlled power supply circuit of FIG. 6 . In this case, the servomotor 170 is shown connected in exactly the same way as the servomotor 170 was connected in FIG. 11, with the exception that switches 66 and 68 have been replaced by triacs 53 and 55 respectively. Accordingly, power is supplied to clockwise drive power terminal 50 if triac 53 is conducting, and power is supplied to counterclockwise power drive terminal 54 if triac 55 is conducting. Triac 53 is provided with a gate 57 to which the microcontroller 74 will selectably cause to be sent a suitable DC control signal (using appropriate digital/analog conversion) thereby forcing a clockwise rotary motion of the armature of servomotor 170 . Similarly, if counterclockwise rotary movement of the servomotor armature were required, then the microcontroller 74 would cause to be applied the appropriate DC gate control signal to gate 59 of triac 55 , thereby supplying power to counterclockwise power drive terminal 54 .
Alternative circuits suitable for driving the power supply circuits of FIGS. 5A, 6 and 7 A (or 7 B) can be readily devised using standard circuit design principles by analogy to the circuits of FIGS. 5B, 11 and 12 provided by way of exemplification.
EXAMPLE
The example to be given refers to the circuit of FIG. 6 . Four different operating conditions will be examined; viz a first operating condition in which the output voltage supplied to the load is to be equal to the input voltage, a second in which the output voltage supplied to the load is to be greater than the input voltage, and a third in which the output voltage supplied to the load is to be less than the input voltage. In a variant of the third condition, a fourth condition is examined in which it is desired that the output voltage be less than rated full-power voltage. In all three cases to be examined by way of example, the output voltage V out is to be 240 volts, and rated load current is to be 10 amperes supplied to a load of 24 ohms.
First operating condition: V out =V in
The output voltage V out is to be equal to the input voltage V in at a value of 240 volts. In this case, the variable tap 168 on autotransformer 110 will be positioned (under the control of servomotor 170 in turn responding to the power driver 65 and microcontroller 74 ) to be coincident with centre point 166 of the autotransformer winding 110 . In such case, the voltage drop across the auxiliary transformer 160 is zero and, accordingly, rated load current of 10 amperes will flow to the load connected across output terminals 56 and 60 to supply 2,400 watts to the load.
Second operating condition: V out >V in
Now consider a second case in which the output voltage is to be higher than the input voltage. Assume that, as was the case previously, the output load is 24 ohms and it is desired to deliver 2,400 watts to the load at an output voltage V out of 240 volts, but the input voltage V in is only 220 volts. In such case, it is necessary that the voltage V S across the secondary winding 164 of auxiliary transformer 160 contribute an additional 20 volts to the output voltage. This result is accomplished by positioning the variable tap 168 at the correct position along autotransformer winding 110 ; the correct position must necessarily be located between terminals 40 and 166 . The analysis is as follows:
As 10 amperes must be flowing through auxiliary transformer secondary winding 164 , then voltage V P and current I P across and through primary winding 162 of auxiliary transformer 160 can be computed. If we assume that the turns ratio Γ of auxiliary transformer 160 is 2.5, then primary winding current I P is given as follows:
I P =I S /Γ=10/2.5=4 amperes.
The voltage V P required to deliver the additional 20 volt component V S provided by secondary winding 164 is given as follows:
V P =( V S ) (Γ)=(20) (2.5)=50 volts.
We require output power P L =2,400 watts to be delivered to the load at an output voltage of 240 volts in this example, and the input voltage is only 220 volts. We know that the input current I in is given by:
I in =P L /V in in=2400/220=10.9 amperes.
Of this 10.9 amperes, 10 amperes of course flows through secondary winding 164 of auxiliary transformer 162 to the load. Accordingly, 0.9 amperes (approximately) flows through autotransformer 110 . Since it has already been determined above that in the primary winding 162 of auxiliary transformer 160 the voltage is 50 volts and the current is 4 amperes, it follows that the voltage contribution for transformer primary winding 162 must be a 50-volt contribution across that portion of the autotransformer winding 110 lying between the position of variable tap 168 and centerpoint 166 . Further, since the current flow of 4 amperes through the aforementioned portion of autotransformer winding 110 is in opposition to the 0.9 amperes net current flow through the autotransformer 110 , it follows that the net current in the portion of autotransformer winding 110 lying between variable tap 168 and fixed tap 166 will be 3.1 amperes (4.0 amperes less 0.9 amperes). Since the total voltage drop across autotransformer winding 110 is 220 volts, it follows that midpoint tap 166 is at a voltage of 110 volts. As the voltage drop between fixed tap 166 and terminal 40 must also be 110 volts, it follows that variable tap 168 is positioned in the upper portion of winding 110 (as viewed schematically in FIG. 6 ) at a point displaced 5/11 of the winding distance along winding 110 from centre tap 166 in the direction of terminal 40 , in order to provide 50 volts across primary winding 162 of auxiliary transformer 160 .
Accordingly, all parameters have been identified that are necessary to establish the proper position of adjustable tap 168 , and from this information and knowing the relationship between the input signal 64 and the output position of tap 168 provided by servomotor 170 , the necessary value of servomotor control signal 64 can be computed. Given this value 64 and the known characteristics of the power driver 65 , the requisite control signal from microcontroller 74 to power driver 65 can equally be computed. These values, of course, will vary depending upon the electrical characteristics of servomotor 170 and the circuit characteristics of power driver 65 .
Third operating condition: V out <V in
In the third case, the input voltage is higher across input terminals 40 and 22 . Assume that the input voltage is 260 volts whilst the output voltage is required to remain the same as before, namely 240 volts, to supply 10 amperes of current to a presumed output load of 24 ohms.
In this case, it can be computed that as the output power remains the same at 2,400 watts, the input current at an input voltage of 260 volts, will be about 9.2 amperes. Accordingly, there must be a net flow of current across autotransformer 110 of 0.8 amperes from terminal 22 to terminal 40 . Again, the voltage differential to be supplied by secondary winding 164 of auxiliary transformer 160 is 20 volts, but this time the voltage to be supplied by winding 164 is of polarity opposite to the polarity established for the second case discussed above. The current draw computed in the same way as previously will be 4 amperes through the primary winding 162 of auxiliary transformer 160 ; the combined current flow through the portion of autotransformer 110 between centre tap 166 and variable tap 168 (which, in this third case, will necessarily be positioned between neutral terminal 22 and center tap 166 along the lower portion of autotransformer winding 110 as viewed schematically in FIG. 6) will be a net 3.2 amperes.
The computations proceed as in the second case to establish the lengthwise physical positioning of variable tap 168 along the “lower” half winding of autotransformer 110 . Knowing the characteristics of servomotor 170 and power driver 65 , the requisite control signals can be established to be provided by microcontroller 74 and power driver 65 respectively.
Fourth operating condition: V out <V in ; V out <rated full-power output voltage
Assume that input voltage is 240 volts and that load power is to be reduced by reducing the output voltage V out to 200 volts. In such case, the 24-ohm load will be provided with output power of 1666 watts and will require a current of 8.33 amperes. The voltage differential to be supplied by secondary winding 164 of auxiliary transformer 160 is 40 volts, so at a 2.5 turns ratio, a voltage differential of 100 volts must be supplied by the primary winding 162 of auxiliary transformer 160 (the voltage will be in opposition to the input voltage V in ). The current draw computed in the same way as previously (8.33/2.5) will be 3.33 amperes through the primary winding 162 of auxiliary transformer 160 . The combined current flow through the portion of autotransformer 110 between centre tap 166 and variable tap 168 (which, in this fourth case, will necessarily be positioned between neutral terminal 22 and centre tap 166 along the lower portion of autotransformer winding 110 as viewed schematically in FIG. 6) will be a net 1.39 amperes, 6.96 amperes being supplied by the input to the autotransformer 110 .
While a number of embodiments of various circuit configurations in conformity with the invention have been described and illustrated, the invention is not to be limited to those specific embodiments, but embraces equivalents within the skill of circuit designers. The scope of the invention is as set forth in the appended claims.
For simplification of description, a number of assumptions and omissions have been made in this specification. For example, in the discussion of transformer or autotransformer current and voltage values, no account has been taken of internal losses; transformer efficiency has been assumed to be 100%, which is not possible, but need not be specially considered in the context of any given point under discussion. Such assumptions and omissions are conventional in discussion of electric circuits of the sort described, and will be recognized as such by those skilled in electric circuit design.
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The invention is a load voltage and power control and supply system for the supply of power to a load for which, over particular periods of time, usually on a daily basis, it is desired to reduce power. The invention has particular application to street lighting systems in which, for a period of several hours during the night (when traffic is minimal and many people are asleep), the luminaires of the lighting system can operate at reduced power. The power control system is able to act as a voltage stabilizer as well as a controlled power reduction system. The power control system may operate the bank of spaced luminaires from a single control location. Moderately reduced power (say a 30% reduction in power) supplied to luminaires does not noticeably diminish the adequacy of the illumination provided. Further, the power control system reduces power in stepwise decrements each of which reduces power by a small amount insufficient to diminish noticeably the ambient illumination.
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FIELD OF THE INVENTION
This invention relates to a method of deinking waste paper for reclamation thereof. More particularly, the invention relates to a method of deinking waste paper such as newspapers or magazines using a specific fatty acid polyoxyalkylene ester as a deinking agent in the known floatation method to provide deinked pulp having a high degree of whiteness and low residual ink droplet number.
DESCRIPTION OF THE PRIOR ART
Waste paper such as newspapers or magazines have been reclaimed by disintegrating the waste paper to pulp fibers and then removing printing ink components such as carbons or vehicles from the pulp fibers to recover the pulp fibers for reuse as paper making material. The reclamation of waste paper becomes more important on account of shortage of wood resources and rise in their prices, and there is a strong demand for a higher performance deinking agent since it becomes more difficult to deink the recent waste paper on account of changes in the printing techniques, printing systems and printing ink compositions.
The floation method has been known as a representative of the deinking methods of waste paper for its reclamation. According to the floation method, the waste paper is disintegrated with an alkali in water to provide an aqueous slurry of pulp fibers, a deinking agent is added thereto to remove the ink components from the waste paper and allow the ink compositions to coagulate, blowing the air into the slurry so that it foams and the ink compositions adhere to the foam, and then the foam is removed from the slurry together with the ink compositions to leave deinked pulp fibers. The resultant pulp fibers are bleached for reuse as paper making material.
A variety of surfactants have been used as a deinking agent in the floation method, and a higher fatty acid soap such as stearic acid soap is a representative. The higher fatty acid soap has a high performance for removing ink compositions from waste paper. However, the higher fatty acid soap is not sufficiently foamable so that the coagulated and floated ink compositions are incompletely removed, and thus the recovered pulp fibers have still a many number of ink spots therein. There is also a tendency that the released ink compositions deposit on the deinking device used. Moreover, it is necessary to use the higher fatty acid soap in a large amount to obtain intended deinking results, and accordingly the deinking cost is high.
In order to solve these problems, there have been recently proposed a number of deinking agents other than the higher fatty acid soap, among which are anionic surfactants such as sodium alkylbenzenesulfonates, higher alcohol sulfate salts, alpha-olefin sulfonates or dialkyl sulfosuccinates; or nonionic surfactants such as higher alcohols, alkylphenols, ethylene oxide and/or propylene adducts to higher alcohols or alkylphenols. Very recently, there have been proposed a deinking agent containing alkylene oxide adducts to higher fatty acids which is featured by the presence of a carboxyl group residual bonded to a polyoxyalkylene group, as disclosed in Japanese Patent Publication No. 61711/1987, Japanese Patent Application Laid-open No. 182489/1988 and Japanese Patent Publication No. 11756/1989 among others.
The above mentioned agents are improved in many respects compared with the higher fatty acid soap, however, the ink removal performance when used in the floation method is not satisfactory.
BRIEF SUMMARY OF THE INVENTION
It is, therefore, an object of the invention to provide a method of deinking waste paper such as newspapers or magazines using a specific deinking agent in the known floatation method to provide deinked pulp having a high degree of whiteness and low residual ink droplet number.
The invention provides a method of deinking waste paper for reclamation thereof, which comprises disintegrating waste paper with an alkali in water in the presence of a fatty acid polyoxyalkylene ester having the formula
R--COO(PO)x(AO)y(PO)z--H
wherein R is an alkyl or alkenyl of 7-21 carbons, PO is an oxypropylene group, AO is an oxyethylene group, or a mixed oxyalkylene group composed of an oxyethylene group and at least one oxyalkylene group selected from the group consisting of an oxypropylene group and an oxybutylene group, and x is a numeral of 1-20, y is a numeral of 1-50, and z is a numeral of 1-50, as a deinking agent.
DETAILED DESCRIPTION
The above fatty acid polyoxyalkylene ester used in the invention as a deinking agent is structurally featured by that it has oxypropylene groups bonded to the carboxyl group residual of the fatty acid and propylene glycol residual at the end of the molecule.
Since the deinking agent used in the method of the invention contains the above fatty acid polyoxyalkylene ester as a deinking agent which is well-balanced in dispersibility and coagulating ability of ink compositions, and thus the use of the deinking agent according to the invention in the floatation method provides deinked pulp having a high degree of whiteness and low residual ink droplet number.
The fatty acid polyoxyalkylene ester having an average molecular weight preferably of 800-8000, more preferably 1000-2000, most preferably 1700-2000, is preferred since such an ester has especially eminent deinking effects.
A further feature of the fatty acid polyoxyalkylene ester is that it is liquid at normal temperatures, and can be added as it is to a disintegrator when waste paper is disintegrated in water so that the energy cost for deinking treatment is greatly reduced.
The fatty acid polyoxyalkylene ester may be produced by a known method in which, as fatty acid components, there may be used, for example, caprylic acid, capric acid, lauric acid, oleic acid, myristic acid, palmitic acid or stearic acid. These fatty acids may be used singly or as a mixture. In particular, stearic acid, palmitic acid or oleic acid is preferred on account of high deinking performance.
In the above formula, AO is an oxyethylene group, or a mixed oxyalkylene group composed of an oxyethylene group and at least one oxyalkylene group selected from the group consisting of an oxypropylene group and an oxybutylene group. Thus, the AO may be an oxyethylene group, oxyethylene/oxypropylene group, oxyethylene/oxybutylene group, oxyethylene/oxypropylene/oxybutylene group or an oxybutylene group. These oxyalkylene groups may be in the form of random copolymers or block copolymers.
According to the method of the invention, the fatty acid polyoxyalkylene ester is used in the stage of disintegrating waste paper in water with an alkali such as sodium hydroxide usually in an amount of 0.2-1.0% by weight based on the waste paper, although not limited to the exemplified.
The method of the invention has an important feature in that the deinking agent can be used as a one component agent. However, the agent may be used in conjunction with any known deinking agent such as anionic surfactants or nonionic surfactants, for example, a higher alcohol, a higher alcohol sulfate salt, a sulfate salt of ethylene oxide adducts to higher alcohols or alkylphenols.
As above set forth, the method of the invention uses such a specific fatty acid polyoxyalkylene ester as a deinking agent in the floatation method for waste paper reclamation, and thus the method provides deinked pulp having a high degree of whiteness and low residual ink droplet number. In addition, the deinking agent used is a one component liquid agent so that it can be used easily and reduces the energy required in the floatation method in the deinking process.
The invention will be described in more detail with reference to examples, however, the invention is not limited to the examples.
EXAMPLES
Eighty percent by weight of waste newspapers (offset/relief ratio: 6/4) and 20% by weight of waste leaflets were cut into pieces and placed in a bench disintegrator (JIS P-8209), to which were then added 1.5% by weight of sodium hydroxide, 3.5% by weight of No. 3 sodium silicate, 1.0% by weight of a 30% aqueous solution of hydrogen peroxide and 0.3% by weight of a deinking agent indicated in Table 1, each based on the weight of the waste paper, and then warm water so that the resultant aqueous slurry contained the waste paper in an amount of 10% by weight. The waste paper was then disintegrated at 55° C. for 20 minutes. The resultant pulp slurry was diluted to a pulp concentration of 1% by weight, and then the floatation treatment was carried out at 30° C. for 10 minutes with the use of a testing floatator.
The resultant pulp slurry was formed into a sheet having a weight of 150 g/m 2 using a standard type sheeting machine (JIS P-8209). The whiteness of the sheet was measured with a Hunter whiteness meter according to JIS P-8123. The residual ink droplet number was measured with an image analyzer (×100). The results are summarized in Table 1.
TABLE 1__________________________________________________________________________ Whiteness Residual Ink Average MolecularDeinking Agent (%) Droplet Number Weight__________________________________________________________________________Examples1 C.sub.15 H.sub.31 COO(PO).sub.7 (EO).sub.15 (PO).sub.5 (EO).sub.15 (PO).sub.7 H 55.8 12 26782 C.sub.15 H.sub.31 COO(PO).sub.5 [(EO).sub.25 (EO).sub.5 ](PO).sub.5 55.2 11 22963 C.sub.17 H.sub.35 COO(PO).sub.10 (EO).sub.30 (PO).sub.10 H 56.6 14 27644 C.sub.17 H.sub.35 COO(PO).sub.10 [(EO).sub.30 (PO).sub.5 ](PO).sub.5 56.3 11 27645 C.sub.17 H.sub.33 COO(PO).sub.6 (EO).sub.40 (PO).sub.5 H 56.0 13 25066 C.sub.17 H.sub.33 COO(PO).sub.10 [(EO).sub.30 (PO).sub.5 ](PO).sub.20 55.8 15 36327 C.sub.17 H.sub.35 COO(PO).sub.7 (EO).sub.25 (PO).sub.6 H 57.3 8 19648 C.sub.17 H.sub.35 COO(PO).sub.5 (EO).sub.15 (PO).sub.12 H 57.6 7 19309 C.sub.15 H.sub.31 COO(PO).sub.10 (EO).sub.14 (PO).sub.10 H 57.4 7 195610 C.sub.15 H.sub.31 COO(PO).sub.3 (EO).sub.10 (PO).sub.15 H 57.1 6 174011 C.sub. 15 H.sub.31 COO(PO).sub.10 (EO).sub.5 (PO).sub.15 H 58.0 6 1926Comparative Examples1 C.sub.17 H.sub.35 COO(EO).sub.5 (PO).sub.10 (EO).sub.20 H 50.1 39 19642 C.sub.17 H.sub.33 COO(EO).sub.20 (PO).sub.10 H 51.7 37 17423 C.sub.15 H.sub.31 COO(EO).sub.15 H 50.3 33 9164 C.sub.15 H.sub.31 COO(PO).sub.2 H 50.2 40 3725 C.sub.17 H.sub.35 COO(PO).sub.20 (EO).sub.250 (PO).sub.20 H 50.3 42 136046 C.sub.15 H.sub.31 COO(PO).sub.20 (EO).sub.270 (PO).sub.20 H 50.0 38 144567 C.sub.17 H.sub.35 COO[(EO).sub.6 (PO).sub.15 ]H 51.1 35 1418__________________________________________________________________________ NOTES: Oxyalkylenes in the brackets are in the form of random copolymers.
As seen in Table 1, the method of the invention provides deinked pulp having a higher degree of whiteness and lower residual ink droplet number than a method wherein a fatty acid polyoxyalylene ester which has oxyethylene groups bonded to the carboxyl residual of fatty acid is used as a deinking agent, and even than a method wherein a fatty acid polyoxyalylene ester which has oxypropylene groups bonded to the carboxyl residual of fatty acid, but has no such a structure as contains the AO group between the oxypropylene groups bonded to the carboxyl residual of fatty acid and the oxypropylene group at the end of the molecule.
It is also understood that the use of fatty acid polyoxyalylene ester which has an average molecular weight of 1000-2000 provides the best results.
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A method of deinking waste paper for reclamation thereof, which comprises disintegrating waste paper with an alkali in water in the presence of a fatty acid polyoxyalkylene ester having the formula
R--COO(PO)x(AO)y(PO)z--H
wherein R is an alkyl or alkenyl of 7-21 carbons, PO is an oxypropylene group, AO is an oxyethylene group, or a mixed oxyalkylene group composed of an oxyethylene group and at least one oxyalkylene group selected from the group consisting of an oxypropylene group and an oxybutylene group, and x is a numeral of 1-20, y is a numeral of 1-50, and z is a numeral of 1-50, as a deinking agent.
