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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to compositions and methods for treating subterranean formations in order to make them more permeable. Such subterranean formations may, for example, be comprised of silicate minerals or carbonate minerals. Be the subterranean formation minerals as they may, this invention is especially concerned with matrix acidizing and/or fracture acidizing them in order to increase their permeability. Matrix acidizing is conducted below formation-fracturing pressures. Conversely, fracture acidizing is conducted at formation-fracturing pressures. In either case, any resulting increase in permeability of a formation can lead to increased production of a targeted material contained therein. For example, increased permeability in a hydrocarbon-bearing formation can lead to increased petroleum and/or natural gas production. Such increased permeability can also lead to increased production of non-hydrocarbon materials (e.g., carbon dioxide, sulphur, water, helium, etc.) from subterranean formations containing such materials.
Most matrix acidizing operations are aimed at increasing hydrocarbon production by dissolving subterranean formation clogging materials (especially those located near a borehole) and/or by invasion of existing pores and fractures in a subject formation. Any of these operations can be accomplished by pumping treatment fluids (e.g., acidic, aqueous solutions and/or gases) into a subject subterranean formation under pressures and flow rates such that the treatment fluid flows to and around any targeted subterranean formation clogging materials and/or into existing pore spaces and/or into existing fractures in the formation that may be clogged by granular materials. The acid components of such treatment fluids then chemically react with certain minerals contained in the formation clogging materials, pore spaces and clogged fractures. Such matrix acidizing operations also can create so-called “wormhole” systems in a matrix acidized formation. In effect, such wormhole systems are complex, three dimensional arrays of interconnected passageways.
Those skilled in the subterranean treatment arts will appreciate that there are at least four general types of matrix acidizing treatments: (1) wellbore cleanouts, (2) near-wellbore stimulation treatments, (3) intermediate matrix stimulation treatments and (4) extended matrix acidizing treatments. Each calls for use of different treatment techniques according to the distance between a wellbore and a targeted zone in a given subterranean mineral body. Those skilled in these arts also will appreciate that the acid treatment solutions used in each of these four treatment techniques tend to penetrate into subterranean formations for only relatively short distances before they are chemically spent. Indeed, this fact is part of the underlying basis for distinguishing between wellbore cleanouts, near-wellbore stimulation treatments, intermediate matrix stimulation treatments and extended matrix acidizing treatments.
It also should be understood that the selection of acids (and their concentrations) for each of these four treatment methods involves, among other things, further consideration of a given subterranean formation's: (1) mineral composition, (2) structure, (3) permeability, (4) porosity, and (5) physical strength. Other factors which then must be considered in the acid identity (concentration) selection process include, but are by no means limited to: (6) reservoir fluid properties, (7) temperatures, (8) pressures, and (9) any limitations on treatment fluid injection rates. Moreover, the identity and amounts of various additives, e.g., corrosion inhibitors, surfactants, and iron-control agents, friction reduction agents and so on, will vary with changes in the identity of a treatment acid (and its concentration). Cost considerations, ease of mixing, ecological concerns and safety considerations also are important factors in most matrix acidizing operations.
By way of distinction from matrix acidizing operations, fracture acidizing operations are carried out by pumping acidic fluids into subterranean formations at pressures and flow rates high enough to fracture that formation. There are also at least four primary fracture acidizing techniques: (1) fluid-loss control, (2) conductivity enhancement, (3) etched height control and (4) a variety of very specifically tailored fracture treatments. Regardless of the type of fracture acidizing technique being carried out, the acidic components of the high pressure fluids employed generally serve to etch fluid flow channels in newly fractured regions of that formation. The treatment solution volumes needed to carry out most fracturing operations are, however, generally much larger than those required for matrix acidizing operations. Hence, the expense of a fracture treatment solution may become a far greater factor relative to that of a matrix acidizing operation. Such cost of materials considerations also imply extensive design and/or lab work to determine, among other things, the mineral nature of the formation being fractured, identification of the most suitable acids, their optimal concentrations and/or the need for other chemical agents and/or particulate materials in the fracture treatment solution selected.
For example, some fracture treatments call for the use of particulate materials such as silica flour and 100-mesh sand particulates. That is to say that such particulate materials can be used to advantage in some fracture acidizing operations—but not in others—depending on the treatment acid selected. Other granular materials (e.g., graded rock salt, benzoic acid flakes, wax beads, wax buttons and/or oil-soluble resin materials) may have to be employed in other fracture acidizing operation depending on the identify of the acid selected (e.g., HF versus HCL). Selection of any of these particulate materials also implies further consideration of a host of subtle, complex and interrelated factors that very often compete with each other when they are used in the same subterranean treatment solution and/or fracture acidizing technique.
Prior Art HF and/or HCL Systems
Those skilled in the subterranean treatment arts also will appreciate that even though a wide variety of subterranean treatment solutions have been developed over the years, when all is said and done, hydrofluoric acid (HF), hydrochloric acid (HCL), as well as mixtures thereof, continue to be of the utmost importance. Hence, they will be used as a basis of comparison for the compounds, compositions and methods taught by the present patent disclosure. The pros and cons associated with the use of these two prior art acid types are numerous, wide ranging and sometimes rather subtle. For example, one might begin a comparison of the subterranean treatment uses of these acids by starting with HF and noting that it: (1) reacts with clays and silicates to remove formation damage caused by these materials, (2) is not normally used to treat limestone or dolomite formations or sandstone formations that also contain more than about 20% calcium carbonate because there is a strong possibility of HF forming calcium fluoride precipitates which can act as formation plugging materials, (3) is not normally used in sandstone formations without preceding its use with dilute HCL treatments, (4) is compatible with relatively more additives and matrix diverting agents (except rock salt) than HCL, (5) often requires a spacer between itself and a displacement fluid, and (6) requires shut-in times that are relatively more limited in order to reduce the possibility of formation damage through creation of formation clogging HF reaction product precipitates.
Next, it should be noted that certain subtle techniques concerning the use of HF as a subterranean treatment agent have been developed over the years. These subtleties often revolve around a desire to slowly form an active HF agent—preferably after the treatment solution has been injected into a subterranean formation—as opposed to directly injecting an HF-based treatment solution into that formation. For example, some HF treatment solutions have been created by first mixing ammonium bifluoride with water and then with HCL in order to slowly convert the ammonium bifluoride to hydrofluoric acid (HF)—after the solution has been pumped into a subterranean formation. Thus, the resulting relatively slow creation of the active HF agent enables the treatment solution to penetrate farther into a formation before it is chemically spent in reacting with those formation minerals that are dissolvable in HF. Hence, use of ammonium bifluoride is often preferred over the direct use of HF in many subterranean treatment operations.
Ammonium bifluoride starting materials also are often preferred over HF starting materials because ammonium bifluoride can be shipped to the field in the form of solid flakes that are readily soluble in water (that may be locally available). That is to say that the fact that ammonium bifluoride can be shipped in solid forms has important freight cost and ease of handling implications. It should also be noted, however, that ammonium bifluoride dust is extremely dangerous if it contacts the skin or is inhaled. The equipment and precautions against such skin contact or inhalation are, however, cumbersome for workers to employ, as well as expensive to buy and properly maintain.
Another alternative HF related subterranean treatment technology revolves around the finding that HF can be initially replaced with a fluoroboric acid precursor which also slowly hydrolizes to HF. Among other things, this chemical action causes certain clay platelets to fuse together and thereby cause them to more readily migrate toward a wellbore in a relatively more controlled manner. Still other alternative technologies employ organic acids (e.g., formic acid, acetic acid) in place of mineral acids such as HF because reactions of organic acids are generally easier to inhibit (especially at relatively high temperatures). Organic acids are also much more readily biodegradable. Such organic acids may, however, require use of greater acid quantities and/or concentrations as well as use of entirely different corrosion inhibitors, surfactants, precipitation prevention agents, stabilization agents, friction reduction agents and so forth relative to those used in conjunction with mineral acids such as HF and HCL.
By way of contrast with hydrofluoric acid treatments of silicate formations, carbonate formations (e.g., those containing large proportions of limestone and dolomite) are usually treated with hydrochloric acid. There are at least three generally recognized modes of hydrochloric acid attack upon carbonate formations. First, so-called “compact dissolution” occurs when hydrochloric acid expends itself on the face of such a formation. Second, so-called “uniform dissolution” takes place when hydrochloric acid reacts with carbonate minerals in ways such that fluid flow-penetration will be similar to the volumetric penetration of the acid. Third, highly conductive wormholes tend to be created in carbonate formations when hydrochloric acid invasion of such formations is uneven. Indeed, wormholing is the preferred mode of chemical attack upon carbonate formations. Hydrochloric acid treatments are also influenced by such factors as: surface reaction rates, acid diffusion rates and acid injection rates of the hydrochloric acid. It also should be noted that, generally speaking, HCL/carbonate reaction products are readily soluble in water. Hence, these reaction products are much less likely to precipitate out of solution relative to precipitation of HF/carbonate reaction products.
Next, it should be noted that regardless of whether the formation treatment is of the matrix acidizing variety or of the fracturing variety, most acid-based subterranean treatment solutions (such as those employing HF and/or HCL) usually include one or more agents in addition to their subterranean mineral dissolving acids. By way of examples only, such acid-based subterranean treatment solutions may, depending on the particular acid employed, contain different: (1) corrosion inhibitors, (2) surfactants, (3) precipitation prevention agents, (4) clay stabilization agents, (5) diverting agents, (6) friction reducing agents and the like (see for example U.S. Pat. No. 5,366,643 which teaches use of certain corrosion inhibitors in conjunction with HCL-based treatment solutions). These additional agents are generally well known. However, some of the more important points that might be made concerning certain reasons for their use, and/or representative examples of such additional agents, are listed below because they also can be employed as additional agents in the treatment solutions of the present patent disclosure.
Corrosion Inhibitors
Acids chemically react with steels to produce iron salts and hydrogen. Steel metallurgy, acid type (mineral, organic), acid strength and/or temperature are important factors in these reactions. The first widely used corrosion inhibitor was arsenic. Because of increased environmental concerns concerning the toxicity of arsenic, a variety of organic inhibitors have since been developed. Depending on the acid type being employed, many are based upon acetylenic alcohols (e.g., octynol and propargyl alcohol).
Iron Precipitation Prevention Agents
Steel dissolves to produce ferrous ions which, in the presence of dissolved oxygen, are often transformed into ferric ions. Ferric ions will normally precipitate from a treatment solution as its acid is used up and, hence, as the pH of the solution rises. Generally speaking, iron precipitation is addressed through use of chelation, sequestration and reduction agents depending on, among other things, the identity of the acid being employed in a given treatment solution.
Clay Stabilization Agents
Formation clays can react (by ion exchange or partial dissolution) with treatment solutions and thereby cause damage to a formation. To deal with this, various salts such as ammonium chloride and potassium chloride are added to different acid treatment solutions as clay stabilizers. However, it might also be noted here that potassium chloride is not normally employed when HF is present in the treatment solution because of the ability of its secondary precipitation product, potassium fluorosilicate, to cause formation plugging. It is also known that certain cationic materials (quaternary amines or polymers with similar reactive groups) can prevent clay swelling.
Surfactants
Surfactants e.g., foaming agents, water-wetting agents, oil-wetting agents, emulsifiers, demulsifiers and antisludge agents all have effects upon surface and/or interfacial tensions of subterranean treatment solutions. For example, water-wetting surfactants serve to lower the surface tension of HF aqueous treatment solutions and thereby increasing their ability to enter small pores. Demulsifiers serve to break up those viscous emulsions that tend to form between petroleum and certain acids. Ionogenic and nonionic agents are often used as surface active agents.
Diverting Agents
The most widely used materials used to divert treatment solutions are those particulates that are insoluble in the treatment solution. Such agents would include, but not be limited to, benzoic acid, naphthalene, gelsonite, wax beads and/or oil-soluble resins. Other systems have employed polymers that crosslink as the pH level of the treatment solution rises.
Friction Reducing Agents
Friction reducing agents are deposited on inside pipe wall surfaces in order to reduce the attractive forces between a given treatment solution and the piping system through which they will be pumped. In other words, the inside surfaces of the pipes being employed are “lubricated” so that pumping pressures—and, hence, pumping costs—can be lowered.
2. Discussion of the Background
The art/science of matrix acidizing traces its roots back over a hundred years, e.g., to a patent awarded to Herman Frasch (of Standard Oil) that taught the use of hydrochloric acid (HCL) to stimulate carbonate formations. That technology was, however, largely given up for many years because of the severe corrosion problems associated with the use of HCL in steel piping and wellhead equipment. It was, however, eventually revived (in the 1930's) after Dr. John Grebe (of Dow Chemical Company) discovered that arsenic can inhibit the corrosive effects of HCL on steel. This technology was, however, likewise, eventually given up owing to the extremely toxic nature of arsenic.
Earlier practitioners of the subterranean treatment arts also came to much more fully appreciate that very significant distinctions must be made between acid treatments of silicate formations—as compared to acid treatments of carbonate formations. It also came to be better appreciated that many minerals are bonded together by various kinds and amounts of cementing materials such as clays, feldspars, quartz, calcite, etc., and that many of these cementing materials are themselves silicates or carbonates that react differently with HF or HCL. It also came to be better appreciated that hydrofluoric acid reacts faster with some kinds of silicates relative to other kinds of silicates. For example, it is now generally understood that hydrofluoric acid tends to react relatively more quickly with authigenic clays such as smectite, kaolinite, illite and chlorite, especially at temperatures above about 150 degree F. It also came to be better recognized that, since clays are often a part of those cementitious materials that hold individual sandgrain components of sandstone materials together, dissolution of such clays tends to physically weaken certain matrices, especially sandstone matrices in the vicinity of wellbores.
Be all of the above matters as they may, it eventually came to be generally accepted that hydrochloric acid (HCL) does not react very well with most silicate materials, but that hydrofluoric acid (HF) does. This is the generally held modern view as well. For example, U.S. Pat. No. 5,529,125 (col. 1, lines 23–29) notes that treatment of siliceous formations with hydrochloric, acetic and formic acids “has little or no effect because they do not react appreciably with the silica and silicates which characterizes the sandstone formations.” Thus, many of the most widely used current methods of treating sandstone formations involve introducing hydrofluoric acid (or hydrofluoric acid precursors) into them, either via matrix acidizing treatments or via fracture acidizing operations.
Over the years, it also came to be recognized that many acid solutions tend to precipitate various complexes, and that these complexes (e.g., those of sodium and potassium salts of fluosilic acid) are highly insoluble, gelatinous materials that tend to plug formation pore spaces. It also came to be better understood that certain secondary reaction products will remain in solution if the pH of a treatment solution is kept low. By way of example only, U.S. Pat. No. 4,648,456 teaches acid treatment of hydrocarbon-containing formations through use of treatment solutions containing hydrofluoric acid and excess fluoride. In any case, both matrix acidizing operations and fracture acidizing operations are often highly concerned with using additional chemicals and/or field practices that serve to delay certain acid/mineral reactions and/or prevent precipitation of a wide variety of acid reaction products—given the type of mineral encountered.
Indeed, precipitation of various acid/mineral reaction products has proved to be an extremely persistent and vexing problem. In part, this follows from the multicomponent nature of the minerals that make up subterranean formations. Given these mineral complexities, prevention of precipitation of undesired HF acid/mineral reaction products has heretofore been tried (with varying degrees of success) through use of: (1) buffered systems, (2) other acids having fluorine atoms, e.g., fluoroboric acid, hydrofluorophosphoric acid and hydrofluorotitanic acid and (3) mixtures of esters and fluorides to generate HF in situ. By way of further examples of those methods employed to prevent precipitation of undesired reaction products, it might also be noted that phosphonate materials also have been used to prevent and/or inhibit certain silicate scales from forming during use of certain hydrochloric/hydrofluoric acid systems as well as during use of certain organic acid/hydrofluoric acid systems such as those that employ formic acid/hydrofluoric acid mixtures (see again U.S. Pat. No. 5,529,125).
Another widely used practice to prevent formation of HF based precipitates is to preflush a hydrocarbon-bearing formation with HCL in order to dissolve certain carbonate minerals that may be contained therein. That is to say that, if such carbonate minerals are not pre-dissolved, they may well react with an injected HF solution to produce calcium fluoride (CaF 2 ) reaction products that readily precipitate from a HF treatment solution and then clog the subject subterranean formation. Consequently, under many field practices, a HF/HCL solution is only injected into a formation after it has been pre-flushed with an HCL solution. After such treatments, many formations are also overflushed with weak HCL or ammonium chloride (NH 4 CL) solutions in order to force undesired reaction products away from a wellbore zone.
It was also eventually discovered that combining hydrofluoric acid (HF) with hydrochloric acid (HCL) in certain ratios serves to reduce the precipitation of certain reaction products that cause plugging. However, some guidelines previously used with respect to such HF/HCL mixtures have changed over the years. For example, optimum HCL/HF ratios were originally thought to be about 4:1 (e.g., 12% HCL, 3% HF solutions were, and still are, commonly employed) in virtually all cases. This ratio has, however, been modified, e.g., up to about 9:1 when certain minerals are present. These acid ratio modifications were based upon subsequent findings that reactions of certain clays with HF produce previously unrecognized secondary reaction products that tend to reprecipitate out of treatment solutions having HCL/HF ratios near 4:1, but do not precipitate out of solutions having ratios near 9:1. Be all this as it may, many, many treatment solutions containing hydrochloric acid/hydrofluoric acid mixtures are still widely used. They are often referred to as “mud acid(s).”
Thus, in summarizing the prior art, it might be said that both matrix acidizing operations and fracture acidizing operations each present a wide variety of problems associated with the identity of the acid(s) selected to carry out a given kind of treatment on a given type of subterranean mineral. Indeed, after more than 100 years of empirical observation of the effects of various acids, well research and development work and the like (e.g., with respect to core flow studies, geological and mineralogical studies, reaction kinetics, physicochemical modeling of propagating reaction fronts, solubility of reaction products testing, modern computer modeling, and the like), it can still be said that formulation of optimal matrix acidizing or optimal fracture acidizing solutions, for a targeted formation, is still highly problematic, complex and, hence, expensive to design and deploy. It might even be said that treating subterranean formations with a view toward increasing their permeability is still every bit as much an art as it is a science. But, it is also true that most newly developing technologies in the subterranean formation treatment arts, are, for the most part, still largely directed at: (1) retarding the acid/mineral reactions of a given formation material in order to achieve greater penetration of the formation before the subject acid is spent, (2) retarding corrosion of equipment, e.g., steel tubulars, wellheads, screens, etc., as well as retarding degradation of those polymeric seals found in such equipment, (3) preventing undesired chemical reactions (and especially those causing precipitation of reaction products that tend to plug such formations), (4) addressing environmental concerns, (5) addressing safety concerns and (6) lowering the costs of all such subterranean acidizing operations (not only by lowering material costs, but, even more importantly, by lowering the costs associated with the highly skilled and, hence, highly expensive labor needed to design and carry out such subterranean formation treatments).
Be all of the above problems, complexities and dilemmas of the prior art as they may, applicant has discovered that use of certain hereinafter described compositions in subterranean treatment operations can mitigate, otherwise improve upon and/or even virtually eliminate many of the above-noted problems. Indeed, it might even be fair to say that use of applicant's compositions goes beyond certain areas that were previously regarded as formidable technical barriers in the subterranean treatments arts. For example, the prior art does not disclose otherwise suitable subterranean treatment acids that are capable of attacking silicate minerals as well as carbonate minerals with comparable overall efficaciousness.
Applicant's compounds have this very, very desirable quality. Thus, the previously noted pros and cons surrounding the use of HF, HCL and/or mixtures thereof, in view of the type of formation mineral being treated (e.g., silicate versus carbonate minerals), are rendered far less important, or even moot, through use of applicant's subterranean treatment solutions. Nor does the prior art teach the use of chemical reactions that produce gases (e.g., oxygen) in quantities that serve to further power penetration of a treatment solution into a formation. In short, applicant has found that use of the hereinafter described family of compounds in subterranean treatment solutions addresses most of the above prior art concerns to very high degrees of satisfaction.
SUMMARY OF THE INVENTION
Applicant has found that use of certain compounds having the general formula XF.nH 2 O 2 , wherein X is K + , Na + , or NH 4 + and n is an integer from 1 to 3, in subterranean treatment solutions, produces a number of very important and wide ranging advantages relative to the use of those prior art compounds (e.g., HCL and/or HF compositions) heretofore used for such purposes. Some of the more important members of the above noted formula are peroxysolvate of potassium fluoride compounds i.e., KF.nH 2 O 2 compounds (hereinafter sometimes referred to as “PPF compounds” or “PPFs”), e.g., potassium fluoride hydroperoxide (KF.H 2 O 2 ), potassium fluoride dihydroperoxide (KF.2H 2 O 2 ) and potassium fluoride trihydroperoxide (KF.3H 2 O 2 ). Mixtures of two or more such compounds can be used to advantage as well, especially in “tailoring” subterranean formation treatments in tradeoffs between chemical reactivity versus formation penetration distances. For example, potassium fluoride hydroperoxide (KF.H 2 O 2 ) is more chemically reactive than potassium fluoride dihydroperoxide (KF.2H 2 O 2 ), but does not penetrate as far before it is chemically spent. This follows, in part, from the fact that reactions of potassium fluoride hydroperoxide (KF.H 2 O 2 ) with minerals produce less oxygen gas relative to those of potassium fluoride dihydroperoxide (KF.2H 2 O 2 ). Similarly, potassium fluoride dihydroperoxide (KF.2H 2 O 2 ) is more chemically reactive than potassium fluoride trihydroperoxide (KF.3H 2 O 2 ), but does not penetrate as far, for analogous, oxygen production related reasons. Thus, mixtures of 2 or more of these compounds can be employed to obtain optimal reactivity vs. penetration distance results.
Be that as it may, use of applicant's XF.nH 2 O 2 compounds serves to create more permeable subterranean formations relative to those created by the previously described prior art subterranean treatment acids. Such increased permeability can lead to enhanced production of a desired product from a given formation. For example, improved production of petroleum, natural gas, carbon dioxide, water, sulfur, helium and the like can be obtained from an appropriate subterranean formation that has been made more permeable by use of subterranean treatment solutions formulated and used according to the teachings of this patent disclosure.
One extremely important advantage of this invention follows from the fact that applicant's XF.nH 2 O 2 compounds can be used to dissolve both silicate mineral materials and carbonate mineral materials with similar effectiveness. Thus, for example, many hydrocarbon well stimulation design considerations, e.g., use of HCL vs. use of HF and/or mixtures thereof (in varying proportions), based upon the type of mineral(s) that comprise a given formation, and in view of the use of a wide variety of other agents, preflush treatments, identification of precipitation products, and the like, can be greatly minimized or, in many instances, virtually eliminated. Again, these facts and circumstances have great economic consequences, especially in terms of time savings for highly skilled (and, hence, highly paid) well design engineers and/or wellhead technicians. It might also be noted here that solutions of applicant's PPF compounds also can serve just as well as fracture acidizing fluids as matrix acidizing fluids. This attribute also serves to greatly reduce well design and/or well operation work efforts.
Moreover, the reaction times of applicant's XF.nH 2 O 2 compounds, and especially the peroxysolvate of potassium fluoride compounds, are relatively slow (e.g., compared to those of HCL and/or HF compounds) with respect to a very wide variety of formation minerals (e.g., silicates, carbonates, mixtures of silicates and carbonates as well as other entirely different subterranean formation minerals). As was previously discussed, “slowness” of reaction time can be a great virtue in treating certain subterranean formations. Moreover, this slowness is the case in treating all manner of different subterranean minerals (e.g., silicates, carbonates, mixtures thereof and so on). These relatively slower reaction times imply that applicant's treatment solutions can penetrate relatively farther into a formation before they are chemically spent or used up in reacting with whatever kinds of minerals they may encounter in a given subterranean formation. Applicant's compounds also can be encapsulated to further slow their reaction times. The herein described subterranean treatment solutions also can be employed as viscosity modifying agents when used in conjunction with suitable viscosity modifying agents.
The relatively slower reaction time attribute of these compounds also allows them to be used in matrix acidizing operations at relatively lower pumping pressures. Hence, their use in this manner is less likely to dislodge “fines” (fine particles) that otherwise might tend to plug a formation undergoing a matrix acidizing treatment. It also should be noted that most PPF/mineral reaction products are soluble (especially in water), and, hence, are not inclined toward precipitating out of applicant's PPF treatment solutions—and then plugging the formation being treated. Moreover, applicant has found that when certain PPF/mineral reaction products do precipitate from the subterranean treatment solutions of this patent disclosure, they tend to form granules (rather than gelatinous materials) that have void spaces between contiguous granules. The resulting void space volume between such granules implies greater permeability relative to more impervious gelatinous precipitation products.
Applicant's subterranean treatment operations are, however, also generally characterized by the fact that they often require somewhat longer “shut in” times relative to some prior art treatment (e.g., HF and/or HCL systems) solutions. Be that as it may, shut in times of from about 10 hours to about 50 hours will normally be required in applicant's subterranean treatment operations. Shut in times of from about 24 to about 36 hours are, however, the more likely time requirements for good overall technical results.
As previously noted, the ability of applicant's solutions to penetrate relatively farther into subterranean formations before being chemically used up follows at least in part from the fact that oxygen gas is one of the products of their reactions with a wide variety of minerals normally encountered in subterranean formations. That is to say that, once formed, this oxygen gas reaction product creates a gas pressure and, hence, a motive force that serves to propel, drive, urge, etc. any unused XF.nH 2 O 2 compound-containing solution “deeper” (i.e., laterally, upward, and/or downward) into a formation body, relative to a solution that is not so propelled by a gas product created by its own chemical reactions with a subterranean mineral. Thus, the “reach” or volume of a zone of permeability may be expanded through use of applicant's oxygen releasing—and, hence, at least partially self propelling—treatment solutions.
It also should be emphasized that applicant's subterranean treatment solutions will perform at very low PPF concentrations e.g., as low as about 0.5 weight percent of a liquid solution thereof. Such low concentrations imply important cost advantages over prior art treatment solutions having much higher active agent concentration requirements. Be that as it may, applicant's subterranean treatment solutions will perform over a very wide range of XF.nH 2 O 2 concentrations. Indeed, upper PPF concentration levels (e.g., above 50% by weight) in the PPF embodiments of applicant's subterranean treatment solutions are based as much upon economic considerations as upon technical ones. However, in balancing the efficacy of various treatment solutions versus their costs, applicant believes that treatment solutions containing from about 0.7 to about 20.0 weight percent XF.nH 2 O 2 compound(s) will give very good overall technical efficacy versus cost results. This is especially true in the case of PPF compounds.
When the PPF compositions of this patent disclosure are in their solid (e.g., granular or flake-like) forms, the PPF component of such compositions will normally constitute from about 2.5 to about 97.5 weight percent of the solid composition, with the remainder being a chemical stabilizer such as potassium hydrofluoride (KHF 2 ). Solid compositions comprised of about 50 weight percent PPF compound(s) and 50 weight percent of this chemical stabilizer will produce treatment solutions having wide ranging utilities. Normally, any additional components (corrosion inhibiting agents, surfactants, friction reducing agents and the like) used with applicant's PPF formulations will be added to the carrier fluids for these solid compositions in the field.
The PPF embodiments of applicant's XF.nH 2 O 2 compounds are also much more compatible with modern environmental concerns (especially when compared to HF and/or HCL systems). That is to say that the PPF compounds of this patent disclosure are not toxic; moreover, they are readily biodegradable. It also might be noted in passing that, in the absence of any pH influencing agents, the pH of applicant's PPF treatment solutions will be about 7.0. This fact has useful implications in its own right. At the very least, it implies that these solutions are far less hazardous relative to those HF, HCL acids heretofore employed as subterranean treatment agents. Hence, they can be more safely mixed above ground, injected into the ground and then left down-hole to be biodegraded rather than recovered (at great expense) pursuant to ecological concerns and/or legal mandates associated with recovering more dangerous treatment solutions. Another great advantage follows from the fact that applicant's PPFs are not corrosive to steel (nor to iron, copper or brass). Indeed, they form a protective film over steel that serves to protect it from other corrosive fluids that may be used in the overall operation of a given well. Moreover, and unlike most prior art treatment acids, applicant's PPF compounds do not chemically attack sealing rings and other devices made of polymeric materials (e.g., rubber, plastics and the like) commonly employed in oil field equipment.
Yet another advantage of applicant's PPFs resides in the fact that they can be shipped to the field as solids (e.g., in granular or flake-like forms). In other cases, they can be shipped to the field as highly concentrated liquids. Wellhead workers will, however, normally prefer to have these PPFs shipped in their solid forms in conveniently sized bags, boxes, plastic containers and the like—and then mix them with their carrier fluids, additional agents, etc., in the field. Aside from the ammonium bifluoride compounds previously noted, this ability to be shipped in solid forms is not true of most other subterranean formation treatment agents. For example, hydrofluoric acid and hydrochloric acid are always shipped in liquid forms—at relatively much greater expense—owing to the fact that these acids are only chemically stable as liquids. These HF/HCL liquid acids also are highly toxic and otherwise dangerous to ship, store and deploy. By way of contrast, applicant's PPF compounds are much more safe and convenient to ship, store, handle and deploy.
The solid forms of applicant's PPFs also can be given relatively long shelf lives (e.g., up to about 2 years) when properly stabilized—e.g., by use of a KHF 2 stabilizer. These PPFs are also easily mixed in the field because they do not tend to lump when placed in contact with their carrier fluid (e.g., water); nor do they tend to settle (or phase separate) in well site holding tanks. They also can be mixed down hole as well as above ground. Moreover, they are chemically stable over a wide range of operating temperatures (e.g., from about minus 7° C. to about 150° C.—under appropriate pressure conditions). It might also be noted in passing that, relative to HF/HCL treatment solutions, the compounds of the present patent disclosure are much less inclined to swell certain clays (e.g., bentonite), especially when they are placed in carrier fluids other than water (e.g., petroleum based fluids, alcohols and crude oil). They also serve as bactericides against a wide variety of formation clogging microbial organisms.
Applicant's PPF solutions are also especially effective in stimulating production of heavier petroleums that have resisted the stimulative action of many prior art treatment solutions. Furthermore, applicant's XF.nH 2 O 2 treatments can be used in place of conventional present day treatments (e.g., HCL and/or HF treatments), or they can be used after such conventional treatments have reached their technical and/or economic limits. By way of illustration of this point, applicant's PPF solutions produced greater permeability in petroleum-containing formations from which no further economic production could be obtained through use of commonly employed prior art treatment solutions. For example, a treatment solution formulated according to the teachings of this patent disclosure (containing KF.H 2 O 2 and a KHF 2 stabilization agent) was injected into a well whose petroleum production had fallen to about 0.68 tonnes/day using a commonly employed treatment solution. Thereafter, treatment of this well with one of applicant's PPF treatment solutions raised the well's production to 56.0 tonnes/day. Needless to say, such greater production, especially after prior art methods have failed, has very significant economic implications.
Applicant's XF.nH 2 O 2 compounds can be employed with various carrier fluids (e.g., water, petroleum-based fluids such as diesel fuel, kerosene and or distillates, alcohols and crude oil). These carrier fluids can further comprise propellant gases such as steam, carbon dioxide, nitrogen, air, various certain hydrocarbon gases, etc. Indeed, the carrier fluids for applicant's PPF solutions can themselves, in some instances, be gases/vapors (e.g., steam, nitrogen, carbon dioxide and a wide variety of hydrocarbon-based gases). Water is, however, the generally preferred carrier fluid for both technical and economic reasons. Again, water is an especially useful carrier fluid because many XF.nH 2 O 2 /mineral reaction products are soluble in water. Moreover, the quality of the water that may be successfully employed in applicant's treatment solutions can vary considerably. For example, sweet water, mineralized water, stratal water and the like (as well as mixtures thereof) can be effectively employed. The pH of a water carrier for applicant's subterranean treatment solutions also can vary over extremely wide ranges (e.g., from a pH levels as low as about 0.5 up to as high as about 14.0). Hence, a wide variety of commonly available (and hence relatively inexpensive) acidic materials (e.g., hydrochloric acid, acetic acid and sulfuric acid) or basic materials (e.g., potassium hydroxide, sodium hydroxide and calcium hydroxide) can be used to adjust the pH of applicant's treatment solutions—when they need to be so adjusted. Yet another valuable attribute of applicant's solutions is that they do not react to any great extent with certain metal ions (e.g., iron ions) that may be dissolved in ground waters that the treatment solutions of this patent disclosure may encounter.
Next, it should again be specifically noted that potassium hydrofluoride (KHF 2 ) can be employed to great advantage in conjunction with many of the XF.nH 2 O 2 compounds of this patent disclosure for reasons other than pH adjustment. It is, for example, especially useful as a PPF stabilization agent, and especially with respect to potassium fluoride hydroperoxide (KF.H 2 O 2 ). Applicant has, for example, found that potassium hydrofluoride (KHF 2 ) is particularly effective in stabilizing PPFs, e.g., to an extent such that certain solid PPFs (e.g., KF.H 2 O 2 ) can have their shelf lives extended from about two weeks to about two years through use of KHF 2 as a PPF stabilizer. Again, this increased shelf life attribute has great practical and economic implications. This potassium hydrofluoride (KHF 2 ) stabilizer can be added to the PPF compounds during the PPF manufacturing process, or it can be added to a PPF solution in the field.
This KHF 2 component of a subterranean treatment solution may also aid in releasing oxygen gas from PPFs as they undergo chemical reactions with subterranean minerals. Again, this oxygen gas release produces a motive force (e.g., a motive force in its own right, i.e., a motive force beyond those supplied by mechanical pumps) for driving any remaining treatment solution farther into a given formation material; and this is true whether the formation is comprised of silica materials, carbonate materials or other minerals. It is also true whether matrix acidizing or fracturing acidizing operations are being carried out. The KHF 2 also can serve, in part, to retard the rate at which applicant's PPFs react with those formation minerals they encounter. Again, any such chemical reaction “slowdowns” generally serve to enhance a treatment solution's penetration into a subterranean formation. This source of such chemical slowdowns can, for example, be used in conjunction with the fact that applicant's potassium fluoride trihydroperoxide (KF.3H 2 O 2 ) compositions tend to penetrate farther than the potassium fluoride dihydroperoxide (KF.2H 2 O 2 ) compositions because KF.3H 2 O 2 produces more motive force-supplying oxygen gas. Similarly, potassium fluoride dihydroperoxide (KF.2H 2 O 2 ) compositions tend to penetrate farther than potassium fluoride hydroperoxide (KF.H 2 O 2 ) compositions for the same analogous, oxygen gas production reasons. In some cases, the KHF 2 also serves to improve the complexing capacity of PPF-based subterranean treatment solutions.
This KHF 2 stabilization agent also can be used in subterranean treatment solutions in relatively low concentrations. In general, if used at all, a KHF 2 stabilization agent will normally constitute at least about 0.5% by weight of a resulting PPF/KHF 2 /water treatment solution. Treatment solutions having from about 0.7 to about 50.0 weight percent of KHF 2 can more generally be employed. Here again, however, for economic reasons, as well as technical ones, treatment solutions having from about 0.7 to about 20.0 weight percent of a KHF 2 stabilizer will normally be employed. Thus, a representative subterranean treatment solution containing both a PPF compound and a KHF 2 stabilizer might comprise from about 0.7 to about 20.0 weight percent PPF and from about 0.7 to about 20.0 weight percent KHF 2 . Thus, under the teachings of this invention, a more specific representative subterranean treatment solution might comprise:
KF · H 2 O 2
0.7–20.0 weight percent
KHF 2
0.7–20.0 weight percent
water
Remainder
Moreover, the KHF 2 stabilization agents can be used with a variety of carrier fluids such as water, alcohols, ketones, petroleum-based fluids (e.g., diesel fuel, kerosene, distillates and crude oil) and so on. And here again, in cases where KHF 2 is used, the carrier fluids can even be vapors/gases (e.g., steam, air, nitrogen, carbon dioxide, natural gas and/or other hydrocarbon-based gases) as well as liquids. Furthermore, it should also be noted that applicant's XF.nH 2 O 2 treatment solutions are just as effective over comparably wide ranges of operating pressures and operating temperatures (e.g., from about minus 7° C. to about 150° C.) when they are used in conjunction with KHF 2 , as well as when they are used alone. The fact that applicant's overall PPF/KHF 2 compositions are still active at 100° C. (and greater—due to superheating allowed by greater pressures) implies that a gas or vapor (such as steam or hydrocarbon vapors) can act as a carrier fluid for such compositions.
As in the case of the prior art treatment solutions, applicant's subterranean treatment solutions may further comprise a wide variety of other well known agents (e.g., those corrosion inhibitors, iron precipitation prevention agents, clay stabilization agents, surfactants, friction reducing agents and/or diverting agents previously noted in this patent disclosure, or otherwise known to those skilled in these arts). Generally speaking, each such additional agent may comprise from about 0.01 to about 5.0 weight percent of an overall treatment solution. Such additional agents, in total, will not, however, normally comprise more than about 40 weight percent of applicant's overall treatment solutions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts one of the comparative advantages of a representative PPF-based treatment solution relative to a prior art treatment solution in terms of their relative abilities to dissolve a given mineral system over time.
DETAILED DESCRIPTION OF THE INVENTION
Applicant conducted a number of experiments to establish the general and relative abilities of these XF.nH 2 O 2 compounds (and especially the PPF embodiments of the XF.nH 2 O 2 compounds) to chemically and/or physically dissolve various minerals at various acid concentrations, temperatures (in and out of the presence of additional agents) and so on. By way of example only, FIG. 1 graphs time on the X axis versus the chemical and/or physical dissolution rate of a representative subterranean mineral material on the Y axis under the respective dissolution actions of the two subterranean treatment solutions being compared. A first curve, labeled TK-2, is depicted by a line having a series of rectangles at certain points on that curve. It represents the chemical/physical dissolution action of a commonly employed treatment solution, known as TK-2, upon the subject mineral. A second curve, labeled PPF, is depicted by a line having a series of diamonds at certain points on that curve. It represents the chemical/physical dissolution of the same mineral by the action of a representative PPF-based solution.
More specifically, the PPF solution used to create the PPF curve of FIG. 1 was comprised of 20 weight percent KF.H 2 O 2 , and 0.3 weight percent KHF 2 and water. The TK-2 solution was comprised of ammonium chloride, ammonium fluoride, a surface active agent and certain chemicals that encourage production of HCL and HF by hydrolysis of the ammonium chloride and the ammonium fluoride ingredients. This commercially available TK-2 solution was mixed with five parts of sweet water to create a resulting treatment solution. The mineral material used in each test was the same type (and the same physical form) of siliceous material (i.e., quartz tubes). The relative ability of each solution (PPF versus TK-2) to dissolve the quartz material was confirmed by weighing the respective quartz tube materials at various points in time (0.5 hrs., 1 hr., 2.4 hrs., 3.2 hrs., 4.7 hrs. as generally suggested by the data points in FIG. 1 ). In effect, the weight differences of the quartz tubes over time measured the relative abilities of the two solutions (PPF versus TK-2) to dissolve the subject quartz material.
FIG. 1 also shows that the curve labeled TK-2 reaches its peak rate of reaction (i.e., about 0.8 gr/(m 2 ·hr)) in about 0.5 hours. Thereafter, its reaction rate falls off relatively quickly. For example, after about one hour's time its reaction rate has fallen to about 0.34 gr/(m 2 ·hr). After that, the TK-2 solution's reaction rate decays more slowly. For example, after about 3.75 hours the TK-2 reaction rate has fallen to about 0.2 gr/(m 2 ·hr). By way of contrast, the curve labeled PPF reaches its peak rate of reaction (i.e., about 0.62 gr/(m 2 ·hr)) in about 0.9 hours. Thereafter, it decays much more slowly relative to the decay of the TK-2 curve. For example, the reaction rate of the PPF solution, after about 2.4 hours, is about 0.45 gr/(m 2 ·hr). By way of further comparison, the reaction rate of the TK-2 curve is about only 0.25 gr/(m 2 ·hr) after the same 2.4 hours. It also should be noted that these two curves (TK-2 and PPF) have a first point of intersection F at about 0.6 hours when they both have a reaction rate of about 0.57 gr/(m 2 ·hr).
The fact that the TK-2 curve reaches its peak in about 0.5 hours while the PPF curve takes about 0.9 hours to reach its peak has great practical significance. Suppose, for example, that both the TK-2 solution and the PPF solution, under comparable pumping pressures, penetrate a given formation material to an equal distance of one half meter in the first one half hour of the treatment. Further suppose that both the TK-2 solution and the PPF solution (again under comparable pumping pressures) penetrate the formation to an equal distance of one meter in the first full hour of the treatment. Similarly, suppose that the TK-2 solution and the PPF solution (once again under comparable pumping pressures) thereafter each penetrate the formation an additional one half meter for each additional half hour of treatment time. Those skilled in this art will appreciate that this linear, one half meter per one half hour penetration, rate is a highly “idealized” assumption. It is however applied to both the TK-2 and the PPF solutions. These idealized assumptions also neglect the motive power supplied to the PPF solution by its oxygen gas product. Nonetheless, these assumptions are useful in making the general points applicant wishes to make. That is to say that, under such uniform penetration distance versus time assumptions, FIG. 1 shows that the TK-2 solution has penetrated about one half meter into the formation as it reaches its maximum rate of reaction (0.8 gr/(m 2 ·hr)). However, by the time the TK-2 solution has penetrated the formation to a distance of about 1 meter (i.e., in one hour), its rate of reaction has fallen to about 0.34 gr/(m 2 ·hr). Thereafter, the TK-2 curve decays more slowly. For example, after about 4.7 hours, the TK-2 solution's rate of reaction is about 0.18 gr/(m 2 ·hr). This is also a second point S where the TK-2 curve and the PPF curve again intersect.
Comparing the TK-2 curve with the PPF curve one also notes that at one half hour's time (when the PPF solution has penetrated the formation to a distance of one half meter), the PPF solution's reaction rate has not yet reached its maximum. Stated another way, the PPF curve reaches its maximum (0.62 gr/(m 2 ·hr)) after about 0.9 hours time and after the PPF solution has penetrated the formation to a distance of about one meter. Again, by way of comparison, the TK-2 solution reaches its peak reaction rate when it has penetrated the formation to a distance of only about one half meter. In other words, when the PPF curve has reacted its peak (0.62 gr/(m 2 ·hr)) the TK-2 curve has fallen to about 0.34 gr/(m 2 ·hr) (which is less than half of its one half hour peak value of about 0.8 gr/(m 2 ·hr)). Thereafter, the PPF reaction rate remains above the TK-2 reaction rate until the two curves finally cross again at point S, i.e., at about 0.18 gr/(m 2 ·hr)after about 4.7 hours. Hence, FIG. 1 shows that the PPF solution remains more reactive (relative to the TK-2 solution) after about 0.6 hour's time and remains more reactive up to about 4.7 hour's time. Stated another way, the area under the PPF curve and above the TK-2 curve between their first point of intersection F (0.6 hours and 0.57 gr/(m 2 ·hr)) and their second point of intersection S (4.7 hours and 0.18 gr/(m 2 ·hr)) represents an area of improved ability of the PPF solution (relative to the TK-2 solution) to act as a mineral formation permeability enhancing agent.
Table 1 shows the relative abilities of certain representative subterranean treatment solutions of this patent disclosure to dissolve a representative silica mineral (i.e., quartz in the form of quartz tubes). These solutions employed a representative PPF (KF.H 2 O 2 ) in the varying proportions indicated (e.g., 10.0, 0.96 and 20 weight percent of the overall solution). A potassium hydrofluoride (KHF 2 ) stabilization agent was also employed in the varying proportions indicated (e.g., 10.0, 20.0 and 1.0 weight percent). All of these solutions also contained a surfactant and a corrosion inhibitor in the respective concentrations indicated (i.e., 0.8 weight percent and 0.05 weight percent). These tests were conducted at two representative temperatures (i.e., 20° C. and 70° C.). Contact times of 0.5, 1.0 and 5 hours were employed with respect to each composition. Table 1 (see line 4) also shows the relative ability of a prior art HCL-based, subterranean treatment solution to dissolve the subject quartz mineral. Since quartz is a silica mineral, the HCL-based, prior art solution (patented in Russia) was generally unable to chemically attack said mineral. This fact is reflected by the notation “Did not react.” Generally speaking, Table 1 also indicates that as the contact time increases, the rate of reaction decreases while the quantity of quartz dissolved generally continues to increase. In comparing the dissolution effects of the 10, 0.96 and 20 weight percent KF.H 2 O 2 solutions, it also will be generally noted that the higher KF.H 2 O 2 concentrations (i.e., 10 and 20 percent) respectively dissolve more of the subject quartz material than the 0.96 KF.H 2 O 2 solution.
Table 2 is similar to Table 1. The main distinctions are that the material being dissolved is a carbonate, the temperature is held constant (at 20° C.) and the contact times are measured in minutes, i.e., at 10, 30, 90 and 300 minutes. Table 2 indicates (see line 4) that the relative ability of a prior art (patented in Russia), HCL-based subterranean treatment solution to dissolve the subject carbonate material. Since the subject material is a carbonate, the HCL-based, prior art solution was able to chemically attack it. Thus, Table 2 demonstrates that these KF.H 2 O 2 solutions were able to chemically attack a carbonate material as well as a quartz (silica) material. However, Table 2 also shows that the 10.0 and 0.96 percent KF.H 2 O 2 solutions dissolved more of the subject carbonate material, while the results of the 20 percent KF.H 2 O 2 solution were comparatively more modest. Nonetheless, all of the KF.H 2 O 2 solutions generally dissolved more of the subject carbonate material than the HCL-based, prior art solution—especially in the earlier (e.g., 10 and 30 minute) stages in these experiments.
Table 3 shows a variation of tests that produced the results given in Table 1. The main difference between Table 1 and Table 3 is that Table 1 is concerned with the relative abilities of certain representative subterranean treatment solutions to dissolve quartz, while Table 3 is concerned with the relative abilities of the same representative subterranean treatment solutions to dissolve a representative clay (a silicate material). Table 3, like Table 1, also shows the relative ability of a prior art (patented in Russia) HCL-based, subterranean treatment solution to dissolve the subject clay material. Here again, since clay is a silicate material, the HCL-based, prior art solution was unable to chemically attack said material. This fact is reflected by the notation “Did not react.” Generally speaking, Table 3 also indicates that as the contact time increases, the quantity of clay material dissolved generally increases. The negative numbers in the “Quantity of sample Dissolved, %” column of Table 3 follows from the fact that, in these cases, the subject clay material came out solution and formed particulate materials. Nonetheless, the structure of the subject clay material changed—even though solid particulate materials came out of solution—in a manner that increased the relative permeability of that subject clay material.
Table 4 shows the relative abilities of the subterranean treatment compositions of Table 1 to increase the permeability of a clay core sample. This clay core sample was taken from a well in the Koshil Oil Field in western Siberia. This permeability enhancement was established by pumping the various PPF treatment solutions given in Table 4 through respective core samples whose clay content was 10% by weight. The other factors associated with these tests are given at the top of Table 4. Here again, the results of these tests are compared to those produced by a prior art (patented in Russia) HCL-based solution. Generally speaking, Table 4 shows that each of the three KF.H 2 O 2 compositions served to increase the permeability of the core clay material relative to the prior art HCL-based subterranean treatment solution.
TABLE 1
Composition of System
Alkyl
Phosphate
Surface
Active
Quartz Dissolving Reaction
Agent
Corrosion
Contact
Rate of
Quantity
Composition
KF · H 2 O 2
Water
Surfactant,
Inhibitor
Temp.
Time
Reaction,
of sample
Example
Type
Mass %
KHF 2
pH
Mass %
Composition %
° C.
Hrs
g/m 2 · hr
Dissolved, %
1
PPF
10.0
10.0
2
0.8
0.05
20
0.5
0.8
0.034
1
0.4
0.034
5
0.11
0.046
70
0.5
0.91
0.038
1
0.82
0.067
5
0.15
0.059
2
PPF
0.96
20.0
6.5
0.8
0.05
20
0.5
0.78
0.035
1
0.33
0.028
5
0.16
0.066
70
0.5
0.18
0.008
1
0.96
0.078
5
0.8
0.34
3
PPF
20
1
10
0.8
0.05
20
0.5
0.53
0.023
1
0.62
0.052
5
0.14
0.058
70
0.5
1.22
0.05
1
0.44
0.038
5
0.32
0.13
4
Prior Art
Did not react
Solution 1
1 A prior art, HCL-based, solution was used as a basis for comparison of the solutions of this patent disclosure. It did not react.
TABLE 2
Composition of System
Alkyl
Phosphate
Surface
Carbonate Dissolving Reaction
Active
Quantity
Agent
Corrosion
Contact
Rate of
of
Composition
KF · H 2 O 2
Water
Surfactant,
Inhibitor
Temp.
Time,
Reaction,
sample
Example
Type
Mass %
KHF 2
pH
Mass %
Comp %
° C.
Min
g/m 2 · hr
Dissolved, %
1
PPF
10.0
10.0
2
0.8
0.05
20
10
117.8
25.45
30
56.22
66.58
90
12.03
31.93
300
5.01
5.11
2
PPF
0.96
20.0
6.5
0.8
0.05
20
10
332.2
47.89
30
57.34
23.23
90
4.09
4.99
300
0.07
0.29
3
PPF
20
1
10
0.8
0.05
20
10
83.25
11.1
30
58.77
25.8
90
21.29
28.8
300
0.67
2.87
4
Prior Art
30
10
107.8
12.8
Solution 1
30
65.23
23.61
90
10.43
15.45
300
0.3
1.09
1 A prior art, HCL-based, solution was used as a basis for comparison of the solutions of this patent disclosure. The last line (4 th ) in this Table 2 is for that prior art, HCL-based, solution.
TABLE 3
Composition of System
Phosphate
Clay Dissolving
Surface
Reaction
Active
Clay
KF ·
Agent,
Corrosion
Dissolving
Composition
H 2 O 2 ,
Mass %
Inhibitor
Temp.
Contact
Rate of
Example
Type
Mass %
KHF 2
Water pH
Surfactant
Comp %
° C.
Time hr
Reaction, %
1
PPF
10.0
10.0
2
0.8
0.05
70
0.5
−8.9
1
3.94
5
0.84
2
PPF
0.96
20.0
6.5
0.8
0.05
70
0.5
4.12
1
2.01
5
8.34
3
PPF
20
1
10
0.8
0.05
70
0.5
−26
1
−2.28
5
−1.27
4
Prior Art
70
Did not react
Solution 1
1 A prior art, HCL-based, solution was used as a basis for comparison of the solutions of this patent disclosure. It did not react.
TABLE 4
Quantity of Clay in the Cores: 10 Mass %, Porosity - 12.26%, Pore Value - 3.85 CM 3 ,
Cubic CM Initial Permeability, Based on Water 2.8-10 −3 MKM 2 ,
Pressure: 5 Mega Pascal
Composition of System
Phosphate
Permeability of
Surface
Samples
Active
(Core) Based
KF ·
Agent
Corrosion
Pressure
on Water, After
Composition
H 2 O 2 ,
Surfactant,
Inhibitor
Mega
Treatment
Example
Type
Mass %
KHF 2
Water pH
Mass %
Comp %
Temp. ° C.
Pascal
KH, 10 3 MKM 2
1
PPF
10.0
10.0
2
0.8
0.05
70
5
8.59
2
PPF
0.96
20.0
6.5
0.8
0.05
70
5
4.31
3
PPF
20
1
10
0.8
0.05
70
5
5.26
4
Prior Art
0.05
70
5
3.97
Solution 1
1 A prior art, HCL-based, solution was used as a basis for comparison of the solutions of this patent disclosure. The last line (4 th ) of this Table 4 is for that prior art solution.
This patent disclosure sets forth a number of embodiments of the present invention. Those skilled in these arts will however appreciate that various changes, modifications, methods of use, and compositional variations could be practiced under the teachings of this patent without departing from its scope as set forth in the following claims.
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A solution containing a compound having the general formula XF.nH 2 O 2 , wherein X is K + , Na + or NH 4 + and n is an integer from 1 to 3 (e.g., a peroxysolvate of potassium fluoride compound such as potassium fluoride hydroperoxide (KF.H 2 O 2 )) is injected into a subterranean formation in order to increase its permeability, especially with respect to hydrocarbon flow. These compounds serve to dissolve a wide variety of subterranean formation minerals (e.g., siliceous materials as well as carbonaceous materials). Potassium hydrofluoride (KHF 2 ), can be employed with these compounds to produce particularly efficacious subterranean formation treatment solutions.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to a global job distribution system and more particularly to assigning computational tasks according to a selectable set of criteria.
2. Description of the Related Art
Currently large national and multinational corporations rely on high-end computing power to enable and/or efficiently operate their businesses. To satisfy the continually increasing demand for computing power in these organizations, sets of servers and memory units are grouped together into clusters which are commonly known as server farms. These server farms, with their concentration of high performance CPUs, require significant amounts of electrical energy to operate. Energy demand for these server farms is further increased by operating the air conditioning or other mechanical chilling/cooling systems to keep the computing equipment cool. Server energy demand has driven at least one large scale data processing company to locate their newest server farms close to an economical power source such as a hydroelectric dam.
While multi-national companies operate clusters or farms of servers at multiple locations in the U.S. and throughout the world to handle data processing workload, a job assignment to a particular server in a particular cluster is still largely performed on a local basis where the job submitter selects a particular cluster by logging into the cluster, or is part of a group of users assigned to a cluster by geographical region. This workload may come from within a company, from customers accessing company databases via the Intranet or Internet or through data-processing lease agreements where a company without servers leases server capability from an enterprise company. Recently, some attention within the data processing community has been devoted to allocating data processing resource on a global level in order to optimally utilize available resource. In those instances where the workload on the servers is considered when assigning data processing or other computer jobs to a particular server node and server, no consideration is given in the job dispatching process to the sources of energy which will be used to power the server farm (coal, oil, nuclear, hydro, solar), the local cost of energy or the condition of the local energy grid. As a result, job dispatch is not conducted in a manner which can minimize operational costs and/or use the most environmentally friendly energy sources while performing the necessary data processing workload. Furthermore, company data processing operations may come into direct conflict with the needs of the local community during those periods when the electrical grid is under stress.
SUMMARY OF THE INVENTION
To overcome the shortcomings noted above, there is disclosed a global workload assignment algorithm which allows for at least the utilization of the most environmentally friendly power source while processing data, that can balance a customer's requirement for speed in processing data with cost and environmental objectives, that allows for increasing power needs of a data processing center to be adjusted for unusual local conditions which may impact both data processing reliability and community wellness, and/or provide a framework for competitiveness in the area of data processing.
In an embodiment there is disclosed a method of allocating a job submission for a computational task to a set of distributed server farms each having at least one processing entity comprising;
receiving a workload request from at least one processing entity for submission to at least one of the set of distributed server farm;
using at least one or more conditions associated with the computational task for accepting or rejecting at least one of the server farms to which the job submission is to be allocated;
determining a server farm that can optimize said one or more conditions; and
dispatching the job submission to the server farm which optimizes the at least one of the one or more conditions associated with the computational task and used for selecting the at least one of the server farms.
In another embodiment there is disclosed a system of allocating a job submission for a computational task to a set of distributed server farms each having at least one processing entity comprising:
receiving means for receiving a workload request from at least one processing entity for submission to at least one of the set of distributed server farms;
selecting means using at least one or more criteria or conditions associated with the computational task for accepting or rejecting at least one of the server farms to which the job submission is to be allocated;
determining means for providing a server farm that can optimize said one or more conditions; and
sending means for dispatching the job submission to the server farm which optimizes the at least one of the one or more conditions associated with the computational task and used for selecting the at least one of the server farms.
In still another embodiment there is disclosed a computer program product for use with a computer, the computer program product including a computer readable medium having recorded thereon a computer program or program code for causing the computer to perform a method for storing and retrieving data, the method comprising:
receiving a workload request from at least one processing entity for submission to at least one of the set of distributed server farms;
using at least one or more conditions associated with a computational task for accepting or rejecting at least one of the server farms to which the job submission is to be allocated;
determining a server farm that cam optimize said one or more conditions; and
dispatching the job submission to the server farm which optimizes the at least one of the one or more conditions associated with the computational task and used for selecting the at least one of the server farms.
The foregoing has outlined, rather broadly, the preferred feature of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of the claim of the invention. Those skilled in the art should appreciate that they can readily use the conception and specific embodiment as a base for designing or modifying the structures for carrying out the same purposes of the present invention and that such other features do not depart from the spirit and scope of the invention is its broadest form.
BRIEF DESCRIPTION OF THE DRAWINGS
Other aspects, features, and advantages of the present invention will become more fully apparent from the following detailed description, the appended claims, and the accompanying drawings in which similar elements are given similar reference numerals.
FIG. 1 is a view of a high level architecture in which a Global Workload Assignment Engine (GWAE) communicates with a multiplicity of server farms which may be in various geographic locations and maintains a job queue for the assignment of workload to the server farms;
FIG. 2 is block diagram of a Global Workload Assignment Engine (GWAE);
FIG. 3 is a flow chart of the function for weather mitigation;
FIG. 4 is a flow chart of the function of monitoring workload and energy consumption;
FIG. 5 is a chart of information for real time monitor of power, workload, job priority in different server farms as well as cost and green rating determination;
FIG. 6 is a flow chart of a mitigator function which analyzes processing requests from multiple submitters and sends a request-for-bid to each of the entities controlling processing resource; and
FIG. 7 is a flow chart of the function for handling carbon credit trading.
DETAILED DESCRIPTION OF THE INVENTION
There is disclosed a global job and distributed submission system which assigns, and continually reassigns as needed, computational tasks according to a set of criteria of arbitrary number in which one of more of the following are included to manage a complex set of factors which are used for the computation of a computer job assignment. These factors can include environmental cost of power used at all server nodes, knowledge of current carbon credits and the difference in energy consumption, access to weather data bases, access to power supplier databases, and locally specified data compiled at each node which is considered important to the institution (business or other agency).
The computation assignment “engine” and algorithm embodied in program instructions that are executed herein continually examines a variety of factors, some of which are fixed prior to job submission, and others of which are in continual flux. If selected factors go outside a predetermined range for a specified factor, then any or all jobs may be reassigned at that time.
The assignment engine may operate to assign and dispatch workload, and monitor completion and reliability in the following areas:
Environmentally Conscious (Green) Workload Assignment:
The engine works to assign workload to one or more server farms that have the lowest environmental impact as measured by the power source used to power the farm, the server farm power performance product, the expected processing time of the workload and energy requirements for transporting the workload to the processing site.
Weather Risk Mitigation:
The engine may further link with other databases to determine when certain criteria, or conditions have occurred or are about to occur at the server farm location. For example, the farm's processing facilities/resources become at risk due to incipient weather events which may interrupt processing capabilities and/or communication with the processing site. Database links may include an official or private weather forecasting database that routinely issue watches and warnings when severe weather is expected. The engine may down-grade the effected processing resource such that a new workload will not be assigned to the at risk resource and/or the engine may move a presently assigned workload which may be exposed to the event and which has a long run time expectation to an alternate processing location.
Global Security Risk Mitigation:
The engine may also be linked to a security data base(s) such as that supplied by US Homeland Security or individual business firms. This can be used to direct, in a weighted fashion, the processing power to or from areas of relative safety or temporary instability, respectively. As world security conditions dynamically change, this mitigation may be used to enhance or override the other factors feeding data to the global workload assignment engine.
Grid Risk Mitigation:
In certain instances, such as on warm summer days when total demand on a power supplier may approach the capacity of the system and transmission capability is at its limit, the power supplier may be forced to bring on line a less environmentally friendly generating unit and/or power supply interruptions may occur with resulting data loss. When such conditions exist, the engine may further link with a supplier database to determine when generating and transmission resources are approaching their limits and work to divert or re-assign the processing workload to reduce power requirements and improve processing reliability.
Cost Competitiveness:
In a shared network where many processing providers (not just one company) have server farms that may take in one or more workloads from the engine, the engine may further receive data from each processing provider about processing costs in addition to capability, availability and efficiency. These costs may be constant or updated according to the type of workload and organization requesting the processing capacity, etc. The engine may operate to solicit bids for a workload and factor in the bid price for the workload, along with other factors such as the environmental impact, the expected job completion time, etc. in a manner which will manage its operation and balance the cost and/or environmental impact.
Carbon Trading Support:
The engine may further integrate the assignment of a workload to a “green” server resource with a carbon trading system which calculates carbon credits as a function of CO and/or CO 2 level differentials between the energy source used and a base CO 2 level used to calculate a carbon credit/debit.
Referring to FIG. 1 , there is shown a high level architecture in which a Global Workload Assignment Engine (GWAE) 10 communicates with a multiplicity of server farms 12 which may be in various geographic locations and maintains a job queue 18 including one or more submitted work requests for the assignment of at least one workload to the server farms. Each server farm may have multiple computing devices, e.g., servers, each having varying processing capabilities, utilizations, costs and environmental footprints. Likewise, power providers 14 which provide the primary energy source for each farm may have different generation capability, utilization, cost, environmental footprint and interruption risk. The GWAE, through an interface with a number of different databases 16 , considers the environmental footprint, processing and transmission costs along with typical factors in workload assignment such as processing availability and capability to assign a workload to each server farm in a manner which minimizes the environmental footprint, cost, or both. Further the GWAE monitors changing conditions to determine when work in progress should be moved from one server farm to another to further reduce the environmental footprint and/or cost, or to avoid a potential loss of work in progress. In an embodiment it could be set up as a privately run, public accessible resource, or it could be established by a private institution and leased.
Referring to FIG. 2 , there is shown a block diagram of a Global Workload Assignment Engine (GWAE) 10 in accordance with the principles of the invention. The engine dispatches workloads that may be generated at multiple sites/geographies to a number of distributed server farm nodes 12 for execution. A site submitting workload to the GWAE may or may not have native processing resource to execute the workload. Should the submitting site have native capability, the GWAE considers native processing as one alternative in making the workload assignment.
Outgoing workload from each site 22 to the GWAE 10 contains a parameter file which contains parameters including, but not limited to: submitter identification attributes, outgoing 24 and incoming 26 data/file locations, processor requirements, memory requirements, expected execution time, software requirements, etc., used to place a workload on compatible execution platforms. As part of the method taught, the parameter file includes one or more “green” parameters 28 used to drive the assignment of workloads within a spectrum of server farm options that may contain both a mix of friendly and unfriendly environmental footprints. Green parameters weigh the selection of processing resources towards high performance capability, low cost capability or low-environmental impact capability. At its extreme, green parameters may be used to restrict processing to nodes with the lowest environmental impact. Regardless of the green parameter setting, the GWAE 10 operates to provide the lowest environmental impact while satisfying operational, performance and cost constraints.
Workload outgoing from each submitting site may be optionally audited to insure that “green” parameters match the range of settings allowed as a department, project or corporate policy. When implemented, this audit may be conducted by respective processing of data in blocks 30 , 32 , 34 on conductors 36 , 38 , and from 40 , 42 and 44 shown in FIG. 2 in the outgoing data-stream from the submitting location, or as an audit processing module within the GWAE engine itself. In the former case, the site locally controls and updates audit settings for the data stream, and in the latter case, the department, project or company loads parameters to the GWAE and the GWAE differentiates between workloads based on identifier parameters.
The GWAE may operate to initially only receive the parameter information, perform the execution assignment and facilitate data/file communication directly between the submitting and executing sites. Alternatively, all required files may be sent to the GWAE in the initial transfer with the GWAE managing file transfer between the submitting and executing sites.
As additional inputs to the assignment process, the GWAE also receives input 36 , through database query or from other means on each server farm available for workload assignment including, for example, server farm capacity availability, performance capability and energy efficiency. Energy efficiency data may include not only the energy demand/efficiency of the computer servers (primary energy consumption) but the demand/efficiency of the physical plant which supports the computer servers (air conditioners, water chillers, etc.). Database access may be provided in a web-based environment, by a dedicated link or by other means.
The GWAE also receives input 38 , though database query or other means, information on the condition of each power provider which serves one or more server faun nodes in the GWAE system. Information continuously gathered may include, for example, the present load vs. capacity on the providers generation and transmission facilities as well as the present mix of power generation (i.e., fossil fuel, nuclear, solar, hydro, etc.) with percentages. Database access may be provided in a web-based environment, by dedicated link, or by other means. The GWAE may further query a power supplier—server farm cross reference which may be constant or continuously updated to determine which suppliers are contributing power to each server farm if the relation is not implicit for any server farm.
In order to place workloads in a manner which minimizes energy consumption and uses the most environmentally friendly power sources, a number of sub-processes operate within the GWAE.
A job queue within the GWAE operates to handle incoming workloads, for example, on a first-in-first-out (FIFO) basis, holding information on job parameters, green and other information necessary for assignment.
The GWAE monitors parameters 40 from each server farm, calculates and updates the energy consumption and environmental footprint per standardized unit of processing capacity based on the performance of available servers, the power those servers demand and the secondary power required to run the facility. Server farms are ranked 44 according to energy consumption in conjunction with green parameter performance/green weight in the parameter file. Further, the GWAE applies the calculations to the expected processing requirements for the request to calculate the total energy requirements. Expected processing requirements may be entered as parameter inputs or calculated based on past history for file sizes, software called, customer history, etc. Availability of servers within each server farm is used to further augment the ranking such that workload is not assigned to nodes that lack sufficient capacity.
While energy consumed may be principally driven by the executing server farm for large processing jobs, smaller jobs may use transmission energy which is significant in proportion to the processing energy when movement of data across geographies is considered. Because of this the GWAE estimates the energy required to transfer workload from the submitting site to the executing site for each assignment possibility. For small jobs, less total energy may be consumed when jobs are executed locally on less efficient systems than when the data is transmitted to a distant location.
In addition to ranking the server farms, the GWAE also ranks power suppliers 42 . Suppliers operating from renewable resources are ranked above suppliers operating from fossil fuels. Where non-renewable sources are employed, the sources are ranked based on generation efficiency and environmental footprint per unit of energy produced. Where suppliers operate using a mix or renewable and non-renewable sources, supplier ranking is influenced by the percentage mix of the sources. Generation mix may further be used to calculate cost per unit of energy as well as environmental footprint for factoring into workload assignment. Ranking may be further augmented using preferences within the spectrum of renewable sources. For instance, solar or wind energy may be preferred over hydro energy due to concerns over water reserves, etc.
The GWAE further correlates ranked server farm data 44 , FIG. 2 , with ranked power supplier data from power suppliers 46 , FIG. 2 , to determine the server farm which best meets the submission parameter criteria. Server farms with the lowest environmental impact may be identified based on supplier and faint ranking/correlations 43 as well as data transfer energy estimation. Likewise, solutions with the lowest cost or the highest performance can be identified.
Workload assignment within the GWAE operates with ranking functions such as the one described above in conjunction with the green parameters associated with the workload. Workloads (jobs) marked for assignment on only those computing resources which are 100 percent renewable will be placed on nodes which have the required energy source profile. If no initiators are available, the jobs will remain in the queue until a resource is available. A workload not marked for 100 percent renewable computation will be assigned to the most-environmentally friendly resource available that meets the performance constraints at an assignment time. If a resource that is 100% renewable powered is available and no job requiring this profile exist in the queue, this workload is assigned to the fully renewable resource unless the resource does not meet the performance or other workload requirements. Should a new workload requiring the renewable resource be submitted, a workload which does not require fully renewable processing may be checkpointed and moved to the next available initiator as ranked. Checkpoint is defined as Flagging a job so that it is an indication for the job to be moved. Similarly, a workload originally assigned to a less environmentally friendly node by the GWAE may be moved to a more friendly node should initiators become available. Movement decisions may be based on an expected resource required to complete the workload as opposed to that required to checkpoint and transport the required files to another node, or other factors as well as initiator availability. As a default, the GWAE always works to assign a workload to the lowest environmental footprint solution considering energy consumption for transport and processing as well as the energy mix used at the processing site (in addition to performance or other installation requirements). For small jobs, the best solution as determined by the GWAE may be to run the job locally to avoid transport energy consumption. As a default, the GWAE operates to minimize the environmental footprint for the workload unless the performance/cost parameters make the execution on green resource impossible, in which case the GWAE operates to satisfy job parameters in the order of their importance as weighted in the parameter file.
Once an assignment is made, the GWAE either operates as an intermediary transferring required files from the submitting to the executing site or operates as a facilitator passing instruction to each of the submitting and executing sites for direct communication. Further, the GWAE may monitor the server farm 40 and workload status 48 , FIG. 2 , and communicate with the submitter and executor to facilitate any checkpoints or workload moves.
Weather Risk Mitigation
As disclosed above and shown in the flow chart of FIG. 3 , the method performed by the GWAE utilizes a number of databases to incorporate real time parametrics for server farms and power suppliers through web-based links, dedicated links or by other means into the workload placement algorithm. In another embodiment, the method may additionally comprise adaptive job assignment based on impending environmental events which may disrupt workload processing at any server farm or communication between a farm and the GWAE and/or the submitting node. Examples of environmental events that the GWAE may operate are watches, warnings, occurrences of hurricanes, tornadoes, flood or winter storms, although other events may be considered.
Referring to FIG. 3 , to provide weather risk mitigation, flow chart 302 shows how the GWAE links to a weather prediction database 304 managed by a public or private entity, examples of which are National Weather Service (NOAA), Environment Canada, etc. to retrieve regional forecasts for geographic zones which contain server facilities and/or critical power production facilities. Each forecast may contain watches and warnings for severe weather events which may affect the ability to process one or more workloads or deliver power to a server farm along with the event type, probability of the event, and time frame for the event. The GWAE uses the additional information obtained from or accessed via the weather risk link, along with other server farm power supplier and job submission parameters to confirm initial job submission assignment by the GWAE (step 306 ). The mitigation method may comprise calculating expected completion time for workload on the selected node (step 308 ) and examining the forecast as provided by database 304 for the estimated processing timeframe (step 310 ). Once the GWAE determines that workload processing time will not overlap an at risk time period (step 312 ) that workload is eligible for submission to the farm in question. Thereafter, it is determined if the weather risk has increased based on the completion time on the job (step 314 ). If yes (YES; step 314 ), the job is checkpointed and potentially reassigned (step 316 ). If, however, weather risk to the workload has not substantially changed, (NO; step 314 ), the job is run on the present server to completion (step 318 ) or until a degradation in the weather forecast is received (step 314 ). Furthermore, weather information is routinely monitored for a defined set of adverse (or worsening) conditions, which would have the potential to disrupt the data processing. These changes in weather, once a workload is submitted to the farm and adverse changes in weather condition, may trigger checkpointing and possible movement of a workload to alternate farms. While the at-risk node may be under-utilized with regard to long running workload, the GWAE may preferentially route short run workloads to the at risk node in the interim period. The method may further comprise auditing an existing work load on the server node to determine if any workload is expected to still be running at the onset of the risk period, determining whether to checkpoint and move an affected workload from the affected node, and using the GWAE to reassign the checkpointed workload. Reassignment may be performed using a separate prioritized re-assignment queue within the GWAE or by prioritization within the submission queue of the GWAE. Additionally the method may further comprise GWAE prediction of outage probability based on the watch/warning presented, past history and, in some instances, more detailed weather data with a GWAE decision point for mitigation based on prediction.
While not considered a weather event, and not always predictable, other natural disasters such as earthquakes, volcanic activity and tsunamis may be mitigated in the same manner assessing risk time frame and diverting workload to non-compromised processing resources.
Grid Risk Mitigation
As demands for energy increase faster than power suppliers can bring new power generation and transmission facilities, suppliers have instituted programs that notify the industry and the public during periods where peak energy requirements are estimated to be close to the maximum generation/transmission capability of the geographic area. The goal of these programs is to request conservation/reduction of utilization in order to prevent either rolling blackouts or utilization of short-term, less-efficient (dirtier) power supplies which drive up the cost/environmental impact.
As a corollary, server farms themselves may face periods of time when the energy consumed by the servers and the physical plant (cooling, etc) approximate or exceed the intended maximum designed power capability for the facility due to increases in capacity, transition to higher-power servers, or summer temperature extremes. In each case, completion of the workload currently running or queued for processing on the affected server farm becomes at risk.
Referring to FIG. 4 , there is shown a flow chart of a function operation 402 within SF 1 , there being a similar function operation within each server farm to monitor workload and energy consumption and communicate status back to the GWAE through one or more links. To pick the correct variable from FIG. 5 , for that SF, the Flow in FIG. 4 will actually have x 2 , dx 2 and y 2 for a SF 2 flow. The flow in FIG. 4 will actually have xn, dxn and yn for SFn flow as defined in FIG. 5 . Initially, after job 1 is added to SF 1 (step 404 ), the function executed at a device within SF 1 determines if y 1 is greater than x 1 where energy consumption (summation of processing energy, cooling energy, etc.) is monitored as y 1 and where X 1 is the desired normal power consumption maximum for the facility. If y 1 is less than x 1 (NO; step 406 ) the function proceeds to set SF 1 availability flag=1 to accept future jobs (step 408 ). Thereafter, the function processes jobs at optional processing capability (step 410 ), then accepts a next job if available (step 412 ), and returns to step 406 . If, however, at step 406 , y 1 is greater than x 1 (YES; step 406 ), the process determines if y 1 is greater than x 1 plus dx 1 where dx 1 represents the allowable short term power consumption above the normal maximum x 1 . If it is not, (NO; step 414 ) the process sets SF 1 availability flag to “0” to not accept future jobs (step 416 ), then transfers a low priority job to GWAE for reassignment (step 418 ) in order to return to y 1 <x 1 , and returns to step 406 . If, at step 414 the function determines that y 1 is greater than x 1 plus dx 1 (YES; step 414 ), the process checkpoints all workloads to ensure loss of intermediate results does not occur (step 420 ), then processes jobs at a lower processing capability (step 422 ) and advances to step 416 .
Restating the above described function of grid risk mitigation, a workload assigned by the GWAE to a given SF 1 is added to the processing workload, and energy consumption is monitored as “y 1 ”. If y 1 is below the rated threshold “x 1 ” for the facility, the SF communicates back to the GWAE that it is available for an additional workload through the server farm database (see FIG. 5 , upper left block, lines 1 and 2 ). Once the amount of the workload forces y 1 to be greater than threshold x 1 , the SF communicates back to the GWAE that it has reached/exceeded its designed power consumption and that it is no longer available for any additional workload.
Energy consumption y 1 is checked against a second threshold “x 1 +dx 1 ” to determine if the total energy consumption is below or above the worst case (short term) maximum for the facility. If y 1 is below x 1 +dx 1 the SF in communication with the GWAE begins to checkpoint lower priority workload for re-assignment to other SFs by the GWAE. Prioritization of the workload is maintained in the job priority database (see FIG. 5 , lower left block). If y 1 is above x 1 +dx 1 the SF begins to checkpoint all workloads in order to ensure that intermediate results are not lost. Workloads may continue to be processed on the SF at lower processing capability (speed) in order to reduce power consumption below the short term maximum as a lower priority workload is reassigned by the GWAE in order to bring the server farm energy consumption to y 1 <x 1 .
Referring to the chart of FIG. 5 , the GRID INFO DATABASE comprises 3 databases—a server farm database, a Job priority data base and a Power provider database. Server Farm database keeps track of the maximum power handling capability, a tolerance indicating power level (red zone range) and Real time power consumption for EACH SF. Job Priority database keeps track of the real time individual jobs being processed by each SF and the priority of jobs under each SF. Power Provider database: the PP database keeps track of EACH Power provider's (PP) Green rating, Availability status to each of the SF, real time power supplied to each SF, Usage cost to each SF and power transmission cost to each SF. The database also keeps track of Each SF's total power contributed by the different PPs, Net green rating of each SF, and Net usage & transmission cost of each SF. To insulate the workload from power supply/transmission stresses, the databases from which the GWAE gets parameters for workload assignment are augmented to include messaging from suppliers/transmission operators on conditions and forecasting as the digital equivalent of “electrical load day” designations commonly provided to inform power customers of peak loading conditions. The power provider database provides, along with green rating % and cost information used in workload assignment above, information on power supply/transmission availability (capability, use) for each of the one or more power providers for each server farm. When power supply/transmission margins reach a threshold, the GWAE may act to prevent additional workload on the SF in question and possibly move one or more workloads in progress to other SFs to reduce the load on the suppliers/grid and insure that the workloads are completed.
Referring to FIG. 5 , there is shown an information chart of an example of the result of a power provider ranking algorithm calculation of Net Green Rating (NETGR_SF 1 ) for Server Farm One (SF 1 ) where
PP 1 with 50% Green Rating provides 300 Kwatts to SF 1 ; PP 2 with 20% Green Rating provides 200 Kwatts to SF 1 ; PP 3 is not available for SF 1 ; and PP 4 with 10% Green Rating provides 500 Kwatts to SF 1 .
Thus, the total power supplied by three Power Providers, PP 1 , PP 2 and PP 4 to Server Farm one (SF 1 ) is NETPWR_SF 1 =300K+200K+0+500K=1000 Kwatts.
The Green Rating (GR) of SF 1 =NETGR_SF 1 =(300 Kwatts/1000 Kwatts)×50%+(200 Kwatts/1000 Kwatts)×20%+(500 Kwatts/1000 Kwatts)×10%=15%+4%+5%=24%
Cost Competitive Environment
The GWAE is not limited to distributing the workloads amongst server farms controlled by a single public or private entity, but may be expanded to perform gateway services to server farms owned by multiple companies or governments. When heterogeneous ownership of processing capacity exists, it is recognized that management of each server farm may be done in a competitive manner to obtain workload share. To enable competition between multiple server farm owners in a GWAE environment, the GWAE is programmed to provide a mitigator function 602 ( FIG. 6 ). The mitigator function (at step 608 ) analyzes processing requests from multiple submitters (requestor(s) 604 ) and sends a request for bid to each of the entities controlling processing resources (server(s) 610 ). The request may contain information on hardware and software requirements, job size, performance, resource and/or green constraints. Each entity (server(s) 610 ) may bid on the workload in an effort to secure it. The bid may include quotes for one or more of processing cost, green processing capability, information transmission cost, processing time, or carbon credit earnings. The GWAE may select (step 612 ) a processing provider (server choice 616 ) for each requestor 614 for the subject workload based on any one factor or a weighting of factors to satisfy the workload submitter's requirements and optimize the processing constraints to the submitter's requirements. The GWAE mitigate function may limit the set of processing providers from which it requests bids based on present server farm workloads, software or hardware limitations, green factors, location factors, weather/grid factors or other factors to which the GWAE has knowledge. Within the GWAE mitigate function, processing providers may have the ability to target competitiveness to certain classes of customers and may have different response templates for different submitting customers, types of work, etc.
Integration into a Carbon Trading System
In another embodiment, the GWAE is enabled to handle carbon credit trading. Carbon credit trading is a rapidly evolving system where companies can purchase carbon credits to offset activities that produce carbon pollution above a threshold and/or earn carbon credits when activities produce carbon pollution below a threshold. The net effect of the carbon credit system is to cap/manage the amount of carbon being released to the environment and increase greener operation. For many industries that are data management or data processing intensive, primary and secondary energy used in processing IT workloads is a significant percentage of their carbon output and represents an opportunity for carbon trading.
In a GWAE adapted for carbon credit trading (CCT), new workload requests may be audited for information on whether the submitting entity is participating in CCT. If the entity is not participating in CCT, or participation is not mandated, submission through the GWAE operates as detailed above. If CCT is enabled, carbon credit (CC) information about the submitter may be audited to obtain the present CC balance, with the GWAE acting as a bookkeeper for credits. Should a positive CC balance exist, submission through the GWAE operates as detailed above, and the GWAE submits the workload based on cost, time and environmental parameters associated with the workload request, and the carbon trading credit for the newly submitted workload may be either positive or negative. The CC banking query may be based on only previous history, or include an estimate of carbon credit requirements should the requested workload be performed on a non-environmentally friendly server farm. Should a negative balance exist, the GWAE will query the submitter, or submitter database, to determine if carbon credits should be purchased to null the deficit, or estimated deficit. If CCs are purchased, the job assignment continues as if a positive CC balance existed. If additional CC purchases are refused, the GWAE limits submission opportunities for the requested workload to only those servers that will produce a net positive CC balance. Once a workload is submitted, the GWAE monitors the status of the workload and when the workload is completed, a calculation of CC earning/cost is made based on workload placement, run time, transmission costs etc., and GWAE book-keeping is updated accordingly. The GWAE CCT function operates to maintain a CCT neutral or alternatively, a CCT positive balance over time.
Referring to FIG. 7 , there is shown a flow chart of the function 702 for handling carbon credit trading. A request for carbon credit trading is received, (step 704 ), where it is determined if the request is a new request. If the request is not a new request, (NO; step 704 ), the function determines if the job is finished (step 706 ). If the job is not finished (NO; step 706 ), the function returns to step 704 . If the job is finished (YES; step 706 ), the function calculates credit (step 708 ), adds the calculated credit to the balance (step 710 ), and returns to step 704 . Returning to step 704 , if the request is a new request (YES; step 704 ), the function determines if the balance is positive (step 712 ). When the balance is positive (YES; step 712 ) the function then advances to “submit to best matched server” (step 714 ) and then proceeds to step 704 . Selection of the best matched server in step 714 may be restricted to nodes which result in addition to the positive credit balance or may add or subtract from the balance dependent on submission parameters for the workload. If the balance is not positive (NO; step 712 ) the function advances to purchase credit (step 716 ). If credit is not to be purchased (NO; step 716 ), the function advances to “submit only to green server” (step 718 ) and then continues to step 704 . If, however, credit is purchased (YES; step 716 ), the function purchases credit (step 720 ), adds the credit to balance (step 722 ) and then advances to step 714 .
In one embodiment of the invention jobs are assigned one at a time to a Server Farm (SF). In this embodiment, a job is taken off the queue and assigned to whichever server farm that best meets the criteria of the job (e.g. jobs with green preferences are assigned to green servers).
Still another embodiment considers all jobs in the queue that have not been assigned to a server farm. An embodiment of this method uses linear programming to assign the jobs in combination with alternative job assignment methods. The model formulation handles a single job on a single processor (or server machine) at any given time and allows for multiple jobs within a time period as long as the total time spent by the jobs in that time period does not exceed the duration of the period. This can be extended to machines with multiple processors (ability for a machine to handle multiple jobs) by treating the processors within the machine as individual machines which compete for the same resources. With this embodiment a set of jobs can be handled only by a specific set of servers (e.g. some jobs can be handled only by green servers). This can be achieved either by the resources requirements of the jobs or job preferences.
The linear programming (LP) embodiment can be composed of an objective function that defines a measure of the quality of a given solution, and a set of linear constraints. The types of equations used in job assignment models can include:
1. Backorder Constraints which ensures that each job not assigned in one period is backordered to the next period. (must be assigned in a subsequent period) 2. Resource Capacity Constraints, which ensure that the capacity available for processing job activities including capacity used for jobs already assigned is not exceeded. 3. Assignment Constraints, each job is assigned to one server or server family. The total time jobs spend in a period cannot exceed the duration of the period.
An LP formulation which can be used is provided below in the form familiar to those practiced in the art; i.e., definition of subscripts, definition of objective function coefficients, definition of constants, definition of decision variables, LP formulation or equations.
Definition of Subscripts
j—Time period
m—Server or Server farm (could be a single processor)
k—Job k (job arrival number)
w—Server resource e.g. such as memory, disk space, etc.
Definition of Objective Function Coefficients
PRC mk —cost of processing a job k on a server m.
BC kj —penalty for inability to assign job k by the end of period j.
Definition of Constants
REQ kw —Resource requirements of job k and resource type w.
RT km —Run time of job k on server m.
R jmw —Total Resource for type w available for processing jobs that have not yet been assigned to server m during time period j.
BS j —bucket size (BS) duration in period j (e.g. number hours in period j).
Definition of LP Decision Variables
X jkm —Assign job k to SF m in period j. (binary, takes values 0 or 1)
B jk —Backorder of job k in period j. B jk =0 if job k assigned by period j; 1 otherwise
Y jkm —Total time job k spends running on server m in period j.
LP Equations or Formulation
The following minimizes the objective function subject to the constraints shown below.
Objective Function:
Minimize:
∑ j ∑ m ∑ k PRC mk X jkm + ∑ j ∑ k B jk BC jk
Subject to:
Backorder Constraints:
Ensures that B jk =0 if job k assigned by period j, 1 otherwise
B jk = B ( j - 1 ) k - ∑ m X jkm ∀ j , k
j=Time period (j=1, 2 . . . N where N is number of time periods) and where
B 0k =1
Capacity Constraints:
REQ kw *X jkm ≦R mjw ∀j,w,k,m
Assignment Constraint: Each job is assigned once.
∑ j ∑ m ∈ S ( k ) X jkm = 1 ∀ k
Where S(k) is the set of servers that can handle job k
The following two constraints ensure that once a job has begun processing on a server it completes in the earliest possible period and that the total processing time at a server does not exceed the time available:
∑ r = v v + ⌈ RT k BS ⌉ Y rkm = X vkm RT k ∀ k , m
Where BS is average period size between periods v and
v
+
⌈
RT
k
BS
⌉
∑ k Y jkm ≤ BS j ∀ j , m
Non-Negativity Constraints:
all X i,j . . . ≧0, where X is a generic decision variable and i, j etc. represent generic subscripts.
The model formulation above can be solved using an LP solver (such as COIN or CPLEX solver) or a rule based heuristic.
The various method embodiments of the invention will be generally implemented by a computer executing a sequence of program instructions for carrying out the steps of the method, assuming all required data for processing is accessible to the computer. The sequence of program instructions may be embodied in a computer program product comprising media storing the program instructions. As will be readily apparent to those skilled in the art, the present invention can be realized in hardware, software, or a combination of hardware and software. Any kind of computer/server system(s)—or other apparatus adapted for carrying out the methods described herein—is suited. A typical combination of hardware and software could be a general-purpose computer system with a computer program that, when loaded and executed, carries out the method, and variations on the method as described herein. Alternatively, a specific use computer, containing specialized hardware for carrying out one or more of the functional tasks of the invention, could be utilized.
As will be appreciated by one skilled in the art, the present invention may be embodied as a system, method or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, the present invention may take the form of a computer program product embodied in any tangible medium of expression having computer-usable program code embodied in the medium.
Any combination of one or more computer usable or computer readable medium(s) may be utilized. The computer-usable or computer-readable medium may be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM) or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a transmission media such as those supporting the Internet or an intranet, or a magnetic storage device. Note that the computer-usable or computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via, for instance, optical scanning of the paper or other medium, then complied, interpreted, of otherwise processed in a suitable manner, if necessary, and then stored in a computer memory. In the context of this document, a computer-usable or computer-readable medium may be any medium that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-usable medium may include a propagated data signal with the computer-usable program code embodied therewith, either in baseband or as part of a carrier wave. The computer usable program code may be transmitted using any appropriate medium, including but not limited to wireless, wired, optical fiber cable, RF, etc.
Computer program code for carrying out operations of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, though the Internet using an Internet Service Provider).
The present invention is described above with reference to flow chart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flow chart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable medium produce an article of manufacture including instructions means which implement the function/act specified in the flowchart and/or block diagram block of blocks.
The computer program instruction may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
Although a few examples of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes might be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.
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A system and method of allocating a job submission for a computational task to a set of distributed server farms each having at least one processing entity comprising; receiving a workload request from at least one processing entity for submission to at least one of the set of distributed server farms; using at least one or more conditions associated with the computational task for accepting or rejecting at least one of the server farms to which the job submission is to be allocated; determining a server farm that can optimize the one or more conditions; and dispatching the job submission to the server farm which optimizes the at least one of the one or more conditions associated with the computational task and used for selecting the at least one of the server farms.
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FIELD OF THE INVENTION
The invention concerns a process for the manufacture of a coating bar for a bar coater, wherein the coating bar is supported substantially over its entire length as revolving in a cradle fixed to the frame of the coater.
The invention is further related to a coating bar for a bar coater, wherein the coating bar is supported substantially over its entire length as revolving in a cradle fixed to the frame of the coater.
BACKGROUND OF THE INVENTION
A bar coater is employed in coating of paper, particularly in cases where the possibility exists that the coating blade in a blade coater will produce streaks in the paper surface. In order to avoid this problem, attempts have been made to prevent such streaks using a coating bar. As a rule, the coating bar is rotated in the direction opposite to the direction of running of the web, at a rate of from about 10 to about 600 revolutions per minute. Coating bars are provided with suitable drive gears to rotate the bar, and in wide machines the bars are usually provided with drives at each end of the bar to avoid torsional vibrations.
When a bar coater is used, the coating process itself can be arranged, e.g., so that the coating agent is scraped off the web surface by means of the coating bar. A bar coater may also be constructed as a so-called short-dwell unit, wherein the coating agent is introduced into a coating-agent chamber. A coating agent chamber is defined by a front wall, the coating bar, and by the base to be coated itself, which base may be the face of a counter roll, the paper web, or equivalent.
The coating bar is mounted such that it is able to revolve in a cradle made of a suitable material, such as polyurethane. Normally, the bar is supported in the cradle over its entire length. A groove for water is usually provided in the cradle, in connection with the bar. The water circulates in the groove in order to lubricate, to cleanse and to cool the coating bar.
Traditionally, a hard-chromium plated wire bar has been used. For example, the bar doctor in the SYM-SIZER size press (trademark of Valmet Paper Machinery, Inc.), a size press used for surface sizing and coating of paper operated by the principle of short-dwell coating, has traditionally been a bar around which a stainless-steel wire has been wound. Hereupon the bar has been hard-chromium plated to improve its resistance to wear. The wound wire forms regular slots in the bar surface, by means of which slots the quantity of size to be applied to the roll face can be regulated. The size of the slots and, consequently, the quantity of size can be regulated by using different wire diameters.
Drawbacks of such a wire bar include short service life, tendency of the wire to be broken and thereby to enter into the nip, with resulting damage to the roll coating and a standstill. Further problems include poor wear resistance of the bar, as well as unsuitability of the bar for thermal and thermo-chemical coating processes, because the wire may be broken during the process. Further difficulties arise in the quality of the coating process, because the coating does not become uniform with long bars and does not adhere properly.
A bar doctor composed of ceramic bushings is also known in the art, by whose means attempts have been made to solve the above problem of wear resistance. The success of such attempts has been unsatisfactory in practice. Grooved bars having a hard-chromium plating on their surface have also been employed.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a coating bar which does not have the drawbacks of the bars mentioned above and which has a higher resistance to wear.
These objectives and others are achieved by the present invention, which relates to a coating bar which is profiled and surface-treated by boronizing.
One aspect of the coating bar in accordance with the invention for a coater is that the coating bar is profiled and its surface layer contains a layer of ferrous boride (FeB/Fe 2 B).
The concentration of boron in the layer of ferrous boride is preferably from about 2% to about 20%, preferably at least 8%, by weight. For example, a particularly preferred embodiment, the surface layer of the coating bar includes 16.23 percent by weight FeB compound and 8.83 percent by weight Fe 2 B compound.
The boronizing can be carried out either by means of a powder package process in the horizontal or vertical position, or by means of a paste process in a separate vacuum oven.
Boronizing by the powder package process utilizes boron carbide. The boron is diffused into the surface layer of the bar. This is accomplished, for example, by submerging in an oven preferably at a temperature from about 800° C. to about 1050° C.
The present invention is also related to a bar construction which is substituted for the above-described hard-chromium plated wire bar. In the invention, a smooth bar is provided with grooves by, for example, rolling. Thereafter, the bar is surface-treated by boronizing. The boronizing process itself is a well known surface treatment process based on diffusion, by whose means the composition of the surface layer on the steel is modified. In the surface layer, a hard layer of ferrous boride (FeB/Fe 2 B) is formed by means of treatment at a high temperature, e.g. from about 800° C. to about 1050° C.
Because the surface-treatment process is based on diffusion, the grooves applied to the bar before the boronizing treatment do not cause problems. Consequently, a uniform hard and wear-resistant surface layer of a thickness of from about 5 microns to about 250 microns is obtained. In a preferred embodiment, the thickness of the surface layer is from about 15 microns to about 25 microns.
A wire bar cannot be boronized, because the wire would already be broken in the boronizing treatment. On the other hand, a grooved bar can be chromium-plated, but its resistance to wear is inferior to that of a boronized bar.
The hardness of a conventional hard-chromium plated bar is of an order of from about 700 to about 1100 HV units, whereas by means of a boronized bar in accordance with the invention, hardnesses of about 1100 to about 1700 HV are readily attained. Preferably, a hardness of about 1400 to about 1700 HV is achieved.
The reason for discarding a bar is either breaking of the wire or the fact that the size quantity no longer meets the requirements, as the profile becomes lower and the size volume is reduced. Typical service lives of bars with conventional hard-chromium coatings vary from a few hours to 3 or 4 weeks.
The rate of wear is usually approximately inversely proportional to hardness. The life of the boronized bar has greater hardness than a bar with a hard-chromium plated face. With the greater hardness of the boronized bar, a longer service life is obtained.
In general, the coater operates so that a regular volume remains between the bar and the roll. The volume has been provided either in accordance with the prior art e.g., by winding a wire around a 10 mm base bar, or in the manner suggested in the present invention, by forming a regular groove pattern onto a, e.g., 10 mm bar, of which there may be a number of different types.
By virtue of the combination of the invention, incorporating the prior-art surface treatment process (boronizing) with a grooved bar substituted for the prior-art wire bar, a service life is attained which is longer than with the prior-art solutions.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, the invention will be described by way of example with reference to the figures in the accompanying drawings.
FIG. 1 is a schematic sectional side view of a bar coater in which a coating bar in accordance with the invention is employed.
FIG. 2 shows an embodiment of boronizing in accordance with the invention wherein the boronizing is carried out by means of the powder packing process.
FIG. 3 shows an embodiment of boronizing in accordance with the invention wherein the boronizing is carried out by means of the paste process.
FIG. 4 is a schematic illustration of a coating bar in accordance with the invention.
FIG. 5 is a schematic illustration of different profiles of a coating bar in accordance with the invention.
DETAILED DESCRIPTION
FIG. 1 shows an exemplifying embodiment of a bar coater in which the bar in accordance with the invention can be applied. In FIG. 1, the coater is denoted generally with the reference numeral 10. The coater 10 is a bar coater, in which the coating bar 13 is in the embodiment shown in FIG. 1, fitted against the paper or board web W that runs on the face of a backup roll 14.
The coater 10 shown in FIG. 1 is a coater of the so-called short-dwell type, wherein the coating agent is introduced into a coating-agent chamber 11, which is placed before the coating bar 13 in the direction of running of the web W. The coating-agent chamber 11 being defined by said coating bar 13, by the web W, by the front wall 12 of the coating-agent chamber 11, and by lateral seals (not shown). The coating-agent chamber 11 is pressurized in any manner known in the art, and out of the chamber 11 an overflow of the coating agent is arranged through the gap 15 between the front wall of the coating-agent chamber and the web W.
The coating bar 13 is fitted in a cradle 18 made of a suitable material, e.g. of polyurethane. The cradle supports the coating bar 13 over its entire length. The coating bar 13 is provided with a purposeful drive gear, by whose means the coating bar 13 is rotated in the direction opposite to the direction of running of the web W. The cradle 18 of the coating bar 13 is fitted in a support 16, and both the cradle 18 and the support 16 are together fixed in a holder 19 mounted on the frame of the coater 10. Moreover, on the support 16, underneath the cradle 18, a loading hose 17 is provided, by whose means the coating bar 13 can be loaded in a desired manner against the web W. A water groove 5 is provided in cradle 18, which is placed in connection with the coating bar 13. The water circulating in the groove lubricates, cleanses and cools the coating bar 13.
In the powder packing process illustrated in FIG. 2, in the horizontal position, the bars 3 are submerged in a vessel 2 made of stainless or fireproof steel. The vessel 2 contains activated boron carbide powder 5. Thereafter, the vessel is placed in an oven, which consists of a base 4 made of refractory bricks and of a cover 1. The cover 1 is made of fireproof ceramic fibre material, into which electric resistor units 6 have been embedded. The temperature of the resistor units 6 is regulated by means of a separate control unit. The temperature is raised by means of the resistor units to a temperature from about 800° C. to about 1050° C., at which temperature the diffusion of the boron into the steel takes place.
The particle size of the boronizing powder is in the range of from about 10 microns to about 1500 microns, depending on the groove size on the bar to be boronized, on the base material, and on the required surface quality. The reaction time varies from 10 minutes up to 30 hours, depending on the desired thickness of the hard layer. The type and the alloying of the base material also affect the reaction time.
The boronizing powder is available commercially, e.g., under the name EKabor, which is a registered trademark of Messrs. Elektroschmelzwerk Kempten GmbH. The boronizing powder consists of activated boron carbide, B 4 C, whose boron concentration is from about 40 to about 70%. In this regard, reference is also made to Boronizing by Alfred Graf von Matuschka, Carl Hanser Verlag, Munich, Vienna, 1980, 97 p.
The powder packing process in the vertical position take place in a way similar to the horizontal processing, but therein the bars, the vessel, and the oven are placed vertically. In this case, it is possible to control the linearity of the bars more efficiently.
In the paste process illustrated in FIG. 3, a boronizing paste is spread onto the faces of the bars either by spreading, spraying, or by submerging the bars into a container filled with paste. Thereafter, the bars 3' are placed vertically in a stand 8. The stand is placed into a shield-gas oven under vacuum, said oven consisting of a fireproof or stainless frame 4' and of an insulation 1' of fibre material, into which resistor units 6' have been embedded. The required vacuum is sucked by means of a vacuum pump 7, and the shield-gas atmosphere is provided in the oven by means of nitrogen or argon 9. A shield-gas atmosphere is indispensable in the boronizing paste processing.
It is an advantage of the vertical treatments that the bars can be made to remain straight, because in the vertical position, owing to the bar's own weight, at a high temperature, a creep, i.e. a time-dependent deformation, takes place. The creep (<0.01% per 100 hours) produced as a result of the vertical treatment is so small that it does not affect the geometry of the bar profile Owing to the vertical position, the direction of the deformation is always the same, such that substantially no distortions arise. On the other hand, distortions arising from creep in the horizontal position are more probable, but in the horizontal processing they have been reduced by applying an axial force to the bar submerged in the powder during the boronizing treatment.
Boronizing paste also commercially available, e.g., under the registered trade mark Ekabor of said Messrs. Elektroschmelzwerk Kempthen GmbH. The boronizing paste is also a product based on boron carbide.
In FIG. 4, a preferred embodiment relating to the threaded area of a coating bar is shown. A detailed illustration of the thread profile is shown in FIG. 5. The groove pattern passes around the bar as spiral-shaped, having from about 1 to about 7 starts or no pitch. The pitch of the thread is understood as meaning the distance in the axial direction of the bar that corresponds to one revolution.
The thread profile passing around the bar can be defined by means of the parameters r1, r2, φ1, φ2, H1, H2, and D:
______________________________________φ1 area (angle) of effect of the radius of thread ridgeφ2 area (angle) of effect of the radius of thread valleyr1 radius of ridger2 radius of valleyH1 height of ridge from the axial base line of the bar, determined by the radius r1H2 depth of valley from the axial base line of the bar, determined by the radius r1D distance in the axial direction of the bar equalling half a revolution.______________________________________
The bar doctor in accordance with the invention is grooved by molding, such as rolling or cutting, before the boronizing treatment based on diffusion, and after the shaping it has been boronized. The surface quality achieved on boronizing is so good that it does not require any major finishing. Owing to the smooth hard surface layer, the wear resistance is substantially higher than that of a conventional bar, and risks of operation, such as tendency of the wire to be broken, have been substantially eliminated.
The bar is rotated by the intermediate of a cardan shaft by a motor in a direction opposite to the sense of rotation of the roll. During operation, the bar contacts the roll coating, which may be abrasive. Moreover, the size to be applied contain abrasive particles, which wears off some of the profile of the bar in the course of time.
An advantage of the present invention over conventional coating bars include high hardness and wear resistance of the surface, because of which the service life is long, because the replacement of a bar causes no standstills. Another advantage of the present invention is that it provides evenness of the hard surface layer, as the process is based on diffusion. Another advantage is that it provides good adhesion of the hard surface layer, as the surface layer consists of the base material and there is no separate coating/base material interface.
Furthermore, breaks of wire have been eliminated, because there is no wire. However, a potential drawback is the quality (smoothness) of the surface, which is probably inferior to the smoothness of a hard-chromium plated surface.
The invention has been described by way of example with reference to the Figures in the accompanying drawing The invention is, however, not confined to the exemplifying embodiments shown in the figures alone, but a number of variations are possible within the scope of the inventive idea defined in the following patent claims.
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Process for the manufacture of a coating bar for a bar coater, wherein the coating bar is supported substantially over its entire length revolving in a cradle fixed to the frame of the coater. The coating bar is profiled and surface-treated by boronizing.
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RELATED APPLICATIONS
This application is a Continuation of U.S. patent application Ser. No. 11/038,449 filed Jan. 18, 2005, now U.S. Pat. No. 7,054,480 which is a Continuation of U.S. patent application Ser. No. 10/155,255, filed May 22, 2002, now U.S. Pat. No. 6,862,491, each of which is incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to the field of semiconductor wafer inspection and, in particular, to a system and method for optically monitoring variations in the integrated-circuit fabrication process.
BACKGROUND OF THE INVENTION
The process of fabricating integrated circuits (ICs) on a semiconducting substrate, such as a silicon wafer, is highly complex and consists of a large number of steps. Each step involves many process parameters that must be tightly controlled in order to obtain consistent and accurate results. There are, however, physical factors that may cause unintentional deviations in the process at any step.
Such factors may be due to variations in the substrate itself, to slight mechanical and optical inaccuracies in the processing equipment (such as defocusing due to slight misalignment), to dust and dirt and to environmental variations. The deviations in the process may be a function of time that is between successive wafers, or between various parts of any one wafer, or both. When any of these process deviations becomes excessive, singly or in combination, defects may appear in some features of the IC. These defects may be manifested in one of two scales: (a) as deviations of the surface appearance, observable over a considerable area and therefore with low resolution, which are usually due to slight geometric deviations (such as in the width of conductors), and (b) as more noticeable geometric distortions in minute areas, observable at full optical resolution. We shall refer to the former (those on scale “a”) as “macro-defects” and to the latter (those on scale “b”) as “micro-defects”, sometimes also as just “defects”.
Since the geometry of modern ICs is defined in units on the order of 0.1-0.2 microns, the slight deviations observable in macro-defects, while occurring over large areas, must be measured with resolutions down to the order of tens of nanometers or better, which can be done only at shorter than optical wavelengths.
Micro-defects, on the other hand, are generally (and by definition) of sizes such as to be detectable through optical microscopy. They may be due to microscopic disturbances in the process, such as dust particles, or they may be, as they often are, extreme manifestations of macro-defects.
Commonly, wafers in process are inspected periodically, e.g., after certain processing steps, in order to detect defects and to thus monitor the process.
Currently, the entire top surface of the wafer is inspected only optically and that—with special apparatus that is designed to detect micro-defects. An example of such apparatus is the Compass inspection system, sold by Applied Materials of Santa Clara, Calif.; its essential parts, notably the optical system, illustrated by the block diagram in FIG. 1 , include a light beam source, such as a laser source, optics for collimating, focusing and scanning the light beam, a wafer holder, for holding and moving the inspected wafer, at least one sensor and a processor for processing the signals from each sensor.
Detected defects are analyzed as to their number and, preferably, as to their nature. Obviously, the occurrence of a relatively large number of defects within any region, or over the entire wafer, attests to some fault or unacceptable deviation in the process and should alert the operator to try to identify the physical factor causing the deviation and to take proper remedial action, e.g., appropriately adjusting process parameters. In the case of a very large number of defects, a determination is possibly made to reject certain dies or possibly the entire wafer.
Often, detected defects are closely examined and analyzed at a separate, so-called review, phase of operation, in order to learn therefrom about the nature of the responsible process deviation or about the existence of a macro-defect and its nature, from which, again, the responsible process deviation may be deduced. Such examination is generally done at a higher resolution than that used for defects detection and may involve micro metrology techniques. It may be carried out by means of the same equipment, but often is done on a separate, very high resolution, device, such as a scanning electron microscopes (SEW—which is extremely expensive.
This current-art procedure of learning about process deviations that cause macro-defects in the fabricated ICs by detecting micro-defects, and possibly reviewing them, has two major drawbacks: Firstly and most importantly, macro-defects must be fairly severe in order for detectable resultant micro-defects to appear; there is then a risk of deleterious further deviation in the process before it is remedied; in extreme cases, the detected defects, whether micro or macro, may already be excessive, requiring wafer rejection-which obviously represents economical loss. Secondly, the close examination and analysis of defects during the review phase involves time and costly equipment; the time delay may cause additional wafers to be adversely affected before the process deviations have been identified and corrected. It is noted that the first drawback could be averted if the entire surface could be inspected at high resolution; this procedure is, however, extremely slow and, as mentioned above, requires very expensive equipment.
There is thus a clear need for a method and apparatus that would inspect the entire surface of wafers in process, directly detecting macro-defects at levels that do not necessarily result in micro-defects and thereby providing early, or more sensitive, indications of process variations. There is, moreover, a need for such process variation monitoring apparatus to be relatively inexpensive and therefore to preferably share some parts with conventional optical defects detecting apparatus.
SUMMARY OF THE INVENTION
The invention is, in essence, of a method to extend the process monitoring capabilities of a semiconductor wafer optical inspection system so as to be able to detect, and possibly quantify, macro-defects, i.e., low-resolution effects of process variations over the surface of a wafer, at much higher sensitivity than possible by analyzing micro-defects conventionally detected in such a system; optionally it enables also detecting effects of temporal process variations on successively processed wafers. The method is preferably operative simultaneously, and in conjunction, with micro-defects detection operation of such an optical inspection system and, in common with it, involves examining the entire inspectable surface of the wafer. The method of the invention is designed to detect process variations of lower magnitude than such that would result in a significant number of detectable micro-defects. It is noted that the simultaneity feature and the feature of entire surface examination, mentioned above, advantageously contrast with the mode of operation of process monitoring methods of current art, whereby geometric effects of process variations are examined only at those areas in which micro-defects have been detected and, moreover, such examination is carried out at a so-called review phase, which is separate from the defects detection operation and during which a higher-resolution scan is required—possibly even using different equipment.
In one embodiment of the invented system, partial results of the defects detection operation are further processed to directly obtain indications of process variations over the entire inspected area. Also in common with the defects detection operation, the invented method can advantageously use the outputs of any multiple sensors comprised in the inspection system, such as those disposed along various angles to the inspected surface and to the illuminating beam, including sensing a so-called dark field or a so-called bright field, to sense more varied effects and thus obtain more accurate or more reliable results. The invented method can also form a basis for a capability of classifying process variations whose effects have been detected and measured by it, although the embodiments to be described below do not include such a capability.
Optionally and with obvious modifications, the invented method can function separately from, or independently of, defects detection operation, although, it is noted, combined operation is generally more economical. The invention is also of equipment and system operative to carry out the method as disclosed herein.
It will be appreciated that, though the present disclosure describes the invention in terms of inspecting semiconductor wafers, being processed to become integrated-circuit dies, the invention is equally applicable to the inspection of surfaces of other substrates, such as those carrying photonic devices or those undergoing any other processing, as well as surface variations not necessarily ascribable to a process. It will be appreciated that the invention is equally applicable to the inspection of surfaces by means other than optical, such as an electron-or ion beam, and, in general, to any inspection system whereby the surface is probed or sensed point-by-point. In any such system each sensor outputs intensity values that correspond to energy received by the sensor as a result of reflection of the probing beam from the inspected surface. These values are generally called radiation intensity values, but in the sequel will also be referred to, interchangeably, as light intensity values (since the preferred embodiments utilize a light beam for the probing).
The invented method, as applicable to a wafers inspection system, basically comprises the following logical steps: (a) Obtaining one or more light intensity values for each point (pixel) on the inspected surface, belonging to corresponding classes, such as the outputs of the various sensors in the inspection system; these may be identical to the values used for micro-defects detection; (b) preferably calculating for each pixel one or more derived values; (c) dividing the surface into an array of geometric blocks, each block including a considerable plurality of contiguous pixels; (d) calculating for each block, as a whole, a so-called signature, which is a set or an array of variables, as a function of the light intensity values and the derived values of its several pixels; (e) for each block, comparing its signature with a designated comparison signature, possibly associated with a comparison block, and thereby calculating one or more process deviation indications.
The derived values in step b are preferably local spread values, i.e. a measure of the extent of variability of intensity values in the immediate vicinity of the referenced pixel; they are calculated separately with respect to each class (i.e., sensor).
In one embodiment of the method, calculating a signature includes calculating for each pixel, and, a with respect to each class, a histogram over pairs of light intensity-and spread values. In one configuration, there is provided for each block over the surface of the wafer a model comparison signature and the comparing in step e is with respect to that model signature. In another configuration, the comparison with respect to any block, is between any signature calculated for the currently inspected wafer and a corresponding one calculated for the previously inspected one. In yet another configuration, applicable to the prevalent case that the IC being fabricated is an array of identical dies, the array of blocks is defined in alignment with the array of dies, there being a plurality of blocks over each die; the comparing of signatures is between any block and a congruent block over one or more other dies.
In another embodiment of the invented method, applicable particularly when also micro-defects are being detected, there are first obtained for each pixel, and corresponding to each sensor, a light intensity value and possibly a local spread value-both in comparison with corresponding ones for a congruent pixel on another die. The differences yielded by such comparisons are preferably thresholded according to a given threshold curve and each excess is noted; the threshold values of the given curve are typically much lower than those applied in a similar procedure during detection of defects. Finally, the excesses, corresponding to each sensor, are counted over each block, the sums forming the respective process deviation indications.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to understand the invention and to see how it may be carried out in practice, a preferred embodiment will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:
FIG. 1 is a schematic diagram of a wafer inspection system used in an embodiment of the invention.
FIG. 2 is a schematic diagram of the surface of a wafer, showing the relationship between pixels, blocks and dies according to the invention.
FIG. 3 is a diagram showing a typical block histogram, used in an embodiment of the invention.
FIG. 4 is a diagram showing a typical normal distribution of pixel values and typical threshold curves used for defects detection, according to prior art, and for process deviation measurement according to a second configuration of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The method of the invention is preferably embodied as an additional computer program, runable on a digital processor resident in a wafer inspection system, which normally serves to detect defects after certain wafer processing stages. A particular example of such an inspection system, which will be used herein to illustrate the method, is the Compass inspection system, sold by Applied Materials of Santa Clara Calif., mentioned in the Background section above and shown schematically in FIG. 1 . It should however be understood that the method of the invention can also be embodied, with obvious modifications, as an appropriate program on any processor in other inspection systems, including those that serve to inspect surfaces other than semiconductor wafers. It should likewise be understood that the method of the invention can also be embodied, with obvious modifications, in a system specifically or solely designed for it, for the purpose of process variation monitoring only.
In the inspection system 30 of FIG. 1 , a light source 31 , preferably a laser, and an optical system 33 project a focused light spot normally onto the surface of a wafer 36 . The wafer is moved by a scanning mechanism 34 so as to be scanned by the focused spot in a regular raster of parallel lines. Light reflected or scattered from the surface into various directions is collected by sensors 35 and is converted to corresponding electrical signals; these are sampled at regular intervals and digitized, to produce corresponding light intensity values-to be hence referred to as intensities. The intensities are fed to processor 32 , which is usually programmed to perform analysis of the signals so as to determine defects, but preferably is also programmed to perform the analysis according to the method disclosed herein. The position of the beam on the surface that corresponds to any one sampling is known as a respective pixel. The distance between the scan lines determines the distance between adjacent pixels along one axis and the ratio between the sampling rate and the scanning speed determines the distance between adjacent pixels along the orthogonal axis. Typically, this distance, along each axis is between 0.5 and 2 micrometers. Preferably one sensor collects light reflected normally and is referred to as bright-field sensor, four sensors collect light reflected at a large angle to the normal (at corresponding four azimuth directions) and are referred to as dark-field sensors, and one ring-shaped sensor collects light reflected at a small-to-medium angle to the normal and is referred to as gray-field sensor. The same descriptors apply also to the corresponding digital intensity values; more generally, however, the intensities from the various sensors may be regarded as belonging to corresponding different classes and will be referred to as such in the sequel.
Different classes of light intensities may also be associated with other parameters affecting the scanning and the sensing of reflected light, such as spectral differences.
In most fabrication situations, a semiconductor wafer is processed to produce a regular array of identical circuit patterns, to become dies (also known as chips), as illustrated in FIG. 2 , which schematically shows die areas 22 in relation to a wafer 20 . Accordingly, defects 26 are usually detected by comparing values obtained from each die 22 with those obtained from one or more other dies 22 on the wafer or, alternatively, from a model (“golden”) die.
More specifically, the following procedure is typically carried out for each pixel and for each class of intensity values (of the six classes associated with the six sensors): The intensities of the pixel and of a group of neighboring pixels (e.g. the immediately adjacent pixels) are mutually compared, to yield corresponding spread values S. A particular comparison function is, for example, finding the highest-and the lowest intensity values and calculating the absolute difference between them.
The six intensity values I and the six corresponding spread values S are compared with those of a pixel at an identical position with respect to another die. Preferably the other die is the one just previously scanned by the laser beam, but it may be another one on the wafer, or a model die. The resultant array of 24 numbers (I and S values from each of the two dies for each of the six classes) is analyzed, applying suitable algorithms and parameters, to determine whether the pixel is defective. In general, such algorithms and parameters includes classifying the circuit pattern in which the pixel is located, on the basis of known combinations of ranges of the I and S values, and defining deviation thresholds, i. e. maximum acceptable deviations, for the various values for each class of pattern. When the difference between the two dies, with respect to one or several sensed values, exceeds the pertinent deviation threshold, the pixel is suspect of being defective. A pixel that is thus suspect, on the basis of comparison with two other dies, or with a model die, is determined to be defective. It is again noted that the number of sensors and corresponding intensity values per pixel need not be six, as in this exemplary system, but may be any number, including one.
According to an embodiment of the present invention, the array of pixels over the surface of the wafer is logically divided into contiguous rectangular blocks, each containing an array of, typically, 500×100 pixels. The blocks, in turn, form a Cartesian array. Preferably the array of blocks is aligned with the array of dies, so that all dies are identically divided into blocks. The relation between them is shown in FIG. 2 , where each die 22 is seen to be identically divided into a number of blocks 24 (only few of which are shown in the drawing). If the pixels are spaced 2 micrometers, the size of a block 24 would typically be 1×1 millimeter and a typical die, of gross size 10 millimeter, would contain 10×10 blocks.
Now, for each block and for each class (i.e., sensor) there is preferably computed a histogram of the number of pixels sharing any pair of values I and S. The histogram, to be referred to as Block Characteristic Histogram (BCH), may be visualized as a two-dimensional array, one axis representing 256 values of I and the other 256 values of S (assuming that each value is represented by an 8-bits number). It is noted that a typical distribution of values in a BCH depends on the type of the circuitry underlying the particular block, as well as on the class of I values. For example, in the BCH that corresponds to a Dark-Field sensor there will typically be a predominance of medium intensity values and medium spread values for a memory circuit region, characterized by a uniform pattern, while for a bare silicon (sparse circuitry) both intensity and spread values are predominantly low. A typical histogram for a bright-field sensor and a memory region is shown schematically in FIG. 3 , where, for the sake of clarity and simplicity, the number of values of I and of S are only 16 each. It would be appreciated that the two variables underlying the histogram need not be I and S, but may be any other values derived from the light intensities.
The set of BCHs (six in this exemplary preferred embodiment) is a particular type of a so-called signature of the block. Other types of signatures are possible within the present invention and are calculable for each block, either from its BCHs or directly from its intensities and any derived variables (such as the spread values). One simple example of such a signature is a set of any of the averages of the values (e.g., I or S or both) for each class over the block. As another example of signature calculation, all the intensities for which the respective spread value is under a certain threshold (signifying sparse circuit region) are averaged.
An example of a function computable for each class, either directly or from a respective BCH, to produce a block signature, is the correlation between spread and intensity values. Other types of block signatures may include, for example, functions of the plurality of BCHs related to the block.
There will thus be created a signature for each block over the surface of the wafer. It is noted that, with some types of signatures, the parameters governing their calculation may vary from block to block-to suit various types of underlying patterns (i. e. various types of circuitry). Next, for each block at a time, to be referred to as a current block, its signature, to be referred to as a current signature, is compared with a so-called comparison signature, to yield a set of one or more so-called process variation indications for the block. Any such comparison is preferably governed by one or more parameters-usually defining ranges of allowable deviations; these are determined, again, preferably as a function of the underlying circuitry patterns. The collection of all such comparison parameters, as well as the above-mentioned parameters governing the formation of signatures, over the area of the wafer or of any one die, form together a parameters map of the wafer or the die; such a map is determined once for each type of die whose processing is being monitored.
Several configurations of the preferred embodiment of the invention, differentiated by the source of the comparison signature, are contemplated.
According to a first configuration, serving for absolute process variation detection, there is preliminarily defined a model signatures map-over the entire surface of the wafer, or over the area of a single die (assuming a pattern of identical dies over the wafer). Such a map is preferably produced for each type of a die (i.e., circuit pattern) or each batch of production and may be generated, for example, by subjecting one or more samples known to be perfect to the above-described scanning and signature computation process. During inspection, the signature for each block is compared with the corresponding one in the model map. According to a second configuration of this embodiment, serving for inter-wafer process variation detection, the signature for each block is compared, during inspection, with the corresponding one in a previously inspected wafer, preferably the immediately preceding one. A third configuration, serving for die process variation detection and applicable to the case of a pattern of identical dies over the wafer, is similar to the second configuration, except that during inspection, the signature for each block is compared with that of a corresponding block in one or more other dies, preferably-adjacent dies. This configuration may be applied more generally for any surface on which there are repetitive identical instances of any given pattern on the surface being inspected.
As discussed above, each comparison process is governed by comparison parameters taken from the parameters map (which generally vary among the blocks). A typical example of a comparison process, applicable to the case that a signature is a single number, possibly one per class, is simply computing the absolute difference between the corresponding numbers in the current signature and the comparison signature and determining whether any computed difference exceeds a corresponding threshold in the parameters map; if it does, a suitable process variation indication is assigned to the current block.
Another example of a comparison process, applicable to the case that a signature is a BCH of I and S values, is as follows: For each class, an average absolute difference value is computed, by absolutely subtracting, for each pair of I and S values, corresponding entries in the current BCH and the comparison BCH from each other and averaging the results. The maximum average difference from among all classes is then compared with a corresponding threshold in the parameters map, to possibly yield an indicative process variation value. According to a modification of the latter exemplary method there is defined in the parameters map, for each class and each block, a set of deviation thresholds as a function of I and S values; the differences between entries in the current BCH and the comparison BCH are compared with corresponding deviation thresholds and any excess yields a deviation flag; the existence of a deviation flag from any of the class-related BCHs associated with the block, and possibly the number of such flags, is indicative of the occurrence of any process variation, possibly—of its magnitude.
It is noted that the pixel light intensity values, used by the method, and possibly also the spread values, are essentially the same used for defects detection, if the system also serves for that. Sharing of the system, in this way, by the defects detection process and by the process variation monitoring of the present invention is thus extremely economical. Moreover, the two procedures may be simultaneous, thus saving time. Nevertheless, the method of the invention may also be implemented in a stand-alone system, essentially as described hereabove.
Another embodiment of the invention, which is particularly adapted to serve cooperatively with a defects detection system, is as follows: The intensities sensed at each pixel and, possibly, the derived spreads are compared with those of a corresponding pixel on another die, to be referred to as a comparison die, in a manner similar to that employed in defects detection. However, the threshold of deviation is in this case set at considerably lower levels than for defects detection.
Thus generally, a much larger number of pixels will have intensity and spread values that unacceptably deviate from the comparison values. These are marked as abnormal pixels. As in the first preferred embodiment, the area of the wafer, and of each die, is logically divided into blocks. The number of abnormal pixels in each block is counted and blocks with high count are reported as exhibiting a process deviation. Again, the procedure is carried out with respect to each class (e.g., sensor). The process may be illustrated by a comparison histogram, a simplified example of which (typical for a certain circuit region) is shown schematically in FIG. 4 , where the two axes represent values of intensity in the first and second die, respectively. For each combination of intensity values, the number of pixels within a block, for which that combination occurs, is recorded. Ideally, all entries would be along a certain section of the main diagonal, but, owing to process “noise” and variations, there actually are many pixels with unequal values in the two dies. In FIG. 4 there are drawn typical contour lines 45 that delineate distribution levels of value pairs, the innermost contour, for example, including 90 percent of all pixels sensed. Two pairs of threshold lines, approximately parallel to the main diagonal, are drawn at some chosen relation to the contours 45 ; in effect, they divide the histogram area into five regions. A first pair of lines 41 , farther from the diagonal, serves to distinguish defective pixels 43 , while a second pair of lines 42 , closer to the diagonal, serves to distinguish abnormal pixels 44 . It is noted that lines 41 are those used in a prior art inspection system, such as the aforementioned Compass system, to distinguish defects and may optionally be used also in the system of the invention; however, lines 42 and their use to distinguish abnormal pixels are a novel feature of the invention. In any case, all pixels with values outside lines 42 (including those possibly outside lines 41 ) are preferably counted as abnormal.
It is possible to devise also formulas that consider the counts of abnormal pixels corresponding to various sensors differentially, or in a weighted sum manner, and to thus gain additional information about the process variation being monitored; all these will be generally referred to as calculating a relationship between the pixel abnormality indications. In another configuration of this embodiment, the comparison values are taken from a model die and may be stored; more generally, the comparison values may be regarded as forming a suitable comparison array of values (which is derived either from the comparison die or from the model die).
When applying any of the methods of the invention within a process variation monitoring system (which may be part of a wafer inspection system), deviations, which are reported block-by-block as described above, may be presented graphically to the fabrication process operator, for him to deduce the process variation that may have caused them. Alternatively, the reported data may be automatically applied to an interpretation process, which will output information about the possible process variations or the data may be otherwise processed.
Another alternative is to initiate review type inspection (e.g., high resolution observation) with respect to reported blocks, possibly certain blocks with particularly high deviation scores. It is noted that these reviewable locations will, in general, be additional to those indicated by defects (detected by current methods), though some of the locations may be approximately identical. It is further noted that the manner of applying results of the method to process monitoring, as discussed for example in the present paragraph, are outside the scope of the invention and are mentioned by way of illustrating its utility.
It would be appreciated that many variations of the methods described hereabove, including various other configurations and functions, as well as applications to other types of surfaces, patterns and processes, are possible-all coming within the scope of the invention, which is solely defined by the following claims.
It will also be understood that the system according to the invention may be a suitably programmed computer or digital processor. Likewise, the invention contemplates a computer program being readable by a computer for executing the method of the invention. The invention further contemplates a machine-readable memory tangibly embodying a program of instructions executable by a machine for executing the method of the invention.
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A method to extend the process monitoring capabilities of a semiconductor wafer optical inspection system so as to be able to detect low-resolution effects of process variations over the surface of a wafer at much higher sensitivity than heretofore possible. The method consists, in essence, of grouping sensed pixels by geometric blocks over the inspected surface and comparing each block with a corresponding one from another die on the same wager, from another wager of from a stored model image. In one embodiment of the invention, pixel values are compared directly and differences are thresholded at a considerably lower level than during a defects detection process. In another embodiment, there is calculated a signature for each block, based on the sensed light intensity values, and corresponding signatures are compared.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the priority of German Patent Application, Serial No. 103 16 244.5, filed Apr. 9, 2003, pursuant to 35 U.S.C. 119(a)-(d), the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a spindle unit for machine tools that facilitates an automatic tool change, as well as to a corresponding method for operating such spindle unit.
[0003] Motor-driven milling spindles typically include a shaft with a shrink-fit rotor arranged between two bearings assemblies. A tool tensioning system consisting of a chucking head, tie rod and typically a disk spring arrangement is arranged in the interior of the shaft. Frequently, a tensioning system sensor located on the tie rod and a tool loosening rod are typically attached to the end of the spindle unit. Optionally, a rotary feedthrough that is supported in roller bearings can be coupled by way of a connecting piece.
[0004] This type of spindle with a tool chuck is disclosed in the German patent publication DE 199 37 447. A tie rod that can rotate and axially move with the spindle is arranged in the spindle for clamping and/or loosening the tool chuck. At least one contactless operating sensor is provided for measuring the positions of the tool chuck. A sensor that measures continues the displacement of the tie rod is provided to better control clamping of the tool.
[0005] The German patent publication DE 36 29 453 describes an electromechanical device for generating an axial force for operating collets. An electric motor moves a hollow tie rod via a spur gear and a spindle drive in an axial direction. To reduce the friction forces caused by operating in a relatively small installation space, the rotor is connected with a pinion which engages with a toothed gear that is secured on an spindle that is supported in a housing and is prevented from moving in an axial direction. A spindle nut, which is connected to the tie rod that is supported in the housing for axial movement relative to the housing, is arranged on the spindle. Consequently, a separate electric motor has to be used for moving the tie rod.
[0006] It may sometimes be desirable to separate an entire spindle unit into a drive unit and a coupled anterior spindle, for example for exchanging or automatically changing the anterior spindle, for being able to use larger or smaller tools, or for intermediately connecting a two-stage planetary drive to increase the torque.
[0007] With conventional spindles, the tie rod, which has to remain in the anterior spindle, disadvantageously has to extend through the coupling and the motor shaft so as to reach the tool changing assembly and the tie rod sensor located behind the motor. This can not only result in a complex configuration due to the limited space reasons, but can also cause dynamical problems associated with oscillations. When the anterior spindle is changed, Moreover, the area behind the drive motor would need tom be accessed when mounting/exchanging a tool, which would negate any advantages achieved by separating these components.
[0008] It would therefore be desirable and advantageous to provide an improved spindle arrangement for machine tools and a corresponding method for operating such spindle arrangement, which obviates prior art shortcomings and is able to specifically facilitate automatic tool changes.
SUMMARY OF THE INVENTION
[0009] According to one aspect of the present invention, a spindle unit for a machine tool includes a drive unit having a drive shaft, a spindle head assembly constructed for receiving a tool and having a hollow spindle head shaft driven by the drive unit, a tie rod arranged for axial displacement in the hollow spindle head shaft and mechanically coupled with the drive shaft, and a shifting unit for axially moving the drive shaft together with the tie rod.
[0010] According to another aspect of the invention, a method for operating a spindle unit for a machine tool of a type having a drive unit with a drive shaft and a spindle head assembly for receiving a tool with a tie rod, includes the steps of shifting the tie rod in axial direction to a first position with the help of the drive shaft, and moving the drive shaft backwards in axial direction to a second position, thereby also enabling a backward movement by the tie rod.
[0011] According to another feature of the present invention, the spindle head assembly and the drive unit can be detachably connected to one another. As a consequence, also the drive shaft and the tie rod can be detachably connected.
[0012] According to another feature of the present invention, the spindle head shaft may have one end facing the drive shaft and may be constructed as a spline shaft, with the drive shaft having an end face constructed as a hollow wheel to complement the one end of the spindle head shaft and to enable coupling therewith, or vice versa.
[0013] If the spindle head is arranged removable from the drive unit, then the drive shaft can have a central bore for transporting a material, and a removable tube of the tie rod can extend into the central bore. Alternatively, the tie rod can have a central bore for transporting a material, and a removable tube of the drive shaft can extend into the central bore. This arrangement can be used, for example, to feed a lubricant through the drive shaft to the tool.
[0014] The drive shaft can be formed in one piece with the tie rod. The tie rod and the spindle head shaft can then have mating interlocking teeth or wedges for transferring the torque from the drive shaft to the spindle head shaft.
[0015] The drive unit can also include an electric motor with a rotor mounted on the drive shaft. Because the drive shaft is moveable, the dimensions of the stator of the electric motor should be selected so as to completely surround the rotor independent of the displacement of the shifting unit. The electric motor can then operate with maximum efficiency at any displacement position.
[0016] According to another feature of the present invention, the spindle unit may include an axially displaceable bearing assembly, for example, bearing sleeves, for support of the drive shaft. The present invention is based on the premise to configure the bearings sleeves of the drive motor to be movable between two stops, for example by a hydraulic mechanism, because the bearings sleeves are typically hydraulically pretensioned in the axial direction to compensate for thermal effects. The drive shaft can also be moved hydraulically because, as described above, a hydraulic unit is frequently already installed for the purpose of pretensioning the bearing sleeves. Other mechanisms, such as pneumatic and/or electromechanical mechanisms, can also be used to move the drive shaft. During the operation, the tie rod can be moved so as to contact the drive shaft. A sensing device can be added for measuring an axial position of the drive shaft and to thereby indirectly measure also the axial position of the tie rod. This has the advantage that the position of the tie rod is known when the position of the drive shaft is known.
BRIEF DESCRIPTION OF THE DRAWING
[0017] 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 the sole FIGURE shows a cross-sectional view of a motor-driven milling spindle according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] The depicted embodiment is 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.
[0019] This is one of two applications both filed on the same day. Both applications deal with related inventions. They are commonly owned and have the same inventive entity. Both applications are unique, but incorporate the other by reference. Accordingly, the following U.S. patent application is hereby expressly incorporated by reference: “SPINDLE UNIT WITH SWITCHABLE GEAR, AND METHOD FOR USING THE SPINDLE UNIT”.
[0020] Turning now to the FIGURE, there is shown a cross-sectional view of a separable motor-driven milling spindle according to the present invention including a housing 1 for accommodation of a drive unit 2 and a spindle head assembly or anterior spindle 3 . The drive unit 2 basically includes an electric motor with a stator 4 and a rotor 5 which is shrink-fit on a drive shaft 6 . The drive shaft 6 is supported on both ends by bearing sleeves 7 , 8 . The bearing sleeves 7 , 8 can be moved in the axial direction with a hydraulic system (not shown). In the example depicted in the FIGURE, a piston space 9 is pressurized, allowing the bearing sleeve 8 with the drive shaft and the bearing sleeve 7 to move in a direction away from the anterior spindle 3 . A second piston space 10 is provided on the bearing sleeve 7 that faces the anterior spindle. When the second piston space 10 is pressurized, the bearing sleeve 7 with the drive shaft 6 and the bearing sleeve 8 move toward the anterior spindle 3 .
[0021] The anterior spindle 3 basically includes a spindle head shaft 11 and a tie rod 12 capable of actuating a collet 13 for clamping tools. The tie rod 12 and the collet 13 are shown in the FIGURE in two different positions. In the upper section of the FIGURE, the tie rod 12 and the collet 13 are in a forward position adapted to eject a tool. In the lower section of the FIGURE, the tie rod 12 and the collet 13 are in a retracted position, in which the tool is clamped. The axial pressure of the drive shaft 6 is provided via a tubular extension 14 of the drive shaft that presses against a corresponding shoulder 15 of the tie rod 12 .
[0022] Torque is transferred from the drive shaft 6 to the spindle head shaft 11 via a coupling that includes a spline-shaped end 16 of the spindle head shaft 11 and a mating hollow wheel 17 which is non-rotatably connected with the drive shaft 6 . The hollow wheel 17 is axially movably and engages non-rotatably with the spline-shaped end 16 .
[0023] A position sensor 18 is provided to measure the axial position of the tie rod 12 and to transmit a corresponding position signal to a control circuit (not shown) of the motor-driven milling spindle.
[0024] A rotary encoder 19 that is axially moveable with a shaft 6 is arranged on the end of the drive shaft 6 that faces away from the anterior spindle 3 . The rotary encoder 19 measures the rotation speed and rotation position, respectively, of the drive shaft 6 . Because the drive shaft 6 is non-rotatably coupled to the spindle head shaft 11 , the rotation speed and rotation position, respectively, of the spindle head shaft 11 can likewise be measured.
[0025] The drive shaft 6 has a central bore through which lubricants can be supplied to the tool. Since the spindle head 3 is configured to be removable from the drive unit 2 , the tie rod 11 has a tubular extension 21 that faces the drive unit 2 and extends into the bore 20 . The tie rod 12 also has a bore for supplying the lubricant. This bore is only partially indicated in the FIGURE. To facilitate insertion of the tubular extension 21 into the bore 20 , the drive shaft 6 has a funnel-shaped receptacle 22 on the side facing the tie rod.
[0026] The force required to eject a tool is produced by the pretensioning pressure of the bearing sleeves via the bearings. The ejection forces are typically small enough so as not to damage the bearings. The length of the coupling located between the drive shaft 6 and the spindle head shaft 11 , including the spline-shaped end 16 of the spindle head shaft 11 and a hollow wheel 17 , has to allow a sufficiently long stroke for ejecting the tool. The various pressures of the hydraulic system are adjusted so that the drive shaft 6 remains in contact with the tie rod 12 in the axial direction during operation of the spindle unit. Because the drive shaft 6 can be regarded as an extension of the tie rod, its position can also be measured. Alternatively, is indicated above, the drive shaft 6 can also be formed as one piece with the tie rod 12 , so that the position of the tie rod can also be inferred from the position of the drive shaft.
[0027] The lubricant is introduced into the drive shaft through a rotary feed 27 disposed on an end of the drive shaft 6 that faces away from the anterior spindle 3 . The rotary feed 23 does not have to be separately supported since it is mounted on the drive shaft 6 and is hence supported by the drive shaft 6 .
[0028] This design permits a tool change while the spindle unit is rotating, because unlike with conventional spindles, there is no need for a rod to exert pressure on to the stationery tie rod. Accordingly, there is also no need for a safety device that would force the spindle to a stop during a tool change.
[0029] 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.
[0030] 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 spindle unit for a machine tool includes a drive unit having a drive shaft and a spindle head assembly constructed for receiving a tool and having a hollow spindle head shaft driven by the drive unit. Arranged for axial displacement in the hollow spindle head shaft is a tie rod which is mechanically coupled with the drive shaft so as to transmit an axial movement of the drive shaft to the tie rod.
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This application is a division of application Ser. No. 08/132,246, filed Oct. 6, 1993 now U.S. Pat. No. 5,442,038.
FIELD OF THE INVENTION
This invention relates to polymers of maleic acid and amines.
DESCRIPTION OF RELATED ART
It is well known that polymers of ammonia and maleic acid can be prepared by thermal condensation of one or more equivalents of ammonia with maleic acid, malic acid, fumaric acid or the mono- or diamides of maleic acid, malic acid or fumaric acid.
U.S. Pat. No. 4,839,461 discloses a method for making polyaspartic acid from maleic acid and ammonia by reacting these constituents in a 1:1-1.5 molar ratio by raising the temperature to 120°-140° C. over a period of 4-6 hours and maintaining it for 0-2 hours.
Dessaigne (Comp. rend. 31, 432-434 [1850]) prepared condensation products which gave aspartic acid on treatment with nitric or hydrochloric acid by dry distillation of the acid ammonium salts of malic fumaric or maleic acid at unspecified times and temperatures.
U.S. Pat. No. 3,846,380 discloses that polysuccinimide may be made by heat condensation of the following starting materials, aspartic acid; ammonium salts of aspartic acid, malic acid, maleic acid and fumaric acid; and mono- and diamides of aspartic acid, malic acid, maleic acid and fumaric acid.
U.S. Pat. No. 4,696,981 discloses the formation of anhydropolysuccinic acid by the microwave radiation of ammonium salts of malic acid via the formation of ammonium maleate.
Jpn. Kokai 60,203,636 [C.A. 104, 207690m, 1986] discloses a method for the synthesis of copolymers of aspartic acid by heating amides, ammonium salts or monoamide-ammonium salts of malic acid, maleic acid or/and fumaric acid with one or more amino acids at 180° C. for four hours.
A method of preparation of polyaspartate, useful for inhibition of incrustations due to materials causing hardness in water and of value in detergent formulations, in which maleic acid or fumaric acid are reacted in a molar ratio of 1:1-2.1 at temperatures greater than 190° C., followed by conversion of the polymer formed in this reaction to a salt of polyaspartic acid by basic hydrolysis is disclosed by U.S. patent application Ser. No. 08/007,376, filed May 14, 1992, by Louis L. Wood.
A method for obtaining higher molecular weight copolymers of polyaspartic acid, suitable for the inhibition of scale deposition, by reacting maleic acid and ammonia in a stoichiometric excess, with a diamine or a triamine, at 120°-350° C., preferably 180°-300° C., and then converting the copolymer of polysuccinimide formed to a salt of a copolymer of polyaspartic acid by hydrolysis with a hydroxide is disclosed in U.S. patent application Ser. No. 07/968,506, filed Oct. 10, 1992 by Louis L. Wood.
Copolymers of polyamino acids formed by reaction of polysuccinimide with alkyl, alkenyl, aromatic amines or alkyl and alkenyl polyamines are useful as inhibitors of mineral scale deposition are disclosed in U.S. patent application Ser. No. 07/968,319, filed Oct. 29, 1992 by Louis L. Wood and Gary J. Calton.
U.S. patent application Ser. No. 07/994,922, filed Dec. 22, 1992, by Louis L. Wood and Gary J. Calton, discloses copolymers of polyaspartic acid which are suitable for the inhibition of scale deposition which are obtained by reacting maleic acid, an additional polycarboxylic acid and ammonia in a stoichiometric excess, at 120°-350° C., preferably 180°-300° C., to provide copolymers of polysuccinimide. In a second embodiment, a polyamine was added to the reaction mix. These intermediate polysuccinimide copolymers could then be converted to the salts of copolymers of polyaspartic acid by hydrolysis with a hydroxide.
U.S. patent application Ser. No. 08/031,856, filed Mar. 16, 1993 by Louis L. Wood, discloses a method for preparing copolymers of polyamino acids by reaction of an alcohol with maleic anhydride to form the half ester followed by addition of ammonia, ammonia and an amine, or ammonia and a polyamine. The mixture is then heated to 120°-350° C. to form polysucclnimide or a derivative thereof. The resulting polysuccinimide may be hydrolyzed to form its salt or reacted further to provide a derivative of polyaspartic acid.
It is also well known that maleic polymers can be obtained through radical polymerization as disclosed in U.S. Pat. No. 5,064,563 and references cited therein.
SUMMARY OF THE INVENTION
We have found that useful polymers and salts thereof can be prepared by thermal condensation, at temperatures above 120° C., but preferably above 160° C. and more preferably above 190° C. for a time sufficient to remove the water of condensation, of less than one equivalent of an amine having the formula NHR'R" where R' and R" can be the same or different and where R' and R" independently represent hydrogen or an alkyl, a carboxy alkyl, an hydroxyalkyl, an alkenyl, an alkyl amine, or an alkyloxy amine, with a monomer selected from the group of monomers consisting of maleic acid, malic acid, fumaric acid or maleic anhydride. Such polymers are easily formed when the amine is present at 0.05 equivalent of amine per mole of monomer to less than 1 equivalent of amine per mole of monomer. A preferred range of amine is 0.25 to less than 1 equivalent of amine per mole of monomer. An especially preferred range of amine is 0.5 to less than 1 equivalent of amine per mole of monomer. Amines such as ammonia or those having at least one primary or secondary amine are useful in formation of the polymers. Molecules having additional amine groups consisting of at least one or more primary or secondary amines are of value in extending the molecular weight of the polymer. Illustrative of the types of amines which might be used are alkyl amines having 1-36 carbons, polyoxyalkyleneamines, polyoxyalkylenediamines, polyoxyalkylenetriamines, alkyl diamines such as ethylene diamine or hexanediamine, alkyltriamines such as diethylene triamine or melamine, or amino acids such as lysine and arginine. Permutations and combinations of the various amines provide polymers, all of which have useful properties, to a greater or lesser degree, as described below. The process for synthesis of the polymers comprises polymerizing (1) one of the members of the group consisting of maleic acid, maleic acid, and fumario acid and (2) less than one equivalent of ammonia, at a temperature greater than about 120° C., to produce said polymer; polymerizing (1) one of the members of the group consisting of maleic acid, malic acid, and fumaric acid, (2) less than one equivalent of ammonia and (3) an amine, at a temperature greater than about 120° C., to produce said polymer; polymerizing (1) one of the members of the group consisting of maleic acid, malic acid, and fumaric acid, (2) less than one equivalent of ammonia, and (3) a carboxylic acid, at a temperature greater than about 120° C., to produce said polymer; or polymerizing (1) one of the members of the group consisting of maleic acid, malic acid, and fumaric acid, (2) less than one equivalent of ammonia, (3) an amine and (4) a carboxylic acid, at a temperature greater than about 1200° C., to produce said polymer. The polymer may be hydrolyzed to form a salt having high carboxyl functionality by further reacting said polymer with a salt of an alkali, an alkaline earth metal or ammonia which is capable of hydrolyzing said polymer. Among those salts capable are the oxides, carbonates or other weak acid salts, such as those of organic acids, and hydroxides of the alkali or alkaline earth elements, or ammonium hydroxide. Each of these hydrolysates provides a salt of the polymer wherein the counter-ion of the salt Is an ion of an alkali, an alkaline earth metal or ammonia. Other carboxylic acids may be incorporated providing a variation in the hydrophobic/hydrophilic ratio and varying the interatomic distance between carboxylic acid functionalities. Illustrative examples of such acids are monocarboxylic acids such as alkyl carboxylic acids containing 1-36 carbons, for example stearic, oleic, N-methyl-N-lauric, and palmitic acids, amino acids such as alanine, lysine and polycarboxylic acids such as adipic acid, citric acid, fumaric acid, malic acid, malonic acid, succinic acid, glutaric acid, oxalic acid, pimelic acid, itaconic acid, nonanedioic acid, dodecanedioic acid, octanedioic acid, isophthalic acid, terphthalic acid, phthalic acid or polycarboxylic acids, such as aspartic acid or glutamic acid. The molecular weight of these polymers, with or without the inclusion of alternate carboxylic acids, may be extended by substituting a polyamine for a portion of the ammonia used.
The polymer formed may then be hydrolyzed to give a water soluble polycarboxylic acid salt. The alkaline hydrolysis is carried out for a suitable time at a temperature in the range of 0° to 50° C., and if necessary, with cooling. The reaction is generally complete after several minutes, but it may take several hours, in some cases, before it goes to completion. The alkali hydroxides or carbonates of alkali metals and alkaline earth metals, for example, NaOH, KOH, LiOH, RbOH, CsOH, Li 2 CO 3 , Na 2 CO 3 , Rb 2 CO 3 , Cs 2 CO 3 , Ba(OH) 2 , etc., may be employed as well as the salts of the alkali or alkaline earth metals with a weak Lewis acid, where the pH of the salt in aqueous solution is above 5.5. Illustrative examples of these salts are the sodium salts of carbonic acid, acetic acid, formic acid and the like. The concentration of alkali employed can be varied widely depending upon the number of hydrophobic groups in the material to be hydrolyzed, but the preferred concentration is in the range of 0.1 to 10 N. The hydrolysis product may provide both alpha and beta carboxyl groups to the amines. This ratio may vary due to the strength of the hydrolyzing agent; however all of the hydrolyzing agents tested have given excellent activities in the testing carried out.
At the present time, the structure of the polymers is unknown, and although not wishing to be held to any theory, the lack of an equivalent amount of an amine in the reaction with maleic acid would appear to preclude the formation of a strict polyamlde, as has been suggested to occur by a number of authors concerning the thermal polymerization of maleic acid with more than one equivalent of an amine. Studies of the mechanism of the anionic polymerization of maleic anhydride catalyzed by triphenyl phosphine and tributyl phosphine, showed the formation of succinic anhydride units and cyclopentanone units or ketoolefinic units. Such units, along with their nitrogen containing analogs may well present in the polymer of the present invention, most probably randomly interspersed in the polymer chain.
The polymers of the present invention provide properties which are different from their counterparts prepared with one or more equivalents of amine. The polymers also provide materials which are distinctly advantageous in their lighter color. The economic advantage due to reduced quantities of ammonia provides an economic incentive for their use.
The polymers are valuable intermediates which may be reacted further, for instance, after the manner of Jacquest, et al, U.S. Pat. No. 4,363,797, Fujimoto et al, U.S. Pat. No. 3,846,380 or Wood, U.S. patent application Ser. No.08/031,856 filed Oct. 6, 1993, issued as U.S. Pat. No. 5,442,038 on Aug. 15, 1995.
The salts of these polymers are valuable as solubilizing agents, dispersing agents, emulsifying agents, rust-proofing agents, fiber-treating agents, level dyeing agents and retarding agents, inhibitors of metal scale deposition and inhibitors of corrosion of ferrous metals. As dispersing agents, they are useful in suspending paints, coal, clay, pigments and paper fibers, to provide even suspensions, pumpable fluids and to prevent settling of sediments, for instance. The inhibition of metal scale deposition by these polymer salts may occur by prevention of nucleation of salts such as those of calcium, strontium, barium and magnesium in waters as well as by prevention of crystal growth by the addition effective amount of a the salt of the polymers. The use of said polymer salts in water treatment may also be desirable as a result of disruption of the crystal pattern of the metal salt, making a scale which is more easily removed. Thus, the incorporation of these salts or polymers into water treatment composition, which include a scale deposition inhibition effective amount of the salt, or polymer which may be hydrolyzed in situ, provides an effective water treatment composition. These polymer salts are useful when incorporated into laundry and dishwashing detergents as suspending agents or to prevent metal salt deposition on clothing, glassware or metal objects. The salts may be incorporated in oral health care products to prevent the accumulation of tartar on the teeth or on porcelain objects used in the mouth. Zinc salts are very useful in oral health care. They are especially useful in dentrifice compositions for inhibition of tartar deposition in effective amount of the salts of the polymers in combination with an orally acceptable dentrifice composition compatible with said salt, and more especially in the form of an oral hygiene formulation such as mouthwashes, rinses, irrigating solutions, abrasive gel dentrifices, nonabrasive gel dentrifices, denture cleansers, coated dental floss, interdental stimulator coatings, chewing gums, lozenges, breath fresheners, foams and sprays. They are useful in treating cloth and fibers as warp sizing compounds.
The addition of the polymer itself to the detergent formulation may be desirable where the pH of the detergent is sufficient to cause hydrolysis of the polymer yielding the salt in situ.
One object of this invention is to provide novel compositions useful as solubilizing agents, dispersing agents, emulsifying agents, rust-proofing agents, fiber-treating agents, level dyeing agents and retarding agents, inhibitors of scale deposition, inhibitors of corrosion of ferrous metals, inhibitors of scale formation in hard water, boiler water, cooling water, oil well waters, agricultural sprays and irrigation water and as builders and dispersants in detergent formulations.
Another object is to provide a method of producing these novel polymers.
Yet another object is to provide compositions suitable for incorporation in oral health care products for the inhibition of dental calculus.
A final object is to provide methods for preventing scale formation which are effective, low in cost, and environmentally benign.
DETAILED DESCRIPTION OF THE EMBODIMENTS
EXAMPLE 1
A solution of 39.2 g (0.4 moles) of maleic anhydride in 40 ml of water were stirred at 25°-75° C. for 45 min to give a white slurry of maleic acid. To this slurry was added 42 g of 30% aqueous ammonium hydroxide (0.36 moles NH 3 , 90% of theoretical required) with stirring and cooling. The resultant clear solution was then tumbled at 180°-200° C. (salt bath temperature) for 10 min to give a tan solid. The solids were pulverized and tumbled for 10 min at 200°-225° C. Once again the solids were pulverized and then tumbled at 225°-240° C. for 10 min. Finally, the solids were pulverized and tumbled for 10 min at 230°-240° C. to give 39.3 g of tan powder which was insoluble in water.
EXAMPLE 2
The procedure of Example 1 was repeated using 35 g of 30% aqueous ammonium hydroxide (0.3 moles NH 3 , 75% of theoretical required) to give 39.3 g of pink-tan powder which was insoluble in water.
EXAMPLE 3
The procedure of Example 1 was repeated using 23.5 g of 30% aqueous ammonium hydroxide (0.2 moles NH 3 , 50% of theoretical required) to give 37.8 g of pink-tan powder which was insoluble in water.
EXAMPLE 4
The procedure of Example 1 was repeated using 11.6 g of 30% aqueous ammonium hydroxide (0.1 moles NH 3 , 25% of theoretical required) to give 36.3 g of pink-tan powder which was soluble in water.
EXAMPLE 5
Four gram portions of the solids from Examples 1-4 were each dissolved 9.0 g of water containing 1.25 g of NaOH to give clear red-brown solutions, pH 7.5-8.5, estimated to contain 36-37% solids. Gel permeation chromatography (GPC) was run on a 1 cm ×18 cm, Sephadex G-50 column in a mobile phase of 0.02 M sodium phosphate buffer, pH 7.0, running at 0.5 ml/min, with detection in the UV at 240 nm. Table 1 shows the results which were obtained.
TABLE 1______________________________________Sample Residence time (min)______________________________________Example 1 21.5Example 2 21.0Example 3 23.0Example 4 31.0______________________________________
EXAMPLE 6. Preparation of a maleic polymer with a polyamine
To a solution of 4.6 g (0.025 moles) of lysine in 40 g of water containing 1.0 g of NaOH was added 39.2 g (0.4 moles) of maleic anhydride while stirring at 70°-75° C. for 10 min to give a pale yellow slurry of maleic acid. To this slurry was added 5.0 g (0.29 moles) of anhydrous ammonia with stirring and cooling. This solution was then treated with heat as in Example 1 to give 44.0 g of pink-tan powder which was insoluble in water.
A 4.0 g portion of the powder was dissolved in a solution of 9.0 g of water containing 1.3 g of NaOH to give a clear red-brown solution, estimated to contain 36% solids. Addition of 0.55 g of 30% H 2 O 2 gave a clear yellow solution after 16 hrs at 25° C. Chromatography of this solution as in Example 5 gave a peak centered at 13 min.
To prepare a 100% ammonia sample for comparison purposes, this experiment was carried out in the proportions above except that 1 equivalent of ammonia was used (noted as 6a in the results).
EXAMPLE 7. Calcium sulfate inhibition assay.
The material to be tested as an inhibitor of calcium sulfate scale formation was added in the quantities indicated to a solution of 10 ml of calcium chloride solutions 17.3 g of CaCl 2 dihydrate in 800 g of water containing 33 g of NaCl). To this solution was then added 10 ml of sulfate solution (16.8 g of Na 2 SO 4 and 33 g NaCl in 800 ml of water). The mixture was then sealed and maintained at 65° C. for 16 hours. Finally the mixture was filtered through Whatman #2 paper and dried at 65° C. for 8 hours, after which the weight of precipitate was determined. The results in Table 2 were obtained.
TABLE 2______________________________________ percent of CaSO.sub.4 Inhibition of PrecipitationSample from equivalence 1.25 ppm 2.5 ppmExample Number of ammonia 0 ppm (mg ppt) (mg ppt)______________________________________blank 79.51 90 23 102 75 4.5 13 50 48 04 25 51 35a 100 37 196 75 49 286a 100 52 14polyaspartic acid 38 10______________________________________ a prepared by the method of Example 1 using 1 equivalent of ammonia
EXAMPLE 8. Inhibition of calcium carbonate precipitation by the calcium drift assay.
In this assay a supersaturated solution of calcium carbonate is formed by adding 29.1 ml of 0.55 M NaCl and 0.01 M KCl to 0.3 ml of 1.0 M CaCl 2 , 5 microliter of sample (100 mg of the aqueous solution in 10 ml of water) and 0.6 ml of 0.5 M NaHCO 3 . The reaction is Initiated by adjusting the pH to 8.55-8.65 by titration with 0.5 N NaOH. At three minutes, 10 mg of CaCO 3 is added and the pH is recorded. The decrease in pH is directly correlated to the amount of CaCO 3 that precipitates. The additive concentration in the final test solution is 2.7 ppm.
TABLE 3______________________________________Sample percent of CaCO.sub.3from equivalence DriftExample Number of NH.sub.3 (pH units)______________________________________blank 1.051 90 0.602 75 0.633 50 0.534 25 1.05a 100 0.886a 100 0.60polyaspartate 0.442000 mol. wt. polyacrylate 0.374500 mol. wt. polyacrylate 0.20______________________________________ a prepared by the method of Example 1 using 1 equivalent of ammonia
EXAMPLE 9. Dispersant activity.
Kaolin dispersion was run by placing the sample (final concentration of 20 ppm) in a 12×100 mm test tube containing 5 ml of deionized water and adding 40,000 ppm kaolin clay. The height of the suspended solids was measured and compared to a control in which no dispersant had been added. A higher value indicates better dispersancy. Table 4 gives the results.
TABLE 4______________________________________Sample percent of Kaolin clayfrom equivalence height (mm)Example Number of NH.sub.3 suspension settled______________________________________blank 0 151 902 75 47 3.53 50 48 2.54 25 48 2.5a 100 50 36a 100polyaspartate2000 mol. wt. polyacrylate 48 24500 mol. wt. polyacrylate 48 3______________________________________ a prepared by the method of Example 1 using 1 equivalent of ammonia
EXAMPLE 10 pH drift assay for calcium phosphate.
A solution which is supersaturated with calcium phosphate was prepared by adding 0.1 ml of previously prepared aqueous solutions of 1.32 M CaCl 2 dihydrate and 0.90 M NaH 2 PO 4 to 29.8 ml of distilled water, resulting in 4.4 mM Ca 2+ and 3.0 mM dissolved inorganic phosphorus. The reaction vessel is maintained at 25° C. There is considerable irregularity in the time necessary to begin precipitation. Calcium phosphate begins to crystalize within a few minutes of initiation (first drop in pH) and is transformed to hydroxyapatite, Ca 10 (PO 4 ) 6 (OH) 2 , with a consequent downward pH drift (second drop in pH). The reaction ceases when the reactants are depleted and the pH ceases its downward drift. The samples prepared in Examples 1-4 and 6 were tested and the results (the average of two separate runs) are given in Table 5.
TABLE 5______________________________________Sample from percent of InductionExample equivalence periodNumber of ammonia (min)______________________________________blank 17.5 100 34.51 90 30.52 75 413 50 344 25 29.5a 100 26.56 75 34.56a 100 27polyaspartic acid 37______________________________________ a prepared by the method of Example 1 using 1 equivalent of ammonia
EXAMPLE 11. Maleic anhydride with 99% of a theoretical equivalent of NH 3
Maleic anhydride, 39.2 g (0.4 moles) dissolved in 40 g of water was added to 43.1 g of aqueous NH 4 OH (6.7 g NH 3 , 0.394 moles) and tumbled at 180°-195° C. for 8 min to give a clear pink melt. It was then heated to 185°-200° C. for 10 min to give a pink foam. The pulverized foam was heated for 10 min at 200°-235° C. to give a pink powder and then heated at 235°-245° C. for 10 min to give 38.5 g of a pink tan powder. The material was hydrolyzed with aqueous NaOH. The GPC gave a peak at 23 min. In the CaSO 4 assay of Example 7, the blank was 83 mg while the sample at 2.5 ppm gave a precipitate of 11 mg and at 1.25 ppm it gave a precipitate of 41 mg. In the Kaolin dispersion test of Example 9, at 20 ppm the height of suspended solids was 48 mm whereas the blank was 0 mm.
EXAMPLE 12. Maleic anyhydride with 5% of a theoretical equivalent of NH 3
Maleic anhydride, 39.2 g (0.4 moles) dissolved in 40 g of water was added to 4.3 g of aqueous NH 4 OH (0.34 g NH 3 , 0.02 moles) and tumbled at 180°-195° C. for 12 min to give a tan melt. It was then heated to 200°-225° C. for 10 min to give a tan melt. The melt was heated for 10 min at 220°-230° C. to give 18.1 g of brown solid. The material was hydrolyzed with aqueous NaOH. In the CaSO 4 assay of Example 7, the blank was 80 mg while the sample at 2.5 ppm gave a precipitate of 50 mg and at 1.25 ppm it gave a precipitate of 78 mg.
EXAMPLE 13. Preparation of a maleic polymer with a polyamine
To a solution of 1.9 g (0.025 moles) of ethylene diamine in 40 g of water containing 1.0 g of NaOH was added 39.2 g (0.4 moles) of maleic anhydride while stirring at 70°-75° C. for 10 min to give a white slurry of maleic acid. To this slurry was added 21.7 g of water containing 1.7 g (0.1 moles) of ammonia with stirring and cooling. This solution was then heated for 15 min at 170°-200° C. to give a tan melt. The melt was heated at 200°-225° C. for 10 min to give 36.5 g of a tan melt. It was further heated at 225°-235° C. for 10 min to give 35.4 g of tan melt which was not soluble in water.
The powder was dissolved in a solution of 9.0 g of water containing 1.3 g of NaOH to give a clear red-brown solution, estimated to contain 36% solids. In the CaSO 4 assay of Example 7, the blank was 80 mg while the sample at 2.5 ppm gave a precipitate of 22 mg and at 1.25 ppm it gave a precipitate of 66 mg. The GPC showed a peak at 29.5 min with a broad shoulder at 21-25 min.
EXAMPLE 14. Preparation of a maleic polymer with maleamic acid.
A solution of 9.8 g (0.1 mole) maleic anhydride in 40 g of water was stirred 45 min at 75°-25° C. To this solution was added 34.5 g (0.3 mole) of maleamic acid. The slurry was tumbled at 180°-195° C. for 10 min. All of the solids dissolved to give 39.9 g of a viscous red-tan syrup. Upon further heating for six 10 min periods at 180°-245° C., a tan powder, insoluble in water, was obtained. A 3.9 g portion was dissolved in 10 g of water containing 1.6 g of NaOH. The GPC showed a peak at 22.5 min. In the CaSO 4 assay of Example 7, the blank was 86 mg while the sample at 2.5 ppm gave a precipitate of 11 mg.
EXAMPLE 15. Preparation of a maleic polymer with diethylene triamine and oleic acid.
A mixture of 2.0 g (0.0175 moles) of diethylene triamine and 1.13 (0.0195 moles) of oleic acid was heated with stirring for 10 min at 190°-210° C. The resulting oil was dissolved in 50 g of methanol. To this solution of 9.8 g (0.1 mole) maleic anhydride in 40 g of water was stirred 45 min at 75°-25° C. To this solution was added 39.0 g (0.4 mole) of maleic anhydride. The reactants were stirred 45 min, following which 4.3 g (0.25 mole) of ammonia in 20 g of water was added (75% of an equivalent). The slurry was tumbled at 170°-185° C. for 10 min. Upon further heating for four 10 min periods at 190°-245° C., 42.3 g of a tan powder, insoluble in water, was obtained. A 4.0 g portion was dissolved in 10 g of water containing 1.6 g of NaOH. The GPC showed two broad peaks at 14 and 24 min. In the CaSO 4 assay of Example 7, the blank was 86 mg while the sample at 2.5 ppm gave a precipitate of 8 mg. In the Kaolin dispersion test of Example 9, at 20 ppm the height of suspended solids was 48 mm whereas the blank was 0 mm.
EXAMPLE 16. Preparation of a maleic polymer with oleyl amine.
To a solution of 2.67 g (0.01 mole) oleyl amine in 50 g of methanol was added 39.2 g (0.4 mole) maleic anhydride with stirring for 45 min at 25° C., following which 5.0 g (0.29 mole) of ammonia in 20 g of water was added (75% of an equivalent). The slurry was tumbled at 170°-195° C. for 10 min. Upon further heating for four 10 min periods at 200°-235° C., 41.4 g of a brittle glass, insoluble in water, was obtained. The material was dissolved in 100 g of water containing 16 g of NaOH. To this solution was added 5.5 g of 30% H 2 O 2 . After 16 hrs at 25° C., the solution was a clear yellow color. The GPC showed a peak at 14 min. In the CaSO 4 assay of Example 7, the blank was 86 mg while the sample at 2.5 ppm gave a precipitate of 9 mg.
It will be apparent to those skilled in the art that the examples and embodiments described herein are by way of illustration and not of limitation, and that other examples may be utilized without departing from the spirit and scope of the present invention, as set forth in the appended claims.
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Polymers of maleic acid may be prepared by thermally polymerizing malic acid, maleic acid or fumaric acid with less than one equivalent of ammonia. The polymers are modified by the incorporation of amines, carboxylic acids or combinations thereof. The polymers formed are excellent inhibitors of alkaline earth salt deposition, dispersants, tartar control additives, detergent additives, and water treatment agents.
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This is continuation-in-part of application Ser. No. 08/605,728, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a storage compartment device and more particularly to a portable storage compartment, having a slidable screen attached thereto, that is adapted to be removably secured to an under surface, such as the under surface of an existing upper cabinet, book shelf or the like. Additionally, the present invention includes a unique elbow means for allowing the user to easily and successfully manipulate the slidable screen of the storage compartment, even if the present invention includes a substantially rectangular configuration, inherently rendering the screen to travel around a bend.
2. Description of the Prior Art
For years individuals have relied on counter space in a kitchen for storing and maintaining appliances, such as blenders, coffee makers, and the like. This arrangement will enable the appliances to be easily accessible to the residence of the home. Counters in kitchens are also used for storing and maintaining food products, such as fruits, vegetables, chips, or the like. This arrangement will, like the appliances, provide easy accessibility to the edible items. At times, these items located on the counter will give the appearance of clutter, rending the room to seem messy and untidy.
Accordingly, efforts have been made to provide for an aesthetically pleasing means for camouflaging items on a kitchen counter. Such means that is commonly done is to provide a cover for a particular item. Typically, this cover is commonly used for appliances and is fabricated from a cloth or cloth like material. Though adequate in covering the item and protecting the appliance from dust, grease, and debris, the cover will still enable individuals to recognize the item being cover, inherently defeating its purpose. Additionally, the covers available on the market today are also limiting in design and styles, which in turn is limiting to the consumer.
Yet another commercially available product is a storage compartment, commonly known as an appliance garage, which is obtainable via cabinet makers or the like. These appliance garages are secured between the upper cabinets within a kitchen and the counter. The garages consists of two side walls and a front door located therebetween. The side walls are permanently affixed to the existing cabinets and counter, while the door is mounted on a door frame. The door is slideably mounted to the frame and is adapted to slide upwardly to expose the interior of the garage. Though efficient at hiding conventional appliances, these garages are expensive and can be difficult, if not impossible, to retrofit into an existing kitchen cabinet lay out. Since the height between the upper cabinet and counter can vary from kitchen to kitchen, these storage compartments must be customized per kitchen which inherently adds to the expense of the garage. Further still, since the side wall and frame are permanently attached to the existing upper cabinet and counter, cleaning inside the garage is awkward and difficult.
Hiding clutter or having privacy is a common concern to many individuals. Since costs and versatility are deciding factors for many consumers, various products have been develop with those particular concerns in mind. One popular product which provides privacy at a reasonable price, and offers a means of concealing, is the multi-panel folding door. Such a door is disclosed in British Patent No. 846,242 issued to Paulsrude et al. This door device, like the ones commercially available today, includes a header and side members which are attachable to a door frame. A track is located on the header. Slidably mounted within the track is a foldable screen. This device, like the conventional models, is ideal for use within a doorway. Unfortunately, this product, like the ones available on the market today, fail to disclose a means of allowing the screen to slide smoothly around a corner. Additionally, the use of the header and side members provides a device which is bulky and difficult to maneuver and install in small areas. Further, this device, like the others, does not disclose a compact nor portable unit which is easy to use and which can be customized by the consumer.
Accordingly, none of these previous efforts provide the benefits intended with the present invention, such as providing a storage compartment that can be removably secured to an upper cabinet or the like. Additionally, prior techniques do not suggest the present inventive combination of component elements as disclosed and claimed herein. The present invention achieves its intended purposes, objectives and advantages over the prior art device through a new, useful and unobvious combination of component elements, which is simple to use, with the utilization of a minimum number of functioning parts, at a reasonable cost to manufacture, assemble, test and by employing only readily available material.
SUMMARY OF THE INVENTION
The present invention provides for a storage compartment that is adapted to be removably secured to an under surface, such as the under surface of an existing upper cabinet, book case, self, or the like. The storage compartment of the present invention includes an upper frame and a tracking means which is secured to a screen means. The upper frame is secured to the desirable under surface and will receive the tracking means. This arrangement will allow the screen means to slide from an open position, for revealing the encompassed space defined by the frame, to a closed position, for concealing the items within the encompassed space.
The upper frame includes various components which are interlocking with each other. Each component has a substantially closed or C-shape configuration having a top planar surface with opposite ends and curved walls extending downwardly from each opposite end. The top planar surface is adapted to be secured to the particular under surface, such as the under surface of an existing upper cabinet, book case, self, or the like.
Each component of the frame includes mating means for allowing the frame to interlock properly. The frame comprises at least one elongate member and at least one elbow member. The use of the elongated member and elbow provides a frame which can be customized to include a perpendicular portion. The perpendicular portion will provide for a device which allows smooth transition of the screen means on the frame, even at a right angle.
The tracking means is secured to the screen means and is also adapted to be received within the frame. This will enable the screen means to be slideably attached to the frame.
The screen means is structured so as to slide on the frame. As a result, this screen means must be fabricated so as to be collapsible as well as being compact when in a closed and folded position. The screen is multi-paneled and comprises a plurality of rigid panels and flexible panels, alternatively disposed. This alteration of rigid and flexible panels provide a device which is designed and configured to be customized by the user by enabling the user to adjust the width of the screen by either cutting off a flexible panel or by slidably removing a unit. A unit comprises a flexible panel secured to a rigid panel.
Accordingly, it is the object of the present invention to provide for a storage compartment that will overcome the drawbacks, disadvantages, and shortcomings of prior storage compartments and methods thereof.
It is yet another object of the present invention to provide for a storage compartment which will adequately and efficiently conceal a multiplicity of items, such as, but not limited to, compact kitchen appliances (i.e. blenders, coffee makers, bread machine, food processor, etc.), televisions, computers, children's tools, offices supplies, and the like. Further this invention will provide for a storage compartment which will not be secured to the surface maintaining the particular item(s) to be conceal, so as to provide a device that is non-obtrusive which will enable easy removal and replacement of the stored item(s) as well as offer accessibility and cleaning capacity to the space defined by the frame.
Still a further object of the present invention is to provide for a storage compartment that can be retrofitted and customized below any existing and conventional shelving or elevated cabinet for providing a device which offers extra storage while concealing the items being stored. The final product is an aesthetically pleasing storage unit.
It is still a further object of the present invention to provide for a portable storage compartment which will successfully, conveniently and aesthetically store items on a surface, such as a counter or self, for freeing space in the conventional cabinets, drawers or self located typically in the kitchen, garage, laundry room, or the like.
Another object of the present invention is to provide for a storage compartment which will enable the user to open the screen means for temporarily unveiling additional counter and/or space when desirable.
Still a further object of the present invention is to provide for a storage compartment which includes a frame having an elbow for allowing the frame to extend around a corner and to provide for a smooth transition of the screen along the frame.
Yet another object of the present invention, to be specifically enumerated herein, is to provide a storage compartment in accordance with the preceding objects and which will conform to conventional forms of manufacture, be of simple construction and easy to use so as to provide a device that would be economically feasible, long lasting and relatively trouble free in operation.
Although there have been inventions related to storage devices, none of the inventions have become sufficiently compact, low cost, and reliable enough to become commonly used. The present invention meets the requirements of the simplified design, compact size, low initial cost, low operating cost, ease of installation and maintainability, and minimal amount of training to successfully employ the invention.
The foregoing has outlined some of the more pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and application of the intended invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, a fuller understanding of the invention may be had by referring to the detailed description of the preferred embodiments in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective view of the storage compartment of the present invention secured to the under surface of an existing cabinet.
FIG. 2a is a bottom view of an elongated member and elbow member of the frame, in a non-assembled position used in the storage compartment of the present invention.
FIG. 2b is a end perspective view of the elongated member of the frame used in the storage compartment of the present invention.
FIG. 2c is an end view of the elbow of the frame used in the storage compartment of the present invention.
FIG. 2d is a perspective detail view of the elbow of the frame used in the storage compartment of the present invention.
FIG. 3a is a side view of an example of the securing means for securing the frame to a surface.
FIG. 3b is a side view of another example of the securing means for curing the frame when the frame includes a flange member.
FIG. 3c is a side view of another example of the securing means for securing the frame to a surface.
FIG. 4a is a front plan view of the first embodiment of the screen used in the storage compartment of the present invention.
FIG. 4b is a front plan view of the second embodiment of the screen used in the storage compartment of the present invention.
FIG. 5 is a side view of the sliding mechanism used in the storage compartment of the present invention.
FIG. 6 is a front view of an alternative embodiment of the storage compartment of the present invention, including a spacer.
FIG. 7a is a top plan view of the first embodiment of the closure means of the present invention.
FIG. 7b is a top plan view of the second embodiment of the closure means of the present invention.
Similar reference numerals refer to similar parts throughout the several views of the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As seen in FIG. 1, the present invention comprises a storage compartment 10 that is adapted to be removably secured to the upper surface, such as a book case, self, or, as illustrated, an upper cabinet 12a. In this example, the device 10 will be located between the upper and lower cabinets 12a and 12b, respectively. The design and configuration of this storage compartment will provide for a device 10 that can aesthetically conceal items located on a counter top 14, or optionally, on a self or the like.
The present system has been employed successfully in the kitchen environment. For illustrative purposes, it will be illustrated the method for utilizing the present invention in the above identified environment. It is noted that this storage compartment can easily be retrofitted into a multiplicity of environments, including, but not limited to, book selves, desks, or the like.
The storage compartment includes a screen 16 that is slidably mounted to a frame 18. The frame 18 includes several components and is illustrated in further detail in figures in FIGS. 2a-3c. As seen in FIGS. 1-3c, this frame 18 is adapted to be secured to the lower surface of the upper cabinet 12a, as illustrated, a self, or the like. Thereby the countertop, or the resting surface, is not effected by this tracking system. This will eliminate any possibility of damaging the counter 14 or resting surface.
As seen in FIGS. 2a-3c, the frame 18 includes at least one elongated member 20 and at least one elbow 22. The elongated member 20, as shown, is straight and planar and includes opposite ends. For illustrative purposes, one end 24 is shown. The elbow is L-shape and, like the elongated member, includes opposite ends 26 and 28, respectively.
These ends 24, 26, and 28 located on the elongated member 20 and elbow 22 are designed and configured to interlock with each other. Inherently providing a device which can be customized. As seen in FIG. 1, the frame includes one elongated member and two elbows to provide for the device of the present invention to be attached angularly. The elbows will allow for a storage compartment to include a substantially rectangular configuration.
Located on each end of the elongated member, as seen in FIGS. 2a-3c, is a male extending means 30. Optionally this elongated member can include a male extending means on one end and a female extending means on the opposite ends.
The male extending means 30 is an extension of the elongated member, but which is smaller in size so as to be received easily within a female receiving means 32 of the elbow or optionally, other elongated member.
The female receiving means 32, illustrated in outline in FIG. 2a, is an opened end of the elbow and/or elongated member.
Each member includes a channel 34 that is defined by side walls 36. Each side wall 36 includes an extension or tab 38. A top wall 40 contacts the lower surface of the upper cabinet 12a. This top wall 40 will maintain and secure a securing means to enable the attachment of the frame to the cabinet. As seen, the channel 34 extends into each extension or male extending means 30. This will provide for the track to be continuous via channel 34 for preventing a stuck or malfunction while the screen is in transition within the channel.
As shown in the drawings, the female receiving means 32 is substantially identical in shape and structure as the channel, except it is larger in size. This design will provide for the male extension portion 30 to be received within the female receiving portion 32 to provide for the top wall 40 of each component to be linear and co-planar as well as providing for the channel 34 to properly aligned.
This frame can be fabricated from any durable material, such as aluminum, plastic, or the like. The frame can be packaged as a plurality of individual elongated frame members and a plurality of elbows. The elongated frame members can come in a variety of lengths so as to provide a device which can be customized according to the consumers needs and desires. Providing an assembly including a plurality of frame members having varied lengths and elbows of various angles provides for a user friendly device which is compact and portable.
The frame can be assembled prior to attaching it to the under surface of the upper cabinet or the like. In order to accomplish this, the ends are secured to each other via the male extending means 30 and female receiving means 32. The male extending means further include the channel 34 to provide for a continuous flow of the channel. This will provide for a smooth and non-intrusive transition of the screen means. By using the various sized elongated members 20 and optionally, the elbow 22, the user can obtained the desired shape and sized cabinet. Consequently forming a customized storage unit.
An end cap 42 can be inserted within the end of the female receiving means or the male extending means. The end cap is illustrated in FIG. 2c as being inserted into a female receiving means 32. The end cap 42 includes a front portion 44 and a rear portion 46. The front portion extends into the receiving means while the rear portion acts as a stop to prevent the cap from extending entirely into each channel. The front portion 44 is adapted to be received in the channel 34 to render the end cap to be snugly located within the channel 34 of the frame 18. The rear portion 46 of the plug will be flush with the outer ends of the frame 18 for rendering not only an attractive product but also a safe product which will cover the edges of the frame thereby eliminating any danger associated with contact with the edge, such as cuts or the like. This end cap can be fabricated from a polymer, such as rubber, and can be used for protecting the wall from scratches or the like which could occur with the ends of the frame or with the screen.
The frame is secured to the under surface of the upper cabinet, as illustrated, self, or the like, via a securing means 48. This securing means can comprise any conventional securing means. Examples of the various securing means are illustrated in FIGS. 3a-3c. As seen in FIG. 3a, the securing means 48 can provide for an a plurality of evenly spaced apertures 50 to extend through the top wall 40 of the track 18. These apertures can receive screws 52 for enabling the device to be secured to a particular surface, such as the under surface of a conventional cabinet. This type of securing means is ideal for use with a wooden surface.
Optionally, these apertures can be located through flanges 54 which extend outwardly from the top surface 40 of each component of the frame 18. Each flange 54 includes an aperture 56. The flange 54 of the elbow 22 is illustrated in FIG. 2d. This flange 54 is further illustrated in the cross-sectional view of the elongated member shown in FIG. 3b. By providing flanges 54 renders a device which is easy to install, thereby eliminating attaching the frame by way of the channel 34.
For individuals not wishing to alter their existing surfaces, yet another example is illustrated in FIG. 3c. As seen in this figure, hook and loop material (Velcro) 56 can be secured to both the top wall 40 of the track 18 and the under surface of the upper cabinet 12a. This design and configuration will render easy installation of the frame 18. Though not illustrated, other conventional forms of securing can be utilized, these forms include, but are not limited to, adhesives, double sided tapes, or the like.
The channel 34 of the frame is adapted to receive the tracking or sliding mechanism of the curtain. This sliding mechanism is constructed to slide freely within the channel. To prevent accidental removal or slippage of the sliding mechanism, the opposite ends of the frame can be provide with plugs 42. These plugs will provide for a natural stop for the sliding mechanisms. The plugs are only utilized when necessary, such as when an end of a frame is not contacting a wall or side wall of a cabinet.
A plug is illustrated in further detail in FIGS. 2c. It is noted that only one plug is illustrate and that a second plug is not illustrated in further detail since it would be substantially identical in structure and design as with the first plug.
The screen 16 is illustrated in further detail in FIGS. 1 and 4a-4b. As seen in these figures, the screen can is fabricated from a plurality of panels, alternating from a rigid panel 56 to a flexible panel 58. This alteration of material will provide for a device that is easily collapsible. As such, the rigid panel is wider than the flexible panel.
The lower edge of the screen is also designed not to contact the counter or lower surface. Hence, eliminating any need for a lower frame and also inherently providing for a gap to be located between the screen and the lower surface. This will eliminate the possibility of damaging the counter.
Each panel 56 and 58 includes a back surface 60 and a front surface 62. The front surface 62 is exposes in a closed position (see FIGS. 1 and 6). The back surface will be facing the items stored.
The back surface 60 can includes a plurality of evenly spaced markings 64. These markings are an indicating means for enabling the user to cut and customized the product efficiently and effectively. Accordingly, this will provide for the screen that can be customized in length.
The width of the screen 16 can also be adjusted. This adjustment can be accomplished by cutting at the flexible panel 58 at the appropriate distant (see FIG. 4a).
Optionally, flexible panel 58 can be slidably secured to a rigid panel 56, as seen in FIG. 4b. Hence, this will provide for one side of the rigid panel to be secured and attached to the flexible panel while the opposite side of the rigid panel 56 includes a channel 66 (illustrated in outline). This channel 66 is adapted to receive an extender 68 located on the flexible panel 58 for enabling the flexible panel 58 to be slidably located on the rigid panel. This extender is substantially rigid and is perpendicularly located on the flexible panel.
As seen in this figure, one side of the flexible panel is secured to a rigid panel while the opposite side includes the extender. This will provide for the flexible panel and rigid panel to be connected for forming a unit. This unit is designed to be slideably secured to other units. As shown in the drawings, the unit is an unitary and single member structure. This design and configuration of each unit will prohibit the flexible member from being removable from the rigid member per individual unit. Inherently decreasing the number of components for successfully employing the storage compartment of the present invention.
The use of both a flexible panel and a rigid panel provide a device for a screen which is collapsible. The flexible member bends as the device is opened. This will provide for front surface of a preceding rigid panel to contact the front surface of the succeeding rigid panel. The front surface of the preceding rigid panel will contact the front surface of the succeeding rigid panel, inherently providing for a collapsible screen.
At least two of the rigid panels will include a closing means (see FIG. 1). This closing means is illustrated and discussed in further detail in FIGS. 7a and 7b.
The sliding mechanism can be integral with each panel so as to provide for the sliding mechanism to extend upwardly from the top edge of each rigid panel. Optionally, opening 70 is located in the proximity of the upper edge of each rigid panel 56 so as to enable the sliding mechanism to be secured thereto. The sliding mechanism is illustrated in further detail in FIG. 5. As seen the sliding mechanism 72 includes an upper portion 74 and a lower portion 76. The upper portion is located within the channel of the frame. The lower portion includes an extension 78 that is adapted to extend into each opening and be secured in a fixed position within groove 80. This will provide for the extension to snap into a secured position within the groove. It is noted that the extension is illustrated as being enlarged. However, the extension can include any size or configuration so as to be received securely within the groove 80.
As stated previously, the sliding mechanism can be integral with the upper edge of the panel. This will provide for the shaft 82 of the sliding mechanism to extend upwardly from the top edge of each rigid panel for rending the upper portion 74 to be received within the channel. Thereby eliminating the use of the openings and the lower portion 76 of sliding mechanism.
This device is ideal for kitchens. Once secured on the lower surface of the upper cabinets, the user will still be able to clean their counter tops efficiently. The frame is not secured to the counter top, but rather to the lower surface of the upper cabinet. This will provide for the lower edge of the screen to not engage with the counter top, inherently enabling proficient cleaning within the garage as well and avoiding scratches and other permanent marking on the counter surface. By utilizing a continuous channel which extends into the interlocking means (male extending portion) provides a device which will efficiently allow the sliding mechanism to travel therein. Further, the elbow allows smooth transition of the sliding mechanism, even around a curved or angled frame. Due to the unique design of the frame member and tracking means, it is seen that the present invention is a product which is easily customized by the consumer and is adapted to be located anywhere, even between upper and lower shelves.
As seen in FIG. 6, the storage device of the present invention can be adapted to be utilized with counters that are equipped with back splashes, commonly used with laminate counter tops. As seen in this figure, the back splash 14' limits the screen from being flush with the side wall of the counter. This will provide for a gap to exist between the last panel of the screen 16 and the edge of the wall, inherently providing for a non-aesthetically pleasing affect.
To eliminate this gap, a shim or spacer 84 can be provided for enabling the user to attach the shim or spacer 84 to the side wall. This will not only eliminate the gap, but will provide for an aesthetically pleasing garage. This spacer 84 can be secured to the side wall of the kitchen via any conventional attaching means, such as, but not limited to adhesives, epoxies, VELCRO (hook and loop material), tape, or the like.
Yet another means for eliminating this gap would be to cut the last panel shorter so as to enable this last panel or a portion of the last panel to be located above the back splash 14'.
The closing means is utilized for enabling the garage to remain in a closed and stored position when items are being stored. This will enable items to be out of view, so as to provide for an area that is neat and clutter free. In order to provide for the screen to remain in a closed and secure position, the garage is provide with a closure means 86. This closure means is illustrated in further detail in FIGS. 1, 6 and 7. As seen in these figures, the closure means includes handles 88 located exteriorly on the screen. Located on the edge of two of the panels are magnets 90 (see FIG. 7b). These magnets are adapted to engage each other for providing the device to be in a closed position. Optionally, one magnet can be placed on an outer surface while the second can be placed on an inner surface so as to provide for one side of the screen to over lap a second side of the screen (see FIG. 7a).
In order to utilize the garage of the present invention, the user merely cuts the frame to the desired and appropriate size. The frame is secured to the lower surface of a cabinet or upper shelf via the securing means. This frame defines the storage area. The screen is then adjusted to a certain length and width. The tracking means is secure to the screen and then slid into the frame. If a spacer is to be utilized, then the spacer is attached to the side wall. Hence, the garage is adapted to be used for storing and maintaining items. Accordingly, the garage of the present invention provides a device that is easy to use, useful and renders an aesthetically pleasing environment.
While the invention has been particularly shown and described with reference to an embodiment thereof, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention.
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The present invention is a portable storage compartment which is adapted to be removably secured to the under surface of an existing upper cabinet. The storage compartment of the present invention includes an upper frame and a tracking system which is secured to a collapsible and foldable screen. The tracking system is secured to the screen and is also received within the frame. This will enable the screen to be slideably located on the frame. The screen is multi-paneled and comprises a plurality of rigid panels and flexible panels, alternatively disposed. This alteration of rigid and flexible panels provide a device which is designed and configured to be customized by the user by enabling the user to adjust the width of the screen by either cutting the off a flexible panel or by slidably removing a panel. The present invention will successfully, conveniently and aesthetically stored items on a counter while freeing space in the conventional cabinets and drawers located in the kitchen, garage, laundry room, or the like.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is related to U.S. patent application Ser. No. 09/079,042 U.S. Pat. No. 6,351,751 filed on May 14, 1998, entitled “PERSISTENT STORAGE MANAGERS FOR CONFIGURATION CLIENT/SERVER ENVIRONMENTS;” U.S. patent application Ser. No. 09/079,501 U.S. Pat. No. 6,161,125 filed on May 14, 1998, entitled “A GENERIC SCHEMA FOR STORING CONFIGURATION INFORMATION ON A CLIENT COMPUTER;” U.S. patent application Ser. No. 09/079,103 U.S. Pat. No. 6,233,582, filed on May 14, 1998, entitled “PERSISTENT STORAGE INTERFACE FOR A CONFIGURATION OBJECT-BASED SYSTEM;” U.S. patent application Ser. No. 09/079,499 U.S. Pat. No. 6,119,157, filed on May 14, 1998, entitled “A PROTOCOL FOR EXCHANGING CONFIGURATION DATA IN A COMPUTER NETWORK;” and U.S. patent application Ser. No. 09/079,500 U.S. Pat. No. 6,052,720 filed on May 14, 1998, entitled. “A GENERIC SCHEMA FOR STORING CONFIGURATION INFORMATION ON A SERVER COMPUTER;” and U.S. Provisional Application No. 60/085,425, filed on May 14, 1998, entitled “JAVA SYSTEM DATABASE,” which are all incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates generally to methods and apparatus for providing application programming interfaces in computer systems. More particularly, the present invention relates to a core application programming interface suitable for use by different application programming interfaces in a computing system.
2. Description of the Related Art
The use of networked computing systems is increasing as the use of personal computers is becoming more prevalent. By networking, or otherwise linking, computer systems together, resources such as software applications may be shared by multiple users, i.e., computer systems. The sharing of resources over a network generally enables each networked user to more efficiently utilize and allocate resources that are local to the user.
In an effort to consolidate resources in a networked computing system, network computers are being developed. Such network computers are typically used as clients within a network. Network computers are generally systems which are arranged to access and operate using mostly remote databases and resources, which are often servers on the network. Typically, a platform such as a network computer does not have local access to a writable storage device, e.g., a disk drive. As such, a user who uses a network computer may access and store information on a remote database that is shared by any number of users. As a result, it is not necessary for the network computer to, for example, have significant writable local storage capabilities.
The interfaces, e.g., application programming interfaces (APIs), associated with allowing applications, or entries, to be published on and retrieved from a shared database often include a relatively large number of methods. For example, a group of methods are typically needed to allow a client to publish entries to, search for entries on, and retrieve entries from a shared database. Similarly, a group of methods are generally needed to allow a server to publish entries to, search for entries on, and retrieve entries from a shared database.
Resources needed to provide the methods used to publish entries, search for entries, and retrieve entries may be significant. Specifically, keeping the functionality associated with a client API and the functionality associated with a server API on a system database may require a substantial amount of resources on the system database. In general, some of the methods associated with a client API and the methods associated with a server API are common. That is, some methods are the same irregardless of whether they are implemented with respect to a client or implemented with respect to a server. Therefore, essentially separately maintaining the functionality for a server API and a client API may be inefficient as it may be difficult to maintain consistency of use and function of the relevant methods.
A method is typically associated with a specific class or interface. Classes and interfaces are arranged in hierarchies, i.e., class hierarchies. In particular, classes and interfaces that are associated with a client API are part of one hierarchy, while classes and interfaces that are associated with a server API are part of another hierarchy. Hence, in some cases, the same class type may be associated with two different class hierarchies. Such redundancy in class type, like redundancy in methods, may be undesirable in terms of maintaining consistency of use and consistency in the functions of the classes.
As such, what is desired is a method and an apparatus for efficiently organizing class hierarchies and APIs on a system database. Specifically, what is desired is a method and an apparatus for developing a core API and, hence, a class hierarchy, for use with a system database such that resources may be efficiently used on the system database.
SUMMARY OF THE INVENTION
The present invention relates generally to defining a class hierarchy which allows a core application programming interface to be defined within an object based system. According to one aspect of the present invention, a class structure in an object based system is arranged to provide application programming interfaces which enable access to a system database. The class structure includes a first set of classes that define a core application programming interface, a second set of classes that define a client application programming interface, and a third set of classes that define a server application programming interface. The second set of classes includes the first set of classes, and the third set of classes includes the second set of classes. In one embodiment, the first set of classes includes interfaces. In such an embodiment, the interfaces may include an Entry interface.
In another embodiment, the first set of classes includes at least one abstract class and at least one concrete class. When the first set of classes includes abstract classes and concrete classes, the abstract class may include a BaseEntry class, while the concrete class may include a SystemDatabase class, a SystemTree class, a Query class, and a PropertyQuery class. In such an embodiment, the second set of classes may include a SystemEntry class that is a concrete class.
These and other advantages of the present invention will become apparent upon reading the following detailed descriptions and studying the various figures of the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a diagrammatic representation of relationships associated with a system database in accordance with an embodiment of the present invention.
FIG. 2 i s a diagrammatic representation of an interface and class hierarchy which may be used to implement entries within a system database in accordance with an embodiment of the present invention.
FIG. 3 a is a diagrammatic representation of the interactions between a client, a server, and a system database in accordance with an embodiment of the present invention.
FIG. 3 b is a diagrammatic representation of a relationship between a server application programming interface, a client application programming interface, and a core application programming interface in accordance with an embodiment of the present invention.
FIG. 4 is a diagrammatic representation of class relationships associated with a core application programming interface in accordance with an embodiment of the present invention.
FIG. 5 is a diagrammatic representation of a computer system suitable for implementing the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
In a networked computing system which includes network computers that may access a shared system database, some methods are common to more than one application programming interface (API). By way of example, some of the methods associated with a client API and some of the methods associated with a server API are essentially the same. However, the functionality of such “shared” methods are generally maintained separately with respect to the system database. That is, the functionality associated with a single method may be maintained repeatedly on the system database. Maintaining a single method multiple times on the database may be inefficient in terms of allowing for consistency of use and function of the method.
Identifying a core set, or group, of methods that are common to more than one API associated with a system database, and, further, developing an associated core class hierarchy may allow the functionality provided by the class hierarchy to be consistently maintained. In particular, as many methods used for a server API and a client API are effectively the same, developing a “core API” of methods that are common to both the server API and the client API may allow the use of the methods and the functionality of the methods to remain consistent, as well as allowing for system database resources to be efficiently used.
Computing networks which are arranged to support network computers generally use a system database as a central component. In one embodiment, the system may be a Java™ system database (JSD). The JSD generally allows an operating system, system services, applications, and tools to store and retrieve configuration information on a Java™-based platform. Configuration information is arranged to describe, for example, the physical devices that are present in a machine associated with the JSD, the system software services that are installed, and the specific user and group application profile. The JSD effectively serves as a central repository to store, as well as access, substantially any information which is used for configuration purposes. Hence, using the JSD, applications and services may implement varied configurations.
FIG. 1 is a diagrammatic representation of relationships associated with a system database in accordance with an embodiment of the present invention. A system database 104 , e.g., a JSD, generally provides services to clients or, more specifically, users 108 . In other words, within a client-server environment, system database 104 effectively serves as a client-side configuration and communications hub. System database 104 serves as a central database in a network of computing systems with an associated core API of the present invention typically includes a hierarchy of entries, each of which is effectively an atomic unit of information that is identified by a path name. An entry in system database 104 may have one or more associated properties, which are arranged to provide descriptions of the entries. In general, entries on system database 104 may be stored in trees.
System database 104 provides users 108 with services which may include, but are not limited to, information storage, information retrieval, and information publishing. Specifically, system database 104 typically allows users 108 to store, retrieve, and publish information relating to the configurations associated with users 108 .
Configurations, or configuration information, often includes information that describes devices or, more specifically, device drivers, which are effectively in communication with system database 104 . Such devices are generally associated with machines and users 108 . Configuration information may also include descriptions of system services, e.g., operating system (OS) system services 112 , that are available through system database 104 . In some embodiments, configuration information further describes selected group and user attributes, as well as substantially any necessary application-specific information that is associated with software applications 116 which are available to users 108 through system database 104 . It should be appreciated that applications 116 may include applets, such as those written in the Java™ programming language developed by Sun Microsystems, Inc., of Palo Alto, Calif.
In addition to being in communication with users 108 , system services 112 , and applications 116 , system database 104 is also generally associated with an OS kernel 120 . In the embodiment as shown, since system database 104 is a JSD, system database 104 is also associated with Java specific software including, for example, a Java OS, a Java Development Kit (JDK) and JavaBeans™. A JDK is a software development and execution environment, available commercially from Sun Microsystems, Inc., that may be used to write applications and applets in the Java programming language. JavaBeans™ are a portable, platform-independent reusable component model created in the Java programming language.
Referring next to FIG. 2, an interface and class hierarchy which may be used to implement entries with respect to a system database will be described in accordance with an embodiment of the present invention. An entry class hierarchy 202 includes interfaces 208 , an abstract class 210 , and concrete classes 214 . In one embodiment, entry class hierarchy 202 defines a public API. Interfaces 208 , as for example those in a Java environment, are a group of methods which may be implemented by several classes. In general, the classes which may implement the group of methods in interfaces 208 may be located substantially anywhere within an overall class hierarchy, as for example in an abstract class 210 such as a BaseEntry class. Abstract class 210 is a class which contains one or more abstract methods. Abstract methods are typically methods which have no associated implementation and, hence, may not be instantiated. Abstract class 210 is often defined such that other classes may extend abstract class 210 , and effectively make them “concrete” by implementing the abstract methods defined within abstract class 210 . Concrete classes 214 are classes which may be instantiated and be inserted into the system database. Further, concrete classes 214 are typically arranged such that concrete classes 214 may extend abstract class 210 .
In the described embodiment, abstract class 210 is a BaseEntry class. BaseEntry class 210 provides a public API implementation. As a result, BaseEntry class 210 enables a variety of tasks to be effectively centralized. By way of example, BaseEntry class 210 may allow tasks such as the creating of a transaction, the use of a transaction, and security to be centralized. BaseEntry class 210 also effectively implements an entry public API that may be accessed by a user, which is defined by an Entry interface 208 a and a TransactionFactory interface 208 b . In addition to implementing the entry public API, it should be appreciated that BaseEntry class 210 may also define additional APIs.
Although methods associated with BaseEntry class 210 may generally be varied, BaseEntry class 210 may include methods which obtain and return locks to entries in the system database as necessary. BaseEntry class 210 may further include methods that commit operations and abort operations. It should be appreciated that although methods are effectively defined by BaseEntry class 210 , the methods are invoked by other components associated with the system database, or directly by an application.
The public API implementation of insert methods, which are associated with BaseEntry class 210 , is intended to substantially allow for the insertion of “children” that are derived from BaseEntry class 210 . As a result, the entries published in the associated system database, as for example by a client or a user, are generally of a known heritage, or interface. Knowing the origin of substantially all entries in the system database, including those published by a client, enhances the robustness and security of the system database.
Each entry to a system database has entry attributes. While the entry attributes may vary, BaseEntry class 210 generally supports attributes relating to the name of an entry, the state of an entry, the parent of an entry, the children of an entry, the lock associated with the entry, the manager associated with the entry, and the generation number associated with the entry. In the described embodiment, the name of an entry is substantially a unique name, i.e., the name is unique among all siblings of the parent under which the entry resides.
The state of an entry generally refers to the states the entry may enter during the lifetime of the entry. Typically, an entry may enter three different states, namely a drafted state, a published state, and a deleted state. A drafted state exists when the entry is outside the bounds of a database, but within an associated object heap. In other words, a drafted state exists when an entry is created, but not inserted in a database. A published state refers to the state of the entry after the entry has been inserted into a database under a published parent. Once the entry is established within the database, the entry may then be located by an application or a system service using the name of the entry, or its properties, as searching criteria. A deleted state refers to the state of the entry when the entry is removed from the system database.
The attribute which is the parent of an entry is effectively a reference to the parent entry, while the attribute that is the child of an entry is a reference to at least one of the children of the entry. Substantially all entries have a single parent entry, with the exception of the super root of the system database, which is its own parent. It should be appreciated that when an entry is in a published state, the parent of the entry is non-null, while when an entry is in a drafted state, the parent of the entry may be null. When the parent of an entry is null, the indication is that the entry is the subtree root of a hierarchy of drafted entries.
The lock associated with an entry is typically a read-write lock that is intended to allow the entry to be inspected or modified without interference. Locks may be either shared locks or exclusive locks. That is, locks may be acquired for either shared or exclusive access. The manager associated with an entry is arranged to “set policy” for the entry, as the manager may perform security checks or otherwise affect the behavior of the entry.
The entry generation number is used to indicate whether the entry has been changed. In one embodiment, the entry generation number is a monotonically increasing number, e.g., a 32-bit number, that is incremented whenever the associated entry is modified in any way. As will be appreciated by those skilled in the art, modifying, or changing, an entry may be an insertion, a disconnection, or a removal of the entry within the database. A modification may also include any property additions, changes, or deletions.
A SystemEntry class 214 a is a concrete class that is associated with, e.g., a subclass of, BaseEntry class 210 . SystemEntry class 214 a includes methods associated with the implementation of methods that allow for the manipulation of properties associated with entries.
SystemEntry class 214 a is associated with a SystemAliasEntry class 214 b and a PersistentSystemEntry class 214 c . Entries associated with SystemAliasEntry class 214 b are generally used to reference other entries. That is, entries associated with SystemAliasEntry class 214 b are aliased entries. It should be appreciated that multiple aliases may refer to a single entry. PersistentSystemEntry class 214 c contains methods associated with manipulating properties associated with persistent entries. Additionally, PersistentSystemEntry class 214 c may also include methods associated with communicating with a server.
As previously mentioned, BaseEntry class 210 effectively implements an entry public API for operating on entries in the system database, as defined by Entry interface 208 a and TransactionFactory interface 208 b . TransactionFactory interface 208 b defines the service that is used to create transaction objects. Entry interface 208 a is arranged to extend TransactionFactory interface 208 b . In other words, the methods associated with Entry interface 208 a essentially add to the methods of TransactionFactory interface 208 b . Hence, the methods associated with TransactionFactory interface 208 b typically to specific entries.
In general, methods defined in TransactionFactory interface 208 b , which are implemented by BaseEntry class 210 , may vary widely. Methods include, but are not limited to, methods that create a shared transaction, and methods that create an exclusive transaction. Additionally, methods may include methods that determine modes of locks that are acquired on an entry, e.g., methods may determine whether a lock is shared or exclusive.
Entry interface 208 a is arranged such that each entry in a system database supports effectively all methods associated with Entry interface 208 a , as implemented by BaseEntry class 210 . A getName( ) method associated with Entry interface 208 a is arranged to return the name of an entry. An isDrafted( ) method is arranged to indicate whether or not an entry is drafted, an isPublished( ) method is arranged to indicate whether an entry is published, and an isDeleted( ) method is arranged to indicate whether an entry is deleted. Entry interface 208 a is also associated with methods which return information regarding persistence, current generations, parents, children, and, more generally, properties associated with an entry.
An isPersistent( ) method returns an indicator as to whether a particular entry is a persistent, e.g., non-volatile, entry or a transient, e.g., volatile, entry. Methods associated with Entry interface 208 a that return information regarding current generations include getGeneration methods which return the current generation of an entry. Methods which relate to the parents of entries include getParent methods that may be used to return the parent of a particular entry.
The methods which are associated with Entry interface 208 a and return information related to the children of an entry include getChildEntries methods that return an enumeration that is used to obtain references to the children of a given entry. An enumeration is a class which may be used to provide a list of information. Other methods that return information related to the children of an entry include getChildCount methods which return the number of children for a given entry, insert methods which are arranged to insert a specified entry as a child of another specified entry, disconnect methods which are arranged to disconnect a specified child entry from another specified entry, and remove methods which are arranged to remove a specified child entry.
Typically, the methods which are associated with properties may include getPropertyCount methods which count the number of properties defined for a specified entry, getPropertyNames methods which effectively obtain names for substantially all currently defined properties getPropertyValue methods which obtain property values for an entry, addProperty methods which add or change the value of a specified property, and removeProperty methods which remove specified properties from an entry. It should be appreciated that a method such as a getPropertyNames method may obtain names through an enumeration.
In a system which includes a system database, a client and a server are typically in communication with a system database through APIs. FIG. 3 a is a diagrammatic representation of the interactions between a client, a server, and a system database in accordance with an embodiment of the present invention. When a client 304 wishes to publish an entry onto a system database 308 , client 304 interfaces with a client API 312 to publish the entry using a network computer (NC) 316 . The application is published on system database 308 which, in the described embodiment, is a JSD, although it should be appreciated that system database 308 may generally be any suitable database. Client API 312 is also used by client 304 to retrieve or modify applications or, more generally, entries on system database 308 . Similarly, when a server 320 is to publish such entries as management information or administrative information on system database 308 , server 320 uses a server API 324 to publish the information. Server 320 also interfaces with server API 324 to retrieve or modify entries on system database 308 .
Although system database 308 has been shown as being a single, shared entity, in one embodiment, system database 308 may be such that there is a representation of system database 308 associated with client 304 , and a representation of system database 308 associated with server 320 . That is, client 304 and server 320 may each include a system database representation. For an overall system in which client 304 and server 320 include separate system database representations, e.g., separate JSDs, the representation on client 304 may be the same as the representation on server 320 .
In general, when client 304 and server 320 communicate with one another through system database 308 , the communication is performed using a client/server protocol 328 . Hence, when client 304 provides an entry to server 320 , client 304 uses client API 312 to effectively provide the entry to system database 308 . Then, using client/server protocol 328 , the entry is provided to server API 324 for transfer to server 320 .
As mentioned above, many of the interfaces and classes associated with client API 312 are substantially the same as the interfaces and classes associated with server API 324 . FIG. 3 b is a diagrammatic representation of the relationship between client API 312 and server API 324 in accordance with an embodiment of the present invention. As shown, client API 312 is effectively a subset of server API 324 . In other words, server API 324 includes substantially all interfaces and classes which are included in client API 312 . Hence, server API 324 includes substantially all methods associated with the interfaces and classes of client API 312 .
A core API 350 is defined within both client API 312 and server API 324 . That is, client API 312 and server API 324 are supersets of core API 350 . The interfaces and classes included in core API 350 will be described below with reference to FIG. 4 . In one embodiment, core API 350 may be defined as including interfaces and classes which are publicly accessible. That is, core API 350 may be a public API that includes methods and operations that are publicly available.
With reference to FIG. 4, the class relationships associated with a core API will be described in accordance with an embodiment of the present invention. A core API 402 generally includes interfaces 408 , abstract classes 410 , and concrete classes 414 . Interfaces 408 , abstract classes 410 , and concrete classes 414 were described above with respect to FIG. 2 . Interfaces 408 within core API 402 include an Entry interface 408 a , a TransactionFactory interface 408 b , and a Tree interface 408 c . Abstract classes 410 within core API 402 include a BaseEntry class 410 a and a Transaction class 410 b , while concrete classes 414 within core API 402 include a SystemDatabase class 414 d , a SystemTree class 414 e , a Query class 414 f , and a PropertyQuery class 414 g.
A client API 403 includes substantially all methods associated with core API 402 , as well as all methods associated with a SystemEntry class 414 a , which was described above with respect to FIG. 2 . It should be appreciated, however, that in some embodiments, client API 403 may be the same as core API 402 . That is, client API 403 may include only the methods defined in core API 402 . In the described embodiment, a server API 404 includes the methods of client API 403 , in addition to the methods of a SystemAliasEntry class 414 b and a PersistentSystemEntry class 414 c. SystemAliasEntry class 414 b and PersistentSystemEntry class 414 c were previously discussed with reference to FIG. 2 .
Entry interface 408 a and TransactionFactory interface 408 b essentially define a public API. Specifically, Entry interface 408 a and TransactionFactory interface 408 b define the public API, while BaseEntry class 410 a , SystemEntry class 414 a , SystemAliasEntry class 414 b , and PersistentSysterEntry class 414 c may effectively be published externally and are, in effect, visible to the public. Tree interface 408 c defines an interface which allows trees within a system database to be manipulated. While methods included in Tree interface 408 c may vary, the methods often include such methods as a getRootEntry( ) method that returns the root entry of a specified tree, a getCurrentEntry( ) method that returns the current entry for the specified tree, and a setCurrentEntry method that sets the current entry for the specified tree.
Methods associated with Tree interface 408 c further include “find” methods and “create” methods, in addition to various printing methods. Find methods generally include, but are not limited to, findEntry methods that are arranged to find an entry based on a specified path name and findDeepestEntry methods that are arranged to find the deepest existing entry of a specified path name. Create methods may include newAlias methods which are arranged to create a new alias with a specified path name, and newEntry methods that are arranged to create new entries, e.g., new system entries, using either the specified path name or a provided new name.
BaseEntry class 410 a , which is an abstract class, implements a public API as previously described. Core API 402 also includes Transaction class 410 b , which is an abstract class. Transaction class 410 b generally includes methods and constructors which are related to transactions performed on a system database. In one embodiment, transaction class 410 b includes an is Valid( ) method, a getOwnerID( ) method, a commit( ) method, and an abort( ) method. The is Valid( ) method is arranged to indicate whether or not a transaction is valid. A valid transaction is considered to be a transaction that has not yet been committed or aborted, as will be appreciated by those skilled in the art. The getOwnerID( ) method is arranged to return an identifier associated with the thread that created a particular transaction. The commit( ) method effectively commits a transaction such that substantially all associated changes to the system database are made visible, relevant events are produced, and held locks are released. Finally, the abort( ) method is arranged to abort a transaction and, hence, both “rolls back” any changes which were made by the transaction and releases any held locks.
Core API 402 includes a variety of different concrete classes. SystemDatabase class 414 d includes methods which are used to initialize and to return information associated with the system database. By way of example, SystemDatabase class 414 d may include a SystemDatabase( ) class which is arranged to initialize the system database, a getSuperRootEntry( ) method that is arranged to return the entry reference of a super root associated with the system database, and a getSystemDatabase( ) method that is arranged to return a tree that defines the system database. SystemTree class 414 e is arranged to implement methods defined by Tree interface 408 c . That is, SystemTree class 414 implements methods including, but not limited to, a getRootEntry( ) method that returns the root entry of a specified tree, a getCurrentEntry( ) method that returns the current entry for the specified tree, and a setCurrentEntry method that sets the current entry for the specified tree, as well as those previously described.
In one embodiment, Query class 414 f includes methods which are used to perform searches with respect to the system database. By way of example, Query class 414 f may generally include methods which query a root to determine all entries that match a specified scope. Query class 414 f may also include a setSearchScope( ) method which is arranged to change the scope of a search, a getSearchScope( ) method which is arranged to obtain the scope of a search, a getSearchName( ) method which is arranged to provide the entry name used in a search, a previousMatch( ) method which resets a query to the last match, and a getCurrentMatch( ) method which is arranged to return the current match, as well as numerous other methods. The other methods may include, but are not limited to, methods associated with returning results of different matches, e.g., the results of a previous match or the next match.
PropertyQuery class 414 g is an extension of Query class 414 f . In other words, the methods in PropertyQuery class 414 f may effectively override the methods of Query class 414 f . Methods contained in PropertyQuery class 414 g are typically arranged to provide search capabilities based upon entry property names. Specifically, the methods may include methods that are intended to search for any entries with a given property name within a specified scope.
FIG. 5 illustrates a typical, general-purpose computer system suitable for implementing the present invention. A computer system 530 includes at least one processor 532 , also referred to as a central processing unit (CPU), that is coupled to memory devices. Processor 532 may be part of a network computer, e.g., processor 532 may be in communication with a network computer. The memory devices may generally include primary storage devices 534 , such as a read only memory (ROM), and primary storage devices 536 , such as a random access memory (RAM).
As is well known in the art, ROM 534 acts to transfer data and instructions uni-directionally to CPU 532 , while RAM 536 is used typically to transfer data and instructions to and from CPU 532 in a bi-directional manner. Both primary storage devices 534 , 536 may include substantially any suitable computer-readable media. A secondary storage medium 538 , which is typically a mass memory device, may also be coupled bi-directionally to CPU 532 . In general, secondary storage medium 538 is arranged to provide additional data storage capacity, and may be a computer-readable medium that is used to store programs including computer code, computer program code devices, data, and the like. In one embodiment, secondary storage medium 538 may be a system database which is shared by multiple computer systems. Typically, secondary storage medium 538 is a storage medium such as a hard disk or a tape which may be slower than primary storage devices 534 , 536 . Secondary storage medium 538 may take the form of a well-know device including, but not limited to, magnetic and paper tape readers. As will be appreciated by those skilled in the art, the information retained within secondary storage medium 538 , may, in appropriate cases, be incorporated in a standard fashion as part of RAM 536 , e.g., as virtual memory. A specific primary storage device 534 such as a CD-ROM may also pass data uni-directionally to CPU 532 .
CPU 532 is also coupled to one or more input/output devices 540 that may include, but are not limited to, video monitors, track balls, mice, keyboards, microphones, touch-sensitive displays, transducer card readers, magnetic or paper tape readers, tablets, styluses, voice or handwriting recognizers, as well as other well-known input devices, such as other computers. Finally, CPU 532 may be coupled to a computer or a telecommunications network, e.g., an internet network or an intranet network, using a network connection as shown generally at 512 . With such a network connection 512 , it is contemplated that the CPU 532 may receive information from a network. CPU 532 may also output information to the network. Such information, which is often represented as a sequence of instructions to be executed using CPU 532 , may be received from and outputted to the network, for example, in the form of a computer data signal embodied in a carrier wave. The above-described devices and materials will be familiar to those of skill in the computer hardware and software arts.
Although only a few embodiments of the present invention have been described, it should be understood that the present invention may be embodied in many other specific forms without departing from the spirit or the scope of the present invention. By way of example, the client API may not necessarily be a “subset” of a server API. In some embodiments, a client API and a server API may overlap to define a core API, in lieu of a server API which includes all classes and interfaces associated with a client API. In other embodiments, the client API and the core API may be the same, i.e., all interfaces and classes in the client API may also be included in the core API.
As previously mentioned, a core API may be a public API. By way of example, referring back to FIG. 4, in one embodiment, a public API may include all interfaces and classes in core API 402 , with the exception of BaseEntry class 410 a . In another embodiment, as a client API may include only the classes and interfaces in a core API, i.e., the client API may be equivalent to the core API, the client API may effectively be a public API. Alternatively, a core API may include a protected API. The protected API may be considered to be a private API, as the associated methods are generally not visible externally.
While the relationship between a core API, a client API, and a server API has been described as having a server API which is a superset of a client API that is a superset of a core API, the relationship may vary without departing from the spirit or the scope of the present invention. For instance, a server API may not necessarily be a superset of the client API. That is, while the server API and the client API may both include a core API, the server API may not necessarily encompass the entire client API. Instead, the server API may encompass only a few of the classes or interfaces of the client API which are not included in the core API. Alternatively, the server API may include none of the classes of interfaces of the client API which are not already included in the core API.
The class hierarchy associated with a core API may generally vary. For instance, the class hierarchy may vary for embodiments in which there are either fewer or more classes associated with APIs. Similarly, the classes, as well as the methods, associated with different APIs may vary depending upon the requirements of a particular system without departing from the spirit or the scope of the present invention.
While arguments to methods, as for example entry interface methods and tree interface methods, have generally been described in terms pertaining to a specified entry it should be appreciated that the arguments used in the various methods described above with respect to FIGS. 2 and 4 may be widely varied. Some methods may take a specified transaction as an argument, while others may effectively create an anonymous transaction on behalf of the caller. Further, some methods may not take any arguments. Therefore, the present examples are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims.