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FIELD OF THE INVENTION
The present invention relates to a method for detecting the presence and determining the quantity of contaminants on surfaces. More particularly, the invention relates to a method for rapidly determining the total microbial contamination or for determining the presence and quantity of specific microbial or chemical contaminant present on a wide variety of surfaces including surfaces of meat carcasses or other food, surfaces of equipment, surfaces where food is being processed or prepared, and surfaces of equipment, gloves and materials in medical situations. Furthermore, the invention relates to a method for determining the total microbial or specific microbial or chemical contamination by bioluminescence or chemiluminescence.
BACKGROUND OF THE INVENTION
Microbial contamination of surfaces is a significant cause of morbidity and mortality. Rapid and routine procedures for quantitative determination of bacteria present on surfaces is frequently of vital importance, particularly in food processing and in hospitals. Food poisoning is often a result of microbial contamination of meat or food that occurs during processing. Contamination can be spread through contact of food with surfaces. In addition, spread of disease in hospitals and other facilities often occurs as a result of passage of infectious microbes on the surface of clothes or equipment.
Key feature of these applications is the requirement for rapid testing within minutes, a method that will overcome the potential contaminants from a variety of surfaces, a requirement for no cross-over in the results from one test to a second, and a need for both general and specific testing for microbes, that is, the ability to test for contamination by both total microbial counts and the ability to test for the presence of specific microbes.
Various methods have been utilized to measure microbial contamination on surfaces. Traditional procedures for assaying bacteria on surfaces are based on swabbing the surface followed by a culture of the swab for 24 to 48 hours in or on media that supports the growth of microbial species. The cultures are observed manually or with automated instrumentation to determine the number of colonies that have formed as an indicator of the number of microbes initially present on the surface. The disadvantages of this methodology are long assay times, requirements for specially trained personnel, and possible inadequate identification of the presence of certain potentially pathogenic microbes whose growth is not supported by the specific media or environment. In particular, it may be difficult to detect fungal contamination by this method. In addition, in many of the potential applications, the method does not give results in the time frame required for effective response.
Luminescent reactions have been utilized in various forms to detect bacteria in fluids and in processed materials. In particular, bioluminescent reactions based on the reaction of adenosine triphosphate (ATP) with luciferin in the presence of the enzyme luciferase to produce light, the "firefly" reaction have been utilized. Since ATP is present in all living cells including all microbial cells, this method can be used in a rapid assay to obtain a quantitative estimate of the number of living cells in a sample. Early discourses on the nature of the reaction, the history of its discovery, and its general area of applicability are provided by E. N. Harvey (1957), A History of Luminescence: From the Earliest Times Until 1900, Amer. Phil. Soc., Philadelphia Pa. and W. D. McElroy and B. L. Strehler (1949) Arch. Biochem.Biophys. 22:420-433. Alternatively, chemiluminescent detection by isoluminol or similar compounds has been used. This method is based on the detection of iron-containing substances in microbes.
Test procedures exemplifying the use of bioluminescent reactions for bacterial determinations and, specialized instrumentation for measurement of the associated light emission, are known and have been disclosed. Plakas (U.S. Pat. Nos. 4,013,418, 4,144,134, and 4,283,490) teaches a bioluminescent assay for the detection of bacteria in a sample including the steps of lysing non-bacterial cells, effecting filtration by positive pressure, washing, lysing bacterial cells and detecting ATP released with a luciferin/luciferase/Mg2+ reagent. This art in this patent does not deal with the specific problems associated with collection of material from a surface or with the detection of specific bacteria. No issue of the timing is mentioned and the invention as disclosed would require significant time.
Chappelle in U.S. Pat. No. 4,385,113 discloses a method for detection of bacteria in water based on bioluminescence. This test requires several hours to perform and is specifically addressed to the detection of total bacterial content in water.
Miller (PCT application US88/00852) discusses a similar assay for use with urine samples, but does not discuss the issues of collection from a surface and the assay timing is not specifically set forward in this application. Further, no method for detection of specific bacteria is elucidated.
Clendenning in his U.S. Pat. No. 3,933,592 discusses a method for bioluminescent detection of microbial contamination and in the examples refers to performing the procedure in less than 2 minutes. The procedure does not involve pre-treatment phases and the removal of somatic cell ATP.
AEgidius (U.S. Pat. No. 5,258,285) discloses a method for detection of bacterial concentration in a sample that utilizes a filtration step, a washing step to remove extraneous material including somatic cell ATP, establishing an extraction chamber in which the bacterial ATP is extracted, then transferring the material to a measuring chamber in which luciferin/luciferase/Mg2+ is added and the reaction measured. This method does not mention time. In addition, it utilizes separate chambers for washing, extracting the bacterial ATP, and measuring the reaction. This may potentially result in decreased sensitivity due to loss of the material in the process of transferring the solution from chamber to chamber. Further, the method does not describe a means of collecting a sample from a surface.
Detection of bacteria on surfaces poses additional issues not addressed in these previous methods. First and foremost is the method for collecting a sample to be compatible with these test devices and materials. The method must effectively retrieve the bacteria from the surface and result in a liquid suspension of the microbes.
A second issue of main concern is that surfaces being monitored often are contaminated with materials that may interfere with the detection of the microbes. One main interfering material that can be present on surfaces is somatic cells either from the food itself and including both animal and plant cells, or from the hands of an individual in contact with the surface. Since all living organisms including somatic cells contain ATP, the presence of these cells can mask or alter the reading obtained.
An additional source of interfering substances are those that interfere with the light producing reaction itself. These substances include a wide range of chemicals such as chlorine, oxidizing agents, free ATP, heavy metals, and other chemicals. As some of these chemicals are used for disinfecting of a surface, it is obvious that a reliable method for analyzing microbial contamination must include a means of eliminating these substances from the sample.
It is a further requirement in many cases in the food processing and hospital applications that the method for monitoring for microbial contamination of surfaces be rapid. For example, in the processing of beef carcasses, the carcasses are processed on a line and any testing of the material for microbial contamination must be performed within the time frame required for the carcass to move to further processing.
Previously disclosed luminescence based methodologies for microbial detection have not included any means for processing a sample from a surface and making a liquid suspension for testing. Further, the processes have required multiple devices or chambers for containment, filtration, and measurement of the reaction. Finally, the processes have not incorporated a disposable device that allows for minimizing cross-contaminations. Finally, in those assays for detecting specifically microbial ATP and other specific surface contaminants, previously disclosed inventions have relatively long time frames which are not consistent with on-line processing, quality control, and immediate verification of results.
SUMMARY OF THE INVENTION
The present invention is a method and device for determining the presence and/or concentration of total microbial concentration or the presence and/or concentration of a specific target analyte derived from a surface. The method firstly comprises collecting a surface sample by wiping a circumscribed area of a surface in a prescribed fashion using a collection apparatus means comprised of an absorbent or adsorbent material. The said collection apparatus means is placed into a container containing a fluid and agitated to release the surface contaminants from the collection apparatus means into the fluid. The collection apparatus means can be in the form of a sponge or a swab and the container can be a bag, tube, or small cup. An aliquot of the fluid phase is subsequently transferred to a disposable test device comprised of a translucent hollow cylinder, open on the top and having a porous filter attached on the bottom. The fluid phase is filtered through the disposable test device by applying either positive or negative pressure resulting in retention of microbes or target analytes on the surface of the filter. The filtration process results in the concentration of analyte and the removal of any interfering substances from the collectate prior to testing, such as inhibitors or any nonspecific materials to maximize test sensitivity and specificity. The filter retentate can be washed by adding appropriate wash solutions and reapplying appropriate pressure to three the fluid phase through the filter. Another feature of the present invention is that the retentate captured on the filter of the disposable test device can be assayed by a chemiluminescent or bioluminescent test method. Said final step of said test method comprising addition of a luminescent substrate to the retentate resulting in a chemiluminescent reaction and measuring the light output from said chemiluminescent reaction by using a photometer that accommodates the disposable device in a manner which allows its precise and reproducible positioning with respect to the surface of the photosensor and which precludes any possible loss of the final reaction mixture during and after the measurement cycle.
The present invention allows for a surface contaminant to be identified and/or concentration determined in less than 1 hour from time of collection to end result, and generally in less than 5 minutes.
More specifically, the present invention comprises a method for performing chemiluminescent assays such as bioluminescent assays for ATP, chemiluminescent immunoassay or DNA probe assays. One embodiment of the present invention is a method for determining the total microbial contamination comprising the steps of:
a) collecting a surface sample with a collection apparatus means and
b) agitating said collection apparatus means with a fluid phase to dislodge the surface contaminants into a fluid phase, said fluid phase the becoming the collectate and
c) placing an aliquot of said collectate into a disposable test device, and
d) adding a washing/lysing reagent that lyses any somatic cells present in the aliquot and
e) applying positive pressure to the top of the disposable test device or negative pressure to the bottom of the disposable test device to eliminate the liquid phase containing free ATP and any chemical inhibitors as well as concentrating the bacteria at the interface, and
f) adding a bacterial lysing reagent that perforates the bacterial cell walls allowing the release of microbial ATP, and
g) adding ATP free luciferin and luciferase reagent, and
h) determining the amount of ATP present by measuring the light emitted through translucent sides of said disposable test device.
The choice of collection fluids are well known to those skilled in the art. Generally the fluid is comprised of a detergent, salt, or buffer or any combination thereof that maintains the integrity of the microbial cell walls. A fluid consisting of 0.15M sodium chloride containing 0.5% Tween 20 detergent is one such choice. It is possible to use other formulations including phosphate or HEPES buffered saline and other detergents including zwitterionic detergents and non-ionic detergents.
It will be obvious to a person skilled in the art that mixing of reactant could be achieved in any of the steps through the use of a micropipette. The detection method of this invention specifically allows for both the concentration of analyte and any resulting chemiluminescent reaction caused by the presence of said analyte to occur within the chamber of the disposable test device. An added feature of the disposable test device is that the diameter of the filter is from 0.5 to 2.0 cm, preferably about 1.0 cm, so that the volume of bioluminescent or chemiluminescent substrate solution is minimized to maximize signal output to the photodetector means. The final volume of the substrate should be between 20 μl to 1000 μl, most preferably about 60 μl to 100 μl. The disposable test device can be inserted into a complementary device comprising a larger (liquid tight) at least two component chamber that can house the disposable test device and through which a volume of collectate greater than 500 μl can pass through the filter under positive or negative pressure and retain the microbes or the analytes of interest onto the surface of the filter. For example, the disposable test device can be inserted into the lower chamber of the two component device, said lower chamber having an outflow for the filtrate to which is attached a removable upper chamber of the two component device. The said upper chamber comprising a liquid tight seal to said lower compartment and having an intake valve. Said intake valve can be configured for a complementary luer tip fitting for attachment of a luer tipped syringe. Said syringe may include at least one series of prefilter(s) to remove any larger debris from entering the filter of the disposable test device. At completion of passing the collectate through the filter of the disposable test device, the two component device can be opened, and the disposable test device physically removed. Said disposable test device now containing the retentate from a large volume of collectate (i.e. 50 ml). The filtration of said large volume of collectate enables increased sensitivity for analyte detection of the collectate fluid. Said disposable test device is then processed as previously described.
The luciferin/luciferase chemiluminescent reactions for ATP are well known. Other chemiluminescent reactions employing bacterial luciferase reactions, or luminols for total microbial determinations can be easily adapted to the methods and devices of the present invention.
The invention further concerns a detection method in which the presence and quantity of specific microbes on a surface can be detected in a time frame less than one hour, said method comprising the steps of:
a) Providing a clean disposable test device comprising an open top, translucent sides, and a porous filter attached to the bottom side,
b) Adding an aliquot of collectate, said collectate being that described as above,
c) Adding an appropriate wash solution comprised of detergent, or buffered salts or a combination thereof,
d) Applying positive pressure to the top of the disposable test device, or negative pressure to the bottom of the disposable test device to remove fluid from the device and deposit microbes or target analytes directly or indirectly onto the surface of the porous filter,
e) Adding a specific labeled antibody directed against the specific microbes to be detected and incubating for an appropriate period of time,
f) Applying positive pressure to the top of the disposable test device, or negative pressure to the bottom of the disposable test device to remove fluid containing unreacted enzyme labeled antibody from the device,
g) Adding an appropriate wash solution comprised of detergent and buffered salts,
h) applying positive pressure to the top of the disposable test device, or negative pressure to the bottom of the disposable test device to further remove fluid containing unreacted labeled antibody from the device,
i) Adding a chemiluminescent substrate and determining the amount of light emitted by the chemiluminescent substrate using a photometer that accommodates the disposable test device in a manner which allows its precise positioning with respect to the surface of the photosensor and which precludes any possible loss of the final reaction mixture during and after the measurement cycle.
The method described above can also be modified by adding capture particles such as latex spheres coated with a binder such as specific antibody to antigens of the target microbe into the disposable test device prior to performing step (d). The method can also be modified so that capture particles and enzyme labeled antibody and the collectate are all simultaneously reacted within the disposable test device, prior to performing step (f).
Various buffers for extracting antigens and washing immune complexes are well known to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a drawing of the collection apparatus means comprising a shaft, absorbent tip, and a container with fluid.
FIG. 2 is a drawing of the collection apparatus means comprising a sponge and a bag with fluid.
FIG. 3 is a drawing of a large volume concentrating apparatus.
FIG. 4 is an exploded perspective view of a large volume concentrating apparatus.
FIG. 5 is a drawing of a negative pressure apparatus.
FIG. 6 is an exploded perspective drawing of a positive pressure apparatus, disposable test device and holder with absorbent pad.
FIG. 7 is a drawing of the disposable test device, its respective positioning into the complementary draw slide and the relationship to the photosensor means.
FIG. 8 shows the comparison of the total plate count obtained after 48 hours of incubation and the relative light units obtained from the 5 minutes bioluminescent procedure outlined in the preferred embodiment. Each data point was from a single beef carcass.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the following description, the various forms of the method of the invention and the uses of the various forms of the apparatus therein will be described in exemplary terms only, as a general bacterial screen and as a specific test for Salmonella. This discussion, however, is simply to illustrate the steps of the method and the structure and use of the devices and apparatus therein. The best modes, as described hereinafter, are accordingly, to be considered exemplary and not limiting as to the scope and concept of the invention.
One aspect of the invention is the collection device. FIG. 1 is a drawing of a collection apparatus means comprised of a shaft (1) and absorbent tip (2). The absorbent tip is wetted with an excess of collection fluid (3) and used to wipe a circumscribed area of a surface to be monitored. After wiping the area, the absorbent tip is place into a container (4) and agitated to release any of the absorbed bacteria into the collection fluid.
Referring to FIG. 2 is a drawing of a collection apparatus means comprised of a sponge. The sponge (5) is wetted with collection fluid (3) and used to wipe a circumscribed area of a surface to be monitored. After wiping the area, the sponge is placed into a plastic bag (6) containing excess collection fluid and squeezed several times to release any of the absorbed bacteria into the collection fluid. The volume of collectate fluid can vary depending upon the size of the absorbent and area wiped. The collection fluid is selected to ensure transfer of the microbial contaminants from the test surface to the collection device and then to a disposable test device. Generally the pH of the collection fluid is between 5 and 8, but preferably between 6.0 to 7.0 and contains salts such as sodium chloride between 0.1M and 0.3M, preferably about 0.25M NaCl to ensure survival of bacteria. The collection fluid should contain a detergent such as 0.05% tween 20 to ensure that the bacteria are easily removed from the test surface and collection apparatus.
Referring to FIG. 3 is a drawing of a large volume concentrating apparatus (7), in which a quantity of collectate fluid can be collected into a disposable test device. An appropriate sized luer-tipped syringe is attached to the inlet (8) of large volume concentrating apparatus and then positive pressure applied to the syringe plunger causing the collectate fluid to flow out of the outlet (9).
Referring to FIG. 4 is an exploded perspective view of the large volume concentrating apparatus, the collectate fluid flows through the filter bottom (11) of the disposable test device (10). O rings (14) and (15) provide a leakproof seal. After completion of concentrating the collectate, upper compartment (13) is separated from the lower compartment (16) to expose the lip (12) of the disposable test device. The disposable test device is then manually removed from the lower compartment.
Referring to FIG. 5 is a negative pressure device (17) in which the bottom portion of the disposable test device is inserted into holes (18). Appropriate volume of wash or somatic cell lysing solutions can be added and a vacuum can be applied to outlet (19) to remove fluid from the disposable test device.
Referring to FIG. 6 is an expanded perspective drawing of a positive pressure apparatus (20) comprised of a plunger (19) and a barrel (21), a disposable test device (10), and device holder (25) comprised of an absorbent pad (26) to absorb the fluid waste. The disposable test device is inserted into holder (24). An aliquot of collectate fluid (i.e. 50 to 100 μl) is added and an appropriate volume of wash or somatic cell lysing solutions can be added. The rubber seal (23) of the positive pressure device is positioned on top of the disposable test device. Applying pressure to plunger (19) forces air through barrel (20) and out through outlet (22) displacing the fluid which passes into the absorbent pad. Additional wash solution can be added and the process repeated.
Referring to FIG. 7 is a drawing of the disposable test device (10), its respective positioning (28) into the draw slide (27), and the relationship to the photosensor means (30). The body of the disposable test device (10) is comprised of optically clear molded plastic material, such as polystyrene, which is capable of nearly complete transmission of light within a 500-600 nm wavelength range. Fused to the lower surface of the device is a semi-permeable membrane (11) which is characterized by its strength and lack of deformation under pressure, and a pore size distribution which insures surface retention of bacterial cells, while facilitating complete passage of any associated liquid phase during pressurization. This membrane must also have sufficient surface tension to retain the measurement solution even after wetting.
The draw slide is an integral part of a luminometer instrument. The draw slide is pulled out and the disposable test device is positioned into hole (28) so that a window to the translucent wall of the disposable test device is exposed to the photosensor means when the draws slide is returned to a complementary dark chamber of the luminometer.
In a general bacterial screen based on bioluminescence, after a microbial sample has been concentrated in the disposable test device, a bacteriolytic reagent is added to lyse the bacteria and free the ATP. An appropriate volume of luminescent substrate (i.e. luciferin-luciferase) is added to the disposable test device and the draw slide is returned to the dark chamber of the luminometer. Measurement of light emission is made by digitalizing or converting the electrical signal from the photosensor means to a number of relative light units. If the method is to be used to detect specific bacteria, a specific antibody conjugated to a chemiluminescent or enzyme probe is added. In the preferred embodiment, the antibody is placed in the disposable test device and allowed to react for 10 minutes. Additional wash steps may be performed by adding a wash solution and evacuating the wash solution. A luminescent substrate solution is then added. In the preferred embodiment such substrate consists of a mixture of hydrogen peroxide and luminol. The draw slide is returned to the dark chamber of the luminometer. Measurement of light emission is made by digitalizing or convening the electrical signal from the photosensor means to a number of relative light units.
The invention is further illustrated by means of the following examples.
EXAMPLE 1
General Bacterial Screen on Hard Surfaces
This example involves a procedure for testing a stainless steel surface for the presence of microbial contamination.
Escherichi coli were grown on tryptic soy agar for 18 hours at 30° C. A sample of the bacteria was introduced into 10 mls of peptic soy broth and incubated for an additional 18 hours. Bacteria were harvested by centrifugation and washed three times in 0.9% NaCl that had been sterile filtered. The optical density of the solution was measured at 650 nm and the concentration was adjusted so that the optical density was 0.300. Three serial 10-fold dilutions were prepared to arrive at a concentration of 10 5 microbes/ml. 100 μl of this solution was dribbled over an area of 10×10 cm demarcated on the surface or a stainless steel sheet that had been previously cleaned with bleach, alcohol and sterile distilled water. The solution containing the bacteria was allowed to dry for 5 hours at room temperature. Control demarcated areas were prepared with no bacteria.
Individual sponges of 10×10 mm were premoistened with approximately 750 μl of a collection fluid comprised of 0.15M NaCl containing 0.05% Tween 20 in a bag. This solution was just sufficient to completely wet the sponge. Each sponges was removed from a bag and wiped over demarcated areas of the surface with 10 strokes in each direction. The sponge was then returned to the bag and squeezed manually ten times yielding a collectate. An aliquot (25 μl) of the collectate was removed from the bag and placed in a disposable test device. 25 μl of bacterial releasing reagent was added and 50 μl of a luciferin/luciferase/magnesium mixture was added. The draw slide was closed and the relative light units determined.
In a second set of experiments, swabs were premoistened with approximately 300 μl of collection fluid in a bag as outlined above. The swabs were used to wipe similarly demarcated areas of a stainless steel surface as described above.
In each case, control areas which had not had bacteria seeded on the surface were also tested. In addition, the bacterial solution that had been seeded onto the surface was placed directly into the collection fluid as a positive control. Each data point represents the average of three samplings. Referring to Table 1, approximately 80% of seeded bacteria could be detected using either a sponge or a swab as a collection means.
TABLE 1__________________________________________________________________________ Positive Sample % Negative Control Control Direct from Seeded RecoveryCollection Surface (Relative Seeding (Relative Surface (Relative of SeededDevice Light Units) Light Units) Light Units) Bacteria__________________________________________________________________________Sponge 0 115 88 79%Swab 0 330 272 82%__________________________________________________________________________
EXAMPLE 2
General Bacterial Screen on Carcasses
This example involves a procedure for testing the surface of beef, pork, and poultry carcasses in a slaughterhouses for the presence of microbial contamination.
Testing of beef carcasses was performed in the slaughterhouse environment. Carcasses were sampled immediately before washing (alter trimming) and after the final wash. A test area on the carcass was sectioned off with either a stainless steel template defining an area of 500 cm2 or an area of that size was marked with edible ink. Random sites on the carcass were chosen for sampling.
Samples were taken with disposable sponges prepackaged in sterile bags. The sponges were premoistened by incubation with 25 ml of collection solution containing 0.085% NaCl with 0.05% Tween 20, pH 7.2. Before sampling, the excess collection fluid is mechanically expressed from the sponge. The marked area was sampled by wiping the sponge over the area approximately 15 times in both the horizontal and the vertical directions. The sponge was returned to the bag and mechanically agitated using a stomacher apparatus for two minutes.
50 μl of the sample was removed from the collection fluid and added to a disposable test device. 100 μl of wash solution comprising 0.05% saponin in 0.1M Hepes buffer, pH 7.75 was added. Using a positive pressure device, the fluid phase in the disposable test device was passed through the membrane onto a pad of paper towels. An additional 150 μl of wash solution was added and using positive pressure was passed through the membrane of the device onto a pad of paper towels. The disposable test device was placed into the drawslide of a luminometer and 30 μl of bacterial releasing reagent consisting of 0.1M benzyal konium chloride in Hepes buffer, pH 7.75 were added followed by addition of 30 μl of luciferin/luciferase/magnesium solution. The draw slide of the luminometer was closed and the light emission was read. The entire procedure required under 5 minutes to perform per sample. The results were expressed in relative light units. An aliquot of the collectate was also treated in the conventional manner of streaking the material on tryptic soy agar plates and incubating the plates for 40 hours at 30° C. after which total plate counts were determined by an automated colony plate counter.
FIG. 8 shows the relative correlation between the plate counts determined by an automated plate counter compared with the relative light units for samples from 160 carcasses sampled at two sites. Each value is expressed as its arithmetic log. Similar data was collected for 400 carcasses at each of two sites. For this data, the correlation coefficient between the log of the relative light units (log mATP) and the log of the aerobic plate counts (log APC) was 0.92.
Similar in-plant studies were performed on 320 pork carcasses taken in three commercial plants. The correlation coefficient between log mATP and log APC was 0.92.
Comparative mATP and APC data were obtained on 330 poultry samples from two commercial poultry plants at four locations in the plant: post-pick, post evisceration, post-final wash, and post chill. The correlation between log mATP and log APC was 0.85.
EXAMPLE 3
Chemiluminescent Salmonella Assays
This example involves a procedure for testing for the presence of salmonella.
Bacteria, either Salmonella typhimurium, ATCC 14028 or Aeromonas hydrophila, ATCC 7966, were streaked from frozen stocks onto tryptic soy agar plates and incubated for 18 hours at 26° C. Bacterial colonies were harvested into sterile 0.9% NaCl and washed three times by centrifugation and resuspension in 0.9% NaCl. The optical density of the solution was measured at 650 nm and the concentration was adjusted so that the optical density was 0.300 by diluting the bacteria in 0.05M Tris, 0.05M EDTA, 0.15M NaCl, pH 8.2.
An aliquot (10 μl) of a 0.5% solution of latex microspheres coated with antibody to salmonella was added to the disposable test device. An aliquot, 100 μl, of the diluted bacteria were placed in a disposable test device with a filter on the bottom surface composed of 1.2 micron Biodyne C. After the aliquot of the bacteria was added the solution was allowed to sit for 10 minutes.
Positive pressure was applied and the fluid was evacuated onto an absorbent pad. The trapped antigens were washed by adding 200 μl of wash solution consisting of 0.01M PBS, pH 7.2 containing 0.05% Tween 20. Positive pressure was again applied and the fluid was evacuated onto an absorbent pad. A horseradisch peroxidase labeled antibody directed against Salmonella was added to the disposable test device and allowed to sit for 10 minutes at room temperature. Positive pressure was again applied and the fluid evacuated from the disposable test device. A wash solution was added and evacuated with positive pressure two more times. The disposable test device was placed in a luminometer. 100 μl of Lumiglo Chemiluminescent substrate (Kirkegaard and Perry Laboratory, Gaithersburg, Md.) was added, the drawer slide was immediately closed and the light emission determined.
The results shown in Table 2 indicate that the concentrations as low as 10 5 organisms could be easily distinquished from a negative control using this system.
TABLE 2______________________________________Results of a Test for Salmonella Relative Light Relative Light Units for Units forTotal Number Salmonella Aeromonas Signal toof Organisms typhimurium hydrophila Noise Ratio______________________________________10.sup.8 18,940 5,290 3.610.sup.7 13,780 2.610.sup.6 10,720 2.010.sup.5 9,220 1.7______________________________________
A second procedure was used similar to that detailed above, except that no latex beads were added to the disposable test device prior to the introduction of the aliquot of the bacteria. In this case, the signal to noise ratio for a solution of S. typhimurium (10 8 organisms): A. hydrophila (10 8 organisms) was 5.91.
A third procedure was also tested. In this method, 40 μl of latex microspheres coated with antbody to salmonella, 40 μl of sample, and 40 μl of horseradish peroxidase labeled anti-salmonella antibody were added to a disposable test device. The mixture was incubated for 20 minutes at room temperature. Positive pressure was used to evacuate the fluid from the test device. The trapped material was washed three times by introduction of 200 μl of 0.01M phosphate buffered saline pH 7.2 containing 0.05% Tween 20 followed by evacuation of the fluid from the disposable test device using positive pressure. The disposable test device was placed in the luminometer and 100 μl of Lumiglo Chemiluminescent substrate (Kirkegarrd and Perry Laboratories, Gaithersburg, Md.) was added. The drawslide was immediately closed, and the light emission determined. The signal to noise ratio for a solution of S. typhimurium (10 6 organisms): A. hydrophila (10 6 organisms) was 1.83.
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A method for determining the presence and concentration of total microbial contamination or the presence and concentration of a specific microbial species on a surface is described. The method consists of a means of a collection device and fluid for removing the microbes from the surface and suspending them in a fluid phase. An aliquot of the fluid phase is introduced into a disposable test device which allows filtration of the sample to remove extraneous substances including somatic cells, and concentration of the microbes. The total concentration of microbes is determined by adding a bacterial releasing reagent and a luminescent reagent to the disposable test device and introducing the disposable test device into a luminometer that can read the luminescence from the side wall. The presence and concentration of specific microbial species is determined by adding an aliquot of the fluid phase described above to the dispoable test device, washing the sample, then adding a specific labeled antibody directed against the microbes to be detected to the test device, washing then adding a luminescent reagent to the disposable test device. The test device is then introduced into the luminometer. The relative light units determine the presence and quanity of microbes present. In both cases, the microbe is identified and/or the concentration is determined in less than 1 hour and generally in less than 5 minutes.
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TECHNICAL FIELD
This invention relates to compounds having activity to inhibit leukotriene biosynthesis, to pharmaceutical compositions comprising these compounds, and to a medical method of treatment. More particularly, this invention concerns certain substituted aryl- and heteroaryl-alkenyl-N-hydroxyureas which inhibit leukotriene biosynthesis, to pharmaceutical compositions comprising these compounds and to a method of inhibiting 5-lipoxygenase activity and leukotriene biosynthesis.
BACKGROUND OF THE INVENTION
5-Lipoxygenase is the first dedicated enzyme in the pathway leading to the biosynthesis of leukotrienes. This important enzyme has a rather restricted distribution, being found predominantly in leukocytes and mast cells of most mammals. Normally 5-lipoxygenase is present in the cell in an inactive form; however, when leukocytes respond to external stimuli, intracellular 5-lipoxygenase can be rapidly activated. This enzyme catalyzes the addition of molecular oxygen to fatty acids with cis,cis-1,4-pentadiene structures, converting them to 1-hydroperoxy-trans,cis-2,4-pentadienes. Arachidonic acid, the 5-lipoxygenase substrate which leads to leukotriene products, is found in very low concentrations in mammalian cells and must first be hydrolyzed from membrane phospholipids through the actions of phospholipases in response to extracellular stimuli. The initial product of 5-lipoxygenase action on arachidonate is 5-HPETE which can be reduced to 5-HETE or converted to LTA 4 . This reactive leukotriene intermediate is enzymatically hydrated to LTB 4 or conjugated to the tripeptide glutathione to produce LTC 4 . LTA 4 can also be hydrolyzed nonenzymatically to form two isomers of LTB 4 . Successive proteolytic cleavage steps convert LTC.sub. 4 to LTD 4 and LTE 4 . Other products resulting from further oxygenation steps have also been described in the literature. Products of the 5-lipoxygenase cascade are extremely potent substances which produce a wide variety of biological effects, often in the nanomolar to picomolar concentration range.
The remarkable potencies and diversity of actions of products of the 5-lipoxygenase pathway have led to the suggestion that they play important roles in a variety of diseases. Alterations in leukotriene metabolism have been demonstrated in a number of disease states including asthma, allergic rhinitis, rheumatoid arthritis and gout, psoriasis, adult respiratory distress syndrome, inflammatory bowel disease, endotoxin shock syndrome, atherosclerosis, ischemia induced myocardial injury, and central nervous system pathology resulting from the formation of leukotrienes following stroke or subarachnoid hemorrhage.
The enzyme 5-lipoxygenase catalyzes the first step leading to the biosynthesis of all the leukotrienes and therefore inhibition of this enzyme provides an approach to limit the effects of all the products of this pathway. Compounds which inhibit 5-lipoxygenase are thus useful in the treatment of disease states such as those listed above in which the leukotrienes play an important role.
U.S. Pat. No. 4,738,986 to Kneen, et al. discloses and claims N-(3-phenoxycinnamyl)acetohydroxamic acid, its salts and related compounds having utility for inhibiting lipoxygenase and cyclooxygenase enzymes.
European Patent Application 299 761 to Salmon, et al. discloses and claims certain (substituted phenoxy)phenylalkenyl hydroxamic acids and their salts which are useful as agents for inhibiting lipoxygenase and cyclooxygenase activity.
European Patent Application Serial No. 93 904 979.7 filed Feb. 8, 1993 to Brooks, et al. discloses and claims certain (substituted furanylalkenyl-N-hydroxyureas and hydroxamic acids having lipoxygenase inhibiting activity.
SUMMARY OF THE INVENTION
In its principal embodiment, the present invention provides certain substituted aryl- and heteroaryl-alkenyl-N-hydroxyurea compounds which inhibit 5-lipoxygenase enzyme activity and are useful in the treatment of allergic and inflammatory disease states in which leukotrienes play a role including including asthma, allergic rhinitis, rheumatoid arthritis and gout, psoriasis, adult respiratory distress syndrome, inflammatory bowel disease, endotoxin shock syndrome, ischmemia induced myocardial injury, atherosclerosis and central nervous system pathology resulting from the formation of leukotrienes following stroke or subarachnoid hemorrhage.
The present invention provides a compound of formula ##STR2## or a pharmaceutically acceptable salt thereof in which R 2 and R 3 are independently selected from hydrogen, alkyl of one to twelve carbon atoms, halogen and trifluoromethyl. M represents hydrogen, a pharmaceutically acceptable cation, or a pharmaceutically acceptable metabolically cleavable group; B is a straight or branched divalent alkylene group of one to twelve carbon atoms; and L is alkylene of one to six carbon atoms.
Z is selected from (a) thienyl, optionally substituted with alkyl of one to six carbon atoms, or haloalkyl of one to six carbon atoms; (b) thiazolyl, optionally substituted with alkyl of one to six carbon atoms or haloalkyl of one to six carbon atoms, (c) oxazolyl, optionally substituted with alkyl of one to six carbon atoms or haloalkyl of one to six carbon atoms, and (d) furanyl, optionally substituted with alkyl of one to six carbon atoms or haloalkyl of one to six carbon atoms.
A is selected from (a) optionally substituted phenyl, (b) optionally substituted naphthyl, where the optional substituents on the phenyl or naphthyl groups are selected from the group consisting of (1) alkyl of one to six carbon atoms, (2) haloalkyl of one to six carbon atoms, (3) hydroxyalkyl of one to six carbon atoms, (4) alkoxy of one to twelve carbon atoms, (5) alkoxyalkoxyl in which the two alkoxy portions may each independently contain one to six carbon atoms, (6) alkylthio of one to six carbon atoms, (7) hydroxy, (8) halogen, (9) cyano, (10) amino, (11) alkylamino of one to six carbon atoms, (12) dialkylamino in which the two alkyl groups may independently contain one to six carbon atoms, (12) alkanoylamino of two to eight carbon atoms, (13) N-alkanoyl-N-alkylamino in which the alkanoyl portion may contain from two to eight carbon atoms and the alkyl groups may each independently contain one to six carbon atoms, (14) alkylaminocarbonyl of two to eight carbon atoms, (15) dialkylaminocarbonyl in which the two alkyl groups may independently contain one to six carbon atoms, (16) carboxyl, (17) alkoxycarbonyl of two to eight carbon atoms, (18) phenyl, optionally substituted with alkyl of one to six carbon atoms, haloalkyl of one to six carbon atoms, alkoxy of one to six carbon atoms, hydroxy, or halogen, (19) phenoxy, optionally substituted with alkyl of one to six carbon atoms, haloalkyl of one to six carbon atoms, alkoxy of one to six carbon atoms, hydroxy, or halogen, (20) phenylthio, optionally substituted with alkyl of one to six carbon atoms, haloalkyl of one to six carbon atoms, alkoxy of one to six carbon atoms, hydroxy, or halogen, (21) pyridyl, optionally substituted with alkyl of one to six carbon atoms, haloalkyl of one to six carbon atoms, alkoxy of one to six carbon atoms, hydroxy, halogen, or phenyl optionally substituted with alkyl or halogen, (22) pyridyloxy, optionally substituted alkyl of one to six carbon atoms, haloalkyl of one to six carbon atoms, alkoxy of one to six carbon atoms, hydroxy, or halogen; (c) optionally substituted furyl, where the optional substituents are selected from (c-1) alkyl of one to six carbon atoms, (c-2) haloalkyl of one to six carbon atoms, (c-3) halogen, (c-4) phenyl, optionally substituted with alkyl of one to six carbon atoms, haloalkyl of one to six carbon atoms, alkoxy of one to six carbon atoms, hydroxy, or halogen, (c-5) phenoxy, optionally substituted with alkyl of one to six carbon atoms, haloalkyl of one to six carbon atoms, alkoxy of one to six carbon atoms, hydroxy, or halogen, (c-6) phenylthio, optionally substituted with alkyl of one to six carbon atoms, haloalkyl of one to six carbon atoms, alkoxy of one to six carbon atoms, hydroxy, or halogen, (c-7) pyridyl, optionally substituted with alkyl of one to six carbon atoms, haloalkyl of one to six carbon atoms, alkoxy of one to six carbon atoms, hydroxy, or halogen, and (c-8) pyridyloxy, optionally substituted with alkyl of one to six carbon atoms, haloalkyl of one to six carbon atoms, alkoxy of one to six carbon atoms, hydroxy, or halogen; (d) optionally substituted thienyl, where the optional substituents are selected from the group consisting of (d-1) alkyl of one to six carbon atoms, (d-2) phenyl, optionally substituted with alkyl of one to six carbon atoms, haloalkyl of one to six carbon atoms, alkoxy of one to six carbon atoms, hydroxy, or halogen, (d-3) phenoxy, optionally substituted with alkyl of one to six carbon atoms, haloalkyl of one to six carbon atoms, alkoxy of one to six carbon atoms, hydroxy, or halogen, (d-4) phenylthio, optionally substituted with alkyl of one to six carbon atoms, haloalkyl of one to six carbon atoms, alkoxy of one to six carbon atoms, hydroxy, or halogen, (d-5) pyridyl, optionally substituted with alkyl of one to six carbon atoms, haloalkyl of one to six carbon atoms, alkoxy of one to six carbon atoms, hydroxy, or halogen, and (d-6) pyridyloxy, optionally substituted with alkyl of one to six carbon atoms, haloalkyl of one to six carbon atoms, alkoxy of one to six carbon atoms, hydroxy, or halogen; (e) optionally substituted benzo[b]furyl; (f) optionally substituted benzo[b]thienyl; (g) optionally substituted pyridyl; and (h) optionally substituted quinolyl, where the optional substituents on the benzo[b]furyl, benzo[b]thienyl, pyridyl, and quinolyl groups are selected from alkyl of one to six carbon atoms, haloalkyl of one to six carbon atoms, alkoxy of one to six carbon atoms, hydroxy, and halogen.
In another embodiment, the present invention provides pharmaceutical compositions which comprise a therapeutically effective amount of compound as defined above in combination with a pharmaceutically acceptable carrier.
In yet another embodiment, the present invention provides a method of inhibiting leukotriene biosynthesis in a host mammal in need of such treatment comprising administering to a mammal in need of such treatment a therapeutically effective amount of a compound as defined above.
DETAILED DESCRIPTION
As used throughout this specification and the appended claims, the following terms have the meanings specified.
The term "alkyl" refers to a monovalent group derived from a straight or branched chain saturated hydrocarbon by the removal of a single hydrogen atom. Alkyl groups are exemplified by methyl, ethyl, n- and iso-propyl, n-, sec-, iso- and tert-butyl, and the like.
The term "alkylamino" refers to a group having the structure --NHR' wherein R' is alkyl, as previously defined, Examples of alkylamino include methylamino, ethylamino, iso-propylamino and the like.
The term "alkylaminocarbonyl" refers to an alkylamino group, as previously defined, attached to the parent molecular moiety through a carbonyl, >C═O, group. Examples of alkylaminocarbonyl include methylaminocarbonyl, ethylaminocarbonyl, iso-propylaminocarbonyl and the like.
The term "alkylthio" refers to an alkyl group, as defined above, attached to the parent molecular moiety through a sulfur atom and includes such examples as methylthio, ethylthio, propylthio, n-, sec- and tert-butylthio and the like.
The term "alkanoyl" represents an alkyl group, as defined above, attached to the parent molecular moiety through a carbonyl group. Alkanoyl groups are exemplified by acetyl, propionyl, butanoyl and the like.
The term "alkanoylamino" refers to an alkanoyl group, as previously defined, attached to the parent molecular moiety through a nitrogen atom. Examples of alkanoylamino include formamido, acetamido, and the like.
The term "N-alkanoyl-N-alkylamino" refers to an alkanoyl group, as previously defined, attached to the parent molecular moiety through an aminoalkyl group. Examples of N-alkanoyl-N-alkylamino include N-methyl-formamido, N-methyl-acetamido, and the like.
The terms "alkoxy" and "alkoxyl" denote an alkyl group, as defined above, attached to the parent molecular moiety through an oxygen atom. Representative alkoxy groups include methoxyl, ethoxyl, propoxyl, butoxyl, and the like.
The term "alkoxyalkoxyl) refers to an alkyl group, as defined above, attached through an oxygen to an alkyl group, as defined above, attached through an oxygen to the parent molecular moiety. Examples of alkoxyalkoxyl include methoxymethoxyl, methoxyethyoxyl, ethoxyethoxyl and the like.