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Methods and apparatus for implementing a core application programming interface which is a part of more than one application programming interface are disclosed. According to one aspect of the present invention, a class structure in an object based system is arranged to provide application programming interfaces which enable access to a system database. The class structure includes a first set of classes that define a core application programming interface, a second set of classes that define a client application programming interface, and a third set of classes that define a server application programming interface. The second set of classes includes the first set of classes, and the third set of classes includes the second set of classes. In one embodiment, the first set of classes includes interfaces.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to antenna arrays, and, more particular, to a particular antenna configuration wherein the radiation pattern of the antenna beam is shaped.
2. Prior Art
Artificial beam sharpening is known and can be used in conjunction with IFF (Identification Friend or Foe) interrogation antenna and in direction finding systems. Beam sharpening is an attempt to accurately control and define the volume of air space in which aircraft are being interrogated. Thus, artificial sharpening of beam patterns can eliminate ambiguity in direction finding systems and eliminate backlobe "punch through" in IFF systems as described below.
An established method of artificial beam sharpening compares the two signal levels simultaneously appearing at the sum and difference terminals of a hybrid in an antenna array capable of producing sum and difference beams. A valid response occurs only when signal processing within the interrogator-receiver unit determines that the sum beam gain exceeds the difference beam gain by a predetermined amount referred to as the sidelobe-suppression-level. Signal level comparisons which do not meet this criterion are rejected. In a well designed IFF antenna the sum beam gain is greater in the desired region of interrogation and, conversely, the difference beam gain is greater everywhere outside the desired region. When the sum beam sidelobes or backlobes exceed the difference beam sidelobes or backlobes by an amount greater than the sidelobe-suppression-level, "punch through" is said to exist and permits interrogation in undesired directions.
Punch-through can be reduced by increasing the sidelobe-suppression-level which is adjustable inside the interrogator-receiver unit; however, the volume of air-space which can be interrogated near the peak of the sum beam is also reduced, thus placing a limit on this option. Further reduction of punch-through can come from sum and difference pattern shaping.
Backlobe punch-through has been a persistent problem with the balanced array geometry typical of IFF interrogation antennas in current use due to the fore and aft symmetry of the difference pattern nulls. Past solutions to this problem have been directed toward a design perturbation which fills or shifts the difference pattern aft null without seriously disturbing the forward null position.
One known way of attempting to eliminate aft directed punch-through includes the use of an array sufficiently large to reduce aft directed radiation below -30 dB relative to forward directed radiation at both the sum and difference ports of the summing four port hybrid. This has the disadvantage of being overly large. Another prior art device for attempting to eliminate aft directed punch through utilizes auxiliary radiators directed toward the back of the array to perturb the null of the difference pattern in the aft direction. A device with such auxiliary radiators is very difficult to optimize because it is a patch work solution involving three radiating sources rather than a fundamental solution to the problem. It would be desirable to achieve beam sharpening which fundamentally solves the backlobe punch through problem without resorting to cut-and-dry design perturbations or having to use excessive sidelobe-suppression-levels. These are some of the problems this invention overcomes.
SUMMARY OF THE INVENTION
In accordance with an embodiment of this invention, rear "punch-through" problems can be eliminated and there can be formed a completely unidirectional "artificially sharpened" beam with no backlobe or sidelobe "punch-through". An antenna system in accordance with an embodiment of this invention used in conjunction with a standard four port hybrid coupler allows reception of signals along the forward axis and eliminates any signals from the back or sidelobes. The invention overcomes the backlobe reception that is present in prior art antenna systems of this type.
The invention includes two antenna arrays, each array having a pair of radiating means spaced according to one of two different equations. The spacing in one array is controlled by the equation λ(0.25-x) and the spacing in the other array is controlled by the equation λ(0.25+x), wherein λ is the wavelength of a signal applied to the antenna and x is the radiating means spacing differential in wavelengths. The first equation can produce an antenna array having a generally cardioid beam pattern with a backlobe having a positive phase. The second equation can produce an antenna array also having a generally cardioid beam pattern with a backlobe having a negative phase. Because both beam patterns have backlobes with aft directed peaks, signal processing by a four port hybrid coupler can be used to substantially eliminate backlobe punch-through. In particular, the signal processing can produce a difference pattern with an aft directed peak.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1a is a partly block diagram of an antenna system in accordance with an embodiment of this invention;
FIG. 1(b ) is a representation of the antenna beam pattern associated with each of the two antenna arrays in the antenna system of FIG. 1(a );
FIG. 1(c ) is a representation of the sum pattern and the difference pattern of the antenna beam patterns produced by the antenna system of FIG. 1(a ) in accordance with an embodiment of this invention;
FIG. 2 is a graphical representation of the elevation patterns of the left and right hand arrays of an asymmetrical endfire array antenna system in accordance with an embodiment of this invention;
FIG. 3 is a plan view of the computed sum and difference patterns of an 8-slot asymmetrical endfire antenna array for a differential wavelength spacing (x) of 0.02;
FIG. 4 is a plan view similar to FIG. 3 with x=0.04;
FIGS. 5a, 5b, 5c and 5d is a graphical representation of the on-axis peak to null transition region of the sum and difference backlobes versus elevation for x=0.04 at elevations of 120° in FIG. 5a, 140° in FIG. 5b, 160° in FIG. 5c and 180° in FIG. 5d.
FIG. 6 is a partly block representation of an antenna system similar to FIG. 1 wherein there are n-pairs of radiators;
FIG. 7(a) is a plan view of the slot configuration in the upper circuit board of an antenna sandwich in accordance with an embodiment of this invention;
FIG. 7(b) is a plan view of the lower circuit board of the antenna sandwich of FIG. 7(a) showing the hybrid feed circuit configuration;
FIG. 8 is a graphical representation of the measured sum and difference azimuth patterns of an 8-slot asymmetrical endfire array in accordance with an embodiment of this invention; and
FIG. 9 is a graphical representation on a polar plot of azimuth vs. elevation of punch-through.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1(a), an antenna system 10 includes a left hand array 11, a right hand array 16 and a four port hybrid coupler 21 coupled to arrays 11 and 16. Antenna system 10 is an eight slot differential backlobe array having four left hand slots 12, 13, 14 and 15 in left hand array 11 and four right hand slots 17, 18, 19 and 20 in right hand array 16. The four left hand slots 12, 13, 14 and 15 are arranged in two rows perpendicular to the forward direction spaced 0.21 wavelengths apart in a direction parallel to the forward direction and the four right hand slots 17, 18, 19 and 20 are also arranged in two rows and are spaced 0.29 wavelengths apart in a direction parallel to the forward direction. The two slots in the forward row of each half of the antenna (14, 15, 19 and 20) are excited with a phase delay equal to their respective spacings from the slots in the back row (12, 13, 17 and 18) to form forward directed, or endfire, beams having a generally cardioid sensitivity pattern with backlobes as pictured in FIG. 1(b). Because of the spacings chosen, the backlobe of the right hand array 16 is negative whereas the backlobe of left hand array 11 is positive with respect to the forward lobe. When the right hand pattern 28 and left hand pattern 29 are combined in the sum/difference hybrid 21, the resulting patterns observed at the output terminals of the hybrid are as pictured in FIG. 1(c).
Sum and difference hybrid 21 is connected to left hand array 11 and right hand array 16 by coupling a left input port 24 of hybrid 21 to left hand array 11, a right input port 25 of hybrid 21 to right hand array 16 so that a sum output port 23 produces a sum pattern 26 and a difference output port 22 produces a difference pattern 27. Sum pattern 26 exceeds the difference pattern 27 only in the forward direction so that no punch-through occurs in any other direction and interrogation and reply can take place in the forward direction. The elimination of the aft directed punch-through is made possible by the phase differential of the individual backlobes of the left hand pattern 29 and right hand pattern 28 of the array. In the aft direction, the difference pattern 27 peaks on axis and the sum pattern 26 forms a null on axis.
The transition from a forward peak to an aft null in the sum pattern 26 and, conversely, from a forward null to an aft peak in the difference pattern 27 can be visualized by referring to the elevation patterns shown in FIG. 2. The close-spaced slots 12, 13, 14 and 15 in the left array 11 form a single-lobed pattern 33 (dashed curve) having a greater forward gain than rearward gain, whereas the wide-spaced slots 17, 18, 19 and 20 in the right array 16 form a separate front lobe 34 and back lobe 35 (solid curve). The transition occurs at the elevation angle of the null between the front and back lobes formed by the right half of the array because of the phase reversal occurring at this point.
The elevation angle at which the transition occurs can be moved forward by increasing the right hand array 16 spacing while concurrently reducing the left hand array 11 spacing by a proportionate amount according to the following relationship:
D L /λ=0.25-x, and
D R /λ=0.25+x;
D L =Left half slot spacing in inches,
D R =Right half slot spacing in inches,
λ=Wavelength in inches,
x=Slot spacing differential in wavelengths
Calculated sum and difference azimuth patterns for an 8-slot endfire array having an amplitude taper of 3 dB are shown for x equal to 0.02 in FIG. 3 and for x equal to 0.04 of a wavelength in FIG. 4. Freedom from backlobe punch-through requires a sidelobe-suppression-level of only 1 dB for x=0.02 of a wavelength and 5 dB for x=0.04 of a wavelength. Sidelobe-suppression-levels typically are set at much larger values to achieve the desired level of artificial beam sharpening. To achieve the desired difference of phase of the backlobe it is advantageous to have x less than about 0.25.
FIGS. 5a, 5b, 5c and 5d shows computed backlobe patterns for x=0.04 of a wavelength at several different elevation angles to illustrate the on-axis peak to null transition region. At 120° elevation from the forward main beam, the sum pattern backlobe (solid curve) exceeds the difference pattern backlobe (dashed curve) by only 8 dB. At 140° elevation, the sum and difference backlobes have equal gain, and at 160° elevation, the sum pattern backlobe has developed an on-axis null 8 dB below the difference pattern backlobe.
In accordance with one embodiment of this invention shown in FIGS. 7a and 7b, and 8-slot asymmetrical array having a differential slot spacing of x=0.04 is fabricated of two one eighth inch thick printed upper and lower circuit boards 50 and 51 which are laminated together and bonded to a support structure (not shown). The 8-slots are etched in the top ground plane of the upper board 50 and the printed circuit feed network is etched in the top of the lower board 51. The printed circuit contains two 90° hybrids to form the endfire beams and a 180° hybrid to form the sum and difference azimuth beams. Impedance transformers within the circuit are designed to distribute power efficiently to the slots with a 3 dB amplitude taper across the array. Measured sum and difference azimuth patterns of the antenna are shown in FIG. 8. The leftward skew of the backlobe structure can be attributed to an amplitude unbalance between one or more pairs of fore and aft slots. A sidelobe-suppression-level of only 8 dB would eliminate all punch through in the measurement plane of these patterns.
More than 3000 patterns were measured and analyzed to determine the performance of an antenna in accordance with an embodiment of this invention. Transmit punch through was evaluated at 1.03 GHz at a sidelobe-suppression-level of 6 dB and receive punch through was evaluated at 1.09 GHz at a sidelobe-suppression-level of 9 dB. Joint punch through was determined as the area in which both transmit and receive punch through occurred simultaneously. The punch through results were displayed on polar-projection maps as shown in FIG. 9. For the condition shown, joint punch through was one percent. The average joint punch through was only 0.34 percent based upon an equal probability of an interrogation anywhere within the volume of airspace below 30° elevation. Backlobe punch through was found to be well controlled and minimized by the unsymmetrical slot array geometry. Although backlobe structure was sensitive to amplitude unbalance with the array, punch through objectives were not compromised.
Referring to FIG. 6 an antenna system 30 is similar to antenna system 10 of FIG. 1 but has more than two dipoles in both a left hand array 31 and a right hand array 32. Spacing between adjacent dipoles in each of the arrays is equal, and the number of dipoles in one array is equal to the number of dipoles in the other array. Although FIG. 6 shows the dipoles aligned in two rows, the dipoles can also be arranged in a column so that additional dipoles are added in a fore and aft direction.
Various modifications and variations will no doubt occur to those skilled in the various art to which this invention pertains. All antenna systems of left and right arrays of radiators composed of one or more rows containing one or more elements per row with array geometry arranged so that the left and right arrays produce oppositely phased backlobes are considered to be within the scope of this invention. For example, the combining of one or more dipoles in one half of the array with one or more slots in the other half of the array will produce oppositely phased backlobes and is a variation which basically relies on the teachings of this invention. A particular configuration of achieving a radiating element such as a dipole or slot, may be varied from that disclosed herein. Such variations and all variations which basically rely on the teachings through which this disclosure has advanced the art are properly considered within the scope of this invention.
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This specification discloses an antenna system with a left antenna array having a pair of radiators and a right antenna array having a pair of radiators. The spacing of the radiators is such that one antenna array produces a positive phase backlobe and the other antenna produces a negative phase backlobe. Appropriate processing of the signals from the two antenna arrays permits exclusion of any signal received in the backlobe of the two arrays. The spacing between the radiators in one array is determined by the equation λ(0.25 +x) and the spacing between radiators in the other array is determined by the equation λ(0.25 -x) wherein λ is the wavelength of an electrical signal applied to the antenna system and x is the radiator spacing differential in wavelengths.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. application Ser. No. 10/742,726 filed Dec. 19, 2003 (the entirety of which is incorporated herein by reference), which is a continuation of U.S. application Ser. No. 09/254,623, filed Jul. 8, 1999 (the entirety of which is incorporated herein by reference), which is the National Stage of PCT Application No. PCT/IB97/01091 filed Sep. 10, 1997 (which designated the U.S.) (the entirety of which is incorporated herein by reference), which claims the benefit of U.S. Provisional Application Ser. No. 60/025,179 filed Sep. 11, 1996 (the entirety of which is incorporated herein by reference).
[0002] The present invention comprises the method of treating a host organism (man or animal) in need of a drug having direct or prophylactic anti-neoplastic activity comprising the administration of a therapeutically effective amount of Phospholipase A 2 targeted venom anti-serum alone or in combination with a known Phospholipase C anti-serum or a Phospholipase C inhibitory compound. A vaccine containing in whole or in part snake or insect venom or mammalian PLA 2 components comprising epitopes demonstrating Phospholipase A 2 activity and/or Phospholipase C enzyme components. This patent presents therapeutic pharmaceutical formulations containing snake and/or insect venoms, or extracts from such venoms which contain, total or partial, phospholipase A 2 enzyme activity or PLA 2 epitopes. This patent presents therapeutic pharmaceutical formulations containing anti-serum to snake and/or insect venoms and/or mammalian PLA 2 enzymes wherein the anti-serum has been preferably affinity purified for use in treating patients suffering from neoplastic disease. This patent presents pharmaceutical formulations containing organic polymer mimic molecules generated to snake and/or insect venoms or the PLA 2 enzyme components thereof and/or PLA 2 enzymes isolated from insect, mammalian on plant cells, and/or Phospholipase C enzyme preparation or extract from such venoms which may contain, total or partial, phospholipase A 2 enzyme activity.
[0003] In this patent the affinity purified anti-serum to venoms Phospholipase A 2 (PLA 2 ) and mammalian or plant PLA 2 are shown to be active anti-proliferative neoplastic agents.
[0004] The present invention comprises the method of treating host organisms (i.e. human or animal) in need of a drug having anti-neoplastic activity comprising the administration of a therapeutically effective amount of venom anti-serum either alone or preferably in combination with a Phospholipase C inhibitor of non-toxic nature or monoclonal or polyclonal anti-serum to Phospholipase C enzyme or a vaccine containing in whole or in part venom and/or other components of animal, insect or plant origin showing Phospholipase A 2 and/or Phospholipase C activity. This patent presents pharmaceutical formulations containing snake and/or insect venoms, or extracts from such venoms which may contain, total or partial, Phospholipase A 2 enzyme activity alone or in combination with animal or plant Phospholipase A 2 with or without Phospholipase C inhibiting compounds or Phospholipase C mono or polyclonal anti-serum to Phospholipase C enzyme as therapeutic vaccine candidate for all neoplastic diseases. This patent presents therapeutic pharmaceutical formulations containing anti-serum to snake and/or insect venoms wherein the antiserum is preferably affinity purified for use in treating neoplastic diseases. This patent presents pharmaceutical formulations containing organic polymer mimic molecules generated to snake and/or insect and/or mammalian and/or plant PLA 2 enzymes or epitopes, or extract from such venoms or synthetic peptides and/or other molecules which may contain, total or partial, Phospholipase A 2 and C enzyme activity.
[0005] Phospholipase A 2 are lipolytic enzymes that hydrolyze the sn-2-acylester bond in glycerophospholipids. Many forms of PLA 2 exist in nature and have been described and classified into several groups. Types I, II and III PLA 2 are low molecular weight peptides (13-18 kDa) extra-cellular enzymes, including pancreatic and cobra venom PLA 2 (type I), rattle snake and inflammatory PLA 2 (type II) and bee venom type III. Intracellular cytosolic PLA 2 belong to different groups, including the 85 kDa (type IV) and 40-75 kDa enzymes.
[0006] Affinity purified anti-serum to venoms, animal or plant tissue demonstrating the ability to bind PLA 2 enzymes are shown herein below, by way of example, to be active in-vitro and in-vivo anti-proliferative neoplastic agents. Accordingly, these affinity purified antisera either alone or in combination with non-toxic Phospholipase C inhibitor or anti-serum to Phospholipase C are useful in the control of proliferation of neoplastic tissue.
BACKGROUND OF THE INVENTION
[0007] There is evidence to indicate that Phospholipase A 2 (PLA 2 ) is involved in the pathogenesis of many diseases. Thus local and circulating levels of Phospholipase A 2 enzyme and enzymatic products are elevated during infection, inflammatory diseases, tissue injury and brain dysfunction and is a very early indication of neoplastic development prior to tumour cell mass being evident by conventional methods of scanning tissue tumours.
[0008] Excessive Phospholipase A 2 activity may promote chronic inflammation, allergic reaction, tissue damage and pathophysiological complications. These effects may be the result of accumulating Phospholipase A 2 products (lysophospholipids and free fatty acids, e.g. Arachidonic Acid) and destruction of key structural phospholipid membrane components, but are potentated by secondary metabolites, such as eicosanoids and platelet-activating factor. Phospholipase A 2 products or lipid mediators derived therefrom have been implicated in numerous activities that are an integral part of cell activation; chemotaxis, adhesion, degranulation, phagocytosis and aggregation.
[0009] Phospholipase A 2 secreted excessively at local sites may be responsible for tissue damage common to rheumatic disorders, alveolar epithelial injury of lung disease and reperfusion.
[0010] During acute myocardial ischemia, cytosolic Phospholipase A 2 and Phospholipase C activation causes increased intracellular Ca 2+ . Subsequent accumulation of lysophospholipids and free fatty acids promote damage to sarcolemmal membranes leading to irreversible cell injury and eventually cell death.
[0011] Altered cytosolic Phospholipase A 2 and Phospholipase C activity or defects in their control and regulation is a predisposing factor to causing tumour cell development.
[0012] Prostaglandins and related eicosanoids are important mediators and regulators of both immune and inflammatory responses. Prostaglandin E 2 induces bone resorption and Leukotriene B 4 stimulates vascodilation and chemotaxis. Increased levels of Phospholipase A 2 is noted in Rheumatoid Arthritis (R.A.), osteoarthritis, gout, collagen and vascular diseases. Phospholipase A 2 induces non specific airway hyperactivity that is evident in asthma. Phospholipase A 2 is also elevated in peritonitis, septic shock, renal failure, pancreatis, Chrons and Graves Disease.
[0013] The activity of cell-mediated defense systems is stimulated by consecutive formation of interleukin 1β(IL-1β), interleukin-2 (IL-2) and interferon γ (IFN γ). The system is inhibited by interleukin-4 (IL-4) and also by prostaglandin E 2 (PGE 2 ) and histamine, which are released when the immune system is activated. The inhibition is strong in cancer patients, because PGE 2 is formed in many cancer cells and its formation is stimulated by IL-1β. PGE 2 and histamine are feedback inhibitors of cell mediated immunity.
[0014] PGE 2 is formed from arachidonic acid in monocytes, macrophages, cancer cells and other cells, when arachidonic acid is released from cellular phospholipids. The formation of PGE 2 is stimulated by several compounds, including histamine, IL-1 (α and β) and Tumour Necrosis Factor α (TNFα). PGE 2 inhibits the formation and receptor expression of IL-2 by increasing the level of cyclic AMP (cAMP) in helper T cells. This concomitantly decreases the formation of IFNγ.
[0015] PGE 2 inhibits the ability of natural killer cells (NK) to bind with tumour cells by increasing cAMP in Natural Killer Cells. This decreases tumour cell killing.
[0016] When the immune system is stimulated to destroy tumour cells, the killing is prevented because IL-1β stimulates PGE 2 formation in tumour cells, which increases cAMP levels in NK cells and prevents the binding of NK and tumour cells.
[0017] The activation of the cell-mediated defense is blocked also because PGE 2 -increases cAMP in helper T cells and inhibits the formation of IL-2 and IFNγ.
[0018] Cytotoxic T cells can also produce PGE 2 thus inhibiting the activity of NK cells.
[0019] A number of human and experimental animal tumours, contain and/or produce large quantities of prostaglandins (PG). Prostaglandins E 2 has been shown to effect significant cell proliferation in tumour growth and to suppress immune responsiveness.
[0020] Phosphatidylinositol specific phospholipase C is an important enzyme for intracellular signalling. There are at least three major classes of Phosphatidylinositol specific Phospholipase C (PtdlnsPLC: PtdlnsPLC β, γ, δ). PtdlnsPLCs hydrolyse a minor membrane phospholipid, phosphatidylinositol (4, 5) bisphosphate (Ptdlns (4,5) P 2 ) to give the second messengers inositol (1, 4, 5) trisphosphate (Ins (1, 4, 5) P 3 ), which releases Ca++ from intracellular stores to increase the intracellular free CA++ concentration, and diacylglycerol which activates the Ca++ and phospholipid-dependent protein serine/threonine kinase, protein kinase C. Proteins phosphorylated by protein kinase C include transcription factors. Together, the increase in intracellular free Ca++ concentration and the activation of protein kinase C lead to a series of events that culminate in DNA synthesis and cell proliferation in tumour cells.
[0021] A number of growth factors and mitogens, including platelet-derived growth factor (PDGF), epidermal growth factor (EGF) and bombesin, act through specific receptors to increase Ptd ins PLC activity in cells. Continued stimulation of Ptd lns PLC can lead to cell transformation.
[0022] Ptd lns PLC activity is found to be increased in a number of human tumours. 76% of human breast cancers have detectable Ptd lns PLC-γ immunoreactive protein compared to only 6% in benign breast tissue.
[0023] Cytosolic Ptd lns PLC activity is increased up to >4-fold in human non-small cell lung cancer and renal cell cancer compared to normal tissue.
SUMMARY OF THE INVENTION
[0024] The present invention comprises the method of treating mammals including humans in need of a drug to prevent neoplastic tissue growth and spread by the administration of a therapeutically effective amount of venom anti-serum prepared to whole venom or to parts of the venom or components of plant or animal origin which demonstrate PLA 2 activity. Also enhanced anti-cancer effects both in-vitro and in-vivo have been realised by combining this affinity purified anti-serum to PLA 2 components and/or mammalian PLA 2 with a non-toxic inhibitor of Phospholipase C or with anti-serum (polyclonal or monoclonal) developed to Phospholipase C enzyme.
[0025] This patent relates to the administration of one or more compounds which can generally be described as performing their function by either directly or indirectly causing Phospholipase A 2 and/or Phospholipase C enzyme inhibition, wherein the said inhibition is either partial or total. In addition this patent relates to the administration of one or more compounds which can generally be described as performing their function by interaction with the neoplastic cell membrane preventing their growth or spread, thus preventing further disruption of non-involved organs of the body and causing no toxicity to the infected patient or animal being treated.
[0026] Additional aspects of the invention relates to pharmaceutical compositions containing the compounds of the invention as active ingredients, modifying unwanted immune responses, and to methods of retarding proliferation of tumour cells using the compounds and compositions of this invention.
[0027] The anti-serum to snake venom PLA 2 and to plant, insect, mammalian and/or to PLA 2 epitopes or mimic molecules are shown herein to be active anti-tumour proliferative compounds and immune enhancing. For use in this regard, the compounds of the invention are administered to mammals, including humans, in an effective amount of 0.05 to 5 gms per day per kilogram of body weight. The amount depends, of course, on the condition to be treated, the severity of the condition, the route of administration of the drug, and the nature of the subject. The drugs may be administered IV, orally, parenterally, or by other standard administration routes including targeting with liposomes/RBC.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0028] FIG. 1 is a plot of animal weight vs. time in a toxicity study of compounds according to the present invention.
[0029] FIG. 2 is a plot of relative tumor volume vs days in a test of the effect anti-serum to snake venom on tumour growth retardation.
[0030] FIG. 3A is a plot of MTT uptake vs. dilution of antiserum in an in vitro screening of an affinity purified anti-serum to snake venom preparation against human colorectal tumour C170HM2 tumour cell line.
[0031] FIG. 3B is a plot of MTT uptake vs. dilution of antiserum in an in vitro screening of an affinity purified anti-serum to snake venom preparation against human bladder tumour T24 tumour cell line.
[0032] FIG. 3C is a plot of MTT uptake vs. dilution of antiserum in an in vitro screening of an affinity purified anti-serum to snake venom preparation against human lymphoma tumour MOLT 4 tumour cell line.
[0033] FIG. 3D is a plot of MTT uptake vs. dilution of antiserum in an in vitro screening of an affinity purified anti-serum to snake venom preparation against human pancreatic tumour PAH 1 tumour cell line.
[0034] FIG. 3E is a plot of MTT uptake vs. dilution of antiserum in an in vitro screening of an affinity purified anti-serum to snake venom preparation against human breast tumour MDA 468 tumour cell line.
[0035] FIG. 3F is a plot of MTT uptake vs. dilution of antiserum in an in vitro screening of an affinity purified anti-serum to snake venom preparation against human small cell lung tumour 841 tumour cell line.
[0036] FIG. 3G is a plot of MTT uptake vs. dilution of antiserum in an in vitro screening of an affinity purified anti-serum to snake venom preparation against human gastric ST24 tumour cell line.
[0037] FIG. 3H is a plot of MTT uptake vs. dilution of antiserum in an in vitro screening of an affinity purified anti-serum to snake venom preparation against human ovarian OVCAR3 tumour cell line.
[0038] FIG. 4 is a plot of mean tumour cross-sectional area vs. time in an experiment testing the effect of affinity purified anti-serum to snake venom on the mean cross-sectional area of C170HM2 in nude mice.
[0039] FIG. 5 is a plot of tumour weights in the experiment testing the effect of affinity purified anti-serum to snake venom on the mean cross-sectional area of C170HM2 in nude mice.
[0040] FIG. 6A is a plot of MTT uptake vs. dilution of antiserum in an in vitro screening of an affinity purified anti-serum to snake venom preparation in combination with a phospholipase C inhibitor 1-oleoyl-2-acetyl-sn-glycerol (OAG) against human breast tumour MDA 468 tumour cell line.
[0041] FIG. 6B is a plot of MTT uptake vs. dilution of antiserum in an in vitro screening of an affinity purified anti-serum to snake venom preparation in combination with a phospholipase C inhibitor 1-oleoyl-2-acetyl-sn-glycerol (OAG) against human small cell lung tumour 841 tumour cell line.
[0042] FIG. 6C is a plot of MTT uptake vs. dilution of antiserum in an in vitro screening of an affinity purified anti-serum to snake venom preparation in combination with a phospholipase C inhibitor 1-oleoyl-2-acetyl-sn-glycerol (OAG) against human renal TK-10 tumour cell line.
[0043] FIG. 7 is a plot of tumour cross-sectional area vs. time in an experiment testing the effect of affinity purified anti-serum to snake venom in combination with the Phospholipase C inhibitor (OAG) on the mean cross-sectional area of MDA 468 in Scid mice.
DETAILED DESCRIPTION OF THE INVENTION
[0044] The therapeutic activity of the compounds of this invention are demonstrated by inhibition of the tumour cell lines in-vitro and in-vivo. The compounds were tested for toxicity in Scid mice. Results as in FIG. 1 [toxicity data].
[0000] Toxicity Study
[0000] Method
[0045] Female Scid mice (6-8 weeks of age) were treated with either a Neat or a 1:10 dilution of the anti-serum preparation, subcutaneously (0.1 ml, daily) for a period of 14 days. The weights of the mice were measured daily. At termination, organs were removed and fixed in formalin for histological examination.
[0000] Results
[0046] No toxicity, as assessed by animal weights and clinical well-being, was evident ( FIG. 1 ).
[0047] The compounds of this invention may be combined with other known anti-inflammatory/immunosuppressive or chemotherapeutic agents such as steroids or non-steroidal anti-inflammatory agents in the pharmaceutical compositions and methods described herein.
[0048] Anti-serum to snake and/or insect venoms and/or mammalian and/or PLA 2 enzyme or its epitopes can be used as a therapeutic treatment in diseases where elevated levels of Phospholipase A 2 are evident, (e.g. Rheumatoid Arthritis, see Table B). It is also envisaged that this novel therapy with anti-serum to venom PLA 2 (snake or insect) and/or to PLA 2 components (derived from animal or plant) can be applied as a prophylactic therapy by using sub-lethal doses of venoms or the venom PLA 2 enzyme extracts together with mammalian or plant PLA 2 or synthetic peptides demonstrating PLA 2 activity plus adjuvant to stimulate an immunoglobulin response within the patient, see results—Vaccine Efficacy in Balb/c mice. It is also envisaged that a synthetic peptide incorporating the Phospholipase A 2 and/or Phospholipase C activity could be used to generate said anti-serum or therapeutic agent or vaccine. Use may also be made in the generating of this therapeutic vaccine/anti-serum by using the known sequence homology that exists between human Phospholipase A 2 and snake/insect venoms together with animal PLA 2 used in combination with compounds known to inhibit Phospholipase C activity or anti-serum developed to this enzyme.
[0049] Sustained or directed release compositions can be formulated, e.g. liposomes or those wherein the active compound is protected with differentially degradable coatings, e.g. by microencapsulation, multiple coatings, etc. It is also possible to freeze-dry the new compounds and use the lyophilizates obtained, for example, for the preparation of products for storage and subsequent injection.
[0000] Experimentation
[0050] The compounds of this invention can be identified as anti-serum to snake or insect venoms mammalian or plant PLA 2 or parts thereof or Phospholipase C or mimic molecules generated to venoms or mammalian PLA 2 molecules and/or Phospholipase C or parts thereof also the pharmaceutical use of venoms or parts thereof and/or mammalian PLA 2 or enzyme components as vaccine antigen are incorporated. Non-toxic compounds showing anti-phospholipase C activity can be incorporated with the anti-serum to PLA 2 of any origin, or mimic molecules demonstrating Phospholipase A 2 activity.
[0051] In certain applications of this therapy it may be necessary to curtail the ADCC reaction which could cause serum sickness and to ensure that this does not occur the IgG (FC) component is enzymatically cleaved from the affinity purified immunoglobulin so that natural killer cells will not react to the immunoglobulin in the anti-serum.
[0000] Ability of Anti-Serum to Snake Venom to Inhibit Phospholipase A 2 Enzyme Isolated from Human Synovial Fluid (Table A2).
[0052] The inhibition of Phospholipase A 2 enzyme from synovial fluid isolated from a patient with Rheumatoid Arthritis was tested with a range of dilutions of anti-serum to snake venom. Anti-serum to snake venom generated in horse, reconstituted in 10 ml sterile water. The following dilutions were used 1:10, 1:20, 1:40 and 1:60. The method used was as outlined in “Infection and Immunity, September 1992, p. 3928-3931. Induction of Circulating Group II Phospholipase A 2 Expression in Adults with Malaria.
TABLE A2 Results Dilution Inhibition 1:10 63% 1:20 50% 1:40 35% 1:60 29%
In-Vitro Testing of Un-Affinity Purified Snake Venom.
[0053] A range of tumour cell lines were tested with 3 concentrations of the anti-serum to snake venom by the MTT Assay. This anti-serum was not affinity purified. MTT Assay described by Alley et al, (Cancer Research, 48: 589-601, 1988) See Table B.
TABLE B SUMMARY OF RESULTS Dilution % of Control Molt 4: Human T cell Lymphoma Cancer Serum-containing Neat 48.1 1:10 53.7 1:20 40.8 Serum-Free Neat 58.7 1:10 51.2 1:20 40.6 MDA 468: Human Breast Cancer Serum-containing Neat 8.0 1:10 53.7 1:20 58.9 Serum-Free Neat 15.4 1:10 48.4 1:20 58.9 C17OHM2: Human Colon Cancer Serum-containing Neat 9.3 1:10 61.4 1:20 55.6 Serum-Free Neat 15.2 1:10 47.3 1:20 49.5 Pan 1: Human Pancreatic Cancer Serum-Containing Neat 9.3 1:10 47.5 1:20 49.2 Serum-Free Neat 43.1 1:10 53.2 1:20 69.4 841: Human small cell lung cancer Serum-containing Neat 25.2 1:10 45.5 1:20 51.1 Serum-Free Neat 63.4 1:10 60.1 1:20 59.8 T24: Human Bladder Cancer Serum-containing Neat 68.5 1:10 75.1 1:20 76.2 Serum-Free Neat 84.1 1:10 87.9 1:20 88.4
Testing Un-Affinity Purified Anti-Serum to Snake Venom Against B16F1 Melanoma Cell Line.
Mice
C57BL/6
Procedure
[0054] The mice were inoculated with 0.5×10 6 B16 F1 melanoma cells subcutaneously (sc) into flank region. Once palpable tumours had developed the mice received daily sc injections as follows: —
number of mice A Sterile water 100 μl 6 B anti-serum (full strength) 100 μl 6 C anti-serum (diluted 1:10) 100 μl 6
The dimensions of the tumours were taken daily using callipers. Once the tumours of the control mice were approximately 1.5 cm or larger in diameter all mice were killed. The tumours were removed and weighed.
Results
[0055] Small tumours were first discernible by palpitation in all mice 6-7 days after inoculation. The changes in volume as measured by callipers, together with tumour weights at autopsy. See FIG. 2 [Effect of un-affinity purified anti-serum to snake venom on Melanoma B16F1 Growth] for effect of anti-serum to snake venom on tumour growth retardation.
[0056] In-Vitro Screening of the Affinity Purified Anti-Serum to Snake Venom Preparation Against a Range of Tumour Cell Lines (Illustrated in FIG. 3A [Human Colorectal Tumour C170HM2], FIG. 3B [Human Bladder Tumour T24], FIG. 3C [Human Lymphoma Tumour MOLT 4], FIG. 3D [Human Pancreatic Tumour PAN 1], FIG. 3E [Human Breast Tumour MDA 468], FIG. 3F [Human Small Cell Lung Tumour 841], FIG. 3G [Human Gastric ST24], and FIG. 3H [Human Ovarian OVCAR3])
[0000] Introduction
[0057] The in-vitro inhibitory effects of the horse generated anti-serum to snake venom preparation, previously evaluated were obscured due to serum enhancement of tumour cell growth. Thus in the following assay, affinity purified anti-serum to snake venom was evaluated.
[0000] Method
[0058] The cell lines were seeded into 96 well plates at a cell concentration of 10 4 cells per well in both serum free (Hams F12:RPMI 1640+0.5% bovine serum albumen) and serum-containing medium (RPMI 1640+10% heat inactivated foetal calf serum). The anti-serum preparation was diluted in the corresponding medium and added to the wells, 2-3 hours after the cells (to allow for cell adherence). The plates were incubated at 37° C. in −5% CO 2 for 3 days. The cells were then incubated with 1 mg/ml MTT (methyl thiazol tetrazolium) for 4 hours at 37° C. The crystals were then solubilised with dimethyl sulphoxide and the absorbance measured at 550 nm.
[0000] Results
[0059] The test anti-sera inhibited all of the cell lines at all concentrations examined. The level of inhibition was statistically significant from the untreated control at all anti-serum dilutions, with all cell lines as assessed by a one way analysis of variance.
[0060] In-Vivo Test
[0061] The Effects of Affinity Purified Anti-Serum to Snake Venom on Human Colorectal C170HM 2 Cell Line.
[0000] Materials and Methods
[0062] C170 MH 2 cells were injected subcutaneously into the left flank of ten male nude mice. The mice were allocated randomly to two groups.
[0063] Group 1-100 μl anti-serum twice daily intravenously (IV)
[0064] Group 2-100 μl PBS twice daily IV
[0000] Tumours were measured twice weekly, using callipers, in two dimensions. Cross-sectional areas were calculated. The mice were also weighed once weekly. The therapy was terminated at day 22.
[0000] Results
[0065] The cross-sectional areas were measured at increasing time points during the experiment, as shown in FIG. 4 [Effect of affinity purified anti-serum to snake venom on the mean cross-sectional area of C170HM2 in nude mice]. The affinity purified anti-serum preparation induced a slowing in growth when compared to saline controls. An ANOVA was performed on the results in which the treatment was evaluated with respect to time, and shows a significance of P=0.028.
[0066] At the termination of the experiment, the tumours were weighed and the results are shown in FIG. 5 [Effect of affinity purified anti-serum to snake venom on the final tumour weight of C170HM2]. No toxic effect of the affinity purified anti-serum preparation was observed.
[0000] In-Vitro Screen of the Affinity Purified Anti-Serum to Snake Venom Preparation in Combination with a Phospholipase C Inhibitor 1-oleoyl-2-acetyl-sn-glycerol (OAG) 5 μMolar, on a Range of Cancer Cell Lines.
[0000] Methods
[0067] The affinity purified anti-serum to snake venom preparation was diluted 1:2 and 1:10 and was combined with 5 μmolar OAG and added to the wells as previously described for the MTT Assay. The cell lines tested were Human Breast tumour, MDA 468, Human small cell lung tumour 841 and Human renal TK-10. Results as shown in FIG. 6A [Affinity purified anti-serum to snake venom and (OAG) a Phospholipase C inhibitor combination—Human breast tumour MDA 468], FIG. 6B [Affinity purified anti-serum to snake venom and (OAG) a phospholipase C inhibitor combination—Human small cell lung tumour 841] and 6 C [Affinity purified anti-serum to snake venom and (OAG) a phospholipase C inhibitor combination—Human renal TK-10].
[0000] In-Vivo Testing of the Combination of Affinity Purified Anti-Serum to Snake Venom and 1-oleoyl-2-acetyl-sn-glyceral (OAG) at 5 μm Concentration on the Growth of MDA 468 Cell Line.
[0000] Method
[0068] MDA 468 tumours were aseptically removed from donor female Scid mice. The tissue was aseptically minced, pooled and implanted into anesthetized female Scid mice (anaesthetic comprised of a 0.2 ml injection of Hypnorm (Jannsen):Hyonovel (Roche):distilled water in a 1:1:5 ratio). Tissue implants consisted of 3-5 mm 2 pieces and after subcutaneous transplantation into the left flank, the incision was clipped. The Scid mice were then randomised into 2 groups of 10 animals. They were treated daily with a 0.2 ml subcutaneous injection (in the opposite flank to the tumour graft) of a combination of affinity purified anti-serum to snake venom and 5 μm molar of (OAG) dilution of the anti-serum preparation. The control animals received 0.2 ml phosphate buffered saline, pH 7.6. All animals were terminated on day 63, and the tumours were dissected out, weighed and processed for histology. Results are in FIG. 7 [Effect of the affinity purified anti-serum to venom in combination with the Phospholipase C inhibitor (OAG) 5 μm].
[0000] Vaccine Efficacy in Balb/c Mice after Challenge with WEHI-3 Cell.
[0069] The objective of study is to demonstrate the efficacy of sub-lethal levels of Russelli vipera venom entrapped in liposomes and porcine phospholipase A 2 enzyme entrapped in liposomes working in combination to confer a sustained and protective antibody response to a challenge by Leukaemia cells (WEHI-3 cells)
[0070] The Russelli vipera venom was toxoided with 2% osmium tetroxide and entrapped in liposomes (egg phosphocholine and cholesterol). The liposomes were sterilised.
[0071] The Porcine Phospholipase A 2 enzyme was entrapped in liposomes (egg phosphocholine, and cholesterol) and were sterilised.
[0072] Immunisation of mice consisted of an initial subcutaneous injection of 0.25 mls (containing 250 μg of venom) and 3 days later the mice were injected subcutaneously with 0.25 mls of porcine PLA 2 (containing 250 μg of porcine PLA 2 . Boosters of each vaccine were given at 3 week intervals.
[0073] Control mice were injected with 0.25 mls of sterile physiological saline on days corresponding to test mice inoculations.
[0000] Animals
[0074] Balb/c mice (20-25 g) were used in the study. 15 mice were used in each group.
[0075] Group I—test mice
[0076] Group II—control mice
[0000] Challenge
[0077] The immunised mice and controls were challenged by intravenous injection into tail vein with approximately 5×10 5 leukemic cells (WEHI-3 cells) on day 30 of study.
[0078] Test mice are observed for extended life span after the death of the control mice after approximately 24 days.
[0000] Results Obtained
[0079] All control mice died of leukaemia within the allotted time span of 24 days. The venoid combination inoculation protected the vaccinated group from the cancer cell challenge and there was a 100% survival rate at day 35 when the experiment was terminated.
[0080] Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilise the present invention to its fullest extent. The preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the disclosure in any way whatsoever.
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A method of treating a mammal prophylactically to prevent neoplastic development comprises administering to the mammal a therapeutic vaccine comprising venom and at least one adjuvant. The method optionally further comprises administering to the mammal at least one other therapeutically effective agent, e.g., an anti-inflammatory agent.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related generally to combustion processes and, more particularly, is directed towards a method and apparatus for synergistically reducing pollutant emissions while simultaneously increasing the efficiency of combustion. Even more particularly, the present invention is directed towards a method for enhancing the production of NO+ during combustion, and for separating, removing and extracting same for later processing into a valuable product.
2. Description of the Prior Art
Today, nitrogenous fertilizer is mainly derived from ammonia synthesized in the Haber-Bosch process from methane gas. In fact, in 1974, nearly 15% of all methane consumed in the United States went for the production of nitrogenous fertilizer. By the year 2000, it is estimated that five times as much fertilizer will be required, but the source of such fertilizer is not yet resolved.
Nitrogenous fertilizer is naturally formed in large quantities during an electrical lightning storm as a result of the formation of significant quantities of nitrogen oxides, NO x , which are in turn formed whenever the temperature of air is raised substantially. Man-made electric arcs have also been used to produce NO x , but this technique has been discarded in favor of others which require less energy.
NO x is also quite readily formed during high temperature combustion involving fossil fuels and air. NO x formation by this technique has heretofore been recognized as being potentially quite useful, as, for example, a feedstock for nitrogenous fertilizer. See, for example, the following articles:
"Japan's NO x Cleanup Routes", Ushio, S., Chemical Engineering, July 21, 1975, pp. 70, 71;
"Bottoming - Cycle Engines", Lindsley, E.F., Popular Science, January, 1976, pp. 82 - 85, 130 - 132;
"NO x Abatement for Stationary Sources in Japan", Ando, J., Tohata, H., and Isaacs, G.A., Environmental Protection Agency, Office of Research & Development, EPA-600/2-013b, January, 1976; and
"SO 2 and NO x Removal Technology in Japan -- 1976", Ando, J. Environmental Technical Information Center, Japan Management Association, 3-1-22 Shiba Park, Minato-ku, Tokyo, Japan, February, 1976.
However, to the best of my knowledge, no practical, effective technique has yet been proposed for capturing the NO x formed from a combustion process.
Moreover, since NO x itself is notoriously toxic and is well recognized as a severe pollutant, efforts are presently directed towards either preventing the formation of NO x during combustion processes, or towards removing same once formed. The former technique, known in the art as combustion modification, attempts to inhibit the formation of NO x by operating at reduced combustion temperatures with fuel-air mixtures that are as air-lean as possible. Unfortunately, operating under such conditions inevitably results in a lower energy conversion efficiency which, in turn, wastefully increases fuel consumption.
The second technique mentioned above is known in the art as flue gas treatment wherein NO x is removed from the cooled flue gas, after it has already been formed, by either catalytic reduction to nitrogen and oxygen or by absorption in a suitable material. These types of controls, while somewhat effective, are unfortunately quite expensive to operate and maintain, since either an expensive catalyst must be replenished, or the sludge resulting from absorption must be disposed of in an environmentally acceptable manner.
While flue gas treatment controls are generally utilized in conjunction with some form of combustion modification program, present day controls for NO x rely chiefly upon inhibiting the formation of NO x . This is believed due to the fact that once NO x is formed, it is practically indestructable, i.e., no known process can, by itself, adequately reduce or capture the NO x before it is emitted into the ambient atmosphere.
It therefore may be appreciated from the foregoing that a technique which not only reduces NO x pollutant emissions, but increases combustion efficiency while also providing a ready source of NO x for later transformation into a useful product, would be extremly valuable. In other words, if the NO x emitted with the stack or exhaust gases from a combustion process could be effectively collected, its role would be reversed from that of a noxious pollutant to that of a valuable resource, for example, as a feedstock for the production of nitrogenous fertilizer.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to increase the energy conversion efficiency of combustion processes while simultaneously reducing pollutant emissions by economically and effectively separating, collecting and converting such emissions into valuable resources.
A further object of the present invention is to provide a method and apparatus for reducing pollutant emissions while increasing the efficiency of combustion which takes advantage of a naturally occurring phenomenon within the combustion zone.
Another object of the present invention is to provide a combustion process which reduces fuel consumption, reduces pollutant emissions, leads to the formation of useful and valuable products, and does so economically and efficiently.
Another and further object of the present invention is to provide a technique for reducing the emission of pollutants, including NO x , into the atmosphere from a combustion process, while simultaneously increasing the efficiency of combustion.
A further object of the present invention is to provide a technique for producing NO x in large quantities which may be later processed into a valuable resource such as nitrogenous fertilizer.
A still further object of the present invention is to provide a technique which facilitates separation, removal and collection of NO x by enhancing the formation thereof during the combustion process.
A still further object of the present invention is to provide a technique for producing NO x in sufficient quantities to meet anticipated demands for nitrogenous fertilizer.
A still further object is to increase rather than reduce the formation of NO x in a combustion process and then recover it in an economically possible manner, with means for reducing the usual polluting effect on the environment by NO x , and accomplishing this by increasing, rather than decreasing, the efficiency of the combustion process.
The foregoing and other objects are attained in accordance with one aspect of the present invention through the provision of a method for reducing pollutant emissions from the gaseous products of a combustion flame, which comprises the step of separating the pollutant emissions from the gaseous product of combustion at the combustion zone of the flame. The pollutant emissions are separated by extracting ionized matter from the gaseous products of combustion at the combustion zone. Aperture means may be provided in or through the sidewall of the combustion chamber adjacent the combustion zone through which the ionized matter may then be extracted. The positive ions of the products of combustion may be attracted to a negatively charged electrode positioned adjacent the aperture means which serves to establish a small electric field across the combustion zone. A collector means may be positioned adjacent the aperture means for collecting the positively charged species for later processing. The electric field is preferably on the order of a few to hundreds of volts per centimeter.
In accordance with yet other aspects of the present invention, apparatus is provided for reducing pollutant emissions from gaseous products of combustion, which comprises means positioned at the combustion zone for separating the pollutant emissions from the gaseous products of combustion. The separating means more particularly comprises means for establishing an electric field at the combustion zone. Means may also be provided for collecting the pollutant emissions once separated from the gaseous products of combustion, the collecting means including aperture means formed in the sidewall of the combustion chamber at the combustion zone. An electrode connected to a negative source of electrical potential may be connected to the collecting means such that the latter serves as the attractive force for the positively charged matter. Preferably, the combustion burner is connected to a source of positive electrical potential and is located upstream of said aperture means.
In accordance with yet other aspects of the present invention, a method is provided for increasing the energy conversion efficiency of a fuel during its combustion while simultaneously reducing pollutant emissions resulting from such combustion, which comprises the steps of combusting the fuel at higher than normal temperatures to produce a hot combustion gas, and extracting pollutant emissions from the hot combustion gas near the combustion zone of the combusting mixture. The high temperature enhances the production of ionized species, the positive ions of which are attracted to a negative source of electrical potential positioned adjacent the combustion zone. The separation of the positive ions is achieved by applying an electrostatic field across the combustion zone which is preferably on the order of a few to hundreds of volts per centimeter.
The present invention, in accordance with other aspects, contemplates a method of producing NO x which comprises the step of combusting a fuel to produce a main hot gas stream, and separating NO x from the main gas stream at the combustion zone of the fuel-oxidizer mixture. The method further contemplates the steps of collecting the separated NO x at the combustion zone, and enhancing the formation of NO x by combusting the fuel at above-normal combustion temperatures.
BRIEF DESCRIPTION OF THE DRAWINGS
Various objects, features and attendant advantages of the present invention will be more fully appreciated as the same become better understood from the following detailed description thereof when considered in connection with the accompanying drawings, in which:
FIG. 1 is a schematic representation of an experimental setup constructed and operated to verify the principles of the present invention;
FIGS. 2 and 3 are graphs which illustrate experimental results achieved with the apparatus of FIG. 1; and
FIG. 4 is a schematic representation of the components which comprise a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
At the elevated temperatures encountered during combustion of fossil fuels, the energy level of the combusting mixture is sufficiently high such that many of the species found in the combustion gases will be ionized to various degrees. The dominant charged species found in the combustion zone are the ions NO + , H 3 O + , CHO + , and free electrons. Each of the ionized molecules has a relatively low ionization potential. For example, NO + has an ionization potential of 9.25 ev. The present invention takes advantage of these low ionization potentials by establishing an electrostatic field at the combustion zone. The electrostatic field acts to separate and collect such positively charged ions before they have been neutralized and had an opportunity to be released to the atmosphere as noxious pollutants; e.g., NO.
Referring now to FIG. 1, the drawing schematically illustrates an experimental configuration utilized to verify the principles of the present invention. Reference numeral 10 connotes the general outline of a flame body issuing from a burner 11. The burner 11 is positioned in the mouth 13 of an elongated combustion chamber 12.
The combustion zone of the flame 10 is indicated generally by reference numeral 20. Located in the sidewall of combustion chamber 12 at a position substantially adjacent the combustion zone 20 are a pair of electrodes 26 and 28 which are connected, via lead lines 42 and 40, respectively, to a D.C. power supply 30. Lead 40 is connected to a positive source of potential, such that electrode 28 serves as an anode, while lead 42 is connected to a negative source of potential such that electrode 26 serves as a cathode. The anode 28 and cathode 26 are located near the apertures 24 and 22 in combustion chamber 12 so as to establish an electrostatic field at the combustion zone 20 of the burner 11.
In operation, the positive ions and electrons created during the combustion process will be respectively attracted towards the cathode 26 and anode 28. Thus, during combustion, if a collector is placed adjacent aperture 22, a mixture rich in NO + and other positive ions will be extracted from the main combustion gases as they pass through the combustion chamber 12. In this manner, the percentage of NO emitted into the atmosphere may be substantially reduced.
Although it is known that ionization occurs at elevated temperatures of combustion, it has been discovered that actual ion concentrations in combustion mixtures are several orders of magnitude higher than predicted assuming thermochemical equilibrium. While the precise nonequilibrium mechanism for explaining such a result has not yet been established, it is believed that chemi-ionization phenomena are responsible. Within the context of the present invention, electric fields as low as one to two volts per centimeter have been found to significantly reduce NO x emissions.
Experiments have been performed using the equipment components illustrated in FIG. 1 for verifying that NO x may indeed be extracted from the products of combustion at the combustion zone. One end of a flue 14 was placed in communication with the outlet end 15 of combustion chamber 12. The flue 14 was bent at an approximate 30° angle so as to provide a uniform mixture of the exhaust gases and sufficient cooling in order to enable the measurement procedure to be carried out. An additional glass tube 16 was used to further cool the exhaust gases issuing from opening 17 of flue 14.
Reference numeral 18 indicates schematically a measuring tube inserted in the open end of glass tube 16. Measuring tube 18 is part of a conventional set of detector tubes utilized with a gas concentration detecting instrument, such as, for example, a National/Drager Multi-Gas Detector. Such a machine provides a readout of the parts per million (ppm) of NO x issuing from the open end of tube 16.
A D.C. power supply 30 was used to establish the electrostatic field across the openings 22 and 24 in the sidewall of combustion chamber 12. The chamber 12 itself consisted of a ceramic cylinder, approximately one-half meter long, with an outside diameter of about 10 centimeters. The distance between cathode 26 and anode 28 was about 15-20 centimeters.
The tests were conducted with two different burners 11, one being a welder's oxy-acetylene torch, the other being a propane torch. The current emitted by power supply 30 was monitored via an ammeter 34, while its voltage output was indicated by a voltmeter 32.
FIGS. 2 and 3 are graphs which plot the detected concentration of NO x vs. the applied voltage for the oxy-acetylene and propane-air torches, respectively. In general, with the electrostatic field applied across the combustion zone (i.e., normal to the mean mass flow in the flame), the concentration of NO x was reduced from that without the electric field by as much as 21/2 to 5 times. For maximum extraction, the electric field strengths were as low as five to seven volts per centimeter for the oxy-acetylene flames, and fifty to sixty volts per centimeter for the propane-air flames.
Referring more particularly to FIG. 2, it may be seen that with an applied voltage as low as 100 volts, more than 75% of the NO and NO 2 mixture was removed from the combustion gases.
FIG. 3 indicates that the minimum applied voltage necessary to obtain the maximum reduction of NO and NO 2 in the flue gas was about 800 to 900 volts.
It may be appreciated from comparing FIGS. 2 and 3 that the experiments conducted with the oxy-acetylene torches produced about 25 to 50 times as much NO and NO 2 as produced by the propane and air torches. This is believed primarily due to the much higher combustion temperatures of the oxy-acetylene flames (800°-1100° K. hotter than propane-air flames).
Additional experiments were performed to confirm the collection capabilities of the present invention with the apparatus schematically illustrated in FIG. 4, to which attention is now directed. The components again include a combustion chamber 12 having a pair of apertures 22 and 24 formed in the sidewalls thereof. A pair of cylindrical collector tubes 36 were positioned adjacent the apertures 22 and 24 so as to be in fluid communication with the combustion zone 20. Further, the tubes 36 were electrically connected to one another as well as to a source of negative potential so as to act as collectors of positively charged species. The centers of the apertures 22 and 24 were positioned approximately 141/2 centimeters above the tip of torch 44. The torch 44 was itself connected as the positive electrode.
With an oxy-acetylene torch utilized as the burner 44, and an applied electric field of about 25 volts per centimeter, a 14-fold increase was achieved in collecting the NO x in tubes 36 compared to the amount of NO x present in the tubes without the applied electric field.
While the details of construction of ion collection chambers with respect to each burner's combustion zone may require individual custom design features, the best mode of the present invention presently contemplates placement of the positive electrode(s) in the vicinity of the burners, fuel injectors, or flame holders, and placement of the negative electrode(s) (electrically separated from the combustion chamber), in and/or near the collection chambers. The outlets of tubes 36 may, of course, be manifolded to a common collector prior to subsequent processing. The collected mixture will, of course, consist of several different previously ionic, now neutralized, species quite highly concentrated within a relatively small amount of flue gas. The separation of the various substances may be accomplished from known chemical processes. In processing the NO x , for example, it may first be passed through an oxidizing catalyst to convert the NO to NO 2 , or through another oxidizing catalyst to form nitric acid by the reaction:
2NO.sub.x + H.sub.2 O + (2.5-x)O.sub.2 → 2HNO.sub.3.
it may be appreciated from the foregoing that the techniques of the present invention differ significantly from prior art pollution controls for combustion processes in that, by virtue of the present invention, NO may be encouraged to form by operating at higher temperatures which may more closely approach stochiometric adiabatic equilibrium temperatures. This, in turn, increases the energy conversion efficiency of the combustion process. NO is effectively and economically separated from the main flue gas stream in the combustion zone by means of a relatively low magnitude electric field to therefore prevent pollution of the environment. The separated NO may be easily collected to be further processed as, for example, a feedstock for nitrogenous fertilizer production.
While the viability of the techniques of the present invention have been specifically described hereinabove within the context of several experimental situations, it will be clear to those skilled in the art that the principles may be easily extended to common combustion environments, such as those occuring in boilers, furnaces, gas turbines, internal combustion engines, and the like.
Further, while the above discussion has centered around the useful separation, removal and collection of the oxides of nitrogen (NO x ) it will be apparent to those skilled in the art that other combustion generated pollutants, such as sulfur oxides SO x , carbon monoxide CO, and the unburnt and partially burnt hydrocarbons will also be influenced in a beneficial manner. For example, at the higher recommended combustion temperatures, more complete combustion results in a more complete conversion of harmful CO to benign carbon dioxide and water. Further, since the energy conversion efficiency is higher, less fuel is used, and less thermal waste is emitted. Other pollutants extracted may also prove susceptible to subsequent treatment and use.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
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A method and apparatus for reducing pollutant emissions from a source of combustion while simultaneously increasing the combustion efficiency. In a preferred mode, the technique contemplates the separation, removal and collection of positively charged species at the combustion zone. This is achieved by applying a relatively small magnitude electrostatic field at the combustion zone via positive and negative electrode means. A negative electrode may be positioned adjacent aperture means formed in the sidewall of the combustion chamber at the combustion zone so as to attract positive ionic species that include the pollutant emissions (e.g., NO + ) desired to be extracted. A negative electrode may also be electrically connected to a tube that serves to collect the pollutant for later processing to a useful by-product (e.g., nitrogenous fertilizer). Effective removal of the ionic species at the combustion zone permits combustion to occur at higher temperatures which, in turn, results in greater combustion efficiency.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to electrical ground rod driving devices, and more specifically to apparatus of improved construction so as to be capable of performing its intended use with a user thereof standing, at all times during said use, at local earth level adjacent said electrical ground rod, said apparatus being further intended to drive said electrical ground rod completely into the earth without resort to the use of sledges or hammers.
2. Description of the Prior Art
Ground rods for electrical service are usually required by construction codes and accepted practice to be at least ten feet (greater than 3.0 meters) in length, and driven substantially vertically into the earth for their entire length. It has often, heretofore, been common practice to provide a laborer with a ladder and a sledge hammer, the laborer ascending the ladder to a height sufficient to enable striking the top end of a vertically held electrical ground rod with the sledge hammer, the laborer descending the ladder appropriately as the electrical ground rod is driven into the earth so as to readily repeat striking the top end of the electrical ground rod with the sledge hammer. This approach, while usually employed for its simplicity and minimal tool requirements, is accompanied by significant risks in that the ladder may become unstable from variations in terrain level and softness of the earth. Also, it often arises that the sledge does not squarely strike the top end of the electrical ground rod, producing strain on the laborer to retain control of the sledge hammer during such glancing blows. Moreover, it is not unusual for the sledge hammer to be dropped during such a glancing blow, creating a hazard to other persons proximate to the situs of the electrical ground rod.
Several inventions are present in the prior art which provide apparatus useful in assisting in driving posts and rods. Such devices range from simple manually operable weights vertically drivable onto attachments coupled to the posts or rods, to adaptations of devices commonly known as pile drivers. As examples of simple mechanical devices, reference is made to U.S. Pat. Nos. 2,690,055; 2,693,086; 2,802,340, 2,998,087; 3,115,199; 4,448,264; and 4,971,479. More complex devices are illustrated by U.S. Pat. Nos. 3,073,571; 3,499,497; and 3,827,509.
In U.S. Pat. No. 2,690,055, issued 09/28/54 to LUNDGREN, et.al. for "Post Driving Device," an annular cylindrical element, having most of its mass at a lower end, is placed around the post. Using the external handles provided, the element is manually vertically raised and then brought forcefully downwardly against a bracket relocatably affixed to the post being driven. In U.S. Pat. No. 2,693,086, issued 11/02/54 to CARUTHERS, et.al. for "Ground Rod Driver," an elongated hollow tube is configured to fit around the rod. A lower weighted end of the rod slides over a threaded collet type attachment relocatably coupled to the ground rod. The tube impacts vertically downwardly upon a shoulder of the collet under manual manipulation of the elongated tube. The patent to TALLMAN, issued as U.S. Pat. No. 2,802,340 on 08/13/57 for "Ground Rod Driver," is almost identical to the device of CARUTHERS, et.al., with TALLMAN being one of the co-inventors of the earlier patent. U.S. Pat. No. 2,998,087, issued 08/29/61 to IDDINGS for "Fence Post Driver," also uses an elongated tube, this tube having a weighted closure at its upper end, which is manually vertically drawn downwardly so that the weight strikes the upper end of the post being driven. Earlike handles are provided for ease of use of this device.
In U.S. Pat. No. 3,115,199, issued 12/24/63 to LINABERY for "Post Driving Device," a short section of tubing, having a weighted plug at an upper end thereof, is provide with extended downwardly directed handles to enable manually drawing the tube downwardly onto the top of the post being driven. The extent of the handles allows the user to stand on the ground surface while using this device. However, the length of the handles appears to limit the depth to which the upper end of the rod may be driven. Another elongated tube device is described in U.S. Pat. No. 4,448,264, issued 05/15/84 to PEYTON for "Ground Rod Driving Pole." This device includes a number of spring-loaded pins passing transversely through the tube, each generally horizontally, in a spaced apart arrangement longitudinally along the extent of the tube. The pins are first retracted to ride along an exterior surface of a ground rod inserted into the tube, except for the uppermost pin. As the tube is manually raised and lowered, the upper transverse pin strikes the upper end of the ground rod until the raising of the tube between downward strokes enables the next lower transverse pin to pass over the upper end of the ground rod, this pin then becoming the driving impact pin. Each such transverse pin sequentially is allowed to pass over the top end of the ground rod.
For posts having pre-formed transverse holes, a relocatable bracket engaging a selected hole through the post is taught by BYERS, Sr., et.al. in U.S. Pat. No. 4,971,479, issued 11/20/90 for "Post Driver," to serve as an impact surface for an annular weight element drawn downwardly thereon. The weight may be placed below the bracket, before attachment of the bracket, to assist in removing the post.
A small version of a hydraulic pile driver is described in U.S. Pat. No. 3,073,571, issued 01/15/63 to WUNSCH for "Tractor Mounted Metal Post Driver." Pneumatic Jack hammers engage with brackets affixed to poles in both U.S. Pat. No. 3,499,497, issued 03/10/70 to MOORE for "Sign Pole Driver," and U.S. Pat. No. 3,827,509, issued 08/06/74 to LARSON for "Floating Type Drive Spike Accessory."
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide an apparatus adapted to enable a user, standing on the earth surface adjacent a site at which an extended electrical ground rod is to be driven, to manually drive the electrical ground rod substantially vertically into the earth.
Another object of the present invention is to provide an apparatus adapted to manually accomplish driving an electrical ground rod substantially vertically into the earth wherein separate driving segments are arranged so that handling of the apparatus substantially proximate to a center of gravity thereof is facilitated.
An additional object of the present invention is to provide an apparatus adapted to accept an extension element useful in accomplishing a final stage of driving an electrical ground rod so that an uppermost end of the electrical ground rod is substantially at earth level of the surrounding earth surface.
A further object of the present invention is to provide an apparatus that is of durable construction and that is inexpensive to fabricate.
These, and other objects, advantages, and features of the present invention that may become apparent through the subsequent description and claims herein, are provided by an apparatus comprising three unequal length tubular elements and an extension element. A first tubular element, having a relatively short length, of the order of about two feet (approximately 0.6 meter), is rigidly enclosed at an upper end by a cap of a high tensile strength material, and is open at a lower end thereof. A second tubular element, having an overall length of approximately four feet (approximately 1.2 meters), is adapted to be open at both an upper and a lower end, with a plug of a high tensile strength material rigidly affixed therewithin at substantially a mid-point of its longitudinal extent. A third tubular element, having an extent of approximately five feet (approximately 1.8 meters), is open at each end thereof, and contains no internal plugs. Each of the three tubular elements is provided with an inner diameter suitable to freely and slidably accept an outer diameter of the electrical ground rod therewithin.
The apparatus of the present invention is fabricated such that when the upper ends of the first, the second, and the third tubular elements are at the same vertical elevation, and when the three tubular elements are arranged to have their longitudinal axes intersect a transverse plane at the apexes of an equilateral triangle having side lengths substantially equal to an outer diameter of each tubular element, said tubular elements are rigidly mutually coupled together along their respective mutual lengths, such as by a welding process. Accordingly, the lower ends of the three tubular elements will assume differing elevations.
An extension element is formed of a short length of tubular structure substantially identical to said three tubular elements rigidly coupled, at a first end thereof, to a cylindrical rod portion having an outer diameter substantially identical with that of an electrical ground rod and a length of approximately twenty-five inches (approximately 0.64 meters). The end of the tubular portion opposite to the end to which the rod portion is affixed remains open. The tubular portion and the rod portion of the extension element are joined such that their respective longitudinal axes are coaxial.
In use, the assembly of the three tubular elements provides the driving apparatus for vertically embedding all but about two feet of the electrical ground rod. Initially, an upper end of the electrical ground rod is inserted into the open end of the shortest of the three tubular elements of the apparatus. The electrical ground rod and the apparatus are then manually positioned to a vertical attitude with the lower end of the electrical ground rod placed at the desired point of entry into the earth surface. Using the longest of the three tubular elements as a handle, a user of the apparatus raises the apparatus relative to the electrical ground rod through a distance less than the length of the shortest tubular element and then brings the apparatus forcefully downwardly so that the cap on the end of the shortest tubular element strikes upon the upper end of the electrical ground rod, causing the electrical ground rod to be driven downwardly into the earth. Repeated vertical motions of the apparatus are then performed by the user until the lower end of the longest tubular element approaches the earth surface.
At such time, the apparatus is raised sufficiently so that the shortest tubular element is fully above the upper end of the partially driven electrical ground rod. Further vertical elevation of the apparatus is then performed such that the lower end of the intermediate length tubular element is at an elevation greater than the upper end of the partially driven electrical ground rod. The open lower end of the intermediate length tubular element is engaged over the upper end of the electrical ground rod. Again using the longest tubular element as a handle, the electrical ground rod may then be driven further by repeated vertical strokes causing the plug within the second tubular element, proximate to its longitudinal mid-point, to impact on the upper end of the electrical ground rod, driving it farther into the earth.
When further driving using the lower portion of the second tubular element would cause the lower end of the third tubular element to contact the local earth surface, the apparatus is again elevated so that the lower end of the second tubular element is at an elevation above that of the upper end of the partially driven electrical ground rod, disengaging the second tubular element from the electrical ground rod. The apparatus is then inverted and the open end of the initially upper portion of the second tubular element, now oriented to be the lower portion thereof, is engaged over the upper end of the electrical ground rod. Repeated vertical striking of the plug affixed within the second tubular element on the upper end of the electrical ground rod will cause the electrical ground rod to be driven until only about two feet (about 0.6 meters) thereof remain above the local earth surface.
Subsequently, the apparatus is again raised to disengage from the upper end of the electrical ground rod. The tubular portion of the extension element is then placed on the upper end of the electrical ground rod and the inverted lower portion of the second tubular element (initially the upper portion of the second tubular element) is placed over the rod portion of the extension element. It is to be noted that the rod portion of the extension element is longer than the length of the portion of the second tubular element into which it slides. Thus, repeated vertical manipulation of the apparatus will cause the plug within the second tubular element to strike the upper end of the rod portion of the extension element without contact between the end of the second tubular element and the tubular portion of the extension element. The lower end of the rod portion of the extension element, at the interface with the tubular portion of the extension element, impacts on the upper end of the electrical ground rod. Vertical manipulation of the apparatus is continued until the tubular portion of the extension element becomes embedded in the local earth surface, at which time the full length of the electrical ground rod has been driven substantially vertically into the earth.
It is clear that the above described embodiment may be varied and/or modified, both as to lengths of the several tubular elements, and as to their mutual arrangement, without departing from the spirit of the present invention. All such obvious variations are contemplated to be within the scope of the present invention as characterized by the claims appended hereto.
BRIEF DESCRIPTION OF THE DRAWING
In the accompanying drawing, wherein like reference numbers and symbols are utilized throughout to refer to like elements and features:
FIG. 1 illustrates a typical electrical ground rod as suggested by the prior art;
FIG. 2 presents a perspective view of an apparatus in accordance with the present invention;
FIG. 3 is a top view of a portion of the apparatus of FIG. 2, taken from a plane indicated by 3--3 of FIG. 2;
FIG. 4 provides a sequential illustration of a first stage of use of the apparatus in accordance with the present invention, with FIG. 4a showing an initial positioning of an electrical ground rod and the present apparatus, FIG. 4b showing the electrical ground rod driven substantially to the extent allowable during said first stage of use, and FIG. 4c showing removal of said apparatus upon completion of said first stage of use;
FIG. 5 provides a sequential illustration of a second stage of use of the apparatus in accordance with the present invention, with FIG. 5a showing the orientation of said apparatus in preparation for the start of said second stage of use, FIG. 5b showing an initial portion of driving during said second stage of use, FIG. 5c showing the electrical ground rod driven substantially to the extent allowable during said second stage of use, and FIG. 5d showing removal of said apparatus upon completion of said second stage of use;
FIG. 6 provides a sequential illustration of a third stage of use of the apparatus in accordance with the present invention, with FIG. 6a showing the orientation of said apparatus in preparation for the start of said third stage of use, FIG. 6b showing an initial portion of driving during said third stage of use, FIG. 6c showing the electrical ground rod driven substantially to the extent allowable during said third stage of use, and FIG. 6d showing removal of said apparatus upon completion of said third stage of use; and
FIG. 7 provides a sequential illustration of a final stage of use of the apparatus in accordance with the present invention, with FIG. 7a showing the orientation of said apparatus, including an extension element thereof, in preparation for the start of said final stage of use, FIG. 7b showing an initial portion of driving during said final stage of use, FIG. 7c showing the electrical ground rod fully driven into the earth at the completion of said final stage of use, and FIG. 7d showing said apparatus removed and said electrical ground rod fully emplaced.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, a typical electrical ground rod, as suggested by the prior art, is indicated generally at 10. In practice, the electrical ground rod 10 is generally configured as a substantially right circular cylindrical solid having a length of at least ten feet (in excess of 3.0 meters) and a diameter commensurate with providing adequate structural strength to enable said electrical ground rod to be driven longitudinally vertically into the earth for its entire length. Such electrical ground rods are formed from a material exhibiting a high degree of electrical conductivity, with copper being an example of a material of choice.
Referring next to FIG. 2, in accordance with the present invention, an apparatus for manually driving an electrical ground rod into the earth is indicated generally at 11, with an extension element thereof indicated generally at 12. The apparatus 11 is formed as a rigid assembly of a first tubular element 14, a second tubular element 16, and a third tubular element 17. Each of the tubular elements 14, 16, and 17 are formed of right circular cylindrical stock to be of identical respective inner diameters, each accepting the outer diameter of said electrical ground rod 10 longitudinally therein, with sufficient margin to enable freely longitudinally sliding the electrical ground rod 10 therein in an axial direction of said tubular elements 14, 16, or 17. The three tubular elements 14, 16, and 17 also have respectively equal annular wall thicknesses and outer diameters. As can be noted from the illustration of FIG. 2, the first tubular element 14 has the shortest length, the third tubular element 17 has the greatest length, and the second tubular element 16 has a length intermediate thereof.
While exact lengths of the three tubular elements 14, 16, and 17 are not crucial to the construction or use of the apparatus 11, as a practical matter, the first tubular element 14 should be provided with a length of substantially twenty-four inches (approximately 61 centimeters). A cap element 18, formed of a high tensile strength material, is rigidly affixed to an upper end 19 of the first tubular element 14 to enclose said upper end 19 while providing a right circular cylindrical coaxial cavity, of the aforesaid approximate length, within the annular walls of said first tubular element 14. A lower end 20 of said first tubular element 14 is to be open.
Construction of said second tubular element 16 is accomplished by rigidly assembling two segments 21 and 22 of said tubular stock, each having a length of substantially twenty-four inches (approximately 61 centimeters), with an intermediate plug element 23 so as to form an extended tubular element 16 having a length exceeding four feet (exceeding 122 centimeters) by the thickness of the plug element 23. The second tubular element 16 is therefore open at both an upper end 24 and a lower end 26 thereof, with coaxial right circular cylindical cavities extending downwardly from said upper end 24 and upwardly from said lower end 26, respectively, within said segments 21 and 22, each cavity having an internal axial length of the aforesaid approximate segment length.
Said third tubular element 17 is formed from a single segment of said tubular stock to have a length of substantially five feet (approximately 152.4 centimeters), open at both an upper end 27 thereof and at a lower end 28 thereof, with no intermediate plug elements or blockage. Any other convenient length, sufficient to enable a user to conveniently grasp and support said third tubular element 17 in a raised vertical orientation such that said upper end 27 is at least ten feet (at least in excess of 3.0 meters) above the local earth surface, may be employed. However, a length in excess of six feet (in excess of 183.0 centimeters) is to be avoided as creating difficulty in use, as will become evident from a description of use of the apparatus 11 given later herein. The third tubular element 17 may also, in an alternate embodiment be formed of a solid cylindrical stock in lieu of the preferred annular cylindrical stock.
Referring next to FIG. 3, showing an end view of the assembly of the apparatus 11 taken from the top of said apparatus 11, together with FIG. 2, the apparatus 11 may be observed to be an assembly of said first tubular element 14, said second tubular element 16, and said third tubular element 17. This assembly is accomplished by arranging the longitudinal axes of the three tubular elements 14, 16, and 17 to respectively orthogonally intersect an imaginary plane so as to be at the vertices of an equilateral triangle, with respective outer wall surfaces of the tubular elements in appropriate mutual contact. In such an arrangement, the exposed planar surface of the cap element 18 rigidly coupled to the upper end 19 of the first tubular element 14, the upper end 24 of the second tubular element 16, and the upper end 27 of the third tubular element 17 are to be disposed to be substantially coplanar. Rigidity of the assembly of the apparatus 11 is provided by rigidly coupling abutting longitudinal extents of the three tubular elements 14, 16, and 17 to each other, such as by longitudinally extending weld beads 29.
Referring again to FIG. 2, the extension element 12 is formed of a segment 30 of right circular cylindrical solid stock, having an upper end 31 thereof and a lower end 32 thereof. The segment 30 is, in the preferred embodiment, configured to have a diameter substantially equivalent to the diameter of the electrical ground rod 10 of FIG. 1, so that said segment 30 may be freely inserted axially into said cavities of the tubular elements of the apparatus 11, as will be described in subsequent discussions of the use of the present invention. A short tubular segment 33, formed from the same tubular stock as the three tubular elements 14, 16, and 17, is rigidly affixed to said lower end 32 of the segment 30 so as to be substantially coaxially aligned therewith. A lower end 34 of the short tubular segment 33 remains open to form an internal cylindrical cavity.
While precise lengths of the segment 30 and the tubular segment 33 forming the extension element 12 are left to user driven selection, as a practical matter, the length of the tubular segment 33 should be sufficient to enable engaging the extension element 12 onto the upper end of the electrical ground rod 10 while maintaining approximate coaxial alignment therebetween. Typically, a length of between three inches (approximately 7.6 centimeters) and six inches (approximately 15 centimeters) is preferred. As for the solid segment 30, its length is preferred to be approximately twenty-five inches (approximately 63.5 centimeters) so that the upper end 31 of the segment 30 will contact the high tensile strength plug intermediate within said second tubular element 16, when said segment 30 is axially inserted into either open cavity of said second tubular element 16, without permitting the corresponding end of said second tubular element 16 to come into contact with said tubular segment 33 of said extension element 11.
Referring next to FIG. 4, a first stage of use of the present invention is illustrated. Initially, as shown in FIG. 4a, the apparatus 11 is mated to an upper end of an electrical ground rod 10 such that an upper portion of said electrical ground rod 10 is axially inserted into the cylindrical cavity of the first tubular element 14. The combination of the apparatus 11 and the electrical ground rod 10 is then oriented so that the lower end of the electrical ground rod 10 is in contact with the surface of the earth at a desired point of entry 36, with the electrical ground rod 10 being held in a substantially vertical attitude. In this orientation, a user, standing proximately adjacent the desired point of entry 36, grasping the third tubular element 17 as a handle and raising, in a direction indicated by an arrow 37, the apparatus 11 vertically through a distance less than that enabling the apparatus 11 to become disengaged from the upper end of the electrical ground rod 10 and then forcefully drawing the apparatus vertically downwardly, in a direction indicated by an arrow 38, so that the cap element 18 rigidly affixed to the upper end 19 of the first tubular element 14 impacts on the upper end of the electrical ground rod 10, a downwardly directed force is imparted onto the upper end of the electrical ground rod 10, causing the lower end of the electrical ground rod 10 to be partially driven into the earth. Repeatedly raising and forcefully lowering the apparatus 11 onto the upper end of the electrical ground rod 10, respectively in the directions indicated by the arrows 37 and 38, will cause the electrical ground rod 10 to be driven substantially vertically into the earth through a portion of its longitudinal extent to a position approaching that shown by FIG. 4b. It is to be noted that the user should frequently reposition the point of grasping along the extent of the third tubular element 17 to avoid disengaging the first tubular element 14 from the upper end of the electrical ground rod 10.
When the lower end 28 of the third tubular element 17 approaches the local earth surface, the first stage of use of the present invention is concluded. The apparatus 11 is then disengaged from the electrical ground rod 10 by grasping the third tubular element 17 such that the apparatus 11 may be vertically raised, in a direction indicated by an arrow 39, until the lower end 20 of the first tubular element 17 is substantially higher than the upper end of the electrical ground rod 10, as shown in FIG. 4c.
Referring next to FIG. 5, illustrating a second stage of use of the present invention, the vertical raising of the apparatus 11 suggested by FIG. 4c is continued, as shown in FIG. 5a, through a distance sufficient such that the lower end 26 of the second tubular element 16 is at an elevation greater than the upper end of the electrical ground rod 10. The apparatus 11 is then rotated, as indicated by an arrow 40, about a centroid of the imaginary equilateral triangle of the three tubular elements 14, 16, and 17, shown in FIG. 3, and in the plane thereof, until the cavity within said second tubular element 16, extending upwardly from its lower end 26, is aligned with the upper end of the electrical ground rod 10. The apparatus 11 is then lowered, in a direction indicated by an arrow 41, so that an upper portion of the extent of the electrical ground rod 10 is axially inserted into the lower cavity of the second tubular element 16 and the intermediate plug 23 rests upon the upper end of the electrical ground rod 10, as shown in FIG. 5b.
Appropriately regrasping the third tubular element 17 as a handle, the user then raises the apparatus 11, in the direction indicated by the arrow 37, through a distance less than that enabling disengagement of the lower segment 22 of the second tubular element 16 from the upper end of the electrical ground rod 10, and then forcefully downwardly draws the apparatus 11, in the direction indicated by the arrow 38, so as to cause the plug 23 to impact upon the upper end of the electrical ground rod 10, causing the electrical ground rod 10 to be further driven substantially vertically into the earth. Raising and forcefully lowering the apparatus, respectively in the directions indicated by the arrows 37 and 38, regrasping the third tubular element 16 as necessary, enables the user to drive the electrical ground rod 10 into the earth to an extent suggested by FIG. 5c.
When the lower end 28 of the third tubular element 17 approaches interferring proximity to the local earth surface, in its lowered position, the second stage of use of the present invention is concluded. The apparatus 11 is then disengaged from the upper end of the electrical ground rod 10, as shown in FIG. 5d, by vertically raising it, in a direction indicated by an arrow 42 through a distance sufficient to bring the lower end 26 of the second tubular element 16 to an elevation greater than the then driven elevation of the upper end of the electrical ground rod 10.
Referring next to FIG. 6, illustrating a third stage of use of the present invention, the apparatus 11, elevated as suggested in FIG. 5d, is first rotated end for end in a vertical plane about an axis perpendicular to the longitudinal extent of the apparatus 11, as indicated by an arrow 43 in FIG. 5d and in FIG. 6a, such that the erstwhile upper segment 21 of the second tubular element 16 assumes an orientation wherein its internal cavity, extending from the original upper end 24 to the plug 23 is vertically aligned over the upper end of the electrical ground rod 10, the open end 24 being at a present lowermost position as shown in FIG. 6a. The apparatus 11 is then vertically lowered, in a direction indicated by an arrow 44, until the upper end of the electrical ground rod 10 is axially inserted into the cavity of the second tubular element 16 at the end 24, with the plug 23 resting upon the uppermost end of the electrical ground rod 10, as shown in FIG. 6b. Again, the user, regrasping the third tubular element 17 as a handle as may be necessary, continues driving the electrical ground rod 10 vertically into the earth by raising and forcefully lowering the apparatus 11 so as to cause the plug 23 to impact upon the upper end of the electrical ground rod 10. These repeated actions, respectively in the directions indicated by the arrows 37 and 38, cause driving of the electrical ground rod 10 from the position suggested by FIG. 6b to the position suggested by FIG. 6c, which also represents an approximate end position for the third stage of use of the present invention. Upon reaching the position suggested by FIG. 6c, whereat the initially upper ends 18, 24, and 27 of the first tubular element 14, the second tubular element 16, and the third tubular element 17, respectively, now oriented to be the lower end of the apparatus 11, approach contact with the local earth surface, the apparatus 11 is disengaged from the electrical ground rod 10 by raising the apparatus 11, in a direction indicated by an arrow 46, until the end 24 of the second tubular element 16 is at an elevation greater than the upper end of the electrical ground rod 10. The apparatus 11 is then temporarily set aside in preparation for the final stage of use of the present invention.
Referring lastly to FIG. 7, illustrating the final stage of use of the present invention, the extension element 12 is positioned over the upper end of the electrical ground rod 10 such that the open end 34 of the tubular segment 33 is vertically aligned with the upper end of the electrical ground rod 10, the solid segment 30 of the extension element 12 extending substantially vertically upwardly therefrom, as shown in FIG. 7a. The apparatus 11 is repositioned, as in FIG. 6d, so that the end 24 of the second tubular element 16 is vertically over the upper end 31 of the solid segment 30 of the extension element 12, also as shown by FIG. 7a. The tubular segment 33 of the extension element 12 is then engaged upon the upper end of the electrical ground rod 10, the end 24 of the second tubular element 16 of the apparatus 11 is engaged upon the upper end 31 of the solid segment 30 of the extension element 12, and the elements are lowered, in a direction indicated by an arrow 47, to assume the relative positions shown in FIG. 7b, wherein the lower end 32 of the solid segment 30 of the extension element 12 rests upon, and in contact with, the upper end of the electrical ground rod 10 enclosed within the cavity, and the plug 23 within the second tubular element 16 of the apparatus 11 rests upon, and in contact with, the upper end 31 of the solid segment 30 of the extension element 12. It is to be again noted that the end 24 of the second tubular element 16 is not in contact with the tubular segment 33 of the extension element 12.
As in the previous stages of use of the present invention, the user grasps the third tubular element 17 as a handle and performs repeated raising and forceful lowering, in the respective directions indicated by the arrows 37 and 38, of the apparatus 11 relative to the extension element 12 so as to cause the plug 23 to impact upon the upper end 31 of the solid segment 30 of the extension element 12, which communicates a downward driving force onto the upper end of the electrical ground rod 10 from the lower end 32 of the solid segment 30. This procedure is continued until the interface between the lower end 32 of the solid segment 30 of the extension element 12 and the tubular segment 33 of the extension element 12 is substantially coplanar with the local earth surface. It is to be noted that the tubular segment 33 of the extension element 12 becomes driven into the earth surface during this stage of use, as is shown by FIG. 7c. Upon reaching this position, the electrical ground rod 10 has become fully driven vertically into the earth along its entire extent. The apparatus 11 and the extension element 12 are then disengaged from each other and from the upper end of the electrical ground rod 10, leaving a fully emplaced electrical ground rod, as shown in FIG. 7d.
While the foregoing has described, in detail, a preferred embodiment of the present invention and the manner of its use, these descriptions have also suggested a plurality of alternate embodiments having differing physical dimensions from those set forth in the above. It is emphasized that, except for such constraints as may be set forth herein, all such variations in dimensions are contemplated to be within the scope of the present invention. It is further contemplated that placement of the impacting surfaces may be further varied, and that the assembly of the three tubular elements 14, 16, and 17 to form the apparatus 11 may assume a configuration other than that of the equilateral triangle of the preferred embodiment. These, and all other alternate embodiments and modifications that may become obvious or reasonable from the foregoing descriptions, are within the contemplation of the herein invention, which is to be limited in scope solely by the claims appended hereto.
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Three tubular elements are rigidly bundled together so as to have, in use, a common upper end elevation. The first element is closed at its upper end by a rigid cap element and depnds from the common upper end by approximately 30 centimeters (approximately two feet). The second element consists of a substantially identical length of tube, open at its upper end, depending to a plug element closing its lower end, from which another identical length of tube coaxially depends to an open lower end at about 62 centimeters (marginally greater than four feet) below the upper end. The third element depends from the common upper end through a distance preferred to be between one hundred fifty two centimeters and one hundred eighty three centimeters (between approximately five and six feet), for use as a handle. Included is an extension element, formed of a length of solid rod, of the same diameter as a ground rod an marginally longer than the upper tubular segment of the second element, to which a short segment of the same tubular stock is coaxially rigidly affixed. Alternate embodiments and uses are described.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of, and claims priority from, co-pending patent application Ser. No. 11/036,907, filed Jan. 14, 2005, and entitled Removable And Relayable Floor Covering.
FIELD OF THE INVENTION
[0002] The present invention generally relates to floor coverings and their installation and, more particularly to a removable and repositionable tile floor coverings.
BACKGROUND OF THE INVENTION
[0003] There is always a need for efficiency, economy and speed in the construction industry. The surface-covering portion of the construction industry has also had the challenge of escalating costs incurred by the labor, material, and time associated with flooring installation and removal procedures. This waste of time, labor, and materials is particularly evident in the flooring industry where the need for durability and replaceability are constant conflicting requirements. Conventional flooring is traditionally installed on sub-floors by either pre-glue or glue applications, interlocking mechanisms, or underlayment systems. For any floor to be durable and slip-resistant, it needs to be securely installed on the sub-floor. However, the more solidly it is secured to the sub-floor, the more difficult and costly it will be to install or remove the flooring.
[0004] Prior to a conventional flooring installation, much labor, time and material is wasted in the removal of existing flooring and the return of the damaged sub-floor to ideal conditions for the installation of the new floor. The removal of existing flooring often causes glue residue to remain on the top surface of the sub-floor. The process of removal of existing flooring or the residual, hardened glue also often damages the sub-floor. When the removal is complete, additional labor, time and material are required to install the new floor securely to the sub-floor. Unnecessary environmental cost is also incurred in the wasteful discarding of the old flooring material, and in the repeated use of another new set of the cement, adhesive or underlayment system required for the new flooring.
[0005] Self-adhesive tiles, produced with or without release paper, are known in the art and may help to eliminate the re-application of glue when installing new flooring materials. Interlocking flooring systems have also been developed to eliminate the application of glue altogether by making the adjacent tiles interlock. Underlayment systems have been developed in the art to eliminate faulty sub-floor conditions and enable new flooring to be fastened onto the underlayment systems directly instead of on to a sub-floor.
[0006] For example, in U.S. Pat. No. 6,129,967 a system for securing brittle ceramic tiles to a sub-floor without a supporting adhesive substrate is disclosed. A liner is used to provide structural support and an energy absorbent layer is present which allows the tile to withstand greater forces of abrasion without breaking. The liner is adhered to a sub-floor and the tiles are placed inside and are anchored to the liner and an impact resistant ceramic layer.
[0007] U.S. Pat. No. 6,694,689 discloses a modular flooring system which utilizes a free-lay support base plate into which replaceable wear surface tiles fit. The base plate provides for a level floor surface when placed over a preexisting worn floor and for the removal and replacement of flooring within the base plate superstructure. The composite base plate structure permits independent temporary displacement of each of the tiles.
[0008] U.S. Pat. No. 4,654,244 discloses a loose-lay floor structure including two layers of reinforced material that are suitable for use over stable and unstable sub-floors. Rigidity in the flooring is achieved by two layers of reinforced material sandwiching a cushion layer. Surface layers are placed on the outside of the reinforced layers. This reinforcement is designed to prevent buckling, curling and doming under a rolled load.
[0009] U.S. Pat. No. 6,751,917 discloses a floor tile structure without an adhesive coating at the bottom. Each tile surface layer and bottom layer are attached respectively, on the upper and the lower surfaces of soft double sided adhesive tape with pressure sensitivity. The surface layer is possibly made of rock, metal, or other hard material and the periphery is a smooth cross-section. Tiles are joined by placing the adhesive on the middle protruding convex layer of one tile onto the convex edge of the adjoining one and bonding the two together in the middle, leaving no need for bottom adhesion.
[0010] U.S. Pat. No. 6,751,912 discloses a modular interlocking tile and flooring system. Each tile is adapted to be coupled to another interlocking tile. Each tile includes a body having a playing surface and two male and two female interlocking sides. The interlocking mechanism is adapted to allow the modular interlocking tiles to connect together in a staggered fashion.
[0011] U.S. Pat. No. 6,802,159 discloses a roll-up tile system. Individual tiles lock together in a manner to form a plurality of non-bendable tile joints. The tile includes a hinge or fold line along an axis. The hinges allow the multi-tile surface to be rolled up into a hollow tube from any direction along one of the axes. The rolled up floor panel consists of a plurality of tile panels.
[0012] U.S. Pat. No. 6,769,217 discloses an interconnecting disengageable flooring system. The system includes two or more flooring panels including a top wear surface and a bottom surface for contact with the support structure. The panels have at least three edges and all edges have recesses formed therein. The system also comprises a connector having a base and a projection extending vertically from the base. The projection extending from the base is shaped to be received in a disengageable vertical connected fashion into the recesses of the panels.
[0013] U.S. Pat. No. 6,803,099 discloses a self-adhering surface covering having a wear surface and a pressure-sensitive adhesive layer on the lower surface of the wear surface and a barrier layer disposed on the adhesive layer. The surface covering has substantially no tack at about 10 psi at 140° F. but has tack at about 20 psi at 75° F. An adhesive which is substantially non-stringing may also be employed in the adhesive layer. The barrier layer includes substantially non-adhesive particles which have a crash resistance of at least about 10 psi while disposed on the adhesive layer. The method of making the self-adhering surface covering includes applying an adhesive to a substrate to form an adhesive layer having an adhesive surface, and applying a barrier layer comprising substantially non-adhesive particles to the adhesive surface to form the surface covering. The particles have a crush resistance of at least about 10 psi while disposed on the adhesive layer.
[0014] U.S. Pat. No. 6,905,100 discloses an adhesive sheet strip, single-sidedly or double-sidedly pressure-sensitively adhering, redetachable by extensive stretching/pulling on a grip tab in the direction of the bond plane, where the grip tab is such that it has a static frictional force of at least 170 cN.
[0015] U.S. Published Patent Application No. 20040129365 discloses a pre-glued underlayment assembly for a floor covering system having a substantially rigid underlayment. The underlayment has an upper and a lower surface and a pressure sensitive adhesive layer disposed on the upper surface and a release layer on the adhesive layer.
[0016] None of the foregoing prior art flooring systems and methods are completely satisfactory. There remains a need for a flooring systems that is durable and slip-resistant against foot traffic when adhered to a sub-floor, but that can be installed and removed readily without additional investment in time, labor, cost, tools or energy. In addition, there is a need in the art for a flooring system with a nearly 100% clean removeability (i.e., that will not damage a sub-floor, leave appreciable glue residue, nor become delaminated or damaged in its removal) and that retains all of its beneficial features and original adhesion tack in place so that it can be repositioned or reused after repeated installations and removals. It is likewise advantageous and desirable to provide a method of flooring installation and replacement that is efficient and clean without the burden of glue residue removal and the creation of material waste in course. Also, it is desirous to provide a moisture release enhancement as an additional feature in the flooring to minimize the dirt and grime collection in and under the tile seams and to release the pressure built-up due to moisture in the sub-floor. Additionally, it is desirous to provide a method of floor adhesion that is not “tacky” or “sticky” to the touch, does not leave a glue residue, is slip resistant and suitable for both permanent and temporary tile installations. Furthermore, it is desirous to provide a solution in flooring that can be installed, removed, and re-installed with a Do-It-Yourself “Stick, Peel, Stick” ease so the flooring can be transferred intact from one place to another by an untrained person, much like a piece of furniture.
SUMMARY OF THE INVENTION
[0017] The present invention relates to removable flooring and surface coverings that are a structural improvement of floor tiles, sheets, or planks, including floor tiles, sheets, and planks or sections of varying sizes and shapes and surface types including those made from polyvinyl chloride, rubber, linoleum, polymeric resins, reinforced resins, vinyl composite, or other resilient materials, carpet, stones, ceramic, metals, glass, textiles, wood, composites thereof in desired combinations, veneers thereof in desired combinations, and laminates thereof in desired combinations, all of which are hereinafter referred to as a “floor section, floor covering, or floor tile”.
[0018] More particularly, the present invention provides a floor covering having a dual backing layer comprising a foam layer coated with a repositionable, pressure sensitive adhesive layer. This dual backing layer allows the floor covering to be installed directly to a sub-floor surface with only a slight application of pressure, and without any additional application of glue or underlayment systems. Significantly, this dual backing layer-enhanced floor covering can be removed readily from the sub-floor without any glue residue or any damage done to the sub-floor or to the flooring substrate. Additionally, that very same floor covering may be reinstalled again without losing the effectiveness of its original tack. Thus, a loose-lay floor covering is provided that is self-adhering, removable and relayable, otherwise referred to as, “stick, peel, stick.”
[0019] In one embodiment, a floor covering is provided including a top surface or wear layer often having a backing layer arranged below the wear layer. A cushion layer is arranged below the backing layer which includes a bottom-most embossed surface that defines a plurality of channels that are separated one from another by a plurality of lands. A repositionable, pressure sensitive adhesive that has an initial tack is applied onto the bottom-most surface of the cushion layer so that the cushion layer (i) adheres to a surface thereby to hold the cushion layer in place after application of a pressure, but (ii) allows removal of the cushion layer from the surface absent a substantial diminution of the initial tack so that the floor covering may be repositioned on the sub-floor.
[0020] In another embodiment, floor covering is provided that includes a top surface or wear layer. A divided cushion layer is located below the backing layer which has a bottom-most embossed surface that defines a plurality of intersecting channels that are separated one from another by a plurality of lands wherein each of the lands comprises a top surface. A repositionable, pressure sensitive adhesive that has an initial tack is applied to the top surface of the lands so that the divided cushion layer (i) adheres to a surface thereby to hold the cushion layer in place after application of a pressure, and (ii) allows removal of the cushion layer from the surface absent a substantial diminution of the initial tack so that the floor covering may be repositioned on the sub-floor.
[0021] A method for adjusting the surface contour of a floor covering is also provided in which a divided cushion layer is formed on a bottom surface of a self-adhesive, loose-lay tile so as to define a plurality of removable pad segments. In order to compensate for a prominence or depression on a sub-floor, e.g., a nail or portion of a floor board or a hole or low spot, at least one of the pad segment is removed from its position of the bottom-most surface of the floor covering thereby forming a void in the divided cushion layer that is suitable for accepting and receiving the prominence.
[0022] In another method for adjusting the surface contour of a floor covering, a divided cushion layer is formed on a bottom surface of a self-adhesive, loose-lay tile so as to define a plurality of removable pad segments. In order to compensate for a prominence or depression on a sub-floor, e.g., a nail or portion of a floor board or a hole or low spot, at least one of the pad segment is removed from its position of the bottom-most surface of the floor covering thereby forming a void in the divided cushion layer that is suitable for accepting and receiving the prominence, and the removed pad segment is positioned atop a portion of the divided cushion layer that corresponds to the position of the depression in the sub-floor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] These and other features and advantages of the present invention will be more fully disclosed in, or rendered obvious by, the following detailed description of the preferred embodiments of the invention, which are to be considered together with the accompanying drawings wherein like numbers refer to like parts and further wherein:
[0024] FIG. 1 is a perspective view of a floor covering without moisture-release channels according to the present invention;
[0025] FIG. 2 is a cross-sectional view of a floor covering without moisture-release channels according to the present invention;
[0026] FIG. 3 is a perspective view of a floor covering with moisture-release channels according to the present invention;
[0027] FIG. 4 is a cross-sectional view of a floor covering with moisture-release channels according to the present invention;
[0028] FIG. 5 is a flowchart of one typical production process according to the invention;
[0029] FIG. 6 is a perspective view of an alternative embodiment of floor covering formed in accordance with the present invention.
[0030] FIG. 7 is a bottom perspective view of the floor covering shown in FIG. 6 ;
[0031] FIG. 8 is a broken-away and enlarged view of a corner portion of the floor covering shown in FIG. 7 ;
[0032] FIG. 9 is a cross-sectional view of a portion of the floor covering shown in FIG. 7 ; a floor covering formed in accordance with the alternative embodiment of the present invention;
[0033] FIG. 10 is a broken-away and enlarged view of the floor covering shown in FIGS. 7, 8 , and 9 , showing an individual pad segment, lands, and channels in accordance with the present invention;
[0034] FIG. 11 is a broken-away perspective view showing the top surfaces of pad segments on the bottom-most surface of a floor covering formed in accordance with the present invention;
[0035] FIGS. 12 and 13 are a broken-away perspective views similar to that of FIG. 11 , showing a pad segment being removed from the floor covering;
[0036] FIG. 14 is a perspective view of a portion of a workman's hand holding a pad segment formed in accordance with the present invention;
[0037] FIG. 15 is a broken-away illustration of a floor covering formed in accordance with the present invention being applied to a sub-floor;
[0038] FIG. 16 is a perspective view of a broken-away corner portion of a floor covering showing a first pad segment being applied over top of a second pad segment so as to increase the thickness of the floor covering in that region;
[0039] FIG. 17 is a perspective view of a bottom of a floor covering formed in accordance with the present invention showing an edge strip with pad segments removed to accommodate a prominence on a sub-floor;
[0040] FIG. 18 is a perspective view of a bottom of a floor covering formed in accordance with the present invention showing a central void formed by the selective removal of pad segments so as to accommodate a prominence on a sub-floor and portion of the floor covering bottom having additional pad segments added so as to compensate for unevenness or depressions in the sub-floor;
[0041] FIG. 19 is a perspective view of a bottom of a floor covering formed in accordance with the present invention showing a corner pad segment removed to accommodate a prominence on a sub-floor and a corner having a doubled pad segment to compensate for a corresponding depression in the sub-floor;
[0042] FIG. 20 is a broken-away, perspective view of a corner portion of a floor covering formed in accordance with the present invention showing a double-thickness of pad segments on the bottom portion of a floor section acting to compensate for a depression in the sub-floor;
[0043] FIGS. 21 and 22 are cross-sectional views of a pair of side-by-side floor tiles formed in accordance with the present invention where a portion of one of the floor tiles sits atop a recess in a sub-floor; and
[0044] FIGS. 23 and 24 are cross-sectional views of floor tiles formed in accordance with the present invention where a portion of the floor tile sits atop a prominence in a sub-floor.
DETAILED DESCRIPTION OF THE INVENTION
[0045] This description of preferred embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description of this invention. The drawing figures are not necessarily to scale and certain features of the invention may be shown exaggerated in scale or in somewhat schematic form in the interest of clarity and conciseness. In the description, relative terms such as “horizontal,” “vertical,” “up,” “down,” “top” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and normally are not intended to require a particular orientation. Terms including “inwardly” versus “outwardly,” “longitudinal” versus “lateral” and the like are to be interpreted relative to one another or relative to an axis of elongation, or an axis or center of rotation, as appropriate. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise.
[0046] The term “operatively connected” is such an attachment, coupling or connection that allows the pertinent structures to operate as intended by virtue of that relationship. In the claims, means-plus-function clauses, if used, are intended to cover the structures described, suggested, or rendered obvious by the written description or drawings for performing the recited function, including not only structural equivalents but also equivalent structures.
[0047] Referring to FIGS. 1-5 , a floor section 10 that is formed in accordance with a first embodiment of the present invention may be formed, at least in part from any one of the following floor covering material types including, but not limited to polyvinyl chloride, rubber, linoleum, polymeric resins, reinforced resins, vinyl composite, or other resilient materials, carpet, stones, ceramic, metals, glass, textiles, wood, composites thereof in desired combinations, veneers thereof in desired combinations, and laminates thereof in desired combinations, all of which are referred to hereinafter as a “floor section”.
[0048] Floor section 10 often comprises a self-adhesive, loose-lay installed floor covering which may have multiple layers or be homogenous, i.e., natural stone or wood, including an upper wear surface 11 and an internal adhesive layer 12 that secures upper wear surface 11 to a cushion material layer 13 . Another adhesive layer 14 is provided by a backing coating of cured or non-cured adhesive. More particularly, upper wear surface 11 is preferably formed from polyvinyl chloride (PVC), ceramic, stone, or other suitable surface materials, and can be of varying width, thickness, density and edge shape design, color, pattern, chemistry, or composition dependent on the specific material of which it is made. Upper wear surface 11 is defined by its upper surface 11 a , which forms the uppermost wear surface of floor section 10 , and its lower surface 11 b , the bottommost surface of floor section 10 .
[0049] Cushion material layer 13 is defined by its upper surface 13 a and lower surface 13 b . Cushion material layer 13 often comprises a variety of soft, resilient materials including, but not limited to foamable polymers, and in particular, foam layers such as chemical blown polyvinyl chloride plastisols/organosols, acrylics, rubber foams, polyurethane foams, froth foams such as polyvinyl chloride plastisol, acrylics, melt processed foams such as polyvinyl chloride, polyethylene, ethylene vinyl acetate, metallocene polyolefins, elastomeric polyolefin copolymers. Additionally, any soft, resilient or cushioned material which is foamed or non-foamed may also be employed. The thickness of cushion material layer 13 is often about 0.1 mm to 1.0 mm, with about 0.2 mm often preferred. Cushioned material layer 13 provides for an evenly distributed contact between floor section 10 and a sub-floor. This, in-turn, significantly increases the degree of leveling adhesion of floor section 10 , and enhances the acoustic absorption of floor section 10 while making the finished floor more comfortable to walk on and more shock-absorbent.
[0050] Upper wear surface 11 is adhered to cushion material layer 13 by an internal adhesive layer 12 . Internal adhesive layer 12 adheres lower surface 11 b to an uppermost surface 13 a of cushion material layer 13 . A repositionable, pressure sensitive adhesive layer 14 is often formed or applied as a coating of cured or non-cured adhesive that adheres onto the sub-floor with very slight pressure, but allows lifting, removal, and repositioning of floor section 10 with its original “tack” substantially unaffected, and without glue residue or delaminating the sub-floor. The repositionable, pressure sensitive adhesive that comprises internal adhesive layer 14 may include many of the adhesives that are non-curable or curable, including rubber-type adhesives, PVC-type adhesives, acrylic adhesives, e-beam curable acrylic adhesives, vinyl acetate-type adhesives, urethane-type adhesives and combinations thereof. Lower surface 14 b of repositionable, pressure sensitive adhesive layer 14 must provide sufficient adhesive properties to maintain floor section 10 in place during use, but also be releasable so that floor section 10 can be removed and repositioned, sometimes repeatedly. In other words, repositionable, pressure sensitive adhesive layer 14 advantageously adheres to a surface with an initial tack that holds the cushion layer in place after application of a pressure, but allows for the removal of the cushion layer from the surface (e.g., sub-floor) absent a substantial diminution of its initial tack. One adhesive that has been found to provide adequate results is made of modified acrylate, with a viscosity of 3000-5000 cps/25° C., a density of 1.0-1.1 g/cm 3 , and a curing speed greater than 10 M/min/Lamp (80 Wcm −1 ) with 80% active component. The coating method for this particular adhesive can be either a reverse roll coater, a forward roll coater, a doctor blade, an air knife, or other similar coating apparatus. Of course, repositionable, pressure sensitive adhesives that do not need to be cured, as are well known in the art, may also be used in connection with the present invention.
[0051] Lower surface 13 b adheres to a backing coating of cured adhesive layer 14 . In one embodiment, the criteria for the repositionable, pressure sensitive adhesive layer applied on foam layer lower surface 13 b , would be any curable adhesive which: (1) has undergone curing or cross-linked processing; (2) has initial tack that's sufficient to bond or hold the particles to the adhesive surface and maintain the back layer in contact with the sub-floor, (3) be non-stringing and relatively resistant to penetration or compression of particles, (4) about 0.03 mm to 0.05 mm thick average, but can be less than 0.03 mm or greater than 0.05 mm depending on the adhesive used. Cushioned material layer 13 may have about 0.5 mm to 3.0 mm thickness, but could vary depending on the foam material used. The repositionable, pressure sensitive adhesive thickness can be conventionally determined, typically between 0.01 mm to 0.3 mm, but preferably lower than a thickness of 0.1 mm.