The term "alkoxyalkyl" refers to an alkoxy group, as defined above, attached through an alkylene group to the parent molecular moiety.
The term "alkoxycarbonyl" represents an ester group; i.e. an alkoxy group, attached to the parent molecular moiety through a carbonyl group such as methoxycarbonyl, ethoxycarbonyl, and the like.
The term "alkenyl" denotes a monovalent group derived from a hydrocarbon containing at least one carbon-carbon double bond by the removal of a single hydrogen atom. Alkenyl groups include, for example, ethenyl, propenyl, butenyl, 1-methyl-2-buten-1-yl and the like.
The term "alkylene" denotes a divalent group derived from a straight or branched chain saturated hydrocarbon by the removal of two hydrogen atoms, for example methylene, 1,2-ethylene, 1,1-ethylene, 1,3-propylene, 2,2-dimethylpropylene, and the like.
The term "alkenylene" denotes a divalent group derived from a straight or branched chain hydrocarbon containing at least one carbon-carbon double bond. Examples of alkenylene include --CH═CH--, --CH 2 CH═CH--, --C(CH 3 )═CH--, --CH 2 CH═CHCH 2 --, and the like.
The term "alkynylene" refers to a divalent group derived by the removal of two hydrogen atoms from a straight or branched chain acyclic hydrocarbon group containing a carbon-carbon triple bond. Examples of alkynylene include --CH∫CH--, --CH∫C--CH 2 --, --CH∫CH--CH(CH 3 )-- and the like.
The term "carbocyclic aryl" denotes a monovalent carbocyclic ring group derived by the removal of a single hydrogen atom from a monocyclic or bicyclic fused or non-fused ring system obeying the "4n+2 p electron" or Huckel aromaticity rule. Examples of carbocyclic aryl groups include phenyl, 1- and 2-naphthyl, biphenylyl and the like.
The term "(carbocyclic aryl)alkyl" refers to a carbocyclic ring group as defined above, attached to the parent molecular moiety through an alkylene group. Representative (carbocyclic aryl)alkyl groups include phenylmethyl or benzyl, phenylethyl, phenylpropyl, 1-naphthylmethyl, and the like.
The term "carbocyclic aryloxyalkyl" refers to a carbocyclic aryl group, as defined above, attached to the parent molecular moiety through an oxygen atom and thence through an alkylene group. Such groups are exemplified by phenoxymethyl, 1- and 2-naphthyloxymethyl, phenoxyethyl and the like.
The term "(carbocyclic aryl)alkoxyalkyl" denotes a carbocyclic aryl group as defined above, attached to the parent molecular moiety through an alkoxyalkyl group. Representative (carbocyclic aryl)alkoxyalkyl groups include phenylmethoxymethyl, phenylethoxymethyl, 1- and 2-naphthylmethoxyethyl, and the like.
"Carbocyclic arylthioalkyl" represents a carbocyclic aryl group as defined above, attached to the parent molecular moeity through a sulfur atom and thence through an alklyene group and are typified by phenylthiomethyl, 1- and 2-naphthylthioethyl and the like.
The term "dialkylamino" refers to a group having the structure --NR'R" wherein R' and R" are independently selected from alkyl, as previously defined. Additionally, R' and R" taken together may optionally be --(CH 2 ) kk -- where kk is an integer of from 2 to 6. Examples of dialkylamino include, dimethylamino, diethylaminocarbonyl, methylethylamino, piperidino, and the like.
The term "haloalkyl" denotes an alkyl group, as defined above, having one, two, or three halogen atoms attached thereto and is exemplified by such groups as chloromethyl, bromoethyl, trifluoromethyl, and the like.
The term "hydroxyalkyl" represents an alkyl group, as defined above, substituted by one to three hydroxyl groups with the proviso that no more than one hydroxy group may be attached to a single carbon atom of the alkyl group.
The term "phenoxy" refers to a phenyl group attached to the parent molecular moiety through an oxygen atom.
The term "phenylthio" refers to a phenyl group attached to the parent molecular moiety through a sulfur atom.
The term "pyridyloxy" refers to a pyridyl group attached to the parent molecular moiety through an oxygen atom.
The term "metabolically cleavable group" denotes a group which is cleaved in vivo to yield the parent molecule of the structural formulae indicated above wherin M is hydrogen. Examples of metabolically cleavable groups include --COR, --COOR, --CONRR and --CH 2 OR radicals where R is selected independently at each occurrence from alkyl, trialkylsilyl, carbocyclic aryl or carbocyclic aryl substituted with one or more of C 1 -C 4 alkyl, halogen, hydroxy or C 1 -C 4 alkoxy. Specific examples of representative metabolically cleavable groups include acetyl, methoxycarbonyl, benzoyl, methoxymethyl and trimethylsilyl groups.
By "pharmaceutically acceptable salt" it is meant those salts which are, within the scope of sound medical judgement, suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response and the like, and are commensurate with a reasonable benefit/risk ratio. Pharmaceutically acceptable salts are well known in the art. For example, S. M Berge, et al. describe pharmaceutically acceptable salts in detail in J. Pharmaceutical Sciences, 1977, 66: 1-19. The salts can be prepared in situ during the final isolation and purification of the compounds of the invention, or separately by reacting the free base function with a suitable organic acid. Representative acid addition salts include acetate, adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphersulfonate, citrate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, fumarate, glucoheptonate, glycerophosphate, hemisulfate, heptonate, hexanoate, hydrobromide, hydrochloride, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, toluenesulfonate, undecanoate, valerate salts, and the like. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like, as well as nontoxic ammonium, quaternary ammonium, and amine cations, including, but not limited to ammonium, tetramethylammonium, tetraethylammonium, methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine, and the like.
Asymmetric centers may exist in the compounds of the present invention. The present invention contemplates the various stereoisomers and mixtures thereof. Starting compounds of particular stereochemistry are either commercially available or are made by the methods detailed below and resolved by techniques well known in the organic chemical arts.
Compounds falling within the scope of the present invention include, but are not limited to:
Z-(R)-N-[3-(5-(4-Fluorophenylmethyl)-thien-2-yl)-1-methyl-2-propenyl]-N-hydroxyurea,
E-(R)-N-[3-(5-(4-Fluorophenylmethyl)-thien-2-yl)-1 -methyl-2-propenyl]-N-hydroxyurea,
Z-N-[3-(5-(4-Fluorophenylmethyl)-thien-2-yl)-1-methyl-2-propenyl]-N-hydroxyurea,
E-N-[3-(5-(4-Fluorophenylmethyl)-thien-2-yl)-1-methyl-2-propenyl]-N-hydroxyurea,
Z-N-[3-(5-(4-Fluorophenylmethyl)-fur-2-yl)-1-methyl-2-propenyl]-N-hydroxyurea,
E-N-[3-(5-(4-Fluorophenylmethyl)-fur-2-yl)-1-methyl-2-propenyl]-N-hydroxyurea,
Z-(R)-N-{3-[5-(4-fluorophenylmethyl)thiazo-2-yl]-1-methyl-2-propenyl}-N-hydroxyurea,
E-(R)-N-{3-[5-(4-fluorophenylmethyl)thiazo-2-yl]-1-methyl-2-propenyl}-N-hydroxyurea,
Z-(R)-N-[3-(5-(4-chlorophenylmethyl)-thien-2-yl)-1-methyl-2-propenyl]-N-hydroxyurea,
Z-(R)-N-(3-(5-(3-pyridylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea,
Z-(R)-N-(3-(5-(4-pyridylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea,
Z-(R)-N-(3-(5-(2-pyridylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea,
Z-(R)-N-(3-(5-(thien-2-ylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea,
Z-(R)-N-(3-(5-(2-naphthylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea,
Z-(R)-N-(3-(5-(2-quinolylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea,
Z-(R)-N-(3-(5-(4-fluorophenylethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea,
Z-(R)-N-(3-(4-(4-fluorophenylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea,
Z-(R)-N-(3-(5-(4-biphenylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea,
Z-(R)-N-(3-(5-(thiazo-4-ylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea,
Z-(R)-N-(3-(5-(benzo[b]thien-2-ylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea,
Z-(R)-N-(3-(5-(thiazo-2-ylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea, and
Z-N-(3-(5-(4-fluorophenylmethyl)thien-2-yl)-2-propenyl)-N-hydroxyurea.
Preferred compounds of this invention are those in which Z is optionally substituted thienyl. Particularly preferred compounds are the E (trans)- and Z (cis)-(R)-N-(3-(5-(4-fluorophenylmethyl)-thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea.
Leukotriene Biosynthesis Inhibition Determination
Inhibition of leukotriene biosynthesis was evaluated in an assay, involving calcium ionophore-induced LTB 4 biosynthesis expressed human whole blood. Human heparinized whole blood was preincubated with test compounds or vehicle for 15 rain at 37° C. followed by calcium ionophore A23187 challenge (final concentration of 8.3 μM) and the reaction terminated after 30 minutes by adding two volumes of methanol containing prostaglandin B 2 as an internal recovery standard. The methanol extract was analyzed for LTB 4 using a commercially available radioimmunoassay.
The compounds of this invention inhibit leukotriene biosynthesis in human whole blood. Representative results for specific examples are: IC 50 =0.04 μM for Example 1 and IC 50 =0.18 μM for Example 2.
Pharmaceutical Compositions
The present invention also provides pharmaceutical compositions which comprise compounds of the present invention formulated together with one or more non-toxic pharmaceutically acceptable carriers. The pharmaceutical compositions may be specially formulated for oral administration in solid or liquid form, for parenteral injection, or for rectal administration.
The pharmaceutical compositions of this invention can be administered to humans and other animals orally, rectally, parenterally, intracisternally, intravaginally, intraperitoneally, topically (as by powders, ointments, or drops), bucally, or as an oral or nasal spray. The term "parenteral" administration as used herein refers to modes of administration which include intravenous, intramuscular, intraperitoneal, intrasternal, subcutaneous and intraarticular injection and infusion.
Pharmaceutical compositions of this invention for parenteral injection comprise pharmaceutically acceptable sterile aqueous or nonaqueous solutions, dispersions, suspensions or emulsions as well as sterile powders for reconstitution into sterile injectable solutions or dispersions just prior to use. Examples of suitable aqueous and nonaqueous carriers, diluents, solvents or vehicles include water, ethanol, polyols (such as glycerol, propylene glycol, polyethylene glycol, and the like), and suitable mixtures thereof, vegetable oils (such as olive oil), and injectable organic esters such as ethyl oleate. Proper fluidity can be maintained, for example, by the use of coating materials such as lecithin, by the maintenance of the required particle size in the case of dispersions, and by the use of surfactants.
These compositions may also contain adjuvants such as preservative, wetting agents, emulsifying agents, and dispersing agents. Prevention of the action of microorganisms may be ensured by the inclusion of various antibacterial and antifungal agents, for example, paraben, chlorobutanol, phenol sorbic acid, and the like. It may also be desirable to include isotonic agents such as sugars, sodium chloride, and the like, Prolonged absorption of the injectable pharmaceutical form may be brought about by the inclusion of agents which delay absorption such as aluminum monostearate and gelatin.
In some cases, in order to prolong the effect of the drug, it is desirable to slow the absorption of the drug from subcutaneous or intramuscular injection. This may be accomplished by the use of a liquid suspension of crystalline or amorphous material with poor water solubility. The rate of absorption of the drug then depends upon its rate of dissolution which, in turn, may depend upon crystal size and crystalline form. Alternatively, delayed absorption of a parenterally administered drug form is accomplished by dissolving or suspending the drug in an oil vehicle.
Injectable depot forms are made by forming microencapsule matrices of the drug in biodegradable polymers such as polylactide-polyglycolide. Depending upon the ratio of drug to polymer and the nature of the particular polymer employed, the rate of drug release can be controlled. Examples of other biodegradable polymers include poly(orthoesters) and poly(anhydrides) Depot injectable formulations are also prepared by entrapping the drug in liposomes or microemulsions which are compatible with body tissues.
The injectable formulations can be sterilized, for example, by filtration through a bacterial-retaining filter, or by incorporating sterilizing agents in the form of sterile solid compositions which can be dissolved or dispersed in sterile water or other sterile injectable medium just prior to use.
Solid dosage forms for oral administration include capsules, tablets, pills, powders, and granules. In such solid dosage forms, the active compound is mixed with at least one inert, pharmaceutically acceptable excipient or carrier such as sodium citrate or dicalcium phosphate and/or a) fillers or extenders such as starches, lactose, sucrose, glucose, mannitol, and silicic acid, b) binders such as, for example, carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidone, sucrose, and acacia, c) humectants such as glycerol, d) disintegrating agents such as agar-agar, calcium carbonate, potato or tapioca starch, alginic acid, certain silicates, and sodium carbonate, e) solution retarding agents such as paraffin, f) absorption accelerators such as quaternary ammonium compounds, g) wetting agents such as, for example, cetyl alcohol and glycerol monostearate, h) absorbents such as kaolin and bentonite clay, and i) lubricants such as talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, and mixtures thereof. In the case of capsules, tablets and pills, the dosage form may also comprise buffering agents.
Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polyethylene glycols and the like.
The solid dosage forms of tablets, dragees, capsules, pills, and granules can be prepared with coatings and shells such as enteric coatings and other coatings well known in the pharmaceutical formulating art. They may optionally contain opacifying agents and can also be of a composition that they release the active ingredient(s) only, or preferentially, in a certain part of the intestinal tract, optionally, in a delayed manner. Examples of embedding compositions which can be used include polymeric substances and waxes.
The active compounds can also be in micro-encapsulated form, if appropriate, with one or more of the above-mentioned excipients.
Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, suspensions, syrups and elixirs. In addition to the active compounds, the liquid dosage forms may contain inert diluents commonly used in the art such as, for example, water or other solvents, solubilizing agents and emulsifiers such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol, dimethyl formamide, oils (in particular, cottonseed, groundnut, corn, germ, olive, castor, and sesame oils), glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and fatty acid esters of sorbitan, and mixtures thereof.
Besides inert diluents, the oral compositions can also include adjuvants such as wetting agents, emulsifying and suspending agents, sweetening, flavoring, and perfuming agents.
Suspensions, in addition to the active compounds, may contain suspending agents as, for example, ethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminum metahydroxide, bentonite, agar-agar, and tragacanth, and mixtures thereof.
Compositions for rectal or vaginal administration are preferably suppositories which can be prepared by mixing the compounds of this invention with suitable nonirritating excipients or carriers such as cocoa butter, polyethylene glycol or a suppository wax which are solid at ambient temperature but liquid at body temperature and therefore melt in the rectum or vaginal cavity and release the active compound.
Compounds of the present invention can also be administered in the form of liposomes. As is known in the art, liposomes are generally derived from phospholipids or other lipid substances. Liposomes are formed by mono- or multilamellar hydrated liquid crystals that are dispersed in an aqueous medium. Any nontoxic, physiologically acceptable and metabolizable lipid capable of forming liposomes can be used. The present compositions in liposome form can contain, in addition to a compound of the present invention, stabilizers, preservatives, excipients, and the like. The preferred lipids are the phospholipids and the phosphatidyl cholines (lecithins), both natural and synthetic.
Methods to form liposomes are known in the art. See, for example, Prescott, Ed., Methods in Cell Biology, Volume XIV, Academic Press, New York, N.Y. (1976), p. 33 et seq.
Dosage forms for topical administration of a compound of this invention include powders, sprays, ointments and inhalants. The active compound is mixed under sterile conditions with a pharmaceutically acceptable carrier and any needed preservatives, buffers, or propellants which may be required. Opthalmic formulations, eye ointments, powders and solutions are also contemplated as being within the scope of this invention.
Actual dosage levels of active ingredients in the pharmaceutical compositions of this invention may be varied so as to obtain an amount of the active compound(s) that is effective to achieve the desired therapeutic response for a particular patient, compositions, and mode of administration. The selected dosage level will depend upon the activity of the particular compound, the route of administration, the severity of the condition being treated, and the condition and prior medical history of the patient being treated. However, it is within the sell of the at to start doses of the compound at levels lower than required for to achieve the desired therapeutic effect and to gradually increase the dosage until the desired effect is achieved.
Generally dosage levels of about 1 to about 50, more preferably of about 5 to about 20 mg of active compound per kilogram of body weight per day are administered orally to a mammalian patient. If desired, the effective daily dose may be divided into multiple doses for purposes of administration, e,g. two to four separate doses per day.
Preparation of Compounds of this Invention
The compounds of this invention can be prepared by a variety of synthetic routes. Representative procedures are outlined as follows.
Scheme 1a illustrates a general route for the preparation of the compounds of this invention involving the assembly of an heteroaryl template that can be functionalized to give the desired acetylenic N-hydroxyurea intermediate which is then reduced by known procedures of synthetic chemistry to provide either the Z (cis) alkene isomer or the E (trans) alkene isomer. The intermediate 2 (where Y1 and Y2 are selected from --O--, --S--, and --CH-- is prepared by a coupling reaction of the two requisite intermediates shown in Scheme 1a. This reaction may be catalyzed by the addition of transition metal catalysts or their salts. The aryl moiety 2 is then converted to an aryl halide 3 or 4 which is then treated in a Pd catalyzed coupling reaction with an alkynyl-N-hydroxyurea, for example, butynyl-N-hydroxyurea, to provide the intermediate alkyne 5. Reduction of 5 by hydrogenation using a palladium catalyst in the presence of lead provides the Z (cis) alkene product 6. Reduction of 5 with diisobutylaluminum hydride provides the E (trans) alkene product 7. ##STR3##
Scheme 1b illustrates an alternative route for the preparation of the acetylenic intermediates used in this invention. The intermediate 10 is prepared by coupling the two requisite intermediates 8 and 9 (where Y1 and Y2 is --O--, --N--, --S--, or --CH--). Hydrolysis of the diethylacetal provides the aldehyde 11, which is oxidized to the intermediate carboxylic acid 12 (for example using NaClO 2 in DMSO followed by NaH 2 PO 4 in water). The carboxylic acid is converted into the iodo compound 123using NaOH, I 2 , and KI. Intermediate 13 is then reacted by the procedures described in Scheme 1a with the 1-methyl-2-propynyl-N-hydroxyurea moiety to provide intermediate 5. ##STR4##
Also, the aryl aldehyde 11 (where Y1 and Y2 are --O--, --N--, --S--, or --CH--) is converted to the substituted butynol 14 by known methods (for example, treatment with carbon tetrabromide, triphenylphosphine and zinc, followed by lithium diisopropylamide and acetaldehyde). Alternatively aryl halide 13 can be converted to the butynol 14 by Pd catalyzed coupling with 3-hydroxybutyne as shown in Scheme 1c. ##STR5##
Another procedure is shown in Scheme 1d and involved the treatment of the substituted butynol 14 (where Y1 and Y2 are --O--, --N--, --S--, or --CH--) with triphenylphosphine, diethyl azodicarboxylate and N,O-bisphenoxycarbonylhydroxylamine followed by treatment with ammonia or ammonium hydroxide to provide the desired N-hydroxyureas 5 of this invention. Alternatively intermediate 13 can be coupled using a suitable palladium catalyst and the 1-methyl-2-propynyl-N-hydroxyurea 4 to give the intermediate 5. ##STR6##
The foregoing may be better understood by reference to the following examples which are provided for illustration and not intended to limit the scope of the inventive concept. The following abbreviations are used: THF for tetrahydrofuran, n-BuLi for n-butyllithium, DMF for N,N-dimethylformamide, CDCl 3 for deuterochloroform, DMSO-d 6 for deuterodimethylsulfoxide, DIBAL for diisobutylaluminum hydride.