[0052] Referring to FIGS. 3 and 4 , another embodiment of the invention comprises a floor section 20 that includes a moisture-releasing channel layer 24 . More particularly, floor section 20 comprises multiple layers, including a wear surface layer 21 that forms the uppermost layer that is seen and is the contact and wear surface. Wear surface layer 21 is defined by its upper surface 21 a which is the uppermost contact and wear surface of sample floor section member 20 and its bottom surface 21 b . An internal adhesive layer 22 is adhered to a lower surface 21 b of wear surface layer 21 . Wear surface layer 21 is preferably formed from polyvinyl chloride (PVC), ceramic, stone, or other suitable surface materials, and can be of varying width, thickness, density and edge shape design, color, pattern, chemistry, or composition dependent on the specific material of which it is made. Wear surface layer 21 is often applied to cushion material layer 23 with an internal adhesive layer 22 . Internal adhesive layer 22 adheres to bottom surface 21 b and surface 23 a which is the uppermost surface of cushion material layer 23 .
[0053] When cushion material layer 23 is positioned below wear surface layer 21 , the lowermost portion of it defines moisture-releasing channel layer 24 . Moisture-releasing channel layer 24 comprises a plurality of lands 26 that are located between and separate a plurality of troughs or channels 27 that are arranged in regular intervals across the bottom of floor section 20 . Moisture-releasing channel layer 24 is preferably formed by pressing or embossing the bottom-most surface of cushion material layer 23 so as to compress portions of cushion material layer 23 to form troughs or channels 27 while maintaining the portions of cushion material layer 23 adjacent to troughs or channels 27 at or near to their original thickness so as to define lands 26 . Additionally, depending upon embossing conditions, lands 26 can also be compressed to less than their original thickness. Repositionable, pressure sensitive adhesive layer 14 b is applied to lower surface 23 b of cushion material layer 23 . In one embodiment, ( FIG. 3 ) lands 26 and channels 27 may extend parallel to each other for the length and width of floor section 20 . Repositionable, pressure sensitive adhesive layer 14 b advantageously adheres to a surface with an initial tack that holds the cushion layer in place after application of a pressure, but allows for the removal of the cushion layer (i.e., the tile) from the surface (e.g., sub-floor) absent a substantial diminution of the initial tack.
[0054] Cushion material layer 23 may comprise any one or combination of soft, resilient materials including, but not limited to foamable polymers or foam such as chemical blown polyvinyl chloride plastisols/organosols, acrylics, rubber foams, polyurethane foams, froth foams such as polyvinyl chloride plastisol, acrylics, melt processed foams such as polyvinyl chloride, polyethylene, ethylene vinyl acetate, metallocene polyolefins, elastomeric polyolefin copolymers, so long as they are susceptible to taking a set after being compressed or other wise embossed in accordance with that aspect of the invention. Additionally, any soft, resilient or cushioned material which is foamed or non-foamed may also be employed. The thickness of cushion material layer 23 and lands 26 is often about 0.1 mm to 1.0 mm, with about 0.2 mm being often preferred, with those portions of cushion material layer 23 that define troughs or channels 27 having an embossed thickness of about 0.2 mm or less.
[0055] Repositionable, pressure sensitive adhesive layer 14 b is applied over the bottom-most surface of moisture-releasing channel layer 24 , and functions as a releasable glue to hold floor section 20 in place on a sub-floor, while advantageously allowing floor section 20 to be removed, repositioned, and then relayed onto the sub-floor. Repositionable, pressure sensitive adhesive layer 14 b may be formed of rubber-type adhesives, acrylic adhesives, including e-beam curable acrylic adhesives, vinyl acetate-type adhesives, urethane-type adhesives, and combinations thereof, or any other pressure sensitive adhesives that are curable or non-curable as are well known in the art.
[0056] Moisture-releasing channel layer 24 molds to the sub-floor upon which it is laid and reinforces the surface tension of the floor section's adhesion on the sub-floor. Such molding resists horizontal or diagonal pull forces and movement on the sub-floor. Floor section 20 is best removed from a sub-floor with a pull parallel to the vertical structural lining on the cushion material layer 23 as a result of the provision of channels 27 . Floor section 20 remains intact and cannot be easily displaced with a horizontal or diagonal pull. Moisture releasing channel layer 24 allows water to evaporate from its point of contact with the sub-floor, helping to maintain the floor section's adhesion to the sub-floor and to maintain the aesthetic value of floor section 20 . This arrangement also prevents unwanted particles from collecting and soiling floor section 20 or distressing the point of contact of moisture-releasing channel layer 24 with the sub-floor.
[0057] Referring to FIG. 5 , a flowchart is provided of a typical production process for a floor section 20 in the form of a vinyl tile formed in accordance with the present invention. The production process follows generally conventional means of tile manufacturing either via extrusion, calendar or heat pressure lamination. With reference to schematic 41 , the process may begin with a top layer that may be a polyvinyl film that may also include a printed design. The polyvinyl chloride film is then extruded into a tile by heat lamination according to the process shown in schematic 42 . The process referenced in schematic 42 begins with a polyvinyl chloride compound mixed with calcium carbonate and processed, via a Bumberly, and extruded into tile by a crushing machine. The tile surface may then be embossed, cooled, and annealed. Glue is then applied to the tile back. The foam layer, the first layer of the current invention is then combined to the tile material in accordance with the invention. Schematic 43 shows the process for incorporation of the foam layer. Schematic 43 begins with a foamable material compound processed, via a Bumberly, extruded, and cut to fit the tile material already produced.
[0058] As referenced in schematic 41 , after the foam is adhered onto the tile's backing and formed, the back surface of the tile is smoothed, embossed to yield lands 26 and channels 27 , and then the adhesive is applied onto the foam layer and followed, in some embodiments, by drying/curing with ultraviolet light. The production process is then complete, and the tile is ready for packing.
[0059] Referring to FIGS. 6-24 , a further embodiment of the present invention provides for removal and readjustment of a cushion layer to accommodate unevenness in the sub-floor. More particularly, a floor section 50 comprises multiple layers including wear surface layers 52 , a backing layer 54 and a dividable cushion material layer 56 . Wear surface layers 52 include an upper-most clear film surface 58 and often a print film layer 60 that form the uppermost layers that are seen and that form the contact and wear portion of floor section 50 . Backing layer 54 may be formed from polyvinyl chloride (PVC), ceramic, stone, or other suitable support materials, and can be of varying width, thickness, density and edge shape design. An internal adhesive layer 62 is adhered to a lower layer surface of wear surface layers 52 so as to adhere an uppermost surface of backing layer 54 and another internal adhesive layer 63 (a repositionable, pressure sensitive adhesive layer, such as adhesive layer 14 b ) is adhered to a bottom surface of backing layer 54 so as to adhere an uppermost surface of dividable cushion material layer 56 . Internal adhesive layer 63 advantageously adheres to the bottom surface of backing layer 54 with an initial tack that holds dividable cushion material layer 56 in place after application of a pressure, but allows for the removal of dividable cushion material layer 56 from the bottom surface of backing layer 54 absent a substantial diminution of an initial tack.
[0060] Dividable cushion material layer 56 comprises a plurality of removable pad segments 70 , i.e., cushion material layer 56 is arranged and constructed so as to be separated or split into a plurality of separate and discrete segments. Each pad segment 70 is separated from its adjacent pad segments by score lines 72 that allow for removal of individual pad segments 70 from floor section 50 ( FIG. 12 ) i.e., a grid of intersecting incisions or cuts through the thickness of cushion material 56 so as to render it capable of being split into a plurality of separate and discrete pad segments. The bottom-most surface of each pad segment 70 is also pressed or embossed so as to define a plurality of lands 76 that are located between and separate a plurality of troughs or channels 77 that are arranged in regular intervals across the bottom surface of floor section 50 . In particular, bottom-most surface of each pad segment 70 is preferably formed by pressing or embossing the bottom-most surface of so as to compress portions of dividable cushion material layer 56 to form troughs or channels 77 while maintaining the portions of dividable cushion material layer 56 adjacent to troughs or channels 77 at or near to their original thickness so as to define lands 76 . Dividable cushion material layer 56 may additionally comprise a repositionable, pressure sensitive adhesive layer 80 substantially similar to repositionable, pressure sensitive adhesive layer 14 b ( FIG. 10 ) that is applied to the bottom-most surface of each pad segment 70 . Depending upon process conditions, repositionable, pressure sensitive adhesive layer 80 can be applied to the bottom surface of lands 26 as shown in FIGS. 8-24 , or it can be applied to the entire bottom surface of cushion layer 56 , including the surface that defines the bottom of channels 77 . Repositionable, pressure sensitive adhesive layer 80 advantageously adheres to a sub-floor surface with an initial tack that holds each pad segment 70 in place after application of a pressure, but allows for the removal of any one or more of pad segments 70 from the surface of the sub-floor absent a substantial diminution of an initial tack ( FIGS. 12, 13 , 14 , and 16 ).
[0061] Dividable cushion material layer 56 may comprise any one or a combination of soft, resilient materials including, but not limited to foamable polymers or foam such as chemical blown polyvinyl chloride plastisols/organosols, acrylics, rubber foams, polyurethane foams, froth foams such as polyvinyl chloride plastisol, acrylics, melt processed foams such as polyvinyl chloride, polyethylene, ethylene vinyl acetate, metallocene polyolefins, elastomeric polyolefin copolymers. Additionally, any soft, resilient or cushioned material which is foamed or non-foamed may also be employed. The thickness of dividable cushion material layer 56 and lands 76 is often about 0.5 mm to 3.0 mm, with those portions of dividable cushion material layer 56 that define troughs or channels 77 having an embossed thickness of about 1 mm or less.
[0062] Repositionable, pressure sensitive adhesive layer 80 is applied over the bottom-most surface of dividable cushion material layer 56 and is often curable, and functions as a releasable glue to hold floor section 50 in place on the sub-floor, while advantageously allowing floor section 50 (or one or more pad segments 70 ) to be removed, repositioned, and relayed onto the sub-floor. Repositionable, pressure sensitive adhesive layer 80 may be formed of rubber-type adhesives, acrylic adhesives, including e-beam curable acrylic adhesives, vinyl acetate-type adhesives, urethane-type adhesives, and combinations thereof, or any other pressure sensitive adhesives that are curable or non-curable as are well known in the art.
[0063] Floor section 50 may be applied to a sub-floor 85 in the following manner. Referring to FIGS. 11-24 , floor section 50 is applied to sub-floor 85 by first arranging dividable cushion material layer 56 in spaced confronting relation to the top surface of sub-floor 85 . Once in this position, floor section 50 is moved toward the top surface of sub-floor 85 until adhesive layer 80 engages the sub-floor. If sub-floor 85 is uneven, i.e., there are both depressions 87 ( FIGS. 21 and 22 ) and prominences 90 (FIGS. 23 and 24 ) within the sub-floor surface to be covered by floor section 50 , one or more pad segments 70 may be removed and/or stacked one atop another so as to compensate for the uneven surface features of the sub-floor. Of course, pad segments 70 would be removed from floor section 50 to form a complementary void 92 on its back surface so as to compensate for a prominence 90 that projects from the surface of sub-floor 85 . Alternatively, pad segments 70 from the same or any other floor section 50 , or as provided separately packaged, may be applied over top of other pad segments 70 on the back surface of floor section 50 so as to compensate for depressions 87 that are formed in the surface of sub-floor 85 ( FIGS. 17, 18 , 19 , and 20 ).
[0064] More particularly, one or more individual pad segments 70 may be peeled from backing layer 54 ( FIGS. 12, 13 , and 14 ) thereby creating a void 92 defined by the surrounding, remaining pad segments 70 adjacent to that section of dividable cushion material layer 56 . The number of pad segments 70 to be removed will correspond to the amount of surface area required to accept prominence 90 to be compensated for on the surface of sub-floor 85 ( FIGS. 23 and 24 ). In addition, the removed pad segments 70 may be stacked one atop another so as to build up the thickness in any region of dividable cushion material layer 56 so as to compensate for corresponding depressions 87 located on sub-floor 85 .
[0065] It is to be understood that the present invention is by no means limited only to the particular constructions herein disclosed and shown in the drawings, but also comprises any modifications or equivalents within the scope of the claims.
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A removable interior building surface-covering section member such as a floor tile, sheet, or plank is provided that can be laid without the use of adhesives and which can be removed and relayed repeatedly. The removable floor section member has multiple layers including an top surface, an intermediate cushion layer and a lower adhesive layer. The lower adhesive layer may have alternating raised and lowered channels to increase adhesion moisture conditions.
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PRIORITY AND RELATED APPLICATIONS
This application claims priority to International PCT Application No. PCT/FI2007/050256 entitled “Dual antenna” having an international filing date of May 8, 2007, which claims priority to Finland Patent Application No. 20065357 of the same title filed May 26, 2006, each of the foregoing incorporated herein by reference in its entirety. This application is related to co-owned and co-pending U.S. patent application Ser. No. 12/083,129 filed Apr. 3, 2008 entitled “Multiband Antenna System And Methods”, Ser. No. 12/080,741 filed Apr. 3, 2008 entitled “Multiband Antenna System and Methods”, Ser. No. 12/082,514 filed Apr. 10, 2008 entitled “Internal Antenna and Methods”, Ser. No. 12/009,009 filed Jan. 15, 2008 and entitled “Dual Antenna Apparatus And Methods”, Ser. No. 11/544,173 filed Oct. 5, 2006 and entitled “Multi-Band Antenna With a Common Resonant Feed Structure and Methods”, and co-owned and co-pending U.S. patent application Ser. No. 11/603,511 filed Nov. 22, 2006 and entitled “Multiband Antenna Apparatus and Methods”, each also incorporated herein by reference in its entirety. This application is also related to co-owned and co-pending U.S. patent application Ser. No. 11/648,429 filed Dec. 28, 2006 and entitled “Antenna, Component And Methods”, and Ser. No. 11/648,431 also filed Dec. 28, 2006and entitled “Chip Antenna Apparatus and Methods”, both of which are incorporated herein by reference in their entirety. This application is further related to U.S. patent application Ser. No. 11/901,611 filed Sep. 17, 2007 entitled “Antenna Component and Methods”, Ser. No. 11/883,945 filed Aug. 6, 2007entitled “Internal Monopole Antenna”, Ser. No. 11/801,894 filed May 10, 2007 entitled “Antenna Component”, and Ser. No. 11/922,976 entitled “Internal multiband antenna and methods” filed Dec. 28, 2007, each of the foregoing incorporated by reference herein in its entirety. This application is further related to U.S. patent application Ser. No. 12/082,882 filed Apr. 14, 2008 entitled “Adjustable Antenna and Methods”, and Ser. No. 12/217,789 filed Jul. 8, 2008 entitled “RFID Antenna and Methods”.
COPYRIGHT
A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever.
The invention relates to an antenna structure of a small-sized radio apparatus which structure comprises two electrically relatively separate parts.
In small-sized portable radio apparatuses, such as mobile phones, the antenna is placed for convenience of use preferably inside the covers of the apparatus. Furthermore, as one tries to make the antenna to consume as small a space as possible, its design becomes demanding. Additional difficulties in design are caused if the radio apparatus has to operate in several frequency ranges, the more the broader these ranges are.
Internal antennas are mostly plane-structured, whereby they have a radiating plane and a ground plane at a certain distance from it. A planar antenna can be made smaller by manufacturing the radiating plane on the surface of a dielectric substrate instead of it being air-insulated. Naturally, the higher the permittivity of the material, the smaller physically the antenna element having a certain electric size is. By using e.g. ceramics having a high dielectric constant as the substrate, the antenna component becomes a chip to be mounted on a circuit board. FIG. 1 shows an example of a dielectric antenna, or an antenna based on such a chip component. A portion of the circuit board PCB of a radio apparatus is seen in the figure. On the circuit board there is an antenna component 110 which comprises a dielectric substrate 111 and, on the surface of this, two antenna elements. The first antenna element 112 covers one portion of the top surface of the substrate and its one head surface. The second antenna element 113 covers another portion of the top surface of the substrate and its other, opposing head surface. The antenna elements extend a bit on the side of the bottom surface of the substrate for constituting contact surfaces. In the middle of the top surface between the elements, there is a slot SL which extends in the cross direction from one side surface of the substrate to another. The feed conductor 130 of the antenna is a strip conductor on the top surface of the circuit board, and it constitutes together with the ground plane, or the signal ground GND, and the circuit board material a feed line having a specified impedance. The feed conductor 130 connects galvanically to the first antenna element 112 on its contact surface. From its second contact surface, the first antenna element connects galvanically to the ground plane GND. At the opposing end of the substrate, the second antenna element 113 connects galvanically from its contact surface to the ground plane GND. The second antenna element only receives its feed electromagnetically over said slot SL, in which case it is a parasitic element.
The entire antenna consists of the antenna component 110 and the ground plane. In the example of FIG. 1 , there is no ground plane below the antenna component, and beside of the component the ground plane is at a certain distance from it. This distance and the width and length of the portion of the ground plane extending to the parasitic element 113 affect the natural frequency and the impedance of the entire antenna, for which reason the antenna can be tuned and matched by optimising them. The antenna elements radiate at least almost at the same frequency, the antenna thus being a one-band antenna.
A common way of realising a two- or multi-band antenna is to divide the radiating element to at least two branches of different lengths seen from the shorting point of the element. In this way, it is relatively easy to obtain a satisfying result in air-insulated planar antennas. Instead, when using a very small-sized chip component, it is difficult to obtain reasonable matching with e.g. two operating bands. Furthermore, isolation between the antenna components corresponding to different bands remains inadequate.
FIG. 2 shows a known dielectric antenna in which some afore-mentioned disadvantages are eliminated. The structure is a dual antenna; it includes two antenna components with a ceramic substrate on a circuit board PCB and the partial antennas corresponding them. The antenna structure has a lower and an upper resonance, and it has correspondingly two bands: the lower operating band is constituted by the first antenna component 210 , and the upper operating band by the second antenna component 220 . Because of the separateness of the components, also their electromagnetic near fields are separate, and the isolation between the partial antennas is good in this relation. The partial antennas have a shared feed conductor 231 connected to the antenna port AP, which feed conductor branches to feed conductors leading to the antenna components. If these feed conductor branches were connected directly to the radiators, the partial antennas would adversely affect each other via their shared feed so that the tuning of one would change the tuning of the other. Furthermore, the upper resonance would easily become weak or it would not excite at all. For this reason, the structure requires matching components. In the example of FIG. 2 , in series with the feed conductor of the first antenna component 210 are a coil L 1 and a capacitor C 1 . The natural frequency of the resonance circuit constituted by these is the same as the centre frequency of the lower operating band. In series with the feed conductor of the second antenna component 220 is a capacitor C 2 , and between its end on the side of the antenna component and the ground plane GND is a coil L 2 . The cut-off frequency of a high-pass filter constituted by the capacitor C 2 and the coil L 2 is somewhat below the upper operating band.
A disadvantage of the solution according to FIG. 2 and similar other arrangements is the space required by the matching components on the circuit board and additional costs in production incurred by them. It is conceivable that the required matching is made without separate components with conductor patterns on the surface of the circuit board, but in any case all these patterns would require a relatively large area on the circuit board.
In a first aspect of the invention, a dielectric antenna comprising a dual antenna is disclosed. In one embodiment, the dual antenna comprises one partial antenna of which is implemented the lower operating band of the antenna and with the other partial antenna the upper operating band. The partial antennas have a shared feed point in the antenna structure, e.g. at an end of a radiating element of one partial antenna, in which case the other partial antenna receives its feed galvanically through said radiating element by a short intermediate conductor. The partial antennas are located so that their substrates are heads face to face, and the main directions of the radiating elements i.e. the conductive coatings of the substrates starting from the shared feed point are opposing.
An advantage of this exemplary embodiment of the invention is that the tunings of partial antennas corresponding to the different operating bands are obtained independent from each other without discrete matching components, even though they have a shared feed point. Related to foregoing, an advantage of this exemplary embodiment of the invention is that the space required for the antenna structure is very small. A further advantage of this exemplary embodiment of the invention is that the efficiency of the antenna is good for a dielectric antenna.
In a second aspect of the invention, a dual antenna is disclosed. In one embodiment, the dual antenna comprises a radiating element disposed on a first portion of a first substrate; a radiating element disposed on a second portion of a second substrate; a feed point common to both the first and second radiating elements; and an intermediate conductor disposed between the first radiating element and the second radiating element.
In one variant, the feed point common to both the first and second radiating elements is in the first radiating element.
In another variant, the first substrate and the second substrate are substantially detached from one another.
In still another variant, the first and second substrates are part of a unitary substrate, and at least a portion of the material of the unitary substrate has been removed between the first and second radiating elements to provide at least some electrical isolation.
In yet another variant, the intermediate conductor comprises a conductive coating on a surface of the substrate, the intermediate conductor extending from the first radiating element to the second radiating element.
In still another variant, the intermediate conductor comprises a conductive coating disposed on an inner surface of a hole formed in the substrate, the conductive coating extending from the first radiating element to the second radiating element.
In still yet another variant, the substrate comprises a ceramic material.
In a second embodiment, the dual antenna comprises a first partial antenna to implement a lower operating band of the antenna; and a second partial antenna to implement an upper operating band; wherein both partial antennas comprise a respective dielectric substrate and as its conductive coating at least one radiating element, wherein both substrates have a first and a second head, a top, a bottom and a plurality of side surfaces the direction of the plurality of side surfaces normal of the heads being the longitudinal direction of the substrate. The substrates of the partial antennas are located their first heads face to face, they have substantially the same longitudinal direction, and the partial antennas have a shared feed point in a coupling space defined by the first heads at the end of the radiating element on the side of the first head of the substrate of one partial antenna. The other partial antenna gets its feed through an intermediate conductor which extends in the coupling space from last-mentioned radiating element to a radiating element of the latter partial antenna.
In one variant, the shared feed point is in a radiating element of the first partial antenna.
In another variant, the substrate of the first partial antenna and the substrate of the second partial antenna are detached, and the intermediate conductor is a separate conductor connected to a radiator of the first partial antenna and a radiator of the second partial antenna.
In another variant, the substrate of the first partial antenna and the substrate of the second partial antenna constitute a unitary total substrate, where substrate material has been reduced between the partial antennas for improving their electrical isolation.
In still another variant, the intermediate conductor is a conductive coating on inner surface of the type of hole, the coating extending from the radiator of the first partial antenna to the radiator of the second partial antenna.
In yet another variant the substrate material has been reduced so that at least one hole leads through the substrate.
In another variant, the substrate material has been reduced so that there is at least one groove in the substrate.
In still yet another variant, the intermediate conductor is a conductive coating on a side surface of the substrate extending from a radiator of the first partial antenna to a radiator of the second partial antenna.
In another variant, the first partial antenna comprises a first radiating element which covers one part of the top surface of its substrate and at least a part of the first head of its substrate, and a second radiating element which covers another part of the top surface of the substrate in question and at least a part of the other head of the substrate. The radiating elements extend via the heads of the substrate on the side of the bottom surface of the substrate to form the feed point and a ground point to the first radiating element and to form at least one ground point to the second radiating element.
In yet another variant, the substrates comprise a ceramic material.
In a third embodiment, the dual antenna comprises an independently-tunable dual antenna, the antenna being disposed on an external substrate and comprising: a first radiating element disposed on a first substrate; a second radiating element disposed on a second substrate; a feed point common to both the first and second radiating elements; an intermediate conductor disposed between the first radiating element and the second radiating element; and a conductive trace on the external substrate electrically coupled with the feed point. The independent tuning is provided at least in part by way of the intermediate conductor and without the use of discrete matching components.
In a third aspect of the invention a method of operating a dual antenna is disclosed. In one embodiment, the dual antenna is capable of operating in first and second frequency bands and the antenna comprises a first radiating element disposed on a first substrate, a second radiating element disposed on a second substrate, a feed point common to both the first and second radiating elements; and an intermediate conductor disposed between the first radiating element and the second radiating element, the dual antenna being disposed on an external substrate different from the first or second substrates. The method comprises placing a conductive trace on the external substrate in signal communication with the feed point of the dual antenna; and operating the dual antenna within the first and second bands.
In one variant, the method further comprises tuning the first and second radiating elements substantially independent of one another.
In another variant, the substantially independent tuning of the first and second radiating elements is provided at least in part by the intermediate conductor.
In still another variant, the method further comprises providing electrical isolation between the first and second radiating elements, the isolation provided at least in part by use of the first substrate and the second substrate, the first and second substrates being substantially detached from one another.
In another variant, the method further comprises providing electrical isolation between the first and second radiating elements, the isolation provided at least in part by the first and second substrates, the first and second substrates comprise a unitary substrate having material removed at least partly between the first and second radiating elements, the removed material enhancing the electrical isolation between the first and second radiating elements.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in detail. The description refers to the accompanying drawings in which
FIG. 1 shows an example of a known dielectric antenna,
FIG. 2 shows an example of a known dielectric dual antenna,
FIG. 3 shows an example of a dielectric dual antenna according to the invention,
FIG. 4 shows a second example of a dielectric dual antenna according to the invention,
FIG. 5 shows a third example of a dielectric dual antenna according to the invention, and
FIG. 6 shows an example of the efficiency of an antenna according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference is now made to the drawings wherein like numerals refer to like parts throughout.
FIGS. 1 and 2 were already described in connection with the description of prior art.
FIG. 3 shows an example of a dielectric dual antenna according to the invention. A portion of the circuit board PCB of a radio apparatus is seen in the drawing. On the circuit board there are two antenna components 310 and 320 , as in FIG. 2 . These components will be called “partial antennas”. Both partial antennas comprise a dielectric substrate which has heads, top and bottom surfaces and side surfaces. The substrates are located heads face to face relatively close to each other and they have the same longitudinal direction, when this means the direction of the normal of the heads. The face-to-face located heads of the substrates will be called first heads. The first partial antenna 310 further comprises on the surface of its substrate 311 in this example two radiating elements: the first radiating element 312 covers one portion of the top surface of the substrate 311 and its first head at least partially, and the second radiating element 313 covers another portion of the top surface of the substrate 311 and its second head at least partially. The radiating elements extend via the heads a bit to the side of the bottom surface of the substrate in the corners of the bottom surface for constituting the contact surfaces. The first radiating element is connected from its first contact surface 316 to the feed conductor 331 of the antenna and from the second contact surface to the ground GND. The second radiating element 313 is parasitic being connected from its both contact surfaces 318 , 319 to the ground GND. The parts of the antenna corresponding to the first and the second radiating element have the same resonance frequency. The second partial antenna 320 further comprises on the surface of its substrate 321 in this example one radiating element. This element, or the third radiating element 322 , covers at least partially the top surface of the second substrate 321 and both its first and second head.
Because of the mutual position of the substrates, the main direction of the radiating elements of the first partial antenna and the main direction of the radiating element of the second partial antenna are opposing seen from the shared feed point.
The feed conductor 331 of the antenna is a conductor strip on the top surface of the circuit board PCB. The feed conductor 331 extends below the first partial antenna 310 at the end on the side of the first head of the first substrate 311 and is connected as described above to the first radiating element 312 on its contact surface 316 in the corner of the bottom surface of the substrate 311 . This point in the first radiating element is the shared feed point FP of the partial antennas. It is located according to the invention between the partial antennas in a so-called coupling space. The “coupling space” means in this description and claims the space substantially of the shape of a rectangular prism defined by the first heads of the substrates and extended a little to both directions in all three dimensions. “A little” means a distance which is small compared to the length and width of the substrates.
The second partial antenna 320 gets its feed through a short intermediate conductor 332 , one end of which is connected to the first radiating element 312 at the first head of the first substrate 311 and other end of which is connected to the third radiating element 322 at the first head of the second substrate 321 . The intermediate conductor is thus in the coupling space. The third radiating element is connected galvanically only to the intermediate conductor 332 , the second partial antenna then being in this example of monopole type. The first and the second partial antenna and the intermediate conductor together constitute the dual antenna 300 .
FIG. 4 shows a second example of a dielectric dual antenna according to the invention. The dual antenna 400 comprises the first partial antenna which includes its substrate 411 , the first radiating element 412 and the second radiating element 413 and the second partial antenna which includes its substrate 421 and the third radiating element 422 , as in FIG. 3 . A difference to the structure shown in FIG. 3 is that said substrates 411 , 421 constitute now a unitary total substrate 440 . Therefore, in this case the substrates of the partial antennas are called partial substrates. The partial substrates are separated from each other with two holes HL 1 , HL 2 extending through the substrate 440 from its top surface to its bottom surface. These holes are elongated in the cross direction of the substrate so that only three relatively narrow necks join the partial substrates to each other. For this reason, the field of both partial antennas can spread in the substrate only to a small extent to the side of the other antenna, and the electrical isolation of the partial antennas is thus relatively good.
In FIG. 4 , the dual antenna 400 has been drawn from above and in the other sub-figure along a longitudinal line A-A one side cut away as far as the first hole HL 1 . Thus the narrow rear portion of the inner surface of the first opened hole HL 1 is seen in the latter sub-figure, which rear portion joins from its one edge the first head of the first partial substrate 411 and from its other edge the first head of the second partial substrate 421 . These heads are coated with conductive material so that the first radiating element 412 extends via holes HL 1 and HL 2 on the bottom surface of the substrate, and the third radiating element 422 extends via the opposing surfaces of the same holes to a certain distance from the bottom surface of the substrate. The afore-mentioned rear portion of the inner surface of the first hole HL 1 is partially coated with conductive material. This conductive coating 432 connects the third radiating element to the first radiating element thus functioning as the intermediate conductor feeding the second partial antenna. The intermediate conductor 432 is in the coupling space of the antenna 400 . The intermediate conductor could also be on the top surface of the substrate 411 between the holes HL 1 and HL 2 .
The sectional drawing of FIG. 4 shows a contact surface 417 being the one further back of the contact surfaces of the first radiating element 412 on the bottom surface of the substrate. This can be connected either to the feed conductor of the antenna or the signal ground. Likewise is seen a contact surface 419 being the one further back of the contact surfaces of the parasitic second radiating element 413 , which contact surface is connected to the signal ground.
FIG. 5 shows a third example of a dielectric dual antenna according to the invention. The dual antenna 500 has been drawn both from above and sideways. It comprises the first partial antenna which includes its substrate 511 , the first radiating element 512 and the second radiating element 513 and the second partial antenna which includes its substrate 521 and the third radiating element 522 , as in previous figures. The substrate of the first partial antenna, or the first partial substrate 511 and the substrate of the second partial antenna, or the second partial substrate 521 , constitute a unitary total substrate 540 , as in FIG. 4 . The partial substrates are in this case separated from each other by three holes HL 1 , HL 2 , HL 3 extending vertically through the substrate 540 and by two grooves CH 1 , CH 2 . The first groove CH 1 is at the holes downwards from the top surface of the substrate and the second groove CH 2 is at the holes upwards from the bottom surface of the substrate. Thus, four relatively narrow necks, the height of which is notably smaller than the height of the substrate, remain to connect the partial substrates. In this way, the electrical isolation of the partial antennas is arranged relatively good.
A most notable difference to the structure shown in FIG. 4 is that an intermediate conductor 532 feeding the second partial antenna is now on one side surface of the substrate 540 . This side surface is coated with conductor so that the opposing ends of the first radiating element 512 and the third radiating element 522 become coupled to each other. In this case, the intermediate conductor 532 has to go round the end of the first groove thus forming a U-shaped bend.
The feed point FP of the dual antenna 500 is also in this case on the bottom surface of the substrate 540 on the side of the first partial substrate 511 in the coupling space of the antenna. The feed point is connected galvanically to the part of the first radiating element 512 on the top surface of the substrate via the conductive coating of the first hole HL 1 .
FIG. 6 shows an example of the efficiency of an antenna according to FIG. 3 . The curve shows the efficiency as a function of frequency. The lower operating band of the antenna is tuned to the receive band of the GSM900 (Global System for Mobile communications) system and the upper operating band to the receive band of the GSM1900 system. It is seen that the efficiency in the lower band is on average about 0.35 and in the upper band about 0.45. Thus, the efficiency is good especially in the upper band considering the small size of the antenna.
In this description and claims a “partial antenna” means a pure chip component, which comprises radiators, or a portion of it. Correspondingly, an “antenna” means the combination of “partial antennas”. Functionally, the antenna also comprises the ground arrangement around the chip component(s). Prefixes “bottom”, “top”, “horizontal” and “vertical” and epithets “below”, “above” and “from above” refer to the position of the antenna in which it is mounted on the top surface of a horizontal circuit board. The operating position of the antenna can naturally be whichever.
An antenna according to the invention can naturally differ in its details from the ones described. For example, the feed conductor of the antenna can be connected to the partial antenna corresponding to the upper operating band instead of the partial antenna corresponding to the lower operating band. The location of the intermediate conductor connecting partial antennas to each other can vary in the coupling space of the antenna. The partial antenna corresponding to the lower operating band can comprise only one radiator instead of two, and the partial antenna corresponding to the upper operating band can comprise two radiators instead of one. In addition to its feed point, an individual radiator can also be connected to the ground. If the antenna has a unitary substrate, the number and shape of the holes separating the partial substrates can vary. They can also lead horizontally through the substrate. In addition to holes or instead of them, there can be grooves separating partial substrates. The intermediate conductor connecting the partial antennas to each other can be on the surface of a hole or a groove or on the outer surface of the entire substrate irrespective of how the reduction of the substrate material improving the electrical isolation of the partial antennas has been implemented. Manufacturing an antenna according to the invention can be implemented e.g. by coating a ceramic chip partially with a conductor or by growing a metal layer on the surface of e.g. silicon and removing a portion of it with a technology used in manufacturing of semiconductor devices. The inventive idea can be applied in different ways within the limitations set by the independent claim 1 .
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A dielectric dual antenna ( 300 ) intended especially for small-sized radio apparatuses, with one partial antenna ( 310 ) of which is implemented the lower operating band of the antenna and with the second partial antenna ( 320 ) the upper operating band. The partial antennas have a shared feed point (FP) in the antenna structure, e.g. at the end of a radiating element ( 312 ) of one partial antenna, in which case the other partial antenna receives its feed galvanically through said radiating element by a short intermediate conductor ( 332 ). The partial antennas are located so that their substrates ( 311, 321 ) are heads face to face, and the main directions of the radiating elements i.e. the conductive coatings of the substrates starting from the shared feed point are opposing. The tunings of the partial antennas corresponding to different operating bands are obtained independent from each other without discrete matching components.
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BACKGROUND OF THE INVENTION
Diesel engines operate by compression ignition. They have compression ratios in the range of 14:1 to 17:1 or higher and for that reason obtain more useful work from a given amount of fuel compared to a spark-ignited engine. Historically, diesel engines have been operated on a petroleum-derived liquid hydrocarbon fuel boiling in the range of about 300°-750° F. Recently, because of dwindling petroleum reserves, alcohol and alcohol-hydrocarbon blends have been studied for use as diesel fuel.
One major factor in diesel fuel quality is cetane number. Cetane number is related to ignition delay after the fuel is injected into the combustion chamber. If ignition delay is too long, the amount of fuel in the chamber increases and upon ignition results in a rough running engine and increased smoke. A short ignition delay results in smooth engine operation and decreases smoke. Commercial petroleum diesel fuels generally have a cetane number of about 40-55. Alcohols have a much lower cetane value and require the addition of a cetane improver for successful engine operation.
Through the years, many types of additives have been prepared to raise the cetane number of diesel fuel. These include peroxides, nitrites, nitrates, nitrocarbamates, and the like. Alkyl nitrates such as amyl nitrate, hexyl nitrate and mixed octyl nitrates have been used commercially with good results. Likewise, certain cyclohexyl nitrates and alkoxyalkyl nitrates have been suggested as cetane improvers for diesel fuel (Olin et al., U.S. Pat. No. 2,294,849).
Unfortunately some compounds that are very effective cetane improvers are also fairly sensitive explosives. Because of this they have not found commercial acceptance. Attempts have been made to desensitize some of these explosive compounds by blending with inert solvents. However, such blends are much less effective than the original compound and would require shipping and storing large amounts of cetane improver additive to provide the required cetane boost.
U.S. Ser. No. 479,508, entitled "Desensitized Cetane Improvers", filed Mar. 28, 1983, discloses that normally explosion sensitive cetane improvers can be desensitized by blending with C 5 -C 12 alkyl nitrates to provide a blend of cetane improvers that is both safe and effective.
SUMMARY OF THE INVENTION
It has now been discovered that normally explosion sensitive cetane improvers can be desensitized by blending with nitric acid esters of bicyclic or tricyclic alcohols containing four-membered or five-membered rings to provide a blend of cetane improvers that is both a safe and effective cetane additive.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of the invention is a desensitized cetane improver for use in diesel fuel, said cetane improver comprising a mixture of (a) at least one compound having a 50% explosion Drop Weight Rating of less than 20 Kg centimeters (cms) as measured by ASTM Method D-2540 and being capable of giving a greater cetane increase than an equal amount of any C 5 to C 12 alkyl nitrate, and (b) a nitric acid ester of a bicyclic or tricyclic alcohol containing a four-membered or a five-membered ring in an amount sufficient to increase the ASTM D-2540 rating of the mixture to a value of at least 40 Kg centimeters (cms).
Explosive sensitivity is measured using the ASTM D-2540. This method is substantially the same as the Olin Matheson Drop Weight Test. It is routinely used to rate explosion sensitivity of liquid rocket mono-propellants. In this test, the test sample is placed in a small cavity formed by a steel cup. In the cup is placed an elastic ring and a steel diaphram on top of the elastic ring. A piston rests on the diaphram. The piston has a vent hole which is blocked by the steel diaphram. A weight is dropped on the piston. Explosion is indicated by puncture of the diaphram and a loud report. The sensitivity is the energy required to cause an explosion fifty percent of the time. This energy is the product of the drop weight and height of drop and is expressed as Kilogram centimeters (Kg cms). The lower this value is, the more explosion sensitive the test additive. A typical value for sensitive compounds such as nitroglycerin, ethyl nitrate and diethylene glycol dinitrate is 2 Kg-cms. Normal propyl nitrate rates about 15.5 Kg-cm.
Component (a) of the mixture will have a 50% explosion ASTM D-2540 rating of less than 20 Kg cm and also have a cetane improving effectiveness which is greater than that of an alkyl nitrate containing 5-12 carbon atoms. Thus, whether a compound qualifies as a component (a) additive is readily determined by conducting an ASTM D-2540 Drop Weight Test and measuring its cetane improving effectiveness on a weight basis using a standard cetane engine compared to amyl nitrate, hexyl nitrates, heptyl nitrates, octyl nitrates, decyl nitrates or dodecyl nitrates.
Representative explosion sensitive compounds include the C 1-3 alkyl nitrates such as methyl nitrate, ethyl nitrate, n-propyl nitrate and isopropyl nitrate.
Organic polynitrates containing about 2-6 carbon atoms and 2-6 nitrate groups are useful such as glycol dinitrate, nitroglycerine, mannitol tetranitrate, trimethylolpropane trinitrate, pentaerythritol tetranitrate, propylene glycol dinitrate, 1,4 butanediol dinitrate, and the like.
Many ether nitrates are sensitive explosives such as diethylene-glycol dinitrate, triethyleneglycol, dinitrate, tetraethyleneglycol dinitrate, tetrahydro-3-furanol nitrate, 2-ethoxyethyl nitrate, 2-methoxyethyl nitrate, tetrahydro-3,4-furandiol dinitrate and the like.
Of the foregoing, the more preferred ether nitrates are those having the formula
R.sub.1 --OR.sub.2 --.sub.n ONO.sub.2
or
O.sub.2 N--OR.sub.3 --.sub.m ONO.sub.2
wherein R 1 is a C 1-4 alkyl, R 2 and R 3 are C 2-4 divalent aliphatic hydrocarbon radicals and n is an integer from 1 to 4 and m is an integer from 2 to 4.
Organic nitro-nitrate compounds containing about 3-6 carbon atoms are likewise very effective cetane improving compounds that are also sensitive to explosion. These include compounds having the formula ##STR1## in which R is an aliphatic hydrocarbon group containing 3-6 carbon atoms and p and q are integers independently selected from 1 and 2.
Representative examples of these compounds are 2,2-dinitro-propanol nitrate, 2-methyl-2-nitropropyl nitrate, 2-ethyl-2-nitro-1,3-propanediol dinitrate, 2-methyl-2-nitro-1,3-propanediol dinitrate, 2,2-dinitro-1,6-hexanediol dinitrate, 2,2-dinitrobutanol nitrate and the like.
Component (b) in the mixture is a nitric acid ester of a bicyclic or tricyclic alcohol containing a four-membered or five-membered ring such as norbornyl nitrate, isobornyl nitrate, pinene nitrate, 5,6-cyclopenteno-2-norbornyl nitrate, 5,6-cyclopenteno-3-norbornyl nitrate and 5,6-cyclopentano-2-norbornyl nitrate. Most preferably component (b) is 5,6-cyclopenteno-2-norbornyl nitrate. These compounds and methods for their preparation are disclosed in British 1,196,167 incorporated herein by reference.
The amount of component (b) in the blend should be an amount that reduces the explosion sensitivity of the mixture to an ASTM D-2540 rating above about 20 Kg cm. More preferably, the amount of component (b) will be sufficient to increase the rating above about 40. Depending upon the degree of de-sensitizing required, the amount of component (b) can range from 10-90 weight percent of the mixture. Generally, the amount of (b) will be 25-75 weight percent. Excellent results have been achieved with 50--50 mixtures.
Representative examples of blends are given in the following table:
______________________________________Component A Component B______________________________________30% ethylene glycol dinitrate 70% 5,6-cyclopenteno- 2-norbornyl nitrate50% diethylene glycol dinitrate 50% 5,6-cyclopenteno- 2-norbornyl nitrate10% 2-methoxyethyl nitrate 90% 5,6-cyclopenteno- 2-norbornyl nitrate40% 2-ethoxyethyl nitrate 60% 5,6-cyclopenteno- 2-norbornyl nitrate60% 2-butoxyethyl nitrate 40% 5,6-cyclopenteno- 2-norbornyl nitrate10% nitroglycerine 90% 5,6-cyclopenteno- 2-norbornyl nitrate15% trimethylol propane trinitrate 85% 5,6-cyclopenteno- 2-norbornyl nitrate50% tetrahydro-3-furanol nitrate 50% 5,6-cyclopenteno- 2-norbornyl nitrate30% 2-nitro-2-methylpropyl nitrate 70% 5,6-cyclopenteno- 2-norbornyl nitrate35% 2,2-dinitrobutyl nitrate 65% 5,6-cyclopenteno- 2-norbornyl nitrate30% ethylene glycol dinitrate 70% 5,6-cyclopenteno- 3-norbornyl nitrate50% diethylene glycol dinitrate 50% 5,6-cyclopenteno- 3-norbornyl nitrate10% 2-methoxyethyl nitrate 90% 5,6-cyclopenteno- 3-norbornyl nitrate40% 2-ethoxyethyl nitrate 60% 5,6-cyclopenteno- 3-norbornyl nitrate60% 2-butoxyethyl nitrate 40% 5,6-cyclopenteno- 3-norbornyl nitrate10% nitroglycerine 90% 5,6-cyclopenteno- 3-norbornyl nitrate15% trimethylol propane trinitrate 85% 5,6-cyclopenteno- 3-norbornyl nitrate50% tetrahydro-3-furanol nitrate 50% 5,6-cyclopenteno- 3-norbornyl nitrate30% 2-nitro-2-methylpropyl nitrate 70% 5,6-cyclopenteno- 3-norbornyl nitrate35% 2,2-dinitrobutyl nitrate 65% 5,6-cyclopenteno- 3-norbornyl nitrate30% ethylene glycol dinitrate 70% 5,6-cyclopenteno- 3-norbornyl nitrate50% diethylene glycol dinitrate 50% 5,6-cyclopenteno- 3-norbornyl nitrate10% 2-methoxyethyl nitrate 90% 5,6-cyclopenteno- 3-norbornyl nitrate40% 2-ethoxyethyl nitrate 60% 5,6-cyclopenteno- 3-norbornyl nitrate60% 2-butoxyethyl nitrate 40% 5,6-cyclopenteno- 3-norbornyl nitrate10% nitroglycerine 90% 5,6-cyclopenteno- 3-norbornyl nitrate15% trimethylol propane trinitrate 85% 5,6-cyclopenteno- 3-norbornyl nitrate50% tetrahydro-3-furanol nitrate 50% 5,6-cyclopenteno- 3-norbornyl nitrate30% 2-nitro-2-methylpropyl nitrate 70% 5,6-cyclopenteno- 3-norbornyl nitrate35% 2,2-dinitrobutyl nitrate 65% 5,6-cyclopenteno- 3-norbornyl nitrate30% ethylene glycol dinitrate 70% norbornyl nitrate50% diethylene glycol dinitrate 50% norbornyl nitrate10% 2-methoxyethyl nitrate 90% norbornyl nitrate40% 2-ethoxyethyl nitrate 60% norbornyl nitrate60% 2-butoxyethyl nitrate 40% norbornyl nitrate10% nitroglycerine 90% norbornyl nitrate15% trimethylol propane trinitrate 85% norbornyl nitrate50% tetrahydro-3-furanol nitrate 50% norbornyl nitrate30% 2-nitro-2-methylpropyl nitrate 70% norbornyl nitrate35% 2,2-dinitrobutyl nitrate 65% norbornyl nitrate30% ethylene glycol dinitrate 70% pinene nitrate50% diethylene glycol dinitrate 50% pinene nitrate10% 2-methoxyethyl nitrate 90% pinene nitrate40% 2-ethoxyethyl nitrate 60% pinene nitrate60% 2-butoxyethyl nitrate 40% pinene nitrate10% nitroglycerine 90% pinene nitrate15% trimethylol propane trinitrate 85% pinene nitrate50% tetrahydro-3-furanol nitrate 50% pinene nitrate30% 2-nitro-2-methylpropyl nitrate 70% pinene nitrate35% 2,2-dinitrobutyl nitrate 65% pinene nitrate______________________________________
It is indeed surprising that the addition of a compound which is itself an organic nitrate as well as an effective cetane improver to an otherwise explosive nitrate would have such a substantial effect on decreasing sensitivity.
ASTM D-2540 Drop Weight Tests were conducted to measure the de-sensitizing effect of the added organic nitrate. In these tests, an otherwise very sensitive compound, 2-nitro-2-methylpropyl nitrate, was blended with 5,6-cyclopenteno-2-norbornyl nitrate to decrease sensitivity. This compound alone is more effective as a cetane improver than any C 5-12 alkyl nitrate but is quite prone to explode in the Drop Weight Test. The Drop Weight results are given in the following table.
______________________________________Additive Drop Weight Rating______________________________________1. 2-nitro-2-methylpropyl nitrate 10 Kg cm2. 2-nitro-2-methylpropyl nitrate + 24 Kg cm 25 wt. % 5,6-cyclo- penteno-2-norbornylnitrate3. 2-nitro-2-methylpropyl nitrate + 57 Kg cm 50 wt. % 5,6-cyclo- penteno-2-norbornylnitrate4. 2-nitro-2-methylpropyl nitrate + 120 Kg cm 50 wt. % 5,6-cyclo- penteno-2-norbornylnitrate______________________________________
These results show that blending the explosion sensitive organic nitrates with a component (b) organic nitrate results in a substantially de-sensitized composition. The de-sensitizing effect provided by the invention is not necessarily applicable to thermal stability so, as with any organic nitrate, the mixtures should not be heated.
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Compounds that are themselves effective cetane improvers in diesel fuel but are considered too explosion sensitive for safe handling can be rendered relatively nonsensitive by blending with nitric acid esters of bicyclic or tricyclic alcohols containing a four-membered or five-membered ring and the resulting blend is an effective cetane improver. An example is a 50-50 blend of 2-methyl-2-nitropropyl nitrate, a shock-sensitive compound, with 5,6-cyclopenteno-2-norbornyl nitrate to give a relatively insensitive, but very effective cetane improver.
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FIELD OF THE INVENTION
The present invention relates generally to papermakers' fabrics and more specifically to methods of manufacturing papermakers' felts.
BACKGROUND OF THE INVENTION
In the conventional fourdrinier papermaking process, a water slurry, or suspension, of cellulosic fibers (known as the paper “stock”) is fed onto the top of the upper run of an endless belt of woven wire and/or synthetic material that travels between two or more rollers. The belt, often referred to as a “forming fabric,” provides a papermaking surface on the upper surface of its upper run which operates as a filter to separate the cellulosic fibers of the paper stock from the aqueous medium, thereby forming a wet paper web. The aqueous medium drains through mesh openings of the forming fabric, known as drainage holes, by gravity alone or with assistance from one or more suction boxes located on the lower surface (i.e., the “machine side”) of the upper run of the fabric.
After leaving the forming section, the paper web is transferred to a press section of the paper machine, in which it is passed through the nips of one or more pairs of pressure rollers covered with another fabric, typically referred to as a “press felt.” Pressure from the rollers removes additional moisture from the web; the moisture removal is often enhanced by the presence of a “batt” layer on the press felt. The paper is then conveyed to a drier section for further moisture removal. After drying, the paper is ready for secondary processing and packaging.
Press felts typically include two components: a base fabric and one or more batt layers. The base fabric is typically a woven construction that includes cabled or single monofilaments, plied multifilaments, or spun yarns. In a press felt, the base fabric may be a single layer fabric, an interwoven multilayer fabric, or a laminated construction comprising two or more distinct and separate fabric layers. The weave pattern(s) and yarn sizes and configurations employed in the base fabric are selected for the desired performance of the fabric; in particular, the fabric is designed for a desired balance of properties that include pressure uniformity, flow resistance, void volume, and compressibility.
The batt layer(s) of a fabric typically comprise staple fibers (usually synthetic fibers, such as nylon or polyester) that are applied in overlying layers to the base fabric. The thickness, denier and material of the batt fibers are typically selected for their contribution to the desired performance properties of the overall press felt.
In the typical manufacture of a press felt, batt fibers are “carded” to form a uniform web, then needled from this web into the base fabric. In the needling process, the batt web and base fabric are fed into a needle loom, where many needles (often on the order of 1,000-4,000 needles per lineal meter) are employed to insert the batt fibers into the base fabric. Conventionally, the needles are mounted in an industry standard “random” pattern on a needle board. The needle board is mounted on a needle beam, which in turn is mounted on the loom so that it can move in a reciprocating path in a direction normal to the batt web and fabric. Most commonly, the needles are of a “reverse-barb” configuration which snags batt fibers when moving in a direction toward the batt web and base fabric (ie., during insertion segment of the needle stroke) but fails to snag fibers when moving away from the batt and fabric (i.e., during the retraction segment of the needle stroke). Thus, as the needles are inserted through the batt and into the base fabric, the barbs of the needles engage the fibers of the batt web and thread them into the interstices of the base fabric. The needles can be retracted from the base fabric and batt web without the barbs snagging the batt fibers.
Generally, a press felt undergoes multiple passes through a needling loom, some of which may be conducted with different needle penetration depths, needle configurations, and fabric advance rates, and some of which simply involve the insertion of the needles into the base fabric without the addition of more batt fibers (when no additional batt fiber is applied, the needling typically serves to further engage batt fiber already present on the base fabric and reduce the thickness of the batt layer). Once needling is complete, the press felt is usually then subjected to some post-needling steps, such as heat setting, washing and singeing.
As noted above, during the needling process the needle board upon which the needles are mounted reciprocates along a path normal to the batt and fabric. The fabric and batt are advanced between needle strokes, either continuously (which is preferred for manufacturing efficiency) or intermittently, into position for subsequent needling.
Although continuous advancing of the batt and fabric is preferred for increased needling rate, this process can be deleterious for the finished press felt product, and in particular for the base fabric. The continuous motion of the base fabric can cause portions of the base fabric (especially the yarns of the base fabric that extend in a direction normal to the direction the fabric is moving) to contact and exert bending forces on the inserted needle. This interaction with the needle causes the yarns of the fabric to alternately stretch and compress in localized regions around each needle. Not only are the yarns of the base fabric stretched and compressed, the batt overlying these regions can become bunched or thinned. These heterogeneous regions of the press felt can adversely affect the smoothness and uniformity of the paper processed with the press felt. Also, the barbs of the needles can rub against the yarns of the fabric and have a “sawing” effect that may cut or weaken the yam. All of these effects can negatively impact the performance and consistency of the press felt during operation.
SUMMARY OF THE INVENTION
These and other objects are satisfied by the present invention, which is directed to a method of forming a papermakers' felt that reduces the risk of damaging the base fabric and batt thereof. The method first comprises providing a needle loom having a needle board, a plurality of needles mounted on the needle board, and a needle motion unit. The needle motion unit moves the needle board such that the needles mounted thereon travel on a predetermined path that includes upward and downward segments, wherein each of the upward and downward segments includes both forward and rearward motion. The method then comprises the step of continuously conveying a base fabric and a batt web overlying the base fabric in a first direction past the needle board. The base fabric includes a first set of machine direction yarns and a first set of cross machine direction yarns interwoven with the first set of machine direction yarns in a predetermined repeating pattern, and the batt web comprises batt fibers. The next step of the method is inserting batt fibers from the batt web into the base fabric with the plurality of needles as the base fabric is conveyed past the needle board and as the needle board travels along the predetermined path to form a batt layer attached to and overlying the base fabric. This method can reduce or eliminate the negative effects on press felts discussed hereinabove.
The method is particularly well-suited for press felts in which the base fabric includes fine yarns. In one preferred embodiment, the base fabric includes cabled, plied machine and cross machine direction yarns formed of individual monofilaments having a diameter of between about 0.1 and 0.3 mm.
The method can also be practiced by determining the positions of the yarns within the base fabric, performing the step of inserting the yarns as described above responsive to the positions of the yarns, then performing a second inserting step responsive to the positions of the yarns. Because the method has the effect of reducing the degree to which yarns are displaced during needling, more precise and accurate needling is possible.
The method of the present invention can also be practiced by inserting batt fiber at an oblique angle to the base fabric. This may be carried out by passing the base fabric and batt web over a needle bed that is obliquely disposed relative to the general direction of needle travel. Under this method, the batt fibers of the batt layer can become anchored more firmly within the base fabric than in prior art press felts thereby improving the performance and durability of the press felt.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a section view of a press felt formed with the method of the present invention.
FIG. 2 is a schematic diagram illustrating the general configuration of a prior art needle loom for forming a papermakers' felt.
FIG. 3 is an enlarged side view of a needle board with needles for the needle loom of FIG. 2 .
FIGS. 4A through 4C are a series of greatly enlarged side section views of a barbed needle of the needle loom of FIG. 2 as it (a) snags batt fiber from an overlying batt web (FIG. 4 A), (b) inserts the batt fiber into the base fabric (FIG. 4 B), and (c) retracts from the base fabric and batt web (FIG. 4 C).
FIG. 5 is a schematic diagram illustrating a needle loom for forming a papermakers' felt with the method of the present invention.
FIG. 6 is a series of greatly enlarged side views of a needle of the needle loom of FIG. 5 illustrating the cyclic oval path followed by the needle as it inserts batt fiber into the base fabric and retracts therefrom.
FIG. 7 is an enlarged view of a press felt with batt fibers that have been inserted at an oblique angle to the base fabric.
FIG. 8 is a partial cutaway perspective view of an alternative press felt having a duplex base fabric upon which the method of the present invention can be practiced.
FIG. 9 is a partial cutaway perspective view of an alternative press felt having a laminated base fabric upon which the method of the present invention can be practiced.
DETAILED DESCRIPTION OF THE INVENTION
The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown and described. 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. Like numbers refer to like components throughout. Components and layers may be exaggerated for clarity.
As used herein, the terms “machine direction” (MD) and “cross machine direction” (CMD) refer, respectively, to a direction aligned with the direction of travel of the papermakers' fabric on a papermaking machine, and a direction parallel to the fabric surface and transverse to the direction of travel. Also, both flat weaving and endless weaving methods are well known in the art for the production of a base fabric for a papermakers' felt, and the term “endless belt” as used herein refers to fabrics and press felts made by either method.
Referring now to the drawings, FIG. 1 illustrates an enlarged section of a press felt 10 ; the entirety of the press felt 10 , which is in an endless belt configuration, follows the pattern illustrated in FIG. 1 and need not be illustrated herein for those skilled in this art to understand its configuration.
As can be seen in FIG. 1, the illustrated press felt 10 includes a single layer plain weave base fabric 12 which comprises CMD yarns 14 and MD yarns 16 . Those skilled in this art will recognize that other fabric constructions can be employed as the base fabric 12 , including other single layer fabrics, duplex fabrics and triplex fabrics (these terms will be understood by those skilled in this art and need not be described in detail herein). Also, the base fabric 12 can comprise a so-called “laminated” or “stratified” structure that includes separate layers of fabrics. Virtually any weave pattern known to those skilled in this art, such as plain weaves, twills, satins, and the like, can be used for the base fabric 12 .
Two other exemplary base fabric constructions are illustrated in FIGS. 8 and 9. In FIG. 8, a press felt 60 includes a woven duplex base fabric 61 that comprises upper and lower sets of machine direction yarns 62 , 64 interwoven with cross machine direction yarns 66 . These are interwoven in a conventional 6 harness weave pattern in which each CMD yarn 66 passes over one upper MD 62 yarn and under one lower MD yarn 66 for each consecutive set of six upper and lower MD yarns 62 , 64 . The base fabric 61 is covered by a batt layer 68 . In FIG. 9, a press felt 70 includes a laminated duplex base fabric 71 that comprises an upper layer 72 formed of interwoven MD yarns 74 and CMD yarns 76 and a lower layer 78 formed of interwoven MD yarns 80 and CMD yarns 82 . Each of the upper and lower layers 72 , 78 follow a weave pattern in which the CMD yarns 76 , 82 pass over one of each six of their respective MD yarns 74 , 80 . The upper and lower layers 72 , 78 are secured with a batt layer 84 that covers the upper layer 72 . Other exemplary weave patterns for the layer(s) of the base fabric are illustrated and/or described in U.S. Pat. Nos. 4,503,113 to Smart; U.S. Pat. No. 4,565,737 to Murka, Jr. et al.; U.S. Pat. No. 4,896,702 to Crook; U.S. Pat. No. 4,976,293 to Aldrich; U.S. Pat. No. 5,110,672 to Zehle et al.; U.S. Pat. No. 5,135,802 to Gstrein et al.; and U.S. Pat. No. 5,549,967 to Gstrein et al., the disclosures of each of which are hereby incorporated herein by reference in their entireties. Other exemplary weave patterns are illustrated and described in S. Adanur, Paper Machine Clothing (Technomic Publishing Co., Inc. 1997).
The form of the yarns employed in the base fabrics 12 , 61 , 71 can vary, depending upon the desired properties of the final press felt. For example, the yarns may be multifilament yarns, monofilament yarns, twisted or cabled multifilament or monofilament yarns, spun yarns, or any combination thereof. Also, the materials from which the yarns employed in the fabric layers are formed may be those commonly used in press felts, such as polyamide, cotton, wool, polypropylene, polyester, aramid, or the like, and blends and combinations thereof. The diameters of the filaments of the yarns may vary from between about 0.02 mm to 0.6 mm (a range of 0.1 mm and 0.5 mm is preferred for CMD filaments and a range of 0.1 mm to 0.6 mm is preferred for MD filaments), and these filaments may be included either individually or in plies, which can then be used in twists or cables. The selected base fabric may vary from between about 8 to 150 machine direction yarns and 12 to 100 cross machine direction yarns per inch; the higher numbers of these ranges may include the yarns of multiple layers and laminates. The present invention can be particularly effective when used with fabrics having plied, cabled yarns having one or two plies of two or three twisted filaments, wherein the filaments have a diameter of between about 0.1 and 0.3 mm.
Referring again to FIG. 1, an upper batt layer 18 overlies the base fabric 12 , and a lower batt layer 20 underlies the base fabric layer 12 . These batt layers 18 , 20 are attached to the base fabric 12 through the needling process as described below. The batt layers 18 , 20 should be formed of material, such as a synthetic fiber like acrylic, aramid, polyester, or polyamide, or a natural fiber such as wool, that assists in wicking water away from the base fabric 12 . Preferred materials for the batt layers 18 , 20 include polyamide, aramid, wool, polyester and blends thereof. Fibers sized between 1.5 and 60 denier are preferred.
The weight and thickness of the batt layers 18 , 20 can vary, although it is preferable that the ratio of batt weight to total press felt weight is about between about 20 and 80 percent. Also, in some embodiments, it may be desirable to have additional batt layers (such as a batt layer between the layers of a stratified fabric) or to omit either of the batt layers 18 , 20 . Of course, the discussion of the batt layers 18 , 20 is equally applicable to the batt layers 68 , 84 of the press felts 60 , 70 .
Referring now to FIG. 2, a prior art needle loom, designated broadly at 40 , is schematically illustrated therein. The needle loom 40 includes four needling zones 42 a , 42 b , 42 c , 42 d , wherein batt material from a batt web, such as the batt layers 18 , 20 described hereinabove, is added to a base fabric, such as the base fabric 12 (the discussion is equally applicable to the base fabrics 61 , 71 and other base fabrics suitable for use in a press felt). The needling zones 42 a , 42 b , 42 c , 42 d are essentially identical with the exceptions of their locations on the needle loom 40 and their orientation relative to the loom 40 (i.e., the needling zone 42 d is oriented “upside down” relative to the other needling zones in order to needle the opposite side of the fabric); thus, the discussion hereinbelow directed to needling zone 42 a is equally applicable to the other needling zones 42 b , 42 c , 42 d.
FIG. 3 illustrates the needling zone 42 a , which includes a needle board 44 upon which a plurality of needles 46 are mounted. The needle board 44 is substantially flat and is mounted on a needle beam 43 that is in turn mounted to the frame of the loom 40 via a reciprocating needle motion unit 41 . A needle bed 50 is fixed beneath the needle board 44 and includes a plurality of apertures (not shown) that are sized and positioned to receive the needles 46 . The needle motion unit 41 moves the needle beam 43 and the needle board 44 in a reciprocating vertical motion relative to the needle bed 48 such that the needles 46 are able to enter and exit the apertures in the needle bed 50 .
As best seen in FIG. 4A, each needle 46 includes one or more barbs 47 that are configured such that a downwardly-moving needle 46 tends to snag and retain batt fiber within the barb 47 as the needle passes through a batt web 52 , but an upwardly-moving needle 46 tends to pass through the batt web 52 without snagging or retaining fiber. Typically, the needles 46 are between about 2.5 and 4.0 inches in length and 32 to 40 wire gauge in cross-section; most commonly, the needles 46 are triangular in cross-section, with equal sides. The barbs 47 typically have a throat length of about 0.5 to 0.8 mm and a throat depth of between about 0.06 and 0.15 mm. Most commonly, the barbs 47 are included on only one longitudinal edge of the needles 46 , although other configurations may also be employed. The needles 46 are typically included in a density of between about 1,000 and 4,000 needles per lineal meter, with densities of 1,340 and 2,680 needles per lineal meter being preferred.
FIGS. 4A through 4C illustrate the insertion of batt fiber into the base fabric 12 within the needling zone 42 a . As the needle 46 approaches the batt web 52 from above, the barbs 47 have no batt fiber retained therein. As the needle 46 continues moving downwardly such that its point penetrates and passes through the base fabric 12 (FIG. 4 B), the needle 46 snags batt fiber of the batt web 52 and forces it into and, in some instances, below the base fabric 12 . Once the batt fiber has been driven into the base fabric 12 , it tends to become entangled and ensnared therein. Thus, as the needle 46 retracts from the base fabric 12 (FIG. 4 C), the batt fibers tend to remain with the base fabric 12 and, eventually, form the batt layer 18 ; they tend not to be drawn from the base fabric 12 by the upward movement of the needle 46 because of the orientation of the barbs 47 and the absence of any “kick-up” associated with the barb 47 .
Of course, the movement of the needle 46 shown in FIGS. 4A through 4C is repeated numerous times as the base fabric 12 and the batt web 52 are conveyed through the needling zone 42 a . In the illustrated embodiment, the movement of the base fabric 12 and the batt web 52 is continuous. The base fabric 12 and batt web 52 can be needled in any or all of the needling zones 42 a , 42 b , 42 c , 42 d , any of which can have different needle configurations or stroke rates.
In many instances, the needling process is repeated multiple times; in some needling passes, the fibers from additional batt webs may be needled into the base fabric 12 , and in other passes there may be no additional batt fiber applied, as the needling pass is carried out to increase the entanglement and/or reduce the thickness of the batt layer 18 already formed on the fabric.
This process may have several shortcomings when needling is carried out with a continuously moving base fabric. As shown in FIG. 4B, if the barbs 47 of the needles 46 face rearwardly, the barbs 47 can contact the CMD yarns 14 and have a “sawing” effect on them as they enter and retract from the base fabric 12 , which of course can weaken the yarns for subsequent operation. As such, in many instances the needles 46 are mounted so that the barbs 47 do not face rearwardly (ie., not in the manner shown in FIG. 4) so that the sawing effect can be reduced.
Also, even in the absence of sawing by the barbs 47 , the interaction of the needle 46 with the base fabric 12 and batt web 52 can cause the base fabric 12 to stretch in a localized region just forward of the needle 46 and to compress just rearward of the needle 46 . This action can shift the positions of the yarns (particularly the CMD yarns 14 ), which can reduce the uniformity of the weave of the base fabric 12 . Also, shifting of the yarns can render subsequent needlings very unpredictable, as once the yarns have shifted position, there is no technique for realigning them prior to subsequent needling passes. As a result, any attempt to needle precisely based on the assumed positions of the yarns (such as to avoid having a needle “spear” a yam rather than pass between yarns) would likely be futile.
Moreover, the interaction of the needles 46 with the base fabric 12 and batt web 52 can also have the effect of causing the batt web 52 to “thin” forwardly of the needle 46 and “bunch up” rearwardly of the needle 46 . As a result, the uniformity of the surface of the batt layer 18 can be adversely impacted, particularly if this effect is magnified through multiple needling passes.
These problems can be addressed with the method of the present invention, which can be performed with a needle loom such as that schematically illustrated in FIG. 5 and designated broadly at 140 . As with the needle loom 40 of FIG. 2, the needle loom 140 includes four needling zones 142 a , 142 b , 142 c and 142 d , each of which includes a needle board 144 upon which needles 146 are mounted. Each needle board 144 is mounted on a needle beam 143 that is, in turn, mounted to the loom 140 .
In contrast to the loom 40 of FIG. 2, each needle beam 143 is mounted via a needle motion unit 141 such that, rather than undergoing reciprocating motion that is strictly vertical, the needle beam 143 follows a continuous predetermined path that defines an oval (see FIG. 6 ). As used herein, an “oval” path is intended to be a path that is continuous and largely curvilinear; it includes elliptical and non-elliptical paths as well as continuous reciprocating curvilinear paths that are asymmetric. Generally speaking, the oval path should include both upward and downward segments, each of which has both forward and rearward motion. The path should be selected such that, as the needles 146 enter the batt web 152 and continue into the base fabric 112 to insert batt fibers, the horizontal rate of travel of the needles 146 is substantially synchronized with the substantially constant horizontal rate of travel of the base fabric 112 and the batt web 152 (typically the base fabric 112 and the batt layer 152 travel at a rate of between about 0.05 and 0.75 inches per needle stroke, with a rate of 0.085 and 0.35 inches per needle stroke being preferred). Typically, the needles 146 are inserted into the fabric at similar stroke rates as is the case for the prior art loom 40 .
As an example, it may be desirable to convey a base fabric 112 and batt web 152 at a rate of 10 feet/minute. A similar horizontal speed would be desirable for the needles 146 during the insertion of the batt fiber into the base fabric 112 . If the needle stroke rate is 1,000 strokes/minute, and the vertical needle stroke length is 2.4 inches (which could, for example, correspond to a needle insertion depth of 0.5 inches into the needle bed), the resulting oval path would be approximately 2.4 inches by 0.12 inches. This ratio of long axis to short axis is typical; a range of between about 15 and 30 is preferred; as is a needle stroke length of between about 1.5 and 4 inches.
Those skilled in this art will recognize that there are multiple configurations for the needle motion unit 141 that can move the needle board 144 along an elliptical path. One example is that illustrated and described in U.S. Pat. No. 5,732,453 to Dilo et al. (Dilo), the disclosure of which is hereby incorporated herein by reference in its entirety. Dilo describes a needle loom that has sets of eccentrically-mounted connecting rods that are also connected to a needle bar. At least one connecting rod is mounted vertically and induces vertical motion in the needle bar, and at least one connecting rod is mounted horizontally and induces forward and rearward motion in the needle bar. The connecting rods are coupled to produce a desired path for the needles. Other needle loom configurations that may be suitable for the present invention include other eccentrically-mounted connecting rod configurations, slider-crank mechanisms four bar-linkages and their mechanical equivalents, intermittent magnetically-driven mechanisms, hydraulically- and pneumatically-driven systems, cam follower-type systems, and the like.
The needle loom 140 can be operated on the press felt of FIG. 1 and any of the press felts described hereinabove. The loom 140 is particularly suitable for press felts having fine yarns, as the discussion that follows demonstrates It is preferred that the finished press felt be subjected to repeated needling steps such that the batt layer is needled with between about 600 and 2,000 needle penetrations per square centimeter.
The oval path followed by the needles 146 can address the shortcomings noted above for prior art needle looms. First, the ability of the needles 146 to move horizontally with the base fabric 112 can reduce the tendency of the needles 146 to stretch the MD yarns of the base fabric 112 forward of the needle 146 and to compress the MD yarns to the rear of the needle 146 . As a result, the base fabric 112 can remain more uniform, which in turn can improve performance of the press felt. Also, the reduction of interaction between the needles 146 and the yarns of the base fabric 112 can enable fabrics with very fine yarns to be needled with less concern for yarn shifting or damage.
Second, a related advantage to the reduction or elimination of stretching/compressive force applied to the fabric is that the force experienced by the needle 146 is also reduced. As a result, finer needles and/or elevated needle density levels can be employed (for example, as many as 10,000 needles per lineal meter, using needles having a cross-section of 46 wire gauge). The use of higher densities and/or finer needles 146 can enable the press felt to be formed with fewer needling passes; also, the batt layer can be created with a smoother surface.
Third, the tendency of the batt web 152 to thin in front of and bunch to the rear of the inserted needles 146 is also reduced. As described above for the base fabric 112 , this effect can improve the consistency of the density and surface smoothness of the batt layer, which can positively impact the performance of the press felt.
Fourth, the “sawing” effect of the barbs of the needles 146 on the CMD yarns can be significantly reduced or eliminated, as the barbs are not forced against the CMD yarns by relative horizontal movement of the base fabric 112 . As such, the needles 146 may be oriented in the needle board 144 in a manner that is considered to be most desirable for the insertion of batt fibers without the fear of sawing CMD yarns. including facing rearwardly if such an orientation is desirable. In addition, needles with larger barb “kick-up” may also be employed if desirable. The reduction or elimination of “sawing” of the yarns enhances the opportunities for needling fabrics with fine yarns.
Fifth, the yarns of the base fabric 112 will tend to remain in their original positions during insertion of batt fiber rather than being displaced by the needles 146 . As a result, during subsequent needling passes with the base fabric 112 , the positions of those yarns should be more predictable. Accordingly, the positions of the yarns can be considered in planning the insertion of batt fiber in subsequent needling passes, such as to avoid the “spearing” of yarns described above. Again, this can be very advantageous when fabrics having very fine yarns are employed, as the spearing of a fine yam is likely to cause irreversible damage. One relatively direct method for determining the positions of the yarns is to include a marker, such as a CMD wire woven into the fabric or a visual marker imprinted on the fabric, that can be detected by a sensor associated with the loom. With the position of the marker known, the loom can then calculate or otherwise determine the positions of other yarns of the fabric, then perform the needling operation accordingly. Of course, other techniques for determining yam position, including automated scanning of the fabric, may also be used with the present invention.
Unlike the needling zones 42 a - 42 d of the needle loom 40 , the needling zones 142 a - 142 d are not identical, as needling zone 142 b includes a biplanar needling board 144 b and needling bed 150 b (FIGS. 5 and 7 ). The profiles of the lower surface of the needle board 144 b and the upper surface of the needle bed 150 b substantially match one another; each slopes downwardly at an angle of approximately 15 degrees to horizontal initially, then increases to an angle of 45 degrees to horizontal after a curved transition region, although these angles can be varied and still fall within the scope of the present invention. As they travel, the base fabric 112 and batt web 152 follow the profile of the needle bed 150 b , with the curved transition region 154 of the needle bed 152 providing a smooth transition surface for the base fabric 112 to change its travel direction. The general direction of needle insertion is vertical (like that for the needles 146 of needle zone 142 a ); i.e., the long axis of the oval of the needle path is substantially aligned with the longitudinal axis of each needle 146 . Thus, the disposition of the base fabric 112 and batt web 152 at an oblique angle to the long axis of the oval path causes the needles 146 to enter the base fabric 112 and the batt web 152 at an oblique angle.
The insertion of batt fibers at an oblique angle can be particularly advantageous for improving the anchoring of batt fibers within the base fabric 112 (as much as a 40 percent increase) due to the increased length of fiber in frictional contact with the yarns of the base fabric 112 and adjacent fibers. This can improve the abrasion resistance of the press felt and decrease the risk of fiber shedding without the use of fusable fibers or other adhesion-enhancing treatments. Moreover, the oblique entry angle of the batt fiber can also reduce the compressibility of the batt layer on the finished press felt.
The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although 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. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures.
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A method of forming a papermakers' felt first comprises providing a needle loom having a needle board, a plurality of needles mounted on the needle board, and a needle motion unit. The needle motion unit moves the needle board such that the needles mounted thereon travel on a predetermined path that includes upward and downward segments, wherein each of the upward and downward segments includes both forward and rearward motion. The method then comprises the step of continuously conveying a base fabric and a batt web overlying the base fabric in a first direction past the needle board. The base fabric includes a first set of machine direction yarns and a first set of cross machine direction yarns interwoven with the first set of machine direction yarns in a predetermine repeating pattern, and the batt web comprises batt fibers. The next step of the method is inserting batt fibers from the batt web into the base fabric with the plurality of needles as the base fabric is conveyed past the needle board and as the needle board travels along the predetermined path to form a batt layer attached to and overlying the base fabric. This method can reduce or eliminate negative effects on press felts resulting from needling.
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BACKGROUND OF THE DISCLOSURE
The present disclosure relates to warning lights, and more particularly to warning light assemblies for use with a motor vehicle.
Warning lights in the form of light bars mounted on emergency vehicles are well known in the art. Warning lights are utilized on many different types of vehicles to give visual indications of their presence during emergencies. Warning lights typically comprise an elongated base, a plurality of electronic components, and at least one lens portion. The elongated base may be provided in the form of an extrusion.
Warning lights are traditionally required by state and federal safety regulations to produce very bright light with specific color and emission patterns. As a result, the electronic components and warning light assemblies give off a great deal of heat. Warning light assemblies, particularly those using light emitting diodes (LEDs), are able to put out less light and can be damaged when operated at higher temperatures.
When used on emergency motor vehicles, warning lights are exposed to a wide range of environmental conditions. As dirt, water, and salt may corrode metal pars, fog the lenses, and destroy electronic components, warning lights must provide a weather-resistant barrier against the elements.
The modern trend is toward compact, low profile, self-contained warning light assemblies. Given the well-known issues of heat generation and protection from the elements, modern light bars must simultaneously provide a strong weather-resistant seal while providing an efficient pathway for heat generated within. U.S. Pat. Nos. 7,611,270 and 6,863,424, assigned to the assignee of the present disclosure are illustrative of warning light assemblies utilizing two different configurations to seal the warning light against the elements and provide an efficient path to direct heat away from the electronic components.
SUMMARY
According to aspects of the disclosure, a warning light for attachment to a vehicle comprises a thermally conductive longitudinally extending base, a plurality of mounting assemblies, a plurality of warning light assemblies, and at least one light-transmissive dome secured to the base.
The base has a pair of generally parallel longitudinal edges configured to engage the base and defines a pair of longitudinally extending light head shoe retention pockets adjacent to and oriented away from the edges. A pair of longitudinally extending ribs are spaced laterally inwardly of the retention pockets and project generally perpendicular from the base. The ribs terminate in a ridge and have a light head shoe retention lip projecting laterally toward the retention pocket at a point intermediate the base and the ridge. The light head shoe retention lip defines a retention channel oriented towards the base.
The plurality of mounting light assemblies generally comprise a plurality of brackets and a corresponding plurality of light head retention shoes. Each of the brackets are constructed of thermally conductive material, and have a generally planar bracket first portion in contact with the base and a generally planar bracket second portion to support a light generator. The bracket first portion is oriented generally perpendicular to the bracket second portion. A plurality of LEDs are mounted in thermally conductive contact to the bracket second portion.
Each of the plurality of light head retention shoes has a sole having a leading edge and toes configured to engage the retention pocket of the base and to maintain the bracket first portion in thermally conductive contact with the base. A rib engaging portion is located laterally opposite the foot. The rib engaging portion has a plurality of fingers configured to engage the distal ridge and a flexible retention member configured to reversibly engage the retention channel. A brace having a web and opposed sidewalls extends angularly between the rib engaging portion and the sole. The sidewalls project generally perpendicularly from the web and form a rigid structure.
In accordance with a further aspect of the disclosure, the light-transmissive dome has a generally planar main body portion oriented generally parallel to the base and longitudinally opposed inner and outer ends. Longitudinally extending sidewalls are contiguous with and extend generally perpendicularly from the main body portion, and terminate in a bottom edge. The main body portion defines a shallow longitudinally extending dome channel sized to receive a longitudinally extending panel. The outer end has an end wall contiguous with and extending generally perpendicularly from the main body portion, and terminates in a bottom edge. The end wall is oriented contiguous with and generally transverse to the sidewalls. The parallel longitudinal edges define a longitudinally extending dome-securing channel configured to receive the bottom edge of the longitudinally extending sidewalls and define an interior cavity.
In accordance with a further aspect of the disclosure, the longitudinally extending ribs define a center channel sized to receive at least one PC board and a plurality of arch-shaped bridges. Each of the bridges has laterally opposed pairs of feet. A snap fit connector extends away from the bridge. The snap fit connector is configured to reversibly mate with notch defined on at least one of the ribs.
The bridge also has a PC board retention member which comprises a cantilevered snap fit connector. A PC board retention snap works cooperatively with a nub. The nub is configured to engage one of a plurality of locator holes defined on longitudinally opposed ends of the control PC board to secure the control PC board within the center channel.
The configuration of the warning light in the current disclosure reduces the part count and the number of tools required for assembly. Additionally, the modular design of the disclosure gives greater flexibility in the lay out of the warning light. The light heads may be located anywhere along the base, since there are no restrictions or fixed points where the hardware must be located to secure the light heads to the base.
BRIEF DESCRIPTION OF THE DRAWINGS
Aspects of the preferred embodiment will be described in reference to the Drawings, where like numerals reflect like elements:
FIG. 1 is a side view of one embodiment of the warning light of the present disclosure, with particular emphasis on a light head shoe, a bracket, and the rib and retention pocket of the base, all other components of the warning light are omitted for clarity;
FIG. 2 is a perspective cross-sectional view of one embodiment of the warning light of the disclosure, the cross section is depicted as intersecting the warning light intermediate sidewalls of one of the light head shoes;
FIG. 3 is a perspective view of the embodiment of the light head retention shoe and the bracket of FIG. 2 ;
FIG. 4 shows a perspective view of one embodiment of the warning light; the generally concave light transmissive dome for a portion of the warning light is omitted for clarity, a mount to attach the warning light to a vehicle is also depicted;
FIG. 5 shows a rear view of the embodiment of the bracket depicted in FIG. 2 ;
FIG. 6 shows an embodiment of the bracket configured for use with shoes disposed at longitudinal ends of the base;
FIG. 7 is a perspective view of one embodiment of the base having a bridge received in a center channel defined intermediate the ribs, the warning light mount of FIG. 4 is also included;
FIG. 8 shows a perspective view of the underside of the light transmissive dome;
FIG. 9 shows a top plan view of the longitudinal ends of the base and the embodiment of the bracket depicted in FIG. 6 interfacing with a longitudinal end of the base, all other components of the warning light are omitted for clarity;
FIG. 10 is a perspective view of the bridge depicted in FIG. 7 , all other components of the warning light are omitted for clarity;
FIG. 11 shows a side view, partly in perspective, of one embodiment of an emergency warning light, the warning light mount depicted in FIG. 4 is also included;
FIG. 12 shows a cross-sectional view of the emergency warning light of FIG. 11 , the plurality of LED assemblies, mounting and control circuits have been omitted for clarity;
FIG. 13 is a cross-sectional view of one embodiment of the warning light with particular emphasis on the interface between one of the sidewalls and the longitudinal edge of the base, the plurality of LED assemblies, mounting and control circuits have been omitted for clarity; and
FIG. 14 is a cross-sectional view of one embodiment of the warning light with particular emphasis on the interface between the inner edge of the dome, the dome coupler and the wipe seal, the plurality of LED assemblies, mounting and control circuits have been omitted for clarity.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Embodiments of a warning light will now be described with reference to the Figures, wherein like numerals represent like parts throughout the FIGS. 1-8 . FIGS. 1 , 2 and 7 depict a warning light 100 for attachment to a vehicle comprises a longitudinally extending base 102 constructed from a thermally conductive material. In one embodiment, the base 102 is an aluminum extrusion.
The base 102 has a generally parallel pair of longitudinal edges 104 . Laterally inwardly of the longitudinal edges 104 , the base 102 defines a pair of light head retention pockets 106 . The pocket 106 is defined along substantially the entire length of the base 102 . The pockets 106 are defined on the base 102 such that the pocket opens generally away from the nearest longitudinal edge 104 toward the center of the base.
As seen in FIGS. 1 , 2 , 4 and 7 , a pair of ribs 108 extends substantially the entire length of the base 102 . The ribs 108 project from the base 102 intermediate the retention pockets 106 , and run longitudinally parallel with the retention pockets 106 and the edges 104 . The ribs 108 are equidistantly spaced from a central medial axis A-A ( FIG. 4 ) and prevent warping under the aerodynamic forces that may act on the base by providing structural support.
As best seen in FIGS. 1 , 2 and 7 , the ribs 108 project perpendicularly from the base 102 and terminate in a distal ridge 110 . In one embodiment, the ridge 110 is rounded and runs the length of the base 102 . A retention lip 112 projects laterally toward the retention pocket 106 . The retention lip 112 projects from the rib 108 at a point intermediate the base 102 and the ridge 110 .
The retention lip 112 has a ramped cross section having an increasing width, as best seen in the embodiment depicted in FIGS. 1 and 2 . The retention lip 112 defines a retention channel 114 oriented toward the base 102 and having a generally concave cross-section. The retention lip 112 projects along the entire length of the rib 108 .
As best seen in FIGS. 1 , 2 , 3 and 5 , the warning light also has a plurality of brackets 116 constructed from a thermally conductive material. Given its thermally conductive characteristics, superior workability and cost, in a preferred embodiment, the brackets 116 are constructed from sheets of aluminum. The brackets 116 have generally planar first and second portions 118 and 120 , respectively. The bracket 116 is configured such that the bracket second portion 120 is oriented generally perpendicular to the bracket first portion 118 .
As depicted in FIG. 2 , a plurality of light emitting diodes (LEDs) 121 are mounted in thermally conductive contact to the bracket second portion 120 . In the embodiment of the warning light 100 depicted in FIG. 2 , the LEDs 121 are mounted to a PC board 123 and are operatively mounted within a reflector 125 . Though a PC board 123 and reflector 125 are utilized in the embodiment shown, any of a multitude of configurations to mount the LEDs 121 to the bracket 116 may be utilized without departing from the scope of the disclosure.
In one embodiment depicted in FIGS. 1 , 2 and 5 , the bracket first portion 118 has a stepped configuration. In this embodiment, a ledge 122 extends perpendicularly between first and second generally planar steps 124 and 126 , respectively. The ledge 122 and first and second steps 124 and 126 define a plurality of engagement slots 128 .
In one embodiment best seen in FIG. 5 , the first step 124 has a plurality of laterally projecting retention pocket engaging extensions 130 . The pocket engaging extensions 130 are constructed to engage the retention pocket 106 on the base 102 to ensure the brackets are secured against the base 102 in thermally conductive contact with the base 102 .
A plurality of light head retention shoes 132 correspond in number with the brackets 116 , and are best shown in FIGS. 1-4 . The shoes 132 are configured to engage the brackets 116 to provide a secure connection between the brackets 116 and the base 102 . In one embodiment, the shoes 132 are molded plastic components.
Each shoe 132 has a sole 134 a leading edge 138 , and toes 140 configured to engage the bracket first portion 118 . The sole 134 is oriented generally parallel to the base 102 , and has a leading edge 138 . In one embodiment ( FIGS. 2 and 3 ), the sole 134 is generally planar. The planar configuration of the sole 134 is complementary to the bracket first portion 118 having a stepped configuration. The sole 134 is configured to maintain the first step 124 flat against the base 102 . A plurality of toes 140 project from the sole 134 along the leading edge 138 . The toes 140 are projections configured to engage the pocket 106 of the base 102 . The plurality of engagement slots 128 defined by the ledge and first and second steps are sized to receive the toes 140 adjacent the extensions 130 .
As seen in FIGS. 2 and 3 , when the embodiment of the light head shoe 132 is correctly installed, the leading edge 138 abuts the bracket ledge 122 . The toes 140 of the shoe 132 project through the slots and engage the retention pocket 106 , while the leading edge 138 simultaneously provides a retentive force on the bracket first portion in a direction laterally toward the edge 104 of the base 102 . In the embodiment of the bracket 116 having laterally projecting pocket engaging extensions, the retentive force provided by the leading edge 138 additionally causes the pocket engaging extensions 130 to engage the retention pocket 106 . The leading edge thus acts in concert with the pocket engaging extensions 130 to provide an additional retentive force on the bracket 116 directed towards the base 102 .
In an embodiment of the light head shoe 132 depicted in FIGS. 1-4 , the light head shoes 132 also have a rib engaging portion 142 . Specifically referring to FIGS. 1 and 2 , the rib engaging portion 142 is configured laterally opposite the leading edge 138 , and comprises a plurality of engagement fingers 144 and a flexible retention member 146 . The engagement fingers 144 are designed to engage the ridge 110 of the ribs 108 . The engagement fingers 144 are configured to complement the shape of ridge 110 . For example, in the embodiment where the ridge 110 is rounded, the fingers have an arch-shaped cross section.
In the embodiment shown in FIG. 3 , the flexible retention member 146 is disposed between the engagement fingers 144 . The flexible retention member 146 is a cantilevered snap fit connector. While the resilient retention member 146 comprises a u-shaped cantilevered snap fit connector in the embodiment depicted in FIGS. 2 and 3 , other shaped configurations of cantilevered snap fit connectors may be employed without departing form the scope of the disclosure.
Referring specifically to FIGS. 1 , 2 and 3 , a brace 148 extends angularly between the sole 134 and the rib engaging portion 142 . The brace 148 has a web 150 , and a pair of opposed sidewalls 152 projecting generally perpendicularly from the web 150 forming a rigid structure. In one embodiment, the sidewalls 152 are oriented parallel to one another, and extend angularly between the sole 134 and the rib engaging portion 142 . As shown in FIG. 1 , the engagement fingers 144 extend from the sidewalls 152 .
In addition to holding the brackets 116 against the base 102 , the shoes 132 also frictionally secure the brackets 116 longitudinally along the base 102 adjacent the edge 104 . To install the shoe 132 and bracket 116 , the bracket first portion 118 is first laid flat against the base 102 adjacent the edge 104 . The pocket engaging extensions 130 are installed in the pocket 106 and the toes 140 are inserted into the engagement slots 128 adjacent the pocket engaging extensions 130 . The toes 140 are inserted into the pocket 106 , and the leading edge 138 exerts a force on the bracket laterally toward the edge 104 . The shoe 132 is pivoted downwardly so that the engagement fingers 144 engage the ridge 110 , and the flexible retention member 146 snaps into the retention channel 114 .
A multitude of lighting configurations are possible as a result of the structural configuration of the base 102 , the brackets 116 and the shoes 132 . Since there are no fixed areas where hardware must be located to secure light heads to the base, different light patterns may be achieved using the same mounting apparatus and without perforating the base 102 for multiple mounting hardware configurations. Different LEDs and optical elements may also be used to change the pattern of the light emitted without changing the brackets 116 or the shoes 132 .
FIGS. 4 , 6 and 9 show one embodiment of the bracket 116 specifically configured for use with light head shoes 132 disposed at longitudinal ends 153 of the base 102 . In this embodiment, the bracket 116 includes a third bracket portion 154 . The third bracket portion 154 is configured adjacent to and extends angularly away from the second bracket portion 120 , and oriented generally transverse to the bracket first portion 118 .
As shown in FIGS. 4 , 7 and 10 , the warning light 100 includes an arch-shaped bridge 156 . The bridge 156 extends between laterally opposed pairs of feet 158 . As best seen in FIG. 7 , in this embodiment the ribs 108 define a center channel 160 laterally opposite the light head shoe retention lips 112 . The center channel 160 receives at least one PC board 162 configured to selectively energize the LEDs (not shown).
Referring specifically to FIG. 10 , the bridge 156 has at least one snap fit connector 164 that extends axially away from the feet 158 . The snap fit connector 164 includes a laterally projecting protrusion 166 at each lateral end. As seen in FIGS. 4 and 7 , the protrusion 166 reversibly mates with a longitudinal fixation notch 168 defined on the ribs 108 .
The bridge 156 has a PC board retention member 170 including a cantilevered snap 172 which cooperates with a nub 174 to secure the PC board 162 within the center channel 160 . A plurality of locator holes 176 are defined on longitudinally opposed ends of the PC board 162 and sized to receive the nub 174 . The cantilevered snap 172 has a barb 178 , which prevents the locator holes 176 from dislodging from the nub 174 to retain the PC board 162 in a fixed location relative to the base 102 .
In one embodiment depicted in FIG. 10 , the feet 158 have laterally extending tabs 180 extending inwardly and outwardly. In this embodiment, the base 102 defines a pair of tracks 181 defined intermediate and running longitudinally parallel with the ribs 108 ( FIG. 7 ). The tracks 181 are configured to receive the laterally extending tabs 180 and secure the bridge 156 to the base 102 .
Referring to FIGS. 8 , and 11 - 14 , a generally light transmissive dome 182 is operatively connectable to the base 102 to define an enclosure. In one embodiment, the dome 182 has a main body portion 184 oriented generally parallel to the base 102 . The main body portion 184 defines a longitudinally extending dome channel 186 which extends between longitudinally opposed outer and inner ends 188 and 190 , respectively ( FIG. 11 ) on top of the warning light. In one embodiment, the dome channel 186 spans a majority of the lateral width of the dome 182 .
A panel 187 is received in the dome channel 186 . In one embodiment, the panel 187 is opaque, and obscures views of the internal components of the warning light. The panel 187 may also act as a sunshade, to prevent radiant energy from the sun's rays from heating up the interior of the light bar. As disclosed, the panel 187 is secured to the dome 182 by a plurality of fasteners 189 extending through the dome to engage receptacles on the bridges 191 ( FIG. 10 ). The panel 187 is extruded aluminum, though a plurality of other suitable materials may be used.
As best seen in FIGS. 11-13 , sidewalls 192 extend the length of the dome 182 , between the outer and inner ends of the dome 188 and 190 . The sidewalls 192 are contiguous with and extend generally perpendicular from the main body 184 , and terminate in a bottom edge 194 . As shown in FIGS. 8 , 12 and 13 , a bottom wall portion 196 projects generally perpendicularly inwardly from the sidewall 192 . In this embodiment, the bottom edge 194 is defined at the laterally inward most portion of the bottom wall 196 .
In an embodiment of the dome 182 depicted in FIGS. 8 and 11 , an end wall 198 located at the first terminal end 188 projects generally perpendicularly away from the main body portion 184 . The end wall 198 terminates in a bottom edge 200 which includes fastener apertures 208 . The end wall 198 is oriented generally transverse to the sidewalls 192 , and the end wall 198 and end wall bottom edge 200 are contiguous with the sidewalls 192 and sidewall bottom edge 196 , respectively.
The dome 182 is configured to reversibly mate with the longitudinally extending base 102 . In one embodiment best seen in FIGS. 12 and 13 , the longitudinal edge 104 of the base 102 defines a longitudinally extending dome-securing channel 204 , which runs the length of the base 102 . The sidewall bottom edges 194 are configured such that the dome-securing channel 204 receives the sidewall bottom edges 194 , securing the dome 182 to the base 102 . To secure the dome 182 to the base 102 , the sidewall bottom edges 194 at the inner end 190 are first inserted into the dome-securing channel 204 . Once the sidewall bottom edges 194 are introduced into the dome-securing channel 204 , the dome 182 slides longitudinally on the base 102 until the end wall bottom edge 200 abuts one of the longitudinal ends 153 of the base 102 .
In one embodiment shown in FIG. 8 , the sidewall bottom edge 194 has an interrupted rail 202 , which projects away from the sidewall bottom edge 194 . The rail 202 is sized to fit in the dome-securing channel 204 and ensures a secure connection between the dome 182 and the base 102 along the edges 104 . The rail 202 is configured to reduce friction between the rail 202 and the dome-securing channel 204 during installation of the dome 182 .
As shown in FIG. 13 , a lip 206 which projects downwardly away from the sidewall bottom edge 194 adjacent the rail 202 may also be provided. The lip 206 further ensures that the elements do not penetrate the interior of the warning light 100 . The lip 206 extends along the front and rear edges of the light bar 100 to direct moisture away from the channel 204 .
As best seen in FIGS. 8 and 11 , a plurality of fasteners 205 are utilized to ensure a secure connection between the dome 182 and the base 102 . As best seen in FIG. 8 , the end wall bottom edge 200 defines a plurality of fastener holes 208 . The fastener holes 208 are defined on the end wall bottom edge 200 such that they align with fastener receptacles 210 defined on the base 102 ( FIG. 12 ).
As shown in FIGS. 4 , 7 and 10 , the bridges 156 are configured to cooperate with fasteners 189 to secure the dome 182 and the panel 187 to the base. As best seen in FIG. 10 , a plurality of fastener receptacles 191 project axially from the feet 158 of the arch shaped bridge 156 . The receptacles 191 are sized to receive the fasteners 189 and hold the main body portion 184 and the panel 187 against the base 102 . The receptacles 191 and fasteners 189 work in concert with the dome 182 , panel 187 , and base 102 to maintain the original shape of the warning light 100 , despite aerodynamic forces that act on warning lights when vehicles travel at high speeds.
As shown in FIGS. 11 and 14 , the warning light 100 has two generally light transmissive domes 182 . The domes 182 are installed on the base 102 such that the inner longitudinal ends 190 of the dome are oriented toward one another. The inner longitudinal ends 190 of the domes 182 are received in a dome coupler 212 when the longitudinal fasteners are secured to the dome securing pockets 210 .
The dome coupler 212 has the same sectional configuration as the inner ends 190 of the dome 182 . As seen in FIG. 14 , dome coupler 212 defines a general I-beam configuration when viewed in longitudinal section. The dome coupler 212 includes a wipe seal 214 which is configured to receive the inner ends 190 of the domes 182 . The wipe seal 214 ensures a secure, weather-resistant connection between the dome coupler 212 and the inner ends 190 of the domes 182 .
In this embodiment, the domes 182 and the dome coupler 212 are configured to provide a secure, weather-resistant connection with the base 102 , even if the length of the base 102 varies. The dome coupler 212 and wipe seal 214 ensure a weather-tight seal is created with the inner ends 190 of the domes 182 , even if the base 102 is longer than intended.
While a preferred embodiment has been set forth for purposes of illustration, the foregoing description should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations and alternatives may occur to one skilled in the art without departing from the spirit of the invention and scope of the claimed coverage.
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A warning light for attachment to a vehicle comprising a thermally conductive longitudinally extending base, a plurality of light head mount assemblies, a plurality of LED warning light assemblies, and a plurality of electronic control circuits. Said base has a pair of generally parallel longitudinal edges and a pair of ribs projecting perpendicularly from said base. Said light head mount assemblies comprise a bracket and a light head retention shoe. Said bracket has a generally planar bracket first portion and a generally planar bracket second portion oriented perpendicular to said first portion. Said light head shoe has a sole configured to engage said bracket first portion, a rib engaging portion, and a brace extending angularly therebetween. Said LED assemblies are mounted on said bracket second portion. Said dome has a main body portion, sidewalls configured to engage said edges, and end walls.
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FIELD OF THE INVENTION
This invention relates in general to radiation-sensitive compositions and in particular to radiation-sensitive compositions which contain a photocrosslinkable polymer. More specifically, this invention relates to novel radiation-sensitive compositions which are especially useful in the production of lithographic printing plates.
BACKGROUND OF THE INVENTION
The art of lithographic printing is based upon the immiscibility of oil and water, wherein the oily material or ink is preferentially retained by the image area and the water or fountain solution is preferentially retained by the non-image area. When a suitably prepared surface is moistened with water and an ink is then applied, the background or non-image area retains the water and repels the ink while the image area accepts the ink and repels the water. The ink on the image area is then transferred to the surface of a material upon which the image is to be reproduced, such as paper, cloth and the like. Commonly the ink is transferred to an intermediate material called the blanket, which in turn transfers the ink to the surface of the material upon which the image is to be reproduced.
Negative-working lithographic printing plates are prepared from negative-working radiation-sensitive compositions that are formed from polymers which crosslink in radiation-exposed areas. A developing solution is used to remove the unexposed portions of the coating to thereby form a negative image.
The most widely used type of negative-working lithographic printing plate comprises a layer of a radiation-sensitive composition applied to an aluminum substrate and commonly includes a subbing layer or interlayer to control the bonding of the radiation-sensitive layer to the substrate. The aluminum substrate is typically provided with an anodized coating formed by anodically oxidizing the aluminum in an aqueous electrolyte solution.
It is well known to prepare negative-working lithographic printing plates utilizing a radiation-sensitive composition which includes a photocrosslinkable polymer containing the photosensitive group: ##STR2## as an integral part of the polymer backbone. (See, for example, U.S. Pat. Nos. 3,030,208, 3,622,320, 3,702,765 and 3,929,489). A typical example of such a photocrosslinkable polymer is the polyester prepared from diethyl p-phenylenediacrylate and 1,4-bis(β-hydroxyethoxy)cyclohexane, which is comprised of recurring units of the formula: ##STR3## This polyester, referred to hereinafter as Polymer A, has been employed for many years in lithographic printing plates which have been extensively used on a commercial basis. These printing plates have typically employed an anodized aluminum substrate which has been formed by electrolytic anodization with an electrolyte comprised of phosphoric acid.
Polyesters in addition to Polymer A which are especially useful in the preparation of lithographic printing plates are those which incorporate ionic moieties derived from monomers such as dimethyl-3,3'-[(sodioimino)disulfonyl]dibenzoate and dimethyl-5-sodiosulfoisophthalate. Polyesters of this type are well known and are described, for example, in U.S. Pat. No. 3,929,489 issued Dec. 30, 1975. A preferred polyester of this type, referred to hereinafter as Polymer B, is poly[1,4-cyclohexylene-bis(oxyethylene)-p-phenylenediacrylate]-co-3,3'-[(sodioimino)disulfonyl]dibenzoate. Another preferred polyester of this type, referred to hereinafter as Polymer C, is poly[1,4-cyclohexylene-bis(oxyethylene)-p-phenylenediacrylate]-co-3,3'-[(sodioimino)disulfonyl]dibenzoate-co-3-hydroxyisophthalate.
While lithographic printing plates prepared from photocrosslinkable polymers such as Polymer A, Polymer B or Polymer C have many advantageous properties, they suffer from certain deficiencies which have limited their commercial acceptance. Thus, for example, shelf-life can be inadequate in that significant scumming in the background areas tends to manifest itself upon aging of the plate without special treatments of the support. As described in Cunningham et al, U.S. Pat. No. 3,860,426, shelf-life is enhanced by overcoating the phosphoric-acid-anodized aluminum substrate with a subbing layer containing a salt of a heavy metal, such as zinc acetate, dispersed in a hydrophilic cellulosic material such as carboxymethylcellulose. As described in European Patent Application No. 0218160, published Apr. 15, 1987, shelf-life can also be enhanced by applying a silicate layer over the anodic layer and then subjecting the silicate layer to a passivating treatment with a salt of a heavy metal, such as zinc acetate.
Omitting the use of such overcoating or passivating treatment of the substrate results in an increasing amount of coating residue on the plate following development as the plate ages, i.e., shelf-life is inadequate. However, the presence of zinc or other heavy metals in the printing plate in extractable form is undesirable because of the potential of contaminating the developer to the point that it can no longer be legally discharged into municipal sewage systems. Moreover, even with zinc acetate passivation or the addition of zinc acetate to a cellulosic subbing layer, the presensitized printing plates exhibit a substantial increase in toe speed on aging which results in undesirably low contrast.
A further disadvantage of the aforesaid photopolymer coatings is that the quantity of coating which can be processed with a given quantity of aqueous developer is less than desirable due to the fact that the coating breaks-up as fairly large particles which tend to redeposit on the imaged areas of the printing plate. The photopolymer coatings can be caused to break-up into finer particles upon development by drying them at higher temperatures than normally used. The use of higher drying temperatures, however, increases manufacturing costs and decreases production efficiency. Furthermore, although the particle sizes are finer, the quantity of photopolymer coating which can be processed before redeposit begins to occur is still less than desirable.
Other disadvantages associated with the use of the aforesaid photopolymers in lithographic printing plates include a tendency for undesirable mottle formation to occur and the need to use an undesirably high concentration of organic solvent in an aqueous-based developing composition. Mottle is particularly affected by the mechanics of film drying, determined by such factors as solvent evaporation rates.
Blinding problems are commonly encountered with commercially available aqueous-developable lithographic printing plates, so that there is an acute need in the art for an additive that is capable of improving ink receptivity.
It is known to incorporate non-light-sensitive, film-forming, resins in radiation-sensitive compositions of the type described hereinabove. For example, U.S. Pat. No. 3,929,489 refers to the use of phenolic resins, epoxy resins, hydrogenated rosin, poly(vinyl acetals), acrylic polymers, poly(alkylene oxides), and poly(vinyl alcohol) and U.S. Pat. No. 4,425,424 specifically discloses the use of polystyrene resin. These resins are employed for such purposes as controlling wear resistance of the coating, improving resistance to etchants and increasing the thickness of the radiation-sensitive layer so as to ensure complete coverage of the relatively rough metal substrate and thereby prevent blinding. However, these resins do not impart beneficial properties with respect to shelf-life or processing characteristics.
It is toward the objective of providing an improved radiation-sensitive composition, useful in the production of lithographic printing plates, that overcomes one or more of the disadvantages described above that the present invention is directed.
SUMMARY OF THE INVENTION
In accordance with this invention, a poly(N-acyl-alkyleneimine) is incorporated in a radiation-sensitive composition which includes a photocrosslinkable polymer containing the photosensitive group. ##STR4## as an integral part of the polymer backbone. The poly(N-acyl-alkyleneimine) improves the properties of the radiation-sensitive composition in regard to such factors as shelf-life, image contrast, developability and reduction of mottle and thereby provides a superior negative-working lithographic printing plate.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following copending commonly assigned U.S. patent applications are directed to inventions which are closely related to that described herein:
(1) U.S. patent application Ser. No. 554,232, filed July 17, 1990, pending "Radiation-Sensitive Composition Containing a Vinyl Pyrrolidone Polymer and Use Thereof in Lithographic Printing Plates" by Paul R. West et al.
(2) U.S. patent application Ser. No. 554,231, filed July 17, 1990, pending "Radiation-Sensitive Composition Containing An Unsaturated Polyester and Use Thereof in Lithographic Printing Plates" by Paul R. West et al.
(3) U.S. patent application Ser. No. 554,230, filed July 17, 1990, pending "Radiation-Sensitive Composition Containing Both a Vinyl Pyrrolidone Polymer and An Unsaturated Polyester and Use Thereof in Lithographic Printing Plates" by Paul R. West et al.
and (4) U.S. patent application Ser. No. 554,229, filed July 17, 1990, pending "Radiation-Sensitive Composition Containing Both a Poly(N-Acyl-Alkyleneimine) and An Unsaturated Polyester and Use Thereof in Lithographic Printing Plates" by Paul R. West et al.
As indicated hereinabove, the radiation-sensitive compositions of this invention contain a poly(N-acyl-alkyleneimine).
The poly(N-acyl-alkyleneimines) are well known polymers, some of which are commercially available, and are described in, for example, U.S. Pat. Nos. 3,470,267, 3,484,141, 3,640,909 and 4,474,928. They range in molecular weight from several thousand to several hundred thousand.
The poly(N-acyl-alkyleneimines) utilized in this invention include polymers comprised of repeating units of the formula: ##STR5## wherein R is a monovalent hydrocarbyl radical containing up to 20 carbon atoms and n is an integer with a value of 2 to 4. The hydrocarbyl radical represented by R can be unsubstituted or substituted with substituents such as halo, haloalkyl, hydroxyalkyl, and the like.