EXAMPLE 1
Preparation of Z-(R)-N-[3-(5-(4-Fluorophenylmethyl)-thien-2-yl)-1-methyl-2-propenyl]-N-hydroxyurea
Step 1: 2-(4-fluorophenylmethyl)thiophene
A solution of thiophene (12.6 g, 0.15 mol) in a mixture of anhydrous ether (230 mL) and anhydrous THF (70 mL) was treated dropwise at 0° C. with a 2.5M solution of n-butyllithium in hexane (54.0 mL, 0.134 mol). The mixture was stirred at 0° C. for 1.5 hours and then transferred by cannula into a -78° C. solution of 4-fluorobenzylbromide (23.6 g, 0.125 mol) containing tetrakis(triphenylphosphine) palladium(O) (1.25 g) in anhydrous THF (200 mL). The reaction mixture was stirred for 17 hours at ambient temperature and then quenched with saturated aqueous NH 4 Cl solution (100 mL) and partitioned between ether and additional NH 4 Cl solution. The ether layer was dried over MgSO 4 , concentrated in vacuo and the residue subjected to vacuum distillation to give 19.4 g (81%) of 2-(4-fluorophenylmethyl)thiophene. b.p. 74°-83° C. at 0.6-0.7 mm of Hg.
Step 2: 2-iodo-5-(4-fluorophenylmethyl)thiophene
A mixture of 2-(4-fluorophenylmethyl)thiophene (3.85 g, 20.0 mmol), prepared as described in step 1, and N-iodosuccinimide (4.50 g, 20.0 mmol) in 1:1 chloroform-acetic acid (40 mL) was stirred at ambient temperature for 1 hour and then diluted with an equal volume of water. The organic layer was washed with saturated aqueous NaHCO 3 solution (2×50 mL), 10% aqueous sodium thiosulfate solution (2×50 mL) and once with brine. After drying over MgSO 4 , the organic layer was concentrated in vacuo to give 6.07 g (95%) of 2-iodo-5-(4-fluorophenylmethyl)thiophene as a gold colored oil.
Step 3. (R)-N-hydroxy-N-(3-butyn-2-yl)urea
To a solution of (S)-O-p-toluenesulfonyl-3-butyn-2-ol (11.2 g, 50.0 mmol), prepared by addition of p-toluenesulfonyl chloride and triethylamine to (S)-3-butyn-2-ol, in methanol (100 mL), was added 55% aqueous hydroxylamine (30 mL, 0.50 mol) and the reaction mixture was stirred at ambient temperature for 40 hours. The reaction mixture was cooled to 10° C. and concentrated HCl (50 mL) was added dropwise. The reaction mixture was concentrated in vacuo and the residue was partitioned between H 2 O (50 mL) and ethyl acetate (200 mL). The 2-phase mixture was cooled to 10° C. and taken to pH 8 with 50% aqueous NaOH solution (60 mL). After stirring for 15 min the layers were separated and the aqueous phase was extracted twice with 200 mL of ethyl acetate. The combined ethyl acetate extracts were cooled to 10° C. and a solution of KOCN (8.1 g, 0.10 mmol) in H.sub. 2 O (30 mL) was added, followed by dropwise addition of 11 mL of concentrated HCl, and the reaction mixture was stirred for 30 min. The ethyl acetate layer was separated and the aqueous layer was extracted twice with ethyl acetate. The combined organic layers were dried over MgSO 4 , filtered, and concentrated in vacuo to give 5.9 g (92% yield) of (R)-N-hydroxy-N-(3-butyn-2-yl)urea. mp 129° C. [α] D 24 =+53.3° (c=0.58, CH 3 OH). 1 H NMR (DMSO-d 6 , 300 MHz) 67 1.25 (d, 3H, J=7 Hz), 3.05 (d, 1H, J=2.5 Hz), 4.85 (dq, 1H, J=2.5, 7 Hz), 6.50 (br s, 2H), 9.24 (s, 1H). 13 CNMR (DMSO-d 6 , 75 MHz) δ18.43, 45.14, 72.81, 83.87, 161.51. IR (KBr) 3455, 3330, 3290, 3215, 1658, 1637, 1585 cm -1 . MS (DCI/NH 3 ) m/e 146 (M+NH 4 ) + , 163 (M+NH 4 .NH 3 ) + . Anal. Calc for C 5 H 8 N 2 O 2 : C, 46.87; H, 6.29; N, 21.86. Found: C, 46.78; H, 6.34; N, 21.72.
Step 4. (R)-N-{3-[5-(4-fluorophenylmethyl)thien-2-yl]-1-methyl-2-propynyl}-N-hydroxyurea
To a solution of 2-iodo-5-(4-fluorophenylmethyl)thiophene (5.30 g, 16.6 mmol), prepared as in step 2, in anhydrous DMF (5.0 mL) was added (R)-N-hydroxy-N-(3-butyn-2-yl)urea (2.12 g, 16.6 mmol), triphenylphosphine (84 mg, 0.32 mmol), bis(acetonitrile)palladium(II) chloride (40 mg, 0.16 mmol), copper (I) iodide (16 rag, 0.08 mmol), and diethylamine (5.6 ml). The mixture was stirred under nitrogen at ambient temperature for 22 hours and concentrated in vacuo at 32° C. The residue was subjected to chromatography on silica eluting with 2-7% MeOH in CH 2 Cl 2 , crystallization from ethyl acetate-hexane and trituration in CH 2 Cl 2 to afford (R)-N-{3-[5-(4-fluorophenylmethyl)thien-2-yl]-1-methyl-2-propynyl}-N-hydroxyurea as a cream-colored solid 0.94 g (18%). m.p. 135°-136° C.(dec). 1 H NMR (DMSO-d 6 , 300 MHz) δ1.32 (d, J=6.0 Hz, 3H), 4.11 (s, 2H), 5.10 (q, J=6.0Hz, 1H), 6.54 (s, 2H), 6.81 (d, J=3.0Hz, 1H), 7.08 (d, J=3.0Hz, 1H), 7.10-7.18 (m, 2H), 7.25-7.32 (m, 2H), 9.33 (s, 1H). MS (DCI/NH 3 ) m/e 319 (M+H) + . [a] D 23 ° =+47.8° (C=1, MeOH). Anal calcd for C 16 H 15 FN 2 O 2 S: C, 60.36; H, 4.75; N, 8.80. Found: C, 60.31; H, 4.79; N, 8.50.
Step 5: Z-(R)-N-[3-(5-(4-Fluorophenylmethyl)-thien-2-yl )-1-methyl-2-propenyl]-N-hydroxyurea
A solution of (R)-N-{3-[5-(4-fluorophenylmethyl)thien-2-yl]-1-methyl-2-propynyl}-N-hydroxyurea (0.50 g, 1.57 mmol), prepared as in step 4, quinoline (0.25 mL, 2.11 mmol), and 5% palladium on calcium chloride poisoned with lead (0.025 g) in acetone (15 mL) was allowed to stir under hydrogen (atmospheric pressure) for 24 hours. The solution was filtered through celite and solvents removed in vacuo. The resulting oil was taken up in ethyl acetate (50mL) and washed with aqueous 1M H 3 PO 4 (3×25 mL) and aqueous NaHCO 3 (3×25 mL). The solution was dried (MgSO 4 ) after which the solvent was evaporated to yield a yellow oil. The residue was purified by chromatography on silica gel (50% ethyl acetate/hexane/1% acetic acid). The resulting solid was crystallized from hot ethyl acetate/hexane to yield 0.145g (29%) of Z-N-[3-(5-(4-Fluorophenylmethyl)-thien-2-yl)-1-[R]-methyl-2-propenyl]-N-hydroxyurea. m.p. 123°-4° C., MS. (DCI/NH 3 ) m/e 321 (M+H) + , 338 (M+NH 4 ) + . 1 H NMR (DMSO-d6, 300 MHz) δ1.16 (d,J=6.3 Hz, 3H), 4.1 (s, 2H), 5.25 (m, 1H), 5.67 (rid, J=9.0, 11.7 Hz, 1H), 6.35 (s, 2H), 6.43 (d, J=11.7 Hz, 1H), 6.83 (d, J=3.6 Hz, 1H), 6.94 (d, J=3.6 Hz, 1H), 7.13 (m, 2H), 7.32 (m, 2H), 9.18 (s, 1H). Anal calcd for C 17 H 17 FN 2 O 2 S: C, 59.98; H, 5.35; N, 8.74. Found C, 59.79; H, 5.25; N, 8.71.
EXAMPLE 2
Preparation of E-(R)-N-[3-(5-(4-Fluorophenylmethyl)-thien-2-yl)-1-methyl-2-propenyl]-N-hydroxyurea
To a solution of (R)-N-{3-[5-(4-fluorophenylmethyl)thien-2-yl]-1-methyl-2-propynyl}-N-hydroxyurea (0.316g, 1.05 mmol), prepared as in Example 1, step 4, in THF (8 mL) at -70° C. was added DIBAL (5.23 mL, 5.25 mmol). The reaction was slowly allowed to warm to ambient temperature over 17 hours. The reaction was quenched into an aqueous 1M H 3 PO 4 solution and extracted with ethyl acetate. The combined organic layers were washed with aqueous NaHCO 3 , dried (MgSO 4 ) and evaporated. The residue was purified by chromatography on silica gel (50% ethyl acetate/hexanes/1% acetic acid). The resulting solid was crystallized from hot ethyl acetate/hexanes to yield 0.063 g (20% ) of E-N-[3-(5-(4-Fluorophenylmethyl)-thien-2-yl)-1-(R)-methyl-2-propenyl]-N-hydroxyurea. m.p. 143°-4° C). MS (DCI/NH 3 ) m/e 321 (M+H) + , 338 (M+NH 4 ) + . 1 H NMR (DMSO-d6, 300 MHz) δ1.17(d, J=7.2 Hz, 3H), 4.08 (s, 2H), 4.73 (m, 1H), 5.88 (dd, J=6.3, 15.6 Hz, 1H), 6.33 (s, 2H), 6.55 (d, J=15.6 Hz, 1H), 6.77 (d, J=4.2 Hz, 1H), 6.83 (d, J=4.2 Hz, 1H), 7.12 (m, 2H), 7.29 (m, 2H), 9.02 (s, 1H). Anal Calcd for C 17 H 17 FN 2 O 2 S: C, 59.98; H, 5.35; N, 8.74. Found C, 60.15; H, 5.11; N, 8.75.
EXAMPLE 3
Preparation of Z-N-[3-(5-(4-Fluorophenylmethyl)-thien-2-yl)-1-methyl-2-propenyl]-N-hydroxyurea
Step 1: N,O-bis(phenoxycarbonyl)-N-(3-butyn-2-yl)hydroxylamine
To a 0° C. solution in THF (200 mL) of 3-butyn-2-ol (3.00 g, 42.9 mmol), N,O-bis(phenoxycarbonyl)hydroxylamine (11.7 g, 42.9 mmol), prepared according to the method of Stewart and Brooks, J. Org. Chem. 1992, 57, 5020, and triphenylphosphine (11.7 g, 42.9 mmol), was added dropwise diethylazodicarboxylate (7.40 g, 42.8 mmol). The reaction mixture was stirred for 2 hours at 0°-5° C. and then was concentrated almost to dryness. The residue was diluted with ethyl acetate, the solids were filtered off, and the filtrate was concentrated in vacuo. Chromatography on silica gel (5% ethyl acetate, pentane) provided N,O-bis(phenoxycarbonyl)-N-(3-butyn-2-yl)hydroxylamine (12.3 g, 88%).
Step 2: N-(3-butyn-2-yl)N-hydroxyurea
A mixture of N,O-Bis(phenoxycarbonyl)-N-(3-butyn-2-yl)hydroxylamine (3.14 g,9.7 mmol), methanol (20 mL), and ammonium hydroxide (20 mL) was stirred for 17 hours at ambient temperature. The reaction mixture was concentrated in vacuo and the residue was dissolved in ethyl acetate. The organic solution was washed with brine, dried over MgSO 4 , filtered, and concentrated. Chromatography on silica gel (2% methanol, methylene chloride) afforded N-(3-butyn-2-yl)N-hydroxyurea (340 rag, 28%). 1 H NMR (DMSO-26, 300 MHz) δ1.25 (d, 3H, J=7.5 Hz), 3.05 (d, 1H, J=3.0 Hz), 4.85 (dq, 1H, J=7.5, 3.0 Hz), 6.50 (br s, 1H), 9.25 (S, 1H). MS (DCI/NH 3 ) m/e 129 (M+H) + , 146 (M+NH 4 ) + . Anal calcd for C 5 H 8 N 2 O 2 : C, 46.87; H, 6.29; N, 21.86. Found: C, 47.03; H, 6.27; N, 21.98.
Step 3. N-{3-[5-(4-fluorophenylmethyl)thien-2-yl]-1-methyl-2-propynyl}-N-hydroxyurea
The desired compound is prepared according to the method of Example 1, step 4, except substituting N-(3-butyn-2-yl)N-hydroxyurea, prepared as in step 2, for (R)N-(3-butyn-2-yl)N-hydroxyurea.
Step 4: Z-N-[3-(5-(4-Fluorophenylmethyl)-thien-2-yl)-1-methyl-2-propenyl]-N-hydroxyurea
Racemic Z-N-[3-(5-(4-Fluorophenylmethyl)-thien-2-yl)-1-methyl-2-propenyl]-N-hydroxyurea is prepared according to the method of Example 1 ,step 5, except substituting N-{3-[5-(4-fluorophenylmethyl)-thien-2-yl]-1-methyl-2-propynyl}-N-hydroxyurea, prepared as in step 3, for (R) N-{3-[5-(4-fluorophenylmethyl)-thien-2-yl]-1-methyl-2-propynyl}-N-hydroxyurea.
EXAMPLE 4
Preparation of E-N-[3-(5-(4-Fluorophenylmethyl)-thien-2-yl)-1-methyl-2-propenyl]-N-hydroxyurea
The desired compound is prepared according to the method of Example 2, except substituting N-{3-[5-(4-fluorophenylmethyl)-thien-2-yl]-1-methyl-2-propynyl}-N-hydroxyurea, prepared as in Example 3, step 2, for (R) N-{3-[5-(4-fluorophenylmethyl)-thien-2-yl]-1-methyl-2-propynyl}-N-hydroxyurea.
EXAMPLE 5
Preparation of Z-N-[3-(5-(4-Fluorophenylmethyl)-fur-2-yl)-1-methyl-2-propenyl]-N-hydroxyurea
The desired compound is prepared according to the method of Example 1, except substituting furan for thiophene, and substituting N-(3-butyn-2-yl)N-hydroxyurea, prepared as in Example 3, step 2, for (R) N-(3-butyn-2-yl)N-hydroxyurea.
EXAMPLE 6
Preparation of E-N-[3-(5-(4-Fluorophenylmethyl)-fur-2-yl)-1-methyl-2-propenyl]-N-hydroxyurea
The desired compound is prepared according to the method of Example 2, except substituting furan for thiophene, and substituting N-(3-butyn-2-yl)N-hydroxyurea, prepared as in Example 3, step 2, for (R) N-(3-butyn-2-yl)N-hydroxyurea.
EXAMPLE 7
Preparation of Z-(R)-N-{3-[5-(4-fluorophenylmethyl)thiazo-2-yl]-1-methyl-2-propenyl}-N-hydroxyurea
The desired compound is prepared using the procedures described in Example 11, except substituting 5-(4-fluorophenylmethyl)thiazole for 2-(4-fluorophenylmethyl)thiophene.
EXAMPLE 8
Preparation of E-(R)-N-{3-[5-(4-fluorophenylmethyl)thiazo-2-yl]-1-methyl-2-propenyl}-N-hydroxyurea
The desired compound is prepared according to the method of Example 2, except substituting (R)-N-{3-[5-(4-fluorophenylmethyl)thiazo-2-yl]-1-methyl-2-propynyl}-N-hydroxyurea, prepared as in Example 7, for (R)-N-{3-[5-(4-fluorophenylmethyl)thien-2-yl]-1-methyl-2-propynyl}-N-hydroxyurea.
EXAMPLE 9
Preparation of Z-(R)-N-[3-(5-(4-chlorophenylmethyl)-thien-2-yl)-1-methyl-2-propenyl]-N-hydroxyurea
Step 1: 4-chlorobenzyl bromide
To a suspension of 4-chlorobenzyl alcohol (14.26 g, 100 mmol) in CH 2 Cl 2 (40 mL) at ambient temperature was added added dropwise a solution of PBr 3 in CH 2 Cl 2 (1.0M, 32 mL, 32 mmol). The reaction mixture was stirred for 72 hours at ambient temperature and then was poured slowly onto ice. The layers were separated and the organic phase was dried over MgSO 4 , filtered, and concentrated in vacuo to give 4-chlorobenzyl bromide (19.76 g) as a colorless solid.
Step 2: 2-(4-chlorophenylmethyl)thiophene
The desired compound was prepared according to the method of Example 1, step I, except substituting 4-chlorobenzyl bromide, prepared as in step 1, for 4-fluorobenzyl bromide, and using THF instead of the ether/THF mixture.
Step 3: 2-iodo-5-(4-chlorophenylmethyl)thiophene
The desired compound was prepared according to the method of Example 1, step 2, except substituting 2-(4-chlorophenylmethyl)thiophene for 2-(4-fluorophenylmethyl)thiophene.
Step4: (R)-N-{3-[5-(4-chlorophenylmethyl)thien-2-yl]-1-methyl-2-propynyl}-N-hydroxyurea
The title compound was prepared using the procedures described in Example 1, step 4, except substituting 2-iodo-5-(4-chlorophenylmethyl)thiophene, prepared as in step 3, for 2-iodo-5-(4-fluorophenylmethyl)thiophene. mp 132°-13420 C. 1 H NMR (DMSO-d 6 ) δ1.33 (d, J=7 Hz, 3H), 4.12 (s, 2H), 5.11 (q, J=7 Hz, 1H), 6.50 (bs, 2H), 6.82 (d, J=4 Hz, 1H), 7.08 (d, J=4 Hz, 1H), 7.28 (m, 2H), 7.37 (m, 2H), 9.30 (s, 1H). MS (DCI/NH 3 ) m/e 352 (M+NH 4 ) + , 335 (M+H) + , 259. Anal calcd for C 16 H 15 N 2 O 2 S: C, 57.40; H, 4.52; N, 8.37. Found: C, 57.46; H, 4.26; N, 8.40.
Step 5: Z-(R)-N-[3-(5-(4-chlorophenylmethyl)-thien-2-yl)-1-methyl-2-propenyl]-N-hydroxyurea
The desired compound is prepared according to the method of Example 1, step 5, except substituting (R)-N-{3-[5-(4-chlorophenylmethyl)thien-2-yl]-1-methyl-2-propynyl}-N-hydroxyurea, prepared as in step 4, for (R)-N-{3-[5-(4-fluorophenylmethyl)thien-2-yl]-1-methyl-2-propynyl}-N-hydroxyurea.
EXAMPLE 10
Preparation of Z-(R)-N-(3-(5-(3-pyridylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea
Step 1: 2-(3-pyridylhydroxymethyl)thiophene
To a solution of 3-pyridinecarboxaldehyde (5.0 mL, 53 mmol) in THF at -78° C. was added 2-thienyllithium (1.0M in THF, 64 mL, 64 mmol) and the reaction mixture was stirred for 2 hours at -78° C. The reaction mixture was quenched with saturated aqueous NH 4 Cl and extracted with ether. The organic phase was dried over MgSO 4 , filtered, and concentrated in vacuo. Chromatography on silica gel (5%, then 10% methanol/CHCl 3 ) gave 2-(3-pyridylhydroxymethyl)thiophene (6.30 g, 62% yield).
Step 2: 2-(3-pyridylmethyl)thiophene
To a solution of 2-(3-pyridylhydroxymethyl)thiophene (8.82 g, 46.2 mmol), prepared as in step 1, in acetic acid (50 mL) was added tin(H)chloride dihydrate (22.9 g, 101 mmol) and HCl gas was bubbled through the reaction mixture for about 10 min. The reaction mixture was stirred for 1.5 hours at ambient temperature, and the liquid was decanted, concentrated in vacuo to a volume of about 10 mL, and poured into H 2 O. The aqueous solution was made basic by the slow addition of saturated aqueous NaHCO 3 and extracted with ethyl acetate/ether. The organic phase was dried over MgSO 4 , filtered, and concentrated in vacuo. Chromatography on silica gel (5% methanol/CHCl 3 ) gave 2-(3-pyridylmethyl)thiophene (2.63 g).
Step 3: Z-(R)-N-(3-(5-(3-pyridylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea
The desired compound is prepared according to the method of Example 1, steps 2-5, except substituting 2-(3-pyridylmethyl)thiophene, prepared as in step 2, for 2-(4-fluorophenylmethyl)thiophene.