The poly(N-acyl-alkyleneimines) can be prepared by the ring-opening polymerization of heterocyclic monomers of the formula ##STR6## wherein R and n are as defined above. For example, N-acylated polyethyleneimines of the structure ##STR7## are advantageously prepared from oxazolines of the formula: ##STR8##
As indicated above, R can be any monovalent hydrocarbyl radical, substituted or unsubstituted, containing up to 20 carbon atoms including alkyl such as ethyl, halogenated alkyl such as dichloroethyl, aryl such as phenyl, halogenated aryl such as p-bromophenyl, aralkyl such as benzyl, cycloalkyl such as cyclohexyl and alkaryl such as tolyl.
Examples of the many different poly(N-acyl-alkyleneimines) include
poly(N-acetyl ethyleneimine)
poly(N-propionyl ethyleneimine)
poly(N-butyryl ethyleneimine)
poly(N-acetyl trimethyleneimine)
poly(N-propionyl trimethyleneimine)
poly(N-butyryl trimethyleneimine)
poly(N-hexanoyl trimethyleneimine)
poly(N-undecanoyl trimethyleneimine)
and the like.
The preferred poly(N-acyl-alkyleneimine) for use in this invention is poly(N-propionyl ethyleneimine). An alternative name for this polymer is poly(2-ethyl-2-oxazoline). It is available from the Dow Chemical Company under the trademark PEOX Polymer, with polymers of different molecular weight available as PEOX 50, PEOX 250 and PEOX 500.
The poly(N-acyl-alkyleneimine) is typically incorporated in the radiation-sensitive composition in an amount of from about 2 to about 30 percent by weight based on total polymer content, and more particularly in an amount of from about 5 to about 15 percent by weight.
The radiation-sensitive compositions of this invention comprise photocrosslinkable polymers, such as polyesters, containing the photosensitive group ##STR9## as an integral part of the polymer backbone. For example, preferred photocrosslinkable polymers are polyesters prepared from one or more compounds represented by the following formulae: ##STR10## where R 2 is one or more alkyl of 1 to 6 carbon atoms, aryl of 6 to 12 carbon atoms, aralkyl of 7 to 20 carbon atoms, alkoxy of 1 to 6 carbon atoms, nitro, amino, acrylic, carboxyl, hydrogen or halo and is chosen to provide at least one condensation site; and R 3 is hydroxy, alkoxy of 1 to 6 carbon atoms, halo or oxy if the compound is an acid anhydride. A preferred compound is p-phenylene diacrylic acid or a functional equivalent thereof. These and other useful compounds are described in U.S. Pat. No. 3,030,208 (issued Apr. 17, 1962 to Schellenberg et al); U.S. Pat. No. 3,702,765 (issued Nov. 14, 1972 to Laakso); and U.S. Pat. No. 3,622,320 (issued Nov. 23, 1971 to Allen), the disclosures of which are incorporated herein by reference. ##STR11## R 3 is as defined above, and R 4 is alkylidene of 1 to 4 carbon atoms, aralkylidene of 7 to 16 carbon atoms, or a 5- to 6-membered heterocyclic ring. Particularly useful compounds of formula (B) are cinnamylidenemalonic acid, 2-butenylidenemalonic acid, 3-pentenylidenemalonic acid, o-nitrocinnamylidene malonic acid, naphthylallylidenemalonic acid, 2-furfurylideneethylidenemalonic acid and functional equivalents thereof. These and other useful compounds are described in U.S. Pat. No. 3,674,745 (issued July 4, 1972 to Philipot et al), the disclosure of which is incorporated herein by reference. ##STR12## R 3 is as defined above; and R 5 is hydrogen or methyl. Particularly useful compounds of formula (C) are trans, trans-muconic acid, cis-transmuconic acid, cis, cis-muconic acid, α,α'-cis, trans-dimethylmuconic acid, α,α'-cis, cis-dimethylmuconic acid and functional equivalents thereof. These and other useful compounds are described in U.S. Pat. No. 3,615,434 (issued Oct. 26, 1971 to McConkey), the disclosure of which is incorporated herein by reference. ##STR13## R 3 is as defined above; and Z represents the atoms necessary to form an unsaturated bridged or unbridged carbocyclic nucleus of 6 to 7 carbon atoms. Such nucleus can be substituted or unsubstituted. Particularly useful compounds of formula (D) are 4-cyclohexene-1,2-dicarboxylic acid, 5-norbornene-2,3-dicarboxylic acid, hexachloro-5[2:2:1]-bicycloheptene-2,3-dicarboxylic acid and functional equivalents thereof. These and other useful compounds are described in Canadian Patent No. 824,096 (issued Sept. 30, 1969 to Mench et al), the disclosure of which is incorporated herein by reference. ##STR14## R 3 is as defined above; and R 6 is hydrogen, alkyl 1 to 12 carbon atoms, cycloalkyl of 5 to 12 carbon atoms or aryl of 6 to 12 carbon atoms. R 6 can be substituted where possible, with such substituents as do not interfere with the condensation reaction, such as halo, nitro, aryl, alkoxy, aryloxy, etc. The carbonyl groups are attached to the cyclohexadiene nucleus meta or para to each other, and preferably para. Particularly useful compounds of formula (E) are 1,3-cyclohexadiene-1,4-dicarboxylic acid, 1,3-cyclohexadiene-1,3-dicarboxylic acid, 1,5-cyclohexadiene-1,4-dicarboxylic acid and functional equivalents thereof. These and other useful compounds are described in Belgian Patent No. 754,892 (issued Oct. 15, 1970), the disclosure of which is incorporated herein by reference.
Preferred photocrosslinkable polyesters for use in this invention are p-phenylene diacrylate polyesters.
Printing plates of this invention comprise a support having coated thereon a layer containing the radiation-sensitive composition described above. Such plates can be prepared by forming coatings with the coating composition and removing the solvent by drying at ambient or elevated temperatures. Any one of a variety of conventional coating techniques can be employed, such as extrusion coating, doctor-blade coating, spray coating, dip coating, whirl coating, spin coating, roller coating, etc.
Coating compositions containing the mixture of polymers of this invention can be prepared by dispersing or dissolving the polymers in any suitable solvent or combination of solvents used in the art to prepare polymer dopes. The solvents are chosen to be substantially unreactive toward the polymers within the time period contemplated for maintaining the solvent and polymer in association and are chosen to be compatible with the substrate employed for coating. While the best choice of solvent will vary with the exact application under consideration, exemplary preferred solvents include alcohols, such as butanol and benzyl alcohol; ketones, such as acetone, 2-butanone and cyclohexanone; ethers, such as tetrahydrofuran and dioxane; 2-methoxyethyl acetate; N,N'-dimethylformamide; chlorinated hydrocarbons such as chloroform, trichloroethane, 1,2-dichloroethane, 1,1-dichloroethane, 1,1,2-trichloroethane, dichloromethane, tetrachloroethane, chlorobenzene; and mixtures thereof.
Suitable supports can be chosen from among a variety of materials which do not directly chemically react with the coating composition. Such supports include fiber based materials such as paper, polyethylene-coated paper, polypropylene-coated paper, parchment, cloth, etc.; sheets and foils of such materials as aluminum, copper, magnesium zinc, etc.; glass and glass coated with such metals as chromium alloys, steel, silver, gold, platinum, etc.; synthetic resin and polymeric materials such as poly(alkyl acrylates), e.g., poly(methyl methacrylate), polyester film base, e.g., poly(ethylene terephthalate), poly(vinyl acetals), polyamides, e.g., nylon and cellulose ester film base, e.g., cellulose nitrate, cellulose acetate, cellulose acetate propionate, cellulose acetate butyrate and the like.
Preferred support materials include zinc, anodized aluminum, grained aluminum, and aluminum which has been grained and anodized. Particularly preferred support materials are described in Miller et al, U.S. Pat. No. 4,647,346, issued Mar. 3, 1987, and Huddleston et al, U.S. Pat. No. 4,865,951, issued Sept. 12, 1989.
The support can be preliminarily coated-- i.e., before receipt of the radiation-sensitive coating--with known subbing layers such as copolymers of vinylidene chloride and acrylic monomers--e.g., acrylonitrile, methyl acrylate, etc. and unsaturated dicarboxylic acids such as itaconic acid, etc.; carboxymethyl cellulose, gelatin; polyacrylamide; and similar polymer materials. A preferred subbing composition comprises benzoic acid and is described in Miller et al, U.S. Pat. No. 4,640,886, issued Feb. 3, 1987.
The optimum coating thickness of the radiation-sensitive layer will depend upon such factors as the particular application to which the printing plate will be put, and the nature of other components which may be present in the coating. Typical coating thicknesses can be from about 0.05 to about 10.0 microns or greater, with thicknesses of from 0.1 to 2.5 microns being preferred.
The printing plate of this invention can be exposed by conventional methods, for example, through a transparency or a stencil, to an imagewise pattern of actinic radiation, preferably rich in ultraviolet light, which crosslinks and insolubilizes the radiation-sensitive polymer in the exposed areas. Suitable light sources include carbon arc lamps, mercury vapor lamps, fluorescent lamps, tungsten filament lamps, "photoflood" lamps, lasers and the like. The exposure can be by contact printing techniques, by lens projection, by reflex, by bireflex, from an image-bearing original or by any other known technique.
The exposed printing plate of this invention can be developed by flushing, soaking, swabbing or otherwise treating the radiation-sensitive composition with a solution (hereinafter referred to as a developer) which selectively solubilizes (i.e., removes) the unexposed areas of the radiation-sensitive layer. The developer is preferably an aqueous solution having a pH as near to neutral as is feasible.
In a preferred form, the developer includes a combination of water and an alcohol that is miscible with water, or able to be rendered miscible by the use of cosolvents or surfactants, as a solvent system. The proportions of water and alcohol can be varied widely but are typically within the range of from 40 to 99 percent by volume water and from 1 to 60 percent by volume alcohol. Most preferably, the water content is maintained within the range of from 60 to 90 percent by volume. Any alcohol or combination of alcohols that does not chemically adversely attack the cross-linked radiation-sensitive layer during development and that is miscible with water in the proportions chosen for use can be employed. Exemplary of useful alcohols are glycerol, benzyl alcohol, 2-phenoxyethanol, 1,2-propanediol, sec-butyl alcohol and ethers derived from alkylene glycols--i.e., dihydroxy poly(alkylene oxides)--e.g., dihydroxy poly(ethylene oxide), dihydroxy poly(propylene oxide), etc.
It is recognized that the developer can, optionally, contain additional addenda. For example, the developer can contain dyes and/or pigments. It can be advantageous to incorporate into the developer anti-scumming and/or anti-blinding agents as is well recognized in the art.
A preferred developing composition for use with the novel lithographic printing plates of this invention is an aqueous composition including:
(a) a nontoxic developing vehicle, such as butyrolactone, phenoxy propanol, phenoxy ethanol, benzyl alcohol or methyl pyrrolidone, which is a non-solvent for any of the components of the lithographic plate;
(b) a first surfactant comprising a sodium, lithium or potassium salt of xylene sulfonic acid;
(c) a second surfactant comprising a sodium, lithium or potassium salt of toluene, ethyl benzene, cumene or mesitylene sulfonic acid;
(d) a third surfactant comprising a sodium, lithium or potassium salt of an alkyl benzene sulfonic acid, the alkyl group containing at least ten carbon atoms, or an alkyl naphthalene sulfonic acid, the alkyl group containing from one to four carbon atoms;
(e) a cold water soluble film-forming agent such as polyvinyl pyrrolidone, polystyrene/maleic anhydride copolymers, polyvinyl alcohol, polyvinyl methyl ethers and polystyrene/vinyl acetate copolymers;
(f) an alkanolamine desensitizing agent such as diethanolamine;
and (g) an acid, such as citric, ascorbic, tartaric, glutaric, acetic, phosphoric, sulfuric or hydrochloric acid, to control the pH of the developing composition.
These developing compositions are described in copending commonly assigned U.S. patent application Ser. No. 379,823, filed July 14, 1989, "Aqueous Developer Composition For Developing Negative-Working Lithographic Printing Plates", by J. E. Walls, the disclosure of which is incorporated herein by reference. A developing composition of this type is commercially available from Eastman Kodak Company, Rochester, N.Y., as KODAK AQUEOUS PLATE DEVELOPER MX-1469-1.
After development, the printing plate can be treated in any known manner consistent with its intended use. For example, lithographic printing plates are typically subjected to desensitizing etches.
In addition to the photocrosslinkable polymer and the poly(N-acyl-alkyleneimine), a number of other addenda can be present in the coating composition and ultimately form a part of the completed printing plate. For example, radiation sensitivity of the radiation-sensitive polymeric composition can be enhanced by incorporating therein one or more spectral sensitizers. Suitable spectral sensitizers include anthrones, nitro sensitizers, triphenylmethanes, quinones, cyanine dyes, naphthones, pyrylium and thiapyrylium salts, furanones, anthraquinones, 3-ketocoumarins, thiazoles, thiazolines, naphthothiazolines, quinalizones, and others described in U.S. Pat. No. 4,139,390 and references noted therein. Preferred sensitizers include the 3-ketocoumarins described in U.S. Pat. No. 4,147,552 and the thiazoline sensitizers of U.S. Pat. No. 4,062,686. Such sensitizers can be present in the compositions in effective sensitizing amounts easily determined by one of the ordinary skill in the art.
The coating composition can contain pigments preferably having a maximum average particle size less than about 3 micrometers. These pigments can provide a visible coloration to an image before or after development of the element. Useful pigments are well known in the art and include titanium dioxide, zinc oxide, copper phthalocyanines, halogenated copper phthalocyanines, quinacridine, and colorants such as those sold commercially under such trade names as Monastral Blue and Monastral Red B. The pigments are generally present in the compositions in an amount within the range of from 0 to about 50 percent (by weight) based on the total dry composition weight. Preferred amounts are within the range of from about 5 to about 20 percent (by weight).
It is frequently desirable to add print out or indicator dyes to the compositions to provide a colored print out image after exposure. Useful dyes for such purpose include monoazo, diazo, methine, anthraquinone, triarylmethane, thiazine, xanthene, phthalocyanine, azine, cyanine and leuco dyes as described, for example, in U.S. Pat. Nos. 3,929,489 and 4,139,390 and references noted therein. Such dyes are present in amounts readily determined by a person of ordinary skill in the art.
It is recognized that the radiation-sensitive composition of this invention can become crosslinked prior to intended exposure if the compositions or printing plates of this invention are stored at elevated temperatures, in areas permitting exposure to some quantity of actinic radiation and/or for extended periods of time. To insure against crosslinking the composition inadvertently before intended exposure to actinic radiation, stabilizers can be incorporated into the radiation-sensitive compositions and printing plates of this invention. Useful stabilizers include picoline N-oxide; phenols, such as 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butylanisole and p-methoxyphenol; hydroquinones such as hydroquinone, phloroglucinol and 2,5-di-tert-butylhydroquinone; triphenylmetallics, such as triphenylarsine; triphenylstilbene; and tertiary amines, such as N-methyldiphenylamine.
Still other addenda useful in the printing plates of this invention include antioxidants, surfactants, anti-scumming agents, and others known in the art.
Binders or extenders can optionally be incorporated into the radiation-sensitive composition. Such binders or extenders can be present in an amount within the range of from 0 to about 50 percent (by weight) based on total dry composition weight. Suitable binders include styrene-butadiene copolymers; silicone resins; styrene-alkyd resins; silicone-alkyd resins; soya-alkyd resins; poly(vinyl chloride); poly(vinylidene chloride); vinylidene chlorideacrylonitrile copolymers; poly(vinyl acetate); vinyl acetate-vinyl chloride copolymers; poly(vinyl acetals), such as poly(vinyl butyral); polyacrylic and -methacrylic esters, such as poly(methyl methacrylate), poly(n-butyl methacrylate) and poly(isobutyl methacrylate); polystyrene; nitrated polystyrene; polymethylstyrene; isobutylene polymers; polyesters, such as poly(ethylene-coalkaryloxy-alkylene terephthalate); phenolformaldehyde resins; ketone resins; polyamides; polycarbonates; polythiocarbonates, poly(ethylene 4,4'-isopropylidenediphenylene terephthalate); copolymers of vinyl acetate such as poly(vinyl-m-bromobenzoate-co-vinyl acetate); ethyl cellulose, poly(vinyl alcohol), cellulose acetate, cellulose nitrate, chlorinated rubber and gelatin. Methods of making binders or extenders of this type are well known in the prior art. A typical resin of the type contemplated for use is Piccolastic A50™, commercially available from Hercules, Inc., Wilmington, Del. Other types of binders which can be used include such materials as paraffin and mineral waxes.
The invention is further illustrated by the following examples of its practice.
EXAMPLE 1
Coating compositions useful in preparing lithographic printing plates were prepared in accordance with the following formulations:
______________________________________ Amounts (grams) Composi- Composi-Component tion 1 tion 2______________________________________(1) Polymer A (15% by weight solu- 144.16tion in 1,2-dichloroethane)(2) Polymer B (15% by weight solu- 144.15tion in 1,2-dichloroethane)(3) MONASTRAL Red pigment (7% by 52.13 51.54weight dispersion in 1,2-chloroethane)(4) 2-[Bis(2-furoyl)methylene-1- 0.63methyl-naptho[1,2-d]thiazoline(5) 3,3'-Carbonylbis(5,7-di-n- 1.03propoxycoumarin)(6) 2,6-Di-t-butyl-p-cresol 0.60 0.68(7) N-(4-Chlorobenzenesulfonyloxy)- 1.77 1.141,8-naphthalimide(8) Dihydroanhydropiperidinohexose 0.08 0.02reductone(9) Leuco propyl violet 0.46 0.28(10) MODAFLOW coating aid* 0.02(11) FC-430 surfactant** 0.15(12) 1,2-Dichloroethane 597.06 597.06______________________________________ *MODAFLOW coating aid is a copolymer of ethyl acrylate and 2ethylhexyl acrylate manufactured by Monsanto Corporation. **FC430 surfactant is a mixture of fluoroaliphatic polymeric esters manufactured by Minnesota Mining and Manufacturing Company.
In the above formulations, (1) and (2) serve as film-forming polymers, (3) serves as a colorant, (4) and (5) serve as spectral sensitizers, (6) serves as a stabilizer, (7) serves as a photooxidant, (8) serves as an antioxidant, (9) serves as a print-out dye, (10) and (11) serve as coating aids and (12) serves as a solvent.
A control coating was prepared by incorporating polystyrene resin (available under the trademark Piccolastic A-50 from Hercules, Inc.) in Composition 1 in an amount of 15.3% of the total polymer content. Compositions within the scope of the present invention were prepared by incorporating PEOX 50 polymer in Compositions 1 and 2 in an amount of 15.3% of the total polymer content.
Each composition was used to prepare a lithographic printing plate by coating it over a phosphoric-acid-anodized aluminum substrate provided with a thin carboxymethyl cellulose subcoat. Each coating was baked for 2 minutes at 100° C. as an accelerated aging test. The coatings that contained the PEOX 50 polymer resin could be imaged and developed cleanly after the bake treatment, while the comparison coating that contained the polystyrene resin left a heavy coating residue on the substrate under the same conditions. These results demonstrate the ability of a poly(N-acyl-alkyleneimine) to improve the shelf-life of the radiation-sensitive photopolymer coatings without having to resort to the use of treatments with heavy metal salts such as zinc acetate. Similar improved results are also obtained with a radiation-sensitive composition containing Polymer C.
EXAMPLE 2
A lithographic printing plate similar to that described in Example 1 was prepared using Composition 2. A second plate was prepared in which PEOX 250 polymer was incorporated in the radiation-sensitive layer in an amount of 10 percent by weight based on total polymer content. The plates were immersed in a developing solution consisting of 3 parts water and 1 part of a developer concentrate of the formula:
______________________________________Ingredient Percent______________________________________2-(2-ethoxyethoxy)ethanol 16.0benzyl alcohol 7.5diethanolamine 5.1poly (vinyl pyrrolidone) 1.0AEROSOL OT* 0.1water 70.3 100.0______________________________________ *Dioctyl ester of sodium sulfosuccinic acid manufactured by American Cyanamid Company.
After standing 90 seconds, the developing solutions were briefly agitated and then examined. The coating containing Polymer B remained intact, but slowly peeled away from the anodized aluminum substrate on standing in the diluted developing solution. The coating containing the mixture of Polymer B and 10% PEOX 250 polymer immediately disintegrated as fine particles on agitation of the dilute developing solution. This demonstrates the ability of a poly(N-acyl-alkyleneimine) to improve the aqueous processability of lithographic printing plates. Comparison of the plate prepared with Polymer B and the plate prepared with a mixture of Polymer B and 10% PEOX 250 polymer under machine processing conditions using one part of the above-described concentrate diluted with one part of water also demonstrated that break-through and clean-up were much more rapid with the plate containing the mixture of Polymer B and 10% PEOX 250 polymer.
EXAMPLE 3
Several thousand linear meters of anodized aluminum were flow coated with a radiation-sensitive composition containing Polymer B and 10% of PEOX 250 polymer. The resulting coatings were observed to be remarkably smooth and substantially free of any coating mottle. Coatings produced under identical conditions without the PEOX 250 polymer additive showed perceptible mottle.
EXAMPLE 4
Lithographic printing plates similar to that described in Example 1 were prepared from the following radiation-sensitive compositions:
(1) Polymer B plus 10% PVP [poly(N-vinyl-2-pyrrolidone)]
(2) Polymer B plus 15% PVP
(3) Polymer B plus 6% PEOX 250 polymer
(4) Polymer B plus 12% PEOX 250 polymer
The plates were immersed for 90 seconds in a developing solution and then rinsed with water. The developing solution was prepared by mixing one part of water with one part of a concentrate of the formula:
______________________________________Ingredient Percent______________________________________benzyl alcohol 4.50CARBOWAX 350* 6.00diethanolamine 5.00POLYWET Z-1766** 0.10poly(vinyl pyrrolidone) 1.00BELCLENE 200*** 0.05water 83.35 100.00______________________________________ *Polyethylene glycol, manufactured by Union Carbide Corporation. **Sodium salt of a polyfunctional acrylic oligomer, manufactured by Uniroyal Chemical. ***Polymaleic acid, manufactured by CibaGeigy Corporation.
The unexposed coatings containing 10% or 15% PVP remained intact, the coating containing 6% PEOX 250 polymer was partially removed, and the coating containing 12% PEOX 250 polymer was completely developed away. These results demonstrate that PEOX 250 polymer makes photopolymer compositions processable in developing solutions containing more than 90% water at polymer loadings below those at which PVP is effective. The exceptional processing benefits derived from the addition of PEOX 250 polymer are believed to be related to the fact that PEOX 250 polymer is compatible with Polymer B, i.e., no phase separation occurs.
EXAMPLE 5
Incubation tests were carried out to determine the effectiveness of N-acyl-alkyleneimine polymers in providing and maintaining high contrast. In carrying out these tests, printing plates were prepared by coating the photosensitive formulation described in Example 1 as Composition 1, containing additives as indicated below, onto phosphoric acid-anodized aluminum in an amount sufficient to provide a Polymer A coverage of 810 milligrams per square meter. The contrast of each coating was determined from its sensitometric response immediately after coating and again after incubation for two weeks at 50° C. All coatings were processed with Kodak Aqueous Plate Developer MX-1469-1, available from Eastman Kodak Company, Rochester, N.Y.
The results obtained are indicated in Table I below.
TABLE I______________________________________ Coating Wt. Fresh IncubatedTest Additive (mg/m.sup.2) Contrast Contrast______________________________________Control A none -- 1.20 0.83Control B polystyrene 146 0.88 0.68Example 1 PEOX 50 146 0.97 1.03______________________________________
Thus, the control examples exhibited a 20 to 30% drop in contrast on aging, whereas the coating with the PEOX 50 additive showed no loss in contrast under the same conditions.
The poly(N-acyl-alkyleneimines) are both solvent soluble and water soluble. These solubility characteristics render them especially advantageous for use in the present invention since they facilitate both coating from solvent solution to form the radiation-sensitive layer and subsequent development by the use of "aqueous" developing solutions, i.e., developing solutions which are predominantly water but do contain small amounts of organic solvent. Incorporation of a poly(N-acyl-alkyleneimine) in the radiation-sensitive composition permits the use of lower concentrations of organic solvent in the aqueous developing solution, as compared with an otherwise identical composition that does not contain the poly(N-acyl-alkyleneimine). Also, significantly less mottle results when the poly(N-acyl-alkyleneimine) is employed and higher contrast images are achieved.
Current trends in the lighographic printing plate industry favor the use of "aqueous developers." By this is meant that the developer used to process the printing plate, either by hand or by machine, contains little or no organic solvent and that any organic solvent which is present is nontoxic and a high boiling material with a very low vapor pressure. Other ingredients included in the developer, such as salts and surfactants, are nontoxic and biodegradable. The present invention is especially well adapted, by virtue of the polymeric materials incorporated in the radiation-sensitive composition, for use with such "aqueous developers."
The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
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Radiation-sensitive compositions which are especially useful in the production of negative-working lithographic printing plates comprise a photocrosslinkable polymer containing the photosensitive group ##STR1## as an integral part of the polymer backbone and, in an amount sufficient to improve the properties of the composition, a poly(N-acyl-alkleneimine). The poly(N-acyl-alkyleneimine) improves the properties of the radiation-sensitive composition in regard to such factors as shelf life, image contrast, developability and reduction in mottle and thereby provides a superior lithographic printing plate.
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This application is a continuation of application Ser. No. 09/941,425, filed Aug. 28, 2001, now U.S. Pat. No. 6,666,890; which is a continuation of application Ser. No. 09/553,000, filed Apr. 19, 2000, now U.S. Pat. No. 6,350,283; the disclosures of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to interbody spinal implants preferably adapted for placement in pairs side by side to either side of the midline with or without a space therebetween into a space created across the height of a disc space and between two adjacent vertebral bodies, after the removal of damaged spinal disc material, for the purpose of correcting spinal disease at that interspace. The spinal implants comprise of cortical bone either in a form such as a material that may naturally be available from a body; or as a composite material of cortical bone in particles or spindles, and the like in a resorbable plastic, ceramic, or other so long as it is structurally suitable for the intended purpose. The implants are adapted such that fusion occurs at least in part through the implants themselves.
2. Description of the Related Art
Surgical interbody spinal fusion generally refers to the methods for achieving a bridge of bone tissue in continuity between adjacent vertebral bodies and across the disc space to thereby substantially eliminate relative motion between the adjacent vertebral bodies. The term “disc space” refers to the space between adjacent vertebral bodies normally occupied by a spinal disc.
Spinal implants can have opposed upper and lower surfaces that are arcuate or non-arcuate transverse to the longitudinal axis of the implant along at least a portion of the length of the implant. Implants having arcuate opposed portions are adapted to be implanted across and beyond the height of the restored disc space, generally into a bore formed across the height of a disc space. Some of the advantages offered by implants with arcuate opposed portions include: 1) the installation of the implant into vascular bone made possible by the creation of a bore into the bone of the adjacent vertebral bodies; 2) the implant's geometric shape is easy to manufacturer 3) the implant can include external threads to facilitate insertion into the implantation space; and 4) the implant provides more surface area to contact the adjacent vertebral bodies, than would a flat surface. Some disadvantages associated with implants having arcuate opposed portions include: 1) the creation of a bore into the adjacent vertebral bodies to form the implantation space results in a loss of the best structural bone of the vertebral endplate; 2) the implant needs to have a larger cross section to fill the prepared implantation site which may be more difficult to install, especially from a posterior approach; and 3) the width of the implant is generally related to the height of the implant, so if the implant is for example a cylinder, then the width of the implant may be a limiting factor as to the height of the implant and therefore its possible usefulness.
Implants having non-arcuate upper and lower opposed portions may be impacted into a space resembling the restored disc space and need only be placed against a “decorticated endplate”. A decorticated endplate is prepared by a surgeon to provide access to the underlying vascular bone. Some of the advantages provided by implants having non-arcuate opposed portions include: 1) preserving the best bone in the endplate region; 2) the height of the implant is independent of its width; 3) the implant can be of a geometric shape and the opposed upper and lower surfaces can be flat; 4) the implant can be installed as modular unit; and 5) the implant can provide a broad surface contact. Some of the disadvantages provided by implants having non-arcuate opposed portions include: 1) the implants cannot be threaded in and must be impacted into the installation space; and 2) the recipient site may be more difficult to prepare.
Human vertebral bodies have a hard outer shell of compacted dense cancellous bone (sometimes referred to as the cortex) and a relatively softer, inner mass of cancellous bone. Just below the cortex adjacent the disc is a region of bone referred to herein as the “subchondral zone”. The outer shell of compact bone (the boney endplate) adjacent to the spinal disc and the underlying subchondral zone are together herein referred to as the boney “end plate region” and, for the purposes of this application, is hereby so defined. A circumferential ring of dense bone extends around the perimeter of the endplate region and is the mature boney successor of the “apophyseal growth ring”. This circumferential ring is formed of very dense bone and for the purposes of this application will be referred to as the “apophyseal rim”. For purposes of this application, the “apophyseal rim area” includes the apophyseal rim and additionally includes the dense bone immediately adjacent thereto. The spinal disc that normally resides between the adjacent vertebral bodies maintains the spacing between those vertebral bodies and, in a healthy spine, allows for the normal relative motion between the vertebral bodies.
FIG. 1 of the attached drawings shows a cross-sectional top plan view of a vertebral body V in the lumbar spine to illustrate the dense bone of the apophyseal rim AR present proximate the perimeter of the vertebral body V about the endplate region and an inner mass of cancellous bone CB. The structure of the vertebral body has been compared to a core of wet balsa wood encased in a laminate of white oak. The apophyseal rim AR is the best structural bone and is peripherally disposed in the endplate of the vertebral body.
FIG. 2 is a top plan view of a fourth level lumbar vertebral body V shown in relationship anteriorly with the aorta and vena cava (collectively referred to as the “great vessels” GV). FIG. 3 is a top plan view of a first sacral level vertebral body V shown in relationship anteriorly with the iliac arteries and veins referred to by the designation “IA-V”. Because of the location of these fragile blood vessels along the anterior aspect of the lumbar vertebrae, no hardware should protrude from between the vertebral bodies and into the great vessels GV and iliac arteries and veins IA-V.
Fusion implants preferably have a structure designed to promote fusion of the adjacent vertebral bodies by allowing for the growth of bone through the implant from vertebral body to adjacent vertebral body. This type of implant is intended to remain indefinitely within the patient's spine unless made of a resorbable or bioresorbable material such as bone that can be biologically replaced in the body over time such that it need not be removed as it is replaced over time will no longer be there. Implants may be sized to have a width generally as great as the nucleus portion of the disc or as wide as the area between the limit lines LL as shown in FIG. 4 . There are at least two circumstances where the use of such a wide implant is not desirable. Under these circumstances, the use of a pair of implants each having a width less than one half the width of the disc space to be fused is preferred. The first circumstance is where the implants are for insertion into the lumbar spine from a posterior approach. Because of the presence of the dural sac within the spinal canal, the insertion of a full width implant in a neurologically intact patient could not be performed from a posterior approach. The second circumstance is where the implants are for endoscopic, such as laproscopic, insertion regardless of the approach as it is highly desirable to minimize the ultimate size cross-sectionally of the path of insertion.
The ability to achieve spinal fusion is inter alia directly related to the vascular surface area of contact over which the fusion can occur, the quality and the quantity of the fusion mass, and the stability of the construct. The overall size of interbody spinal fusion implants is limited, however, by the shape of the implants relative to the natural anatomy of the human spine. For example, if such implants were to protrude from the spine they might cause injury to one or more of the proximate vital structures including the large blood vessels or neurological structures.
FIG. 4 shows a top plan view of the endplate region of a vertebral body V with the outline of a related art implant A and implant 100 of one embodiment of the present invention installed, one on each side of the centerline of the vertebral body V. The length and width of related art implant A is limited by its configuration and the vascular structures anteriorly (in this example) adjacent to the implantation space. The presence of limiting corners LC on the implant precludes the surgeon from utilizing an implant of this configuration having both the optimal width and length because the implant would markedly protrude from the spine.
Related art implants also fail to maximally sit over the best structural bone, which is located peripherally in the apophyseal rim of the vertebral body and is formed of the cortex and dense subchondral bone. The configurations of previous implants do not allow for maximizing both the vital surface area over which fusion could occur and the area available to bear the considerable loads present across the spine. Previous implant configurations do not allow for the full utilization of the apophyseal rim bone and the bone adjacent to it, located proximate the perimeter of the vertebral body to support the implants at their leading ends and to maximize the overall support area and area of contact for the implants. The full utilization of this dense peripheral bone would be ideal.
Therefore, there is a need for an interbody spinal fusion implant having opposed portions for placement toward adjacent vertebral bodies that is capable of fitting within the outer boundaries of the vertebral bodies between which the implant is to be inserted and to maximize the surface area of contact of the implant and vertebral bone. The implant should achieve this purpose without interfering with the great vessels or neurological structures adjacent to the vertebrae into which the implant is to be implanted. There exists a further need for an implant that is adapted for placement more fully on the dense cortical bone proximate the perimeter of the vertebral bodies at the implant's leading end.
SUMMARY OF THE INVENTION
The present invention relates to a spinal implant formed or manufactured prior to surgery and provided fully formed to the surgeon for use in interbody fusion formed of bone. The implant is of a width preferably sized to be used in pairs to generally replace all or a great portion of all of the width of the nucleus portion of the disc. To that end, the width of the implant is less than half of the width of the disc space. Preferably, the implant generally has parallel side walls and is used where it is desirable to insert an implant of enhanced length without the leading lateral wall protruding from the spine.
The interbody spinal implant of the present invention is for placement between adjacent vertebral bodies of a human spine across the height of the disc space between those adjacent vertebral bodies. The implant preferably does not extend beyond the outer dimensions of the two vertebral bodies adjacent that disc space and preferably maximizes the area of contact of the implant with the vertebral bone. In a preferred embodiment, the implant has a leading end configured to conform to the anatomic contour of at least a portion of the anterior, posterior, or lateral aspects of the vertebral bodies depending on the intended direction of insertion of the implant, so as to not protrude beyond the curved contours thereof. The implant has an asymmetrical leading end modified to allow for enhanced implant length without the corner of the leading end protruding out of the disc space. As used herein, the phrase “asymmetrical leading end” is defined as the leading end of the implant lacking symmetry from side-to-side along the transverse axis of the implant when the leading end is viewed from a top elevation.
The configuration of the leading end of the implant of the present invention allows for the safe use of an implant of maximum length for the implantation space into which it is installed. Benefits derived from a longer length implant include, but are not limited to, providing a greater surface area for contacting the vertebral bodies and for carrying bone growth promoting materials at the implant surface, increasing the load bearing support area, increased stability, increased internal volume for holding fusion promoting material, and the ability to have a portion of the implant rest upon the apophyseal rim, the best structural bone of the vertebral endplate region. These fusion promoting and bone growth promoting materials may be bone, bone products, bone morphogenetic proteins, mineralizing proteins, genetic materials coding for the production of bone, or any other suitable material.
The spinal implant of the present invention may also include a trailing end opposite the leading end that is configured to conform to the anatomic contour of the anterior, posterior, or lateral aspects of the vertebral bodies, depending on the direction of insertion, so as not to protrude beyond the curved contours thereof. The present invention can benefit interbody spinal fusion implants having spaced apart non-arcuate opposed surfaces adapted to contact and support opposed adjacent vertebral bodies as well as implants having spaced apart arcuate opposed surfaces adapted to penetrably engage opposed vertebral bodies. As used herein, the term “arcuate” refers to the curved configuration of the opposed upper and lower portions of the implant transverse to the longitudinal axis of the implant along at least a portion of the implant's length.
In one embodiment of the present invention, an implant adapted for insertion from the posterior approach of the spine, and for achieving better, safe filling of the posterior to anterior depth of the disc space between two adjacent vertebral bodies, and for the possibility of having the leading end of the implant supported by the structurally superior more peripheral bone including the apophyseal rim and the bone adjacent to it, includes opposed portions adapted to be oriented toward the bone of the adjacent vertebral bodies, a leading end for inserting into the spine, and an opposite trailing end that may be adapted to cooperatively engage a driver. In the alternative, the implant may receive a portion of the driver through the trailing end to cooperatively engage the implant from within and/or at the implant trailing end. The leading end of this embodiment of the implant of the present invention is generally configured to conform to the natural anatomical curvature of the perimeter of the anterior aspect of the vertebral bodies, so that when the implant is fully inserted and properly seated within and across the disc space the implant contacts and supports a greater surface area of the vertebral bone in contact with the implant to provide all the previously identified advantages. Moreover, at the election of the surgeon, the implant of the present invention is configured to be able to be seated upon the more densely compacted bone about the periphery of the vertebral endplates for supporting the load through the implant when installed in or across the height of the intervertebral space.
Related art bone ring implants where the implant is a circle, oval, or oblong have trailing ends that are either modified to be squared-off, or unmodified so as to remain a portion of a circle, an oval, or an oblong and have a medial side wall that is incomplete due to a portion of the medullary canal interrupting the side wall. The present invention implants may have an interior facing medial side wall adapted for placement medially within the disc space with the side wall intact and substantially in the same plane and an exterior facing lateral side wall opposite to the medial side wall and adapted for placement laterally. The implants of the present invention also have a mid-longitudinal axis between the medial and lateral side walls wherein the mid-longitudinal axis at the leading end extends forward-further than the lateral side wall of the leading end while the medial side wall is not equal in length to the lateral side wall, but is greater in length.
In another embodiment of the present invention, an implant for insertion from the anterior approach of the spine and for achieving better filling of the anterior to posterior depth of the disc space has a leading end generally configured to better conform to the natural anatomical curvature of the perimeter of the posterior aspect of the vertebral bodies and does not protrude laterally.
In yet another embodiment of the present invention, the implant has a trailing end that is either asymmetric or symmetric from side-to-side along the transverse axis of the implant. The trailing end may be adapted to conform to the anatomical contours of the anterior or posterior aspects of the vertebral bodies. For example, an implant for insertion from the posterior or anterior approach of the spine has a leading end that is generally configured to better conform to the natural anatomical curvature of at least one of the perimeter of the anterior and posterior aspects, respectively, of the vertebral bodies and a trailing end that is generally configured to conform to the natural anatomical curvature of the opposite one of the posterior and anterior aspects, respectively, of the vertebral bodies depending on the intended direction of insertion and that does not protrude laterally from the vertebral bodies. When the implant is fully seated and properly inserted within and across the disc space, the surface area of the vertebral bone in contact with the implant is more fully utilized.
As another example, an implant in accordance with the present invention for insertion from a translateral approach to the spine and across the transverse width of the vertebral bodies has a leading end that is generally configured to better conform to the natural anatomical curvature of the perimeter of at least one of the lateral aspects, respectively, of the vertebral bodies. The implant also may have a trailing end that is generally configured to conform to the natural anatomical curvature of the opposite one of the lateral aspects, respectively, of the vertebral bodies depending on the intended direction of insertion. Implants for insertion from a translateral approach and methods for inserting implants from a translateral approach are disclosed in Applicant's U.S. Pat. Nos. 5,860,973 and 5,772,661, respectively, incorporated by reference herein.
The implant of the present invention is better able to sit upon the dense compacted bone about the perimeter of the vertebral bodies of the vertebral endplate region for supporting the load through the implant when installed in the intervertebral space. The spinal fusion implants of the present invention has at least one opening therethrough from the upper vertebral body contacting surface through to the lower vertebral body contacting surface to permit for the growth of bone in continuity from adjacent vertebral body to adjacent vertebral body through the implant for fusion across the disc space.
For any of the embodiments of the present invention described herein, the implant preferably includes protrusions or surface roughenings for engaging the bone of the vertebral bodies adjacent to the implant. In a preferred embodiment, the material of the implant is bone that is either in a naturally occurring state, or a composite material made of bone particles. In a naturally occurring state, the implant can be manufactured from a piece of bone obtained from a major long bone or other suitable source and can include bone dowels and diaphyseal bone rings, for example. Alternatively, the implants can be manufactured from a composite of bone made up of cortical fibers, bone filaments, or bone particles, as examples, and at least a second substance preferably bioresorbable such as a plastic or ceramic suitable for the intended purpose. The composite material could be machineable, or moldable, into the desired shape.
Bone offers the advantages of an appropriate modulus of elasticity and strength for the prescribed use, the capacity to be bioactive, including being osteoconductive, osteoinductive, osteogenic, and to more generally provide a good substrate for the formation of new bone as fusion occurs. Further, the bone material being bioabsorable is replaced by the patient's own bone over time preventing stress shielding and leading to the eventual elimination of any foreign body from the implantation site.
In addition to bone, the implants may further include other osteogenic materials such as bone morphogenetic proteins, or other chemical compounds, or genetic material coding for the production of bone, the purpose of which is to induce or otherwise encourage the formation of bone or fusion. In addition to bone, where the implants are of a composite material, they could comprise of a bioresorbable material including, but not limited to various ceramics or plastics. Suitable plastics may include those comprising lactides, galactides, glycolide, capronlactone, trimethylene carbonate, dioxanone, in various polymers and/or combinations.
Materials other than bone for use as the base material used to form the implant are specifically excluded from the definition of implant materials for the purpose of this application. The implants may be adapted to receive fusion promoting substances within them such as cancellous bone, bone derived products, or others.
It is appreciated that the features of the implant of the present invention as described herein are applicable to various embodiments of the present invention including implants having non-arcuate or arcuate upper and lower opposed portions adapted to be oriented toward the bone of the adjacent vertebral bodies.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a horizontal cross-section through a boney endplate region of a vertebral body.
FIGS. 2-3 are top plan views of the fourth lumbar and first sacral vertebral bodies, respectively, in relationship to the blood vessels located anteriorly thereto.
FIG. 4 is a top plan plan view of an endplate region of a vertebral body with a prior art implant on the left side of the center line and an implant in accordance with one embodiment of the present invention on the right side of the centerline inserted from the posterior aspect of the spine.
FIG. 5 is a side perspective view of the outline of an implant in accordance with one embodiment of the present invention.
FIG. 6 is a partial enlarged fragmentary view along line 6 — 6 of FIG. 5 .
FIG. 7 is a top plan view of a lumbar vertebral body in relationship to the blood vessels located proximate thereto and an implant in accordance with one embodiment of the present invention inserted from the posterior aspect of the vertebral body.
FIG. 8 is a top plan view of a lumbar vertebral body in relationship to the blood vessels located proximate thereto and an implant in accordance with one embodiment of the present invention inserted from the anterior aspect of the vertebral body.
FIG. 9 is a top plan view of an implant in accordance with one embodiment of the present invention illustrating the mid-longitudinal axis and a plane bisecting the mid-longitudinal axis along the length of the implant.
FIG. 10 is a top plan view of a lumbar vertebral body in relationship to the blood vessels located proximate thereto and an implant having arcuate upper and lower opposed portions in accordance with an embodiment of the present invention inserted from the posterior aspect of the vertebral body.
FIG. 11 is a trailing end view of a spinal implant shown in FIG. 10 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 4 shows an embodiment of the present invention comprising an interbody spinal implant generally referred by the numeral 100 , inserted in the direction of arrow P from the posterior aspect of a vertebral body V on one side of the centerline M in the lumbar spine. In a preferred embodiment of the present invention, the implant can be made of bone that is either in a naturally occurring state, or can be made of a composite material comprising bone particles. In a naturally occurring state, the implant can be manufactured from a piece of bone obtained from a major long bone or other suitable source and can include bone dowels and diaphyseal bone rings, for example. Alternatively, the implants can be manufactured from a composite of bone made up of cortical fibers, bone filaments, bone particles, as examples. In addition to bone, the composite may also include a material which may or may not be bioactive and/or bioresorbable such as a plastic, ceramic, or other. Once formed, the bone composite implant could be machineable, or moldable, into the desired shape.
In addition to bone, the implants may further include other osteogenic materials such as bone morphogenetic proteins, or other chemical compounds, or genetic material coding for the production of bone, the purpose of which is to induce or otherwise encourage the formation of bone or fusion. In addition to bone, the implants could comprise a bioresorbable material including, but not limited to cortical bone, plastics and composite plastics. Suitable plastics may include those comprising lactides, galactides, glycolide, capronlactone, trimethylene carbonate, dioxanone in various polymers and/or combinations.
Implant 100 has a leading end 102 for insertion into the disc space and an opposite trailing end 104 . In a preferred embodiment, leading end 102 is configured to not extend beyond the outer dimensions of the two vertebral bodies adjacent the disc space proximate leading end 102 after implant 100 is installed, to maximize the area of contact of the implant with the vertebral bone. Leading end 102 could be described as being generally configured to generally conform to at least a portion of the natural anatomical curvature of the aspect of the vertebral bodies adjacent the disc space proximate leading end 102 after implant 100 is installed. The general configuration of leading end 102 is further described in connection with FIG. 9 below.
As shown in FIGS. 7 and 8 , depending on the direction of insertion, for example, when implant 100 is installed in the direction of arrow P from the posterior aspect of the vertebral body V, leading end 102 a is adapted to conform to at least a portion of the anterior aspect of the vertebral body V. When implant 100 is installed in the direction of arrow A from the anterior aspect of vertebral body V, leading end 102 b is adapted to conform to at least a portion of the posterior aspect of vertebral body V. Trailing end 104 may be symmetrical or asymmetrical from side-to-side along the transverse axis of the implant and can conform to at least a portion of the natural curvature of the aspect of vertebral body V opposite to leading end 102 . Trailing end 104 may or may not be configured to conform to the aspect of vertebral body V proximate trailing end 104 after implant 100 is installed. Trailing end 104 need only have a configuration suitable for its intended use in the spine.
As shown in FIGS. 5 and 6 , implant 100 has opposed portions 106 and 108 that are adapted to contact and support adjacent vertebral bodies when inserted across the intervertebral space. In this embodiment, opposed portions 106 , 108 have a non-arcuate configuration transverse to the longitudinal axis of implant 100 along at least a portion of the length of implant 100 . Opposed portions 106 , 108 are spaced apart and connected by an interior side wall 112 and an exterior side wall 114 opposite interior side wall 112 . Interior side wall 112 is the portion of implant 100 adapted to be placed toward another implant when implant 100 is inserted in pairs into the disc space between the adjacent vertebral bodies to be fused. Interior side wall 112 is not the internal surface of a hollow interior of implant 100 . Exterior side wall 114 is adapted to be placed into the disc space nearer to the perimeter of the vertebral bodies than interior side wall 112 . Side walls 112 , 114 are preferably continuous from leading end to trailing end. Sidewalls 112 , 114 may also include at least one opening for permitting for the growth of bone therethrough.
Preferably, each of the opposed portions 106 , 108 have at least one opening 110 in communication with one another to permit for the growth of bone in continuity from adjacent vertebral body to adjacent vertebral body and through implant 100 . Opening 110 is preferably a through-hole with a maximum cross-sectional dimension greater than 0.5 mm between interior side wall 112 and exterior side wall 114 passing completely through the implant and is preferably adapted to hold bone growth promoting material for permitting for the growth of bone from vertebral body to vertebral body through the implant. The perimeter of the through-hole is preferably continuous and uninterrupted. Implant 100 may further be hollow or at least in part hollow. Implant 100 may also include surface roughenings on for example, at least a portion of opposed portions 106 , 108 for engaging the bone of the adjacent vertebral bodies.
As illustrated in FIG. 9 , implant 100 has a mid-longitudinal axis MLA along its length. Mid-longitudinal axis MLA is bisected by a plane BPP perpendicular to and bisecting the length of implant 100 along the mid-longitudinal axis MLA. Implant 100 has a first distance as measured from point C at leading end 102 to bisecting perpendicular plane BPP at point E that is greater than a second distance as measured from bisecting perpendicular plane BPP at point F to the junction of leading end 102 and exterior side wall 114 at point B. Implant 100 has a third distance as measured from point A at the junction of leading end 102 and interior side wall 112 to bisecting perpendicular plane BPP at point D that is greater than the second distance as measured from at point F to point B. While in the preferred embodiment as shown in FIG. 9 , the third distance from points A to D is illustrated as being longer than the first distance from points C to E, the third distance can be equal to or less than the first distance. Ina preferred embodiment, the first distance measured from points C to E is greater than the second distance measured from points B to F; the third distance measured from points A to D can be less than the first distance measured from points C to E; and the third distance measured from points A to D does not equal the second distance measured from points B to F.
In a preferred embodiment of the present invention, when implant 100 is inserted between two adjacent vertebral bodies, implant 100 is contained completely within the vertebral bodies so as not to protrude from the spine. Specifically, the most lateral aspect of the implanted implant at the leading end has been relieved, foreshortened, or contoured so as to allow the remainder of the implant to be safely enlarged so as to be larger overall than the prior implants without the leading end lateral wall protruding from the disc space. Although overall enlargement of the implant is a preferred feature of one embodiment of the present invention, it is not a requisite element of the invention.
While a preferred embodiment of the present invention has been illustrated and described herein in the form of an implant having non-arcuate upper and lower portions along a portion of the length of the implant, another preferred embodiment of the present invention as best shown in FIG. 10 includes an implant having arcuate upper and lower portions along at least a portion of the length of the implant. All of the features described in association with the non-arcuate embodiments are equally applicable to the arcuate embodiments of the present invention.
FIGS. 10-11 show two interbody spinal implants generally referred to by the numeral 200 , inserted in the direction of arrow P from the posterior aspect of a vertebral body V, one on either side of the centerline M in the lumbar spine. Implant 200 is non-threaded and is configured for linear insertion into the disc space in a direction along the mid-longitudinal axis of implant 200 . Implant 200 has a leading end 202 for insertion into the disc space and an opposite trailing end 204 . In a preferred embodiment, leading end 202 is configured to not extend beyond the outer dimensions of the two vertebral bodies adjacent the disc space proximate leading end 202 after implant 200 is installed, to maximize the area of contact of the implant with the vertebral bone. Leading end 202 could be described as being generally configured to generally conform to at least a portion of the natural anatomical curvature of the aspect of the vertebral bodies adjacent the disc space proximate leading end 202 after implant 200 is installed. In a preferred embodiment, less than half of asymmetric leading end 202 is along a line perpendicular to the mid-longitudinal axis of the implant in a plane dividing the implant into an upper half and a lower half.
In a further preferred embodiment of either arcuate or non-arcuate implants, more than half of the leading end can be a contour that goes from the exterior side wall toward the mid-longitudinal axis of the implant in the plane dividing the implant into an upper half and a lower half. In another preferred embodiment of either arcuate or non-arcuate implants, the leading end includes a curve that extends from the exterior side wall beyond the mid-longitudinal axis of the implant. The more pronounced curve of the leading end of the implant of the present invention as compared to the chamfer of related art implants advantageously provides for closer placement of the implant's leading end to the perimeter of the vertebral body, without the limiting corner protruding therefrom, to more fully utilize the dense cortical bone in the perimeter of the vertebral bodies. The configuration of the implant of the present invention provides the use of an implant having a longer overall length as measured from leading end to trailing end for a better fill of the disc space.
Implant 200 has opposed portions 206 and 208 that are arcuate transverse to the longitudinal axis of implant 200 along at least a portion of the length of implant 200 and are adapted to contact and support adjacent vertebral bodies when inserted across the intervertebral space and into the vertebral bodies. Implant 200 can further include protrusions or surface roughenings such as ratchetings 220 for enhancing stability. Surface roughenings may also include ridges, knurling and the like.
The present invention is not limited to use in the lumbar spine and is useful throughout the spine. In regard to use in the cervical spine, by way of example, in addition to various blood vessels the esophagus and trachea also should be avoided.
Further, the implant of the present invention preferably includes non-arcuate opposed surface portions that are either generally parallel to one another along the length of the implant or in angular relationship to each other such that the opposed surfaces are closer to each other proximate one end of the implant than at the longitudinally opposite other. The spinal implant of the present invention allows for a variable surface, or any other configuration and relationship of the opposed surfaces.
Implant 100 may be adapted to cooperatively engage a driver instrument for installation of the implant into the recipient site. For example, in a preferred embodiment trailing end 104 may be configured to complementary engage an instrument for driving implant 100 .
While the exact contour and/or curvature of a particular vertebral body may not be known, the teaching of having the implant leading end be arcuate or truncated along one side (the lateral leading end) or from side to side so as to eliminate the length limiting lateral leading corner LC or the side wall or lateral aspect junction to the implant leading end is of such benefit that minor differences do not detract from its utility. Further, the range of describable curvatures may be varied proportionately with the size of the implants as well as their intended location within the spine and direction of insertion to be most appropriate and is easily determinable by those of ordinary skill in the art.
Generally for use in the lumbar spine, and where the leading end is a portion of a circle, then the arc of radius of the curvature of the leading end of the implant should be from 10-30 mm to be of greatest benefit, though it could be greater or less, and still be beneficial. The same is true for the cervical spine where the arc of radius is preferably 8-20 mm. While particular preferred embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects.
While specific innovative features were presented in reference to specific examples, they are just examples, and it should be understood that various combinations of these innovative features beyond those specifically shown are taught such that they may now be easily alternatively combined and are hereby anticipated and claimed.
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An interbody spinal implant is formed of cortical bone adapted for placement across an intervertebral space formed across the height of a disc space between two adjacent vertebral bodies. An asymmetrical leading end on the implant is adapted to sit upon the peripheral areas, such as the apophyseal rim and the apophyseal rim area, of the vertebral end plate region of the vertebral bodies without protruding therefrom. The asymmetrical leading end allows for the safe use of an implant of maximum length for the implantation space into which it is installed. The implant can also include an asymmetric trailing end adapted to sit upon the more peripheral areas of the vertebral end plate region of the vertebral bodies.
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BACKGROUND OF THE INVENTION
The invention relates to a display device comprising an electro-optical display medium between two supporting plates, a system of picture elements arranged in rows and columns, with each picture element being formed by picture electrodes arranged on the facing surfaces of the supporting plates, and a system of row and column electrodes for presenting selection and data signals by means of which a range of voltages dependent on the electro-optical display medium can be presented across the picture elements for the purpose of picture display.
A display device of this type is suitable for displaying alphanumerical information and video information by means of passive elector-optical display media such as liquid crystals, electrophoretic suspensions and electrochromic materials.
A display device ofthe type described in the opening paragraph is known from U.S. Pat. No. 4,811,006, issued March, 1989, in the name of the Applicant. In the device shown in this Application diodes are used as non-linear switching elements in an active matrix, namely two diodes per picture element. Two successive rows of picture elements each time have one row electrode in common. The drive mode is such that in television applications (for example, with a drive mode in accordance with the PAL or NTSC system) the information of two successive even and odd lines is presented across each picture element at an alternating polarity and at the field frequency. The information of a picture element is therefore determined by the average signal of two successive even and odd lines. Since each time two rows of picture electrodes are simultaneously written, because two successive rows each time have one row electrode in common, such a device provides little flexibility as regards the choice of colour filters to be used. In fact, this choice is limited to strip-shaped colour filters.
U.S. patent application Ser. No. 208,185, filed Jun. 16, 1988; in the name of the Applicant describes a picture display device of the type mentioned in the opening paragraph in which the row electrodes are not common and in which the rows of picture elements are separately driven without the omission of common row electrodes, leading to an increase of the number of connections.
This ensures a considerable freedom in the choice of the colour filters to be used.
This is possible by giving the picture elements a given adjustment per row by charging or discharging the capacitances associated with these picture elements after first having discharged or charged them too far (whether or not accurately).
To this end such a picture display device comprises means to apply, prior to selection, an auxiliary voltage across the picture elements beyond or on the limit of the voltage range to be used for picture display.
In the embodiment shown in the said Patent Application diodes are used as non-linear switching elements.
OBJECT AND SUMMARY OF THE INVENTION
The present invention has for its object to provide a device of the type described in the opening paragraph having a high yield which is also realized by the fact that a satisfactorily operating switching unit is substantially always present.
The invention is based on the recognition that this can be achieved with redundancy-increasing measures known per se without affecting the operation of the display device, notably with respect to grey scale adjustment.
To this end a device according to the invention is characterized in that the picture electrodes on one of the supporting plates are electrically connected to the common point of two non-linear switching units which are arranged in series between a column electrode for data signals and an electrode for applying, prior to selection, a reference voltage resulting in; an auxiliary voltage across the picture elements beyond or on the limit of the voltage range to be used for picture display, while at least one non-linear switching unit comprises a plurality of non-linear switching elements.
As a result of such built-in redundancy, it appears that the risk of faulty switching units is reduced by a factor of 100 to 1000 and that the yield is increased by the same factor in the manufacture of such a display device.
The switching units may comprise series arrangements or parallel arrangements of non-linear switching elements, but also combinations thereof.
The auxiliary voltage is, for example, a fixed reference voltage so that all picture elements in a row are first charged negatively or positively to a fixed value and are subsequently charged or discharged to the correct signal value, dependent on the data signals presented.
Since this is effected for each individual row without a subsequent row or a previous row being influenced, the picture information can be adapted to a colour filter to be used, which colour filter may be composed of, for example, triplets as described, for example, in U.S. Pat. No. 4,908,609 in the name of the Applicant, or it may have, for example, a diagonal structure.
Discharging and charging prior to the actual driving operation with the picture information can be effected during the same line period in which the picture information is presented, but also during the preceding line period.
Since each row of picture elements is now separately written, the voltage across these picture elements can also be inverted per row, which leads to a higher face-flicker frequency and hence to a steadier picture.
BRIEF DESCRIPTION OF THE DRAWING
The invention will now be described in greater detail, by way of example, with reference to the accompanying drawings in which
FIG. 1 is a diagrammatic cross-section of a portion of an electro-optic display device, taken on the line I--I in FIG. 2;
FIG. 2 is a diagrammatic plan view of the device of FIG. 1;
FIG. 3 shows the associated transmission/voltage characteristic of a display cell of the device of FIG. 1;
FIG. 4a and 4b are diagrammatic schematic representations of a device of the type shown in FIGS. 1 and 2;
FIG. 5 is a diagrammatic representation of some appropriate drive signals for operation of such a device;
FIG. 6 shows a modification of the arrangement of FIG. 4a;
FIG. 7 shows a first modification of the arrangement of FIG. 4a using redundancy measures according to the invention;
FIG. 8 shows a second modification according to the invention, and
FIG. 9 shows another transmission/voltage characteristic of a display cell.
The Figures are diagrammatic and not to scale. Corresponding components are usually denoted by the same reference numerals.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 show in a diagrammatic cross-section and in a plan view respectively, a part of a liquid crystal display device 1, which has two supporting plates 2 and 3, between which, for example, a twisted nematic or a ferro-electric liquid crystalline material 4 is present. The inner surfaces of the supporting plates 2 and 3 have electrically and chemically insulating layers 5. A plurality of row and column-arranged picture electrodes 6 of indium tin oxide or another electrically conducting transparent material is provided on the supporting plate 2. Likewise, transparent counter electrodes 7 of, for example, indium tin oxide which are in the form of strip-shaped row electrodes 11, are provided on the supporting plate 3. The facing picture electrodes 6, 7 form individually controllable display cells which constitute the picture elements of the display device.
Strip-shaped column electrodes 8 are arranged between the columns of picture electrodes 6. Each picture electrode 6 is connected to a column electrode 8 by means of a switching unit, in this embodiment a diode 9 diagrammatically shown in FIG. 2. As is apparent from FIG. 2, the associated column electrodes 8a, 8b are arranged between two picture electrodes 6a, 6b. Liquid crystal orienting layers 10 are also provided on the inner surfaces of the supporting plates 2 and 3 over the various electrodes. As is known, another orientation state of the liquid crystal molecules and hence an optically different state can be obtained by applying a voltage across the liquid crystal layer 4. As is also known, the display device may be realized as a transmissive or a reflective device and may be provided with one or two polarizers for this purpose.
Auxiliary electrodes 18, each of which has two picture electrodes 6 in common in this embodiment, are arranged on the side of the picture electrodes 6 opposite from that of the column electrodes 8. The auxiliary electrodes 18 connect the picture electrodes 6 to a reference voltage via other switching units, in this embodiment diodes 19, which are diagrammatically shown in FIG. 2. This reference voltage is chosen to be such that, dependent on the voltages used on the selection line (counter electrodes 11) and the electro-optical material used, the capacitance associated with the picture element can always be discharged via the diode 19 to a voltage value beyond or on the limit of the range of transition in the transmission/voltage characteristic of the relevant electro-optical material.
FIG. 3 shows diagrammatically a transmission/voltage characteristic of a display cell as it occurs in the display device of FIGS. 1, 2. Below a given threshold voltage (V 1 or V th ) the cell substantially passes no light, whereas above a given saturation voltage (V 2 or V sat ) the cell is substantially entirely transparent. The intermediate range constitutes the above-mentioned range of transition and is indicated in FIG. 3 by bracket 17. In this respect it is to be noted that the absolute value of the voltage is plotted on the abscissa, because such cells are usually driven at an alternating voltage.
FIGS. 4a and 4b show diagrammatically a display device of the type shown in FIGS. 1, 2. Picture elements 12 constituted by facing picture electrodes 6 and row electrodes 7, 11 at one end, which together with the column electrodes 8 are arranged in the form of a matrix. The picture elements 12 are connected to column electrodes 8 via diodes 9. They are also connected via diodes 19 to an auxiliary electrode 18, which is common to two diodes 19, 19'.
FIGS. 5a-c show how the drive signals are chosen for a plurality of rows of picture elements 12 in order to write them with picture information which changes sign during each field (for example, in TV applications).
For writing information, a first selection voltage V s1 (see FIG. 5a) is presented on a selection line 11 during a selection period t s , while the information or data voltages V d are simultaneously presented on the column electrodes 8; this leads to a positive voltage across a picture element 12 which represents the information presented.
To prevent degradation of the liquid crystal and to be able to increase the so-called face-flicker frequency, information having an alternating sign is preferably presented across the picture element 12. In a device according to the invention a negative voltage across the picture element 12, which represents the information presented, is achieved by presenting a second selection voltage V s2 while simultaneously presenting inverted data voltages (-V d ) after having discharged the capacitance associated with the picture element 12 too far (or having negatively charged it too far).
From the instant t 0 (see FIG. 5a) a selection voltage V s1 is presented on a row electrode 11 during a selection period t s (which in this example is chosen to be equal to a line period for TV applications, namely 64 μsec) while information voltages or data voltages V d are simultaneously presented on the column electrodes 8. After the instant t 1 the row of picture elements 12 is no longer selected because the row electrode 11 receives a voltage V ns1 . This voltage is maintained until just before the next selection of the row of picture elements 12. In this example this is effected by giving the selection line 11 a reset voltage just before selecting the first row of picture elements 12 again, namely at an instant t 3 =t f -t s in which t f represents a field period. The reset voltage and a reference voltage presented on the common point of the diodes 9, 19' can then be chosen to be such that the picture elements 12 are charged negatively to such an extent that the voltage across the row of picture elements lies beyond the range to be used for picture display (to a value of ≦-V sat ). In a subsequent selection period (from t 4 ) they are then charged to the desired value determined by data voltages -V d . To this end the row electrodes receive the voltage V s2 and after the selection period (after t 5 ) has elapsed, they receive a non-selection voltage V ns2 . In this way the voltage across the picture elements is inverted during each field period.
FIG. 5b shows the same voltage variation as FIG. 5a, but is then shifted over a field period plus a selection period (in this case a line period). This provides the possibility of writing two successive rows of picture elements with inverse data voltages with respect to each other. FIG. 5c is identical to FIG. 5a, but is shifted over two selection periods.
For (television) pictures with half the vertical resolution in which the lines of the even and the odd field are written over each other, it is achieved that the picture information changes its sign and is refreshed once per field period. Although the line-flicker frequency is 25 Hz (30 Hz) in this case, a face-flicker frequency of 50 Hz (60 Hz) is achieved between successive rows due to the phase difference of 180° introduced by changing the sign per row.
The selection voltages V s1 and V s2 may of course also be chosen to be shorter than one line period (64 μsec). In this case the reset voltage may alternatively be presented during a part of the line period in which selection takes place, provided there is sufficient time left to charge the picture elements 12. The voltage variation on the electrodes 11 is then effected, for example, in the way as shown diagrammatically in FIG. 5a by means of the broken line 14.
The device shown is very suitable for using a drive method in which the average voltage across a picture element ##EQU1## (see FIG. 3) so that the absolute value of the voltage for the purpose of picture display across the picture elements 12 is substantially limited to the range between V th and V sat .
A satisfactory operation as regards grey scales is obtained if, dependent on the data voltages V d on the column electrodes 8, the voltage values across the picture elements 12 are at most V c +V dmax =V sat and at least V c -V dmax =V th . Elimination of V c yields: |V d | max =1/2(V sat -V th ), that is to say, -1/2(V sat -V th )≦V dmax ≦1/2(V sat -V th ).
In order to charge a row of picture elements 12, for example, positively, the associated row electrode 11 is given a selection voltage V s1 =-V on -1/2(V sat +V th ) in which V on is the forward voltage of the diode 9. The voltage across the picture element 12 is therefore V d -V on -V si ; it ranges between
-1/2(V sat -V th )+1/2(V sat +V th )=V th
and
1/2(V sat -V th )+1/2(V sat +V th )=V sat ,
dependent on V d .
In order to negatively charge the same row of picture elements 12 (in a subsequent field or frame period) at a subsequent selection with inverted data voltages, these are first charged negatively too far by means of a reset voltage V reset on the row electrode 11 via diodes 19 connected to the reference voltage. Subsequently the selected row electrode receives a selection voltage V s2 =V on +1/2(V sat +V th ) (in the same line period or in a subsequent line period). The picture elements 12 which are negatively charged too far are now charged via the diodes 9 to V d -V on -V s2 , that is to say, to values between
-1/2(V sat -V th )-1/2(V sat -V th )=-V sat
and
1/2(V sat -V th )-1/2(V sat -V th )=-V th ,
so that information with the opposite sign is presented across the picture elements 12.
In the case of non-selection the requirement must be satisfied that neither diodes 9 nor diodes 19 can conduct, in other words, for the voltage V A at the junction point 13 it must hold that V a ≧V d and V A ≦V ref or V Amin ≧V Dmax (1) and V Amax ≦V ref (2).
For the lowest non-selection voltage V ns1 it then holds that
(1) V Amin =V ns1 +V th ≧V Dmax =1/2(V sat -V th ),
or
V ns1 ≧1/2(V sat -V th )-V th (3).
It follows from (2) that:
V ns1 +V sat ≦V ref or
V ns1 ≦V ref -V sat (4).
Combination of (3) and (4) yields:
V ref -V sat ≧V ns1 ≧1/2(V sat -V th )-V th
V ref ≧3/2(V sat -V th ) (5).
For the highest non-selection voltage V ns2 it similarly holds that:
V Amin =V ns2 -V sat ≧1/2(V sat -V th ) or
V ns2 ≧1/2(V sat -V th )+V sat (3') and
V ns2 -V th ≦V ref or V ns2 ≦V ref +V th (4').
Combination of (3') and (4') yields:
V ref +V th ≧V ns2 ≧1/2(V sat -V th )+V sat or
V ref ≧3/2(V sat -V th ) (5).
The reference voltage 3/2(V sat -V th ) thus suffices to block the diodes 19, 19' after writing both data and inverted data by the method described above. In summary it holds for the voltages V ns1 , V s1 , V ref and V reset that:
V s1 =-V on -1/2(V sat +V th );
V s2 =-V on +1/2(V sat +V th );
V ns1 =1/2(V sat -V th )-V th ;
V ns2 =1/2(V sat -V th )+V sat ;
V ref =3/2(V sat -V th );
V res =V on +5/2 V sat -3/2 V th .
When reversing the sign of the diodes 9, 19 as is diagrammatically shown in FIG. 4a, the same type of drive mode may be used. Similar relations, be it with reversed sign, then apply to the drive signals.
FIG. 6 shows diagrammatically a modification of the device of FIG. 4a in which per column of picture elements both a column electrode 8 and an auxiliary electrode 18 is present. Otherwise the reference numerals have the same significance as in the previous embodiment. The drive mode is also identical.
As has been stated, the advantage of such a device is, inter alia, that each row of picture elements can be separately driven without extra connection lines being required and with a free choice as regards the colour filters to be used.
In the embodiments described above the devices comprise two switching units, in this case the diodes 9, 19, for each picture element 12. To reduce the risk of poorly functioning picture elements due to non-functioning or poorly functioning switching elements, redundancy is used; for example, two diodes may be arranged in parallel to neutralize the consequences of open connections and two diodes may be arranged in series to neutralize the consequences of a short-circuited diode.
FIG. 7 shows a way in which for a single picture element 12 a switching unit 21 connects the picture element 12 to the auxiliary electrode 18 for the reference voltage. The switching unit comprises two series-arranged diodes 19a, 19b. The reference voltage is adapted in such a way that despite the additional voltage drop across the second diode the picture elements can be negatively charged so far that the voltage across the picture elements lies again beyond the range to be used for picture display (up to a value of ≦-V sat ) and is subsequently charged to the desired value in the same way as described with reference to FIGS. 4 and 5. If one of the diodes 19a, 19b is short-circuited, the relevant picture element 12 is negatively charged to a slightly further extent, but is still charged to the desired value in the subsequent selection period. Hence, such a short circuit does not affect the operation of the display device.
Another error which may occur is an open connection. This can be neutralized by arranging one or more switching elements in parallel with the diode circuit.
This is diagrammatically indicated by means of the diodes 22a, 22b in the relevant embodiment.
In FIG. 8, switching units 9a, 9b, in this embodiment diodes, are arranged in the switching unit 23 so as to neutralize the consequences of a short-circuited diode. In order to cope with the effect of an additional diode in the switching unit, the above-derived selection voltages (for the configuration of FIG. 4a) must be corrected by an amount of -V on , both when charging the display element negatively and when charging it positively.
If one of the diodes 9a, 9b is short-circuited, the picture element 12 is charged too far by an amount of V on during positive charging, but is charged too little in an absolute sense by the same amount V on during negative charging. This is shown diagrammatically in FIG. 9. In this Figure the reference P i is the desired setting value of the grey scale associated with a voltage V i ; the references P p and P n denote the values achieved in practice during positive and negative writing, respectively, when one of the diodes 9a, 9b is short-circuited. Thus the picture element 12 flickers. However, it has been found that flicker of a single picture element is invisible or is hardly visible. Moreover, if two frames are averaged, the effective value of the voltage across the picture element is substantially equal to the desired value.
The grey scale to be set is approached all the better as the voltage drop in the forward direction across the diodes is smaller by an amount of V on . Consequently, Schottky diodes (V on ≈0.3 V) are preferably used for this purpose, but pin diodes (V on ≈0.8 V) are alternatively suitable.
To neutralize the consequences of open connections, diodes 24a, 24b may be arranged in parallel in the same way as for switching unit 21. However, the forward characteristic of the switching unit 23 changes if one of the branches fails. This change is of the order of 18 mV for Schottky diodes. For a typical liquid crystal material (ZLI 84.460) V th =1.5 Volt and V sat =3.6 Volt. The change in this case is only 1/83 of the full range (V sat -V th =2.1 V) and is thus substantially negligible.
If the open connections prevail, for example, because contact holes are so small that they cannot be etched open during manufacture, it is also possible to manufacture larger diodes having larger contact holes.
The above-described measures of providing redundancy in the switching units may lead to a considerably higher yield (an improvement by a factor of 100 to 1000).
The invention is of course not limited to the embodiments shown, but several variations are possible within the scope of the invention.
Non-linear switching elements other than diodes are suitable such as, for example, bipolar transistors with shortcircuited base-collector junctions or MOS transistors whose gate is short-circuited with the drain zone. There are also various possibilities for the diodes themselves. In addition to the diodes which are conventionally used in the technology for display devices, for example, a pn diode, Schottky diode or pin diode formed in monocrystalline, polycrystalline or amorphous silicon, CdSe or another semiconductor material may be considered, while the diodes may be formed both in the vertical and lateral configurations.
Moreover, the availability of a reset voltage renders the above-described device particularly suitable for use in a ferroelectric display medium as described in U.S. Pat. No. 4,840,462 in the name of the Applicant.
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In a picture display device driven with an active matrix the voltage across the picture elements is accurately adjusted by discharging or charging the associated capacitances, if necessary, first to beyond the transition range in the transmission/voltage characteristic. Redundancy is advantageously used in the switching units employed for this purpose.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to porous fibrous sheets, such as papers and nonwoven fabrics, which comprise nanofibers or a combination of wood pulp and nanofibers.
2. Description of the Related Art
Barrier to microbial penetration is an important and essential property of materials used for packaging medical devices. Materials currently used in medical packaging include a variety of films, flash-spun polyolefin nonwovens, and medical grade papers. In cases where gas or plasma sterilization (e.g., ethylene oxide, Sterrad®, etc.) is used to sterilize the contents of a package, the package generally includes a film, such as a thermoformed film, forming the bottom web that is heat-sealed to a porous and gas permeable lid, such as paper or flash-spun polyolefin sheet. Alternately, the package may be in the form of a pouch comprising a porous layer heat-sealed to a film. The porous lid or layer must allow the sterilant gas or plasma to enter and exit the package to sterilize its contents and at the same time provide a barrier to microbial penetration in order for the medical device to remain sterile until it is used.
The microbial barrier properties of a porous fibrous sheet depend on the average pore size, sheet thickness, size of fibers, fiber morphology, etc. Porous microbial barrier sheets prevent penetration by microbial spores and particles that range in size from sub-micrometer to a few micrometers. The ability of porous sheets to prevent bacterial penetration is measured by their Log Reduction Value (LRV). The higher the LRV value, the better a material is in preventing microbial penetration of the package. For example, the LRV of flash-spun polyolefin sheets used in medical packaging ranges between about 3.2 and 5.5 or higher, as the basis weight (BW) increases from about 1.65 to 2.2 oz/yd 2 (55.9 to 74.6 g/m 2 ). Medical grade papers known in the art have LRV's between about 1 and 3, depending on their basis weight, pore size, additive treatments, etc., and are much less effective as microbial barriers than flash-spun materials. Although paper has been improved through many years of use in medical packaging, it still has further limitations in strength, tear resistance and also peelability. Special peelable coatings are used such that they form the weak link in heat sealed packages and tend to fail cohesively when packages are peeled to avoid tearing the paper, which results in linting of the medical device.
Koslow, Patent Application Publication No. U.S. 2003/0177909 describes an air filter medium comprising nanofibers. A coating of nanofibers can be used to enhance the performance of filter media. The nanofibers are preferably fibrillated nanofibers. In one embodiment a filter medium is prepared from a blend of fibrillated nanofibers and glass microfibers.
Generally, increasing the basis weight can increase the barrier properties of nonwoven webs. It would be desirable to improve the barrier properties in a cost-effective manner without increasing basis weight or changing the nonwoven properties that control their porosity and breathability. There remains a need for porous fibrous sheet structures having improved microbial barrier properties for use in medical packaging.
SUMMARY OF THE INVENTION
One embodiment of this invention is a porous fibrous sheet for medical packaging comprising nanofibers having a diameter in the range of about 10 nm to about 1000 nm.
One embodiment of this invention is a porous fibrous sheet comprising between about 1 weight percent and 99 weight percent nanofibers and between about 99 and 1 weight percent wood pulp, based on the total combined weight of nanofibers and wood pulp in the fibrous sheet having an LRV of at least 1.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed to porous fibrous sheets, including papers and nonwoven fabrics that comprise nanofibers or a nanofiber/wood pulp combination. The fibrous sheets have improved barrier properties at substantially the same basis weight as similar fibrous sheets that do not contain nanofibers. Certain porous fibrous sheets of the present invention are useful as microbial barrier materials, for example in lidding for medical packaging.
The term “nanofiber” as used herein refers to fibers having a diameter or cross-section between about 10 nanometers (nm) and 1000 nm (1 micrometer), preferably between about 200 and 400 nm and more preferably less than 200 nm. The term diameter as used herein will include the greatest cross-section of non-round shapes.
The term “lyocell fibers” as used herein refers to fibers that are formed by spinning of a solution that is obtained by dissolving wood pulp in an organic solvent, such as an amine oxide. Methods for manufacture of lyocell fibers are known in the art. “Wood pulp” as used herein refers to the product of boiling wood chips with alkaline liquors or solutions of acidic or neutral salts followed by bleaching with chlorine compounds, the object being to remove more or less completely the hemicelluloses and lignin incrustants of the wood.
The term “polyester” as used herein is intended to embrace polymers wherein at least 85% of the recurring units are condensation products of dicarboxylic acids and dihydroxy alcohols with linkages created by formation of ester units. This includes aromatic, aliphatic, saturated, and unsaturated di-acids and di-alcohols. The term “polyester” as used herein also includes copolymers (such as block, graft, random, and alternating copolymers), blends, and modifications thereof. Examples of polyesters include poly(ethylene terephthalate) (PET), which is a condensation product of ethylene glycol and terephthalic acid, and poly(1,3-propylene terephthalate), which is a condensation product of 1,3-propanediol and terephthalic acid.
The terms “nonwoven fabric, sheet, layer, or web” as used herein means a structure of individual fibers, filaments, or threads that are positioned in a random manner to form a planar material without an identifiable pattern, as opposed to a knitted or woven fabric. Examples of nonwoven fabrics include meltblown webs, spunbond webs, carded webs, air-laid webs, wet-laid webs, spunlaced webs, and composite webs comprising more than one nonwoven layer.
Nanofibers suitable for use in the present invention include organic or inorganic nanofibers including, but not limited to, nanofibers made from polymers, engineered resins, ceramics, cellulose, rayon, glass, metal, activated alumina, carbon or activated carbon, silica, zeolites, or combinations thereof.
The nanofibers are preferably fibrillated nanofibers, such as those described in Koslow, Patent Application Publication No. U.S. 2003/0177909, which is hereby incorporated by reference. Fibers that can be fibrillated to form nanofibers include lyocell fibers and select grades of acrylic, nylon, or other synthetic fibers of incomplete crystallinity. Fibrillation is the peeling back or splintering of the fiber ends to form tiny “hairs” on the surface of the fiber. If the fiber is likened to a banana, small fibrils or sections of the fiber splinter and pull away like a banana peel. Fibrillated nanofibers can be prepared by subjecting fibrillatable fibers, such as chopped fiber tow, having a length between about 1 and 10 mm to repetitive stresses while minimizing further reduction in fiber length. The preferred weight weighted mean length for fibrillated nanofibers should be less than about 4 mm. For example, the fibers can be fibrillated in water in a device such as a blender, or in beater or refiner machines known in the art.
As the fibers undergo these stresses, the fibers form fibrils (“hairs”) as a result of weaknesses between amorphous and crystalline regions to form nanofibers. Samples of the resulting fibrillated pulp can be removed from the fibrillating process at intervals and analyzed to determine when the desired fiber diameter, generally between 10 nm and 1000 nm, is achieved. Samples of fibrillated nanofibers (after drying) can be mounted on appropriate holders and inserted in a Scanning Electron Microscope (SEM). Fiber dimensions can be measured individually and averaged per unit area from micrographs that are obtained at various magnifications to account for differences in length and diameter.
Nanofibers can be used in either dry form or in the form of water slurry to make a porous fibrous sheet according to the present invention. Also, wood pulp can be added to the nanofibers described above. When using nanofibers in dry form, dry-laid methods known in the art can be applied to produce the porous fibrous sheets of this invention. These methods include, but are not limited to, air-laid technology and spunlace technology. When using nanofibers in the form of a slurry in water, wet-laid technology well known in the art for papers and wet-laid nonwovens can be used. Combinations of dry-laid and wet-laid methods can be used as well to make a porous fibrous sheet according to the present invention. The nanofibers used in this invention can be fibrillated or not.
An aqueous dispersion of nanofibers can be placed on a permeable screen and dewatered in a controlled way to form a high barrier layer. Binders used in papers may be added in the aqueous dispersion of the nanofibers to increase the strength of the resulting high barrier layer. Useful binders may be inorganic or organic. Typical binders are synthetic latex and are based on styrene-butadiene copolymers, polyvinyl acetate, and a variety of acrylic polymers. Other useful binders are disclosed in Koslow U.S. 2003/0177909. Similarly, wood pulp fibers may be blended with the nanofibers (with or without binders) and after removing the water to form a fibrous layer that has improved barrier versus paper of the same basis weight that does not contain nanofibers.
In one embodiment of the present invention, a porous fibrous paper-like sheet is prepared by wet-laying a furnish comprising nanofibers and wood pulp to form a porous paper-like sheet comprising between about 1 weight percent and 99 weight percent nanofibers and between about 99 and 1 weight percent of wood pulp, based on the total combined weight of wood pulp and nanofibers in the fibrous sheet. Fibrous sheets formed in this manner have the nanofibers and wood pulp fibers substantially uniformly distributed throughout the fibrous sheet.
In another embodiment of the present invention, a furnish comprising wood pulp can be wet laid to form a wood pulp layer followed by wet laying a furnish comprising nanofibers directly on the wet-laid wood pulp layer to form a layered porous paper-like sheet comprising between about 1 weight percent and 99 weight percent nanofibers and between about 99 and 1 weight percent of wood pulp, based on the total combined weight of wood pulp and nanofibers in the fibrous sheet. Additional layers can be deposited to form the desired number of layers. In a two-layer sheet, the nanofibers are concentrated on one outer surface of the sheet and the wood pulp fibers are concentrated on the other outer surface of the sheet. When more than two wet-laid layers are used, either a wood pulp layer or a nanofiber layer can form one or both of the outer surfaces of the sheet. Combinations can be made using layers of nanofibers, layers of wood pulp, and layers of nanofiber/wood pulp blends. A specific example would be a “sandwich-type” arrangement with two outer layers of wood pulp and an inner layer of a nanofiber/wood pulp blend, with the blend comprising between about 1 weight percent and 99 weight percent nanofibers and between about 99 and 1 weight percent of wood pulp, based on the total combined weight of wood pulp and nanofibers in the inner layer.
Alternately, a furnish comprising nanofibers can be wet laid on a pre-formed wood pulp-containing paper. Paper grades used in medical packaging vary in fiber density, porosity, various treatments, additives, and basis weight. Medical papers are bleached and highly refined and are made by the traditional wet laid process using virgin wood pulp. The preformed paper preferably has a basis weight of about 1.4 oz/yd 2 (49 g/m 2 ) to 2.9 oz/yd 2 (98 g/m 2 ). Kraft paper is a particular type of paper often used in medical packaging. It is made from kraft pulp and the method for making it involves cooking (digesting) wood chips in an alkaline solution for several hours during which time the chemicals attack the lignin in the wood. The dissolved lignin is later removed leaving behind the cellulose fibers. Unbleached kraft pulp is dark brown in color, so before it can be used in many papermaking applications it must undergo a series of bleaching processes.
The porous fibrous sheet according to the present invention can be additionally densified after forming to obtain optimum density to balance and optimize sheet porosity, barrier properties, and strength. The densification can be preformed by calendering the sheet in the nip of a hard (metal-metal) calender or a soft calender or by compression in different types of presses (platen press, double belt press, etc). The densification can be performed at room or at an elevated temperature.
The nanofibers are preferably deposited on the wet-laid wood pulp layer or pre-formed paper layer at between about 0.5 g/m 2 and 11.g/m 2 . Preferably, the nanofiber layer is the outer side of a medical package that is printed to identify the package. In this arrangement, possible microbial challenges are intercepted at the outer surface of the package and farther away from the sterilized contents. The opposite layer facing inside the package would be coated with a heat sealing formulation for heat sealing to the film.
The materials described above are especially suited for use in medical packaging. For example, a lidding component comprising the porous fibrous sheet of the present invention can be heat-sealed to a second component of thermoformed film after medical equipment or some other object to be sterilized is placed in a cavity formed from the thermoformed film. A heat seal layer can be extruded or coated onto the areas of the lidding that need to be sealed to the thermoformed film or can be extruded or coated onto the thermoformed film.
Test Methods
In the non-limiting examples that follow, the following test methods were employed to determine various reported characteristics and properties. ASTM refers to the American Society of Testing Materials. TAPPI refers to Technical Association of Pulp and Paper Industry.
Thickness and Basis Weight (Grammage) of papers were determined in accordance with ASTM D 645 and ASTM D 646 correspondingly.
Density (Apparent Density) of papers was determined in accordance with ASTM D 202.
Gurley Air Resistance (Gurley) for papers was determined by measuring air resistance in seconds per 100 milliliters of cylinder displacement for approximately 6.4 square centimeters circular area of a paper using a pressure differential of 1.22 kPa in accordance with TAPPI T 460.
Barrier Log Reduction Value (LRV) and Spore Penetration for papers is a measure of the bacterial barrier properties of a sheet and was determined in accordance with ASTM F 1608. Spore penetration was calculated as the percentage of spores that passed through a paper sample during the test. Higher LRV and lower spore penetration values correspond to higher bacterial barrier properties. LRV and percent spore penetration are calculated based on the specific number of colony forming units used in a specific test. Since this number varies by approximately 1×10 6 , the LRV and percent spore penetration will vary also.
Fiber Length and Length Distribution was determined with Fiber Quality Analyzer Serial Number LDA 96053 produced by OpTest Equipment Inc.
Fiber diameter was measured from scanning electron photomicrographs.
Canadian Standard Freeness (CSF) of the pulp and fibrillated fibers is a measure of the rate at which a dilute suspension of pulp may be drained and was determined in accordance with TAPPI Test Method T 227.
EXAMPLES
In the examples that follow, the fibrillated lyocell fibers were made by fibrillating 1.25 denier staple fibers having a length of 10 mm (available from Tencel, Inc.) in water using a Warner high-speed blender.
Examples 1-3
For Example 1, 4.0 g (based on dry weight) of a water slurry of fibrillated lyocell fiber with CSF of 40, arithmetic mean length of about 0.4 mm and weight weighted mean length of 2.6 mm (diameter of majority of nanofibers is in 200-400 nm range), was placed in a laboratory mixer (British pulp evaluation apparatus) with about 1600 g of water and agitated for 3 min.
The dispersion was poured, with 8 liters of water, into an approximately 21 cm×21 cm handsheet mold to form a wet-laid sheet. The sheet was placed between two pieces of blotting paper, hand couched with a rolling pin and dried in a handsheet dryer at 150° C. The final paper had a basis weight of 98.7 g/m 2 .
A second paper sample formed as described above for Example 1 was additionally passed through the nip of a metal-metal calender with a roll diameter of about 20 cm at a temperature of about 23° C. and linear pressure of about 2600 N/cm to obtain the paper sample of Example 2.
A third paper sample formed as described above for Example 1 was additionally compressed in a platen press at a temperature of about 23° C. and pressure of about 15 MPa for 1 min. By such treatment, the compressed paper sample of Example 3 was produced. Properties of the papers are shown in Table 1 below. Densification of the paper sample by calendering or compression results in an increase in the LRV (increased bacterial barrier) with a concomitant increase in Gurley air resistance (reduced air permeability).
Examples 4-5
For Example 4, 2.0 g (based on dry weight) of the same fibrillated lyocell fiber as in Example 1 and 2.0 g (based on dry weight) of Southern Bleached Hardwood Kraft pulp (from International Paper Company) refined to CSF of 104, were placed together in a laboratory mixer (British pulp evaluation apparatus) with about 1600 g of water and agitated for 3 min.
The solid materials in the slurry were: 50 weight percent fibrillated lyocell fiber and 50 weight percent wood pulp. A wet-laid paper was prepared and dried using the method described in Example 1. The final paper had a basis weight of 92.9 g/m 2 .
A second paper sample formed as described above for Example 4 was additionally calendered as described above for Example 2 to form the calendered paper of Example 5. Properties of the papers are shown in the Table 1 below.
Examples 6-7
Paper samples for Examples 6-7 were prepared and calendered as described above for Example 5, but with varying percentages of the two components (fibrillated lyocell fiber and wood pulp). The percentages of the two components of the paper compositions and the properties of the calendered papers are shown in Table 1 below.
Comparing the properties of the calendered papers of Examples 2 and 5-7, higher levels of lyocell nanofibers result in higher LRV and lower Gurley air resistance.
Examples 8-9
2.0 g (based on dry weight) of fibrillated lyocell fibers with a CSF of 150, arithmetic mean length of about 0.5 mm and weight weighted mean length of 3.8 mm (diameter of majority of nanofibers is in 200-400 nm range), and 2.0 g of the 104 CSF refined bleached hardwood pulp were placed in a laboratory mixer (British pulp evaluation apparatus) with about 1600 g of water and agitated for 3 min.
The dispersion was poured, with 8 liters of water, into an approximately 21 cm×21 cm handsheet mold to form a wet-laid sheet. The sheet was placed between two pieces of blotting paper, hand couched with a rolling pin and dried in a handsheet dryer at 150° C.
The dried paper was calendered as described above for Example 2 to obtain the calendered paper of Example 8.
A second paper sample was prepared as described for Example 8, except instead of calendering, the as-formed dried paper was compressed as described above for Example 3 to obtain the compressed paper of Example 9.
Properties of the papers are shown in Table 1 below.
Example 10
2.00 g (based on dry weight) of the same fibrillated lyocell fiber as in Example 1 and 2.00 g (based on dry weight) of bleached hardwood pulp refined to CSF of 254, were placed together in a laboratory mixer (British pulp evaluation apparatus) with about 1600 g of water and agitated for 3 min. The solid materials in the slurry were: 50 weight percent fibrillated lyocell fiber and 50 weight percent wood pulp.
The dispersion was poured, with 8 liters of water, into an approximately 21 cm×21 cm handsheet mold to form a wet-laid sheet. The sheet was placed between two pieces of blotting paper, hand couched with a rolling pin and dried in a handsheet dryer at 150° C.
The dried paper was calendered as described above for Example 2 to obtain the calendered paper of Example 10. Properties of the paper are shown in Table 1 below.
Example 11
2.00 g (based on dry weight) of the same fibrillated lyocell fiber as in Example 1 and 2.00 g (based on dry weight) of bleached hardwood pulp refined to CSF of 254 were placed together in a laboratory mixer (British pulp evaluation apparatus) with about 1600 g of water and agitated for 3 min. After that, 0.40 g (based on dry weight) of polyvinyl acetate dispersion Type DF 51/10 (available from AB Achema) was added and agitating was continued for an additional 3 min. The solid materials in the final slurry were: 45.45 weight percent fibrillated lyocell fiber, 45.45 weight percent wood pulp, and 9.1 weight percent polyvinyl acetate binder.
A wet-laid paper was prepared and dried using the method described in Example 1. The polyvinyl acetate binder was activated in the dryer. The dried paper was then calendered as described above for Example 2 to obtain the calendered paper of Example 11. Properties of the paper are shown in Table 1 below.
Example 12-13
2.00 g (based on dry weight) of the same fibrillated lyocell fiber as in Example 1 was placed in a laboratory mixer (British pulp evaluation apparatus) with totally of about 1600 g of water and agitated for 3 min.
The dispersion was poured, with 8 liters of water, into an approximately 21 cm×21 cm handsheet mold to form a wet-laid sheet.
2.00 g (based on dry weight) of bleached hardwood pulp refined to CSF of 104 was placed in a laboratory mixer (British pulp evaluation apparatus) with about 1600 g of water and agitated for 3 min.
The dispersion was poured, with 8 liters of water, into an approximately 21 cm×21 cm handsheet mold to form a second wet-laid sheet.
Both handsheets were placed together in the wet form face-to-face between two pieces of blotting paper, hand couched with a rolling pin and dried in a handsheet dryer at 150° C.
The dried 2-ply paper was calendered as described above for Example 2 to obtain the 2-ply calendered sheet of Example 12.
A second 2-ply paper was prepared as described for Example 12, except that instead of calendering the dried paper, it was compressed as described above for Example 3 to obtain the compressed 2-ply paper of
Example 13
Properties of the paper are shown in Table 1 below. Comparing Example 12 (calendered 50/50 nanofiber/wood pulp layered) to Example 5 (calendered 50/50 nanofiber/wood pulp blend), the LRV of the layered paper is slightly lower than that of the blend paper and both have LRV's that are significantly higher than conventional medical papers.
Examples 14-15
Electroblown continuous Nylon 6,6 nanofibers were prepared according to PCT International Publication Number WO 03/080905 to Kim et al. followed by placing with water in a Warner high-speed blender and agitating to reduce the fiber length and to disperse the fibers in water. The final nanofibers had an average diameter of about 500 nm (diameter range is from about 300 to about 700 nm), arithmetic mean length of about 0.19 mm and weight weighted mean length of about 0.66 mm. 2.00 g (based on dry weight) of the nanofibers and 2.00 g (based on dry weight) of bleached hardwood pulp refined to CSF of 254, were placed together in a laboratory mixer (British pulp evaluation apparatus) with about 1600 g of water and agitated for 3 min. The solid materials in the slurry were: 50 weight percent nylon nanofibers and 50 weight percent wood pulp.
A wet-laid paper was prepared and dried using the method described in Example 1. The dried paper was then calendered as described above for Example 2 to obtain the calendered paper of Example 14.
A second paper was prepared as described for Example 14 except that instead of calendering the dried paper, it was compressed as described above for Example 3 to obtain the compressed paper of Example 15.
Comparative Examples A and B
Comparative Examples A and B are commercially available wood-pulp based medical papers. Comparative Example A is 45# Impervon® medical paper and Comparative Example B is 60# Impervon® medical paper, both available from Kimberly-Clark Corporation.
Properties of the papers are shown in Table 1 below. All of the paper samples of the present invention have significantly higher LRV's than those of the commercial medical papers. By varying the percentage of nanofibers in the paper as well as the degree of densification, it is possible to achieve a wide range of Gurley Hill air resistance so that the paper properties can be tailored to meet the requirements of various sterilization processes used in the art.
TABLE 1
Paper Properties
Paper composition (wt. %)
Spore
Lyocell
Lyocell
Nylon 6,6
Wood
Wood
Basis
Thick-
Pene-
nanofibers
nanofibers
nanofibers
pulp
pulp
wt.
ness
Density
tration
Gurley
Example
40 CSF
150 CSF
500 nm
104 CSF
254 CSF
PVAc
Condition**
(g/m 2 )
(mm)
(g/cm3)
LRV
(%)
(sec)
1
100
98.7
0.416
0.24
5.9
0.0002
6.9
2
100
C
98.3
0.110
0.90
6.4
0.0000
49
3
100
P
97.9
0.221
0.44
6.4
0.0000
19
4
50
50
92.9
0.288
0.32
6.4
0.0000
17
5
50
50
C
94.4
0.106
0.90
6.0
0.0000
103
6
10
90
C
99.2
0.108
0.92
5.5
0.0001
174
7
1
99
C
95.2
0.100
0.95
5.5
0.0005
118
8
50
50
C
93.3
0.112
0.84
5.8
0.0001
51
9
50
50
P
89.9
0.201
0.45
6.2
0.0001
21
10
50
50
C
94.6
0.106
0.90
6.4
0.0000
62
11
45.45
45.45
9.1
C
96.2
0.112
0.86
5.9
0.0001
56
12*
50
50
C
93.3
0.102
0.91
5.7
0.0002
116
13*
50
50
P
93.5
0.206
0.45
5.8
0.0001
33
14
50
50
C
90.8
0.128
0.71
5.5
0.0004
29
15
50
50
P
90.8
0.207
0.44
6.1
0.0001
6.4
Comp A
MEDICAL PAPER
78.7
0.086
0.92
1.7
2.0159
86
Comp B
MEDICAL PAPER
99.4
0.124
0.80
3.4
0.0327
17
*2-ply paper
**Condition - C means calendered and P means compressed by a platen.
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Porous fibrous sheets are provided that are useful in end uses requiring microbial barrier properties such as medical packaging and medical gowns and drapes. The porous fibrous sheets may contain nanofibers and wood pulp.
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BACKGROUND OF THE INVENTION
An essential part of every building structure is an enclosing top surface, or roof. The basic function of all roofs is to provide a closing or sealing surface which prevents entry of wind, rain, snow, and cold into the building. Traditionally, roofs have been made of varied materials with correspondingly differing effectiveness. For sloped roofs, various types of overlaping shingles are generally employed with the down-slope overlap portion exceeding in width the exposed portion with vertical joints between shingle disposed above a monpenetrable shingle surface. Unfortunately, this requirement generally dictates the relatively thin thickness, and to some extent, the size and shape of the shingles and discourages the use of structurally strong construction arrangements. For example in the U.S. Pat. No. 2,264,546, to Oches, issued Dec. 2, 1941, a surface covering structure is disclosed which comprises a base member and a covering member each of which may be of diverse materials. However, the overlapping areas are small and consequently special provision, such as a backing strip, must be made to seal between adjacent members at the same level. In the Goss et al. patent, U.S. Pat. No. 2,297,353, issued Sept. 29, 1942, beveled siding is manufactured from scraps of material which are ordinarily wasted, but are effectively and securely united by a special tongue and groove arrangement whereby they compare favorably with long length lumber. In U.S. Pat. No. 2,519,950, issued Aug. 22, 1950, to Abraham there is disclosed an insulated clapboard siding comprising fiber board faced with mineral granules applied thereto. U.S. Pat. No. 2,624,920, issued Jan. 13, 1953, to Anderson relates to wooden shingles which are secured to a wooden backing and have interlocking tongue and groove connections. Two layers are employed, one layer being staggered relative to the other.
In a sloped roof, the connection of adjacent members becomes more critical due to the increasingly direct exposure to the effects of rain and snow with the consequent problems increasing as the slope decreases. Thus, despite structural advantages possible, it is seldom that vertical surface coverings as exemplified in the Oches patent are utilized for a sloping roof.
SUMMARY OF THE INVENTION
My invention is directed principally to the provision of a roofing shingle of substantially permanent character and relatively strong construction. The invention employs unique shingle members of metal such as copper, galvanized iron, aluminum or a combination of metals such as copper and lead. Such metal shingles are advantageously combined with a holding strip or anchor, the holding strip being made of wood, light weight concrete, insulation board plastic, styrofoam, etc.
The combination may, in the assembly of one form of my holding strip, be placed immediately upon the roof joists with the shingles superimposed thereover. Prevention of leakage between adjacent shingles at the same level is achieved by a biased overlap of the metal portion of the combination, the holding strip immediately under the biased overlap being solid.
Other objects, adaptabilities and capabilities of the invention will be understood by those skilled in the art from the description of the invention which follows, reference being had to the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a portion of a roof covered in accordance with my invention;
FIG. 2 is an enlarged section taken on line 2--2 of FIG. 1;
FIG. 3 is a perspective view of a holding strip;
FIG. 4 is a perspective view of a metal shingle;
FIG. 5 is a side view of a holding strip;
FIG. 6 is a plan illustration of a metal shingle with an intermediate portion removed and showing the trapezoidal configuration thereof;
FIG. 7 is a side view of a metal shingle installed on a modified holding strip and the entire finished product installed on a roof where the sheeting has been previously applied;
FIG. 8 is a side view similar to that of FIG. 7, of a metal shingle installed on a combination sheeting and holding strip, wherein the finished product is applied directly to the roof rafters without the use of separate sheeting;
FIG. 9 is a side view of a combination sheeting and holding strip and of the type shown in FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 of the drawings, a corner of a completed roof structure, generally designated by reference numeral 10, comprises a plurality of shingle body members 11 arranged in both horizontal and vertical overlapped relationships, as will be explained in greater detail hereafter. Each shingle body member is of generally trapezoidal configuration, i.e., the upper edge 14 and the lower edge 15 are parallel, whereas one of the vertical edges 16 is substantially perpendicular thereto and the other edge 17 is biased at substantially 45° relative to the upper edge, as is designated by reference numeral 18. The edge 17 is at an obtuse angle to the lower edge 15 of the same shingle body member. Also, lower edge 15 is bent at a substantially right angle to provide a ledge 19, and then further bent to provide a lip 20 extending substantially parallel to the face side of the shingle body member. Either end of shingle body member may be angled to the normal, but preferably not both ends.
The holding strip or anchor 21 is rectangular as seen in plan and is shown in enlarged detail in FIGS. 3 and 5. In crossection it is of generally wedge configuration. A recess 22 is formed at the thicker edge of the holding strip, providing a rib 34. Anchor 21 may be fashioned from wood, concrete, light weight concrete, insulation board, plastic, styrofoam, or the like. It will also be understood by those skilled in the art, that other well-known materials may be substituted.
In utilizing my invention, the conventional roof rafters 23, shown in FIG. 2, have applied thereto a covering sheeting 24. This covering sheeting spans a plurality of rafters to strengthen the roof and provide a base upon which to apply the shingle structure. Commencing with the eaves of the roof, a row or course of holding strips 21 are secured by nails 25 or the like to sheeting 24. The holding strips, it is to be noted, are butted end to end. It should also be noted that the nails penetrate only one course of holding strips. The next step is to cover the holding strips with a course of shingle body members. This is accomplished by disposing the rebent portion or lip 20 at a level below the recess 22 of the holding strip and sliding the shingle upwardly so that the rib 34 is disposed between the face and the lip 20 of the shingle body member. Ledge 19 is not forced tightly against the bottom of the rib 34 so as to allow a certain amount of air under rib 34. The next laterally adjacent shingle body member of the course overlaps the previous one to an extent that amply assures complete coverage of the roof surface, while at the same time permitting expansion and contraction of the metal during exposure to high and low temperatures as occasioned by weather changes. The overlapping portion includes the angularly biased edge 17 of shingle body member 11. This procedure is repeated with each successive shingle of the course. The shingles are secured adjacent their upper edges to the sheeting 24 by further nails 25a; it being noted that such nails do not penetrate the holding strip or anchor 21. Upon completion of one course, the next course upwardly is applied in the same manner, taking care that the overlapping edges of one course do not coincide with those of the previous course. At the lateral end of each course, any excess metal shingle is cut off and the edge bent downwardly to embrace the side of the holding strip. This procedure is repeated until the entire roof surface is completed up to the ridge. A roof made in this manner is substantially hurricane proof.
During a driving rain, water may be impelled with great force at an angle other than normal to the roof surface, with the result that some of the water is forced up the incline of the roof, finds its way under the seam or overlapping edges and falls by gravity to the channel formed by the face of shingle members 11, ledge 19 and lip 20. In conventional structures this water may remain in the channel for a prolonged period of time, with no means of escape, causing damage to the sheeting and structure below. I have found that by making the shingles of trapezoidal configuration, with the obtuse angle 33 at the lower portion, an extremely important advantage is obtained. The descending water driven into the overlapped biased portions is readily discharged because there is no other channel provided in that area of the shingle for the water to follow. Also, because the ledge 19 is not tightly against the bottom of rib 34, air may circulate freely therearound and drying will occur.
The construction shown in FIG. 7 is similar to that of FIG. 2 except that recesses 22 are not provided in anchors 21a and shingle body members 11a have a somewhat different cross-sectional configuration with the lip 20a parallel to the face of shingle member 11a and ledge 19a is disposed at an acute angle to lip 20a.
In FIGS. 8 and 9, the modified combination shingles and holding strip includes the same concept insofar as the trapezoidal configuration of the shingle is concerned. In this arrangement, however, the holding strip, in addition to serving as in the above-described modification, eliminates the need for a sheeting member to be applied to the rafters. The holding strip 27, although cross-sectionally tapered, is substantially thicker in its cross-sectional dimension than that of the modification illustrated in FIGS. 2 and 5. Further, the lower edge, in addition to having a rib 28, is provided with a groove 29. The upper edge includes a tongue 30. It will be readily observed that when successive courses of these holding strips are assembled, the tongue of the lower strip mates with the groove of the upper. Nails 31 fasten the holding strips and shingles in the same manner as above described. In addition, nails 31a fasten the shingles to the holding strip.
In either modification, the length of the holding strip or anchor may vary in accordance with manufacturing requirements and other desired parameters. Also, the specific width of the metal shingle and holding strip, as well as the sizes of the tongues, grooves, ribs, channels and lips may be varied. The nails utilized are preferably of the type provided with spiral knulings or ribs, commonly known as "screw-type" nails, to prevent them from backing out.
The metal shingle body member and holding strip arrangement above described may be applied, if desired, directly over a conventional shingle roof.
Although the preferred embodiments of the invention are described above, it is to be understood that the inventive concepts are capable of other adaptations and modifications within the scope of the following claims.
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A metal roofing shingle having a main body portion of a generally trapezoidal configuration. A holding strip is utilized for supporting and backing the shingle, when applied to a roof. The entire structure is waterproof, easy to install and extremely durable. The trapezoidal shape of the shingle body provides a unique arrangement whereby moisture which may be driven thereunder by rain storms is readily drained.
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[0001] This application claims priority from Australian Application Serial No. 2009901291 filed on Mar. 25, 2009.
TECHNICAL FIELD
[0002] The present invention relates to product packaging and particularly relates to packaging of product samples and a method of providing those samples.