EXAMPLE 11
Preparation of Z-(R)-N-(3-(5-(4-pyridylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea
Step 1: 2-iodo-5-(4-pyridylhydroxymethyl)thiophene
To a solution of LDA (11 mmol) in THF at -78° C. was added 2-iodothiophene (2.1 g, 10 mmol). After stirring for 0.5 hours at -78° C., a solution of 4-pyridinecarboxaldehyde (1.07 g, 10 mmol) in THF (10 mL) was added dropwise and the reaction mixture was warmed slowly to ambient temperature and stirred for 16 hours. The reaction was quenched with saturated aqueous NH 4 Cl, diluted with H 2 O, and extracted twice with ethyl acetate. The combined organic layers were dried over MgSO 4 , filtered, and concentrated in vacuo. Chromatography on silica gel (80% ethyl acetate/hexanes)provided 2-iodo-5-(4-pyridiylhydroxymethyl)thiophene (1.39 g, 40% yield) as a tan solid.
Step 2: 2-iodo-5-(4-pyridylmethyl)thiophene
A suspension of 2-iodo-5-(4-pyridylhydroxymethyl)thiophene (0.65 g, 2.05 mmol) and tin(II) chloride dihydrate (1.01 g, 4.51 mmol) in acetic acid (5 mL) was treated with HCl gas for 10 rain and stirred for 2 hours at ambient temperature. The reaction mixture was poured into H 2 O, neutralized with 10% aqueous NaOH, and extracted twice with ethyl acetate. The combined organic layers were washed with H 2 O, dried over MgSO 4 , filtered, and concentrated in vacuo. Chromatography on silica gel provided 2-iodo-5-(4-pyridylmethyl)thiophene (0.22 g, 36% yield) as a white solid.
Step 3: Z-(R)-N-(3-(5-(4-pyridylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea
The desired compound is prepared according to the method of Example 1, steps 4 and 5, except substituting 2-iodo-5-(4-pyridylmethyl)thiophene, prepared as in step 2, for 2-iodo-5-(4-fluorophenylmethyl)thiophene.
EXAMPLE 12
Preparation of Z-(R)-N-(3-(5.-(2-pyridylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea
The desired compound is prepared according to the method of Example 10, except substituting 2-pyridinecarboxaldehyde for 3-pyrdinecarboxaldehyde.
EXAMPLE 13
Preparation of Z-(R)-N-(3-(5-(thien-2-ylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea
The desired compound is prepared according to the method of Example 1, steps 2-5, except substituting 2-(thien-2-ylmethyl)thiophene for 2-(4-fluorophenylmethyl)thiophene.
EXAMPLE 14
Preparation of Z-(R)-N-(3-(5-(2-naphthylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea
Step 1: 2-iodo-5-(2-naphthylmethyl)thiophene
The desired compound was prepared according to the method of Example 11, step 1, except substituting 2-(bromomethyl)naphthylene for 4-pyridinecarboxaldehyde.
Step 2: Z-(R)-N-(3-(5-(2-naphthylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea
The desired compound is prepared according to the method of Example 1, steps 4 and 5, except substituting 2-iodo-5-(2-naphthylmethyl)thiophene, prepared as in step 1, for 2-iodo-5-(4-fluorophenylmethyl)thiophene.
EXAMPLE 15
Preparation of Z-(R)-N-(3-(5-(2,quinolylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea
The desired compound is prepared according to the method of Example 11, except substituting 2-quinolinecarboxaldehyde for 4-pyridinecarboxaldehyde.
EXAMPLE 16
Preparation of Z-(R)-N-(3-(5-(4-fluorophenylethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea
The desired compound is prepared according to the method of Example 9, except substituting 4-fluorophenethyl alcohol for 4-chlorobenzyl alcohol.
EXAMPLE 17
Preparation of Z-(R)-N-(3-(4-(4-fluorophenylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea
Step 1: 2-iodo-4-(4-fluorophenylmethyl)thiophene
To a solution of LDA (3.67 mmol) in THF at -78° C. was added a solution of 3-(4-fluorophenylmethyl)thiophene (640 rag, 3.33 mmol), prepared as in Example 35, step 1, and the reaction mixture was stirred for 25 min. A solution of I 2 (1.01 g, 4.00 mmol) in THF was added and the cold bath was removed. The reaction mixture was warmed to ambient temperature, quenched with saturated aqueous NH 4 Cl, and extracted with ether. The organic phase was washed with 1N aqueous H 3 PO 4 , saturated aqueous NaHCO 3 , saturated aqueous Na 2 S 2 O 3 , and brine, dried over MgSO 4 , filtered, and concentrated in vacuo to give 928 mg of 2-iodo-4-(4-fluorophenylmethyl)thiophene which was used without further purification.
Step 2:Z-(R)-N-(3-(4-(4-fluorophenylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea
The desired compound is prepared according to the method of Example 1, steps 4 and 5, except substituting 2-iodo-4-(4-fluorophenylmethyl)thiophene, prepared as in step 1, for 2-iodo-5-(4-fluorophenylmethyl)thiophene.
EXAMPLE 18
Preparation of Z-(R)-N-(3-(5-(4-biphenylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea
Step 1: 2-iodo-5-(4-biphenylhydroxymethyl)thiophene
The desired compound was prepared according to the method of Example 11, step 1, except substituting 4-biphenylcarboxaldehyde for 4-pyridinecarboxaldehyde.
Step 2: 2-iodo-5-(4-biphenylmethyl)thiophene
To a solution of 2-iodo-5-(4-biphenylhydroxymethyl)thiophene (1.96 g, 5.0 mmol), prepared as in step 1, in dichloroethane (30 mL), was added sodium cyanoborohydride (2.2 g, 35 mmol), and ZnI 2 (2.0 g, 6.3 mmol). The reaction mixture was stirred for 6 hours at ambient temperature and then was filtered through a pad of celite. The filter cake was rinsed with CH 2 Cl 2 and hexane, and the filtrate was concentrated in vacuo. Pure 2-iodo-5-(4-biphenylmethyl)thiophene (1.7 g) was obtained by chromatography on silica gel (3% ethyl acetate/hexane) and recrystallization from hexane/ethyl acetate.
Step 3: Z-(R)-N-(3-(5-(4-biphenylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea
The desired compound is prepared according to the method of Example 1, steps 4 and 5, except substituting 2-iodo-5-(4-biphenylmethyl)thiophene, prepared as in step 2, for 2-iodo-5-(4-fluorophenylmethyl)thiophene.
EXAMPLE 19
Preparation of Z-(R)-N-(3-(5-(thiazol-4-ylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea
Step 1: 2-(thiazo-4-ylmethyl)thiophene
To a suspension of 4-chloromethylthiazole hydrochloride (3.41 g, 20.0 mmol) in THF (50 mL) was added triethylamine (3.04 g, 30.0 mmol) in one portion and the suspension was stirred for 2 hours at ambient temperature. The solid was then filtered off and rinsed with THF. The combined filtrate and washings were cooled to -78° C. and a solution of 2-thienyllithium in THF (20.0 mmol), prepared as in Example 12, step 1, was added over 10 min. The reaction mixture was stirred for 1 hour at -78° C. and then 17 hours at ambient temperature. The reaction was quenched with saturated aqueous NH 4 Cl and diluted with ether. The organic phase was separated, dried over MgSO 4 , filtered, and concentrated in vacuo to give a maroon-colored oil. Chromatography on silica gel provided 2-(thiazo-4-ylmethyl)thiophene (0.325 g).
Step 2: Z-(R)-N-(3-(5-(thiazo-4-ylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea
The desired compound is prepared according to the method of Example 1, steps 2-5, except substituting 2-(thiazo-4-ylmethyl)thiophene, prepared as in step 1, for 2-(4-fluorophenylmethyl)thiophene.
EXAMPLE 20
Preparation of Z-(R)-N-(3-(5-(benzo[b]thien-2-ylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea
The desired compound is prepared according to the method of Example 18, except substituting benzo[b]thiophene-2-carboxaldehyde for 4-biphenycarboxaldehyde.
EXAMPLE 21
Preparation of Z-(R)-N-(3-(5-(thiazo-2-ylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea
Step 1: 2-thiopheneacetamide
To a mixture of concentrated NH 4 OH (100 mL) and ice was added 2-thiopheneacetyl chloride (13.0 g, 80.9 mmol). The desired compound crystallized from the reaction mixture. Recrystallization from hot water gave 2-thiopheneacetamide (8.08 g, 64% yield) as white crystals. mp 146°-147° C.
Step 2: 2-thiophenethioacetamide
To a solution in THF (20(3 mL) of 2-thiopheneacetamide (4.04 g, 28.6 mmol), prepared as in step 1, was added P 4 S 10 (12,7 g, 28.6 mmol), and the vigorously stirred reaction mixture was placed in a Bransonic 221 bath and sonicated with ultrasound for 30 min. The reaction mixture was filtered and the filtrate was concentrated in vacuo. The crude product was taken up in CH 2 Cl 2 and decanted from the solid residue. Pure 2-thiophenethioacetamide (2.45 g, 54% yield) was obtained by chromatography on silica gel (CH 2 Cl 2 ).
Step 3: 2-(thiazo-2-ylmethyl)thiophene
A solution of 2-thiophenethioacetamide (3.35 g, 21.3 mmol) in benzene (125 mL) was heated at reflux while 50% aqueous chloroacetaldehyde (6.62 g, 42.0 mmol) was added dropwise. The reaction mixture was heated for 2.5 hours at reflux, then left standing at -20° C. for 17 hours. After warming to reflux and heating for another hour, the reaction mixture was cooled to ambient temperature and the layers were separated. The organic layer was concentrated in vacuo to give 3.08 g of a dark oil. Chromatography on silica gel (CH 2 Cl 2 ) gave 2-(thiazo-2-ylmethyl)thiophene (1.24 g). The aqueous phase was treated with decolorizing carbon and filtered. The filtrate was taken to pH 11 with 6N aqueous NaOH and extracted twice with ether. The combined ether layers were dried over KOH, filtered, and concentrated in vacuo to to give an additional 1.02 g of 2-(thiazo-2-ylmethyl)thiophene (total yield 2.26 g, 58%).
Step 4: Z-(R)-N-(3-(5-(thiazo-2-ylmethyl)thien-2-yl)-1-methyl-2-propenyl)-N-hydroxyurea
The desired compound is prepared according to the method of Example 1, steps 2-5, except substituting 2-(thiazo-2-ylmethyl)thiophene, prepared as in step 3, for 2-(4-fluorophenylmethyl)thiophene.
EXAMPLE 22
Preparation of Z-N-(3-(5-(4-fluorophenylmethyl)thien-2-yl)-2-propenyl)-N-hydroxyurea
The desired compound is prepared according to the method of Example 3, except substituting propargyl alcohol for 3-butyn-2-ol.
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Compounds of the structure ##STR1## wherein Z is selected from optionally substituted thienyl, thiazolyl, oxazolyl and furyl are potent inhibitors of lipoxygenase enzymes and thus inhibit the biosynthesis of leukotrienes. These compounds are useful in the treatment or amelioration of allergic and inflammatory disease states.
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CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a Continuation in Part of co-pending U.S. patent application Ser. No. 13/302,554 filed on Nov. 22, 2011, entitled “TONG ASSEMBLY FOR MANIPULATING A TUBULAR.” This reference is hereby incorporated in its entirety.
FIELD
The present embodiments generally relate to a tong assembly for use in make-up or break-out of a tubular.
BACKGROUND
A need exists for a tong assembly for making-up or breaking-out a tubular that can be used with limited training or expertise.
A further need exists for a tong assembly that can be used to automatically break-out or make-up tubulars with minimal risk and minimal human interaction.
A further need exists for a tong assembly that does not require readjustment during the make-up or break-out procedure due to rolling off center of the tubular when the jaw connects with the tubular.
The present embodiments meet these needs.
BRIEF DESCRIPTION OF THE DRAWINGS
The detailed description will be better understood in conjunction with the accompanying drawings as follows:
FIG. 1 depicts an exploded view of an arm frame according to one or more embodiments.
FIG. 2A depicts a top view of a top plate of the arm frame according to one or more embodiments.
FIG. 2B depicts a bottom view of a bottom plate of the arm frame according to one or more embodiments.
FIG. 3A depicts a perspective view of a two tong die jaw usable with the arm of according to one or more embodiments.
FIG. 3B depicts a perspective view of a two tong die jaw with tapered jaw tail and latching member usable with the arm according to one or more embodiments.
FIG. 3C shows a side view of a tail hole according to one or more embodiments.
FIG. 4 depicts an exploded view of a two tong die jaw according to one more embodiments.
FIG. 5A depicts a side view of an exemplary tong die according to one or more embodiments.
FIG. 5B depicts a cut view of the exemplary tong die of FIG. 5A .
FIG. 6 is an exploded view of the tong assembly with two chain assemblies, two jaws, an arm frame, two chain cylinders, and one break-out/make-up cylinder and break-out/make-up body according to one or more embodiments.
FIG. 7 is a detail of a chain assembly according to one or more embodiments.
FIG. 8 is a detail of a chain link usable in a chain assembly according to one or more embodiments.
The present embodiments are detailed below with reference to the listed Figures.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Before explaining the present apparatus in detail, it is to be understood that the apparatus is not limited to the particular embodiments and that it can be practiced or carried out in various ways.
The present embodiments generally relate to a tong assembly with a break-out/make-up arm, which can be spaced apart from a backup arm. The break-out/make-up arm, the backup arm, or combinations thereof, can engage a tubular.
The tong assembly can have an automated make-up or break-out procedure, such as a remote control, which actuates the cylinders, eliminating the loss of extremities due to injury from manual tongs.
The tong assembly can prevent work slows by replacing manual tongs, leading to overall employment growth. The tong assembly can prevent layoffs or employee replacement by preventing injuries that can require hospitalization.
The tong assembly can have a design which internally dissipates energy, aiding in the prevention of violent energy releases that can lead to oil spills.
The tong assembly can be extremely portable and require little extra equipment, which can allow water well drilling to be done safely by low skill individuals in remote towns and villages.
The tong assembly can have a specialized design, which can prevent the use of dangerous equipment, which is not designed for the purpose of make-up or break-out, from being used, such as overhead cranes with cables.
The invention provides a seamless, effortless switch for a tong assembly from breaking-out to making-up of tubulars.
The present embodiments do not require a machine set up change when changing from a break-out operational mode to a make-up operational mode or vice versa.
This invention allows effortless and immediate change from making-up to breaking-out of a pipe instantly, from a tubular make-up orientation (a forward rotating direction) to a tubular break-out orientation (a reverse rotating direction from the make-up rotational direction).
Typical tong assemblies may require an hour or more to set up the machine for making-up or breaking-out of tubulars. This invention enables a change from make-up to break-out of tubulars for drill pipe in a drill string, in less than 5 minutes.
Turning now to the Figures, FIG. 1 shows an arm frame 56 for a break-out/make-up arm for a tong assembly.
The arm frame 56 can have a top plate 60 , which can have a top fastening hole 78 for receiving a jaw retaining pin 164 .
The top plate 60 can have a top reducer hole 81 for retaining added parts to the arm frame, such as accessories like a reducer, to accommodate a smaller outer diameter pipe.
Spaced apart from the top reducer hole 81 can be a first top chain connection hole 602 a and a second top chain connection hole 607 a.
A break-out/make-up cylinder connection hole 111 a can engage a first cylinder connecting pin 10 . The first cylinder connecting pin 10 can hold a break-out/make-up cylinder.
Usable break-out/make-up cylinders can be hydraulic and self-contained units, in embodiments.
In embodiments, the break-out/make-up cylinder can perform two different activities. The break-out/make-up cylinder can both make-up and break-out drill pipe using only one configuration to do both activities.
In embodiments, once positioned, the dual purpose break-out/make-up cylinder can handle forward and reverse stroking.
In embodiments, when stroking out, the break-out/make-up cylinder can perform a break-out/make-up stroke for breaking out a first tubular to any kind of connection or for breaking-out a first tubular to a second tubular.
In embodiments, when stroking out, the break-out/make-up cylinder can apply up to 4000 psi, or pressure as needed, to break-out two tubulars or a tubular with a connection.
In embodiments, a dual purpose break-out/make-up cylinder can be used with a rod that extends and retracts hydraulically.
In embodiments, for break-out, the dual purpose break-out/make-up cylinder can use as much psi as needed in order to break a pipe joint.
In embodiments, in make-up operational mode, the dual purpose break-out/make-up cylinder can supply a controlled pressure in order to limit excessive torque applied to drill pipe as needed or as specified by the manufacturer of a pipe joint.
By controlling pressure, the amount of torque that needs to be applied to the drill pipe is controlled. The apparatus prevents over torqueing of the drill pipe and prevents shearing of drill pipe threads.
A chain cylinder connection hole 112 a can engage a second cylinder connecting pin 11 for holding a chain cylinder.
The break-out/make-up cylinder connection hole 111 a and the chain cylinder connection hole 112 a can range in diameter from 0.50 inches to 3 inches.
In embodiments, the top plate 60 can have a first concave edge 603 a configured to accommodate a chain link. The first concave edge 603 a can match a chain link radius of a chain assembly.
The top plate can have a second concave edge 604 a configured to accommodate larger radius or larger outer diameters of tools than the maximum capacity of the first concave edge 603 a of the top plate. The top plate can have a rod rest 126 a.
In embodiments, the top plate can have a jaw resting edge 127 a . The jaw resting edge 127 a can be configured to support a jaw 12 .
The top plate can receive, through the first top chain connection hole 602 a , a first chain connection pin 181 a for connecting between the top plate to the chain assembly.
The top plate can receive, through the second top chain connection hole 607 a , a second chain connection pin 181 b for connecting between the top plate and the chain assembly.
A bottom plate 84 can have matching aligned holes with the top plate 60 . The bottom plate can be mounted to align with the top plate.
Mounted between the top and bottom plates can be side support plates 106 a , 106 b , 106 c , 106 d and 106 e . Side support plate 106 e can support the first and second chain connection pins 181 a and 181 b , enabling a load transfer from the chain connection pins.
The plurality of side support plates can connect the top and bottom plates. In an embodiment, the side support plates can be welded to the top and bottom plates.
In embodiments, the side support plates can be from 1 inch to 3 inches in height. The side support plates can be from 0.5 inches to 1 inch in thickness. The side support plates can be formed from steel.
In embodiments, the bottom plate 84 can have a bottom fastening hole 100 , which aligns with the top fastening hole 78 .
In embodiments, the bottom plate can also have a bottom reducer which aligns with the top reducer hole.
In embodiments, the bottom plate 84 can have a first bottom chain connection hole 602 b and a second bottom chain connection hole 607 b . The first and second bottom chain connection holes can align with the first and second top chain connection holes of the top plate.
The bottom plate can have a jaw resting edge 127 b . The jaw resting edge 127 b and the jaw resting edge 127 a can both be configured to support the jaw 12 .
The bottom plate can have a pair of load support walls 108 and 109 .
In embodiments, the load support walls can be mounted to the bottom plate in parallel with each other.
In embodiments, the load support walls can be mounted in a tapered configuration that tapers from a large end at the jaw resting edge to a more narrow location interior of the arm frame.
In embodiments, the load support walls and the spacing bars can all be the same height.
The pair of load support walls can create a pocket between the top and bottom plates. The pocket can have the top and bottom fastening holes and the jaw retaining pin extend through it. The jaw retaining pin 164 can hold the tail of the jaw through a tail hole 608 between the top and bottom plates.
The bottom plate can include a break-out/make-up cylinder connection hole 111 b , a chain cylinder connection hole 112 b , and rod rest 126 b.
The first bottom chain connection hole 602 b can be formed within a first concave edge 603 b.
The second bottom chain connection hole 607 B can be formed within a second concave edge 604 b.
FIG. 2A shows a top view of the top plate according to one or more embodiments.
The top plate 60 is shown with the top fastening hole 78 , the break-out/make-up cylinder connection hole 111 a , the chain cylinder connection hole 112 a , a top reducer hole 81 , and a notch 125 a adjacent the top reducer hole on the same side as the chain cylinder connection hole.
The notch 125 a can be configured to accommodate a body of the chain cylinder.