BACKGROUND TO THE INVENTION
[0003] In retail outlets, an ever increasing number of brands compete for recognition and adoption by customers. As the number of available brands grows, the customer is faced with a wider and wider choice and it becomes still harder for brands to stand out in a retail and consumer-facing environment. For instance, in a retail wine store there may be up to 8000 different wines for sale derived from a wide range of producers, and each producer may promote a range of brands. It is becoming increasingly difficult for one wine brand to stand out from the rest. Further, it has been found that wine consumers will tend to choose a brand that they are already familiar with. One reason for this is that a typical bottle of wine contains the volume of about six glasses of wine. If a consumer buys a bottle of a new variety of wine and then discovers that they do not like the taste of the wine, then almost the entire bottle is unwanted by the consumer and the entire cost of the bottle of wine is seen by the consumer as a waste of money.
SUMMARY OF THE INVENTION
[0004] In a first aspect the present invention provides a sample pack including: a number of product packages; and a premium package.
[0005] The product packages may be drink packages, and the premium package may include one or more items that relate to the drink packages.
[0006] The premium package may include a drink pourer for dispensing drink from the drink packages.
[0007] The premium package may include a drinking vessel for use in consuming the drinks in the drink packages.
[0008] The drink packages may be wine packages.
[0009] The drink packages may be approximately cube shaped.
[0010] The sample pack may include an outer packaging.
[0011] The outer packaging may be of the form of a standard sized wine bottle box.
[0012] The contents of the premium package may not be determinable until the sample pack is opened.
[0013] In a second aspect the present invention provides a range of sample packs according to the first aspect of the invention which include various different premium packages.
[0014] In a third aspect the present invention provides a method of providing product samples including the steps of: receiving product derived from a manufacturer; packaging the product into a number of sample packs according to the first or second aspects of the invention; and introducing the sample packs into product distribution channels alongside products derived from the manufacturer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
[0016] FIG. 1 is a perspective view of an embodiment of a sample pack;
[0017] FIG. 2 shows the wine packages found in the sample pack of FIG. 1 ;
[0018] FIG. 2B shows one of the wine packages of FIG. 1 in knife-line view; and
[0019] FIGS. 3 to 8 show examples of premium items that can be found in the sample pack of FIG. 1 .
DETAILED DESCRIPTION
[0020] Referring to FIG. 1 , a sample pack 10 is shown including an outer sleeve 12 which has the same outer dimensions as a standard wine bottle box. The pack 10 includes three product packages in the form of cube-shaped wine packages 14 . The three wine packages 14 are visible through an elongate window 16 provided on one side of sleeve 12 . The pack 10 further includes a premium item which is stored in the upper region 18 of the pack and is not visible through window 16 . The outer sleeve is formed from a glossy printed cardboard blank and constructed into a box in a known manner. The wine packages 14 are packed in carton packages such as those sold under the names Tetra Prisma Aseptic, or Tetra Brik Aseptic produced by Tetra Pak International. The wine packages have a volume of approximately between 150 ml to 250 ml.
[0021] Referring to FIG. 2 , the three wine packages 14 are shown in more detail. In this case the packages 14 each include various styles of wine sold under a brand of a wine producer. The packages also display the brand and/or the name of the wine producer. The styles in this example are semillon sauvignon blanc 14 A, moscato 14 B and merlot 14 C. Each package 14 includes a membrane portion 20 which can be pierced to gain access to the wine to pour out the wine inside the package. Also provided is a piercable vent hole 21 which may be pierced to allow air to enter the package to assist in pouring.
[0022] Referring to FIG. 2B , an example of one of the packages 14 of FIG. 1 is shown laid out in knife-line view so that all six faces of the package can be seen. The package 14 further includes identifying data 22 including sample number, date, region and winemaker.
[0023] Referring to FIG. 3 , one example of a premium package is shown in the form of wine glass 24 . The various wines found in packages 14 can be properly enjoyed in a glass, as by using the glass the customer can see the colour of the wine, and smell the bouquet of the wine. The customer may be motivated to subsequently purchase additional sample packs to collect a set of glasses 24 .
[0024] Referring to FIGS. 4A , 4 B the premium package may include a wine pourer 26 . The wine pourer may include a protective cap 28 to cover the sharp piercing point 30 when not in use. Referring to FIG. 5 , operation of pourer 26 is illustrated. Piercing point 30 is pushed through membrane portion 20 of one of packs 14 to enable pouring of the wine contained therein. The pourer 26 may be provided inside glass 24 in the package.
[0025] Referring to FIG. 6 , the premium package may include one or more wine charms 32 for use in attaching to the stem of a wine glass or wine related premiums. The charms are of different colours and allow a number of guests at a party or gathering to identify their own wine glass by remembering the colour of their wine charm. An alternative embodiment of wine charms 34 are shown in FIG. 7 . Referring to FIG. 8 , the premium package may include a finger food cocktail tray 36 or other novelty item that can be used in conjunction with wine.
[0026] The various premium items enhance enjoyment of the wine sample packs. Further, elements of the premium package may vary between sample packs. The premium package is not visible to the customer at the time of purchase, therefore there is an element of mystery and surprise for the customer to see what item is in the premium package. Customers can collect the various items thereby encouraging repeat purchases.
[0027] It is intended that sample packs 10 be sold at a price that is similar to, or less than, a bottle of similar wine. By purchasing a sample pack 10 , a consumer can “try before they buy” and try out three wines for the price of buying one bottle of wine. The consumer may then decide whether they like any or all of the wines, and may later purchase a full bottle of one or more of the wines on their next visit to the wine store.
[0028] By producing sleeve 12 to be the size of a standard wine bottle box, the sample packs 10 can be easily integrated into existing wine distribution channels with existing shelving and handling facilities sized to suit existing wine boxes.
[0029] To produce the sample packs, a wine producer arranges delivery of large bulk containers of their wine to a packaging plant. The wine is packaged into the sample packs, and the sample packs are delivered back into to the distribution network used by the wine manufacturer. Thus, the sample packs may then be distributed and offered for sale alongside the regular full size wine products.
[0030] Although the invention has been described above with reference to packaging of wine samples, it can be used in relation to other types of products. For instance, the sample packs can contain cosmetics, cooking oils, sauces, condiments, soups and the like. Similarly, the premium packages offered alongside the samples can vary to be relevant to the sample products. For instance, a sample pack containing condiments may include serving utensils or small serving dishes or the like.
[0031] The invention has been described with reference to a sample pack containing three approximately cube sized packages. In other embodiments, the sample pack may contain a lesser or greater number of sample packs, which may not be cube shaped.
[0032] In the embodiment described above, the outer packaging included a window through which the samples can be seen. In other embodiments there is no window, and information relating to the samples may be printed on the outside of the outer sleeve.
[0033] In the embodiment described above, the sample packs had a volume of approximately 200 ml or so. In other embodiments the sample packs may be of different volumes, and may contain equivalent or greater volumes and measures for food stuffs.
[0034] It can be seen that embodiments of the invention have at least one of the following advantages:
Consumer need not buy an entire bottle of wine that they are unfamiliar with, only to find that it is not to their taste. Consumers need not consume an entire bottle of wine in one sitting. Wine producers product stands out in a store against a backdrop of numerous traditional wine bottles. An element of mystery and surprise arouses interest in the purchaser. Purchaser may collect premium items.
[0040] Any reference to prior art contained herein is not to be taken as an admission that the information is common general knowledge, unless otherwise indicated.
[0041] Finally, it is to be appreciated that various alterations or additions may be made to the parts previously described without departing from the spirit or ambit of the present invention.
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A sample pack and method of providing product samples are described. The sample packs include a number of product packages; and a premium package. The method includes the steps of receiving product derived from a manufacturer; packaging the product into a number of sample packs; and introducing the sample packs into product distribution channels alongside products derived from the manufacturer.
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FIELD OF THE INVENTION
The present invention concerns the field of molecular genetics and medicine. Particularly, it concerns a gene encoding a protein that is a kinase and is involved in cell cycle regulation and the repair of damaged genomic DNA in mammalian cells. The gene and protein, termed herein, respectively hsREC2 and hsRec2, is in the same supergene family as the mammalian protein having homologous pairing and strand transfer activities, RAD51 and was isolated because of its homology to the homologous pairing and strand transfer protein of Ustilago maydis. Due to this relationship the same gene and protein is termed elsewhere RAD51B and Rad51B.
BACKGROUND OF THE INVENTION
2.1 The Structure and Function of hsREC2
During the life of every organism the DNA of its cells is constantly subjected to chemical and physical events that cause alterations in its structure, i.e., potential mutations. These potential mutations are recognized by DNA repair enzymes found in the cell because of the mismatch between the strands of the DNA. To prevent the deleterious effects that would occur if these potential mutations became fixed, all organisms have a variety of mechanisms to repair DNA mismatches. In addition, higher animals have evolved mechanisms whereby cells having highly damaged DNA, undergo a process of programmed death (“apoptosis”).
The association between defects in the DNA mismatch repair and apoptosis inducing pathways and the development, progression and response to treatment of oncologic disease is widely recognized, if incompletely understood, by medical scientists. Chung, D. C. & Rustgi, A. K., 1995, Gastroenterology 109:1685-99; Lowe, S. W., et al., 1994, Science 266:807-10. Therefore, there is a continuing need to identify and clone the genes that encode proteins involved in DNA repair and DNA mismatch monitoring.
Studies with bacteria, fungi and yeast have identified three genetically defined groups of genes involved in mismatch repair processes. The groups are termed, respectively, the excision repair group, the error prone repair group and the recombination repair group. Mutants in a gene of each group result in a characteristic phenotype. Mutants in the recombination repair group in yeast result in a phenotype having extreme sensitivity to ionizing radiation, a sporulation deficiency, and decreased or absent mitotic recombination. Petes, T. D., et al., 1991, in Broach, J. R., et al., eds., The Molecular Biology of the Yeast Saccharomyces, pp. 407-522 (Cold Spring Harbor Press, 1991).
Several phylogenetically related genes have been identified in the recombination repair group: recA, in E. Coli, Radding, C. M., 1989, Biochim. Biophys. Acta 1008:131-145; RAD51 in S. cerevisiae, Shinohara, A., 1992, Cell 69:457-470, Aboussekhra, A. R., et al., 1992, Mol. Cell. Biol. 12:3224-3234, Basile, G., et al., 1992, Mol. Cell. Biol. 12:3235-3246; RAD57 in S. cerevisiae, Gene 105:139-140; REC2 in U. maydis, Bauchwitz, R., & Holloman, W. K., 1990, Gene 96:285-288, Rubin, B. P., et al., 1994, Mol. Cell. Biol. 14:6287-6296. A third S. cerevisiae gene DMC1, is related to recA, although mutants of DMC1 show defects in cell-cycle progression, recombination and meiosis, but not in recombination repair.
The phenotype of REC2 defective U. maydis mutants is characterized by extreme sensitivity to ionizing radiation, defective mitotic recombination and interplasmid recombination, and an inability to complete meiosis. Holliday, R., 1967, Mutational Research 4:275-288. UmREC2, the REC2 gene product of U. maydis, has been extensively studied. It is a 781 amino acid ATPase that, in the presence of ATP, catalyzes the pairing of homologous DNA strands in a wide variety of circumstances, e.g., UmREC2 catalyzes the formation of duplex DNA from denatured strands, strand exchange between duplex and single stranded homologous DNA and the formation of a nuclease resistant complex between identical strands. Kmiec, E. B., et al., 1994, Mol. Cell. Biol. 14:7163-7172. UmREC2 is unique in that it is the only eukaryotic ATPase that forms homolog pairs, an activity it shares with the E. coli enzyme recA.
U.S. patent application Ser. No. 08/373,134, filed Jan. 17, 1995, by W. K. Holloman and E. B. Kmiec discloses REC2 from U. maydis, methods of producing recombinant UmREC2 and methods of its use. Prior to the date of the present invention a fragment of human REC2 cDNA was available from the IMAGE consortium, Lawrence Livermore National Laboratories, as plasmid p153195. Approximately 400 bp of the sequence of p153195 had been made publicly available on dbEST database.
The scientific publication entitled: Isolation of Human and Mouse Genes Based on Homology to REC2, July 1997, Proc. Natl. Acad. Sci. 94, 7417-7422 by Michael C. Rice et al., discloses the sequences of murine and human Rec2, of the human REC2 cDNA, and discloses that irradiation increases the level of hsREC2 transcripts in primary human foreskin fibroblasts. The scientific publication Albala et al., December 1997, Genomics 46, 476-479 also discloses the sequence of the same protein and cDNA which it terms RAD51 B. A sequence that is identical to hsREC2 except for the C-terminal 14 nucleotides of the coding sequence and the 3′-untranslated sequence was published by Cartwright R., et al., 1998, Nucleic Acids Research 26, 1653-1659 and termed hsR51h2. It is believed that hsREC2 and hsR51h2 represent alternative processing of the same primary transcript. The parent application of this application was published as WO 98/11214 on Mar. 19,1998.
The structure of hsREC2 is also disclosed in application Ser. No. 60/025,929, filed Sep. 11, 1996, application Ser. No. 08/927,165, filed Sep. 11, 1997, and patent publication WO 98/11214, published Mar. 19, 1998.
2.2 Cell Cycle Regulation
The eukaryotic cell cycle consists of four stages, G 1 , S (synthesis), G 2 , and M (mitosis). The underlying biochemical events that determine the stage of the cell and the rate of progression to the next stage is a series of kinases, e.g., cdk2, cdc2, which are regulated and activated by labile proteins that bind them, termed cyclins, e.g., cyclin D, cyclin E, Cyclin A . The activated complex in turn phosphorylates other proteins which activates the enzymes that are appropriate for each given stage of the cycle. Reviewed, Morgan, D. O., 1997, Ann. Rev. Cell. Dev. Biol. 15, 261-291; Clurman, B. E., & Roberts, J. M., 1998, in The Genetic Basis of Human Cancer, pp. 173-191 (ed. by Vogelstein, B., & Kinzer K. W., McGraw Hill, N.Y.) (hereafter Vogelstein)
The cell cycle contains a check point in G 1 . Under certain conditions, e.g., chromosomal damage or mitogen deprivation, a normal cell will not progress beyond the check point. Rb and p53 are proteins involved in the G 1 check point related to mitogen deprivation and chromosomal damage, respectively. Inactivating mutations in either of these proteins results, in concert with other mutations, in a growth transformed, i.e., malignant, cell. The introduction of a copy of the normal p53 or Rb gene suppresses the transformed phenotype. Accordingly genes, such as p53 or Rb, whose absence is associated with transformation are termed “tumor suppressor” genes. A frequent cause of familial neoplastic syndromes is the inheritance of a defective copy of a tumor suppressor gene. Reviewed Fearson, E. R., in Vogelstein pp. 229-236.
The level of p53 increases in response to chromosomal damage, however, the mechanism which mediates this response is unknown. It is known that p53 can be phosphorylated by a variety of kinases and that such phosphorylation may stabilize the p53 protein. Reviewed Agarwal, M. L., et al., Jan. 2, 1998, J. Biol. Chem. 273, 1-4.
SUMMARY OF THE INVENTION
The present invention is based on the unexpected discovery that hsRec2 is a serine kinase that phosphorylates several proteins that control the cell cycle, particularly cyclin E and p53. The invention permits the phosphorylation of the cell cycle control proteins at sites that are physiologically elevant. In addition, the discovery of the enzyme activity of Rec2 permits the construction of assays for the discovery of compounds that are specific antiagonists and agonists of Rec2, which compounds have a pharmacological activity.
BRIEF DESCRIPTION OF THE FIGURES
FIGS. 1 A- 1 D. FIGS. 1A and 1B show the derived amino acid sequence of hsREC2 (SEQ ID NO:1) and
FIGS. 1C and 1D show the nucleic acid sequences of the hsREC2 cDNA coding strand (SEQ ID NO:2).
FIGS. 1E and 1F show the derived amino acid sequence of mu REC2 (SEQ ID NO:3) and
FIG. 1G shows the nucleic acid sequences of the muREC2 cDNA coding strand (SEQ ID NO:4).
FIGS. 2 A- 2 D. FIG. 2A is an annotated amino acid sequence of hsREC2. Specifically noted are the nuclear localization sequence (“NLS”), A Box and B Box motif sequences, DNA binding sequence and a src-type phosphorylation site (“P”).
FIG. 2B is a cartoon of the annotated sequence, showing in particular that the region 80-200 is most closely related to recA.
FIGS. 2C and 3D show the sequence homology between hsREC2 and Ustilago maydis REC2. The region of greatest similarity, 43% homology, is in bold.
FIGS. 3 A- 3 B. A. The incorporation of 32 P-ATP into myelin basic protein (0.25 μM) as a function of time, concentration of Rec2 was 1 μg/30-40 μl. B. The incorporation of 32P-ATP into kemptide (LRRASLG, SEQ ID No: 5) during a 60 min. reaction as a function of kemptide concentration.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, genes are all capitlized, e.g., hsREC2, while the corresponding protein is in initial capitalization, e.g., hsRec2.
The activity of hsREC2 was determined using an N-terminal hexahistadyl containing derivative that was produced in baculovirus. Confirming results were obtained with baculovirus produced glutathione-Stransferase conjugated hsREC2 and with thioredoxin-conjugated hsREC2 produced in E. coli . These confirming results tend to exclude that the kinase activity resulted from the co-purification of an endogenous baculovirus kinase on the Ni-NTA resin. To further exclude the possibility of purification artifacts the Ni-NTA purified hexahistadyl-hsREC2 was further purified by preparative SDS-PAGE. Only the fractions containing hsREC2 by silver stain were found to contain kinase activity.
The sequence of muRec2 and hsRec2 differ at only 56 of the 350 amino acids. The invention can be practiced using either muRec2 or hsRec2 or a protein that consists of a mixture of amino acids, i.e., at some positions the amino acid is that of muRec2 and at others the amino acid is that of hsRec2, hereafter a chimeric hs/muRec2. In addition, the mutein having a substitution for the tyrosine at position 163 can be used to practice the invention, e.g., Tyr→Ala . Thus, the invention can be further practiced using a chimeric hs/muREC2 ala163 . In one embodiment the substitution can be any aliphatic amino acid. In an alternative embodiment the substitution can be any amino acid other than cysteine or proline. The term “Rec2 kinase” is used herein to denote the genus consisting of hsRec2, muRec2 and all chimeric hs/muRec2 proteins and the Tyr 163 substituted derivatives of each. The term artificial Rec2 kinase is a Rec2 kinase that is not also a mammalian Rec2. The term mammalian Rec2 is used herein to denote the genus of proteins consisting of the mammalian homologs of hsRec2 and of muRec2.
The invention can further be practiced using a fusion protein, which consists of a protein having a sequence that comprises that of a Rec2 kinase or a mammalian Rec2 that is fused to a second sequence which is a protein or peptide that can be used to purify the resultant fusion protein.
The naturally occurring hsRec2 and muRec2 are found as phosphoproteins, the phosphorylation of which is not essential to the activity of the proteins as a kinase. In, the invention the terms Rec2 kinase and mammalian Rec2 encompass both the phosphorylated and non-phosphorylated forms of the proteins.
5.1 Cell Cycle Regulation
An expression vector comprising hsREC2 operably linked to the CMV immediate early promoter was constructed and transfected into CHO cells. A mutein was constructed in which tyrosine-163, a phosphorylatable tyrosine in an src site (phe-pro-arg-tyr) (amino acids 8-11 of SEQ ID No. 8) was replaced by alanine (hsREC2 ala163 ). Sham (neo r ) transfected, hsREC2 transfected and hsREC2 ala163 transfected CHO cells were synchronized by serum starvation, released, and the DNA content was assayed by quantitative fluorescent flow cytometry at various time points. The hsREC2 transfected cells showed delayed onset of S phase. Thus, at 14 hours post release 75% of the hsREC2 transfected cells were in G 1 compared to 36% of the controls.
Over expression of hsREC2 but not hsREC2 ala163 sensitizes the cell to UV radiation. CHO cells were irradiated with UV at 15 J/m 2 . Again the cells were analyzed by quantitative fluorescent flow cytometry The hsREC2 cells showed extensive apoptosis compared to the controls at 24, 48 and 72 hours post irradiation.
5.2 Kinase Activity
The kinase activity of hsREC2 can be shown on a variety of substrates. Artifactual substrates such as myelin basic protein, which is a known substrate for protein kinase C and protein kinase A are phosphorylated by hsREC2. The kemptide (leu-arg-arg-ala-ser-leu-gly), which is also a known substrate of ser/thr kinases can be phosphorylated. In addition the following recombinantly produced proteins are phosphorylated by hsREC2: p53, cyclin B1 and cyclin E. The heterodimers of cyclin B1/cdc2 and cyclin E/cdk2 are also phosphorylated by hsREC2. The interpretation of these experiments is complicated by the fact that cyclin E/cdk2 autophosphorylates and that cyclin B1/cdc2 but not cyclin E/cdk2 phosphorylates hsREC2 itself. In contrast to the cyclinB1/cdc2 complex, hsRec2 is not an autophosphorylase.
Although expression of hsREC2ala 63 in a cell has no effect on the cell cycle, the hsREC2 ala163 mutein has full kinase activity.
Compounds having pharmacological activity with respect to mREC2 can be identified by assaying the kinase activity of an mREC2, and particularly hsREC2, in the presence of candidate agonists or antagonists. The particular preferred substrates are cyclin E and p53.
5.3 hsREC2 Association With Other Proteins
An S 35 -radiolabeled preparation of hsREC2 was made by coupled transcription translation in a recticulocyte lysate system. The preparation was mixed with an extract from HCT116 cells. In separate reactions monoclonal antibodies to various cell proteins were added and the antibody bound material isolated with Protein A Sepharose. The bound material was then analyzed by SDS-PAGE, and autoradiographed. The immunoprecipitate contained hsREC2 when anti-p53, anti-PCNA and anti-cdc2 monoclonals were used. No hsREC2 was precipitated when anti-cdc4 or anti-cdk4 monoclonals were employed.
5.4 An hsREC2 Agonist or Antagonist Has a Pharmacologic Activity
The activities of hsREC2 indicate that the modulation of its activity can sensitize or desensitize a cell to enter apoptosis as a result of incurring genetic damage, as for example by UV radiation, and can also protect or deprotect a cell from DNA damage by extending or shortening the G 1 and S periods. Agonist and antagonists of hsREC2 are compounds having activities of the type that medical practitioners desire. The discovery of compounds that are hsREC2 agonists or antagonists will be important in pharmaceutical science.
In one embodiment, the invention is a method of determining whether a given compound has such a pharmacological activity by measuring the effects of the compound on the kinase activity of hsREC2. In specific embodiments, the invention is a method wherein the relative effects of the compound on hsREC2 and on a second kinase are assessed. For example, a compound that is an agonist of hsREC2, but has little or no effect on cyclin D/cdk4 and cyclin E/cdk2 would cause cells to arrest in G 1 and undergo apoptosis in response to genetic damage. In particular embodiments, the kinase assay is done with a substrate that is selected from the group consisting of p53, cdc2, cdk2 or cyclin E. Alternatively, the substrate can be a model substrate such as myelin basic protein or kemptide (leu-arg-arg-ala-ser-leu-gly).
EXAMPLES
6.1 The production of recombinant hsREC2 protein by baculovirus infection of Autographica californica
To facilitate the construction of an hsREC2 expression vector, restriction sites for Xhol and Kpnl were appended by PCR amplification to a the hsREC2 cDNA. The hsREC2 cDNA starting at nt 71 was amplified using the forward primer 5′-GAG CTCGAG GGTACC C ATG GGT AGC AAG AAA C-3′ (SEQ ID NO:6), which placed the Xhol and Kpnl sites (underlined) 5′ of the start codon. The recombinant molecule containing the entire coding sequence of hsREC2 cDNA, can be removed using either Xhol or Kpnl and the unique Xbal site located between nt 1270 and 1280 of SEQ ID NO:2.
A vector, pBacGSTSV, for the expression of HsREC2 in baculovirus infected Spodoptera frugiperda (Sf-9) insect cells (ATCC cell line No. CRL1711, Rockville Md.), was obtained from Dr. Zailin Yu (Baculovirus Expression Laboratory, Thomas Jefferson University). The vector pVLGS was constructed by the insertion of a fragment encoding a Schistosoma japonicum glutathione S-transferase polypeptide and a thrombin cleavage site from pGEX-2T (described in Smith & Johnson, GENE 67:31 (1988)), which is hereby incorporated by reference, into the vector pVL1393. A polyA termination signal sequence was inserted into pVLGS to yield pBacGSTSV. A plasmid containing the 1.2 Kb hsREC2 fragment was cut with Kpnl, the 3′ unpaired ends removed with T4 polymerase and the product cut with Xbal. The resultant fragment was inserted into a Smal, Xbal cut pBacGSTSV vector to yield pGST/hsREC2.
Recombinant virus containing the insert from pGST/hsREC2 were isolated in the usual way and Sf-9 cells were infected. Sf-9 cells are grown in SF90011 SFM (Gibco/BRL Cat # 10902) or TNM-FH (Gibco/BRL Cat # 11605-011) plus 10% FBS. After between 3-5 days of culture the infected cells are collected, washed in Ca ++ and Mg ++ free PBS and sonicated in 5 ml of PBS plus proteinase inhibitors (ICN Cat # 158837), 1% NP-40, 250 mM NaCl per 5×10 7 cells. The lysate is cleared by centrifugation at 30,000× g for 20 minutes. The supernatant is then applied to 0.5 ml of glutathione-agarose resin (Sigma Chem. Co. Cat # G4510) per 5×10 7 cells. The resin is washed in a buffer of 50 mM Tris-HCl, pH 8.0, 150 mM NaCl and 2.5 mM CaCl 2 , and the hsREC2 released by treatment with thrombin (Sigma Chem. Co. Cat # T7513) for 2 hours at 23° C. in the same buffer. For certain experiments the thrombin is removed by the technique of Thompson and Davie, 1971, Biochim Biophys Acta 250:210, using an aminocaproyl-p-chlorobenzylmide affinity column (Sigma Chem. Co. Cat # A9527).
Alternatively, the full length hsREC2 cDNA was cloned into the expression vector, pAcHisA, for overexpression in a baculovirus system and purification utilizing a 6 histidine tag. For cloning, the hsREC2 expression cassette was cut with Kpnl, the 3′ protruding termini were removed with T4 polymerase, and the DNA was then digested with Xbal. The resulting fragment was ligated to pAcHisA using the Smal and Xbal sites. Recombinant virus containing hsREC2 was purified and insect cells were infected by Dr. Z. Yu in the Baculovirus expression laboratory of the Kimmel Cancer Institute. Insect cell pellets from 2 liters of culture were suspended in 60 ml of 10 mM TrisCl, pH 7.5, 130 mM NaCl, 2% TX100, 2 μg/ml leupeptin and aprotinin and 1 μg/ml pepstatin and sonicated on ice 4 times for 5 seconds each using a microtip at a 20% pulse (Branson sonifier 450). Debris was removed by centrifuging at 30,000× g for 20 minutes. The clarified supernatant was divided between two 50 ml culture tubes and 1 ml of Ni-NTA agarose added to each tube for 1 hour with rocking at 4° C. The unbound fraction was separated from the resin by a brief centrifugation and the resin was washed with 10 ml of 100 mM imidazole for 10 minutes on a rocker and centrifuged at 2000 rpm for 5 minutes. After a second 10 minute wash with 500 mM imidazole the slurry was transferred to a column and the effluent discarded. The purified his-hsRec2 was eluted with 1M imidazole, pH 7.0 (imidazole on column for 10 minutes before collection of eluate), and dialyzed overnight against 50 mM TrisCl, pH 7.4, 50 mM NaCl, 10% glycerol. For simplicity, this protein will be referred to as hsRec2 instead of hishsRec2.
6.2 The Bacterial Production of recombinant hsREC2 protein
The hsREC2 cDNA coding region was excised from the previously used mammalian expression vector pcDNA3 G8 by cleavage with Xbal, removal of 5′ protruding termini with T4 polymerase, followed by cleavage with Kpnl. The resulting fragment was ligated into the Kpnl and blunted HindIII sites of a bacterial expression vector pBAD/HisC (Invitrogen, Corp., USA). The constructed expression vector with hREC2 cloned in frame with a hexahistidine tag was electrotransformed into LMG 194 bacteria (Invitrogen, Corp., USA) for expression. A 500 ml LB ampicillin culture was inoculated by a single colony and grown at 37° into log phase. The culture was induced by 0.02% arabinose for 4 hours and harvested by centrifuging at 8,000× g. The pellet was resuspended and lysed by 1 mg/ml lysozyme and sonication in 5 volumes of 50 mM NaH 2 PO 4 , 300 mM NaCl, 1% TX100, 2 μg/ml leupeptin and aprotinin and 1 μg/ml pepstatin, 0.1 mg/ml DNase I, 10 mM βME and 20 mM imidazole at 0° C. The lysate was clarified by centrifugation at 10,000× g for 30 minutes then added to a sealed column containing 1 ml activated Ni+NTA agarose resin and rocked at 4 for 1 hour. The column was then opened and washed by gravity with 20 volumes of 50 mM NaH 2 PO 4 , 300 mM NaCl, 1% TX100, 50 mM imidazole at 4°. The bound protein was then eluted in 3 volumes of the above wash buffer with 500 mM imidazole and collected in 1 ml fractions. The purified His-HsRec2 was dialyzed over night against 50 mM Tris, 50 mM NaCl, 10% glycerol and stored at −80°.
6.3 Detection of hsREC2 Kinase
Phosphokinase filter assays. Substrates were either kemptide or myelin basic protein and approximately 1 μg of hishsRec2 was added as the phosphokinase. For both assays, the buffer contained 50 mM TrisCl, pH 7.5, 10 mM MgCl 2 , 1 mM DTT. The second substrate, 32 P-ATP was constant at 50 μM with a specific activity of 1972 cpm/pmole (kemptide) and 2980 cpm/pmole (MBP). 32 P-ATP was added to initiate the reaction which was carried out at 30° C. for the indicated time. At the end of the reaction, 20 μl was spotted on phosphocellulose discs, washed twice with 10 ml per disc in 1% phosphoric acid and twice in distilled water. Filters were counted in a Wallac Scintillation counter. Substrate without hsRec2 added was used as a control and counts were subtracted to obtain a zero point.
Myelin basic protein (0.25 μM) was phosphorylated for between 0 and 25 minutes at the above conditions. Phosphate incorporation was linear with time and reached 1.2 pmole at 25 minutes. Kemptide from 0 to 0.15 mM was phosphorylated for 60 minutes. The rate of phosphate incorporation was linear with substrate concentration up to 0.06 mM, where a rate of 0.09 pmoles/minute was observed.
Two different hsRec2 conjugates, GST-hsRec2 and thioredoxin-hsRec2, also exhibited phosphokinase activity. Further evidence that this activity was not a contaminant, was obtained by immunoprecipitating hsREC2 using hybridoma supernatants, followed by assay for phosphokinase activity using p53 as a substrate as described below. These experiment confirmed that the kinase activity was precipitable by anti-hsREC2 monoclonal antibodies.
Two substrates that were not phosphorylated by hsRec2, were a tyrosine kinase substrate peptide containing one tyrosine, derived from the sequence surrounding the phosphorylation site in pp60 src (RRLIEDAEYAARG) (SEQ ID No. 7), and an hsRec2 peptide, residues 153-172 (VEIAESRFPRYFNTEEKLLL) (SEQ ID No. 8).
p53 phosphorylation. Human recombinant p53 (0.5 μg, Pharmingen, San Diego, Calif.) was incubated with or without hsRec2 in 50 mM TrisCl, pH 7.4, 10 mM MgCl 2 , and 1 mM DTT at 30° C. The reaction was initiated by the addition of 32 P-ATP (25 μM ATP, 40 cpm/femtomole). At the end of each time point an equal volume of 2× loading buffer (5) was added and tubes were placed on ice until all tubes were collected. Samples were then heated at 100° C. for 10 minutes and 13 μl were run on Ready Gels (Bio-Rad Laboratories, Hercules, Calif.), and transferred to nitrocellulose overnight prior to exposure to X-ray film. Radiolabeled p53 was readily observed.
cdc2/cyclin B phosphokinase assay. Purified human recombinant cyclin B1/cdc2 (Oncogene, Cambridge, Mass.), was incubated with hsRec2 for 10 or 60 minutes at 30° C., using the same buffer conditions as described for p53. An equal volume of 2× gel lading buffer was added (5), samples were heated at 100° C. for 10 minutes and run on an SDS gel, transferred to nitrocellulose and exposed to film. Radiolabeled cyclin B1 due to hsREC2 kinase activity was readily observed above the level of “autophosphorylation” of cyclin B1 by cdc2. Radiolabeled cdc2 was observed only in the hsREC2 containing reactions mixtures at 60 minutes but not at 10 minutes reaction time.
cdk2/cyclin E phosphokinase assay. GST-cyclin E was isolated from E. coli transformed with pGEX-2TcycE (A. Giordano, Thomas Jefferson University) and purified using Glutathione Sepharose 4B (Pharmacia, Piscataway, N.J.). The glutathione Sepharose GST-cyclin E was washed, and then stored as a 1:1 slurry in 50 mM Tris Cl, pH 7.4. For assays with cyclin E bound cdk2, purified cdk2 (kindly given to us by A. Koff, Sloan-Kettering, N.Y.) was incubated with cyclin E as described (6) and unbound cdk2 removed by washing prior to storage as a 1:1 slurry. Kinase assays were carried out with the immobilized GST-cyclin E with or without bound cdk2 otherwise using the same conditions described for p53. Phosphorylation of cyclin E and hsREC2 was readily observed in the absence of cdk2. In the presence of cdk2, autophosphorylation was seen, however, hsREC2 phosphorylation of cyclin E above that level was readily apparent.
In vitro associated between p53 and hsRec2. HsRec2 (5 μg) and 15 μl agarose-GST-p53 (Oncogene Sciences) were added to 0.5 ml of binding buffer (10%) glycerol, 50 mM Tris Cl, pH 7.4, 0.1 mM EDTA, 1 mM DTT, 0.02% NP40, 200 mM NaCl, 10 μg/ml aprotinin and leupeptin, and 20 μM PMSF. Following one hour at room temperature, the p53 agarose was pelleted and washed twice with buffer as above, using a higher concentration of detergent (0.1% NP40), and once with 50 mM TrisCl, pH 7.4, 10 mM MgCl 2 .
Association of in vitro translated hsRec2 with PCNA, p53 and cdc2. Xbal linearized pCMVhREC2 was first transcribed in vitro (Ambion, Austin Tex.) using 1 μg of the vector, and then translated in vitro along with Xef1 mRNA included in the kit as a positive control. Reticulocyte lysates containing Xef1 or hsRec2 translation products labeled with 35 S-methionine were incubated with 1.2 mg cell extract from HCT116 cells (50 mM TrisCl, pH 7.4, 120 mM NaCl, 0.5% NP40, 20 μM PMSF, 2 μg/ml pepstatin, and 10 μg/ml leupeptin and aprotinin, MB) for 2 hours, then 10 μg of antibodies against PCNA, p53 or cdc2 were added for an overnight incubation. On the following day, Protein A Sepharose was added for 2 hours, and pellets were washed four times with 500 μl MB. Pellets were suspended in 40 μl of sample buffer, boiled 10 minutes and 15 μl run on a 10% gel, then transferred to nitrocellulose to obtain a lower background, before exposure to X-ray film.
8
1
350
PRT
Homo Sapiens
1
Met Gly Ser Lys Lys Leu Lys Arg Val Gly Leu Ser Gln Glu Leu Cys
1 5 10 15
Asp Arg Leu Ser Arg His Gln Ile Leu Thr Cys Gln Asp Phe Leu Cys
20 25 30
Leu Ser Pro Leu Glu Leu Met Lys Val Thr Gly Leu Ser Tyr Arg Gly
35 40 45
Val His Glu Leu Leu Cys Met Val Ser Arg Ala Cys Ala Pro Lys Met
50 55 60
Gln Thr Ala Tyr Gly Ile Lys Ala Gln Arg Ser Ala Asp Phe Ser Pro
65 70 75 80
Ala Phe Leu Ser Thr Thr Leu Ser Ala Leu Asp Glu Ala Leu His Gly
85 90 95
Gly Val Ala Cys Gly Ser Leu Thr Glu Ile Thr Gly Pro Pro Gly Cys
100 105 110
Gly Lys Thr Gln Phe Cys Ile Met Met Ser Ile Leu Ala Thr Leu Pro
115 120 125
Thr Asn Met Gly Gly Leu Glu Gly Ala Val Val Tyr Ile Asp Thr Glu
130 135 140
Ser Ala Phe Ser Ala Glu Arg Leu Val Glu Ile Ala Glu Ser Arg Phe
145 150 155 160
Pro Arg Tyr Phe Asn Thr Glu Glu Lys Leu Leu Leu Thr Ser Ser Lys
165 170 175
Val His Leu Tyr Arg Glu Leu Thr Cys Asp Glu Val Leu Gln Arg Ile
180 185 190
Glu Ser Leu Glu Glu Glu Ile Ile Ser Lys Gly Ile Lys Leu Val Ile
195 200 205
Leu Asp Ser Val Ala Ser Val Val Arg Lys Glu Phe Asp Ala Gln Leu
210 215 220
Gln Gly Asn Leu Lys Glu Arg Asn Lys Phe Leu Ala Arg Glu Ala Ser
225 230 235 240
Ser Leu Lys Tyr Leu Ala Glu Glu Phe Ser Ile Pro Val Ile Leu Thr
245 250 255
Asn Gln Ile Thr Thr His Leu Ser Gly Ala Leu Ala Ser Gln Ala Asp
260 265 270
Leu Val Ser Pro Ala Asp Asp Leu Ser Leu Ser Glu Gly Thr Ser Gly
275 280 285
Ser Ser Cys Val Ile Ala Ala Leu Gly Asn Thr Trp Ser His Ser Val
290 295 300
Asn Thr Arg Leu Ile Leu Gln Tyr Leu Asp Ser Glu Arg Arg Gln Ile
305 310 315 320
Leu Ile Ala Lys Ser Pro Leu Ala Pro Phe Thr Ser Phe Val Tyr Thr
325 330 335
Ile Lys Glu Glu Gly Leu Val Leu Gln Ala Tyr Gly Asn Ser
340 345 350
2
1797
DNA
Homo Sapiens
2
cggacgcgtg ggcgcgggga aactgtgtaa agggtgggga aacttgaaag ttggatgctg 60
cagacccggc atgggtagca agaaactaaa acgagtgggt ttatcacaag agctgtgtga 120
ccgtctgagt agacatcaga tccttacctg tcaggacttt ttatgtcttt ccccactgga 180
gcttatgaag gtgactggtc tgagttatcg aggtgtccat gaacttctat gtatggtcag 240
cagggcctgt gccccaaaga tgcaaacggc ttatgggata aaagcacaaa ggtctgctga 300
tttctcacca gcattcttat ctactaccct ttctgctttg gacgaagccc tgcatggtgg 360
tgtggcttgt ggatccctca cagagattac aggtccacca ggttgtggaa aaactcagtt 420
ttgtataatg atgagcattt tggctacatt acccaccaac atgggaggat tagaaggagc 480
tgtggtgtac attgacacag agtctgcatt tagtgctgaa agactggttg aaatagcaga 540
atcccgtttt cccagatatt ttaacactga agaaaagtta cttttgacaa gtagtaaagt 600
tcatctttat cgggaactca cctgtgatga agttctacaa aggattgaat ctttggaaga 660
agaaattatc tcaaaaggaa ttaaacttgt gattcttgac tctgttgctt ctgtggtcag 720
aaaggagttt gatgcacaac ttcaaggcaa tctcaaagaa agaaacaagt tcttggcaag 780
agaggcatcc tccttgaagt atttggctga ggagttttca atcccagtta tcttgacgaa 840
tcagattaca acccatctga gtggagccct ggcttctcag gcagacctgg tgtctccagc 900
tgatgatttg tccctgtctg aaggcacttc tggatccagc tgtgtgatag ccgcactagg 960
aaatacctgg agtcacagtg tgaatacccg gctgatcctc cagtaccttg attcagagag 1020
aagacagatt cttattgcca agtcccctct ggctcccttc acctcatttg tctacaccat 1080
caaggaggaa ggcctggttc ttcaagccta tggaaattcc tagagacaga taaatgtgca 1140
aacctgttca tcttgccaag aaaaatccgc ttttctgcca cagaaacaaa atattgggaa 1200
agagtcttgt ggtgaaacac ccatcgttct ctgctaaaac atttggttgc tactgtgtag 1260
actcagctta agtcatggaa ttctagagga tgtatctcac aagtaggatc aagaacaagc 1320
ccaacagtaa tctgcatcat aagctgattt gataccatgg cactgacaat gggcactgat 1380
ttgataccat ggcactgaca atgggcacac agggaacagg aaatgggaat gagagcaagg 1440
gttgggttgt gttcgtggaa cacataggtt ttttttttta actttctctt tctaaaatat 1500
ttcattttga tggaggtgaa atttatataa gatgaaatta accattttaa agtaaacaat 1560
tccgtggcaa ctagatatca tgatgtgcaa ccagcatctc tgtctagttc ccaaatattt 1620
catcaccccc aaaagcaaga cccataacca ttatgcaagt gttcctattt ccccctcctc 1680
ccagctcctg ggaaaccacc aatctacttt ttttctatgg ctttacctaa tctggaaatt 1740
tcaaataaat gggatcaaat agtttcccaa aaaaaaaaaa aaaaaaaaaa aaaaaaa 1797
3
350
PRT
Mus Musculus
3
Met Ser Ser Lys Lys Leu Arg Arg Val Gly Leu Ser Pro Glu Leu Cys
1 5 10 15
Asp Arg Leu Ser Arg Tyr Leu Ile Val Asn Cys Gln His Phe Leu Ser
20 25 30
Leu Ser Pro Leu Glu Leu Met Lys Val Thr Gly Leu Ser Tyr Arg Gly
35 40 45
Val His Glu Leu Leu His Thr Val Ser Lys Ala Cys Ala Pro Gln Met
50 55 60
Gln Thr Ala Tyr Glu Leu Lys Thr Arg Arg Ser Ala His Leu Ser Pro
65 70 75 80
Ala Phe Leu Ser Thr Thr Leu Cys Ala Leu Asp Glu Ala Leu His Gly
85 90 95
Gly Val Pro Cys Gly Ser Leu Thr Glu Ile Thr Gly Pro Pro Gly Cys
100 105 110
Gly Lys Thr Gln Phe Cys Ile Met Met Ser Val Leu Ala Thr Leu Pro
115 120 125
Thr Ser Leu Gly Gly Leu Glu Gly Ala Val Val Tyr Ile Asp Thr Glu
130 135 140
Ser Ala Phe Thr Ala Glu Arg Leu Val Glu Ile Ala Glu Ser Arg Phe
145 150 155 160
Pro Gln Tyr Phe Asn Thr Glu Glu Lys Leu Leu Leu Thr Ser Ser Arg
165 170 175
Val His Leu Cys Arg Glu Leu Thr Cys Glu Gly Leu Leu Gln Arg Leu
180 185 190
Glu Ser Leu Glu Glu Glu Ile Ile Ser Lys Gly Val Lys Leu Val Ile
195 200 205
Val Asp Ser Ile Ala Ser Val Val Arg Lys Glu Phe Asp Pro Lys Leu
210 215 220
Gln Gly Asn Ile Lys Glu Arg Asn Lys Phe Leu Gly Lys Gly Ala Ser
225 230 235 240
Leu Leu Lys Tyr Leu Ala Gly Glu Phe Ser Ile Pro Val Ile Leu Thr
245 250 255
Asn Gln Ile Thr Thr His Leu Ser Gly Ala Leu Pro Ser Gln Ala Asp
260 265 270
Leu Val Ser Pro Ala Asp Asp Leu Ser Leu Ser Glu Gly Thr Ser Gly
275 280 285
Ser Ser Cys Leu Val Ala Ala Leu Gly Asn Thr Trp Gly His Cys Val
290 295 300
Asn Thr Arg Leu Ile Leu Gln Tyr Leu Asp Ser Glu Arg Arg Gln Ile
305 310 315 320
Leu Ile Ala Lys Ser Pro Leu Ala Ala Phe Thr Ser Phe Val Tyr Thr
325 330 335
Ile Lys Gly Glu Gly Leu Val Leu Gln Gly His Glu Arg Pro
340 345 350
4
1525
DNA
Mus Musculus
4
gggagccctg gaaacatgag cagcaagaaa ctaagacgag tgggtttatc tccagagctg 60
tgtgaccgtt taagcagata cctgattgtt aactgtcagc actttttaag tctctcccca 120
ctagaactta tgaaagtgac tggcctgagt tacagaggtg tccacgagct tcttcataca 180
gtaagcaagg cctgtgcccc gcagatgcaa acggcttatg agttaaagac acgaaggtct 240
gcacatctct caccggcatt cctgtctact accctgtgcg ccttggatga agcattgcac 300
ggtggtgtgc cttgtggatc tctcacagag attacaggtc caccaggttg cggaaaaact 360
cagttttgca taatgatgag tgtcttagct acattaccta ccagcctggg aggattagaa 420
ggggctgtgg tctacatcga cacagagtct gcatttactg ctgagagact ggttgagatt 480
gcggaatctc gttttccaca atattttaac actgaggaaa aattgcttct gaccagcagt 540
agagttcatc tttgccgaga gctcacctgt gaggggcttc tacaaaggct tgagtctttg 600
gaggaagaga tcatttcgaa aggagttaag cttgtgattg ttgactccat tgcttctgtg 660
gtcagaaagg agtttgaccc gaagcttcaa ggcaacatca aagaaaggaa caagttcttg 720
ggcaaaggag cgtccttact gaagtacctg gcaggggagt tttcaatccc agttatcttg 780
acgaatcaaa ttacgaccca tctgagtgga gccctccctt ctcaagcaga cctggtgtct 840
ccagctgatg atttgtccct gtctgaaggc acttctggat ccagctgttt ggtagctgca 900
ctaggaaaca catggggtca ctgtgtgaac acccggctga ttctccagta ccttgattca 960
gagagaaggc agattctcat tgccaagtct cctctggctg ccttcacctc ctttgtctac 1020
accatcaagg gggaaggcct ggttcttcaa ggccacgaaa gaccataggg atactgtgac 1080
ctttgtctag tgctgattgc atgtgactca tgaaatgaaa caggactgcg ctgcttggaa 1140
aaaggaaacg gaagccaaca taatgaggat taattggttg gttgctgttg aggtggtaac 1200
agtgatttca gacccggaag gtgaagatga agaagccttt atccagtctc tggatgcaga 1260
ggctaggggc tccaccaccg tgggatgtca gcggccatcg taataatttg cacttacaca 1320
agcacctttc agccatgccc ctcaaagtgg ttcagccaca ttaattaatt aaagcccaca 1380
atccccctag ggagagcagg agggggacta acaagatttg taattacaga agggaaaatt 1440
tccgaataaa gtattgttcc gccaaaaaaa aaaaaaaaaa aaaaaaaaaa aaaaaaaaaa 1500
aaaaaaaaaa aaaaaaaaaa aaaaa 1525
5
7
PRT
Artificial Sequence
Substrate of ser/thr kinases
5
Leu Arg Arg Ala Ser Leu Gly
1 5
6
32
DNA
Artificial Sequence
PCR Primer
6
gagctcgagg gtacccatgg gtagcaagaa ac 32
7
13
PRT
Artificial Sequence
Fragment of Naturally Occurring Protein
7
Arg Arg Leu Ile Glu Asp Ala Glu Tyr Ala Ala Arg Gly
1 5 10
8
20
PRT
Artificial Sequence
Fragment of Naturally Occurring Protein
8
Val Glu Ile Ala Glu Ser Arg Phe Pro Arg Tyr Phe Asn Thr Glu Glu
1 5 10 15
Lys Leu Leu Leu
20
|
The invention includes a method of phosphorylating a serine containing substrate by incubating the substrate with ATP and an enzyme that is hsRec2 or muRec2 or a derivative thereof. The natural substrates of the kinase activity of Rec2 are the cell cycle control proteins such as p53 and cyclin E. The over expression of Rec2 is known to cause cell-cycle arrest and apoptosis and the invention discloses that these effects are kinase mediated. Accordingly, the invention provides a method of assessing antagonists and agonists of Rec2, which antagonists and agonists would have pharmacological activity. The invention further discloses that there is specific binding between hsRec2 and at least three cell cycle control proteins: p53, PCNA and cdc2.
| 2
|
BACKGROUND OF THE INVENTION
The invention relates generally to clutch mechanisms for the selective transmission of rotary energy and more particularly to clutch mechanisms which eliminate or substantially reduce partial coupling, i.e., drag, between the input and output members when the clutch is disengaged.
Clutch mechanisms provide selective transmission of rotary energy over a broad range of power transfer capabilities. In addition to the basic parameter of power transfer capability, such considerations as overall size, cost, service life and serviceability dictate the ultimate design of any particular clutch. Single or dual faced plate type clutch mechanisms such as disclosed in U.S. Pat. No. 1,832,527 and multiple disk clutches which contain a plurality of interleaved clutch plates such as the device disclosed in U.S. Pat. No. 987,945 represent but two of many general styles of clutch design. Mechanically activated clutches such as disclosed in either of the above recited patents or fluid or air actuated clutches such as those disclosed in U.S. Pat. Nos. 2,799,375, 3,435,936, or 3,782,516 illustrate two other clutch classifications.
A difficulty common in many clutch mechanisms, especially those incorporating plural clutch elements, centers on achieving positive and total mechanical isolation of the input and output components when the clutch is deactivated. Stated differently, the residual coupling or drag between the input and the output components of a deactivated clutch is undesirable. First of all, such residual coupling or drag may increase standby or idle power requirements and thus reduce overall efficiency, especially in a mechanical system where the clutch is deactivated and the prime mover idles for a significant portion of the operating cycle. Secondly, positive disconnection will typically improve the life of the clutch inasmuch as reduced scrubbing and sliding of the clutch elements against one another during idle and thus reduce both the generation of frictional heat and consequently overall operating temperatures.
SUMMARY OF THE INVENTION
The instant invention comprehends a low drag air clutch having a generally circular housing within which are disposed a clutch plate, a pair of spaced apart friction disks disposed on opposite sides of the clutch plate and a pneumatic operator assembly suitable for applying force to the disks and plate and providing frictional engagement therebetween. One of the friction disks is fixedly retained within and rotates with the housing. The other friction disk is movable and is coupled to the housing through interengaging sets of helical splines, preferably disposed about its periphery. Mating splines are disposed in a complementary fashion within the housing and permit limited axial and rotational movement. The clutch plate is disposed between the fixed and movable friction disks and is mounted upon a rotatable member by interengaging sets of helical splines. The pneumatic operator assembly comprises a circular bladder or similar device and a spring biased pressure plate which is operably coupled to and axially translates the movable friction disk and clutch plate. The housing itself preferably functions as the input drive member and the member upon which the clutch plate is disposed functions preferably as the output member.
When compressed air is supplied to the pneumatic operator assembly, the movable friction disk is forced against the clutch plate and the clutch plate in turn is forced into fricitional engagement with the fixed friction disk thereby transferring rotational energy from the input member and housing to the output member. Releasing compressed air from the operator assembly relieves the compressive force against the clutch components and power transmission substantially ceases. The spring biased pressure plate ensures collapse of the pneumatic operator. Separation of the clutch plate from each of the friction disks is ensured by the action of the sets of helical splines. The sense of the splines, either left handed or right handed, is selected such that continuing rotation of the drive housing, particularly any relative rotation greater than that of the friction disk mounted upon the helical splines, causes the friction disk to back away from the clutch plate. This axial motion occurs primarily when the friction disk rubs against the clutch plate and is thus urged to rotate at a speed lower than the speed of the housing. In a similar manner, the helical spline interconnection between the clutch plate and the output member axially translates the clutch plate away from the fixed friction disk secured to the housing toward the movable friction disk if minimal contact and speed differences occur. In their deactivated state, the clutch elements will be urged into axial positions wherein certain minimum spacings will exist therebetween and drag will be either eliminated or reduced to a negligible level. It should be understood that the sense of the helical splines must be selected to match, first of all, the direction of rotation of the clutch as will be fully described subsequently.
Therefore it is an object of the instant invention to provide a selective power transmission device which exhibits negligible input to output coupling when in a deactivated state.
It is a further object of the instant invention to provide an air operated clutch which exhibits low drag in a deactivated state.
It is a still further object of the instant invention to provide a low drag, air operated clutch having clutch elements disposed for limited axial translation on sets of helical splines.
It is a still further object of the instant invention to provide a low drag, air operated clutch having components interconnected by helical spline sets.
It is a still further object of the instant invention to provide a low drag, air operated clutch mechanism which is both compact and of straightforward, easy to manufacture design.
Still further objects and advantages of the instant invention will become apparent by reference to the following description and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view in partial section of a low drag clutch according to the instant invention;
FIG. 2 is a fragmentary elevational view of a ribbed pressure plate of a low drag clutch according to the instant invention;
FIG. 3 is a fragmentary elevational view with portions broken away of the clutch plate of a low drag clutch according to the instant invention;
FIG. 4 is a fragmentary sectional view of a low drag clutch according to the instant invention in a deactivated state; and
FIG. 5 is a fragmentary sectional view of a low drag clutch according to the instant invention in an activated state.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, a low drag clutch mechanism according to the instant invention is illustrated and generally designated by the reference numeral 10. The clutch mechanism includes a generally circular housing assembly 12 which receives and supports the other components of the clutch mechanism 10 in proper operating relationship. The housing assembly 12 comprises a centrally disposed annulus 14 having a radially extending flange 16 formed integrally therewith. The radially inwardly directed portion of the flange 16 serves to retain other components of the clutch mechanism 10 as will be subsequently described. The radially outwardly directed portion of the flange 16 includes a plurality of equally circumferentially spaced apart openings 18 through which a like plurality of threaded fasteners such as bolts 20 may be utilized to secure a suitably flanged input or drive member 24 having threaded openings 26 to the clutch mechanism 10 in a conventional manner. Disposed adjacent the opposite end of the annulus 14 is a circular cover plate 28. The cover plate 28 defines a plurality of openings 30 disposed in equally spaced apart relationship about its periphery through which threaded fasteners 32 extend into complementarily threaded passageways 34 in the annulus 14 to secure the cover plate 28 to the annulus 14 in a coventional manner.
Compressed air is supplied to the rotating clutch mechanism 10 through a supply line 40 and a rotating union 42. The rotating union 42 provides an interconnection between the stationary air supply line 40 and the rotating clutch mechanism 10 and is a conventional component of pneumatic clutch art as those skilled in this art will readily appreciate. The rotating union 42 is secured by suitable interengaging male and female threads 44 and 46, respectively, to a centrally disposed hub 48 which defines a pair of threaded outlet passageways 50. The threaded passageways 50 receive suitable complementarily threaded fittings (not illustrated) which are terminating components of a like number of air lines 54. The opposite ends of air lines 54 are likewise terminated by suitable threaded fittings 56 which are received in complementarily threaded inlet fittings 58. The inlet fittings 58 communicate with an interior chamber 62 of a circular air bladder 64 fabricated of an elastomeric, resilient material.
Referring now to FIGS. 1 and 2, a ribbed, radially extending pressure plate 70 is disposed axially adjacent the face of the air bladder 64 opposite the cover plate 28. The pressure plate 70 defines an array of radially disposed, spaced apart ribs 72. The ribs 72 both improve thermal isolation between the air bladder 64 and other components of the clutch mechanism 10 and define radially extending channels 74 through which a flow of cooling air may pass. A plurality of mounting assemblies 76 disposed uniformly about the axis of the ribbed clutch plate 70 provide limited, spring biased axial travel while radially positioning and supporting the pressure plate 70 on the cover plate 28. Each of the mounting assemblies 76 is disposed between axially aligned apertures 78 and 80 defined by the ribbed pressure plate 70 and cover plate 28, respectively, and includes an elongate fastener such as a threaded bolt 82, a locking nut 84, and a compression spring 86 disposed between the outer face of the cover plate 28 and the locking nut 84. The mounting assemblies 76 cooperate with the air bladder 64 to provide bi-directional axial translation of the ribbed pressure plate 70 in a conventional manner; pressurization of the air bladder 64 translating the ribbed pressure plate 70 away from the cover plate 28 and depressurization of the air bladder 64 resulting in translation of the ribbed pressure plate 70 toward the cover plate 28 due to the bias provided by the compression springs 86.
Referring again to FIG. 1, the inner surface of the annulus 14 defines an array of helical splines 90. The female splines 90 extend axially from a region adjacent the ribbed pressure plate 70 to the inwardly directed portion of the flange 16 and may be of any suitable profile, such as the buttress profile illustrated. A first friction disk 92 is disposed generally axially adjacent the ribbed pressure plate 70 and includes a complementary array of helical splines 94 disposed about its periphery. The first friction disk 92 may be fabricated of any suitable clutch facing material, material which will be dictated by the intended application of the clutch mechanism 10 as those skilled in the art will readily understand. A second friction disk 96 of identical construction having an array of peripherally disposed helical splines 98 is disposed within the annulus 14 adjacent the inwardly directed portion of the flange 16. The second friction disk 96 is fixedly retained in contact with the inwardly directed portion of the flange 16 by a retaining ring 100 which is received within a circumferential groove 102 and the splines 98 engage the splines 90 on the inside of the annulus 14.
Referring now to FIGS. 1 and 3, the clutch mechanism 10 also includes a movable clutch plate 106 which is positioned ganerally between the first and second friction disks 92 and 96. The movable clutch plate 106 inclues an array of helical splines 108 which engage a complementary array of helical splines 110 which are disposed about the periphery of a hub 112. A retaining ring 116 is seated within a complementarily sized groove 118 defined by the helical splines 110. The movable clutch plate 106 thus rotates with the hub 112 and may translate axially between the second friction disk 96 and the retaining ring 116. The hub 112 is secured to a drive shaft 120 through suitable means such as a key 122 and the shaft 120 is rotatably supported within the flanged drive member 24 by means of suitable anti-friction bearings such as the ball bearing 124. As shown in FIG. 3, the movable drive plate 106 defines a plurality of through axial openings 130. The axial openings 130 are disposed in a generally circular, spaced apart arrangement and communicate with a like number of radially disposed passageways 132. The axial openings 130 and radial passageways 132 provide a flow path for air which assists in the removal of frictionally generated heat from the movable clutch plate 106.
Referring now to FIG. 1 and particularly to FIG. 4, the deactivated state of the clutch mechanism 10 will first be described. In this state, the bladder 64 is collapsed due to the absence of significant air pressure and the compression springs 86 of the mounting assemblies 76 have retracted the ribbed pressure plate 70 to its relaxed position as illustrated in FIG. 4. The housing assembly 12 is typically the driven member in clutch mechanisms of this type and will therefore be appreciated that the housing assembly 12 and all the components of the clutch mechanism 10 attached thereto will be rotating with it. Similarly, the movable clutch plate 106, the hub 112 and the shaft 120 will typically function as the output members and they will either be stationary or rotating at some slower speed. Due to the separation of the first and second friction disks 92 and 96 from the adjacent face of the movable clutch plate 106, no power will be transferred through the clutch mechanism 10.
Referring now to FIG. 5, compressed air has been supplied to the bladder 64 and the ribbed pressure plate 70 has been urged axially to the left in FIG. 5, forcing the first friction disk 92 into contact with one face of the movable clutch plate 106 and subsequently forcing the movable clutch plate 106 into contact with the second friction disk 96. In this condition, power supplied to the housing assembly 12 through the flange drive member 24 is transferred through the elements of the clutch and out the shaft 120 in a substantially conventional fashion.
Referring again to FIG. 4, the pressure of the air within the bladder 64 has been relieved and the ribbed pressure plate 70, due to the bias of the compression springs 86, has returned to its deactivated position as illustrated in FIG. 4. The arrays of helical splines 90 and 94 and 108 and 110 now cooperate to fully separate and substantially eliminate drag by axially displacing the first friction disk 92 and the movable clutch plate 106 in response to small inertial and frictional forces. As deactivation of the clutch mechanism 10 occurs through the relaxation of the bladder 64 and retraction of the ribbed pressure plate 70, the speed of rotation of the shaft 120 will typically become less than that of the housing assembly 12 and specifically the fixed disks 92 and 96. In this operating condition, any contact between the movable clutch plate 106 and the second friction disk 96 will result in the arrays of helical spline 108 and 110 translating the movable clutch plate 106 away from the second friction disk 96. Similarly, any contact between the movable clutch plate 106 and the first friction disk 92 will result in the first friction disk 92 being translated axially away from the movable clutch plate 106, to the right, as viewed in all the drawing figures. Thus, contact between the friction disks 92 and 96 and the movable clutch plate 106 will tend to further separate these elements and eliminate or reduce to negligible levels, the mechanical coupling and thus drag between the flanged input member 24 and the output shaft 120. It has been found desirable to permit a maximum face-to-face separation between the movable clutch plate 106 and either of the first or second frictional disks 92 or 96 of about 0.060 to 0.090 inches maximum. These dimensions should be considered to be of an exemplary nature only and the exact maximum separation may be adjusted as necessary in response to various application and performance parameters.
It should, of course, be recognized that the sense of the splines 90, 94, 98, 108, and 110, that is , whether they are right hand or left hand, is both critical and determined by considerations of rotation. For example, let it first be assumed that the rotation of the housing assembly 12 is clockwise as viewed from the drive end, i.e., counterclockwise in FIG. 1. In this instance and given the fact that the shaft 120 and associated components slows when the clutch mechanism 10 is deactivated, all the sets of splines 90, 94, 98, 108 and 110 should be of right hand sense. Conversely, if the direction of drive is counterclockwise when viewed from the input end, i.e., clockwise when viewed in FIG. 1, the sets of splines 90, 94, 98, 108 and 110 should be of left hand sense as illustrated in FIG. 1. It should also be noted that if, for some peculiar application, the driven member such as the shaft 120 increases in speed when the clutch mechanism 10 is disengaged the foregoing rules for choice of spline sense should be reversed.
The foregoing disclosure is the best mode devised by the inventor for practicing this invention. It is apparent, however, that devices incorporating modifications and variations will be obvious to one skilled in the art of clutches. Inasmuch as the foregoing disclosure is intended to enable one skilled in the pertinent art to practice the instant invention, it should be construed to be limited thereby but should be construed to include such aforementioned obvious variations and be limited only by the spirit and scope of the following claims.
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A low drag air clutch for use in power transmission systems includes a rotating housing containing a clutch plate, a pair of spaced apart friction disks disposed on opposite faces of the clutch plate and a pneumatic operator assembly. One of the friction disks is fixedly retained in the housing. The other is coupled to the housing through arrays of helical splines which permit limited axial and rotational movement. The pneumatic operator assembly is disposed adjacent, engages and axially translates the movable friction disk. The clutch plate is coupled to a shaft member through arrays of helical splines. Activation of the pneumatic assembly engages the clutch elements. When deactivated, the rotation of the clutch elements and contact therebetween causes the helical spline arrays to urge the clutch plate and friction disks apart in order to eliminate partial mechanical coupling, i.e., drag, through the clutch.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This non-provisional application claims priority to the provisional application with a Ser. No. of 60/723,534 with a filing date of Oct. 4, 2006 which is commonly owned by the same inventor.
BACKGROUND OF THE INVENTION
[0002] Various types of decorative panels, wainscot, chair rails, and the like, have long been used upon the surface of walls, normally as a lower segment, to decorate a wall, but also, to furnish a protective covering, for the wall, so that whatever furniture, individuals, or other items encounter the wall, damage will be minimized. Nevertheless, these types of decoration added to a wall have also been used for just that purpose: to add to the pleasing aesthetic appearance of a wall and thus enhance the attractiveness of the room.
[0003] As is well known, wainscots have been applied to the walls in rooms, particularly of the more fancy homes, that were built at the turn of the twentieth century. Early on, the cheaper and faster to construct housing in the boom years of the late 1940s and 1950s and the minimalist homes designed in the 1960s and 1970s are receiving much needed decor upgrades, often from decorators, handymen, kitchen and bath re-modelers, and quite often the homeowners themselves. Additional, new homes, both high end and modest, are receiving the architectural attention that they lacked for many years. The increasing popularity of traditional and classical style of home décor has usage of architectural trim exploding. The looks of goods sold by stores such as Pottery Barn, Crate & Barrel, and Restoration Hardware are desired by homeowners and architects alike. Many of these architectural elements are from the English Georgian period circa the 1700s, the American Federal period, the Arts and Craft movement, and the Victorian style. These architectural inspirations coupled with the increased availability of numerous styles of trim, chair rails, crown molding, and baseboards, has brought about the return of classical trim in homes, not only the high end residences but the average American home.
[0004] The security of real estate investments in residential housing has lead to a robust grown in the home improvement and home building market. When a home's worth is often linked to the owner's ability to use its equity, home improvement is on the top of homeowner's minds. Homes builders are equally motivated to use value added options to achieve higher sales volumes and the sought after higher sales margins. This growth appears in the number of successful large and small home improvement companies, home improvement centers, and construction companies.
[0005] The push for home improvement and the offerings for easy solutions to homeowners have left a gap in the areas that require expensive equipment and moderate skill in woodworking. Finished millwork proves difficult for homeowners to find at local home improvement centers nor can builders provide at an affordable price.
[0006] Currently, achieving a classic look varies from wall covering to special paint finishes, wall frames, chair rails, and to wainscoting. Most home owners live with the walls at the time of purchasing the house, while struggling to find a way to attain that classic look for the rooms that will host their friends and family, and appears luxurious. Nothing completes or finishes a room like wainscot, which offers a special look but at a steep price.
[0007] Presently, no wainscoting is available for the average homeowner or builder seeking a low price optional extra for a house. Existing products generally remain within chair rails or wall frames. The cost of labor for installing a wall frame makes it cost prohibitive. Little on the market today compares to the classic look of raised panel wainscot.
[0008] Traditional wainscot consists of long wooden pieces, or rails, which run horizontally along a wall's length, above and below the wainscot panels, short vertical pieces, or stiles, that separate the panels, and the panels themselves. The parts are generally fit with tongue and groove joinery upon perimeter edges. Each piece is likely custom cut for installation.
SUMMARY OF THE INVENTION
[0009] This invention relates generally to the addition of pre-fabricated modular, or complete, architectural wall panels, in the nature of a wainscot, that may be conveniently, easily, and properly, fitted to a wall during construction or renovation.
[0010] The wainscot wall panel of this invention is completely fabricated, or made of, finished wood components, with raised panels and stiles forming the wainscot panel. The design reflects traditional custom built raised panel type wainscoting: raised panels framed by rails and stiles. The panels are cut, or milled, from MDF (Medium Denisty Fiber Board), natural wood products, or other materials, such as composite materials. The unique proportions of the panel with respect to the raised panel detailing allows for greater flexibility and versatility along any length wall or with any width window, to any height from the floor, while maintaining a custom, crisp, clean look to the finished room.
[0011] The wall panel of this invention is detailed with a number of raised panels, evenly spaced, and separated by stiles. At one end, an assembly of panel ends with one-half of a stile. This allows for abutting together adjacent panels, of identical panel design, resulting in a continuous pattern of raised panels alternating with stiles, all evenly spaced. The opposite panel ends with a flat plane, or stile, with approximately the same width as the raised panels. This allows for trimming of the panel's length to accommodate the wall's dimensions without interfering with the raised panel and stile pattern.
[0012] The wall panel dimensions are consistent with typical residential room sizes to minimize the number of panels required, the installation time, and ease of their transfer during construction. The standard panel proportions and design allows for the wide stile end portion of panel to be trimmed, as with one vertical cut, to accurately accommodate differing wall dimensions. Because of its symmetry, the same top and bottom rail heights, the panel can be rotated one-hundred and eighty (180) degrees to accommodate a finished left or right hand corner while allowing continuity of panel detail, rail, and stile pattern spacing.
[0013] Addressing wall dimensions that are greater or less than two wainscot wall panels butted together, may require an additional vertical cut down the center of a stile pattern to increase or decrease the overall modular length of the wall panels.
[0014] Due to the spacing on the panel, the panel's proportions, and its standard dimensions, working the wainscot wall panel below windows that are less than the standard height of the panel is greatly simplified and requires no custom made panels or milling as later shown in FIG. 7-9 . The wainscot wall panel can be turned vertical, and trimmed appropriately by the installer, to address the particular window's height and width. Additionally, a continuous raised panel line above the baseboard can be maintained if desired. The panel dimensions and pattern placement allows for trimming to suit narrower windows, while maintaining a consistent stile width or pattern throughout the wall.
[0015] The unique proportions of the panels include a raised center panel surrounded by perimeter flat flanges. These proportions and features, with respect to the raised panel detailing, allow for greater flexibility and versatility with any length wall or any width window at any height from the floor, while maintaining a custom, crisp, clean look to the finished room.
[0016] The raised panel, stile and rail patterns for assembling the wainscot of this invention may be categorized as follows:
[0017] 1. The pattern is achieved by traditional methods of assembling stiles, rails, and raised panels to the approximate dimensions noted above with symmetrical top and bottom rails, one-half stile on one end, and approximately one full panel width stile on the opposite end. The raised panel portions may have other patterns cut into them, to furnish additional aesthetic detailing for the formed panel.
[0018] 2. The pattern is milled, or routed, into the center piece to separate rails to the appropriate proportions as noted above. The three piece approach allows for the custom appearance to be maintained, a butt joint between the rails and stiles, as well as crisp ninety (90) degree corners in the detail pattern.
[0019] Additionally, when natural wood products are used and grain direction is important, this approach allows for the stiles and patterns to maintain vertical orientation of the grain, and the rails to maintain a horizontal grain, further preserving the custom look in a standard panel approach. The raised panel portions may have other patterns cut into them, to furnish additional aesthetic detailing for the formed panel.
[0020] 3. The pattern is milled, or routed, into one solid board with the appropriate proportions as noted above. Contours of the rails, stiles, and raised panels are cut into the single work piece and nothing is cut separately. The raised panel portions may have other patterns cut into them, to furnish additional aesthetic detailing for the formed panel
[0021] 4. The pattern is cast from a mold and inserted into an opening cut in the board with the appropriate proportions noted above. This results in one board with the pattern of rails, stiles and raised panels.
[0022] 5. The entire panel and detailing, with the appropriate proportions noted above, can be formed by an injection molding process.
[0023] Regardless of panel construction methods, the panels can be permanently attached to existing wall surfaces, such as drywall, brick, plaster, and the like, with common fasteners such as nails, screws or construction adhesive. In new construction and in certain applications, panels can be fixed directly to the wall studs.
[0024] Additional trim and base boards can be added by the installer to dress up the wall panels and add the finished look to the final installation. Screws or nails used to secure the panels can be hidden by the baseboard or chair rail trim at the bottom and top of the panels eliminating the need to fill or patch the panels.
[0025] Openings for electrical outlets, phone jacks, and the like, must be measured and cut by the installer. The raised panel, rail, and stile pattern is designed for standard height outlets, to be cut into the raised panel portion of the pattern, without interfering with the pattern contours.
[0026] It is, therefore, the principal object of this invention to provide wainscot wall paneling that may be pre-fabricated into custom segments, which may be easily cut and fitted into the construction or renovation of a room for a home or building.
[0027] Another object of this invention to provide for completely pre-fabricated and primed or wood finished raised panel stile wainscoting wall panels, that may be readily applied to the wall during new construction, or during room renovation.
[0028] Another object of this invention is to provide custom made pre-assembled wainscot panels that may be readily fitted and applied into a room or building, to alleviate the need to cut custom pieces and assemble such overall panels within a room during its building or renovation.
[0029] Another object of this invention is to provide means to facilitate and ease the method in which wall paneling may be applied in a building.
[0030] A further object of this invention is to provide a means for the manufacturer and assembly of wainscot wall panels at a manufacturing plant, for shipment to a building site, installer, or a retail outlet.
[0031] These and other objects may become more apparent to those skilled in the art upon review of the summary of the invention as provided herein, and upon undertaking a study of the description of its preferred embodiment, in view of the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] In referring to the drawings,
[0033] FIG. 1 shows an assembly of a pre-manufactured standard wainscot wall panel;
[0034] FIG. 2 shows the various components that are pre-fitted and assembled into a standard wainscot wall panel, FIG. 2A shows an exploded view of the components, FIG. 2B describes the fit of the raised panel into a rail, FIG. 2C then shows the fit of a rail with a stile or end panel;
[0035] FIG. 3 shows the various sections that are joined together generally by tongue and groove joinery to form the pre-manufactured wall panels, FIG. 3A shows an exploded view of the components and the single piece panel, FIG. 3B illustrates the fits of the raised panel into a stile, FIG. 3C describes the fit of a rail to a raised panel;
[0036] FIG. 4 shows the complete one piece construction of the pre-manufactured standard wainscot wall panel, FIG. 4A describes the routing that forms the apparent joint of a raised panel with a stile;
[0037] FIG. 5A shows the various wall panel arrangements for various lengths of walls and FIG. 5B describes the various wall panel arrangements, including shortened panels, around a window opening;
[0038] FIG. 6A shows the individual standard panels cut to appropriate lengths and assembled into a room along a wall following a panel layout shown in FIG. 6B ;
[0039] FIG. 7 shows a perspective view of the panels as assembled into a room, along a wall with a window, noting the method of fitting below a lower window structure;
[0040] FIG. 8 shows the various routing and shaping details for the panels, rails, stiles, and even the raised panels for the wainscot of this invention along with further routing and shaping details for one piece pre-fabricated panels;
[0041] FIG. 9 describes the continuous routing of a single panel; and,
[0042] FIG. 10 provides a view of the raised panel centrally located within the prefabricated wainscot, and alternate detailing for aesthetics of the formed panel.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0043] In referring to the drawings, and in particular FIG. 1 , this particular figure shows in various views the application and usage of the pre-fabricated wainscot wall panels 1 of this invention. Preferably the panels are made of wood. They may be simply applied end to end, as along their mating of the one-half stiles, as at 2 , together, in order to form a complete stile, such as shown normally at 3 , with the upper and lower rails 4 and 5 , respectively, forming the peripheral structure for the raised panels 6 for each panel section 1 . As can also be seen in FIG. 1 , these panels 1 ′ may be abutted beneath a window, as at W, to add to the attractiveness of the room, as the panels are being installed during custom construction, or during remodeling of a room.
[0044] These types of panels can be fabricated either custom on the jobsite or standardized at the manufacturing plant, generally in the manner as shown in FIG. 2 , wherein the miscellaneous components that make up a panel can be seen at FIG. 2A , in an exploded view, but that when the various components are assembled, they are formed into the complete panel, as noted at 8 , and can be shipped from the factory to the jobsite, where they may be applied to a wall. The various components that make up the panels can be seen at FIG. 2B , where a stile and rail construction, using mortis and tenon joinery can be used for assembling the components together, in the construction of a complete panel. And, as can be noted, half stiles, as at 10 , can be formed at either end of the panel, so that when adjacent panels are applied in line, along an entire wall, a pair of the half stiles form a full stile, of the type and width as shown at 11 , to add continuity to the paneling when applied, one next to the other, during construction. The rail and stile connection, as at FIG. 2C , forms the upper connection between a rail, and a stile, during assembly.
[0045] A second method for this invention, for construction of the wainscot wall panels can later be seen in FIGS. 8, 9 . In this instance, rather than assembling components into the formed panel, a sheet of wood, that will be of a height for the intended panel, and having a corresponding width to the width of the panel desired, can be routed by a bit 17 , in the manner as shown in the right of FIG. 8 , wherein longitudinal and lateral routing, through the use of a computerized router, can take the paths for routing as shown at 13 , while additional routing can be done at the upper and lower rail sections, as 14 . Then, the upper rail and bottom rail can be applied, as shown at 15 and 16 respectively, to complete the finally assembled panel. Additional pathways of the bit 17 are shown in the left of FIG. 8 that form the raised panel 6 and the rails 4 , 5 .
[0046] Nevertheless shown in FIG. 9 , most of the components used to form the panel, will be routed by a bit 17 , and cut from a singular board, rather than requiring the custom fitting of a variety of pre-cut sections together, in the manner as previously explained for FIG. 2 . FIG. 9 also shows another tool path detail, for the routing and shaping details, for construction of the wainscot wall panels, in a manner as previously described in 8 . This tool path is continuous as the tool need not be lifted from the work piece, thus reducing manufacturing time and cost. Hence, the wainscot wall panels can be constructed and formed in two ways, one either by custom assembly, at the plant, or by significant routing, through a continuous pre-programmed routing technique in order to cut the paneling into the appearance of a wainscot, for final application of its rails, to complete a panel ready for shipment.
[0047] These types of panels can be constructed to almost any size, have a standardized height of three to four feet, and a standardized width from four to eight feet, depending upon the dimensions required for the building in which these panels are to be installed. A computer can regulate these dimensions at a manufacturing plant, when a variety of such panels are to be manufactured, for a particular job. Essentially, the invention eliminates the need for custom cutting and assembly of the wainscot, at the jobsite. Custom cutting can be a very expensive operation with costly wood or other products and skilled labor to complete such tasks. In this invention, the wainscot panels are constructed at the manufacturing plant, shipped to a jobsite and installed by nails, manufacture's glue, adhesives and the like, to locate the panels in place rapidly to finish a job.
[0048] Alternatively, the wainscot panels, including their constituent parts of rails, stiles, and raised panels, can be formed by pressure with lumber or other material placed within a mold. The mold has the shapes of the desired finished panel and then the mold is applied to a single sheet of material at high pressure. The high pressure alters the planar sheet into the shape of the mold. This method of assembly is particularly suited to glue laminated material where a semi-plastic mixture of wood chips and resin flows into a mold and then attains a finished shape under the pressure of the mold. Alternatively, the panels can be made from wood chips, chip board, plastics and composites.
[0049] FIG. 3 shows further assembly of the pre-manufacture's standard wainscot wall panel, in the manner as previously explained in FIG. 2 , showing how the various components may be custom fitted, into a main panel section, at the manufacturing plant, or which may even be assembled at the job site. An exploded view in FIG. 3A shows the pieces that assemble into a panel upon the job site bounded by rails. FIG. 3B illustrates the shaping of the connection that forms a wall panel adjacent to a stile. The shaping has sharp features to denote the edge of a stile and more gradual features to denote the border of the wall panel 6 . FIG. 3C describes the joining of a wall panel to a rail with an end panel, here towards the right, beyond the foreground of the joint. The wall panel provides a tenon that inserts into a mortis like groove upon the longitudinal edge of a rail.
[0050] FIG. 4 shows further construction methods for a one piece construction of a wainscot wall panel, in preparation for assembly and usage. The single piece panel has a design manufactured by routing of the design by a computer controlled router or by a press having a mold bearing the design. FIG. 4A further illustrates the routing of a wall panel at the border where the raised panel abuts a stile 10 , 11 . The raised panel has gradual features denoting its border while the stile has sharper features.
[0051] FIG. 5A shows the various lengths of wall paneling, that may be made to specified wall sizing details, at the manufacturing plant, for later assembly within rooms. The assembly may apply the wall panel directly against the wall, throughout its entire length, or as located adjacent a fireplace, or windows following the template in FIG. 5B . Other standard type cuts can be made at the job site, by the installer, where the paneling may be required to fit around or under windows, and the like.
[0052] FIG. 6A shows a finished application of the wainscot wall panels primarily to a room wall, along the length of a wall, and secondarily below a window. As shown in FIG. 6B , four panels complete the entire structured paneling, for half of the room.
[0053] FIG. 7 shows a perspective view of the application of the wainscot wall panels around a window and along a wall. Here the panels below the window sill are of lesser height than the remaining panels throughout the room.
[0054] FIG. 10 provides a view of the raised panel, furnished and located centrally within the prefabricated wainscot. This figure also discloses how other detailing may add to the aesthetics of the formed panel, whether through custom assembly or routing. As before, this is for the paneling constructed through the continuous routing method, at the manufacturing plant, to provide finished paneling with detailed dimensions, ready for shipment and application to a room, simply through minor cutting, and then through application by means of nails, or construction adhesive, to the wall of the room being constructed, or remodeled.
[0055] The foregoing provides a general description of the details of assembly, of the wainscot wall panels, at the manufacturing plant, rather than requiring the custom cutting and assembly upon a room wall, by a carpenter, as done in prior art wainscot paneling of a building or room. The preceding description shows the application of wainscot paneling can be done rapidly, less expensively, but yet have just as attractive appearance and more uniform dimensions, through the usage of this invention.
[0056] Variations or modifications of the subject matter of this invention may occur to those skilled in the art upon reviewing the development as described herein. Such variations, if within the spirit of this development, are intended to be encompassed within the scope of the invention as described herein. The description of the preferred embodiment and of the drawings showing the same are provided herein for illustrative purposes only.
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Wainscot wall panels made at a manufacturing plant through either the cut and assembly of the various components that make up the panel, through routing of a lumber, plywood, or other material, then assembled into a prefabricated wainscot, for later shipment and installation at the home or jobsite during construction or renovation. The panels have three piece construction with a center panel, rails above and below the center panel, and half and full stiles flanking the center panel and perpendicular to the rails. Alternatively, the raised panel, rails, and stiles can be routed or pressed from a single piece of wooden material.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/119,391 filed on 3 Dec. 2008. U.S. Provisional Patent Application No. 61/119,391 is hereby incorporated by reference.
STATEMENT REGARDING FEDERALLY FUNDED RESEARCH
[0002] None.
BACKGROUND
[0003] 1. Technical Field
[0004] This invention relates to a method for cracking high boiling polymers to improve yield and minimize waste in a process for making trichlorosilane (HSiCl 3 ). The polymers include tetrachlorodisiloxane (H 2 Si 2 OCl 4 ), pentachlorodisiloxane (HSi 2 OCl 5 ), hexachlorodisiloxane (Si 2 OCl 6 ), and hexachlorodisilane (Si 2 Cl 6 ). The cracking process produces additional HSiCl 3 and/or tetrachlorosilane (SiCl 4 ) useful in process for producing polycrystalline silicon.
[0005] 2. Problem to be Solved
[0006] SiCl 4 is a by-product produced when silicon is deposited on a substrate in a chemical deposition (CVD) reactor that uses a feed gas stream comprising HSiCl 3 and hydrogen (H 2 ). It is desirable to convert the SiCl 4 back to HSiCl 3 to be used in the feed gas stream. One process for converting SiCl 4 back to HSiCl 3 comprises feeding H 2 and SiCl 4 to a fluidized bed reactor (FBR) having silicon particles therein. The FBR operates at high pressure and temperature where the following reaction occurs.
[0000] 3SiCl 4 +2H 2 +Si 4HSiCl 3
[0007] Partial conversion of the H 2 and SiCl 4 to HSiCl 3 is achieved due to equilibrium limitations. H 2 is separated from the chlorosilanes and is recycled back to the feed. Likewise, unconverted SiCl 4 is distilled from the product HSiCl 3 and is recycled. Product HSiCl 3 may be further distilled to remove impurities.
[0008] Residue is generated in the FBR along with the intended product HSiCl 3 . Residue, which is heavier than SiCl 4 , accumulates in the bottoms from the distillation apparatus. Residue typically comprises polychlorosilanes and/or polychlorosiloxanes exemplified by partially hydrogenated species, including tetrachlorodisiloxane (H 2 Si 2 OCl 4 ) and pentachlorodisiloxane (HSi 2 OCl 5 ); and other high boiling species, including hexachlorodisiloxane (Si 2 OCl 6 ) and hexachlorodisilane (Si 2 Cl 6 ). Residue further comprises silicon particulates, which must periodically be removed. The residue is periodically pumped out and disposed of.
[0009] One approach for converting polychlorosilanes and polychlorosiloxanes has been proposed in which these species are fed back to the FBR for making HSiCl 3 . However, it is thought that this process may not be industrially desirable because of limitations presented by reaction kinetics at typical reactor temperatures unless considerable recycle passes are undertaken. This process is also complicated by the interference of the recycle stream with hydrodynamics in the reactor and the intended HSiCl 3 generating reaction itself.
SUMMARY
[0010] A process for cracking polychlorosilanes and/or polychlorosiloxanes comprises: recycling a clean mixture comprising polychlorosilanes and/or polychlorosiloxanes to a distillation apparatus; thereby producing trichlorosilane, tetrachlorosilane, or a combination thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a process flow diagram showing a process of this invention.
[0000]
Reference Numerals
101
SiCl 4 feed line
111
sump
102
H 2 feed line
113
distillation feed line
103
fluidized bed reactor
115
overheads mixture removal line
105
silicon particle feed line
117
residue removal line
107
crude product line
119
solids removing apparatus
108
dust removing apparatus
121
solids removal line
109
silicon particle recycle line
123
clean mixture line
110
distillation column
DETAILED DESCRIPTION
[0012] A process for cracking polychlorosilanes and/or polychlorosiloxanes is described herein. The process may comprise:
a. producing a mixture comprising a polychlorosilane and/or a polychlorosiloxane; optionally b. removing solids from the mixture to form a clean mixture; c. recycling the clean mixture to a distillation apparatus; thereby producing trichlorosilane, tetrachlorosilane, or a combination thereof.
[0016] FIG. 1 shows a process flow diagram of an exemplary process for preparing HSiCl 3 . SiCl 4 is fed through line 101 , and H 2 is fed through line 102 , into a FBR 103 . Silicon particles are fed into the FBR through line 105 and form a fluidized bed in the FBR 103 . A crude product stream comprising HSiCl 3 , SiCl 4 , silicon solids, and H 2 is drawn off the top of the FBR 103 through line 107 . The silicon solids may be removed with a dust removing apparatus 108 such as a cyclone, and returned to the FBR 103 through line 109 . The resulting effluent mixture is fed to the sump 111 of a distillation column 110 through line 113 .
[0017] The sump 111 of the distillation column 110 may contain a catalyst that facilitates cracking of the polychlorosiloxane and polychlorosilane species. Some catalysts may inherently form in the sump 111 of the distillation column 110 resulting from impurities such as tin, titanium, or aluminum. Examples such catalysts include, but are not limited to, titanium dichloride, titanium trichloride, titanium tetrachloride, tin tetrachloride, tin dichloride, iron chloride, AlCl 3 , and a combination thereof. The amount of such catalyst depends on various factors including how frequently the residue is removed from the distillation apparatus 110 and the level of the catalyst present in the effluent mixture from the FBR 103. Alternatively, a catalyst can be added to the sump 111 . Platinum group metal catalysts such as platinum, palladium, osmium, iridium, or heterogeneous compounds thereof can be used. The platinum group metal catalysts may optionally be supported on substrates such as carbon or alumina. The amount of catalyst may vary depending on the type of catalyst and the factors described above, however, the amount may range from 0 to 20%, alternatively 0 to 10% of the residue. One skilled in the art would recognize that different catalysts have different catalytic activities and would be able to select an appropriate catalyst and amount thereof based on the process conditions in the distillation apparatus 110 and the sump 111 .
[0018] A mixture including SiCl 4 , HSiCl 3 , and H 2 is removed from the top of the distillation column 110 through line 115 . The SiCl 4 and H 2 may be recovered and fed back to the FBR 103 , as described above. The HSiCl 3 may optionally be used as a feed gas for a CVD reactor (not shown) for the production of polycrystalline silicon.
[0019] Residue is generated in the FBR 103 along with the intended product HSiCl 3 . Residue, which is heavier than SiCl 4 , accumulates in the sump 111 . The residue is periodically removed through line 117 . Residue typically comprises a polychlorosilane and/or a polychlorosiloxane. Such polychlorosilanes and polychlorosiloxanes are exemplified by partially hydrogenated species, including tetrachlorodisiloxane (H 2 Si 2 OCl 4 ) and pentachlorodisiloxane (HSi 2 OCl 5 ); and other high boiling species, including hexachlorodisiloxane (Si 2 OCl 6 ) and hexachlorodisilane (Si 2 Cl 6 ). The exact amount of each species of polychlorosilane and polychlorosiloxane in the residue may vary depending on the process chemistry and conditions that produce the residue. However, residue may contain 0 to 15% H 2 Si 2 OCl 4 , 5% to 35% HSi 2 OCl 5 , 15% to 25% Si 2 OCl 6 , and 35% to 75% Si 2 Cl 6 , based on the combined weights of the polychlorosilanes and polychlorosiloxanes in the residue. Residue may further comprise solids, which are insoluble in the species described above. For example, the solids may be polychlorosiloxanes having 4 or more silicon atoms and higher order polychlorosilanes. The solids may further comprise silicon particulates, which may optionally be recovered as described below and optionally recycled to the FBR 103 .
[0020] The residue may be fed to a solids removing apparatus 119 . The solids may be removed through line 121 . The clean mixture (i.e., the mixture comprising tetrachlorodisiloxane, pentachlorodisiloxane, hexachlorodisiloxane, and hexachlorodisilane with the solids removed) may be sent through line 123 back to the sump 111 .
[0021] FIG. 1 is intended to illustrate the invention to one of ordinary skill in the art and should not be interpreted to limit the scope of the invention set forth in the claims. Modifications may be made to FIG. 1 by one of ordinary skill in the art and still embody the invention. For example, one skilled in the art would recognize that cyclone 108 is optional and that one or more of the feeds in lines 101 , 102 , and 105 may optionally be combined before being fed into the FBR 103 . One skilled in the art would recognize that the distillation column 110 can have a different configuration than that shown in FIG. 1 , e.g., a separate reboiler into which gas from line 113 is fed may be used instead of the sump 111 . The residue would then accumulate in the reboiler. Furthermore, an alternative process for producing HSiCl 3 may be used, for example, an alternative FBR 103 that produces HSiCl 3 from HCl and particulate silicon.
[0022] Cracking reactions of the polychlorosilane and/or polychlorosiloxane species in the clean mixture can form monomeric chlorosilane species (HSiCl 3 and SiCl 4 ) and higher order silane and siloxane polymers with each successive reaction of the species in the clean mixture. The siloxane polymers become large enough to form solids at approximately 4 units long. Under the conditions in the distillation apparatus, polychlorosilanes undergo cracking reactions, similarly. The partially hydrogenated species described above exhibit equilibria with HSiCl 3 , and the other (not hydrogenated) species described above, exhibit equilibria with SiCl 4 according to the following reactions:
[0000] H n Si 2 OCl 6-n H n-1 Si 3 O 2 Cl 8-n +HSiCl 3 ,
[0000] where subscript n represents the number of hydrogen atoms, e.g., 1 or 2,
[0000] Si 2 OCl 6 Si 3 O 2 Cl 8 +SiCl 4 .
[0000] When the polychlorosiloxanes reach a degree of polymerization of 4 or greater, a solid may form and the reaction may become irreversible, as illustrated below:
[0000] H n Si 3 O 2 Cl 8-n →H n-1 Si 4 O 3 Cl 10-n (solid)+HSiCl 3 ,
[0000] and
[0000] Si 3 O 2 Cl 8 →Si 4 O 3 Cl 10 (solid)+SiCl 4 .
[0000] Based on the kinetic data, the reactions above all occur at different rates in the sump 111 to permit the above equilibria to be reached within the residence time for the species in the sump 111 when the clean mixture is recycled. The sump 111 may operate at 130° C. to 280° C., alternatively to 180° C. to 240° C., and alternatively 200° C. to 220° C., for a residence time ranging from 10 days to 1 hour at a pressure ranging from 25 bar to 40 bar. One skilled in the art would recognize that the residence time selected depends on various factors including the temperature and the presence or absence of a catalyst. The pressure may be selected based on practical limitations. Increasing pressure will increase the boiling temperatures in the distillation apparatus. The range of pressures enable the reaction to occur at the appropriate temperatures, and therefore at sufficient rate.
INDUSTRIAL APPLICABILITY
[0023] The process described herein reduces waste and improves yield of chlorosilane monomers (HSiCl 3 and SiCl 4 ) useful for the production of polycrystalline silicon. Polychlorosilanes and polychlorosiloxanes that otherwise would have been disposed of as waste are cracked to form useful HSiCl 3 and SiCl 4 .
|
A process for reducing waste and increasing yield of chlorosilane monomers is performed by cracking polychlorosiloxane and polychlorosilane by-products generated during production of trichlorosilane useful for the manufacture of polycrystalline silicon.
| 2
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a division of U.S. patent application Ser. No. 09/574,987 filed May 12, 2000 which in turn is a division of U.S. patent application Ser. No. 09/137,008, filed Aug. 20, 1998 and issued as U.S. Pat. No. 6,143,138 on Nov. 7, 2000.
BACKGROUND OF THE INVENTION
This invention relates generally to a method and apparatus for producing a pH change in a solution. More specifically, the invention relates to producing a pH change in a solution by irradiating the solution with visible light. With greater specificity, but without limitation thereto, the invention relates to using light to alter the pH of a solution to thereby cause an expansion and/or contraction of a pH dependent polymer immersed in the solution.
There exist a number of natural and synthetic fibers and gels that are expandable and contractible in volume when activated by an environmental change, such as exposure to a change in solvent composition, temperature, pH, electric field or photo irradiation, for example. As a commercially exploitable technology, the fibers and gels have applications in many fields, such as, for example, use in sensors, switches, motors, pumps, non-metallic operations and use in the medical and robotic fields where it is envisioned that these materials will be able to carry out the function of human muscle tissue.
The work of W. Kuhn and B. Hargitay as described in “Muskelahnliche Arbeitsleistung Kunstlicher Hochpolymerer Stoffe”, Z. Elektrochemie 1951, 55(6), 490-502, incorporated by reference herein is one example of a synthesized polymer material capable of expansion and/or contraction. When the Kuhn and Hargitay polyacrylamide fiber, known as polyacrylic acid-polyvinyl alcohol (PAA-PVA), is placed within a solution of appropriately increasing pH, a 10% increase in fiber length is claimed to be observed.
Similarly, the work of T. Tanaka, D. Fillmore, S-T. Sun, I. Nishio, G. Swislow, and A. Shah described in the article “Phase Transitions in Ionic Gels” Phys. Rev. Lett. 1980, 45(20), 1636-1639, incorporated by reference herein discloses an observed 400% volume collapse for a polyacrylamide gel disposed in a 50% acetone-water solvent mixture in which the pH of the solvent is lowered at constant temperature and solvent composition.
The work of Kuhn and Hargitay as well as Tanaka and Fillmore et al use a typical approach to changing the pH of a solution. In this approach, the pH is changed by manually dripping an acid or base into the solution. This technique, known as the “acid drip” method, relies upon the rate of the diffusion of hydrogen ions to a polymer site and is considered undesirably slow for certain polymer applications, such as use in synthetic muscles.
Besides the pH activation method of Kuhn and Hargitay and Tanaka and Fillmore et al, there exist electrical polymer activation schemes in which p-electron conjugated conducting polymers and electronically doped non-conducting polymers are electrically activated (expanded and contracted). An example of this activation method has been characterized by Shahinpoor et al as described in the article of D. J. Segalman, W. R. Witkowski, D. B. Adolf, and M. Shahinpoor titled: “Theory and Application of Electrically Controlled Polymeric Gels”, Smart Materials and Structures , Vol. 1 (no. 1), M. V. Gandhi and B. S. Thompson (Eds.), London: Chapman and Hall, 1992, 95-100. Like the pH activation method described above, the Shahinpoor et al method depends on the slow diffusion of ions to the active site of a polymer and therefore is also considered too slow for certain polymer applications such as use in synthetic muscles.
In addition to the activation approaches described above, there exist optical activation methods for causing volume changes in polymer fibers and gels. Noteworthy of these is the work of M. Irie and D. Kunwatchakun described in “Photoresponsive Polymers. 8. Reversible Photostimulated Dilation of Polyacrylamide Gels Having Triphenylmethane Leuco Derivatives”, Macromolecules 1986, 19(10), 2476-2480. The Irie-Kunwatchakun studies were among the earliest on photoinduced volume changes in polymer gels. Photosensitive molecules, such as leucocyanide and leucohydroxide, were incorporated directly into a polymer's network. Irradiation with UV light produced a 2.2-fold reversible dimension change, but no significant volume change (phase transition) took place in the polymer studied, as the UV light-induced pH change was far from the pH null point of the polymer gel. Thus the magnitude of the dimension change was not optimized for certain applications such as robotics.
In the work of researchers Mamada and Tanaka as described in A. Mamada, T. Tanaka, D. Kungwatchakun, and M. Irie in “Photoinduced Phase Transition of Gels”, Macromolecules 1990, 23, 1517-1519 and as described in A. Mamnada, T. Tanaka, D. Kungwatchakun, and M. Irie in U.S. Pat. No. 5,242,491 titled: “Photo-induced Reversible, Discontinuous Volume Changes in Gels” and issued Sep. 7, 1993, photoinduced phase transitions in gels were observed. The copolymer used was that of Irie-Kunwatchakun described above. At a given temperature, the polymer gel discontinuously swelled in response to UV irradiation and shrank when the UV light was removed. It is hypothesized that this swelling is due to dissociation into ion pairs, thereby increasing internal osmotic pressure within the gel. The shrinking process of this method is governed by ion diffusion and recombination, making the speed of the reverse process impossible to control, thereby hindering its usefulness in many polymer actuator applications.
In either of the UV studies described above, the UV radiation can cause undesired ionization, photolysis and molecular ligation of a utilized polymer.
Finally, in the work of A. Suzuki and T. Tanaka described in the article “Phase Transition in Polymer Gels Induced by Visible Light”, Lett. Nature 1990, 346, 345-347, visible light was used to irradiate a gel containing a light-sensitive chromophore located in the backbone of an expandable and contractible copolymer. The chromophore absorbed the light and the light energy was then dissipated locally as heat by radiationless transitions, the result of which increased the “local” temperature of the polymer. Unlike the UV studies, the polymer expansion is a rapid process and is due to the direct heating of the polymer network by light. Yet the process of returning the polymer to its original size requires cooling, which becomes increasingly difficult as the temperature of the surrounding solution approaches the temperature of the polymer. This reverse process is too slow for many polymer uses such as in synthetic muscles.
Because many reactions are based on either acid or base catalyzations, including those of the polymers described above, researchers have investigated various approaches to promoting rapid pH changes. Such has been the case of Anthony Campillo et al as described in the article by A. J. Campillo, J. H. Clark, R. C. Hyer, S. L. Shapiro, K. R. Winn, and P. K. Woodbridge titled: “The Laser pH Jump”, Proc. Intl. Conf. Lasers '78, Orlando, Fla., Dec. 11-15, 1978, Chem. Phys. Lett. 1979, 67(2), 218-222; the article by A. J. Campillo, J. H. Clark, S. L. Shapiro, K. R. Winn, and P. K. Woodbridge, titled: “Excited-State Protonation Kinetics of Coumarin 102”, Chem. Phys. Lett. 1979, 67(2), 218-222; the article by J. H. Clark, S. L. Shapiro, A. J. Campillo, K. R. Winn, titled: “Picosecond Studies of Excited-State Protonation and Deprotonation Kinetics. The Laser pH Jump”, J. Am. Chem. Soc. 1979, 101(3), 746-748; and U.S. Pat. No. 4,287,035 issued to John H. Clark, Anthony J. Campillo, Stanley L. Shapiro, and Kenneth R. Winn on Sep. 1, 1981.
The work of Campillo et al relies on excited-state proton transfer reactions to change the [H + ] of a solution by several orders of magnitude. Campillo et al used a picosecond spectroscopy tool to directly measure excited-state deprotonation-protonation reaction rate constants. To promote a pH change, a UV laser with a pulse width of 20 picoseconds was used to excite 2-naphthol-6-sulfonate to a higher (S 1 ) electronic state. From the measured rate constants, Campillo et al determined that the excited-state pK a value was 1.9, as opposed to the ground-state value of 9.1. This 7-unit change in pK a corresponds to a 7-order of magnitude increase in the acid dissociation constant, K a . Campillo's findings are consistent with earlier studies which show that excited-state K a values can differ from ground-state values by many orders of magnitude, see the disclosure of J. F. Ireland and P. A. H. Wyatt titled: “Acid-Base Properties of Electronically Excited States of Organic Molecules”, Adv. Phys. Org. Chem. 1976, 12, 131-221.
Campillo et al claim that a major use of their technique is initiation of acid-base catalyzed ground-state reactions. For example, the reactants A and B are present in solution at pH 7. The ground state reaction, A+B→C, occurs only at pH 4. By exciting the Campillo et al “jump molecule”, 2-naphthol-6-sulfonate, a subnanosecond jump from pH 7 to pH 4 can be achieved, thereby enabling the desired ground-state reaction. Referring to FIG. 1, a schematic state energy level diagram illustrates the path by which the “jump molecule” 2-naphthol-&sulfonate travels to produce the pH change described. The 2-naphthol-6-sulfonate is irradiated with LTV light and is excited from ground state S 0 to first excited singlet state S 1 . Radiative decay (florescence) then occurs bringing the molecule back to its ground state.
A major drawback of the Campillo technique is the extremely short duration of the accompanying pH change, typically 10 nanoseconds. While Campillo proposes that the excited state duration, and hence pH change, could be prolonged through use of repetitious irradiation, such an irradiation would require a bombardment of photons on the order of a million times a second. An additional shortcoming of the Campillo technique, when utilized with expandable and contractible polymers such as those described above, is that the utilized UV radiation promotes undesirable polymer ionization, photolysis and other molecular ligation. Additionally, the extremely narrow illumination path (0.1 mm or 5D-6 cubic centimeters) provided by the utilized 266 nanometer laser is considered insufficient to effectively illuminate an expandable/contractible polymer to undergo an appreciable change in volume.
SUMMARY OF THE INVENTION
The invention provides a method and apparatus of rapidly changing the pH of a solution by way of a pH jump molecule that is activated by visible light. An application of the present invention is the ground-state reaction of changing the volume of an expandable and contractible polymer for simulated muscle applications as well as for other applications.
To permit these applications, it is desirable (1) to use a source of excitation energy that is not harmful to a utilized polymer; (2) to produce an in-situ pH change in which hydrogen ions become rapidly present at a polymer site; (3) to sustain the resultant pH change long enough and in a volume large enough for desired ground-state reactions to occur, for example, the fully reversible expansion and contraction of a polymer; and (4) to provide a mechanism for efficient dissipation of heat produced as a result of the source of excitation energy.
Candidate pH “jump molecules” considered suitable for providing sufficient polymer actuation (activation) should possess the following characteristics:
(1) the jump molecules should have long lifetimes at room temperature, e.g 10 milliseconds;
(2) the jump molecule acidity constants should be grossly different in ground and triplet states, e.g., 7 orders of magnitude;
(3) the resultant pH change should go through the midpoint (pH null point) of the utilized polymer; and
(4) either the non-protonated or the protonated form of the jump molecule should absorb in the visible region of the spectrum.
In accordance with the present invention, an apparatus and method incorporating these desirable features are disclosed. The invention includes a pH jump molecule that permits visible light excitation to provide a long lasting pH change to a pH dependent polymer or other pH driven reactant. The attendant pH change occurs rapidly (in nanoseconds) and will last for the excited state lifetime of the jump molecule. Further irradiation by either a continuous wave or appropriately pulsed laser can sustain the pH change indefinitely. The pH jump molecule is phosphorescence. That is, heat resulting from the light activation is efficiently discharged by radiative decay through room temperature phosphorescence lifetimes existing on the order of milliseconds. Thus an expandable and contractible polymer can be made to respond rapidly to a change in pH while the radiant heat-release mechanism of the invention allows the polymer to return to its initial configuration in a millisecond time frame, suitable for a variety of useful applications, including robotics.
Accordingly, it is an object of this invention to provide a method and apparatus for producing a rapid pH change in a solution.
A further object of this invention is to produce a rapid pH change in a solution that is useful in causing the expansion and/or contraction of a polymer.
Another object of this invention is to produce a rapid pH change in a solution that lasts long enough and is prevalent enough to be useful in causing the expansion and/or contraction of a polymer.
Still another object of this invention is to produce a rapid pH change in a solution that is useful in causing the expansion and/or contraction of a polymer while minimizing damage to the polymer.
Still yet another object of this invention is to produce a rapid pH change a solution by irradiating the solution with visible light.
Yet another object of this invention is to produce a pH change in a solution by irradiating the solution with visible light in which any heat produced by the light is rapidly dissipated.
Other objects, advantages and new features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic state energy level diagram.
FIG. 2 is illustrates the pH expansion and contraction dependence of an exemplary polymer, in this case an acrylamide gel.
FIG. 3 describes ΔpK values for various families of molecules
FIG. 4 illustrates the light absorbance of anthracene versus wavelength.
FIG. 5 illustrates the pH expansion and contraction dependence of another exemplary polymer, in this case a polyacrylic acid-polyvinylalcohol (PAA-PVA) fiber.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the expandable and contractible polymer world, a term of art has evolved that describes the large and easily perceptible change in volume that occurs when such a polymer, whether it be a gel or a fiber, is exposed to a particular change in the pH of a solution in which the polymer is immersed. This term of art is known as a “phase transition”, and describes the physical phenomenon that takes place when the polymer is exposed to a narrow change in pH that passes through what is know as the pH null point of the polymer.