In currently available systems, when a chain cylinder body rests in contact with the arm frame, the cylinder rod of the chain cylinder can be pulled toward the arm frame improperly, creating a side load that will cause the rod to pull inward toward the arm frame and bend or break.
In the present embodiments, the notch 125 a formed in the top plate and the corresponding notch in the bottom plate are configured so that the cylinder rod rests on rod rest 126 a of the top plate and the rod rest of the bottom plate.
The notches enable the chain cylinder to be larger in size than those usable in currently available tong assemblies, providing a chain cylinder that generates a stronger gripping force.
The notches also enable the chain cylinder to operate with the chain assembly to handle smaller outer diameter tubular joints. This notch is a major benefit of this invention. The notch enables this tong assembly to be more versatile than other tong assemblies without requiring additional parts and without requiring additional time for tong assembly set up.
The notch enables the apparatus to have a chain cylinder that is safer than other tong assemblies because the configuration reduces the possibility of rod damage.
The top plate is shown with the jaw resting edge 127 a formed on a side at a right angle to the side with the rod rest 126 a.
The top plate is shown with the first top chain connection hole 602 a formed within the first concave edge 603 a and the second top chain connection hole 607 a formed within the second concave edge 604 a.
FIG. 2B shows a bottom view of the bottom plate according to one or more embodiments.
The bottom plate 84 is shown with the bottom fastening hole 100 , the break-out/make-up cylinder connection hole 111 b , and the chain cylinder connection hole 112 b.
The bottom plate can have a notch 125 b , which can be identical to the notch in the top plate.
The bottom plate is also shown with a bottom reducer hole 82 , the rod rest 126 b , the jaw resting edge 127 b formed on a side at a right angle to the side of the bottom plate with the rod rest, the first bottom chain connection hole 602 b formed within the first concave edge 603 b , and the second bottom chain connection hole 607 b formed within the second concave edge 604 b.
FIG. 3A depicts a perspective view of the jaw according to one or more embodiments.
The jaw 12 can have a jaw head 13 and a jaw tail 606 . The jaw head can be wider than the jaw tail.
In embodiments, the jaw head 13 can have two tong die grooves 18 a and 18 b.
The jaw head 13 can have a face 16 formed between the two tong die grooves.
The jaw head 13 can have a first sloped edge 14 a and a second sloped edge 14 b forming the first tong die groove 18 a.
The jaw head 13 can have a third sloped edge 14 c and a fourth sloped edge 14 d forming the second tong die groove 18 b.
The tong dies can be removably inserted in the tong die grooves.
The jaw head can have a load surface 19 opposite the face 16 for engaging the jaw resting edges of the arm frame.
Each tong die groove can have a holding means to assist in holding the tong die into the tong die groove. The holding means can be a detent that fits into a detent hole 99 a in the tong die groove 18 a and a similar detent hole 99 b in the tong die groove 18 b.
The jaw tail 606 can extend from the jaw head 13 opposite the face 16 for insertion between the top and bottom plates in the pocket.
The jaw tail 606 is shown with the tail hole 608 for receiving the jaw retaining pin.
The jaw retaining pin can be inserted through the top fastening hole and the bottom fastening hole simultaneously while engaging the tail hole to hold the tail into the pocket when the arm is assembled.
The jaw tail can have an outer side 611 configured for contacting simultaneously against load support walls in the pocket between the top and bottom plates.
The first damper cavity 610 can surround a first side of the tail hole 608 on a first side.
A second damper cavity can surround a second side of the tail hole. A damper can be inserted into each damper cavity.
FIG. 3B depicts a perspective view of the jaw 12 with a tapered jaw tail 671 and latching member 623 usable with the arm frame. The jaw can be a two tong die jaw.
The jaw head 13 and connected tapered jaw tail 671 have an axis 627 . The ends of the tapered jaw tail that extend from the jaw head come together toward the axis 627 .
The jaw head 13 and latching member 623 are shown extending away from the load surface 19 for latching the jaw tail into the pocket.
The second damper cavity 612 is shown surrounding the tail hole 608 .
FIG. 3C shows a side view of the tail hole 608 with the first damper cavity 610 and the second damper cavity 612 .
FIG. 4 depicts an exploded view of the jaw according to one or more embodiments.
The jaw 12 can have a plurality of tong die grooves, with each groove having a holding means.
Tong dies 26 a and 26 b can fit within each of the tong die grooves.
The first tong die 26 a can be held in the tong die groove using a first holding means, shown here as a ball 40 a and spring 41 a held by a fastener 42 a , forming a detent as the holding means.
The second tong die 26 b can be held in the tong die groove using a second holding means, shown here as a ball 40 b and spring 41 b held by a fastener 42 b , which can be identical to the first detent.
Each holding means can provide a holding compression to prevent the tong die from sliding out of the tong die groove.
A first rubber/elastomeric damper 615 can be disposed in the first damper cavity of the first side of the jaw tail. A second rubber/elastomeric damper 617 can be disposed in the second damper cavity on the second side of the jaw tail.
Two screws 45 a and 45 b can hold the second tong die 26 b in one of the tong die grooves.
Two screws 47 a and 47 b can hold the first tong die 26 a in the other tong die groove.
FIG. 5A depicts a side view of the tong die with teeth according to one or more embodiments. FIG. 5B depicts a cut view of the tong die of FIG. 5A .
A depression 198 can be in the first tong die 26 a for connecting with the ball of the holding means.
FIG. 6 shows the arm frame with the top plate connected to the bottom plate.
A pocket 600 for receiving the jaw tail 606 of the jaw 12 can be formed between the top plate 60 and the bottom plate 84 . A chain assembly 320 can connect opposite the face of the jaw 12 forming a secure engagement for gripping tubulars. The jaw is shown with the jaw head 13 .
The chain cylinder connection hole 112 a can engage a chain connecting pin to engage a first chain cylinder 114 .
The first chain cylinder 114 can have a cylinder body 117 and a rod 119 .
The first top chain connection hole 602 a and the first bottom chain connection hole 602 b can engage a chain connecting pin to secure the chain assembly 320 to the arm frame 56 .
The second top chain connection hole 607 a and the second bottom chain connection hole 607 b can engage a chain connecting pin to secure the chain assembly 320 to the first arm on an end opposite the first chain connecting pin.
A break-out/make-up cylinder 113 can be connected to the break-out/make-up cylinder connection hole 111 a with a pin through the arm frame 56 .
The jaw 12 can be fixedly secured between the top and bottom plates within the pocket 600 using the jaw retaining pin that engages the top fastening hole.
The break-out/make-up cylinder 113 can also engage a rigid body 700 using a break-out/make-up arm anchoring pin 703 .
The rigid body 700 can engage a second chain cylinder 714 using a chain connecting pin.
A second chain cylinder 714 can connect to a second jaw 712 that can engage a second chain assembly 720 for holding the first tubular.
FIG. 7 shows a chain assembly according to one or more embodiments.
The chain assembly 320 can have a plurality of chain links 326 a - 326 e , which can be connected in series.
A locking link 327 can be connected using a locking pin 331 to engage one of the chain links with the chain cylinder.
Each chain link can have a chain link face 328 a - 328 e and a chain link back 329 a - 329 e.
At least one tong die groove can be formed in each chain link face.
Each tong die groove can have groove edges for slidably receiving a tong die which opposes tong dies in tong die grooves on the jaw. Tong dies 26 a - 26 e are shown engaging the tong die grooves on the chain link faces of the chain links.
A plurality of handles 91 a - 91 c can be connected to the chain assembly.
In embodiments, one of the handles can be attached to a connecting link, a chain link, or a locking link.
Each handle can have an upper handle plate with an upper flat edge, a lower handle plate with a lower flat edge; an attachment plate integral with the upper flat edge and integral with the lower flat edge and extending between the upper handle plate and the lower handle plate; and a gripping post affixed between the upper handle plate and the lower handle plate.
In embodiments, each of the chain links can be connected to hinge pins 162 a - 162 d through the first top chain connection hole and the first bottom chain connection hole into the arm frame.
FIG. 8 depicts a detail of a chain link usable in the chain assembly according to one or more embodiments.
The chain link 326 a is shown with a groove 62 for containing the tong die 26 a on the chain link face 328 a of the chain link. A chain link radius 339 is also shown.
The chain link is depicted with the chain link back 329 a.
In embodiments, the face of the jaw can have three parallel tong die grooves and a tong die in one or more parallel tong die grooves.
The tong die grooves can have groove edges, which can incline towards a center line as the groove edges extend from the jaw body, such as at a 75 degree angle.
The face of the jaw can have a facial radius, which can be large enough to accommodate the tubular, such as a facial radius which can be from about 2 inches to about 60 inches.
The tong die can include one or more tooth beds. The tooth beds can support a plurality of teeth, which can extend from the tooth bed.
In embodiments, tong dies usable with the apparatus can have teeth. In other embodiments, tong dies without teeth can be used. The tong die usable in embodiments can be any tong die that is available for use in the make-up or break-out of tubulars.
The plurality of teeth can be used for gripping the tubular and can be of various shapes and spacing, such as pyramid shaped teeth spaced equidistant from one another with 8 rows and 16 columns of teeth total.
The tong die can include tooth bed edges. The tooth bed edges can have a slope, such as a slope of about 75 degrees. The slope of the tooth bed edges can provide a flush fit with the groove edges.
The present embodiments further relate to an apparatus usable with a method to break-out/make-up a pair of tubulars using a tong assembly for use in drilling a wellbore.
The method can include engaging the first tubular with the chain assembly connected to the rigid body.
The method can include pulling the chain assembly tight around the first tubular using the chain cylinder connected to the rigid body.
The method can include connecting the first tubular with the jaw secured to the rigid body.
The method can include connecting tong dies on the chain assembly to the first tubular.
In embodiments, the rigid body can be a fixed back up for the breaking-out and making-up of the first tubular with a second tubular.
The method can include engaging the second tubular with the second chain assembly connected to a break-out frame.
The method can include pulling the second chain assembly tight around the second tubular using the second chain cylinder to connect the second tubular with the second jaw secured to the rigid body and connect tong dies on the second chain assembly with the second tubular.
The method can include operating a break-out/make-up cylinder connected to the rigid body to perform a make-up operation by rotating the chain assembly in a first direction rotating the first tubular while holding the second tubular with the second chain assembly without movement of the second chain assembly creating a backup assembly that works as a vise in embodiments.
The break-out/make-up cylinder connected to the rigid body enables the two tubulars to connect together and form a tubing joint.
The break-out operation is performed by rotating the chain assembly in a second direction opposite the first direction.
The chain assembly can rotate the first tubular while holding the second tubular with the second chain assembly without movement of the second chain assembly creating a back-up assembly, enabling the two tubulars to separate and be broken-out.
In embodiments, the method can include using tubulars with an outer diameter from 1 inch to 36 inches.
In embodiments, the method can include pulling either of the chain assemblies tight around the tubular using pressures from 100 psi to 4000 psi.
In embodiments, the method can include rotating the chain assembly from 0 degrees to 90 degrees.
The method can include rotating the chain assembly from 0 degrees to 45 degrees for make-up of the tubulars and 0 degrees to 45 degrees for break-out of the tubulars.
The method can include using the chain assembly connected to the arm frame using a pair of chain assembly pins, one chain assembly pin connecting each end of the chain assembly, each chain assembly pin penetrating aligned chain connection holes in the top and bottom plate.
The method can include using a plurality of parallel tong die grooves with a tong die in each tong die groove on the face of each jaw and each chain assembly.
In embodiments, the method can include using the tapered jaw tail opposite the jaw head while maintaining at least 50 percent continuous contact between the outer surface and the load support walls between the top and bottom plates for load transfer from the jaw tail to the arm frame or the rigid body.
In embodiments, the method can include using each chain assembly to enable flexibility to connect around variable outer diameters of the tubulars.
In embodiments, each chain assembly can have the plurality of chain links connected in series and the locking link connecting one of the chain links to the chain cylinder.
In embodiments, the chain links can connect in series and connect around the tubular outer diameter.
The method can include using a plurality of handles. In embodiments, one of the handles can be attached to the chain link, or the locking link, providing gripping safety when installing the chain assembly around the tubular or removing the chain assembly from the tubular.
The method can include connecting each of the chain links in series to hinge pins through connection holes into the arm for quick connect and quick disconnect in the case of an emergency.
While these embodiments have been described with emphasis on the embodiments, it should be understood that within the scope of the appended claims, the embodiments might be practiced other than as specifically described herein.
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A tong assembly for use in make-up or break-out of a tubular. The tong assembly has a pair of chain assemblies connected to hydraulic chain cylinders, a first jaw connected to a first arm for supporting a first tubular, a second jaw connected to a break-out body between the break-out body and the second chain cylinder, and a make-out/break-out cylinder to push the chain cylinders in a make-up rotation or a break-out rotation allowing the assembly to provide changes of direction without changing tong assembly configuration or position.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
THE NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not Applicable
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
[0004] Not Applicable
BACKGROUND OF THE INVENTION
[0005] 1. Field of the Invention
[0006] The invention relates to compositions and method for clarifying oxidized headlight lenses and then sealing the clarified lenses.
[0007] 2. Description of the Related Art
[0008] Headlight “fading” is a condition that affects an automobile's ability to project light effectively. As opacity increases, light projection is reduced. Reduced light projection limits a driver's ability to see at night and reduces reaction time while driving in dark, twilight, or inclement weather. Therefore, headlight fading puts drivers, passengers, other motorists, and pedestrians at risk of accident.
[0009] Headlight fading is caused by chemical reactions occurring in the lens. Typically, headlight lenses are made from polycarbonate. Polycarbonate reacts with ultraviolet light and other environmental contaminants and oxidizes. The oxidation makes the normally clear lens cloudy and even yellow.
[0010] To retard the oxidation process, the factory may include a film over the polycarbonate that filters ultraviolet light. Over time the film's effectiveness deteriorates, and the UV reaction still occurs. In addition, the film can be damaged, scratched, or removed.
[0011] A first possibility is to replace the lens. However, because modern headlights are formed as integrated units including the lens, the entire headlight usually must be replaced. The cost of replacing a headlight is significant.
[0012] The simplest way to clarify a lens is to abrade the lens. Sanding and polishing will remove the oxidized outer layer. Unfortunately, abrading also removes any factory-installed coating. The result is the sanded lens will deteriorate quickly to a faded state because the protective coating has been removed.
[0013] Another alternative is using chemical solvents (i.e. non-aqueous organic solvents) to polish the lenses. First, the effectiveness of such solvents is questionable. In fact, the Applicant's research suggests that solvents may damage the lens. Second, for home use, the health and accident risks involving solvents are prohibitive. For commercial use, the risks, liability, and cleanup of organic solvents makes their use impracticable.
[0014] Methods for clarifying and sealing oxidized headlights have been proposed. However, the prior-art systems fail for at least one of the following reasons.
[0015] First, the system includes significant amounts of solvents. That is the primary solvent for the sealant is an organic solvent. Solvent-based systems dry quickly. However, they are volatile. In a commercial work shop, the solvents are dangerous and hazardous to the workers. The solvents are expensive to store, dispose, and clean. In home application, the solvents are dangerous to the users and pose a risk when stored. Their incorrect use can also damage the finish of a car.
[0016] Traditional aqueous sealants are not effective because they take too long to dry. Research has shown that for a sealant to be commercially useful, it must have a drying time of about five minutes. Longer drying times provide too high opportunity cost to the shop. For home users, long drying times risk contamination to the coating during drying.
[0017] Kropp et al. (US 2006/0201378) teaches a pretreatment formulation, resurfacing formulation, and a restoration formulation. The pretreatment formulation uses a volatile citrus terpene solvent. The resurfacing formulation includes a distillate, a polish, and water. The restoration formulation includes an aqueous polymer and water: in particular, metylmethacrylate and ethyl methacrylate, isocyanate polyurethane, N-methylpyrrolidone and triethylamine, or inhibited methylmethacrylate emulsion and or water miscible methylmethacrylate. Kropp et al. does not teach a system that is aqueous based and that can dry two coats of sealant in five minutes.
[0018] Ripley (US 2006/0263527) teaches cleaning but only to remove dirt, not to abrade oxidation. Ripley uses a caustic solution, which is hazardous. For a sealant, Ripley teaches one or more urethane coatings. Ripley does not specify what solvent is being used nor does it discuss a drying time.
[0019] Toth, III (US 2006/0217041) teaches three levels of sanding: 240X, 400X, 1000X. Toth does not teach a polymer sealant.
[0020] Cole et al. (U.S. Pat. No. 7,163,446) teaches to abrade a surface and then seal it with a film forming aqueous acrylic/urethane copolymer dispersion and UV protectant. The primary solvent is N-Methylpyrrolidone (NMP).
BRIEF SUMMARY OF THE INVENTION
[0021] It is accordingly an object of the invention to provide a method for clarifying and sealing a lens of a light, a composition for sealing a lens of a light, and a kit for clarifying and sealing a headlight, all of which overcome the above-mentioned disadvantages of the heretofore-known methods, compositions, and kits of this general type.
[0022] An object of the invention is to provide a method for clarifying an oxidized lens, in particular an oxidized headlight lens, and then sealing the clarified lens to minimize future oxidation.
[0023] A further object of the invention is to provide a composition that can be applied in two coats and dry in less than ten minutes, and more preferably less than five minutes, to a level where the sealant is no longer tacky and at risk of contamination if the automobile with the headlights is driven. This timing has been found to be a key time restraint for commercial garage applications. In these situations, the service provider will only use a product if the restoration process is relatively profitable for a given period of time. Otherwise, the repair-shop owner will use a bay for more profitable uses. In addition, the commercial user must be confident that the lens has sufficiently cured to allow the car owner to leave without risking the outcome of the job.
[0024] A further object of the invention is to provide a sealant with no or trace amounts of organic solvent. Chemical solvents are both fire and health risks. Compositions that include organic solvents are subject to environmental regulation. Commercial service centers tend to aggregate chemical wastes so even low amounts can aggregate to a significant amount. Trace amounts of organic solvent are amounts less than 2.5% weight. Trace amounts evaporate quickly enough that they do not accumulate to provide a health or safety risk, even in commercial uses.
[0025] In accordance with the objects of the invention, a method of sealing a surface of a lens to prevent oxidation of the lens is provided. The method for sealing can be performed after clarifying the lens or can be performed prophylactically to prevent oxidation of the lens. The method involves applying a coating that includes an aqueous urethane-modified acrylic sealer to the surface. The aqueous urethane-modified acrylic sealer includes an aqueous styrenic-acrylic emulsion. This combination has been found to produce a durable sealant that cures quickly enough to allow two coatings to be applied within five minutes.
[0026] In accordance with the objects of the invention, a second embodiment of a method of sealing a surface of a lens to prevent oxidation of the lens is provided. This method also calls for applying an aqueous urethane-modified acrylic sealer to the surface. The aqueous urethane-modified acrylic sealer includes an aqueous polyethylene emulsion. The inclusion of the aqueous polyethylene emulsion has also been found to produce a sealant that cures quickly enough to allow two coatings to be applied within five minutes.
[0027] In accordance with a further object of the invention, the method can provide for applying an aqueous urethane-modified acrylic sealer that includes both an aqueous styrenic-acrylic emulsion and an aqueous polyethylene emulsion.
[0028] In accordance with a further object of the invention, the surface of the lens is abraded before applying the aqueous urethane-modified acrylic sealer. Abrading the surface removes existing oxidation from the surface of the lens and prepares the surface to be sealed. Abrading can be performed by sanding and/or polishing. Typically, a series of finer abrasives are used to clarify an oxidized lens.
[0029] In accordance with a further object of the invention, the method calls for applying two coats of the sealant to the surface of the lens. The second coat helps to complete the seal and creates a smooth finished surface. The second coating is applied in the same direction as the first, preferably a continuous film from the top of the lens to the bottom.
[0030] By including an aqueous styrenic-acrylic emulsion and/or an aqueous polyethylene emulsion in the aqueous urethane-modified acrylic sealer, each coating dries quickly enough that two coating can be applied within five minutes and the sealant will have had enough time to at least partially cure to a degree in which normal driving of a vehicle will not compromise the seal.
[0031] In accordance with the objects of the invention, a composition is provided for sealing a surface of a lens. The compound includes an aqueous urethane-modified acrylic sealer. The aqueous urethane-modified acrylic sealer includes an aqueous styrenic-acrylic emulsion and/or an aqueous polyethylene emulsion.