Referring to FIG. 2, there is shown a graphical depiction of such a phase transition. This illustration, taken from the 1980 Physical Review Letter of T. Tanaka and D. Fillmore et al referred to above, shows the response of a polymer network of an acrylamide gel that has been hydrologized in a 4% (volume) N,N,N,N-tetramethylenediamine (TEMED) solution. The quantity φ/φ* represents the swelling ratio which is the ratio of the final polymer network concentration to the initial polymer network concentration. The smooth curve is for gels immersed in water. The discontinuous curve is for gels in a 50% acetone-water mixture. In either case, as pH is increased, the gel swells; as the pH is decreased, the gel shrinks.
For the acetone-water mixture shown in FIG. 2, the sharp s-shaped curve is characteristic of a phase transition. This behavior is referred to as a phase transition because an enormous amount of polymer swelling-shrinking occurs within a very narrow range of pH values. Capitalizing on this phenomenon, the greatest leverage for polymer activation can be achieved by finding a polymer-polymer activation system that has a PK a at the midpoint of the pH curve (or what is otherwise referred to as the null point of the polymer). The closer that the ground state pK a of a candidate “jump molecule” is to the null point of a polymer, the greater will be the variability of polymer volume for a given quantity of excitation energy. By using such a jump molecule, a small change in pH to either side of the midpoint will expand or contract the polymer by the largest amount possible, optimizing polymer dimensional change for use in robotics or other applications.
The term pK is a shorthand indicating the strength of an acid (pK a ) and is defined as the −log 10 K in which K is the characteristic equilibrium constant K, represented by:
K=[H + ][B]/[BH + ]
where [H + ] is the hydrogen ion concentration and [B] is the concentration of the conjugate base. When the amount of one of these constituents is varied, the others will adjust to keep K constant.
During the course of scientific research, the inventor constructed kinetic equations for the 3-level system of FIG. 1 . Referring again to FIG. 1, an ideal “jump molecule” will be excited from ground state energy level (S 0 ) to first excited singlet state energy level (S 1 ), and return to the ground state via triplet state energy level (T 1 ). The radiationless transition and radiative decay via phosphorescence will function as a “sink” for the molecules and because of their combined long lifetime, a prolonged molecule excited state will exist. The pH change produced by this excitation will last for the life of this excited state.
Repeated runs with many different candidate jump molecules predicted the requirements necessary to sustain a desired pH change:
(1) jump molecules should have long excited state lifetimes at room temperature, e.g., 10 milliseconds;
(2) jump molecule acidity constants must be grossly different in the triplet and ground states, e.g., 7 orders of magnitude;
(3) the resultant pH change should go through the midpoint (pH null point) of a utilized polymer; and
(4) either the non-protonated or the protonated form of the jump molecule should absorb in the visible region of the spectrum.
A great many molecules with functional groups were eliminated based upon being disqualified by the above requirements.
For example, the phenones are considered undesirable because the lifetimes of the protonated and non-protonated forms are very different, providing a rapid excited state deactivation channel. An example of this is benzophenone, having an unprotonated lifetime of 100 milliseconds and a protonated lifetime of 62 nanoseconds.
In addition, a great many functional groups were eliminated based upon small ΔpK values, ΔpK in this instance being the difference between first triplet state pK value minus the ground state pK value (pK(T 1 )−pK(S 0 )), as can be seen in FIG. 3 .
In Table 1, characteristics of the carbon acids are described. The carbon acids shown exhibited long excited-state lifetimes τ p (p for phosphorescence), large ΔpK values, and have ΔpK values that pass through a desired polymer null point, however the excitation wavelength λ 00 necessary to initiate a pH change falls within the ultraviolet. In this table, “obs” means “observed” and “c” means “calculated”.
TABLE 1
τ p
pK
pK
pK
λ 00
(msec)
(S 0 )
(S 1 )
(T 1 )
(nm)
fluorene
0.35
23.04
−5.96 (c)
7.54 (c)
300
9-phenylflourene
obs
18.6
−10.7 (c)
4.2 (c)
305
9-cyanflourene
obs
11.4
−12.4 (c)
5.0 (c)
300
Through the process of elimination, several families of molecules satisfied the pH jump molecule requirements stated above. One of these are the polynuclear aromatic hydrocarbons (PAC's) which are bases.
Of these, the PAC, anthracene, fits well with certain well established polymers. Referring to FIG. 4, the protonated form of this molecule is confirmed. In FIG. 4, an absorbance versus wavelength profile shows the zero-time spectrum for protonated anthracene. The peak at 424 nm is the only peak within the visible region of the spectrum which decreases with time, and is the signature of anthracene's protonated form. It is this peak that is used to activate the anthracene polymeric actuator with visible light.
Referring to FIG. 5, the contractile-expansion characteristics of the Kuhn-Hargitay polyacrylic-acid-polyvinylalcohol (PAA-PVA) polymer are shown. The Kuhn-Hargitay polymer fiber undergoes a phase transition between pH levels of 5 and 5.5, having a pH null point of approximately 5.3, as shown by the “Lange des Fadens” or “Length of Fiber” solid line.
Referring now to Table 2, specifications for utilizing protonated anthracene in coordination with the polymer described by Kuhn-Hargitay referred to above are shown.
TABLE 2
pH change and species concentrations
BH+ only absorbing, pH = 5.0, 413.1 nm
BH+ <--> B + H+
Anthracene Jump Molecule
Lamda = 413.1 nm
Log
Ground
Singlet
Triplet
(eps)
epsilon
pK's
3.8
13.6
10.3
Lifetimes nS (mS)
10.0
(10.0)
B
9.7D-4
1.5D-21
3.0D-11
0.04
1
BH+
6.4D-4
2.0D-11
2.0D-4
4.38
23988
Initial Concentrations:
Final pH:
pH
5.0
5.48
[H+]
1.0D-5
3.3D-6
[B]
9.8D-4
[BH+]
2.0D-4
Watts
4.2
Photons/sec
9.3D + 18
Total B
1.0D-3
V cm3
1.0
P/cm3-sec
9.3D + 18
413.1 nm = Center Kr+ line: 406.7, 413.1, 415.4
By utilizing visible light, the protonated form BH + of anthracene is disassociated into its base (B) and hydrogen ion (H + ) constituents to prompt a pH change from 5 to 5.48. As can be seen, the ΔpK (pK(T 1 )−pK(S 0 )) of anthracene is 10.3-3.8, permitting such a large scale pH change. The calculation in Table 2 is based on a pK(S 0 ) value for anthracene found in Mackor. E. L., Hofstra, A., and Van Der Waals, J. H., 1958, in an article entitled “The Basicity of Aromatic Hydrocarbons”, Trans. Faraday Soc., vol. 54, 66.
For use with the referenced Kuhn-Hargitay polymer, the desired protonated form of anthracene is derived by dissolving enough anthracene in cyclohexane, as described in Table 2, so that the resulting concentration of non-protonatedanthracene is 9.8D-4 moles/liter when the pH is adjusted to 5.0 by the addition of sulfric acid (H 2 SO 4 . The mixture is then vigorously shaken in a separatory funnel, causing the anthracene to diffuse from the cyclohexane to the sulfuric acid to form a solution of protonated anthracene.
For the polymer-anthracene combination described, a BeamLok 2080 krypton ion laser was used to irradiate the polymer system at 413.1 nanometers and 4.2 watts. The one cubic centimeter irradiation volume is large enough to house a polymer of macroscopic dimensions as the jump molecule provides a pH change from 5.0 to 5.48. Because of the 10 millisecond prolonged excited state of the anthracene jump molecules, the continuous wave laser will permit constant pH elevation until the irradiation is cut-off, at which time the excited-state jump molecules will decay to the ground state and reassociate, causing a return to the original pH in a few milliseconds. Importantly, the heat created by the molecules absorbing the irradiated light is released as light of a longer wavelength. Full polymer reversibility, which is not hindered by the slow dissipation of heat, is therefore made possible for use in many polymer applications, including robotics.
Besides use of a continuous wave irradiation source, a pulsed laser having a repetition rate of 100 times a second at 42 millijoules will also suffice. This repetition rate will prompt a pulse every 10 milliseconds, permitting continuous pH elevation.
Referring now to Table 3, specifications for utilizing protonated anthracene in coordination with the polymer described by Tanaka-Fillmore et al referred to above are shown. The protonated form BH + of anthracene coordinates well with the Tanaka polymer in which the null point of this polymer (3.8 pH) corresponds with the ground state pKa value of the anthracene.
TABLE 3
pH change and species concentrations
BH+ only absorbing, pH = 3.7, 413.1 nm
BH+ <--> B + H+
Anthracene Jump Molecule
Lamda = 413.1 nm
Log
Ground
Singlet
Triplet
(eps)
epsilon
pK's
3.8
13.6
10.3
Lifetimes nS (mS)
10.0
(10.0)
B
6.4D-4
3.2D-21
6.9D-11
0.04
1
BH+
1.8D-4
2.3D-11
1.8D-4
4.38
23988
Initial Concentrations:
Final pH:
pH
3.7
3.9
[H+]
2.0D-4
1.3D-4
[B]
7.1D-4
[BH+]
2.9D-4
Watts
6.3
Photons/sec
1.4D + 19
Total B
1.0D-3
V cm3
1.0
P/cm3-sec
1.4D + 19
413.1 nm = Center Kr+ line: 406.7, 413.1, 415.4
For use with the Tanaka-Fillmore polymer, the desired protonated form of anthracene is derived by dissolving enough anthracene in cyclohexane, as described in Table 3, so that the resulting concentration of non-protonated anthracene is 7.1D-4 moles/liter when the pH is adjusted to 3.7 by the addition of sulfuric acid (H 2 SO 4 ). The mixture is then vigorously shaken in a separatory funnel, causing the anthracene to diffuse from the cyclohexane to the sulfuric acid to form a solution of protonated anthracene.
For the polymer-anthracene combination described, a BeamLok 2080 krypton ion laser may be used to irradiate the polymer system at 413.1 nanometers and 6.3 watts. The one cubic centimeter irradiation volume is large enough to house a polymer of macroscopic dimensions as the jump molecule provides a pH change from 3.7 to 3.9. The 10 millisecond prolonged excited state, permits the continuous wave laser to maintain a constant elevated pH level. Once the irradiation is cut-off, the excited-state jump molecules will decay to the ground state and reassociate, causing a return to the original pH in a few milliseconds. As before stated, the heat created by the jump molecules absorbing light will be efficiently discharged as light of a longer wavelength.
Obviously, many modifications and variations of the invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as has been described.
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A method and apparatus for initiating a rapid and long-lasting pH change to a pH dependent polymer or other pH driven reactant is provided by a pH jump molecule in solution. Visible light is used to excite the pH jump molecule. The attendant pH change occurs rapidly (in nanoseconds) and can be maintained by continuous wave light or by an appropriately pulsed light. Heat resulting from the light activation is efficiently discharged by radiative decay through room temperature phosphorescence lifetimes existing on the order of milliseconds.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation application of U.S. patent application Ser. No. 09/260,621, entitled “Automated Integration of Terminological Information into a Knowledge Base”, filed on Mar. 1, 1999 now U.S. Pat No. 6,654,731.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed toward the field of knowledge bases for use in natural language processing systems, and more particularly toward integrating thesauri from disparate sources into a single knowledge base.
2. Art Background
In general, knowledge bases include information arranged to reflect ideas, concepts, or rules regarding a particular problem set. Knowledge bases have application for use in natural language processing systems (a.k.a. artificial linguistic or computational linguistic systems). These types of knowledge bases store information about language. Specifically, natural language processing knowledge bases store information about language, including how terminology relates to other terminology in that language. For example, such a knowledge base may store information that the term “buildings” is related to the term “architecture,” because there is a linguistic connection between these two terms.
Natural language processing systems use knowledge bases for a number of applications. For example, natural language processing systems use knowledge bases of terminology to classify information. One example of such a natural language processing system is described in U.S. Pat. No. 5,694,523, entitled “Content Processing System for Discourse,” issued to Kelly Wical on Dec. 2, 1997, which is expressly incorporated herein by reference. Terminological knowledge bases also have application for use in information search and retrieval systems. In this application, a knowledge base may be used to identify terms related to the query terms input by a user. One example for use of a knowledge base in an information search and retrieval system is described in U.S. patent application Ser. No. 09/095,515, entitled “Hierarchical Query Feedback in an Informative Retrieval System,” by Mohammad Faisal, filed on Jun. 10, 1998 and U.S. patent application Ser. No. 09/170,894, entitled “Ranking of Query Feedback Terms in an Information Retrieval System,” by Mohammad Faisal and James Conklin, filed on Oct. 13, 1998, both of which are incorporated herein by reference.
Natural language processing systems, including information search and retrieval systems, may be applied to domain specific applications. For example, a natural language processing system may process and classify information (e.g., documents) about medicine for a system tailored for the medical profession. For this example, a natural language processing system may compile and classify thousands of documents related to medicine. A commercially available natural language processing system may include a general knowledge base, that includes terminology from a wide range of topics. However, this general knowledge base may not include specific terminology relating to a domain specific application. A user of the natural language processing system for the medical application may desire to augment the general knowledge base with terms specific to medicine. For example, the user may desire to augment the knowledge base to include terms that classify specific types of blood disorders. As illustrated by the above example, it would be impossible for a commercial developer of a knowledge base to thoroughly include all topics or domains of interest to all users. Accordingly, it is desirable to provide a means for a user to add domain or topic specific terminological information into a built-in knowledge base. It is also desirable to provide an automated means to enter the terminological information to facilitate easy use of a system, as well as provide a seamless integration of domain specific terms and a general built-in knowledge base.
SUMMARY OF THE INVENTION
A terminological system automates the integration of terminological information into a knowledge base. The system contains a built-in knowledge base comprising a plurality of nodes, which represent terminology, arranged to depict relationships among the terminology. Input terminology information, which includes a plurality of input terms and information that specifies relationships among at least two of the input terms, is input to the terminological system. The terminological system parses the input terminology information to generate a logical structure that depicts relationships among the input terms in a format compatible with the built-in knowledge base. A determination as to whether at least one input term exists as a node in the knowledge base is made, and if there is no corresponding node, then an independent ontology comprising the logical structure is generated. If at least one input term exists as a node in the knowledge base, then the knowledge base is extended by logically coupling the logical structure to a node that matches the input term. The terminological system also resolves conflicts if an input term that matches a terminological node in the knowledge base connotes a different meaning than the terminological node.
In one embodiment, the input terminology information is received in an ISO 2788 format. For this embodiment, the input terminology information may include broader term and narrower term relationships among two input terms for conversion to parent-child and child-parent relationships in the built-in knowledge base. The input terminology information may also include synonym relationships between two terms for conversion to parent-child relationships between a common parent node in the knowledge base and the input terms specified as synonym relationships. Furthermore, the input terminology information may include related term (RT) relationships among at least two input terms for conversion to cross references between terms comprising a related term (RT) relationship in the input terminological information. In addition, the input terminology information may include preferred term (PT) relationships among at least two input terms for conversion to a canonical/alternate form index between terms comprising a preferred term (PT) relationship in the input terminological information.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating one embodiment for a system that automates integration of terminological information into a knowledge base.
FIG. 2 illustrates an example portion of a knowledge base augmented to include additional terminology as well as cross references and links among categories and terms.
FIG. 3 is a flow diagram illustrating one embodiment for the thesaurus compiler of the present invention.
FIG. 4 is a flow diagram illustrating one embodiment for mapping an ISO-2788 entry to a knowledge base.
FIG. 5 is a flow diagram illustrating one embodiment for building a logical structure for hierarchical relations and cross-references.
FIG. 6 a illustrates a logical structure for the terminological information of Table 3 configured in accordance with one embodiment.
FIG. 6 b illustrates a hierarchical structure for the example input terminological information of Table 4.
FIG. 6 c illustrates an example portion of an ontology for the parent category “macro economic measures” for the built-in knowledge base example.
FIG. 6 d illustrates one example of modifying the built-in knowledge base of FIG. 6 c to avoid conflict with the input terminological information of Table 4 and FIG. 6 b.
FIG. 7 is a flow diagram illustrating one embodiment for resolving conflicts among one or more terms of the input terminological information with terms of the built-in knowledge base.
FIG. 8 is a block diagram illustrating one embodiment for a natural language processing system incorporating the integrated knowledge base of the present invention.
FIG. 9 illustrates a high level block diagram of a general purpose computer system in which the natural language processing system and thesaurus compiler of the present invention may be implemented.
DETAILED DESCRIPTION
FIG. 1 is a block diagram illustrating one embodiment for a system that automates integration of terminological information into a knowledge base. For this embodiment, a terminological system 100 receives, as input, input terminological information 110 , and generates, as output, thesaurus output 180 . In general, input terminological information 110 comprises multiple terms, as well as information that relates at least two terms. For example, input terminological information may include the terms “hepatitis” and “blood diseases”, and the information that “blood diseases” is a broader term than the term “hepatitis.” In one embodiment, input terminological information 110 conforms to the International Standards Organization (ISO) 2788 for generating thesaurus standardized data. A discussion of the ISO-2788 thesaurus is discussed more fully below.
In general, the thesaurus output 180 comprises a plurality of files for use as a specialized knowledge base in a natural language processing system (See FIG. 8 ). The content of thesaurus output 180 is described more fully below. The engine for the terminological system 100 comprises a thesaurus compiler 130 . The thesaurus compiler 130 processes the input terminological information, and through use of morphological information, generates the thesaurus output 180 . In general, the thesaurus output 180 comprises a knowledge base that includes the built-in knowledge base (e.g., knowledge base 155 ), as well as terminology set forth in the input terminological information 110 . In one embodiment, thesaurus compiler 130 operates in conjunction with normalization processing 120 . If used, normalization processing 120 generates alternate forms of the terms set forth in input terminological information 110 . In general, in nominalization processing, given a term, the goal is to analyze and manipulate its language dependent features until a language independent ontological representation is found.
For the embodiment of FIG. 1 , the morphological section includes a knowledge base 155 , a lexicon 160 , as well as a plurality of indices (i.e., canonical/alternate form index 140 and phrase list 170 ). The knowledge base 155 , illustrated as the system built-in knowledge base, includes a plurality of terms, as well as information on how certain terms relate to other terms.
In general, the knowledge base 155 is the repository for an knowledge about languages and about the concrete and abstract worlds described by language in human discourse. The knowledge base 155 contains two major types of data: language specific data necessary to describe a language used for human discourse, and language independent data necessary to describe the meaning of human discourse. One embodiment for the knowledge base 155 is described more fully below in the section “Knowledge Base.”
The lexicon 160 stores a plurality of terms and phrases, including information about those words. In one embodiment, lexicon 160 contains definitional characteristics for each word. For example, one definitional characteristic defines the part of speech for the corresponding word, such as whether the word is a common noun. Lexicon 160 also identifies the amount of content carrying information for a corresponding word. One embodiment for a lexicon is described in U.S. Pat. No. 5,694,523, issued to Kathy Wical on Dec. 2, 1997, in Appendix A, entitled “Lexicon Documentation.” U.S. Pat. No. 5,694,523, including all of the Appendices, is expressly incorporated herein by reference.
The canonical/alternate form index 140 provides a mapping between a preferred or canonical form of a word, and one or more alternate forms of the word. For example, the term “physician” may be the preferred term for the word “doctors”, when in a medical context. Phrase list 170 lists a plurality of phrases in their preferred form. For example, a canonical form of the phrase “personal computers” may be “PC.” For this example, the index identifies that the preferred term to use for “personal computers” is the term “PC.”
In one embodiment, input terminological information 110 is formatted in compliance with the ISO-2788. For this embodiment, user extensions to the knowledge base 155 are in the form of the ISO-2788 thesaurus. Terms in the input terminological information 110 may have single or multiple words with punctuation if necessary. The maximum length of a term is eighty characters. Per the ISO-2788 standard, terms may be related to one another in any one of the following standard relations: broader term (BT); narrower term (NT); related term (RT); top term (TT); preferred term (PT), and synonym (SYN). In one embodiment, the terminological system 100 processes broader term generic (BTG) and broader term partitive (BPT) as the same as broader term (BT). Similarly, the relations narrower term generic (NTG) and narrower term partitive (NPT) are interpreted as the same as the relation narrower term (NT).
Broader term (BT) and narrower term (NT) relations describe a hierarchical relationship such that the terms are related in a category/subcategory relationship. For example, the term “political geography” is a narrower term (NT) than the broader term “geography.” A related term relation defines terms that do not have a hierarchical relationship (i.e., broader or narrower term relation), but nevertheless the terms have a semantic or usage association. For example, the term “Eiffel Tower” may have a related term relationship with the term “Paris.” A top term (TT) relation describes a term that is the highest or broadest level term in a hierarchical relationship with other terms. The preferred term (PT) relation specifies that a preferred term is to be used instead of the identified alternate form. The synonym (SYN) relation defines that the two terms identified are synonyms, and thus should have sibling relationships in a hierarchical organization of terms (i.e., the term should reside in the same level of a hierarchical structure).
Knowledge Base:
The knowledge base 155 consists of general categories (also referred to herein as leaf nodes), concepts, and cross-references (i.e., Xrefs). Concepts, or detailed categories, are a subset of the canonical forms determined by the language dependent data. These concepts themselves are language independent. In different languages their text representations may be different; however, these terms represent the universal ontological location. Concepts are typically thought of as identification numbers that have potentially different representations in different languages. These representations are the particular canonical forms in those languages. General categories are themselves concepts, and have canonical form representations in each language. These categories have the additional property that other concepts and general categories can be associated with them to create a knowledge hierarchy. Cross references are links between general categories. These links augment the ancestry links that are generated by the associations that form a directed graph.
The ontology in the knowledge base 155 contains only canonical nouns and noun phrases, and it is the normalization processing 120 ( FIG. 1 ) that provides mappings from non-nouns and non-canonical nouns. The organization of the knowledge base 155 provides a world view of knowledge, and therefore the ontology actually contains only ideas of canonical nouns and noun phrases. The text representation of those ideas is different in each language, but the ontological location of the ideas in the knowledge base 155 remains the same for all languages.
The organizational part of the knowledge base 155 is the structured category hierarchy comprised at the top level of general categories. These categories represent knowledge about how the world is organized. The hierarchy of general categories is a standard tree structure. In one embodiment, a depth limit of sixteen levels is maintained. The tree organization provides a comprehensive structure that permits augmentation of more detailed information. The tree structure results in a broad but shallow structure. The average depth from tree top to a leaf node is five, and the average number of children for non-leaf nodes is 4.5.
In the knowledge base 155 , the tree structure is arranged in a plurality of independent ontologies (i.e., each ontology comprises an independent tree structure). In one embodiment, the knowledge base 155 contains six independent ontologies. For purpose of nomenclature, the categories in each tree structure are defined as leaf node categories. Terminology associated with a leaf node category are defined as “concepts.” Typically, a concept provides less topic orientation than a leaf node category.
There are two types of general categories: concrete and abstract. This distinction is an organizational one only and it has no functional ramifications. A concrete category is one that represents a real-world industry, field of study, place, technology or physical entity. The following are examples of concrete categories: “chemistry”, “computer industry”, “social identities”, “Alabama”, and “Cinema.” An abstract category is one that represents a relationship, quality, fielding or measure that does not have an obvious physical real-world manifestation. The following examples are abstract categories: “downward motion”, “stability”, “stupidity, foolishness, fools”, “mediation, pacification”, “texture”, and “shortness.”
Many language dependent canonical forms that map to the language independent concepts are stored as the knowledge base 155 . Each concept is any idea found in the real world that can be classified or categorized as being closely associated with one and only one knowledge base 155 general category. Similarly, any canonical form in a particular language can map to one and only one concept. For example, there is a universal concept for the birds called “cranes” in English, and a universal concept for the machines called “cranes” in English. However, the canonical form “cranes” does not map to either concept in English due to its ambiguity. In another language, which may have two different canonical forms for these concepts, mapping may not be a problem. Similarly, if “cranes” is an unambiguous canonical form in another language, then no ambiguity is presented in mapping.
Cross references are mappings between general categories that are not directly ancestrally related, but that are close to each other ontologically. Direct ancestral relationship means parent-child, grandparent-grandchild, great grandparent-great grandchild, etc. Cross references reflect a real-world relationship or common association between the two general categories involved. These relationships can usually be expressed by universal or majority quantification over one category. Examples of valid cross references and the relationships are shown in Table 1.
TABLE 1 oceans --> fish (all oceans have fish) belief systems --> moral states (all belief systems address moral states) electronics --> physics (all electronics deals with physics) death and burial --> medical problems (most cases of death and burial are caused by medical problems)
Cross references are not automatically bidirectional. For example, in the first entry of Table 1, although oceans are associated with fish, because all oceans have fish, the converse may not be true since not all fish live in oceans. The names for the general categories are chosen such that the cross references that involve those general categories are valid with the name or label choices. For example, if there is a word for fresh water fish in one language that is different than the word for saltwater fish, the oceans to fish cross reference is not valid if the wrong translation of fish is used. Although the knowledge base 155 is described as cross linking general categories, concepts may also be linked without deviating from the spirit and scope of the invention.
FIG. 2 illustrates an example portion of a knowledge base augmented to include additional terminology as well as cross references and links among categories and terms. The classification hierarchy and notations shown in FIG. 2 illustrate an example that classifies a document on travel or tourism, and more specifically on traveling to France and visiting museums and places of interest. As shown in FIG. 2 , the classification categories (e.g., knowledge base 155 ) contains two independent static ontologies, one ontology for “geography”, and a second ontology for “leisure and recreation.” The “geography” ontology includes categories for “political geography”, “Europe”, “Western Europe”, and “France.” The categories “arts and entertainment” and “tourism” are arranged under the high level category “leisure and recreation.”The “visual arts” and the “art galleries and museums” are subcategories under the “arts and entertainment” category, and the category “places of interest” is a subcategory under the category “tourism.”
The knowledge base 155 is augmented to include linking and cross referencing among categories for which a linguistic, semantic, or usage association has been identified. For the example illustrated in FIG. 2 , the categories “France”, “art galleries and museums”, and “places of interest” are cross referenced and/or linked as indicated by the circles, which encompass the category names, as well as the lines and arrows. This linking and/or cross referencing indicates that the categories “art galleries and museums” and “places of interest” may appear in the context of “France.”
For this example, the knowledge base 155 indicates that the Louvre, a proper noun, is classified under the category “art galleries and museums”, and further associates the term “Louvre” to the category “France.” Similarly, the knowledge base 155 indicates that the term “Eiffel Tower” is classified under the category “places of interest”, and is also associated with the category “France.”
The knowledge base 155 may be characterized, in part, as a directed graph. The directed graph provides information about the linguistic, semantic, or usage relationships among categories, concepts and terminology. The “links” or “cross references” on the directed graph, which indicate the associations, is graphically depicted in FIG. 2 using lines and arrows. For the example shown in FIG. 2 , the directed graph indicates that there is a linguistic, semantic, or usage association among the concepts “France”, “art galleries and museums”, and “places of interest.”
Terminological System Embodiments:
In one embodiment, the terminological system 100 ( FIG. 1 ) provides a mapping among relations in the input terminological information 110 , stored as ISO-2788, and relations as stored in a knowledge base 155 . Table 2 includes two columns to show a mapping from the ISO-2788 and the knowledge base embodiment described above. As shown in Table 2, the mapping provides a one to one correspondence between relations defined by the ISO-2788 standard and the relations defined by the knowledge base 155 embodiment.
TABLE 2
ISO-2788
Knowledge Base
BT
parent category
NT
child category
SYN
sibling with a common
parent category
RT
cross reference (Xref),
both directions
PT
canonical form
FIG. 3 is a flow diagram illustrating one embodiment for the thesaurus compiler of the present invention. If a term in the input terminological information 110 is a new term, then an identification (ID) is assigned (blocks 310 and 315 , FIG. 3 ). If the term is a phrase, then the phrase is split and the first term of the phrase is extracted from the knowledge base 155 (blocks 320 , 325 , and 330 ). The phrase is augmented with a new term, and the augmented knowledge base and the entire entry for the term is added to the thesaurus output 180 so as to override the entry in the knowledge base (blocks 335 and 340 ). If the input term is not a new term, then the term is copied into the thesaurus output 180 (blocks 310 and 345 , FIG. 3 ). Alternate form/canonical form relations are generated for the term for storage in canonical/alternate form index 140 (block 350 ). Lexicon flags (e.g., definitional characteristics) are added for input terms currently existing in the knowledge base 155 (block 355 ). For this embodiment, no information regarding definitional characteristics are included for new terms.
Logical structures are built to depict broader term and narrower term hierarchical relations (block 360 , FIG. 3 ). For new phrases, the second word in the phrase information for each new phrase in the thesaurus output is re-computed (block 370 ). For all second words that exist in the knowledge base 155 , their entries are copied to the thesaurus output 180 if their status changes (i.e., a word that did not have this characteristic set is now flagged because it occurs in the second position in the new phrase). In one embodiment, the output entries in the thesaurus output 180 are generated in a compressed form for file storage. In addition, an index is built on these output files for fast look-up of individual terms.
If a related term (RT) involves an existing knowledge base term, then the knowledge base term is extracted, and the cross-reference relation is added to the knowledge base (blocks 375 , 380 and 385 , FIG. 3 ). Also, the cross-reference relation is added to the thesaurus output 180 (block 390 , FIG. 3 ). The thesaurus compiler generates bi-directional cross-references from the related term (RT) relations (block 395 , FIG. 3 ).
FIG. 4 is a flow diagram illustrating one embodiment for mapping an ISO-2788 entry to a knowledge base. For each preferred term relation, “X PT Y”, an index relation, “X INDEX Y”, is generated (block 400 , FIG. 4 ). For this relation, Y is added to the list of canonical terms (e.g., canonical/alternative form index 140 ). For each synonym relation, “X SYN Y”, an index relation, “X INDEX Z”, is generated, where Z is a canonical term and “Y INDEX Z” exists (block 410 ). For each broader term relation, “X BT Y”, a temporary relation, “X PARENT Y”, is generated (block 420 , FIG. 4 ). Similarly, for each narrower term relation, “X NT Y”, a temporary relation, “Y PARENT X”, is generated (block 430 , FIG. 4 ). In addition, for each Y such that “X PARENT Y”, and there is no “Y PARENT Z”, a top term relation, “Y TT 0”, is generated (block 440 , FIG. 4 ).
FIG. 5 is a flow diagram illustrating one embodiment for building a logical structure for hierarchical relations and cross-references. If an input term, designated term 0 , is a top tree (TT) term and the relation “term x PARENT term 0 ” exists, then the thesaurus compiler 30 generates the hierarchical relation, “term 0NT1 term x ” (blocks 500 and 510 , FIG. 5 ). For purposes of illustrating this embodiment, term x is defined as a term in the input terminological information 110 ( FIG. 1 ). If the relation term x PARENT term x+1 exists, then the thesaurus compiler 130 generates the hierarchical relation, “term x+1 NT (n) term x ” (blocks 520 and 530 , FIG. 5 ). The process of assigning a level in the knowledge base 155 to the mapping occurs for each term in the input terminological information 110 (blocks 540 and 550 , FIG. 5 ).
If term 0 is not a top level term and/or “term x PARENT term 0 ” relation does not exist, then the term 0 is matched to the appropriate level, NT n , in the tree structure (blocks 500 and 565 , FIG. 5 ). Similar to the process described above, the relations “term 0 PARENT term x ,” and “term x PARENT term x+1 ” are mapped to the appropriate level in the knowledge base 155 for each term in the input terminological information 110 (blocks 570 , 575 , 580 , 585 , 590 , and 595 , FIG. 5 ).
For each canonical X with the designation TT or NT n relation, a relation “X concept X” is generated (block 555 , FIG. 5 ). Also, the relation “X RT Y” is translated to the relations “X XREF Y” and “Y XREF X” (block 560 , FIG. 5 ).
The integration of user specified terminological information into a built-in knowledge base has application for use in specific domains. For example, an English language newspaper in India may buy a natural language processing system (e.g., Oracle® ConText®) to provide a search capability for their on-line edition. However, the newspaper agency may find that the built-in knowledge base has little or no knowledge of Indian politics and economics. For this hypothetical, the user desires to extend the built-in knowledge base to include terminological information on Indian politics and economics. The built-in knowledge base (e.g., knowledge base 155 ) has a category for “politics”, but all sub-categories associated with this node apply generally to United States politics. For this hypothetical, the India newspaper may build a hierarchy of terms for “Indian politics” under the existing “politics” category in the knowledge base. Specifically, names of major Indian political parties and politicians are organized and represented in the ISO-2788 thesaurus format. Table 3 shows an example input terminological information formatted in the ISO-2788 thesaurus format.
TABLE 3
Congress Party of India
BT politics
BJP
SYN Bharatiya Janata Party
Bharatiya Janata Party
BT politics
RT Hinduism
FIG. 6 a illustrates a logical structure for the terminological information of Table 3 configured in accordance with one embodiment. Specifically, for this example, the categories “Congress Party of India” and “Bharatiya Janata Party” and “BJP” are children nodes under the existing “politics” category of the knowledge base. FIG. 6 a also shows the related term (RT) relation between “BJP” and “Hinduism” through generation of a two-way cross-reference between the categories.
The terminological system also has application for use to generate logical structures detached from any ontology in the built-in knowledge base. For example, a customer may desire to add some foreign language (e.g., Hindi) terms that are commonly used in “Indian English.” The customer of the natural language processing system may decide that it is useful to keep the foreign language terms separate from the rest of the terminology used in the natural language processing system (i.e., perhaps because the new ontology will be treated differently in the NLP application). For this example, a customer may build a thesaurus of terms that do not have any hierarchical (BT/NT) or related terms that link the input terminological information to existing terms in the knowledge base. For this example, the thesaurus compiler creates a new tree of terms and augments the built-in knowledge base to include an additional independent ontology. Table 4 shows an example independent ontology for terms under the top level (TT) “Indian politics”, formatted in the ISO-2788 standard.
TABLE 4 CPI SYN Congress Party of India BT Indian politics Mrs. Gandhi BT CPI FIG. 6 b illustrates a hierarchical structure for the example input terminological information of Table 4.
The terminological system 100 also “splices” two branches from different trees to integrate input terminological information to a built-in knowledge base. For example, the term “CPI” is a synonym for “Consumer Price Index” in the built-in knowledge base. However, in an Indian context, the term means “Congress Party of India.” Table 4 shows example input terminological information formatted in the ISO-2788 standard. This example includes the term “CPI” in the Indian context. FIG. 6 c illustrates an example portion of an ontology for the parent category “macro economic measures” for the built-in knowledge base example. As shown in FIG. 6 c , the term “CPI” already exists in the “macro measures” branch. For this example, the user desires to associate the term “CPI” under the category “politics”, but does not want to delete the term “Consumer Price Index.” In addition, the user may not even know that “CPI” is mapped to the concept of “Consumer Price Index” in the built-in knowledge base. For this example, the terminological system 100 splices the “CPI” term from the economics branch, attaches it to the “politics branch” at the appropriate location, and sews the economics branch back together.
FIG. 6 d illustrates one example of modifying the built-in knowledge base of FIG. 6 c to avoid conflict with the input terminological information of Table 4 and FIG. 6 b . Specifically, the built-in knowledge base was modified such that the category “inflation” now points to “Consumer Price Index”, instead of “CPI.” This operation occurs without the user having to recognize and resolve such conflicts or having to translate input terminological information to the internal representation formats used by the natural language processing system.
FIG. 7 is a flow diagram illustrating one embodiment for resolving conflicts among one or more terms of the input terminological information with terms of the built-in knowledge base. If an input term exists as a node in the built-in knowledge base, and the input term and term of the knowledge base have the same connotation, then that existing node is deleted from the built-in knowledge base (blocks 700 , 710 and 720 , FIG. 7 ). If one or more child nodes exist and a parent node exists for that term, then the parent category of the relation parent-node is logically coupled to the child of the relation node-child (blocks 730 , 740 and 760 , FIG. 7 ). However, if a child node exists but a parent node does not exist, then hierarchy levels are upgraded from NT 1 to TT and from NT n to NT n−1 (blocks 730 , 740 and 750 , FIG. 7 ). Also, if any concepts to the deleted node exist, then those concepts are mapped to the parent/child node (block 780 , FIG. 7 ).
In one embodiment, the input terminological information 110 ( FIG. 1 ) consists of up to sixteen thesauri. In one embodiment, the maximum length of a term is 80 characters. The following rules are implemented in a system in accordance with one embodiment. The broader term generic (BTG) and broader term partitive (BTP) are treated the same as the broader term (BT) relation. Similarly, narrower term generic (NTG) and narrower term partitive (NTP) are the same as narrower term since the knowledge base 155 embodiment does not distinguish between partitive and generic hierarchical relations. Only preferred terms have narrower term or related term relations. Other terms may or may not have a preferred term. If they do, they cannot have an NT or RT relation. If a term has no synonym (SYN) or preferred term (PT) it will be treated as its own preferred term. This in addition to the rule below guarantees that every term has exactly one canonical form. If a set of terms is related by SYN relations, only one of the terms is a preferred term. If a term that is not a preferred term has a broader term, it must be to the same term as the broader term of its preferred term. This guarantees that a term has only one parent in the knowledge base hierarchy. A top term may not have a broader term. Only preferred terms may be TTs. An existing term in the built-in knowledge base cannot be a TT. A preferred term that does not have a BT relation must be a TT (i.e., the root of every tree must be declared a top term). A BT or NT relation cannot be between two terms from the built-in knowledge base. There may be no cycles in BT and NT relations. A term can have at most one PT and at most one BT. A term may have any number of NTs. An RT of a term cannot be an ancestor or descendant of that term. A preferred term may have any number of RTs. The maximum height of a tree is sixteen, including the TT level. Although the above-identified rules facilitate integration of input terminological information for one embodiment of a built-in knowledge base (i.e., knowledge base 155 ), implementation of these rules are not required to integrate input terminological information into a built-in knowledge base.
Natural Language Processing System:
FIG. 8 is a block diagram illustrating one embodiment for a natural language processing system incorporating the integrated knowledge base of the present invention. A natural language processing system 800 includes a content processing system 810 and a search and retrieval system 820 . For this embodiment, the content processing system 810 receives discourse, denoted as documents 840 , analyzes the documents, and generates classification as well as other information regarding the documents. One embodiment for a content processing system is described in U.S. Pat. No. 5,694,523. The content processing system integrates use of both the built-in knowledge base and the thesaurus output to analyze, classify and process the documents 840 .
The search and retrieval system 820 receives an input search query 850 , and generates output results 890 , that include one or more relevant documents from a repository of documents 830 . The search and retrieval system 820 utilizes an integrated built-in knowledge base and thesaurus output 870 to process the input search query 850 to generate the output results 890 .
Computer System:
FIG. 9 illustrates a high level block diagram of a general purpose computer system in which the natural language system and thesaurus compiler of the present invention may be implemented. A computer system 1000 contains a processor unit 1005 , main memory 1010 , and an interconnect bus 1025 . The processor unit 1005 may contain a single microprocessor, or may contain a plurality of microprocessors for configuring the computer system 1000 as a multi-processor system. The main memory 1010 stores, in part, instructions and data for execution by the processor unit 1005 . If the natural language system and thesaurus compiler of the present invention is wholly or partially implemented in software, the main memory 1010 stores the executable code when in operation. The main memory 1010 may include banks of dynamic random access memory (DRAM) as well as high speed cache memory.
The computer system 1000 further includes a mass storage device 1020 , peripheral device(s) 1030 , portable storage medium drive(s) 1040 , input control device(s) 1070 , a graphics subsystem 1050 , and an output display 1060 . For purposes of simplicity, all components in the computer system 1000 are shown in FIG. 9 as being connected via the bus 1025 . However, the computer system 1000 may be connected through one or more data transport means. For example, the processor unit 1005 and the main memory 1010 may be connected via a local microprocessor bus, and the mass storage device 1020 , peripheral device(s) 1030 , portable storage medium drive(s) 1040 , graphics subsystem 1050 may be connected via one or more input/output (I/O) busses. The mass storage device 1020 , which may be implemented with a magnetic disk drive or an optical disk drive (e.g., compact disc (CD)), is a non-volatile storage device for storing data and instructions for use by the processor unit 1005 . In the software embodiment, the mass storage device 1020 stores the natural language system and thesaurus compiler software for loading to the main memory 1010 .
The portable storage medium drive 1040 operates in conjunction with a portable non-volatile storage medium, such as a floppy disk or a compact disc read only memory (CD-ROM), to input and output data and code to and from the computer system 1000 . In one embodiment, the natural language system and thesaurus compiler software is stored on such a portable medium, and is input to the computer system 1000 via the portable storage medium drive 1040 . The peripheral device(s) 1030 may include any type of computer support device, such as an input/output (I/O) interface, to add additional functionality to the computer system 1000 . For example, the peripheral device(s) 1030 may include a network interface card for interfacing the computer system 1000 to a network. For the software implementation, input terminological information may be input to the computer system 1000 via a portable storage medium or a network for processing by the thesaurus compiler.
The input control device(s) 1070 provide a portion of the user interface for a user of the computer system 1000 . The input control device(s) 1070 may include an alphanumeric keypad for inputting alphanumeric and other key information, a cursor control device, such as a mouse, a trackball, stylus, or cursor direction keys. In order to display textual and graphical information, the computer system 1000 contains the graphics subsystem 1050 and the output display 1060 . The output display 1060 may include a cathode ray tube (CRT) display or liquid crystal display (LCD). The graphics subsystem 1050 receives textual and graphical information, and processes the information for output to the output display 1060 . The components contained in the computer system 1000 are those typically found in general purpose computer systems, and in fact, these components are intended to represent a broad category of such computer components that are well known in the art.
The thesaurus compiler techniques may be implemented in either hardware or software. For the software implementation, the thesaurus compiler is software that includes a plurality of computer executable instructions for implementation on a general purpose computer system. Prior to loading into a general purpose computer system, the natural language system and thesaurus compiler software may reside as encoded information on a computer readable medium, such as a magnetic floppy disk, magnetic tape, and compact disc read only memory (CD-ROM). In one hardware implementation, the natural language system and thesaurus compiler may comprise a dedicated processor including processor instructions for performing the functions described herein. Circuits may also be developed to perform the functions described herein.
Although the present invention has been described in terms of specific exemplary embodiments, it will be appreciated that various modifications and alterations might be made by those skilled in the art without departing from the spirit and scope of the invention.
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A terminological system automates the integration of terminological information into a built-in knowledge base. Input terminology information, which includes input terms and information that specifies relationships among at least two of the input terms, is input to the terminological system. The terminological system parses the input terminology information to generate a logical structure that depicts relationships among the input terms in a format compatible with the built-in knowledge base. Either an independent ontology, comprising the logical structure, is generated, or the knowledge base is extended by logically coupling the logical structure to a node that matches the input term. The terminological system also resolves conflicts if an input term that matches a terminological node in the knowledge base connotes a different meaning than the terminological node. A system that converts broader term and narrower term relationships, synonym relationships, related term (RT) relationships, and preferred term (PT) relationships in accordance with the ISO 2788 standard is disclosed.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation-In-Part of U.S. patent application Ser. No. 10/800,788 filed Mar. 16, 2004, currently still pending, which was itself a Continuation-In-Part of U.S. patent application Ser. No. 10/752,430 filed on Jan. 6, 2004, now U.S. Pat. No. 7,005,549, and claims the benefit of U.S. Provisional Application No. 60/438,114 filed Jan. 6, 2003 the entire contents of which are herein incorporated by reference.
TECHNICAL FIELD
[0002] This invention relates generally to processes for producing organic peroxy acids and more particularly to the use of chemical precursors from which peroxygen acids (peroxy acetic, peroxy propionic, etc.) may be advantageously prepared upon mixing the precursors with hydrogen peroxide or a source of peroxide, such as percarbonate or perborate anions.
BACKGROUND
[0003] Peroxy acids, and peroxyacetic acid in particular, have been used for cleaning and disinfecting various surfaces and implements, including medical devices such as endoscopes, and environmental surfaces, including countertops, ductwork, etc. However, one drawback associated with the use of solutions of peroxyacetic acid and other peroxy acids in general is that the shelf life of such solutions is limited to a few months, due to the inherent instability of the materials. Even very low concentrations of the peroxyacetic species, such as those used to disinfect surfaces (i.e., 0.05% to about 5%) are too unstable for a useful commercial shelf life.
[0004] One way to overcome shelf life issues may be to employ a solid formulation which is mixed with water shortly before needed. Active precursor components, including a solid form of hydrogen peroxide such as an alkali metal or alkaline earth metal percarbonate or perborate salt can be combined with an acyl donor, such as either tetraacetylethylenediamine (“TAED”) or acetylsalicylic acid (“ASA”) to yield a peroxy acid according to the scheme conducted in aqueous media:
the peroxide being present from reaction of the perborate or percarbonate with water, which is subsequently available to react with the acyl compound. In the foregoing reaction, the radical X represents the remaining residue of the TAED or ASA molecule, such as in the case of ASA wherein it represents the ASA molecule minus the acetyl group. However, we do not consider TAED and ASA to be efficient acylating agents, in that a relatively large mass of useless carbon-containing byproducts are generated when these reactants are employed. In addition, the kinetics of the reaction are not as favorable as would be desired, because quick generation of appreciable quantities of peroxyacetic acid from ASA according to the above scheme requires a reaction temperature above room temperature.
[0005] While peroxyacetic acid has been used to disinfect medical equipment such as endoscopes and related items, peroxypropionic acid (“PPA”) has not been developed for such purposes. Precursors according to one embodiment of the present invention have the distinct advantage that they can be used to easily produce novel antimicrobial formulations which contain PPA, as well as a whole host of other peroxy acids which consume less weight of hydrogen peroxide during their production per mole of peroxy acid produced, than commercial precursors acetyl salicylic acid (ASA) and tetraacetylethylenediamine (TAED). Additionally, precursors according to an embodiment of the present invention allow for the formulation of antimicrobial compositions that have room temperature stability in their concentrated forms, and which can alternatively be packaged in dry powder form for reconstitution by combination with hydrogen peroxide, or a hydrogen peroxide precursor/water mixture at the site of their end use. The resulting peroxide-containing liquids can be readily delivered in liquid or gaseous form at the site of use. The dry powder form of a compound according to one embodiment, or its concentrate may also be applied to the site of use and activated with hydrogen peroxide or water in combination with a hydrogen peroxide precursor.
[0006] Thus, in summary, provided are novel water-soluble precursors useful for efficiently generating peroxy acids. When using a precursor according to an embodiment of the present invention, there are less by-products generated for every mole of peroxy acid generated. Further, a smaller weight of the precursor provided by the present invention is required to generate a mole of peroxy acid than when using a prior art material and/or method. The acyl precursors provided by an embodiment of the present invention are generally more water-soluble than ASA, relatively inexpensive to manufacture, and consume less weight of acyl precursor per mole of peroxy acid generated than the corresponding ASA.
[0007] Uses for the solutions provided by the embodiments of the invention include, without limitation: emergency disinfection of wounds by mixing dry powder with water; disinfection of surgical facilities and medical treatment rooms; chemical sterilization of surgical equipment and instruments, particularly endoscopes; disinfection of medical devices; disinfection of animal enclosure areas such as used by horses, cattle, dogs, cats, etc.; remediation of mold in buildings, the contents of buildings; disinfecting plants and foodstuffs, including meats, vegetables, and fruits; disinfection of surfaces from vegetative bacteria, molds, fungi and their spores, especially for remediation in non-line-of-slight applications; and liquid disinfectants of equipment such as tanks, passenger cars, all military vehicles, aircraft, and related equipment.
SUMMARY OF THE INVENTION
[0008] Provided are compositions useful for forming peroxygen acids, which compositions comprise a nitrogenous compound having the structure:
in which L is a divalent radical that is independently selected from the group consisting of:
and wherein R 1 , R 2 R 3 , and R 4 are each independently selected from the group consisting of: hydrogen, any C 1 to C 20 hydrocarbyl group, and the group:
subject to the proviso that: at least one of R 1 , R 2 , R 3 , and R 4 are the group:
in which R 5 is in each occurrence independently hydrogen or any C 1 to C 20 hydrocarbyl group.
[0009] According to an alternate embodiment, one and only one of R 1 , R 2 , R 3 , and R 4 is the group:
in which R 5 is independently hydrogen or any C 1 to C 20 hydrocarbyl group. A variant of such alternate embodiment is where at least one of the groups of R 1 , R 2 , R 3 , and R 4 which are not the group:
is hydrogen. Another variant is where at least one of the groups of R 1 , R 2 , R 3 , and R 4 which are not the group:
is independently in each occurrence any C 1 to C 20 hydrocarbyl group.
[0010] According to another alternate embodiment, any two of R 1 , R 2 , R 3 , and R 4 are the group:
in which R 5 is independently in each occurrence hydrogen or any C 1 to C 20 hydrocarbyl group. One variant of this alternate embodiment is where at least one of the groups of R 1 , R 2 , R 3 , and R 4 which are not a group:
is hydrogen. Another variant of this alternate embodiment is where at least one of the groups of R 1 , R 2 , R 3 , and R 4 which are not a group:
is independently in each occurrence any C 1 to C 20 hydrocarbyl group.
[0011] According to another alternate embodiment, any three of R 1 , R 2 , R 3 , and R 4 are the group:
in which R 5 is independently in each occurrence hydrogen or any C 1 to C 20 hydrocarbyl group, and the group of R 1 , R 2 , R 3 , and R 4 which is not a group:
is hydrogen. One variant of this alternate embodiment is where the group of R 1 , R 2 , R 3 , and R 4 which is not a group:
is any C 1 to C 20 hydrocarbyl group. Another variant of this alternate embodiment is where all of R 1 , R 2 , R 3 , and R 4 are the group:
in which R 5 is independently in each occurrence hydrogen or any C 1 to C 20 hydrocarbyl group.
[0012] A fourth alternate embodiment is where R 1 and R 4 are represented by the group:
in which R 5 is independently in each occurrence hydrogen or any C 1 to C 20 hydrocarbyl group, and wherein R 2 and R 3 are each independently selected from the group consisting of: hydrogen, and any C 1 to C 20 hydrocarbyl group. A variant of this fourth general embodiment is where R 5 in each occurrence is selected from the group consisting of: methyl, ethyl, 1-propyl, and 2-propyl.
[0013] The aforesaid nitrogenous compounds are generally solids at room temperature, and it is a routine matter to dry them to powder form. Thus, is a simple matter to mix a nitrogenous compound of the invention with any number of other solid compounds which upon being contacted with water yield a peroxide, such as hydrogen peroxide and peroxide ions. Examples of such materials include alkali metal and alkaline earth metal salts of percarbonates and perborates. According to one embodiment, a composition is provided which comprises a dry powder that includes a nitrogenous compound according to one embodiment of the invention and a source of peroxide, and it is preferred that the nitrogenous compound is present between about 0.1% and about 5% by weight based on the total weight of said composition.
[0014] Also provided is a process for providing an aqueous peroxy acid comprising contacting a composition containing a nitrogenous compound according to an embodiment of the invention with an aqueous peroxide, such as hydrogen peroxide or any other source of peroxide ions. An aqueous solution provided according to one embodiment of the invention may contain water present in any amount between about 80% and about 99.95% by weight based on the total weight of the aqueous solution, and the nitrogenous compound(s) may be present in any amount between about 0.1% and about 10% by weight based upon the total weight of such aqueous solution, including any and all ranges therebetween. Various additives may be optionally included in such aqueous solutions, including buffers, surfactants, sequesterants, as such are known to those skilled in the art.
[0015] The invention also provides compositions which comprise an aqueous solution of a nitrogenous compound as set forth herein which further comprise at least one solid peroxide-generating compound which upon being contacted with water yields a peroxide, such as hydrogen peroxide or peroxide ions. Typical examples of suitable solid compounds include alkali metal and alkaline earth metal salts of percarbonates and perborates. One embodiment provides for the peroxide-generating compound to be present in any amount between about 0.01% and about 5% by weight based upon the total weight of the aqueous solution.
[0016] Also provided are methods for disinfecting surfaces by contacting any surface with a mixture comprising: water, any of the various nitrogenous compound provided herein, and any source of peroxide, such as hydrogen peroxide or peroxide ions.
[0017] Also provided are methods for volatilizing a peroxy acid by mixing water, a nitrogenous compound described herein, and a source of peroxide, such as hydrogen peroxide or peroxide ions, under conditions sufficient to enable evolution of a peroxy acid vapor from aqueous solution, or liberation of a peroxy acid vapor from an aqueous solution. Many peroxy acids are sufficiently volatile so as to auto-vaporize at room temperature and pressure. However, one alternate form of the invention employs conventional vaporization equipment and methods such as sonication, heating, and venturi effect to provide vapors of peroxy acids. Such known equipment and methods can be used with peroxy acids that are readily volatilized, and for providing vapors of peroxy acids that don't readily volatilize on their own.
DETAILED DESCRIPTION
[0018] One embodiment of the present invention provides chemical precursors from which organic peroxy acids may be prepared upon their being mixed with hydrogen peroxide or other peroxide precursors, such as percarbonates or perborates anions or species, in aqueous media. The nitrogenous compounds useful in accordance with the invention include those described by the chemical formula:
in which L is a divalent radical that is independently selected from the group consisting of:
and wherein R 1 is independently any C 1 to C 20 hydrocarbyl group; R 2 is independently selected from the group consisting of: hydrogen, any C 1 to C 20 hydrocarbyl group, and the group:
in which R 5 is independently hydrogen or any C 1 to C 20 hydrocarbyl group; R 3 is independently selected from the group consisting of: hydrogen and any C 1 to C 20 hydrocarbyl group; and R 4 is independently selected from the group consisting of: hydrogen, and the group
in which R 5 is independently hydrogen or any C 1 to C 20 hydrocarbyl group.
[0019] The nitrogenous compounds of this embodiment can be conveniently prepared by reacting an acid halide of a carboxylic acid with various substituted or unsubstituted sulfamides and sulfoxamides in an appropriate solvent, as known to those skilled in the art. An acid halide of a carboxylic acid is often referred to by those skilled in the art as simply an “acid halide”. Acid halides of carboxylic acids, (including without limitation alkyl carboxylic acids, aryl carboxylic acids and alkylaryl carboxylic acids), are well known in the art, and are believed to be described in all reputable college-level organic chemistry textbooks, one example being “Introduction to Organic Chemistry”, by Streitweiser and Heathcock, 2 nd ed. MacMillan Publishing Company, New York (1981), the entire contents of which are herein incorporated by reference, especially pages 517, et seq. The acid halides of carboxylic acids may be formed as the reaction product between a carboxylic acid and a suitable halogenating agent such as the trichloride and pentabromide of phosphorous, or the thionyl halides such as thionyl chloride and thionyl bromide, under conditions well known to the organic chemist. In the formation of acid halides by this route, the hydroxy group of the carboxylic acid function is replaced by a halogen atom, usually chlorine or bromine. Thus, in general, an acid halide useful for forming a nitrogenous compound in accordance with the present invention has the chemical structure:
in which R is any C 1 to about C 20 hydrocarbyl group, and in which X is any halogen atom. This definition includes the acid halides of alkyl carboxylic acids, as well as the acid halides of aryl carboxylic acids and alkylaryl carboxylic acids. According to one preferred form of the invention, the halogen atom X comprises bromine or chlorine.
[0020] The term “hydrocarbyl”, when referring to a substituent or group in the present specification and the claims appended hereto is used in its ordinary sense, which is well-known to those skilled in the art. Specifically, it means a group having a carbon atom directly attached to the remainder of the molecule and having predominantly hydrocarbon character. Examples of hydrocarbyl substituents or groups include: (1) hydrocarbon substituents, that is, aliphatic (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, and aromatic-, aliphatic-, and alicyclic-substituted aromatic substituents, as well as cyclic substituents wherein the ring is completed through another portion of the molecule (e.g., two substituents together form an alicyclic radical); (2) substituted hydrocarbon substituents, that is, substituents containing non-hydrocarbon groups which, in the context of this invention, do not alter the predominantly hydrocarbon substituent (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, and sulfoxy); (3) hetero substituents, that is, substituents which, while having a predominantly hydrocarbon character, in the context of this invention, contain other than carbon in a ring or chain otherwise composed of carbon atoms. Heteroatoms include sulfur, oxygen, nitrogen, and encompass substituents as pyridyl, furyl, thienyl and imidazolyl. In general, no more than two, preferably no more than one, non-hydrocarbon substituent will be present for every ten carbon atoms in the hydrocarbyl group; typically, there will be no non-hydrocarbon substituents in the hydrocarbyl group. All hydrocarbyl groups are useful within the meaning of R in the above formula for the acid halide, subject to the proviso that no portion of the hydrocarbyl radical R present is detrimentally reactive with the labile carbonyl-halogen bond also present within the time frame of the use of such acid halide in preparation of the targeted precursor.
[0021] Thus, typical acid halides suitable for use in preparing a precursor according to the present invention include, without limitation: acetyl chloride, adipoyl chloride, anisoyl chloride, acryloyl chloride, butyryl chloride, camphoroyl chloride, caproyl chloride, cinnamoyl chloride, cyanoacetyl chloride, formyl chloride, proprionyl chloride, fumaroyl chloride, glutaryl chloride, isophthaloyl chloride, levulinoyl chloride, lauroyl chloride, malonyl chloride, oleoyl chloride, oxalyl chloride, pyruvoyl chloride, salicyloyl chloride, stearoyl chloride, suberoyl chloride, terephthaloyl chloride, thioacetyl chloride, phthaloyl chloride, succinyl chloride, benzoyl chloride, maleyl chloride and toluoyl chloride. In fact, all known acid halides can be useful as acid halides from which a precursor according to the invention may be provided, owing to the presence of an active hydrogen atom in the molecular structure of the co-reactant with which the acid halide is reacted to form the inventive precursors.
[0022] The co-reactant used as a precursor with which an acid halide is reacted in order to form a nitrogenous compound provided by or useful in accordance with the invention is selected from the group consisting of substituted or unsubstituted sulfamides and sulfoxamides. Sulfamide is a compound well-known to have the structure:
and sulfoxamide is a compound well known in the art to have the structure:
Each of these compounds comprise two nitrogen atoms, each of which have at least one active hydrogen atom attached thereto. For purposes of this invention and the appended claims, a hydrogen atom attached to a nitrogen atom of a substituted or unsubstituted sulfamide or sulfoxamide is considered to be an active hydrogen atom if it is capable of participating in the Zerevitinov reaction (Th. Zerevitinov, Ber. 40, 2023 (1907)) to liberate methane from methylmagnesium iodide. Further, each of these compounds sulfamide and sulfoxamide continue to contain an active hydrogen atom when one or more of their nitrogen atoms are mono-substituted with a hydrocarbyl group, thus rendering them reactive with an acid halide and suitable for use in providing a nitrogenous compound according to the invention. For convenience, the substituted and unsubstituted sulfamides and sulfoxamides that may be used as an initial raw material in providing a composition or compound that is useful according to embodiments the invention may be collectively denoted as:
in which L is a divalent radical that is selected from the group consisting of:
and wherein R 2 and R 3 are each independently selected from the group consisting of: hydrogen and any C 1 to C 20 hydrocarbyl group.
[0023] Thus, the preparation of a precursor according to one preferred embodiment of the invention may be accomplished by conducting the reaction:
with the L and R groups being as herein defined. In such reaction, one mole of acid halide is shown to be reacted with each mole of substituted or unsubstituted sulfamide (or sulfoxamide when selected) reactant, and although not specifically written, in the process a mole of hydrogen halide HX is liberated. However, those of ordinary skill in the art readily appreciate that more than one mole of acid halide may be employed per mole of sulfamide (or sulfoxamide when selected). Particularly, when R 2 and R 3 are both hydrogen, it is possible to append up to four groups having structure:
in which R 5 is independently hydrogen or any C 1 to C 20 hydrocarbyl group, to the starting material:
[0024] Thus, one embodiment of the invention provides a precursor which may be formed according to the reaction:
in which 2 moles of the same acid halide are reacted with each mole of sulfamide (or sulfoxamide, when selected), and in such a reaction two moles of hydrogen halide HX are liberated. In the above two reactions, the identities of the various substituents are as previously described, namely L is a divalent radical that may be either of
and R 1 may be any C 1 to C 20 hydrocarbyl group; and R 2 and R 3 are each independently selected from the group consisting of: hydrogen and any C 1 to C 20 hydrocarbyl group.
[0025] These reactions fall under the general reaction:
in which L is a divalent radical that may be either of
n preferably has the value of either one or two; R 1 may independently be any C 1 to C 20 hydrocarbyl group; R 2 , and R 3 in the reactant may independently be hydrogen, or any C 1 to C 20 hydrocarbyl group, and R 2 and R 3 in the product are each independently hydrogen, any C 1 to C 20 hydrocarbyl group, or the group:
in which R 5 is independently hydrogen or any C 1 to C 20 hydrocarbyl group, and R 4 is hydrogen or the group:
in which R 5 is independently hydrogen or any C 1 to C 20 hydrocarbyl group. Alternate preferred embodiments include the cases where n is selected to be 3 when at least one of R 2 and R 3 in the reactant are hydrogen, and where n is selected to be 4 when both of R 2 and R 3 in the reactant are hydrogen. The liberated HX is not specified in the general reaction but is recognized as being liberated by those skilled in the art, in a quantity that depends upon the total amount of acid halide and active hydrogen atoms present in the reactant sulfamide or sulfoxamide.
[0026] Thus, using a process as described above in combination with the specified starting materials, the invention provides compositions of matter useful for forming peroxygen acids, which comprise a nitrogenous compound having the structure:
in which L is a divalent radical that is independently selected from the group consisting of:
and wherein R 1 , R 2 , R 3 , and R 4 are each independently selected from the group consisting of: hydrogen, any C 1 to C 20 hydrocarbyl group, and the group:
in which R 5 is in each occurrence independently hydrogen or any C 1 to C 20 hydrocarbyl group. In a preferred embodiment, at least one of R 1 , R 2 R 3 , and R 4 are the group:
in which R 5 is in each occurrence independently hydrogen or any C 1 to C 20 hydrocarbyl group. In another preferred embodiment, at least one of R 1 and R 2 are the group:
in which R 5 is in each occurrence independently hydrogen or any C 1 to C 20 hydrocarbyl group and at least one of R 3 and R 4 are the group:
in which R 5 is in each occurrence independently hydrogen or any C 1 to C 20 hydrocarbyl group.
[0027] The processes in all of the these reactions set forth above are considered to be acylation reactions, and their reaction products are useful in preparing solutions containing peroxygen acids upon their being mixed with an aqueous peroxide such as hydrogen peroxide or a peroxide precursor, such as percarbonate or perborate anions, in aqueous media. The acylation reactions described above for preparing the precursors are preferably carried out in a solvent, which solvent is preferably an organic solvent in which the acid halide and sulfamide (or sulfoxamide, when employed) are mutually soluble. In addition, it is preferable to add a small amount of tertiary amine, such as a tri-alkyl amine such as triethylamine, trimethylamine, pyridine, etc. to the solution to facilitate the reaction between the acid halide and sulfamide (or sulfoxamide), as the use of tertiary amines for this purpose is known in the art.
[0028] It will be immediately recognized by those skilled in the art upon reading this specification that the identity of the hydrocarbyl groups R 1 and R 5 will often be the same, as in those cases when two moles of acid halide are combined with one mole of the sulfamide (or sulfoxamide when selected). However, it is possible for the identities of the hydrocarbyl groups R 1 and R 5 to be different from one another in a precursor product according to the invention, and such result is readily accomplished by first reacting a selected sulfamide (or sulfoxamide) having two active hydrogen atoms, either on the same nitrogen atom or on different nitrogen atoms, with a first acid halide, and then subsequently reacting the acylated product with a second acid halide having an R group that differs from that of the first acid halide. During the course of such reactions, owing to thermodynamic and kinetic equilibria, it is statistically probable that a portion of the reaction product will be one in which R 2 may comprise the group:
in which R 5 may comprise the same group as R 1 , for the case when two moles of acid halide are reacted in a single reaction step with each sulfamide (or sulfoxamide) present, when the sulfamide (or sulfoxamide) initially comprises two active hydrogen atoms attached to the same nitrogen in the reactant (with R 3 and R 4 being as specified above) By the same token, in an alternate form of the invention R 5 in a radical:
in the position of R 2 may comprise a different group than R 1 , for the case when two moles of acid halide are reacted in two separate reaction steps with each sulfamide (or sulfoxamide) present, when the sulfamide (or sulfoxamide) initially comprises two active hydrogen atoms attached to the same nitrogen in the reactant. Thus, although the most kinetically favored reaction product is represented by:
there will nevertheless also be present certain quantities of material represented by the structure:
the relative amount of which depends on the nature of the R 1 group, as is readily appreciated by those skilled in the art, when the R 2 group in the reactant which results from the monoacylation of the sulfamide (or sulfoxamide) raw material:
comprises hydrogen. Thus, the present invention also includes compositions having the general structure:
in which R 2 comprises the radical:
in which R 5 is independently hydrogen or any C 1 to C 20 hydrocarbyl group. However, the preferred inventive compounds are those described by the formula:
in which L is a divalent radical that is independently selected from the group consisting of:
and wherein R 1 is independently any C 1 to C 20 hydrocarbyl group; R 2 and R 3 are each independently selected from the group consisting of: hydrogen and any C 1 to C 20 hydrocarbyl group; and R 4 is independently selected from the group consisting of: hydrogen, and the group
in which R 5 is independently hydrogen or any C 1 to C 20 hydrocarbyl group are water soluble at room temperature, are more efficient in generating peracids than currently-available commercial precursors, and these materials can be advantageously used as solid precursors to peroxy acids when mixed with hydrogen peroxide or a hydrogen peroxide precursor such as percarbonate or perborate.
[0029] The following preparatory methods are intended to be exemplary of the present invention and shall not be construed to be delimitive thereof in any respect.
EXAMPLE 1
[0030] Synthesis of diproprionyl sulfamide—To 100 ml of toluene in a flask equipped with a reflux condenser and a mechanical stirrer under moderate agitation are added 9.6 grams of sulfamide and 10.1 grams of triethylamine, and stirring is continued until complete dissolution occurs. Next, 9.25 grams of proprionyl chloride is added dropwise with stirring over the course of about 15 minutes, while the temperature of the flask is maintained below 60° C. After the addition of the proprionyl chloride is complete, the mixture is allowed to cool to room temperature, after which time it is filtered to remove the triethylamine hydrochloride by-product, which is discarded. The toluene is removed using a rotary evaporator until crystals just begin to form, at which time the flask contents are cooled to between about 2-8° C. overnight to complete crystallization process. The product is filtered, dried under vacuum, and stored in a dessicator. The overall reaction is:
EXAMPLE 2
[0031] The procedure according to Example 1 is followed, except 13.0 grams of propionic anhydride is utilized in place of the proprionyl chloride.
EXAMPLE 3
[0032] Synthesis of dipropionyl sulfoxamide—To 100 ml of toluene in a round bottom flask equipped with a reflux condenser and a mechanical stirrer under moderate agitation are added 8.0 grams of sulfoxamide and 10.1 grams of triethylamine until dissolution is complete. Subsequently, 9.25 grams of proprionyl chloride is added dropwise with stirring by means of an addition funnel while taking care to maintain the mixture below 60° C. Following the addition the mixture is allowed to cool to room temperature, and is filtered to remove triethylamine hydrochloride by-product, which is discarded. The toluene is evaporated using a rotary evaporator until crystals just begin to form, after which time the contents of the flask are cooled to between 2-8° C. and allowed to stand overnight to complete crystallization process. The product is filtered, dried under a vacuum, and stored in a dessicator the overall reaction is:
EXAMPLE 4
[0033] The procedure according to Example 3 is followed, except that 13.0 grams of propionic anhydride is utilized in place of the proprionyl chloride.
Practical Use Example
[0034] An equimolar amount of sodium perborate and diproprionyl sulfamide are mixed with water sufficient to generate ˜0.4% perpropionic acid. To make one liter of product mix 4.8 grams of diproprionyl sulfamide with 4.65 grams of sodium perborate and add one liter of water. The reaction mixture will be initially basic, then as the reaction proceeds the pH will drop. Sufficient buffer such as sodium dihydrogen phosphate should be added such that the final pH is between ˜6.5 and ˜7.0. To enhance microbial activity, ionic or nonionic surfactants such as dodecylbenzenesulfonic acid or Pluronic™ surfactants (BASF) may be added. Sequestering agents such as ethylenediaminetetraacetic (EDTA) acid may also be added.
[0035] For the sake of stability of an aqueous solution containing a nitrogenous compound according to embodiments of the invention, it is preferred that the aqueous solution contain a pH buffer. The buffer chosen is not critical as long as the pH is maintained preferably in the range of between about 5.0 to 7.0. A vast number of buffers are known to those skilled in the art, and any buffer known to those skilled in the art as being useful for maintaining an aqueous solution that contains a nitrogenous compound according to the invention in the range specified above may be used for this purpose, with the main proviso for suitability being that the components of such buffer are preferably stable with respect to the other chemical species in the aqueous solution and do not react therewith. Suitable buffer systems thus include without limitation: phosphate buffers; sulfate buffers; acetic/acetate buffers; propionic/proprionate buffers; C 1 -C 10 mono- and polycarboxylic acid buffers; substituted carboxylic acids such as lactic, ascorbic, and tartaric acid buffers; and carboxylic acids that have unsaturation such as maleic and furmaric buffers. Buffer systems are known to contain salt pairs. Currently, the most preferred buffer is the dihydrogen phosphate buffer, adjusted to a pH of about 6.5.
[0036] Sequesterants may be used to advantage as a component of an aqueous solution that contains a nitrogenous compound according to the invention, for tying up or otherwise rendering chemically unavailable various species which may otherwise tend to interfere with the performance of the compounds and/or solutions of the invention. Suitable sequesterants include those commonly employed in the surfactant and other industries, including without limitation EDTA and its analogs, or analogous phosphonic acid salts, tartarates, citrates, and other species recognized by those skilled in the art as capable of functioning as a sequesterant.
[0037] Other soluble conventional materials may be present to advantage as a component of an aqueous solution that contains a nitrogenous compound according to embodiments of the invention, including corrosion inhibitors, dyes, perfumes, germicides, preservatives, e.g., QUATERNTUM™ 15 (Dow Chemical), anti-tarnishing agents, surfactants (for example anionic, cationic, nonionic, amphoteric or mixtures thereof), thickeners, chelating agents, antioxidants, and the like. Such other conventional materials may be used in the amounts they are normally used generally up to about 5% by weight, more preferably up to about 3% by weight.
[0038] Also provided by embodiments of the invention are processes for disinfecting a surface (including surfaces of implements such as surgical implements and other medical equipment or wares) which comprises the step of contacting a surface with an aqueous composition that is formed from mixing water, a source of peroxide, and a nitrogenous compound as described herein. Such a mixture contains a peroxy acid, whose identity is readily controllable by selecting the various molecular appendages, and such solutions have powerful disinfectant properties. Any source of peroxide, including those herein described are suitable, including hydrogen peroxide. In some embodiments, the source of peroxide is a solid compound, which upon being contacted with water yields a peroxide, including alkali metal salts and alkaline earth metal salts of percarbonates and perborates. Persulfates of these cations are suitable as are alkali metal and alkaline earth metal peroxides. In some embodiments, the aqueous composition which contains the peroxy acid generated according to the invention is formed using between about 0.1% and about 5% by weight of the nitrogenous compound, based on the total weight of the aqueous composition.
[0039] Also provided herein are processes for disinfecting various microbes, including bacteria, molds, fungi and their spores, from various articles and surfaces, which processes comprise generating an aqueous solution which contains a peroxy acid as described herein, and subsequently directing the vapor of the peroxy acid that is evolved from a solution so generated to a surface or article (including without limitation articles such as surgical implements and other medical equipment or wares) using conventional means of vaporization and direction, which may be selected from the group consisting of: heat, venturi nebulization, and sonication. Blowers and fans and other air or gas circulating equipment known to those skilled in the art may be beneficially employed. For purposes of this specification and claims, the word “surface” means any surface of any solid object, and includes without limitation walls, floors, ceilings, surgical instruments, medical wares, machinery, equipment, facilities, dwellings, garments, motorized vehicles, aircraft, windows, plumbing, corridors, etc.
[0040] Thus, in some embodiments, the mixing of the water, nitrogenous compound, and source of peroxide is conducted under conditions which enable evolution of vapors of peroxy acid so generated from the aqueous solution so formed by such mixing. Such conditions may be ambient conditions of standard temperature (298° K.) and pressure (1 atm), or may include elevated temperatures and reduced pressures. Typically, such vapors will contain some co-volatilized water. In some process embodiments involving the contacting of a surface or implement that is to be disinfected with an aqueous composition as taught herein, the contacting is accomplished byhaving the aqueous composition comprise a mixture of water vapor and the peroxy acid liberated by the solution formed from the mixing as provided herein. Stated another way, a surface or implement may be disinfected by contacting the subject surface or implement with a vapor that comprises a peroxy acid provided herein, with water being optionally present in such vapor in any amount between about 1% and 75% by partial pressure of such vapor.
[0041] Consideration must be given to the fact that although this invention has been described and disclosed in relation to certain preferred embodiments, obvious equivalent modifications and alterations thereof will become apparent to one of ordinary skill in this art upon reading and understanding this specification and the claims appended hereto. The present invention further includes all possible combinations of the features recited in the specification and/or any one of the various claims appended hereto with the features recited elsewhere in the specification and/or in any one or more of each of the remaining claims. For example, the present specification includes disclosure of a process according to claim 18 which comprises contacting a composition according to any of claims 1 - 17 with an aqueous peroxide. Accordingly, the presently disclosed invention is intended to cover all such modifications, alterations, and combinations.
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This present invention provides materials for use as solid or concentrated chemical precursors for the production of organic peroxy acids (peracids). Organic peroxy acids are formed using a precursor according to the invention when they are combined with hydrogen peroxide or a hydrogen peroxide precursor such as a percarbonate or a perborate in aqueous medium. Organic peroxy acids, such as peroxyacetic acid, are used currently to disinfect medical equipment such as endoscopes and related items.
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BACKGROUND OF THE INVENTION
The extreme weakness of doors in modern day homes and other buildings making them unable to resist forceable entry to any reasonable degree is a very serious and widely recognized concern or problem. Even in costly homes, a shoulder against the door or a stout kick with the foot will open it when locked or bolted. If the door panel itself is made strong, the door will still yield due to the inherent weakness of the jamb structure and the mounting of the striker plate which is relied upon to interlock with the bolt. The use of a strong lock and lock bolt is of no avail so long as the inherent weak arrangement of jamb and striker plate mounting is adhered to.
The problem has been recognized in the prior art and solutions to it have been proposed. One example of a patented prior art solution is disclosed in U.S. Pat. No. 3,764,173, issued Oct. 9, l973 to Griffith. While Griffith successfully reinforces the usual striker plate and associated jamb, he does so with a rather large and complex plate attachment which spans the entire door frame and constitutes an unsightly and unacceptable element to most home owners. In comparison to the Griffith solution, the present invention successfully strengthens or reinforces the vital striker plate structure without changing or detracting from the conventional uncluttered appearance of the door frame and adjacent structure. The reinforcing plate forming the main element of the invention is concealed beneath the conventional striker plate during use and also concealed by an overlapping part of an attendant seal or weather strip.
Other aspects and advantages of the invention will become apparent during the course of the following description.
BRIEF DESCRIPTION OF DRAWING FIGURES
FIG. 1 is a perspective view of a striker plate reinforcement according to the invention.
FIG. 2 is a further perspective view thereof.
FIG. 3 is an exploded side elevational view of the invention in relation to a door frame which has been prepared to accept the invention.
FIG. 4 is an enlarged fragmentary horizontal section through a door jamb and door utilizing the invention and taken through the jamb on line 4--4 of FIG. 3.
DETAILED DESCRIPTION
Referring to the drawings in detail, wherein like numerals designate like parts, reference is made first to FIG. 3 showing a fragment of one side of a vertical door jamb 10 having a stop rail 11 suitably attached thereto, with a weather strip or seal 12 formed of plastic or the like held within a recess between the stop rail and jamb and projecting forwardly thereof as shown in both FIGS. 3 and 4.
The door jamb 10 is routed in two rectangular areas 14 to accept two units of the invention in cases where a door 15, FIG. 4, has primary and secondary locks at two vertical elevations, as is quite common. In other cases, where only a primary lock is utilized, one of the routed recesses 14 will not be used and only one unit of the invention need be employed as illustrated in the drawings. In such a case, the upper routed recess 14 of the door jamb can be neatly covered and concealed beneath an identification tag 16 which may bear a trademark used on the invention or other desirable advertising indicia. The tag or plate 16 may be formed of molded nylon or the like of a sufficient thickness to fill the unused recess 14 when mounted therein adhesively or otherwise. The rear portion of the unused recess will be overlapped and concealed by the projecting portion of the weather strip 12.
Since each unit of the invention will be identical with other units, a complete description of one unit will be sufficient to describe the invention. Such unit, now to be described, will be mounted in the lower routed recess 14 of the door frame as shown in FIG. 3. The recess 14 is sufficiently deep to accommodate both the reinforcement plate 17 of the invention and the conventional striker plate 18 applied to the outer face of the reinforcement plate as shown in the drawings.
The reinforcement plate 17, forming the key element of the invention, embodies a rectangular body portion 19 formed to fit into the recess 14 and having a central rectangular opening 20 to register in assembly with the usual door lock bolt receiving socket 21 formed in the door jamb. At the forward and rear sides of the opening 20, plate body portion 19 carries integral rigid right angular anchoring and alignment tabs 22 which enter the socket recess 21 and lie against its forward and rear side walls, as best shown in FIG. 4. These tabs in addition to aligning the reinforcement plate 17 lock the same against fore and aft displacement relative to the door jamb.
The reinforcement plate 17 further embodies a reduced width rearward tongue 23 having a short inturned flange 24. This tongue and flange portion of the reinforcement plate is received in the rearward part of routed recess 14.
The reinforcement plate 17 is additionally provided on opposite sides of the tongue 23 with sturdy prongs 25 which are initially raised from the plane of the body portion 19 prior to the mounting of the invention. When the reinforcement plate is mounted, FIGS. 3 and 4, the prongs are driven down with a hammer so that their right angular pointed portions penetrate the door jamb 10 and lie at right angles to the plate body portion 19 as clearly shown in FIG. 4. These prongs further anchor and stabilize the reinforcement plate on the jamb to prevent its dislodgement during an attempted forceable entry through the door by an intruder.
Above and below the opening 20, reinforcement plate 17 has a pair of apertures 26 for screws 27 which pass well into the door frame 10 above and below bolt socket 21. A third aperture 28 rearward from the apertures 26 and midway therebetween is formed through the tongue 23 and accepts a third long screw 29. Thus, the reinforcement plate is further anchored to the door jamb by the two described screws 27, and the third long screw 29, which passes through the door jamb and penetrates the adjacent wall stud 29', inwardly of the shim 30'.
The conventional striker plate 18 shown separated in FIG. 3 is applied to the outer side of reinforcement plate 17 and is flush with the door jamb surface. It has a central opening 30 to accept the door bolt 31 and is in registry with the socket 21 and the opening 20 of the reinforcement plate when the parts are assembled as in FIG. 4. The striker plate 18 has apertures 32 above and below the opening 30 which receive the two screws 27 to be anchored thereby.
It may now be noted that when the invention is assembled to the door frame, its appearance is conventional and no unsightly attachments are visible to an observer. The rearward elements 25 and 23 are concealed beneath the projecting part of weather strip 12. The remainder of the reinforcement plate 17 is covered and concealed by conventonal striker plate 18. Nevertheless, the invention greatly improves and multiplies the strength and resistance of the door to foreceable entry. If the door 15 and its lock are of sturdy construction, it will be impossible for an intruder by means of his shoulder or other physical force to effect a forceable entry because the reinforced striker plate in coaction with the bolt 31 will resist this. In contrast, with weak conventional structures, the intruder is able to force the door with little difficulty, breaking off the stop rail 11 and ripping the weakly anchored striker plate from the door jamb. Another advantage of the invention is that it is completely compatible with conventional door hardware of many makers, requires no modification of standard or existing locks and does not interfere in any way with the normal use or operation of these components. The many advantages of the construction should now be apparent to those skilled in the art.
As shown, the entire extension or tongue 23 is slightly offset in a plane parallel to the body portion 19 and this offset construction forms a shoulder 33 between the elements 19 and 23. The numeral 34 denotes a recess in the stop rail 11.
It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention or scope of the subjoined claims.
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A metal reinforcing plate is arranged beneath the usual striker plate in a routed recess of the wooden door jamb. The reinforcing plate has integral anchoring prongs which are driven into the wooden jamb immediately ahead of the stop rail and has additional anchoring and locator tabs which are received at the side walls of the bolt receiving recess or socket in the door jamb. The reinforcing plate is substantially concealed from view while imparting to the door structure substantial extra strength against forceable entry.
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[0001] This application is a Continuation of U.S. patent application Ser. No. 11/568,015, filed on Oct. 17, 2006, which is a National Stage of PCT/JP2005/015460, filed on Aug. 25, 2005, which claims priority to Japanese Application No. 2004-249011 filed on Aug. 27, 2004. The entire disclosures of the prior applications are hereby incorporated herein by reference in their entirety.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates to a technique for reducing vibration in a reciprocating power tool, such as a hammer and a hammer drill, which linearly drives a tool bit.
[0004] 2. Background of the Invention
[0005] Japanese non-examined laid-open Patent Publication No. 52-109673 discloses an electric hammer having a vibration reducing device. In the known electric hammer, a vibration proof chamber is integrally formed with a body housing (and a motor housing) in a region on the lower side of the body housing and forward of the motor housing. A dynamic vibration reducer is disposed within the vibration proof chamber.
[0006] In the above-mentioned known electric hammer, the vibration proof chamber that houses the dynamic vibration reducer is provided in the housing in order to provide an additional function of reducing vibration in working operation. As a result, however, the electric hammer increases in size.
SUMMARY
Object of the Invention
[0007] It is, accordingly, an object of the present invention to provide an effective technique for reducing vibration in working operation, while avoiding size increase of a power tool.
Subject Matter of the Invention
[0008] The above-described object is achieved by the features of claimed invention. The invention provides a power tool which includes a motor, an internal mechanism driven by the motor, a housing that houses the motor and the internal mechanism, a tool bit disposed in one end of the housing and driven by the internal mechanism in its longitudinal direction to thereby perform a predetermined operation, a handgrip connected to the other end of the housing, and a dynamic vibration reducer including a weight and an elastic element. The elastic element is disposed between the weight and the housing and adapted to apply a biasing force to the weight. The weight reciprocates in the longitudinal direction of the tool bit against the biasing force of the elastic element. By the reciprocating movement of the weight, the dynamic vibration reducer reduces vibration which is caused in the housing in the longitudinal direction of the tool bit in the working operation.
[0009] The “power tool” may particularly includes power tools, such as a hammer, a hammer drill, a jigsaw and a reciprocating saw, in which a tool bit performs a working operation on a workpiece by reciprocating. When the power tool is a hammer or a hammer drill, the “internal mechanism” according to this invention comprises a motion converting mechanism that converts the rotating output of the motor to linear motion and drives the tool bit in its longitudinal direction, and a power transmitting mechanism that appropriately reduces the speed of the rotating output of the motor and transmits the rotating output as rotation to the tool bit.
[0010] In the present invention, the dynamic vibration reducer is disposed in the power tool by utilizing a space within the housing and/or the handgrip. Therefore, the dynamic vibration reducer can perform a vibration reducing action in working operation, while avoiding size increase of the power tool. Further, the dynamic vibration reducer can be protected from an outside impact, for example, in the event of drop of the power tool. The manner in which the dynamic vibration reducer is “disposed by utilizing a space between the housing and the internal mechanism” includes not only the manner in which the dynamic vibration reducer is disposed by utilizing the space as-is, but also the manner in which it is disposed by utilizing the space changed in shape.
[0011] The present invention will be more apparent from the following detailed description and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1A is a side view showing a hammer drill according to an embodiment of the invention, with an outer housing and an inner housing shown in section;
[0013] FIG. 1B is a side view showing a hammer drill according to another embodiment of the invention, with an outer housing and an inner housing shown in section;
[0014] FIG. 2A is a side view of the hammer drill, with the outer housing shown in section according to an embodiment of the invention;
[0015] FIG. 2B is a side view of the hammer drill, with the outer housing shown in section according to another embodiment of the invention;
[0016] FIG. 2C is a side view of the hammer drill, with the outer housing shown in section according to another embodiment of the invention;
[0017] FIG. 2D is a side view of the hammer drill, with the outer housing shown in section according to another embodiment of the invention;
[0018] FIG. 2E is a side view of the hammer drill, with the outer housing shown in section according to another embodiment of the invention;
[0019] FIG. 2F is a side view of the hammer drill, with the outer housing shown in section according to another embodiment of the invention;
[0020] FIG. 3 is a plan view of the hammer drill, with the outer housing shown in section;
[0021] FIG. 4 is a plan view of the hammer drill, with the outer housing shown in section;
[0022] FIG. 5 is a rear view of the hammer drill, with the outer housing shown in section;
[0023] FIG. 6 is a sectional view taken along line A-A in FIG. 1A ; and
[0024] FIG. 7 is a sectional view taken along line B-B in FIG. 1B .
DETAILED DESCRIPTION OF EMBODIMENTS
[0025] Representative embodiments of the present invention will now be described with reference to FIGS. 1A to 7 . In each embodiment, an electric hammer drill will be explained as a representative example of a power tool according to the present invention. Each of the embodiments features a dynamic vibration reducer disposed in a space within a housing or a handgrip. Before a detailed explanation of placement of the dynamic vibration reducer, the configuration of the hammer drill will be briefly described with reference to FIG. 1A . The hammer drill 101 mainly includes a body 103 , a hammer bit 119 detachably coupled to the tip end region (on the left side as viewed in FIG. 1A ) of the body 103 via a tool holder 137 , and a handgrip 102 connected to a region of the body 103 on the opposite side of the hammer bit 119 . The body 103 , the hammer bit 119 and the handgrip 102 are features that correspond to the “housing”, the “tool bit” and the “handgrip”, respectively, according to the present invention.
[0026] The body 103 of the hammer drill 101 mainly includes a motor housing 105 , a crank housing 107 , and an inner housing 109 that is housed within the motor housing 105 and the crank housing 107 . The motor housing 105 and the crank housing 107 are features that correspond to the “outer housing” according to this invention, and the inner housing 109 corresponds to the “inner housing”. The motor housing 105 is located on the lower part of the handgrip 102 toward the front and houses a driving motor 111 . The driving motor 111 is a feature that corresponds to the “motor” according to this invention.
[0027] In the present embodiments, for the sake of convenience of explanation, in the state of use in which the user holds the handgrip 102 , the side of the hammer bit 119 is taken as the front side and the side of the handgrip 102 as the rear side. Further, the side of the driving motor 111 is taken as the lower side and the opposite side as the upper side; the vertical direction and the horizontal direction which are perpendicular to the longitudinal direction are taken as the vertical direction and the lateral direction, respectively.
[0028] The crank housing 107 is located on the upper part of the handgrip 102 toward the front and butt-joined to the motor housing 105 from above. The crank housing 107 houses the inner housing 109 together with the motor housing 105 . The inner housing 109 houses a cylinder 141 , a motion converting mechanism 113 , and a gear-type power transmitting mechanism 117 . The cylinder 141 houses a striking element 115 that is driven to apply a striking force to the hammer bit 119 in its longitudinal direction. The motion converting mechanism 113 comprises a crank mechanism and converts the rotating output of the driving motor 111 to linear motion and then drives the striking element 115 via an air spring. The power transmitting mechanism 117 transmits the rotating output of the driving motor 111 as rotation to the hammer bit 119 via a tool holder 137 . Further, the inner housing 109 includes an upper housing 109 a and a lower housing 109 b . The upper housing 109 a houses the entire cylinder 141 and most of the motion converting mechanism 113 and power transmitting mechanism 117 , while the lower housing 109 b houses the rest of the motion converting mechanism 113 and power transmitting mechanism 117 . The motion converting mechanism 113 , the striking element 115 and the power transmitting mechanism 117 are features that correspond to the “internal mechanism” according to this invention.
[0029] The motion converting mechanism 113 appropriately converts the rotating output of the driving motor 111 to linear motion and then transmits it to the striking element 115 . As a result, an impact force is generated in the longitudinal direction of the hammer bit 119 via the striking element 115 . The striking element 115 includes a striker 115 a and an intermediate element in the form of an impact bolt (not shown). The striker 115 a is driven by the sliding movement of a piston 113 a of the motion converting mechanism 113 via the action of air spring within the cylinder 141 . Further, the power transmitting mechanism 117 appropriately reduces the speed of the rotating output of the driving motor 111 and transmits the rotating output as rotation to the hammer bit 119 . Thus, the hammer bit 119 is caused to rotate in its circumferential direction. The hammer drill 101 can be switched by appropriate operation of the user between a hammer mode in which a working operation is performed on a workpiece by applying only a striking force to the hammer bit 119 in the longitudinal direction, and a hammer drill mode in which a working operation is performed on a workpiece by applying an longitudinal striking force and a circumferential rotating force to the hammer bit 119 .
[0030] The hammering operation in which a striking force is applied to the hammer bit 119 in the longitudinal direction by the motion converting mechanism 113 and the striking element 115 , and the hammer-drill operation in which a rotating force is applied to the hammer bit 119 in the circumferential direction by the power transmitting mechanism 117 in addition to the striking force in the longitudinal direction are known in the art. Also, the mode change between the hammer mode and the hammer drill mode is known in the art. These known techniques are not directly related to this invention and therefore will not be described in further detail.
[0031] The hammer bit 119 moves in the longitudinal direction on the axis of the cylinder 141 . Further, the driving motor 111 is disposed such that the axis of an output shaft 111 a is perpendicular to the axis of the cylinder 141 . The inner housing 109 is disposed above the driving motor 111 .
[0032] The handgrip 102 includes a grip 102 a to be held by the user and an upper and a lower connecting portions 102 b , 102 c that connect the grip 102 a to the rear end of the body 103 . The grip 102 a vertically extends and is opposed to the rear end of the body 103 with a predetermined spacing. In this state, the grip 102 a is detachably connected to the rear end of the body 103 via the upper and lower connecting portions 102 b , 102 c.
[0033] A dynamic vibration reducer 151 is provided in the hammer drill 101 in order to reduce vibration which is caused in the hammer drill 101 , particularly in the longitudinal direction of the hammer bit 119 , during hammering or hammer-drill operation. The dynamic vibration reducer 151 is shown as an example in FIGS. 2A-2F and 3 in sectional view. The dynamic vibration reducer 151 mainly includes a box-like (or cylindrical) vibration reducer body 153 , a weight 155 and biasing springs 157 disposed on the front and rear sides of the weight 155 . The weight 155 is disposed within the vibration reducer body 153 and can move in the longitudinal direction of the vibration reducer body 153 . The biasing spring 157 is a feature that corresponds to the “elastic element” according to the present invention. The biasing spring 157 applies a spring force to the weight 155 when the weight 155 moves in the longitudinal direction of the vibration reducer body 153 .
[0034] Placement of the dynamic vibration reducer 151 will now be explained with respect to each embodiment.
First Embodiment
[0035] In the first embodiment, as shown in FIGS. 2A and 3 , the dynamic vibration reducer 151 is disposed by utilizing a space in the upper region inside the body 103 , or more specifically, a space 201 existing between the inner wall surface of the upper region of the crank housing 107 and the outer wall surface of the upper region of an upper housing 109 a of the inner housing 109 . The dynamic vibration reducer 151 is disposed in the space 201 such that the direction of movement of the weight 155 or the vibration reducing direction coincides with the longitudinal direction of the hammer bit 119 . The space 201 is dimensioned to be larger in the horizontal directions (the longitudinal and lateral directions) than in the vertical direction (the direction of the height). Therefore, in this embodiment, the dynamic vibration reducer 151 has a shape conforming to the space 201 . Specifically, as shown in sectional view, the vibration reducer body 153 has a box-like shape short in the vertical direction and long in the longitudinal direction. Further, projections 159 are formed on the right and left sides of the weight 155 in the middle in the longitudinal direction. The biasing springs 157 are disposed between the projections 159 and the front end and the rear end of the vibration reducer body 153 . Thus, the amount of travel of the weight 155 can be maximized while the longitudinal length of the vibration reducer body 153 can be minimized. Further, the movement of the weight 155 can be stabilized.
[0036] Thus, in the first embodiment, the dynamic vibration reducer 151 is disposed by utilizing the space 201 existing within the body 103 . As a result, vibration caused in working operation of the hammer drill 101 can be reduced by the vibration reducing action of the dynamic vibration reducer 151 , while size increase of the body 103 can be avoided. Further, by placement of the dynamic vibration reducer 151 within the body 103 , the dynamic vibration reducer 151 can be protected from an outside impact in the event of drop of the hammer drill 101 .
[0037] As shown in FIG. 2A , generally, a center of gravity G of the hammer drill 101 is located below the axis of the cylinder 141 and slightly forward of the axis of the driving motor 111 . Therefore, when, like this embodiment, the dynamic vibration reducer 151 is disposed within the space 201 existing between the inner wall surface of the upper region of the crank housing 107 and the outer wall surface of the upper region of the upper housing 109 a of the inner housing 109 , the dynamic vibration reducer 151 is disposed on the side of the axis of the cylinder 141 which is opposite to the center of gravity G of the hammer drill 101 . Thus, the center of gravity G of the hammer drill 101 is located closer to the axis of the cylinder 141 , which is effective in lessening or preventing vibration in the vertical direction. Further, the dynamic vibration reducer 151 disposed in the space 201 is located relatively near to the axis of the cylinder 141 , so that it can perform an effective vibration reducing action against vibration in working operation using the hammer drill 101 .
Second Embodiment
[0038] In the second representative embodiment, as shown in FIGS. 2B and 5 , a dynamic vibration reducer 213 is disposed by utilizing a space in the side regions toward the upper portion within the body 103 , or more specifically, right and left spaces 211 existing between the right and left inner wall surfaces of the side regions of the crank housing 107 and the right and left outer wall surfaces of the side regions of the upper housing 109 a . The spaces 211 correspond to the lower region of the cylinder 141 and extend in a direction parallel to the axis of the cylinder 141 or the longitudinal direction of the cylinder 141 . Therefore, in this case, as shown by dashed lines in FIGS. 2B and 5 , the dynamic vibration reducer 213 has a cylindrical shape and is disposed such that the direction of movement of the weight or the vibration reducing direction coincides with the longitudinal direction of the hammer bit 119 . The dynamic vibration reducer 213 is the same as the first embodiment in the construction, except for the shape, including a body, a weight and biasing springs, which are not shown.
[0039] According to the second embodiment, in which the dynamic vibration reducer 213 is placed in the right and left spaces 211 existing between the right and left inner wall surfaces of the side region of the crank housing 107 and the right and left outer wall surfaces of the side region of the upper housing 109 a , like the first embodiment, the dynamic vibration reducer 213 can perform the vibration reducing action in working operation of the hammer drill 101 , while avoiding size increase of the body 103 . Further, the dynamic vibration reducer 213 can be protected from an outside impact in the event of drop of the hammer drill 101 . Especially in the second embodiment, the dynamic vibration reducer 213 is disposed in a side recess 109 c of the upper housing 109 a , so that the amount of protrusion of the dynamic vibration reducer 213 from the side of the upper housing 109 a can be lessened. Therefore, high protection can be provided against an outside impact. The upper housing 109 a is shaped to minimize the clearance between the mechanism component parts within the upper housing 109 a and the inner wall surface of the upper housing 109 a . To this end, the side recess 109 c is formed in the upper housing 109 a . Specifically, due to the positional relationship between the cylinder 141 and a driving gear of the motion converting mechanism 113 or the power transmitting mechanism 117 which is located below the cylinder 141 , the side recess 109 c is defined as a recess formed in the side surface of the upper housing 109 a and extending in the axial direction of the cylinder 141 . The side recess 109 c is a feature that corresponds to the “recess” according to this invention.
[0040] Further, in the second embodiment, the dynamic vibration reducer 213 is placed very close to the center of gravity G of the hammer drill 101 as described above. Therefore, even with a provision of the dynamic vibration reducer 213 in this position, the hammer drill 101 can be held in good balance of weight in the vertical and horizontal directions perpendicular to the longitudinal direction of the hammer bit 119 , so that generation of vibration in these vertical and horizontal directions can be effectively lessened or prevented. Moreover, the dynamic vibration reducer 213 is placed relatively close to the axis of the cylinder 141 , so that it can perform an effective vibration reducing function against vibration input in working operation of the hammer drill 101 .
[0041] As shown in FIGS. 2B and 5 , the hammer drill 101 having the driving motor 111 includes a cooling fan 121 for cooling the driving motor 111 . When the cooling fan 121 is rotated, cooling air is taken in through inlets 125 of a cover 123 that covers the rear surface of the body 103 . The cooling air is then led upward within the motor housing 105 and cools the driving motor 111 . Thereafter, the cooling air is discharged to the outside through an outlet 105 a formed in the bottom of the motor housing 105 . Such a flow of the cooling air can be relatively easily guided into the region of the dynamic vibration reducer 213 . Thus, according to the second embodiment, the dynamic vibration reducer 213 can be advantageously cooled by utilizing the cooling air for the driving motor 111 .
[0042] Further, in the hammer drill 101 , when the motion converting mechanism 113 in the inner housing 109 is driven, the pressure within a crank chamber 127 (see FIGS. 1A and 1B ) which comprises a hermetic space surrounded by the inner housing 109 fluctuates (by linear movement of the piston 113 a within the cylinder 141 shown in FIGS. 1A AND 1B ). By utilizing the pressure fluctuations, a forced vibration method may be used in which a weight is positively driven by introducing the fluctuating pressure into the body of the dynamic vibration reducer 213 . In this case, according to the second embodiment, with the construction in which the dynamic vibration reducer 213 is placed adjacent to the inner housing 109 that houses the motion converting mechanism 113 , the fluctuating pressure in the crank chamber 127 can be readily introduced into the dynamic vibration reducer 213 . Further, when, for example, the motion converting mechanism 113 comprises a crank mechanism as shown in FIGS. 1A AND 1B , the construction for forced vibration of a weight of the dynamic vibration reducer 213 can be readily provided by providing an eccentric portion in the crank shaft. Specifically, the eccentric rotation of the eccentric portion is converted into linear motion and inputted as a driving force of the weight in the dynamic vibration reducer 213 , so that the weight is forced vibrated.
Third Embodiment
[0043] In the third representative embodiment, as shown in FIGS. 2C and 5 , a dynamic vibration reducer 223 is disposed by utilizing a space in the side regions within the body 103 , or more specifically, a space 221 existing between one axial end (upper end) of the driving motor 111 and the bottom portion of the lower housing 107 b and extending along the axis of the cylinder 141 (in the longitudinal direction of the hammer bit 119 ). The space 221 extends in a direction parallel to the axis of the cylinder 141 , or in the longitudinal direction. Therefore, in this case, as shown by dashed line in FIGS. 2C and 5 , the dynamic vibration reducer 223 has a cylindrical shape and is disposed such that the direction of movement of the weight or the vibration reducing direction coincides with the longitudinal direction of the hammer bit 119 . The dynamic vibration reducer 213 is the same as the first embodiment in the construction, except for the shape, including a body, a weight and biasing springs, which are not shown.
[0044] According to the third embodiment, in which the dynamic vibration reducer 223 is placed in the space 221 existing between one axial end (upper end) of the driving motor 111 and the lower housing 107 b , like the first and second embodiments, the dynamic vibration reducer 223 can perform the vibration reducing action in working operation of the hammer drill 101 , while avoiding size increase of the body 103 . Further, the dynamic vibration reducer 223 can be protected from an outside impact in the event of drop of the hammer drill 101 .
[0045] In the third embodiment, the dynamic vibration reducer 223 is located close to the center of gravity G of the hammer drill 101 like the second embodiment and adjacent to the driving motor 111 . Therefore, like the second embodiment, even with a provision of the dynamic vibration reducer 223 in this position, the hammer drill 101 can be held in good balance of weight in the vertical and horizontal directions perpendicular to the longitudinal direction of the hammer bit 119 . Moreover, a further cooling effect can be obtained especially because the dynamic vibration reducer 223 is located in the passage of the cooling air for cooling the driving motor 111 . Further, although the dynamic vibration reducer 223 is located at a slight more distance from the crank chamber 127 compared with the second embodiment, the forced vibration method can be relatively easily realized in which a weight is positively driven by introducing the fluctuating pressure of the crank chamber into the dynamic vibration reducer 223 .
Fourth Embodiment
[0046] In the fourth representative embodiment, as shown in FIGS. 2D and 4 , a dynamic vibration reducer 233 is disposed by utilizing a space existing in the right and left side upper regions within the body 103 , or more specifically, a space 231 existing between the right and left inner wall surfaces of the side regions of the crank housing 107 and the right and left outer wall surfaces of the side regions of the upper housing 109 a of the inner housing 109 . The space 231 is relatively limited in lateral width due to the narrow clearance between the inner wall surfaces of the crank housing 107 and the outer wall surfaces of the upper housing 109 a , but it is relatively wide in the longitudinal and vertical directions. Therefore, in this embodiment, the dynamic vibration reducer 233 has a shape conforming to the space 231 . Specifically, as shown by dashed line in FIGS. 2D and 4 , the dynamic vibration reducer 233 has a box-like shape short in the lateral direction and long in the longitudinal and vertical directions and is disposed such that the direction of movement of the weight or the vibration reducing direction coincides with the longitudinal direction of the hammer bit 119 . The dynamic vibration reducer 233 is the same as the first embodiment in the construction, except for the shape, including a body, a weight and biasing springs, which are not shown.
[0047] According to the fourth embodiment, in which the dynamic vibration reducer 233 is placed in the space 231 existing between the right and left inner wall surfaces of the side regions of the crank housing 107 and the right and left outer wall surfaces of the side regions of the upper housing 109 a of the inner housing 109 , like the above-described embodiments, the dynamic vibration reducer 233 can perform the vibration reducing action in working operation of the hammer drill 101 , while avoiding size increase of the body 103 . Further, the dynamic vibration reducer 233 can be protected from an outside impact in the event of drop of the hammer drill 101 . Especially, the dynamic vibration reducer 233 of the fourth embodiment occupies generally the entirety of the space 231 existing between the inner wall surfaces of the side regions of the crank housing 107 and the outer wall surfaces of the side regions of the upper housing 109 a . The dynamic vibration reducer 233 in the space 231 is located closest to the axis of the cylinder 141 among the above-described embodiments, so that it can perform a more effective vibration reducing action against vibration input in working operation of the hammer drill 101 .
Fifth Embodiment
[0048] In the fifth representative embodiment, as shown in FIGS. 1A and 6 , a dynamic vibration reducer 243 is disposed in a space existing inside the body 103 , or more specifically, in the crank chamber 127 which comprises a hermetic space within the inner housing 109 that houses the motion converting mechanism 113 and the power transmitting mechanism 117 . More specifically, as shown by dotted line in FIG. 1A , the dynamic vibration reducer 243 is disposed in the vicinity of the joint between the upper housing 109 a and the lower housing 109 b of the inner housing 109 by utilizing a space 241 existing between the inner wall surface of the inner housing 109 and the motion converting mechanism 113 and power transmitting mechanism 117 within the inner housing 109 . The dynamic vibration reducer 243 is disposed such that the vibration reducing direction coincides with the longitudinal direction of the hammer bit 119 .
[0049] In order to dispose the dynamic vibration reducer 243 in the space 241 , as shown in FIG. 6 in sectional view, a body 245 of the dynamic vibration reducer 243 is formed into an oval (elliptical) shape in plan view which conforms to the shape of the inner wall surface of the upper housing 109 a of the inner housing 109 . A weight 247 is disposed within the vibration reducer body 245 and has a generally horseshoe-like shape in plan view. The weight 247 is disposed for sliding contact with a crank shaft 113 b of the motion converting mechanism 113 and a gear shaft 117 a of the power transmitting mechanism 117 in such a manner as to pinch them from the both sides. Thus, the weight 247 can move in the longitudinal direction (in the axial direction of the cylinder 141 ). Specifically, the crank shaft 113 b and the gear shaft 117 a are utilized as a member for guiding the movement of the weight 247 in the longitudinal direction. Projections 248 are formed on the right and left sides of the weight 247 , and the biasing springs 249 are disposed on the opposed sides of the projections 248 . Specifically, the biasing springs 249 connect the weight 247 to the vibration reducer body 243 . When the weight 247 moves in the longitudinal direction of the vibration reducer body 243 (in the axial direction of the cylinder 141 ), the biasing springs 249 apply a spring force to the weight 247 in the opposite direction.