[0032] In accordance with a further object of the invention, the sealant composition can include a polyurethane dispersion.
[0033] In accordance with a further object of the invention, the sealant includes n-methly-2-pyrolidone. N-methyl-2-pyrolidone accelerates the drying of the sealant after the sealant has been applied. The amount of N-methyl-2-pyrolidone is limited, preferably to less than three percent, to prevent the composition from being hazardous.
[0034] In accordance with a further object of the invention, a kit for clarifying and sealing a surface of an automobile headlight is provided. The kit includes all of the materials that for clarifying and sealing a lens of a headlight that are not normally available to a user. The kit includes coarse and fine sandpaper, polishing cream, a lint-free cloth, and a container of sealant. The coarse sandpaper has a grit no greater than 1000 for coarse abrading the surface of the automobile headlight. The fine sandpaper has a grit greater than 1000, and preferably as high as 3,000, for fine abrading the surface of the automobile headlight. The polishing cream polishes the surface of the automobile headlight after abrading. The polishing cream is stored in a single-use packet that can be torn open by hand. The amount of polish included in the package is an amount necessary to polish two large headlights. Accordingly, the amount of unused polish, which will require disposal, is minimized. A lint-free cloth is included for applying the polishing cream. Sealed packets that can be torn open by hand of the sealer are included. The packets hold a volume of the sealant that is sufficient to coat the surface of both of the headlight lenses twice. This amount provides enough to complete a single car but does not provide an excess of the sealant, which may be difficult to dispose. Household items like paper towels and a squirt bottle can be included or omitted to save packaging space and reduce cost.
[0035] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0000] Although the invention is illustrated and described herein as embodied in a method, a composition, and a kit for clarifying and sealing oxidized headlights, it is nevertheless not intended to be limited to the details shown, because 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.
[0036] 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 SEVERAL VIEWS OF THE DRAWING
[0037] FIG. 1 is a front side view of an automobile according to the Prior art.
[0038] FIG. 1A is a partial closeup view according to the prior art of a headlight shown in FIG. 1 .
[0039] FIG. 2 is a diagrammatic perspective view of kit according to the invention.
[0040] FIG. 3 is a diagrammatic view of the contents of the kit shown in FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
[0041] The following method is a preferred sequence of ordered steps for clarifying and sealing a headlight lens 102 of an automobile 100 .
[0042] A kit 1 for headlight restoration can be sold to consumers seeking to restore the headlights of their personally-owned cars. The kit 1 has a box 10 in which the contents of the kit are held together so that they can be sold as a unit.
[0043] The box 10 of the kit 1 holds a coarse sandpaper sheet 2 , a fine sandpaper sheet 3 , a polishing-cream packet 4 , a lint-free cloth 5 , and a sealant packet 6 . Because most households have paper towels 8 and a squirt bottles (which is preferably a trigger spayer) 7 , and because these items are bulky, they can be omitted from embodiments of the kit. Alternatively, embodiments of the kit include the squirt bottle 7 and paper towels 8 .
[0044] The first steps involve abrading the surface 103 of the lens 102 of the headlight 101 . The abrading step removes oxidation from the surface 103 of the lens 102 . Organic solvents are not necessary in the abrading steps.
[0045] In the first abrasion step, coarse sandpaper 2 is used. Coarse sandpaper 2 is defined as sandpaper with grit reaching one thousand 1000). The preferred grit for the first abrasion step is one thousand (1000) grit. The sandpaper is the type compatible with wet sanding. The surface 103 of the lens 102 is wetted with water, preferably, a squirt bottle 7 is used to wet the surface 103 of the lens 102 . Sanding is continued in either a circular motion or side-to-side motion until the oxidation is removed from the surface 103 of the lens 102 . A typical sanding time is three minutes to four minutes (3-4 min.) depending on the amount of oxidation and the size of the headlight 101 .
[0046] After the first abrading step, the lens 102 is preferably wiped clean with a paper towel 8 and then rewetted with the squirt bottle 7 . If necessary, the lens 102 may be rinsed with water to remove the “dust” from the sanding process.
[0047] Next, a second abrading step is performed using fine sandpaper 3 . Fine sandpaper 3 is defined as paper with grit greater than one thousand (>1000). A preferred grit for the second abrading step is two thousand five hundred (2500). The fine sandpaper 3 is preferably the type compatible with wet sanding. The surface 103 of the lens 102 is sanded in a circular motion or a side-to-side motion. A typical sanding time is one minute to two minutes (1-2 min.) depending on the amount of oxidation and the size of the headlight.
[0048] After the fine sanding step, the surface 103 of the lens 102 is wiped and dried with a paper towel 8 . If necessary, the lens may be rinsed with water from the squirt bottle 7 to remove the “dust” from the sanding process.
[0049] Next, the surface 103 of the lens 102 is polished. A polishing cream packet 4 is torn open and polishing cream is applied to the lens 102 with a lint-free airlay wiper 5 . The lint-free wiper 5 preferably has dimensions of 6.4 cm by 21.6 cm. For storage before use, the lint-free wiper is folded into a square comprised of four layers approximately 6.4 cm by 6.4 cm. Polishing is accomplished by rubbing vigorously in small circles with firm pressure. The surface 103 of the lens 102 is polished for one to two minutes (1-2 min.) depending on the size of the lens 102 .
[0050] After the abrading steps, the surface 103 of the lens 102 is thoroughly rinsed with water from the squirt bottle 7 to remove all residue from the abrading steps. Preferably, a paper towel 8 or equivalent absorptive towel is used. The lens 102 is completely dried with a paper towel 8 .
[0051] The next step involves the clarification and sealing of the surface of the lens. A sealer packet 6 is torn open. A first coat of an aqueous urethane-modified acrylic sealer (i.e. “the sealer”) is applied with an airlay lint-free cloth 5 . A cloth 5 having a size of 6.4 cm by 21.6 cm has been found to be useful for both application and for efficient storage before use. Before use, the cloth 5 is folded in a 6.4 cm by 6.4 cm square having four layers. The sealer is wiped across the surface 103 of the lens 102 in one direction from top to bottom with very light pressure until coverage is achieved. The first coat is allowed to dry, about two minutes (˜2 min.).
[0052] A second coat of the sealer is applied after the first coat has cured. The sealant for the second coat is preferably within the same sealant packet 6 as the first coat. The second coat is wiped across the lens 102 in the same direction as the first coating was applied: i.e. from top to bottom.
[0053] The first and second coat are held in the packet 6 . The packet 6 is torn open and poured onto a lint-free cloth 5 for application. Preferably, the sealant packet 6 contains only enough for two coats to a pair of the largest headlight lenses (i.e. pickup-up truck headlights).
[0054] A preferred embodiment of the sealant has the following formulation. Quantities are given as percentages of the total weight of the sealant. When available, the CAS number of an ingredient is listed. If not available, the ingredient's CAS Number is merely listed as “proprietary”.
[0000]
INGREDIENT
% TW
C.A.S. #
Polydimethylsiloxane
0.15-0.30%
proprietary
Flourosurfactant
0.12-0.28%
65545-80-4
Preservative
0.01-0.05%
proprietary
Styrenic acrylic emulsion
8-13%
proprietary
Styrenic acrylic emulsion
4.12-6.25%
proprietary
Polyetylene emulsion
0.25-1.1%
proprietary
Polyurethane dispersion
28-64.64%
proprietary
N-methyl-2-pyrolidone
0.1-2.35%
872-50-4
[0055] In one preferred embodiment, the invention encompasses a kit 1 . The kit 1 is a disposable, single use kit that includes all of the materials that are not available in any household (i.e. paper towels and a squirt bottle) and with enough supplies to clarify and seal both headlights of only one automobile. The kit includes a piece of coarse sandpaper 2 , a piece of fine sandpaper 3 , a lint-free cloth 5 , a packet of polish 4 with enough polish to polish up to two headlights of a large vehicle, a packet 6 of the sealant with enough sealant to provide two coats of sealant to both headlights of a car, and a lint-free cloth 5 for applying the sealant.
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A process, a composition, and a kit clarify and seal oxidized lens, especially headlight lenses. The process involves abrading the lens to remove oxidation and the sealing the lens with an aqueous urethane-modified acrylic sealer that includes an aqueous styrenic-acrylic emulsion or an aqueous polyethylene emulsion. The composition includes the sealant. The kit is an at-home device including the composition and utilizing the method.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims the benefit of priority to U.S. Provisional Patent Application No. 62/081,456 filed Nov. 18, 2014 and to U.S. Provisional Patent Application No. 62/081,554 filed Nov. 18, 2014, the contents of which are
FIELD OF THE INVENTION
[0002] The present invention relates to window shade or blind systems, and in particular relates to batten spacers adapted for use in roman shade systems and assemblies.
BACKGROUND
[0003] Roman window shade systems and assemblies include a shade and/or a backing fabric that is adapted to fold into a plurality of horizontal pleats as the shade is opened. The pleats are formed using rigid battens or sewn-in dowels or combinations of such elements. FIG. 1 shows a photograph of a side view of an example roman shade 10 in a fully opened position. In this opened position, the shade 10 , which typically disposed on the back of the assembly toward a window (not shown), forms a plurality of folds, e.g., 12 , 14 , 16 , and the battens, e.g., 22 , 24 , 26 to which they are coupled are collectively drawn into a backwards-J configuration. As the folds are compressed and forced backwards, they may come into contact with the window surface and accumulate condensation, and the contact with the window, trim and/or walls will push the stack of battens forward. For this reason, and also because the shade assembly can become unsightly and otherwise difficult to manipulate and release when the folds 12 , 14 , 16 become bunched in the manner shown, it would be useful to provide a means for a roman shade assembly to be opened fully without becoming distended in this disadvantageous way.
SUMMARY OF THE INVENTION
[0004] The present invention provides a shade assembly which comprises a shade fabric and a plurality of battens arranged vertically with respect to one another, each batten aligned horizontally along the fabric and forming a pleat therewith. A plurality of spacers are also provided which are coupled to and positioned adjacently to one of the plurality of battens in a direction perpendicular to a plane of the shade fabric. The plurality of spacers maintains the plurality of battens in a substantially vertical arrangement when the shade fabric is drawn into an open position.
[0005] According to one embodiment, the present invention also provides a batten spacer for a shade system including a plurality of battens, the batten spacer comprising an upper portion, a lower portion, and a planar element connecting the upper and lower portions. The upper and lower semicircular portions and the planar element define an interior space adapted to receive an annular element; a height from a bottom of the lower semicircular portion to a top of the upper semicircular portion is approximately the same as a height of one of the plurality of battens.
[0006] According to another embodiment, the present invention provides a batten spacer for a shade system including a plurality of battens, the batten spacer comprising a cylindrical annulus having a height that is approximately the same as a height of one of the plurality of battens, and a planar element extending tangentially to the cylindrical annulus, the planar element adapted to couple to cooperating receiving elements on the plurality of battens
[0007] Other features and advantages of the present invention will become apparent from the following description of the invention that refers to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The invention will now be described in greater detail in the following detailed description with reference to the drawings in which:
[0009] FIG. 1 is a photograph of a side view of an example roman shade assembly according to the prior art in a fully opened position.
[0010] FIG. 2 is a photograph of a side view of an example roman shade assembly with batten spacers according to the present invention.
[0011] FIG. 3 is a photograph of an end view of an example batten according to an embodiment of the present invention.
[0012] FIG. 4A is a perspective view illustration of a batten spacer according to one embodiment of the present invention.
[0013] FIG. 4B is another perspective view illustration of a batten spacer according to one embodiment of the present invention.
[0014] FIG. 4C is a top (or bottom) plan view illustration of a batten spacer according to one embodiment of the present invention.
[0015] FIG. 4D is a front plan view illustration of a batten spacer according to one embodiment of the present invention.
[0016] FIG. 4E is a side plan view illustration of a batten spacer according to one embodiment of the present invention.
[0017] FIG. 5 is a photograph of a side view of an example batten spacer according to one embodiment of the present invention, indicating an example scale of the spacer.
[0018] FIG. 6 is a photograph of an example annular element adapted to couple to a batten spacer according to an embodiment of the present invention.
[0019] FIG. 7 is a photograph of an example annular batten spacer according to another embodiment of the present invention.
[0020] FIG. 8 is a photograph of an embodiment of a batten spacer element according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] The foregoing summary, as well as the following detailed description of the embodiments of the present invention, is better understood when read in conjunction with the appended drawings. For the purposes of illustrating the invention, there is shown in the drawings an embodiment that is presently preferred, in which like numerals represent similar parts throughout the several views of the drawings, it being understood, however, that the invention is not limited to the specific methods and instrumentalities disclosed.
[0022] It will be understood that when an element is referred to as being “coupled” or “connected” to another element, it can be directly coupled or connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly coupled” or “directly connected” to another element, there are no intervening elements present.
[0023] FIG. 2 shows a photograph of a side an example shade assembly 200 according to an embodiment of the present invention, illustrating its contrast with the existing art shown in FIG. 1 . The shade assembly 200 includes a shade fabric 202 , coupled at a top end to a roller tube 204 and to a bottom panel 206 . Along the length of the fabric, a plurality of battens, e.g., 212 , 214 , 216 , are detachably coupled to the shade fabric 202 by pincer-like clamp elements that may clamp around dowel elements sewn in to the shade fabric 202 or simply clamp the shade fabric itself FIG. 3 is a photograph showing an end view of a batten 300 according to one particular embodiment of the present invention. As shown, the end of the batten 300 includes a first, larger pincer element 305 adapted to couple to the shade fabric and a second pincer element 310 which may form a track along the length of the batten to receive other coupling elements, as discussed further below. At the points where the plurality of battens, e.g., 212 , 214 , 216 couple to the shade fabric, pleats e.g. 222 , 224 , 226 are formed. The shade assembly 200 may be lifted or lowered by use of one or more lift cords e.g., 230 positioned along the horizontal length of the assembly. The lift cord 230 may be coupled, for example, to the bottom batten so that when the cord is pulled, the bottom batten is raised up to and pushes on the next lowest batten on so on, raising the entire assembly.
[0024] Positioned at intervals along the assembly 200 are stacks of batten spacers, 232 , 234 , 236 , each of composed of a plurality of individual spacers (e.g., a first stack 232 includes spacers 242 , 244 , 246 ). Each stack 232 , 234 , 236 includes one spacer for every batten e.g., 212 , 214 , 216 , and each spacer e.g., 242 , 244 , 246 is coupled to one of the respective battens. The spacers 242 , 244 , 246 are formed to have heights (in the vertical direction) approximately equivalent to the battens to which they couple. As shown in FIG. 2 , the stacks of 232 , 234 , 236 battens act as semi-rigid ‘spines’ preventing the assembly 200 from collapsing or distending in the manner shown in FIG. 1 . Rather, as indicated in FIG. 2 , when the shade assembly is opened, the plurality of battens remain in a substantially vertical arrangement instead of bending into a J-shape.
[0025] In some embodiments of the present invention, the spacers e.g., 242 , 244 , 246 do not couple directly to the plurality of battens, but rather, are each adapted to receive annular ring elements (not shown in FIG. 2 ), which in turn couple to the battens. Among the advantages of using annular elements, are that the lift cord can be made to run through the elements, preventing the lift cords from being manipulated in other directions aside from up and down. Shroud cords, e.g., 250 , which further prevent unintended extensions of the lift cord can also be attached to the annular elements, providing safety features.
[0026] FIGS. 4A-4E are engineering drawings of an embodiment of a batten spacer 400 according to an embodiment of the present invention. As shown in the perspective views of FIGS. 4A, 4B , batten spacer 400 includes an upper semicircular portion 402 , and a lower semicircular portion 404 , mutually connected at their curved portions via a planar element 406 . These elements bound an interior space 408 between the upper and lower portions adapted to receive and couple to an annular element (not shown). FIG. 4C shows a top or bottom plan view indicating a substantially semi-circular design of the top and bottom surfaces, and FIG. 4D shows a frontal plan view clearly indicating the upper 402 and lower 404 portions and the receiving space between 408 . FIG. 4E is a side plan view indicating a C-shaped cross-section of the exemplary batten spacer 400 . As clearly shown in the perspective view of FIG. 4B and also the side plan view of FIG. 4E , the bottom surface 410 of the upper semicircular potion 402 and the top surface 412 of the lower semicircular portion 404 include respective inclined protruding elements 422 , 424 that are adapted to provide a snap-fit connection with cooperating portions of an annular element. In addition, as the side view of FIG. 4C most clearly indicates, the upper and lower portions may contain hollow sections. It should be noted that the design of the batten spacer shown in FIGS. 4A-4E is by way of example and numerous modifications or alterations could be made to the batten spacer depicted and still remain within the scope of the present invention. For example, batten spacer as a whole can be formed in a different shape, and the upper and lower portions of the batten spacer in particular may be formed in another shape, for example, angled rather than semi-circular.
[0027] FIG. 5 is a photograph of a side view of an example batten spacer 500 according to the embodiment of the present invention shown in FIGS. 4A-E . The size of batten spacer of FIG. 5 is adapted for battens of a particular height of approximately 0.5 inches. While it is anticipated, given the heights of battens typically employed in roman shade assemblies, that the batten spacers between 0.06 and 1.00 inches in height may be used, these dimensions are not to be taken as limiting as the size of the batten spacers should be adapted to and match the height of the battens in any given shade assembly. The batten spacer may be formed from any suitably lightweight and substantially rigid material, such as a plastic.
[0028] FIG. 6 is a photograph showing a top view of an example annular element 600 adapted to couple to the batten spacers with the plurality of battens. The annular element includes a ring or annulus portion 605 adapted to be received in space 408 of the batten spacer. The annulus portion 605 may be secured in the receiving space 408 by snap-fit by virtue of the protruding elements 422 , 424 or otherwise securely coupled in the receiving space. In some embodiments, the annular portion 605 may have an inner diameter of approximately 0.3 to 0.4 inches and an outer diameter of 0.5 to 0.6 inches. Shade system cords, including the lift cords may extended through the central hollow region of the annular element. Shroud cords may run through the central region and/or may be directly attached to the annular element 600 . The annular element 600 also includes a planar element 610 that extends in a tangential direction on an outer edge of the annular portion 605 . Planar element 610 may be used to couple the annular element 600 to one of the plurality of battens of a shade assembly. According to one embodiment, mentioned above, planar element 610 may be inserted into a track formed within the extending pincer element 310 of a batten as shown in FIG. 3 . By this means, the annular element 600 , and the batten spacer, e.g. 500 , in which it is received, may be securely coupled to one of the battens of the shade assembly.
[0029] FIG. 7 shows a batten spacer according to another embodiment of the present invention, in which the functions of the spacer and annular element are combined in a single element. As shown, batten spacer 700 includes a annular portion 705 , which is cylindrical in the embodiment shown, having a height adapted to match the heights of the plurality of battens in the shade assembly, and a planar element 710 that extends in a tangential direction on an outer edge of the annular portion. The planar element may be inserted to into a track formed within the extending pincer element 310 of a batten as shown in FIG. 3 . By this means, the annular element 600 , and the batten spacer, e.g. 500 , in which it is received, may be securely coupled to one of the battens of the shade assembly.
[0030] FIG. 8 shows a batten spacer 800 according to yet another embodiment of the present invention. The batten spacer 800 has a height adapted to match the battens of the shade assembly and includes a hole 805 through which a cord (e.g., the shroud cord) may be threaded to secure the spacer from moving substantially in horizontal direction. However, other means may be used to secure the spacer 800 for undue horizontal movement such as staples, glue, a snap fit to the battens, etc. Batten spacers 800 may be positioned adjacent to annular elements 600 in a shade assembly and may be coupled directly to the annular elements (e.g., via a cord) or may not be directly coupled, depending on the implementation.
[0031] 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.
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The present invention provides a shade assembly which comprises a shade fabric and a plurality of battens arranged vertically with respect to one another, each batten aligned horizontally along the fabric and forming a pleat therewith. A plurality of spacers are also provided which are coupled to and positioned adjacently to one of the plurality of battens in a direction perpendicular to a plane of the shade fabric. The plurality of spacers maintains the plurality of battens in a substantially vertical arrangement when the shade fabric is drawn into an open position.
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