[0050] According to the fifth embodiment, in which the dynamic vibration reducer 243 is placed in the space 241 existing within the inner housing 109 , like the above-described embodiments, the dynamic vibration reducer 243 can perform the vibration reducing action in working operation of the hammer drill 101 , while avoiding size increase of the body 103 . Further, the dynamic vibration reducer 243 can be protected from an outside impact in the event of drop of the hammer drill 101 .
[0051] Further, in the fifth embodiment, the dynamic vibration reducer 243 is placed very close to the center of gravity G of the hammer drill 101 as described above. Therefore, even with a provision of the dynamic vibration reducer 243 in such a position, as explained in the second embodiment, the hammer drill 101 can be held in good balance of weight in the vertical and horizontal directions perpendicular to the longitudinal direction of the hammer bit 119 , so that generation of vibration in these vertical and horizontal directions can be effectively lessened or prevented. Moreover, the dynamic vibration reducer 243 is placed relatively close to the axis of the cylinder 141 , so that it can effectively perform a vibration reducing function against vibration caused in the axial direction of the cylinder 141 in working operation of the hammer drill 101 . Further, the space surrounded by the inner housing 109 forms the crank chamber 127 . Thus, with the construction in which the dynamic vibration reducer 243 is disposed within the crank chamber 127 , when the forced vibration method is used in which the weight 247 of the dynamic vibration reducer 243 is forced to vibrate by utilizing the pressure fluctuations of the crank chamber 127 , the crank chamber 127 can be readily connected to the space of the body 245 of the dynamic vibration reducer 243 .
Sixth Embodiment
[0052] In the sixth representative embodiment, as shown in FIGS. 1B and 7 , a dynamic vibration reducer 253 is placed by utilizing a space existing inside the body 103 , or more specifically, a space 251 existing in the upper portion of the motor housing 105 . Therefore, the sixth embodiment can be referred to as a modification of the second embodiment. In the sixth embodiment, as shown by dotted line in FIG. 1B , the dynamic vibration reducer 243 is disposed by utilizing the space 251 between the upper end of the rotor 111 b of the driving motor 111 and the underside of the lower housing 109 b of the inner housing 109 . To this end, as shown in FIG. 7 , a body 255 of the dynamic vibration reducer 253 is formed into an oval (elliptical) shape in sectional plan view, and a weight 257 is formed into a generally elliptical ring-like shape in plan view. The weight 257 is disposed for sliding contact with bearing receivers 131 a and 133 a in such a manner as to pinch them from the both sides and can move in the longitudinal direction (in the axial direction of the cylinder 141 ). The bearing receiver 131 a receives a bearing 131 that rotatably supports the output shaft 111 a of the driving motor 111 , and the bearing receiver 133 a receives a bearing 133 that rotatably supports the gear shaft 117 a of the motion converting mechanism 117 . The bearing receivers 131 a and 133 a are also utilized as a member for guiding the movement of the weight 257 in the longitudinal direction. Further, projections 258 are formed on the right and left sides of the weight 257 , and the biasing springs 259 are disposed on the opposed sides of the projections 258 . Specifically, the biasing springs 259 connect the weight 257 to the vibration reducer body 253 . When the weight 257 moves in the longitudinal direction of the vibration reducer body 253 (in the axial direction of the cylinder 141 ), the biasing springs 259 apply a spring force to the weight 257 in the opposite direction.
[0053] According to the sixth embodiment, in which the dynamic vibration reducer 253 is placed in the space 251 existing within the motor housing 105 , like the above-described embodiments, the dynamic vibration reducer 253 can perform the vibration reducing action in the working operation of the hammer drill 101 , while avoiding size increase of the body 103 . Further, the dynamic vibration reducer 253 can be protected from an outside impact in the event of drop of the hammer drill 101 .
[0054] Further, in the sixth embodiment, the dynamic vibration reducer 253 is placed close to the center of gravity G of the hammer drill 101 as described above. Therefore, even with a provision of the dynamic vibration reducer 243 in such a position, as explained in the second embodiment, the hammer drill 101 can be held in good balance of weight in the vertical and horizontal directions perpendicular to the longitudinal direction of the hammer bit 119 , so that generation of vibration in these vertical and horizontal directions can be effectively lessened or prevented. Further, the lower position of the lower housing 109 b is very close to the crank chamber 127 . Therefore, when the method of causing forced vibration of the dynamic vibration reducer 253 is applied, the fluctuating pressure in the crank chamber 127 can be readily introduced into the dynamic vibration reducer 253 . Moreover, the construction for causing forced vibration of the weight 257 can be readily provided by providing an eccentric portion in the crank shaft 113 b of the motion converting mechanism 113 . Specifically, the eccentric rotation of the eccentric portion is converted into linear motion and inputted as a driving force of the weight 257 in the dynamic vibration reducer 253 , so that the weight 257 is forced vibrated.
Seventh Embodiment
[0055] In the seventh representative embodiment, as shown in FIGS. 2E to 4 , a dynamic vibration reducer 263 is disposed by utilizing a space existing inside the handgrip 102 . As described above, the handgrip 102 includes a grip 102 a to be held by the user and an upper and a lower connecting portions 102 b , 102 c that connect the grip 102 a to the body 103 . The upper connecting portion 102 b is hollow and extends to the body 103 . In the seventh embodiment, a dynamic vibration reducer 263 is disposed in a space 261 existing within the upper connecting portion 102 b and extending in the longitudinal direction (in the axial direction of the cylinder 141 ). As shown by dotted line in FIGS. 2E to 4 , the dynamic vibration reducer 263 has a rectangular shape elongated in the longitudinal direction. The dynamic vibration reducer 263 is the same as the first embodiment in the construction, except for the shape, including a body, a weight and biasing springs, which are not shown.
[0056] According to the seventh embodiment, in which the dynamic vibration reducer 263 is disposed in the space 261 existing inside the handgrip 102 , like the above-described embodiments, the dynamic vibration reducer 263 can perform the vibration reducing action in working operation of the hammer drill 101 , while avoiding size increase of the body 103 . Further, the dynamic vibration reducer 263 can be protected from an outside impact in the event of drop of the hammer drill 101 . Especially in the seventh embodiment, the dynamic vibration reducer 263 is disposed in the space 261 of the upper connecting portion 102 b of the handgrip 102 , which is located relatively close to the axis of the cylinder 141 . Therefore, the vibration reducing function of the dynamic vibration reducer 263 can be effectively performed against vibration in the axial direction of the cylinder in working operation of the hammer drill 101 .
[0057] Generally, in the case of the hammer drill 101 in which the axis of the driving motor 111 is generally perpendicular to the axis of the cylinder 141 , the handgrip 102 is designed to be detachable from the rear end of the body 103 . Therefore, when, like this embodiment, the dynamic vibration reducer 263 is disposed in the space 261 of the connecting portion 102 b of the handgrip 102 , the dynamic vibration reducer 263 can be mounted in the handgrip 102 not only in the manufacturing process, but also as a retrofit at the request of a purchaser.
Eighth Embodiment
[0058] In the eighth representative embodiment, like the seventh embodiment, a dynamic vibration reducer 273 is disposed by utilizing a space existing inside the handgrip 102 . Specifically, as shown by dotted line in FIG. 2F , the dynamic vibration reducer 273 is disposed by utilizing a space 271 existing within the lower connecting portion 102 c of the handgrip 102 . Like the above-described space 261 of the upper connecting portion 102 b , the space 271 of the lower connecting portion 102 c extends in the longitudinal direction (in the axial direction of the cylinder 141 ). Therefore, as shown by dotted line in FIG. 2F , the dynamic vibration reducer 273 has a rectangular shape elongated in the longitudinal direction. The dynamic vibration reducer 273 is the same as the first embodiment in the construction, except for the shape, including a body, a weight and biasing springs, which are not shown.
[0059] According to the eighth embodiment, in which the dynamic vibration reducer 273 is disposed in the space 271 existing inside the handgrip 102 , like the above-described embodiments, the dynamic vibration reducer 273 can perform the vibration reducing action in working operation of the hammer drill 101 , while avoiding size increase of the body 103 . Further, the dynamic vibration reducer 273 can be protected from an outside impact in the event of drop of the hammer drill 101 . Further, if the handgrip 102 is designed to be detachable from the body 103 , like the seventh embodiment, the dynamic vibration reducer 273 can be mounted in the handgrip 102 not only in the manufacturing process, but also as a retrofit at the request of a purchaser.
[0060] In the above-described embodiments, an electric hammer drill has been described as a representative example of the power tool. However, other than the hammer drill, this invention can not only be applied, for example, to an electric hammer in which the hammer bit 119 performs only a hammering movement, but to any power tool, such as a reciprocating saw and a jigsaw, in which a working operation is performed on a workpiece by reciprocating movement of the tool bit.
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A power tool capable of performing vibration damping action in working operation, without an increase in size. The working tool includes a motor, a housing in which an internal mechanism driven by the motor is stored, a tool bit disposed on one end of the housing, a hand grip continuously connected to the other end of the housing, and a dynamic damper. The dynamic damper is disposed by utilizing a space between the housing and the internal mechanism so that the damping direction of the dynamic damper faces the longitudinal direction of the tool bit.
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FIELD OF INVENTION
[0001] The present invention relates to water taps and faucets having a locking mechanism. The present invention has particular but not exclusive application to domestic water taps and faucets. Reference will now be made to domestic water taps and faucets but this is by way of example only and the invention is not limited to this example.
BACKGROUND OF THE INVENTION
[0002] Domestic water taps can pose a serious safety risk to children and the elderly. Children can receive serious scalds as a result of playing with hot water taps in baths, sinks or showers. Furthermore, children playing with water taps can cause water wastage or flooding. As well in baths, there is an increased risk of drowning where there is an opportunity for children to turn on a tap. Similarly, the elderly and infirm may accidentally scald themselves or cause flooding in situations where they are unfamiliar with the tap operation or have difficulty operating a tap.
OBJECT OF THE INVENTION
[0003] It is an object of the present invention to provide a tap assembly which overcomes at least in part one or more of the above mentioned disadvantages.
SUMMARY OF THE INVENTION
[0004] The present invention broadly resides in a tap handle assembly for positioning about an installed tap body that includes an outwardly extending spindle; including a handle body means that has a body aperture and engagement means for engaging an outer end of the spindle;
[0005] a pin positionable and moveable within the body aperture;
[0006] a biasing means to bias the position of the pin within the body aperture;
[0007] wherein when assembled the pin is biased to the tap body to substantially prevent the movement of the spindle and to restrict the flow from the tap.
[0008] The tap handle assembly is preferably used with a quarter turn lever-type faucet; a rotary tap; or a mixer tap, such as a flick mixer tap.
[0009] The handle body means includes a tap handle portion integral with or operatively associated therewith a tap housing portion. In one embodiment the tap handle portion and tap housing portion are separate and the tap handle portion is engageable with the outer end of the spindle while the tap housing portion has the body aperture. This embodiment is preferably used with rotary type taps.
[0010] In an alternate embodiment, the tap handle portion and tap housing portion are integral and the tap housing portion is engageable with the outer end of the spindle and has the body aperture. This embodiment is preferably used with quarter turn lever-type faucets and mixer type taps.
[0011] The engagement means of the handle body means is preferably by a screw threaded fastener such as a grub screw and or by friction fitting with male-female complementary shaped parts.
[0012] The engagement means of the handle body means may be located in the tap handle portion or in the tap housing portion.
[0013] The body aperture may be located in the tap handle portion or in the tap housing portion.
[0014] The body aperture preferably has a diameter that narrows between an outside surface to an inside surface of the handle body means. More preferably the body aperture has an internal peripheral ridge thereby reducing the diameter of the aperture proximal to the inside surface of the handle body means. The pin preferably has an enlarged end to provide grip for an operator and an outwardly extending flange to prevent the pin from passing through the body aperture. The pin has a stem portion. The stem portion preferably has an outwardly extending flange part way along the stem portion to abut the internal peripheral ridge within the body aperture of the handle body means.
[0015] The biasing means is preferably a spring. More preferably the biasing means is a helical spring. Preferably the helical spring is positioned around the stem portion of the pin between the knob and the outwardly extending flange. Preferably the stem portion and the spring are held by a retaining nut with the knob positioned on the outside of the handle body means. Preferably the retaining nut is threaded and is fastened to the handle body means by a complementary screw thread on an internal peripheral surface of the aperture. The spring is preferably retained on the pin by the outwardly extending flange, and the outwardly extending flange is preferably retained within the body aperture by abutting the internal peripheral ridge within the body aperture.
[0016] The free end of the stem portion of the pin may engage by any suitable means to substantially restrict the movement of the tap body.
[0017] In one embodiment, the free end of the stem portion can abut a surface of the tap body. In an alternate embodiment, the free end portion of the pin can engage a hole or slot in the tap body. The hole or slot is preferably located in the spindle, a collar or sleeve operatively associated with the spindle or housing operatively associated with and surrounding the spindle.
[0018] Preferably the pin is disengaged by pulling on the knob portion, thus compressing the spring between the retaining nut and the outwardly extending flange. Preferably after the pin is disengaged, the pin will not restrict movement and will allow free movement of the tap handle portion and spindle until the tap handle is returned to the closed position when the end portion will re-engage to substantially restrict further movement.
[0019] In one embodiment the biasing force necessary to disengage the pin is of sufficient magnitude to prevent a tap being turned on by a child, elderly or infirm.
[0020] The present invention in another aspect provides a tap handle assembly for positioning about an installed flick mixer tap body that includes an outwardly extending spindle; including
[0021] a handle body means that has a body aperture and engagement means for engaging an outer end of the spindle, said handle body means has an integral tap handle portion and tap housing portion, said tap housing portion has the body aperture and a complementary shaped part for engaging an outer end of the spindle;
[0022] a pin positionable and moveable within the body aperture;
[0023] a biasing means to bias the position of the pin within the body aperture;
[0024] wherein when assembled the pin is biased to a cap portion of the tap body to substantially prevent the movement of the spindle in an outward direction and thus restrict the flow from the tap.
[0025] Preferably the pin abuts the cap portion when engaged and prevents the movement of the spindle in an outward direction to restrict the flow of water from the tap. Preferably the pin engages with the cap portion by contacting a lip edge of the cap portion of the tap body to prevent the tap being opened by moving a flick handle in an outward direction. The cap portion may have a locating recess or aperture for positioning of the pin.
[0026] In another aspect the present invention resides in a tap handle assembly for positioning about an installed quarter turn tap body that includes an outwardly extending spindle; including
[0027] a handle body means that has a body aperture and engagement means for engaging an outer end of the spindle, said handle body means has an integral tap handle portion and tap housing portion, said tap housing portion has the body aperture and a complementary shaped part for engaging an outer end of the spindle;
[0028] a pin positionable and moveable within the body aperture;
[0029] a biasing means to bias the position of the pin within the body aperture;
[0030] wherein when assembled the pin is biased to the spindle to substantially prevent the movement of the spindle and to restrict the flow from the tap.
[0031] In a further aspect the present invention resides in a tap handle assembly for positioning about an installed tap body for a rotary type tap that includes an outwardly extending spindle; including
[0032] a handle body means that has a body aperture and engagement means for engaging an outer end of the spindle, said handle body means has a separate tap handle portion and separate tap housing portion, said tap housing portion has the body aperture and the tap handle portion has a complementary shaped part for engaging an outer end of the spindle;
[0033] a pin positionable and moveable within the body aperture;
[0034] a biasing means to bias the position of the pin within the body aperture;
[0035] wherein when assembled the pin is biased to the spindle to substantially prevent the movement of the spindle and to restrict the flow from the tap.
[0036] In this aspect the pin preferably engages with a hole in the spindle or a collar attached to the spindle. The collar surrounding the spindle is preferably fixable and repositionable along the length of the spindle shaft to allow for variation in the distance from a wall during the installation of the tap assembly. Preferably when the collar has been fixed in position, the pin can engage with the aperture to prevent movement of the spindle shaft and tap handle.
[0037] The taps with the locking pin can be used to control the flow of water, gas or some other suitable medium.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] In order that the present invention can be more readily understood reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention and wherein:
[0039] FIG. 1 is an exploded view of a biased pin lock;
[0040] FIG. 2 is a plan view of a flick mixer tap incorporating a biased pin lock;
[0041] FIG. 3 is a diagrammatic cross sectional view of the flick mixer tap of FIG. 2 ;
[0042] FIG. 4 is a diagrammatic cross sectional view of an alternate embodiment of a rotary tap incorporating a biased pin lock;
[0043] FIG. 5 is a plan view of the rotary tap of FIG. 4 ;
[0044] FIG. 6 is an exploded view of the rotary tap of FIG. 4 ;
[0045] FIG. 7 is a plan view of an alternate embodiment of a quarter turn lever tap incorporating a biased pin lock;
[0046] FIG. 8 is a diagrammatic cross sectional view of the quarter turn lever tap of FIG. 7 ;
[0047] FIG. 9 is an exploded view of the tap body of the quarter turn lever tap of FIG. 7 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0048] With reference to FIG. 1 there is shown a biased locking pin 10 for a tap handle assembly for a flick mixer tap. The locking pin 10 has a knob 11 , a stem portion 15 , an outwardly extending flange 16 and an end portion 17 . The knob 11 has a threaded recess 14 and is connected to the stem portion 15 by screw attachment to a threaded end 13 . A helical spring 18 is mounted on the stem portion 15 between the outwardly extending flange 16 and the knob 11 . A threaded retaining ring 12 is mounted on the stem portion 15 between the helical spring 18 and the knob 11 . The stem portion 15 , outwardly extending flange 17 and helical spring 18 are retained in a wide aperture section 21 in a tap handle body 19 by the threaded retaining ring 12 to a threaded periphery 24 of a body aperture 20 . The wide aperture section 21 is adjacent a narrow aperture section 22 . The pin end 17 protrudes through the aperture 20 where it engages to prevent movement of the tap handle body 19 and a spindle portion (not shown) and stop the flow of water. The pin end 17 of the locking pin 10 is disengaged by pulling on the knob portion 11 , thus compressing the spring 18 between the retaining nut 12 and the outwardly extending flange 16 to allow free movement of the tap handle body 19 and spindle portion (not shown).
[0049] With reference to FIGS. 2 and 3 there is shown a flick mixer tap handle assembly 30 . The flick mixer tap assembly 30 has a tap handle body 31 in connection with an outwardly extending spindle portion 40 of a tap body 32 . The tap handle body 31 has a flick handle portion 38 and a tap housing portion 39 . The spindle 40 is attached to a recess 41 in the tap housing portion 39 . Upward movement of the flick handle 38 moves the spindle portion 40 upwards to open the tap and allow water to flow. The tap body 32 has a cap portion 37 with a lip 36 . The tap handle body 31 has a body aperture 34 housing a locking pin 33 . The locking pin 33 has an end portion 35 . When the tap is in the closed position, the end portion 35 of the locking pin 33 abuts the lip 36 of the cap portion 37 to prevent the tap being opened by the upward movement of the flick handle 38 . The end portion 35 of the locking pin 33 is disengaged from the lip 36 by pulling on the locking pin 33 , allowing free movement of the spindle 39 and the tap handle body 31 . When disengaged, the end portion 35 of the locking pin 33 is free to move against the cap portion 37 and does not further restrict the movement of the tap handle and spindle until the tap handle body 31 is returned to the closed position when the end portion 35 will re-engage with the lip 36 .
[0050] With reference to FIGS. 4 , 5 and 6 there is shown a rotary tap handle assembly 50 . The rotary tap assembly 50 has a handle body 51 comprising a tap handle portion 53 and a tap housing portion 52 . The tap housing portion 52 accommodates a tap body 63 having a spindle 64 . The spindle 64 has an outer spindle end 55 which is connected to a recess 54 in the tap handle portion 53 . The spindle 64 passes through a collar 59 within the tap housing portion 52 . The collar 59 is moveable along the spindle 64 to allow for variations occurring during installation of the tap. The collar 59 is positioned, aligned and secured to the spindle 64 by a grub screw 62 through an aperture 61 in the collar 59 . The tap housing portion 52 has an aperture 58 for a locking pin 56 . The locking pin 56 has an end portion 59 . When the tap handle 53 is in the closed position, the end portion 59 of the locking pin 56 engages with a second aperture 60 in the collar 59 to lock the spindle 64 and prevent rotation of the tap handle 53 . The end portion 59 of the locking pin 56 is disengaged from the aperture 60 by pulling on the locking pin 56 , allowing free movement of the spindle 64 and the tap handle 53 . Once disengaged, the end portion 57 of the locking pin 57 is free to move against the circumference of the collar 59 and does not further restrict the movement of the tap handle 53 and spindle 64 until the tap handle 53 is returned to the closed position when the end portion 57 will re-engage with the aperture 60 in the collar 59 .
[0051] With reference to FIGS. 7 , 8 and 9 there is shown a quarter turn lever tap handle assembly 70 . The quarter turn lever tap assembly 70 has a handle body 71 comprising a tap handle portion 73 and a tap housing portion 72 . The tap housing portion 72 accommodates a tap body 77 having a spindle portion 81 . The spindle portion 81 has a spindle end 78 which is secured to the tap housing portion 72 by a screw 79 . The tap housing portion 72 has an aperture 75 housing a locking pin 74 . The locking pin 74 has an end portion 76 . When the tap handle 73 is in the closed position, the end portion 76 of the locking pin 74 engages with an aperture 80 in the spindle portion 81 to prevent rotation of the tap handle 73 . The end portion 76 of the locking pin 74 is disengaged from the aperture 80 by pulling on the locking pin 74 , allowing free movement of the spindle portion 81 and the tap handle 73 . Once disengaged, the end portion 76 of the locking pin 74 is free to move against the external surface of the spindle portion 81 and does not further restrict the movement of the tap handle 73 and spindle portion 81 until the tap handle 73 is returned to the closed position when the end portion 76 of the locking pin 74 will re-engage with the aperture 80 in the spindle portion 81 .
Advantages
[0052] An advantage of the preferred embodiment of the tap assembly is the provision of a tap that cannot be turned on accidently.
[0053] The biasing force required to disengage the locking pin is of sufficient magnitude such that the tap cannot be turned on by a child. The tap assembly can therefore protect against accidental scalding from water from a hot tap. The tap assembly can also protect against flooding and drowning situations, as well as preventing against water wastage.
[0054] The biasing force necessary to disengage the locking pin is also of sufficient magnitude to prevent a tap being turned on by the elderly or infirm. Taps having the biased pin lock are therefore useful in aged care establishments.
Variations
[0055] It will of course be realized that while the foregoing has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as is herein set forth.
[0056] Throughout the description and claims this specification the word “comprise” and variations of that word such as “comprises” and “comprising”, are not intended to exclude other additives, components, integers or steps.
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The present invention is directed to a tap handle assembly for positioning about an installed tap body that includes an outwardly extending spindle. The tap handle assembly has a handle body means that has a body aperture and engagement means for engaging an outer end of the spindle, a pin positionable and moveable within the body aperture, and a biasing means to bias the position of the pin within the body aperture. When the tap handle assembly is assembled with the tap body, the pin is biased to the tap body to substantially prevent the movement of the spindle and to restrict the flow from the tap.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an impeller for a radial-flow heat dissipating fan. In particular, the present invention relates to an impeller for a radial-flow heat dissipating fan with increased air inlet amount.
[0003] 2. Description of Related Art
[0004] FIG. 1 of the drawings illustrates a conventional radial-flow heat dissipating fan. The radial-flow heat dissipating fan in FIG. 1 comprises a casing 1 and a cover 2 . The casing 1 includes a compartment 11 and a side outlet 12 . The cover 2 is mounted to the casing 1 and includes an inlet 21 . An impeller 3 is rotatably mounted in the compartment 11 of the casing 1 and includes a hub 31 , a supporting member 32 extending from the hub 31 , and a plurality of blades 33 each having an edge mounted on a side of the supporting member 32 .
[0005] FIG. 2 illustrates another conventional radial-flow heat dissipating fan, wherein a connecting ring 34 extends across the other edges of the blades 33 to improve the strength. In operation, turning of the blades 33 of the impeller 3 drives axial airflow into the casing 1 via the inlet 21 of the cover 2 . Then, the axial airflow is driven by the blades 33 to exit the casing 1 via the side outlet 12 for dissipating an object such as a fin.
[0006] Although the above radial-flow heat dissipating fans are widely used in computers, there are still several problems. First, the other edge 33 a of each blade 33 is located at the same level as a top face of the hub 31 . After assembly, the top face of the hub 31 is very close to the inlet 21 of the cover 2 . Thus, the incoming air can only pass through the inlet 21 via the gap between the blades 33 , resulting in limitation to the amount of the incoming axial airflow. In this case, if the other edge 33 a of each blade 33 has a relatively long radial length, the other edge 33 a interferes with entrance of the incoming axial airflow via the inlet 21 . The air inlet amount could not be increased, the air outlet amount and the wind pressure are reduced. Secondly, if the other edge 33 a of each blade 33 has a relatively long radial length, the incoming axial airflow entering the casing 1 via the inlet 21 is directly guided by the rotation of the edge 33 a and thus turns into centrifugal airflow, leading to blowing noise and adversely affect to the rotational efficiency of the impeller.
OBJECTS OF THE INVENTION
[0007] An object of the present invention is to provide an impeller for a radial-flow heat dissipating fan for increasing air inlet amount and air outlet amount.
[0008] Another object of the present invention is to provide an impeller for a radial-flow heat dissipating fan for increasing outlet wind pressure.
[0009] A further object of the present invention is to provide an impeller for a radial-flow heat dissipating fan for lowering blowing noise.
SUMMARY OF THE INVENTION
[0010] In accordance with an aspect of the present invention, an impeller for a radial-flow heat dissipating fan comprises a hub, a plurality of blades surrounding the hub, and means for connecting the blades to a circumference of the hub, allowing joint rotation of the hub and the blades.
[0011] More than one blade include an air inlet side edge and an air outlet side edge. The air inlet side edge of each of the more than one blade has a radial length smaller than that of the air out side edge, thereby increasing an air inlet amount and smoothly changing incoming axial airflow into centrifugal airflow.
[0012] In an embodiment, the inner edge of each blade includes a first section and a second section having a slope or curvature different from that of the first section. In another embodiment, the inner edge of each blade includes a shoulder.
[0013] In an embodiment, each blade includes an axial length greater than that of the hub, defining a buffering space between a top of the hub and the inner edges of the blade for increasing an air inlet area and for assisting in change of the axial incoming airflow into the centrifugal airflow.
[0014] In another embodiment, the impeller includes a first set of blades and a second set of blades that are alternately disposed. Each of the first set of blades has a rectilinear inner edge such that the air inlet side edge of each of the first set of blades has a radial length the same as that of the air outlet side edge of each of the first set of blades. The air inlet side edge of each of the second set of blades has a radial length smaller than that of the air outlet side edge of each of the second set of blades.
[0015] In an embodiment, a connecting ring extends across the air inlet side edge of each blade and another connecting ring extends across the air outlet side edge of each blade. At least one of the blades is connected by a supporting member to the circumference of the hub.
[0016] In a further embodiment, an annular plate extends from the circumference of the hub, and the blades are mounted on a side of the annular plate.
[0017] Other objects, advantages and novel features of this invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is an exploded perspective view of a conventional radial-flow heat dissipating fan;
[0019] FIG. 2 is an exploded perspective view of another conventional radial-flow heat dissipating fan;
[0020] FIG. 3 is a perspective view, partly cutaway, of a first embodiment of an impeller for a radial-flow heat dissipating fan in accordance with the present invention;
[0021] FIG. 4 is a side view of the impeller in FIG. 3 ;
[0022] FIG. 5 is a view similar to FIG. 4 , illustrating operation of the impeller;
[0023] FIG. 6 is a side view illustrating a second embodiment of the impeller in accordance with the present invention;
[0024] FIG. 7 is a perspective view, partly cutaway, of a third embodiment of the impeller in accordance with the present invention;
[0025] FIG. 8 is a side view of the impeller in FIG. 7 ;
[0026] FIG. 9 is a perspective view of a fourth embodiment of the impeller in accordance with the present invention; and
[0027] FIG. 10 is side view of the impeller in FIG. 9 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] Referring to FIGS. 3 and 4 , a first embodiment of an impeller 4 in accordance with the present invention comprises a hub 41 , at least one supporting member 42 , a plurality of blades 43 , and at least one connecting ring 44 , 45 . The impeller 4 may be coupled with a motor (not shown) and assembled with a casing 1 and a cover 2 (see FIGS. 1 and 2 ) to form a complete radial-flow heat dissipating fan. The motor is mounted inside the hub 41 that is rotatably mounted in a compartment 11 in the casing 11 . In this embodiment, a plurality of supporting members 42 are provided, with each supporting member 42 being connected between a circumference of the hub 41 and an associated one of the blades 43 . Preferably, each supporting member 42 is a wave-like rib extending from the circumference of the hub 41 to the associated blade 43 . A first connecting ring 44 extends across an air inlet side edge 43 a of each blade 43 , and a second connecting ring 45 extends across an air outlet side edge 43 b of each blade 43 , providing a structure with improved strength.
[0029] Still referring to FIGS. 3 and 4 , each blade 43 further includes an inner edge facing the hub 41 and an outer edge 43 d facing away from the hub 41 . The inner edge of each blade 43 includes at least one section. In this embodiment, the inner edge of each blade 43 includes a first section 43 c 1 adjacent to the air inlet side and a second section 43 c 2 adjacent to the air outlet side. The inner edges of some of the blades 43 are connected to the supporting members 42 . The first section 43 c 1 and the second section 43 c 2 have different slopes or different curvatures such that a radial length of the air inlet side edge 43 a of each blade 43 is smaller than that of the air outlet side edge 43 b of each blade 43 , thereby avoiding interference to drawing of the air into the casing 1 via the inlet 21 . Further, the outer edge 43 a of each blade 43 is parallel to a rotational axis 40 of the impeller 43 without any change in the radial length. Further, an axial level of the impeller 43 is preferably above the hub 41 such that a buffering space 400 is defined between a top face of the hub 41 and the first sections 43 c 1 of the inner edges of the blades 43 . The air inlet area is increased, and airflow can be smoothly changed from the axial direction to the centrifugal direction.
[0030] Referring to FIG. 5 , when the blades 43 of the impeller 4 turns, axial airflow is drawn into the buffering space 400 via the inlet 21 of the cover 2 . Since the first section 43 c 1 of the inner edge of each blade 43 is slanted or curved, the air inlet side edge 43 a of each blade 43 has a relatively smaller radial length. Thus, the buffering space 400 can be enlarged to the maximum. When the axial airflow enters the buffering space 400 , the buffering space 400 provides a sufficient space for changing the axial airflow into centrifugal airflow. Thus, pressurized centrifugal airflow is obtained and exits the casing 1 via the outlet 12 . The slopes or curvatures of the first and second sections 43 c 1 and 43 c 2 of the inner edges of the blades 43 provide the lower portions of the blades 43 with a greater air driving power such that air flows easily in the lower portions of the blades 43 . Namely, the directional change from the axial direction to the centrifugal direction is not completely carried out at the upper portions of the blades 43 , which lowers the blowing noise of the blades 43 .
[0031] FIG. 6 illustrates a second embodiment of the invention, wherein the first section 43 c 3 and the second section 43 c 4 of the inner edge of each blade 43 are rectilinear to form a shoulder. This embodiment provides advantages the same as those of the first embodiment.
[0032] FIGS. 7 and 8 illustrate a third embodiment of the invention, wherein the impeller 4 comprises two sets of alternately disposed blades 43 and 43 ′ having different shapes. Each of a first set of blades 43 has a structure the same as that in the first embodiment. Each of a second set of blades 43 ′ has a rectilinear inner edge 43 c ′ throughout an axial length of the blade 43 ′. In other words, the inlet side edge of each of the second set of blades 43 ′ has a radial length the same as that of the outlet side edge of each of the second set of blades 43 ′. Drawing of air into the casing 1 via the inlet 21 of the cover 2 is not interfered. Further, a buffering space 400 is defined between the inner edges 43 c 1 of the blades 43 , the inner edges 43 c ′ of the blades 43 ′, and a top face of the hub 41 . Similar to the first embodiment, the air inlet area is increased, the airflow can be smoothly changed from the axial direction to the centrifugal direction, and the blowing noise is lowered.
[0033] FIGS. 9 and 10 illustrate a fourth embodiment of the invention, in this embodiment, the impeller 5 includes a hub 51 , a plate-like supporting member 52 extending radially outward from a circumference of the hub 51 , and a plurality of blades 53 provided on a side of the supporting member 52 . Each blade 53 includes an inner edge 53 c , a rectilinear outer edge 53 d , an air inlet side edge 53 a , and an air outlet side edge 53 b . The inner edge 53 c is slanted. Alternatively, the inner edge 53 c may include two sections similar to the first embodiment. The air outlet side edge 53 b has a radial length longer than that of the air inlet side edge 53 a . Thus, drawing of air into the casing 1 via the inlet 21 of the cover 2 is not interfered. The axial height of each blade 43 is greater than that of the hub 51 . Thus, a buffering space 500 is defined between the inner edges 53 c of the blades 53 and a top face of the hub 51 . Similar to the first embodiment, the air inlet area is increased, the airflow can be smoothly changed from the axial direction to the centrifugal direction, and the blowing noise is lowered.
[0034] While the principles of this invention have been disclosed in connection with specific embodiments, it should be understood by those skilled in the art that these descriptions are not intended to limit the scope of the invention, and that any modification and variation without departing the spirit of the invention is intended to be covered by the scope of this invention defined only by the appended claims.
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An impeller for a radial-flow heat dissipating fan includes a hub and a plurality of blades surrounding the hub. The blades are connected to a circumference of the hub to allow joint rotation of the hub and the blades. More than one blade include an air inlet side edge and an air outlet side edge. The air inlet side edge of each of the more than one blade has a radial length smaller than that of the air out side edge, thereby increasing an air inlet amount and smoothly changing incoming axial airflow into centrifugal airflow.
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RELATED APPLICATION
[0001] This application is a continuation of U.S. patent application Ser. No. 10/712,273, now U.S. Pat. No. ______, filed Nov. 14, 2003, which claims the benefit of U.S. Provisional Application No. 60/426,393, filed Nov. 15, 2002, which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a method, system and medium for modeling and controlling processes. More specifically, the present invention relates to modeling and controlling semiconductor-processing equipment that has multivariate input parameters.
BACKGROUND OF THE INVENTION
[0003] In manufacturing products that include precision discrete parts (e.g., microelectronic chips on silicon substrates), controlling manufacturing processes plays a crucial role. Controlling such processes may require, among other things, monitoring the characteristics of manufactured parts (e.g., processed wafers, hereinafter referred to as outputs) and adjusting input parameters accordingly. By adjusting the values of the input parameters, different types of outputs can be produced and the characteristics of the outputs can also be controlled.
[0004] For automating the control of the manufacturing processes, a mathematical model of the processing equipment can be used. One example of such a model is called a predictive model. This model is used to predict the future output values (e.g., the characteristics of products) based on historical information (e.g., input parameter values and the corresponding output qualities).
[0005] One such predictive model is an offset technique, which is illustrated in FIG. 1 . In particular, the values of a number of input parameters 101 are received by an input/output dependency model 103 , which calculates a predicted output value y 1 Pred 105 based on the input values. A corrector 109 then compares the predicted value y 1 Pred with an actual output value y 1 a 107 for the given values of the input parameters. If the predicted and actual output values are similar to each other within a certain range, no change is made to the input/output dependency model 103 . If the predicted and actual output values are different (e.g., outside the range) from each other, the predictor input/output dependency model 103 is modified by adjusting an offset value (O 1 ) 111 based on the magnitude of the difference.
[0006] In equipment that has more than one output, at least some of the outputs may include mutual (shared) inputs. This means the output values of the equipment are not completely independent from each other (e.g., changing an input to adjust a given output may unintentionally change the characteristics of other outputs). In a conventional modeling technique, each output has its own correction system as if the output values are independent from each other. Because the dependencies between the different outputs are not accounted for by the conventional technique, it does not always lead to accurate predictions. In addition, adjusting one offset of one output can affect other outputs.
SUMMARY OF THE INVENTION
[0007] Embodiments of the present invention advantageously overcome the above-described shortcomings of the aforementioned techniques. More specifically, embodiments of the present invention provide a system, method and medium for controlling semiconductor-processing equipment that has multivariate input parameters and outputs.
[0008] Embodiments of the present invention minimize the effects of outputs being interdependent from each other. This is achieved by providing input parameter transformations having transformation coefficients. The coefficients are obtained by minimizing a score function. This, in turn, allows accurate models to be obtained. Using the models, highly precise control of manufacturing equipment is accomplished.
[0009] In particular, an example method according to embodiments of the present invention includes the steps of identifying at least one input that causes a change in at least two of a plurality of outputs, storing values of the identified inputs and corresponding empirical output values, and calculating and storing predicted output values, based on, in part, the values of the identified inputs. The example method may further include the steps of calculating a set of transform coefficients by minimizing a score equation that is a function of, in part, differences between one or more of the empirical output values and their corresponding predicted output values, and calculating one or more input values for one or more desired output values based on, in part, the calculated set of transform coefficients.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The detailed description of the present application showing various distinctive features may be best understood when the detailed description is read in reference to the appended drawings in which:
[0011] FIG. 1 is a diagram showing a conventional offset model;
[0012] FIG. 2 is a diagram illustrating processing equipment;
[0013] FIG. 3 is a diagram illustrating a model of the processing equipment shown in FIG. 2 in accordance with embodiments of the present invention;
[0014] FIG. 4 is a block diagram illustrating various components of embodiments of the present invention;
[0015] FIG. 5 is a flow chart illustrating processing steps of embodiments of the present invention;
[0016] FIG. 6 is a diagram illustrating a CMP process;
[0017] FIG. 7 is a block diagram representation of an example embodiment of a computer configured to perform embodiments of the present invention; and
[0018] FIG. 8 is a diagram illustrating an example of a memory medium that can be used for storing computer programs of embodiments of the present invention.
DETAILED DESCRIPTION
[0019] Embodiments of the present invention generally provide systems, methods and mediums for creating one or more adaptive process models to mathematically represent multivariate input parameter systems. The present invention is particularly applicable in a manufacturing process such as manufacturing and/or processing semiconductor wafers. In particular, the present invention relates to modeling techniques as used by equipment involved in the manufacturing of semiconductor wafers. A general overview of embodiments of the present invention is provided below. It will be followed by a specific example implementation of the present invention.
[0020] Before discussing embodiments of the present invention, FIG. 2 shows a simplified graphical representation of processing equipment 205 with input parameters 201 and outputs 203 . Examples of processing equipment include etcher tools, deposition tools, chemical mechanical planarization (CMP) tools, etc. The processing equipment 205 can include one or more tools. Depending upon the values of the input parameters 201 , different processes can be achieved. For instance, in a deposition tool, different types of layers can be deposited on a wafer and/or the thickness of the layer can be varied.
[0021] As a general overview of embodiments of the present invention, in FIG. 3 , the processing equipment 205 has a set of input parameters 301 , a set of predicted outputs 303 , and a prediction model 305 therebetween (replacing the processing equipment of FIG. 2 ). The overall goal of the prediction model is to minimize differences between the predicted output values and empirically collected output values (i.e., the actual output values). Once the prediction model is optimized (e.g., the differences between the predicted and actual output values have been minimized), the model can then be used in setting input parameters based on desired output values. In other words, for a given set of desired output values, the model can be used in a reverse fashion to calculate the input parameter values that would cause output values close to the desired output values. The calculated input parameter values are also known as recipes.
[0022] In embodiments of the present invention, the step of obtaining the predictive model can be divided into two steps. The first is to transform the values of the input parameters 301 into transformed input values 307 . The second is to use the transformed input values 307 in calculating predicted output values 303 .
[0023] With respect to the transformation, input parameter values (X 1 , X 2 , X 3 ) along with coefficient vector {right arrow over (P)} are transformed into (X′ 1 , X′ 2 , and X′ 3 ) by transform functions ψ 1 , ψ 2 , and ψ 3 . Examples of transformation functions include:
[0024] X′ 1 =PX 1 ; X′ 2 =PX 2 (In this example, the value of {right arrow over (P)} is identical for both X 1 and X 2 .)
[0025] 2) X′ 1 =P 11 X 1 +P 12 X 1 2 ; X′ 2 =P 21 X 1 2 +P 22 X 2 2 +P cross X 1 X 2 (In this example, P 11 , P 12 , P 21 , P 22 and P cross can have different values.)
[0026] The coefficient values are calculated by the steps of: a. collecting historical information on input parameter values and actual output values; b. creating a score function based on the collected information; and c. finding the coefficient values that minimize the score function, S p .
[0027] The above steps are described by making references to semiconductor processing tools. As such, the step of collecting the historical information entails a set of data points for processing a number of wafers. In particular, input parameter values and actual output values for a number of wafers that have been processed by the processing equipment would be collected. This collection would then be used in the next step of minimizing the score function. Here, the score function, S p , is:
S p = ∑ i , k W i , k ( y actual ik - y predicted ik ( X -> i ′ ( X -> i , P -> ) ) ) 2
where:
i—number of wafer; k—number of output; y actual —an actual output value; y predicted —a predicted output value, as calculated based on transformed inputs for a particular wafer i ({right arrow over (X)}′ i ); {right arrow over (X)}′ i =(X′ 1 i , X′ 2 i , X′ 3 i ) is the transformed input vector, calculated on the base of the actual input; and {right arrow over (X)} i =(X 1 i , X 2 i , X 3 i ) for wafer i together with the transformation parameters {right arrow over (P)}. This calculation is performed using the following transformation functions:
ψ 1 (X 1 ,X 2 , X 3 ,{right arrow over (P)}); ψ 2 (X 1 , X 2 , X 3 ,{right arrow over (P)});and ψ 3 (X 1 ,X 2 ,X 3 ,{right arrow over (P)}).
The next step, as noted above, is to minimize the score S p , i.e., to find {right arrow over (P)} values that provide the minimum of S p (S p min)
[0034] The above-described steps calculate an optimal {right arrow over (P)} (i.e., a vector of coefficients for input transformation functions) such that the prediction model of the present invention provides the closest possible predicted outputs to the actual outputs. In a processing model with multivariate input parameters, when the score is minimized, the negative effect of the interdependencies between output values on the model accuracy would also be minimized.
[0035] Now turning to describe an example implementation of the embodiments described above, as shown in FIG. 4 , the example implementation includes a number of components: an input transformer 401 , an input-output dependency model 403 , a corrector 405 and a storage device 407 . All these components can be implemented in hardware, firmware, software and/or any combination thereof.
[0036] These components are further explained by also referring to FIG. 5 . In particular, the historical information (i.e., y a ik ,{right arrow over (X)} i ) is stored into the storage device 407 . The corrector 405 then retrieves the historical information (y a ik ,{right arrow over (X)} i ) from the storage device 407 (step 501 ). Since the retrieved historical information contains raw input parameter values, the information is sent to the input transformer 401 along with coefficients {right arrow over (P)} (step 503 ). The coefficient {right arrow over (P)} can be stored in the storage device 407 or in the corrector 405 .
[0037] The input transformer 401 , upon receiving the information from the corrector 405 , calculates transformed input parameter values {right arrow over (X)}′ i (step 505 ). Once the transformed input parameter values are calculated, the input transformer 401 sends the transformed input values to the corrector 405 .
[0038] The corrector 405 , upon receiving the transformed input parameter values from the input transformer 401 , sends the transformed input parameter values to the input/output dependence model 403 . The input/output dependency model 403 then calculates predicted output parameter values y pred (step 507 ). The corrector 405 then calculates the score S p , and sets a new {right arrow over (P)} (a vector of parameters of input transformation functions) in order to minimize the score S p (step 509 ). These steps can be repeated until an optimum {right arrow over (P)} that yields a minimal score S p is obtained, and return the optimum {right arrow over (P)}. Each time new data is obtained, a new score from new data is created and a new optimum {right arrow over (P)} value is calculated. This newly calculated vector {right arrow over (P)} could be used for transforming the input values, meaning: {right arrow over (P)} new ≡{right arrow over (P)} optimum .
[0039] In embodiments of the present invention, the optimum coefficients can be combined with the most recent vector such that:
{right arrow over (P)} new ≡{right arrow over (P)} previous +K ( {right arrow over (P)} optimum −{right arrow over (P)} previous ) wherein K <1.
[0040] As a new set of data points arrives, a new optimum {right arrow over (P)} can be recalculated.
[0041] Once a set of coefficients is calculated, a set of input values can be obtained (e.g., a recipe) for a desired set of output values. More specifically, from a set of desired values, a set of transformed input values, {right arrow over (X)}′ i , can be obtained by reversing the predictive model (e.g., the input/output dependence model 403 ). The transformed input values can then be reverse transformed using the coefficients {right arrow over (P)} to obtain the input value to produce the desired output values.
[0042] In the above-described embodiments, the raw input values are transformed using the calculated coefficients. The transformation is required to account for the dependencies among input parameters as graphically illustrated in FIG. 6 . More specifically, a surface of a wafer having five regions with varying degrees of roughness is to be polished by a CMP process. The goal is to achieve a flat surface depicted by a dotted line in FIG. 6 . In conventional techniques, one region would be polished without regard to the other regions. However, polishing one region can affect the polishing of another region (e.g., when an offset is applied in region 1 in order to bring the height in region 1 down to the broken line, the height in region 2 is also influenced by the changes of region 1 ). Using the embodiments of the present invention, these dependencies are accounted for.
[0043] An example embodiment of the computer in which embodiments of the present invention operate (e.g., the various components described in FIG. 4 ) is described below in connection with FIGS. 7-8 . FIG. 7 illustrates a block diagram of one example of the internal hardware 713 of a computer configured to perform embodiments of the present invention. A bus 756 serves as the main information highway interconnecting various components therein. CPU 758 is the central processing unit of the internal hardware 713 , performing calculations and logic operations required to execute embodiments of the present invention as well as other programs. Read only memory (ROM) 760 and random access memory (RAM) 762 constitute the main memory. Disk controller 764 interfaces one or more disk drives to the system bus 756 . These disk drives are, for example, floppy disk drives 770 , or CD ROM or DVD (digital video disks) drives 766 , or internal or external hard drives 768 . These various disk drives and disk controllers are optional devices.
[0044] A display interface 772 interfaces display 748 and permits information from the bus 756 to be displayed on display 748 . Communications with external devices, such as the other components of the system described above, occur utilizing, for example, communication port 774 . Optical fibers and/or electrical cables and/or conductors and/or optical communication (e.g., infrared, and the like) and/or wireless communication (e.g., radio frequency (RF), and the like) can be used as the transport medium between the external devices and communication port 774 . Peripheral interface 754 interfaces the keyboard 750 and mouse 752 , permitting input data to be transmitted to bus 756 . In addition to these components, the internal hardware 713 also optionally includes an infrared transmitter and/or infrared receiver. Infrared transmitters are optionally utilized when the computer system is used in conjunction with one or more of the processing components/stations/modules that transmit/receive data via infrared signal transmission. Instead of utilizing an infrared transmitter or infrared receiver, the computer system may also optionally use a low power radio transmitter 780 and/or a low power radio receiver 782 . The low power radio transmitter transmits the signal for reception by components of the production process, and receives signals from the components via the low power radio receiver. The low power radio transmitter and/or receiver are standard devices in industry.
[0045] Although the computer in FIG. 7 is illustrated having a single processor, a single hard disk drive and a single local memory, the analyzer is optionally suitably equipped with any multitude or combination of processors or storage devices. For example, the computer may be replaced by, or combined with, any suitable processing system operative in accordance with the principles of embodiments of the present invention, including sophisticated calculators, and hand-held, laptop/notebook, mini, mainframe and super computers, as well as processing system network combinations of the same.
[0046] FIG. 8 is an illustration of an example computer readable memory medium 884 utilizable for storing computer readable code or instructions. As one example, medium 884 may be used with disk drives illustrated in FIG. 7 . Typically, memory media such as floppy disks, or a CD ROM, or a digital video disk will contain, for example, a multi-byte locale for a single byte language and the program information for controlling the modeler to enable the computer to perform the functions described herein. Alternatively, ROM 760 and/or RAM 762 illustrated in FIG. 7 can also be used to store the program information that is used to instruct the central processing unit 758 to perform the operations associated with various automated processes of the present invention. Other examples of suitable computer readable media for storing information include magnetic, electronic, or optical (including holographic) storage, some combination thereof, etc.
[0047] In general, it should be emphasized that the various components of embodiments of the present invention can be implemented in hardware, software or a combination thereof. In such embodiments, the various components and steps would be implemented in hardware and/or software to perform the functions of embodiments of the present invention. Any presently available or future developed computer software language and/or hardware components can be employed in such embodiments of the present invention. For example, at least some of the functionality mentioned above could be implemented using Visual Basic, C, C++, or any assembly language appropriate in view of the processor(s) being used. It could also be written in an interpretive environment such as Java and transported to multiple destinations to various users.
[0048] The many features and advantages of embodiments of the present invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. For instance, output values can be transformed similar to the transform performed on the input parameters, and operations can be performed on the transformed output values similar to those performed on the transformed input parameters.
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A method, system, and medium of modeling and/or for controlling a manufacturing process is disclosed. In particular, a method according to embodiments of the present invention includes calculating a set of predicted output values, and obtaining a prediction model based on a set of input parameters, the set of predicted output values, and empirical output values. Each input parameter causes a change in at least two outputs. The method also includes optimizing the prediction model by minimizing differences between the set of predicted output values and the empirical output values, and adjusting the set of input parameters to obtain a set of desired output values to control the manufacturing apparatus. Obtaining the prediction model includes transforming the set of input parameters into transformed input values using a transformation function of multiple coefficient values, and calculating the predicted output values using the transformed input values.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority under 35 USC 119 from Japanese Patent Application, No. 2003-14477, the disclosure of which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an exposure apparatus, and in particular to an exposure apparatus which is capable of improving illumination efficiency and performing uniform exposure.
2. Description of the Related Art
An exposure apparatus is known, which has an illumination optical system for illuminating a two-dimensional spatial light modulator (which hereinafter is referred to as a two-dimensional SLM) such as an LCD (liquid crystal display) or a DMD (digital micromirror device; trademark) with light from a light source, and which exposes an optical image controlled by the two-dimensional SLM onto a photosensitive material. The two-dimensional SLM must be uniformly illuminated in such an exposure apparatus. An optical integrator is used for the illumination optical system. The optical integrator is generally used for a projector as well as an exposure apparatus (e.g., see Japanese Patent Application Laid-Open (JP-A) No. 3-111806).
The optical integrator divides a luminous flux, passes the divided luminous fluxes through different paths and then re-couples the fluxes in order to eliminate a correlation between intensity and position (distribution of intensity) and to uniform the intensity. There provided two systems for the optical integrator in accordance with a system for dividing a luminous flux. (1) One is a fly-eye type for spatially dividing a luminous flux by using a lens array (fly-eye lens) in which lenses are two-dimensionally arranged. (2) The other is a rod type for angularly dividing a luminous flux by multiple reflection by using a glass rod or a hollow rod with its inner surface being a mirror.
In the fly-eye type, two fly-eye lenses are used. A first fly-eye lens converges light onto lens cells of a second fly-eye lens. A light source image is imaged on the lens cells of the second fly-eye lens. The second fly-eye lens images the images which are on lens cells of the first fly-eye lens onto a two-dimensional SLM. In the rod type, a light source image is imaged on an incident surface of a rod, and an image at the exit surface of the rod is imaged on a two-dimensional SLM.
When a lamp such as an ultrahigh pressure mercury-vapor lamp is used for a light source, the configuration of light-emitting portion of the lamp is totally different from the configuration of an illumination area of a two-dimensional SLM (i.e., the configuration of an area of the two-dimensional SLM to be illuminated). Nevertheless, the above-described integrator enables uniform illumination only on a required area on the two-dimensional SLM to be used.
In actuality, in the case that Etendue is large and the configuration of the light-emitting portion is different from the configuration of an area illuminated by the light reaching a two-dimensional SLM as in the case of a lamp, entire light emitted from the lamp cannot be effectively utilized, resulting in a decreased illumination efficiency.
A description will be given with a specific example. When a lamp and a fly-eye type integrator are used, an arc image of the lamp is imaged by a first fly-eye lens onto cells of a second fly-eye lens. When an area to be used on a two-dimensional SLM is formed in a rectangular, the lens cells of the fly-eye lens are formed in a similar configuration to the area to be illuminated in order to image images which are on the lens cell. It is designed so that the size of the arc image of the lamp is equal to or smaller than the size of the second fly-eye lens. Actually, however, it is difficult for all light source images to enter the lens cells because of the size of light source (the size of light-emitting portion of the lamp, i.e., the arc size), spread of light and aberration of lenses. For this reason, there arise problems in that an optical performance is deteriorated, illumination efficiency is decreased and uniformity of illumination is deteriorated.
In view of the above-described facts, an object of the present invention is to provide an exposure apparatus which is capable of obtaining high illumination efficiency and performing uniform exposure.
SUMMARY OF THE INVENTION
The present inventors noted that a light source which has a light-emitting portion substantially similar to the configuration of lens cells of a fly-eye lens (the configuration of the light-emitting portion of a rod), i.e., the contour configuration of an exit surface of an optical integrator can guide most of light emitted from the light-emitting portion to an illumination area and improve illumination efficiency and illumination uniformity. The light-emitting portion in which end portions of optical fibers are bound as a bundle is usually formed in a hexagonal configuration (substantially circular configuration) as illustrated in FIG. 10 . The present inventors found that the configuration of the light-emitting portion could be freely formed, and as the result of diligent study, arrived at the present invention.
According to a first aspect of the present invention, there is provided an exposure apparatus including: a light source; an optical integrator to which light is supplied from the light source; and a two-dimensional spatial light modulator illuminated by light which has transmitted the optical integrator, wherein the light source includes an optical fiber bundle in which a plurality of optical fibers are arranged and light is emitted from the plurality of optical fibers, and the configuration of a light-emitting area formed at the end portion of the optical fiber bundle is, as seen from a light-emitting side, substantially similar to the contour configuration of the light exit surface of the optical integrator.
An optical fiber bundle refers herein to as an end portion in which end portions of a large number of optical fibers are bound. The optical fiber bundle may be formed in any configurations.
In order to supply light to the entering side of the optical fiber bundle, a lamp may be used or an LD (laser diode) may be used. When an LD is used, the LD is coupled to the entering side of the optical fiber. Alternatively, a plurality of LDs may be coupled to an optical fiber. This can increase the power of light while maintaining decreased Etendue. Further, a broad area type laser diode array including a plurality of emitters may be used.
In accordance with the first aspect of the exposure apparatus of the present invention, most of light emitted from the optical fiber bundle end portion can be guided to an illumination area to be illuminated by light reaching the two-dimensional spatial light modulator. Thus, high illumination efficiency can be obtained and uniform exposure can be realized.
The optical integrator is usually a fly-eye type or a rod type.
As the number of optical fibers is increased, the size of the optical fiber bundle end portion increases. Namely, Etendue at the light source side increases. If Etendue at the light source side is larger than that at the side of the two-dimensional spatial light modulator, illumination efficiency is decreased. For this reason, in the case of a large number of optical fibers, a diameter of a core or a clad of each of the optical fibers is decreased, so that a decrease in illumination efficiency can be prevented.
When a DMD is used as the two-dimensional spatial light modulator, light is entered in a tilted manner by a predetermined angle with respect to the optical axis of each of mirror surfaces of the DMD from a direction in which the mirrors are tilted (i.e., light is entered from a predetermined diagonal direction of the mirror surface). Thus, even if the configuration of the optical fiber bundle end portion is, as seen from the light emitting side, a rectangular configuration for example, a configuration obtained by deforming the rectangular is provided on each of the surfaces of the DMD. Nevertheless, because the amount of deformation is small, this configuration may be considered as a substantial rectangular configuration. Accordingly, in the case of using a DMD as the two-dimensional spatial light modulator, the configuration of the optical fiber bundle end portion can be, as seen from the light emitting side, substantially similar to the contour configuration of the exit surface of the optical integrator.
Because the DMD is not deteriorated by UV light unlike an LCD (liquid crystal display), a photosensitive material with high sensitivity for UV light can be exposed with high illumination efficiency.
According to a second aspect of the present invention, there is provided an exposure apparatus including: a light source device; an optical integrator to which light is supplied from the light source device; and a two-dimensional spatial light modulator illuminated by light which has transmitted the optical integrator, wherein the light source device includes a light source portion and an optical fiber bundle in which a plurality of optical fibers coupled to the light source portion are arranged and light is emitted from the plurality of optical fibers, and the configuration of light-emitting area formed at an end portion of the optical fiber bundle is, as seen from the light-emitting side, substantially similar to the contour configuration of the light-emitting surface of the optical integrator.
In accordance with a third aspect of the exposure apparatus of the present invention, there is provided an exposure apparatus including a plurality of exposure heads, wherein each of the plurality of exposure heads includes a light source, an optical integrator to which light is supplied from the light source, and a two-dimensional spatial light modulator illuminated by light which has transmitted the optical integrator, and the light source includes an optical fiber bundle in which a plurality of optical fibers are arranged and light is emitted from the plurality of optical fibers, and the configuration of light-emitting area formed at an end portion of the optical fiber bundle is, as seen from the light-exiting side, substantially similar to the contour configuration of the light-exiting surface of the optical integrator.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view illustrating an exterior of an exposure apparatus according to an embodiment of the present invention.
FIG. 2 is a perspective view illustrating a structure of a scanner for the exposure apparatus according to the embodiment of the present invention.
FIG. 3A is a plan view of an exposed area formed on a photosensitive material.
FIG. 3B is a plan view illustrating the arrangement of exposure heads in an exposed area.
FIG. 4 is a schematic view illustrating a structure of an exposure head of the exposure apparatus according to the embodiment of the present invention.
FIG. 5 is a plan view of a set illumination area on a two-dimensional SLM in the exposure apparatus according to the embodiment of the present invention.
FIG. 6A is a front view of an optical fiber bundle end portion in the exposure apparatus according to the embodiment of the present invention.
FIG. 6B is a schematic view of an optical fiber coupled to an LD.
FIG. 6C is a schematic view of an optical fiber coupled to a plurality of LDs.
FIG. 6D is a schematic view of an optical fiber coupled to an LD array.
FIG. 7 is a schematic view illustrating a modified example for the exposure head in the exposure apparatus according to the embodiment of the present invention.
FIG. 8 is a schematic view for explaining the principle of Etendue.
FIG. 9A is a schematic view for comparing positions of beams entering a DMD to a scanning line emitted from the DMD in the case that the DMD is not arranged in a tilted manner.
FIG. 9B is a schematic view for comparing positions of beams entering a DMD to a scanning line emitted from the DMD in the case that the DMD is arranged in a tilted manner.
FIG. 10 is a front view of a conventional optical fiber bundle end portion.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described hereinafter by examples. An exposure apparatus 142 according to an embodiment of the present invention comprises, as illustrated in FIG. 1 , a flat plate shaped stage 152 which attracts a sheet shaped photosensitive material 150 on its surface so as to hold the same. Disposed on the top surface of a thick plate shaped mount 156 supported by four legs 154 are two guides 158 extending along a direction in which the stage is moved. The stage 152 is disposed so that its longitudinal direction is along the direction in which the stage is moved, and reciprocably supported by the guides 158 . The exposure apparatus 142 is provided with an unillustrated driver for driving the stage 152 along the guides 158 .
A gate 160 with a U-shaped configuration is provided at the central portion of the mount 156 so as to bridge over a movement path for the stage 152 . End portions of the gate 160 are respectively fixed to side surfaces of the mount 156 . A scanner 162 is provided on one side of the gate 160 , and a plurality of (e.g., two) detection sensors 164 for detecting leading and trailing edges of the photosensitive material 150 are provided on the other side of the gate 160 . The scanner 162 and the detection sensors 164 are mounted to the gate 160 so as to be disposed in a fixed manner above the movement path for the stage 152 . The scanner 162 and the detection sensors 164 are connected to an unillustrated controller for controlling such components.
The scanner 162 comprises, as illustrated in FIGS. 2 and 3B , a plurality of (e.g., 14) exposure heads 166 arranged in a substantial matrix of m rows and n columns (e.g., three rows and five columns). According to this example, only four exposure heads 166 are arranged on the third row because of the relationship with the width of the photosensitive material 150 . An exposure head 166 ij indicates an exposure head arranged in the j-th column on the i-th row. The exposure heads have the same structure.
Each of exposure areas 168 by the exposure heads 166 is formed in a rectangular shape with its short side being along a sub-scanning direction V. Thus, in accordance with movement of the stage 152 , a band shaped exposed area 170 is formed on the photosensitive material 150 for each of the exposure heads 166 . An exposure area 168 ij indicates an exposure area formed by an exposure head arranged in the j-th column on the i-th row.
As illustrated in FIGS. 3A and 3B , for the purpose of arranging the band shaped exposed areas 170 along a direction perpendicular to the sub scanning direction without intervals therebetween, the exposure heads linearly arranged on the respective rows are shifted in an arrangement direction thereof by a predetermined interval (multiplication of a natural number and the long side of an exposure area, in this embodiment, twice the long side of the exposure area). Thus, an unexposed portion between the exposure area 168 11 and the exposure area 168 12 on the first row can be exposed by the exposure area 168 21 on the second row and the exposure area 168 31 on the third row.
[Structure of Exposure Head]
Because the exposure heads 166 11 to 166 mn have the same structure, the structure of one of them will be described hereinafter.
As illustrated in FIG. 4 , the exposure head 166 comprises, as a light source, a large number of optical fibers 174 with their light-emitting end portions being bundled to be an optical fiber bundle end portion 174 E, and an LD coupled to the large number of optical fibers 174 .
Further, the exposure head 166 comprises an optical integrator 176 as an illumination optical system that light emitted from the optical fiber bundle end portion 174 E enters. The optical integrator 176 comprises a collimator lens 178 for converging the light from the optical fiber bundle end portion 174 E, two fly-eye lenses 180 A and 180 B for successively transmitting the converged light which has transmitted the collimator lens 178 , and a field lens 182 .
The exposure head 166 is provided with a two-dimensional SLM (two-dimensional spatial light modulator) 186 for modulating the light which has transmitted the field lens 182 .
As illustrated in FIG. 5 , a set illumination area 190 intended for illuminating the two-dimensional SLM 186 is formed in a rectangular shape. As illustrated in FIG. 6A , the optical fiber bundle end portion 174 E forms, as seen from the light-emitting side, a light-emitting area 192 which is substantially similar to the set illumination area 190 . Thus, light from the optical fiber bundle end portion 174 E can be utilized as illumination light without being wasted, and high illumination efficiency can be obtained.
In order to supply light to the entering side of the optical fiber bundle, a lamp may be used or an LD (laser diode) may be used. When an LD is used, the LD is coupled to the entering side of the optical fiber ( FIG. 6B ). Alternatively, a plurality of LDs may be coupled to an optical fiber ( FIG. 6C ). This can increase the power of light while maintaining decreased Etendue. Further, a broad area type laser diode array including a plurality of emitters may be used ( FIG. 6D ).
There may be provided an exposure apparatus having, instead of a fly-eye lens type exposure head, a rod type exposure head utilizing a rod 194 made of glass as illustrated in FIG. 7 . This can simplify the structure of the apparatus.
[Characteristics of Illumination Optical System and Arrangement Position Thereof]
FIG. 4 illustrates an example of simplified view of the illumination optical system. With respect to the fly-eye lens 180 A, the size of its lens cells is S 1 , the number of lens cells is N 1 , its longitudinal length is A 1 and its focal distance is ML 1 F. Its converging size is Z 1 (=2×ML 1 F×NA 1 ). With respect to the fly-eye lens 180 B, its lens cell size S 2 (=S 1 ), the number of lens cells N 2 (=N 1 ) and its longitudinal direction length A 2 (=A 1 ) are the same as those in the fly-eye lens 180 A. Its focal distance is ML 2 F. The longitudinal length FLD of the field lens 182 is substantially equal to A 2 . The two-dimensional SLM 186 is arranged so that the focal distance FLF of the field lens 182 is substantially equal to the distance L 4 from the fly-eye lens 180 B to the two-dimensional SLM 186 .
The distance L 1 from the optical fiber bundle end portion 174 E to the collimator lens 178 and the distance L 2 from the collimator lens 178 to the fly-eye lens 180 A are equal to the focal distance CL 2 F of the collimator lens 178 . The distance L 3 from the fly-eye lens 180 A to the fly-eye lens 180 B is equal to the focal distance ML 1 F of the fly-eye lens 180 A.
Assuming that a length of the optical fiber bundle end portion 174 E in one direction is A 0 , the radiation angle of light from the optical fiber bundle end portion 174 E is NA 0 and a converging angle toward the fly-eye lens 180 A is NA 1 . A basic formula for the illumination system can be represented by the following.
A 0 · NA 0 = A 1 · NA 1
(i.e., A 0 · NA 0 = N 1 · S 1 · NA 1 )
An imaging characteristic can be represented by the following formula.
1 /L 3+1 /L 4=1 /ML 2 F
(i.e., 1 /ML 1 F +1 /L 4=1 /ML 2 F )
A magnification characteristic can be represented by the following formula.
ACS/S 1= L 4/ L 3
(i.e., ACS/S 1= L 4/ ML 1 F )
A converging characteristic can be represented by the following formula with a converging size (diameter) by the fly-eye lens 180 A being Z 1 .
Z 1=2 ·ML 1 F·NA 1
Illumination FN 0 can be represented as follows.
SFN 0 =FLF/FLD (≈ L 4/ L 2)
[Concept of Etendue]
Illuminating an SLM (spatial light modulator) means imaging an image of a light source onto the SLM. When an optical magnification is indicated by β, as illustrated in FIG. 8 , an area S 2 of an image is in proportion to β 2 (S 2 =β 2 S 1 ), and an angle θ formed by light and an optical axis is in inverse proportion to the magnification β (θ 2 =θ 1 /β) Namely, the following equation can be derived.
S 1 θ 1 2 =S 2 θ 2 2
Because a solid angle Ω is substantially in proportion to θ 2 , the following expression can be derived.
Ω 1 S 1 ≈Ω 2 S 2
Namely, the product of the area of a light source and the solid angle is constant. Strictly speaking, transmission of luminous flux by a perfect lens (with 100% of transmittance and no aberration) 198 can be represented as follows.
luminous flux: e=∫S ∫Ωcos θ· dS·dΩ
When θ is sufficiently small (F is equal to or larger than 2.5), cos θ≈1. Thus, the following expression can be given.
luminous flux: e≈Ω 1 S 1 ≈Ω 2 S 2
“ΩS” in the expression is Etendue. Assuming an ideal optical system with 100% of transmittance and no aberration, Etendue is conserved (It is known that Etendue is conserved even if a conjugate relationship is not provided.).
The light source B in FIG. 8 is assumed to be a two-dimensional SLM. If Etendue of the light source A is smaller than that of the two-dimensional SLM, illumination with significantly high efficiency can be realized.
(Example of Calculation)
Etendue at the light source side is indicated by Es.
(1) Case of Discharge Lamp with 4 mm of Arc length
When the light source is a cylinder with a diameter of 1 mm and a length of 4 mm, and light is emitted in an isotropic manner from its side surface, the following expression is derived. (Etendue is large.)
Es =π·1·4·2π≈80 mm 2 ·str
(2) Case of Fiber Light Source
When the size of bundle exit portion is 0.7×0.7 mm and NA is 0.2 (≈11.5 deg), the following expression is derived. (Etendue is significantly small.)
Es =2π·(1−cos 11.5)·0.7·0.7≈0.06 mm 2 ·str
EXAMPLES
A description will be given by tanking the case of using a DMD as the two-dimensional SLM 186 as an example. As illustrated in FIGS. 9A and 9B , a DMD 200 serving as the two-dimensional SLM is provided for each of the exposure heads 166 11 to 166 mn . The DMD 200 modulates an incident light beam in accordance with image data on a pixel-by-pixel basis.
FIG. 9A illustrates scanning loci of real images (beam spots BS) of pixel portions in the case in which the DMD 200 is not tilted with respect to a main scanning direction U. FIG. 9B illustrates scanning loci of beam spots BS in the case in which the DMD 200 is tilted with respect to the main scanning direction U. The DMD 200 is preferably arranged so as to be tilted a little so that a predetermined angle θ (e.g., 0.1° to 1°) is formed by a direction of its side and the main scanning direction U.
In the DMD 200 , a large number of (e.g., 600) pixel columns, in each of which a large number of (e.g., 800) pixel portions are arranged along a longitudinal direction (a direction of row), are arranged in a transverse direction. As illustrated in FIG. 9B , by tilting the DMD 200 , a pitch P 2 between scanning loci (scanning lines) of beam spots BS emitted from pixel portions becomes narrower than a pitch P 1 between scanning lines in the case that the DMD 200 is not tilted, resulting in a significant improvement in resolution. Because the angle at which the DMD 200 is tilted is small, a scanning width W 2 in the case that the DMD 200 is tilted is substantially the same as a scanning width W 1 in the case that the DMD 200 is not tilted.
The substantially same position (dot) on the same scanning line is exposed repeatedly (subjected to multiple exposure) by different pixel columns. Because of such multiple exposure, a fine amount at an exposed position can be controlled and highly fine exposure can be realized. Seams between a plurality of exposure heads arranged along the main scanning direction U can be jointed by controlling fine amounts at exposed positions without steps being formed therebetween. At this time, the amount of deformation is small.
As described above, in accordance with this example, the DMD 200 which is not deteriorated by UV light unlike an LCD (liquid crystal display) is provided as a two-dimensional SLM. Thus, a photosensitive material which is sensitive to UV light can be uniformly exposed with high illumination efficiency.
Although the embodiments of the present invention have been described with examples, the examples are merely an illustration and can be variously changed within the scope that falls within the spirit of the invention. Further, it is needless to say that the scope of the present invention is not limited by the example.
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An object of the present invention is to provide an exposure apparatus which is capable of obtaining high illumination efficiency and performing uniform exposure. In accordance with the exposure apparatus that includes a light source, an optical integrator to which light is supplied from the light source and a two-dimensional spatial light modulator illuminated by light which has transmitted the optical integrator, an optical fiber bundle end portion for emitting light to the optical integrator is provided in the light source, and the light-emitting area of the optical fiber bundle end portion is, as seen from the light-emitting side, substantially similar to the contour configuration of light-emitting surface of the optical integrator. Thus, most of the light emitted from the optical fiber bundle end portion can be illuminated onto a set illumination area. As a result, high illumination efficiency can be obtained and uniform exposure can be realized.
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FIELD OF THE INVENTION
This invention relates to apparatus for filtering and disinfecting water from a variety of sources to produce potable water and for oxidizing and removing hazardous chemicals in the water.
BACKGROUND OF THE INVENTION
Raw water from fresh water sources such as wells, ponds, streams, lakes, etc. varies widely in quality and must generally be treated to make it potable. Often, it is necessary to treat water in remote areas for limited periods, such as during a military deployment, a remote short term construction project, after damage to a local permanent purification system, etc.
In addition, due to tanker truck spills, hazardous material leaks, etc. there are often needs for neutralizing and/or removing hazardous chemicals from the environment. In addition, where surface water is contaminated, decontamination and return to the surface is required without extensive treatment to the point where the water is potable.
A number of different water purification systems have been developed for treating water from a lake or river where the water is not highly contaminated . Generally, water is simply clarified, filtered to remove particulates and treated with chlorine.
Where both decontamination and disinfection of poor quality water is required, treatment with ozone is most effective. Ozone has been used for more than one hundred years to treat potable water supplies. Ozone is extensively used in municipal water plants in Europe, largely because of the poor quality of the water supplies. Ozone also provides superior disinfection and excels in the control of taste and color.
The extremely high effectiveness of ozone is due to its great oxidizing power. Ozone acts to oxidize pollutants and as a germicidal agent for microorganisms. Resistant sporulating types of bacteria are destroyed by ozone along with pathogenic and saprophytic organisms likely to be encountered in water. Ozone is used in the treatment of drinking water for bacterial disinfection, destruction of viruses and protozoans, increasing settleability characteristics, removal of algae, sulfides, cyanides, trihalomethane precursors organics, detergents, pesticides, phenols and humnic, fulvic and tannic acids. Soluble iron, manganese and other heavy metals are oxidized to insoluble forms that can be filtered from the water. Large, complex organic compounds are oxidized into smaller more easily biodegradable molecules. With the removal of organic compounds comes removal of odor, color and taste in the water. Ozone has been recognized to be significantly more effective than chlorine as a germicide against bacteria, viruses and protozoans.
Various devices and methods have been developed for purifying drinking water and waste water, such as those described by Laraus in U.S. Pat. No. 4,250,040 and Bhargava in 4,256,574. Prior ozone treatment plants have tended to be large, fixed plants for treating water at a particular location over a long period.
Mausegrover et al. describe a truck mounted ozone water treatment apparatus in U.S. Pat. No. 5,427,693. This apparatus includes a process tank for holding contaminated water and an ozone generator using a venturi to inject ozone into a water stream directed from the process tank to an infusion chamber. While probably effective for small quantities of lightly contaminated water, no provision is made for effectively filtering the water or of altering the throughput sequence for varying contamination. Also, the apparatus does not appear to be capable of routine transport by fixed wing aircraft or helicopters, limiting its effectiveness due to lack of mobility.
Thus, there is a continuing need for a portable ozone type water treatment system having improved decontamination capability, effective filtration for water of varying quality and that can adjust throughput rates and intensity Of treatment to accommodate widely different water quality characteristics.
SUMMARY OF THE INVENTION
The above-noted problems, and others, are overcome in accordance with this invention by an ozone treatment system for potable water treatment and ground water or surface water remediation and which is self contained and readily portable.
In use, raw water is pressurized, typically by an external pump, and directed through a manifold to at least two independent parallel trains. The use of two or more independent trains allows one train to be shut down for maintenance, etc., while continuing operation of the remainder of the system. In each train, the water enters a passive centrifugal sand separator where large diameter matter is captured. Where a pressurizing pump is used, preferably large matter is captured in a pump strainer. Purging means is included for periodically purging the sand separator to waste.
The flow then enters a multistage, typically three stage, filter system. The filter stages include disposable filter cartridges of differing graded porosity. If desired, the filter cartridges may contain granulated activated carbon, ceramic polypropylene or resin bonded cellulose, depending on the treatment desired.
After leaving the filter system, the flow is injected with ozone gas through a venturi and enters a plug-flow contact system constructed of flexible tubing, the size and diameter of which is configured for maximum ozone gas contact over a selected range of flow.
A unique multi-stage secondary contact vessel receives the flow from the tubing. The secondary contact vessel includes a novel combination of perforated baffle-plates that serve as compartment separators. The baffle plate orifices are located to provide optimum ozone gas contact.
A fourth filter stage receives flow from the secondary contact vessel. The fourth filter stage contains cartridges having porosity and type selected in accordance with the desired levels of water quality in terms of final stage or precipitation turbidity removal. The fourth filter stage also acts as an ozone contact vessel, providing additional detention and ozone contact.
Both flow trains are combined after leaving the fourth filter stages of the separate trains and the combined flow passes to a manifold for delivery to storage or other uses. This water treatment system may be configured in either a rapid deployment mobile configuration or in a stationary configuration that is easily converted between potable water treatment and ground water or surface water remediation.
In the potable water treatment configuration, this system may be used to treat raw water from fresh water sources (wells, ponds, streams, lakes, etc.) of varying quality. The system may also be used in conjunction with an existing municipal or community water treatment system that has been contaminated and/or is not functioning properly. The system is capable of eliminating bacterial contamination, including removal or reduction of sporulating types of bacteria along with pathogenic and saprophytic organisms, including Cryptosporidium and related Giardia species as well as pathogenic viral materials. In addition, the system will remove or reduce color, taste, odor algae, sulfides, cyanides, trihalomethane precursors, detergents, pesticides, phenols, fulvic and tannic acids. Also, it will oxidize miscellaneous organic compounds, and soluble iron, manganese and other heavy metals. Large complex organic compounds will be oxidized into smaller more easily biodegradable molecules.
In the groundwater or surface water remediation configuration the system will, through oxidation, break down and destroy inorganic and organic chemicals such as chloroform, carbon tetrachloride, cis-1,2-dichloroethane, 1,1,2-trichloroethane, methylene chloride and many others in addition to those constituents listed in the preceding paragraph.
In the rapid deployment mobile configuration the system is enclosed in a skid-mounted, sturdy but light weight container for easy transporting by ground vehicles, helicopters, cargo aircraft and waterborne vessels such as barges. This configuration is particular useful by military organizations during rapid deployments, and by emergency management agencies in natural disasters such as earthquakes or floods where normal water supplies are disrupted, etc.
Where the purpose of treating a given supply of water is for groundwater and/or surface water remediation, rather than to produce potable water, filter cartridges may be omitted from the initial filter stages. The ozone injector line may be relocated to inject ozone into the flow line in advance of the filter housings to provide additional ozone contact time prior to flow entering the plug-flow and subsequent secondary contact vessel.
If desired, fittings may be provided to enable the parallel multi-train configuration to be converted into an in-line series where large increases in the level of ozone applied and ozone contact time are desired.
While the system could be operated manually, for most efficient operation a solid state programmable logic controller of the sort available from IDEC programmed in a conventional manner to take flow, turbidity, ozone residual, etc. readings from appropriate points, as discussed below, and control operation is preferred. Typical monitors that would be used in the control and operation of the system include a leak detection monitor, a turbidity analyzer, a dissolved ozone monitor, etc.
BRIEF DESCRIPTION OF THE DRAWINGS
Details of the invention, and of preferred embodiments thereof, will be further understood upon reference to the drawing, wherein:
FIGS. 1A and 1B when combined provide a schematic hydraulic diagram of a multiple parallel train potable water treatment system of this invention;
FIGS. 2A and 2B when combined provide a schematic hydraulic diagram of the water treatment system of FIGS. 1A and 1B optimized for ground water and/or surface water remediation;
FIG. 3 is an elevation view, partly cut-away, of an ozone secondary contact vessel; and
FIG. 4 is a section view taken on line 4--4 in FIG. 3, showing a baffle plate.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1, there is seen a schematic hydraulic diagram showing the multi-train embodiment of the water treatment system. Pressurized water to be treated enters through inlet 10. Typically, the water may come from a pressurized city system or may be pumped. Where the water is pressurized by an external pump (often of the submersible type) and the water and may contain large particles, a conventional strainer is preferably used with the pump. A typical pump could be Model 18G530 stainless steel submersible pump from the Gould Company. The pump should be suitable for submersion in a shallow, rapid current water source and have a large external object inlet screen.
The water flow is divided at point 12 into two separate first and second trains. With a two train, parallel, arrangement, each train may be operated independently so that the operator may perform maintenance such as periodic injector cleaning, filter cartridge examination and/or replacement on one train without ceasing production. If desired, three or more parallel trains could be used, although generally two trains provide an optimum combination of light weight, low system complexity and system efficiency.
Water passes to first and second centrifugal sand separators 12 and 14 in the first and second trains, respectively, through ball valves 13 and 15, respectively. Suitable sand separators are available from Yardney Water Management Systems, Inc. under the Model R7V designation. Periodically first and second sand separators 12 and 14 are manually purged of particulate matter through the common waste drain line via a ball valve 20 and aerosols through ball valve 22 and air relief valve 24 and collector 26. The purged water and sand reaches common drain lines 16 and 18 through ball valves 20 and 22 and aerosols are expelled via air release valves 24 and 26. Collectors 28 and 30 redirect moisture to common drain lines 16 and 18.
Water flow cleaned of sand from sand separators 12 and 14 passes through lines 32 and 34, respectively, to a first train consisting of filter stages 36, 38 and 40 and a second train consisting of filter stages 42, 44 and 46. A by-pass arrangement including bypass line 50 and ball valves 52 is provided so that flow from either (or both) sand separators 12 and 14 can be directed to either filter train.
Each filter stage 36-46 is typically a stainless steel vessel incorporating disposable filter cartridges (such as depth-type, pleated, wound, etc.) of differing graded porosity. These cartridges may be supplemented, when desired, with granulated activated carbon or ceramic cartridges. Typically such filter housings and cartridges may be obtained from Cuno, Inc. Ball valves 48 are provided to allow purging or back flushing of each filter stage 36-46. Pressure gages 54 are provided at each filter stage 36-46 to show pressure in the stage and pressure drop across the filter media in each stage. A differential pressure switch 56 is provided across each pair of filter stages 36 and 38 and stages 42 and 44. If the pressure differential exceeds a pre-programmed pressure target, usually indicating a need for filter cartridge replacement, switch 56 will trigger an alarm in the control system which can shutdown the system.
For the system to operate efficiently, system temperature must be maintained below a predetermined level. Both oxygen preparation and ozone generation lose efficiency once the ambient temperature exceeds 90° F. An air conditioner unit 58, typically a K2AC12WNP47 from Kooltronics is preferably included. Water is directed to air conditioner 58 from the outlet line of filter stages 38 and/or 46 via lines incorporating check valves 64 and 66 and pressure relief valve 68. An air conditioner drain line 67 and condensate drain line 69 drain waste water from air conditioner 58 to common waste line 16.
If freezing temperatures are likely, a conventional heater (not shown) is included in the housing for the system. Also, if high humidity conditions are likely, preferably regenerating desiccant material may be included in the control and processing compartments.
The water flow departing the second filter stages 40 and 46 passes through flow control valves 70 and flow meters 72, then enters venturi-type ozone injectors 74 and 76, respectively. Typical such injectors include those available from the Mazzie Injector Corporation. Any suitable source of industrial grade oxygen and any suitable ozone generator 78 may be used. Typical oxygen generators take in ambient air, compress it, then feed the compressed gas into a series of pressure swing absorption molecular sieve containers that both dry the gas and remove nitrogen and argon. Such a generator delivers approximately 95% pure oxygen to the ozone generator. Preferably, ozone is generated by an air-cooled, solid-state, high frequency, corona discharge generator. Typical of such preferred ozone generators is the ozone generator of the sort available from Pacific Technology, Inc. Under the G22 or SG22 designations.
Flow from ozone generators 78 passes to a plug-flow contact system 80 constructed of flexible tubing. Tygon inter-braid tubing is preferred. While any suitable length and diameter may be used, for best results lengths of from about 130 to 150 feet and diameters of from about 1 to 2 inches are preferred.
The water flow from each contact system 80 then enters a multi stage secondary contact vessel 82. Each vessel 82 has a series of perforated baffle plates forming a series of compartments though which the water flows from one end of the vessel to the other to provide optimum ozone gas/water contact. Details of vessels 82 is provided below in conjunction with the description of the vessels as illustrated in FIGS. 3 and 4. A line 81, controlled by ball valve 83, can be used to drain each vessel 82 to common waste lines 16 and 18 when desired. Each vessel 82 is also connected to a pressure release valve 85 and a pressure gauge 54.
From contact vessels 82 flow is directed to fourth filter stages 84 through lines 86 and 88. Flow from both contact vessels combines at line 90, then divides and flows to fourth filter stages 84. A sample port 92 and ozone sensor probe 94 in line 90 are used to monitor the quality of the water at this point. Filter stages 84 contain cartridges of a selected porosity and type, selected in accordance with the desired level of water quality. In this process, fourth filter stages 84 also act as water/ozone contact vessels, offering additional detention and ozone contact. Valves 48 are provided to purge filters 84 as needed. After leaving fourth filter stages 84 the flows are recombined through lines 96 and 98 at manifold 100 for delivery to purified water storage, waste or other uses through lines 101. The delivery destination is PLC controlled, based on pre-selected quality control parameters.
Manifold 100 preferably includes a sample port 102, a turbidity sensor 104, a pressure gauge 54 and solenoid valves 107 in output lines 101.
In some cases, it may be desirable to insert an ultra-violet light sub-system 106 following the secondary contact vessels 82, preferably in storage outlet line 101. The additions of short, high intensity bursts of ultraviolet light cause the production instantaneous and short duration free hydroxyl radicals that add an oxidation boost to the remediation process which can be highly desirable where the water contains a high level of contaminants.
An off-gas ozone destruction unit 108 is provided to collect, through lines 109, off-gas from the tops of secondary contact vessels 82. A thermally operated destruct unit of the sort available from Pacific Technology, Inc. under the D412 designation is included in unit 108, with the resulting environmentally acceptable gas vented through line 110 to the atmosphere. A water trap 112 is provided to collect any water accumulation from lines 109 prior to off-gas destruct unit 108.
FIG. 2 is a schematic hydraulic circuit diagram of a variation of the system shown in FIG. 1 that is optimized for surface or ground water remediation where the primary purpose is to remove volatile organic contaminants. The water produced will be returned to the surface or underground and need not be potable.
Since this is a variation on the FIG. 1 system, most components are common to both and are identified with the same reference numbers. For clarity, the water flow path in the FIG. 2 variation is shown in heavy lines.
Ball valve 13 is closed to isolate one train of the dual train, parallel system of FIG. 1 from water inlet 10. Contaminated water flows from inlet 10 to second sand separator 14, then to filter stages 42, 44 and 46 in seriatim. The flow then passes to ozone injection system 114. For maximum ozone injection, dual parallel ozone injectors 76, each fed by an ozone generator 78 are required. Water then flows through an elongated tubular plug flow contactor 80 and to secondary contactor 82a.
Bypass line 114 connects an outlet from secondary contact vessel 82a to an inlet into secondary contact vessel 82b. Greater ozone volume and longer contact is highly desirable wherein decomposition of large molecule organic contaminants is necessary. Treated water from secondary contact vessel 82b then flows through lines 86 and 90 and is divided between inlets to two fourth filter stages 84. The water then passes to outlet line 101. If desired, a UV station 106 can be included in the outlet line 101.
The arrangement of FIG. 2 is preferred for surface and ground water remediation where the water is heavily contaminated with volatile organic contaminants and the water is to be returned to the environment. Massive ozone injection in conjunction with UV radiation will result in the destruction or reduction to acceptable levels of the susceptible volatile organic contaminants.
A novel secondary ozone/water secondary contactor vessel 82 is illustrated in FIGS. 3 and 4.
Basically, secondary contact vessel 82 is cylindrical, formed from any suitable material, such as stainless steel, glass fiber reinforced polyester resins, poly vinyl chloride, etc. While secondary contact vessel 82 may have any suitable dimensions, typically, the height will be from about 60 to 80 inches and the inside diameter from about 12 to 20 inches with an inside diameter of about 16 inches and inside height of about 63 inches being optimum. Top and bottom end closures 120 and 122, respectively, are typically formed from reinforced polyester or polyvinyl chloride resins. Preferably, an air relief valve 124, a pressure gauge 126 and a pressure relief valve 128 are provided through top closure 120.
A plurality of spaced baffle plates 130 are installed across the interior of secondary contact vessel 82, forming compartments 132 therebetween. While any suitable number and spacing of baffle plates 130 may be used, generally from 4 to 8 uniformly spaced plates is preferred. For best results, six equally spaced baffle plates 130 are used. The baffle plates may be formed from any suitable material reinforced polyester or polyvinyl chloride resins. Preferably baffle plates 130 are formed from 0.5 inch thick schedule 80 polyvinyl chloride.
Each baffle plate 130 has a pattern of holes 134 therethrough. While any suitable size, number and pattern of perforations 134 may be used, for optimum contact between injected ozone and flowing water, the holes should have diameters of from about 0.2 to 0.35 inch and should have the pattern shown. The optimum pattern of holes 134 has 45 holes through each baffle plate 130 arranged in fifteen radial rows of three substantially equally spaced holes. The hole pattern can also be thought of as preceding three substantially equally spaced, generally circular, rows of fifteen holes 134. Around each row, each third hole 134 is spaced outwardly relative to the other holes.
Where the diameter of a baffle plate is equal to the inside diameter of the contactor, e.g., 16 inches, the inner hole circle will have a diameter of about 2.5 inches, with every third hole 134 spaced about 3 inches from the secondary contact vessel center point 135. The second generally circular row away from center point 135 has a diameter of about 4.5 inches, with every third hole 134 spaced about 5 inches from the secondary contact vessel center point 135. The third generally circular row away from 135 has a diameter of about 6.5 inches, with every third hole 134 spaced about 7 inches from the secondary contact vessel center point 135. This pattern provides superior ozone/water contact, as random alignment of the baffle plates precludes the potential for short-circuiting of the ozonated water column, insuring maximum interface of the gas and liquid and maximum contact time for the oxidation processes to occur. For best results, the holes 134 in each baffle plate 130 are not aligned with the holes in the adjacent baffle plates. Preferably, the rotational offset from plate to plate is about 30° to 40°. A rotational offset of about 36° has been found to be optimum in most cases.
A water inlet 138 is provided for directing water from line 80 into the lowermost chamber 132. A water outlet 136 is provided for directing water out of the uppermost chamber 132 to filter stage 84, as shown in FIGS. 1 and 2.
While certain specific relationships, materials and other parameters have been detailed in the above description of preferred embodiments, those can be varied, where suitable, with similar results. Other applications, variation and ramifications of the present invention will occur to those skilled in the art upon reading the present disclosure. Those are intended to be included within the scope of this invention as defined in the appended claims.
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A water purification system which filters particulates from the water and treats organic contaminats with ozone. The incoming contaminated water flow is divided, with half passing through each of two filter and ozone contact systems. Initially, each stream is passed though a sand separation device to remove large high density particulate mater, then through a multi-stage filter arrangement incorporating disposable filter cartridges. Ozone is injected into each stream leaving the filter system. The flow passes through elongated plug-flow tubing to assure optimum water/ozone contact, then enters a multi-compartment secondary contactor having a series of perforated baffle plates through which the water flows to assure complete ozone/water contact. Finally, each stream passes through a final filter stage, then the streams are combined and pass to storage or a purified water outlet. If desired, the entire flow can be passed through the combined ozone injection system, a selected filtration system and the water/ozone gas contact system.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates a new spray device for the fine spray dispersion of, e.g., liquids such as water including mineral or thermal spring water, comprising a propellent gas mixture.
2. Discussion of the Background
The beneficial physiological and therapeutic properties of mineralized waters, such as mineral and thermal spring waters, have been known for quite some time. Mineralized waters contain beneficial mineral salts and trace elements. Application of mineralized waters as a fine mist to the skin provides the skin with an even distribution of the beneficial mineral salts and trace elements of mineralized waters. In addition, such an application provides an overall feeling of freshness.
Portable personal aerosol containers were developed so that the public could take advantage of the beneficial properties of various waters. For example, as described in F. Clanet, Presse thermale et climatique, 1986, 123, No. 1,: “Le conditionnement des eaux sulfurées en emballages aérosols permettant leur utilisation individuelle” [translation: “The packaging of sulphur waters in aerosol containers would permit their personal use”].
The use of a gag for pressurizing an aerosol container, is well known in the art.
Nitrogen is one gas commonly used to pressurize aerosal containers. However, the pressure of nitrogen gas can cause water soluble ions of high ion content mineralized waters, in particular waters having a high concentration of carbonate or bicarbonate ions, to precipitate. As a result, the chemical composition of the mineralized water is modified which, in turn, can modify the waters' properties and ultimately, the waters' effect on the skin. Furthermore, the ion precipitation increases the risk of blockage of the exit nozzle of the aerosol container which would render the aerosol container inoperable.
Special Medicinal Patent No. 3574 describes the use of carbon dioxide gas in aerosol containers equipped with mechanical propulsion systems. However, when carbon dioxide is used in an aerosol container unequipped with a mechanical propulsion system, several problems result. Instead of a fine spray, which is defined as a cloud of particles having a size of between 50 μm and 120 μm, the aerosol container produces water droplets or a liquid jet. Also, liquid leaks form at the atomizer passage of the aerosol container. A spray device that produces such problems is not suitable for marketing.
Also well known in the art is the need to decontaminate the aerosol container once the aerosol container has been pressurized and filled with gas and mineralized water to prevent microbial growth in the water. Decontamination is usually achieved by physical methods, such as heat or ionizing treatments. However, such decontamination methods are very expensive.
Therefore a need still exists for a portable personal aerosol container or spray device which overcomes such problems as ion precipitation, poor spray dispersion and leakage. Furthermore, an alternate and less-expensive decontamination process for a spray device is also needed.
Applicants have surprisingly discovered that a personal aerosol or spray device pressurized by a gas mixture comprising nitrogen and carbon dioxide overcomes these problems and, in addition, provides a liquid, such as water, that is better tolerated by the skin.
SUMMARY OF THE INVENTION
Accordingly, one object of the present invention is to provide a spray device pressurized by a gas mixture comprising nitrogen and carbon dioxide.
Another object of the present invention is to provide a spray device pressurized by a gas mixture comprising nitrogen and carbon dioxide for the application of a liquid or atomizable composition.
Another object of the present invention is to provide a spray device pressurized by a gas mixture comprising nitrogen and carbon dioxide for the application of a liquid or atomizable composition, such as mineralized water, which overcomes the problems associated with previous aerosol containers such as ion precipitates and liquid jet.
Another object of the present invention is to provide a spray device pressurized by a gas mixture comprising nitrogen and carbon dioxide for the application of mineralized water which not only reduces the bacteria content of the mineralized water contained in the spray device, but can also maintain very low levels of bacteria in the water for a lengthy period of time without needing to undergo a physical decontamination process.
Still another object of the present invention is to provide a spray device pressurized by a gas mixture comprising nitrogen and carbon dioxide for the application of mineralized water wherein the gas mixture adjusts the pH of the contained mineralized water close to that of the skin.
Still another object of the present invention is to provide a spray device pressurized by a gas mixture comprising nitrogen and carbon dioxide for the application of a liquid or atomizable composition, such as mineralized water, wherein the liquid or atomizable composition can further comprise cosmetic and/or dermatological adjuvants.
The spray device of the present invention comprises a container, a propellent gas mixture, a valve and a means for atomizing.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The spray device of the present invention can be used in the application of a liquid or atomizable composition, preferably, of mineralized waters, more preferably, mineral or thermal spring waters. These waters can contain, inter alia, trace elements such as iron (Fe), manganese (Mn), copper (Cu), aluminum (Al) and arsenic (As), and dissolved minerals such as carbonate, bicarbonate (HCO 3 − ), sulfates (SO 4 2− ), thiosulfates (S 2 O 3 2− ), hydrogensulfide (HS − ), sodium (Na + ), potassium (K + ), lithium (Li + ), calcium (Ca 2+ ), magnesium (Mg 2+ ) and strontium (Sr 2+ ). It is known that these waters, depending upon the particular mineral and trace element content, can be used for therapeutic purposes such as moisturizing and desensitization of the skin or the treatment of certain dermatoses.
The mineral or thermal spring waters are, preferably, naturally occurring mineral or thermal spring waters or naturally occurring mineral or thermal spring waters enriched with additional dissolvable minerals and/or trace elements or enriched with aqueous solutions prepared from purified water (demineralized or distilled water) enriched with dissolvable minerals and/or trace elements.
Naturally occurring thermal spring or mineral waters for use in the spray device of the present invention are, preferably, water from Vittel, water from the Vichy basin, water from Uriage, water from La Roche Posay, water from La Bourboule, water from Enghien-les-Bains, water from Saint Gervais-les-Bains, water from Néris-les-Bains, water from Allevar-les-Bains, water from Digne, water from Maizières, water from Neyrac-les-Bains, water from Lons-le-Saunier, water from Eaux-Bonnes, water from Rochefort, water from Saint Christau, water from Les Fumades, water from Tercis-les-Bains or water from Avene.
The mineral or thermal spring waters for use in the spray device of the present invention can also be those with relatively high concentration of carbonates or bicarbonates such that precipitate formation is not observed. Mineral or thermal spring waters such as water from Vittel, water from the Vichy basin, water from Uriage, water from La Roche Posay, water from La Bourboule, water from Enghien-les-Bains or water from Les Fumades, contain a total concentration of carbonates or bicarbonates of greater than 360 mg/L, and, upon use, do not exhibit precipitate formation and the disadvantages associated therewith.
The liquid or atomizable composition, preferably mineralized water, contained in the spray device of the present invention can further contain cosmetic and/or dermatological adjuvants such as preservatives, antioxidants, fragrances, UV-screening agents, coloring materials, and hydrophilic or lipophilic active principles. The adjuvants should not effect the integrity of the liquid or atomizable composition, preferably mineralized water, or produce negative side effects once the liquid or atomizable composition, preferably mineralized water, is sprayed onto the skin. The adjuvants are preferably those that can be distributed in the form of a spray or can be atomized. In addition, the adjuvants are preferably those which do not interfere with the working of the spray device, in particular those that do not block the atomizer passage.
Coloring materials or colorants used in the present invention are those well known to those skilled in the art. The colorants can be inorganic or organic colorants or dyestuffs.
Fragrances for use in the present invention are those well-known to one skilled in the art. The fragrances can be natural or synthetic.
The hydrophilic or lipophilic active principles, which are preferably hydrophilic so that they can be dissolved in an aqueous lotion based on mineral water, can treat the skin and can be anti-aging active principles, anti-wrinkle active principles, moisturizers or humectants, depigmenting active principles, active principles for combating free radicals (radical oxygen species), nutritive active principles, protective active principles, restructuring active principles, toning active principles, anti-acne active principles, exfoliating active principles, emollient active principles. The active principles can also treat skin diseases, such as mycones, dermatitides, psoriasis and the like.
Anti-acne, anti-aging, anti-wrinkle, moisturizing or exfoliating active principles are those well-known to one skilled in the art and can, preferably, be α-hydroxy acids such as glycolic, lactic, malic and citric acids and the like.
The active principles are added to the liquid or atomizable composition, preferably, mineralized water in proportions appropriate for its intended purpose. Preferably, 0.01% to 10% by weight of the active principle with respect to the total weight of the composition is added. More preferably, 0.05-5% by weight, more preferably still, 0.1-1% by weight, and even more preferably 0.15-0.5% by weight of the adjuvant is added.
The propellent gas mixture employed in the spray device of the present invention is a mixture comprising nitrogen (N 2 ) and carbon dioxide (CO 2 ). Preferably, the propellent gas mixture consists essentially of N 2 and CO 2 .
Spray tests were conducted with spray devices pressurized by propellent gas mixtures comprising variable percentages by volume of nitrogen and carbon dioxide. The tests indicated that in order to prevent the formation of liquid jet at the end of spraying, the propellent gas mixture, preferably, contained greater than 30% by volume of nitrogen of the total gas volume.
The tests also indicated that in order to prevent the formation of ion precipitates or, when the spray device contains mineralized water, mineral salt precipitates or deposits, the propellent gas mixture preferably contained at least 40% by volume of carbon dioxide of the total gas volume.
The percentage by volume of nitrogen and carbon dioxide of the total gas volume of the propellent gas mixture, preferably, satisfies the relationship (Rel. I):
40/60<%N 2 /%CO 2 <60/40
and
%N 2 +%CO 2 =100 (Rel. I)
More preferably, the percentage by volume of each gas of the total gas volume satisfies the following relationship (Rel. II):
%N 2 =%CO 2 =50 (Rel. II)
but the propellent gas mixture may be composed of 40, 45, 50, 55 or 60% by volume nitrogen with carbon dioxide making up the remainder percentage up to 100%.
The use of carbon dioxide in the propellent gas mixture of the spray device of the present invention can also effect the pH of the liquid or atomizable composition, especially mineral or thermal spring waters, contained in the spray device of the present invention. According to the state of the art, when nitrogen alone is used as the propellent gas, the pH of the contained water at the outlet of the device is between 7 and 8 or neutral to slightly basic. The presence of CO 2 in the propellent gas mixture allows CO 2 to become dissolved in the contained water and as a result, the pH of the water is lowered or acidified such that the pH is closer to that of the skin, which is between 5 and 6. The pH of the water is usually between 6.0 and 6.9, and, preferably between 6.5 and 6.7. As a result, such water is better tolerated by the skin, especially by sensitive to very sensitive skin.
Furthermore, although carbon dioxide is known for its bacteriostatic properties (“The Inhibition by CO 2 of the Growth and Metabolism of Microorganisms”, N. M. Dixon, Journal of Applied Bacteriology, 1989, 67, 109-136), a propellent gas mixture of nitrogen and carbon dioxide used in the spray device of the present invention, preferably wherein the nitrogen and carbon dioxide ratio satisfies Rel. I and, more preferably still, satisfies Rel. II, was not expected to reduce the number of germs present in the medium to be sprayed. By having CO 2 as a component of the propellent gas mixture, it is possible to obtain a medium of mineral and/or thermal spring water with low levels of contamination of less than or equal to 10 germs per 100 ml and, preferably, of less than or equal to 1 germ per 100 ml, in a few days (methods for counting germs followed as given in the European Pharmacopoeia, 2nd Edition, 1983, Vol. I, V.2.1.8) without having to resort to physical decontamination methods.
Different types of means for atomizing or atomizer passages have been tested to optimize the quality of the spray dispersion of a spray device of the present invention as a fine mist. Preferably, an atomizer passage with a nozzle equipped with three vortical channels is used. By using this type of atomizer passage, a propellent gas mixture having a high percentage by volume of carbon dioxide, up to 70% of CO 2 , can be used in the spray device of the present invention to produce of fine spray or mist without the formation of liquid jet at the end spraying.
The valve of the spray device of the present invention provides a satisfactory feed of the contained medium to the atomizer passage without the risk of blockage. Preferably, a valve which can be used head upwards and head downwards is chosen, in order to avoid loss of propellent gas mixture in the event of improper use of the spray canister. More preferably, a valve which can be used exclusively head upwards is envisaged.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 a and 1 b depict a longitudinal cross section of a spray device of the present invention.
FIG. 2 depicts a longitudinal cross section of an atomizer passage with vortical channels.
FIG. 3 depicts a transverse cross section of an atomizer passage with vortical channels.
A personal spray device, represented by FIGS. 1 a and 1 b, comprises a container ( 11 ), contained water ( 10 ) and a propellent gas mixture ( 8 ), a valve and a means for atomizing the water connected to the valve;
the valve is composed of a valve body ( 7 ), a dish ( 12 ), a rod ( 6 ) for actuating the valve and ejecting the water, a seal ( 13 ) and a spring ( 14 );
the container ( 11 ) is surmounted by a removable cap ( 1 );
the means for atomizing is composed of a diptube ( 9 ) attached to the valve body ( 7 ) and a push-button ( 2 );
the push-button comprises a coupling ( 5 ) which fits onto the rod ( 6 ), a distribution channel ( 4 ) and a nozzle ( 3 ).
The nozzle ( 20 ), which terminates in an orifice ( 22 ) and which comprises three vortical channels ( 21 ), is illustrated in FIGS. 2 and 3.
Tests
Spray tests were conducted with spray devices of the present invention pressurized by propellent gas mixtures comprising variable percentages by volume of nitrogen and of carbon dioxide. Unless indicated otherwise, the tests are carried out with a spray device of the present invention equipped with an atomizer passage with three vortical channels of a depth of 0.20 mm and fitted with a flat nozzle. The spray tests were conducted using water from the Vichy basin from a spring called Lucas spring.
All percentages are given as percentages by volume. The initial pressure in the device is 6×10 5 Pas, providing a flow rate of 0.9 g/s for the atomizer passage used. At the end of release, the pressure is 2×10 5 Pas and the flow rate is 0.5 g/s.
Test 1
The proportion of nitrogen and of carbon dioxide in the propellent gas mixture of the spray device of the present invention was varied and the formation or lack of formation of a jet at the end of release was observed. The results are given a value from 0 to 5 where:
0=no jet
1-2=drops
3-4=low-power jet
5=marked jet formation
and are summarized in the table below.
Gas % N 2
100
80
60
50
40
20
0
Mixture % CO 2
0
20
40
50
60
80
100
observations
0
0
0
0
0
3
5
From these tests, it was found that a propellent gas mixture comprising 60% or less of carbon dioxide of the total gas volume did not cause jet formation. 70% carbon dioxide gives useful, but not perfect, results.
Test 2
The effect of carbon dioxide on the pH of the contained mineralized water was evaluated by withdrawing 5 cm 3 of water from the outlet of the spray device with an atomizer passage that allows rapid release. For each gas mixture, three water samples were taken and the pH measured. The measurements were then averaged and are summarized in the table below.
Gas % N 2
100
80
60
50
40
20
0
Mixture % CO 2
0
20
40
50
60
80
100
pH
7.6
6.9
6.7
6.6
6.6
6.6
6.5
These tests indicate that the spray device of the present invention pressurized by a propellant gas mixture containing at least 20%, and preferably 40%, by volume of carbon dioxide provides a spray of water having a pH closer to that of the skin.
Test 3
The formation of a calcium carbonate precipitate was evaluated by measuring, by complexometry (unit of measurement=mg/L), the amount of calcium carbonate dissolved in the water at the nozzle outlet, at the beginning of spraying (A) and at the end of spraying or time release (B).
Gas % N 2
100
80
60
40
0
Mixture % CO 2
0
20
40
60
100
A
53
165
176
170
165
B
—
31
161
163
—
These tests indicate that a gas mixture comprising a higher percentage of nitrogen produces a greater amount of calcium carbonate precipitate. Likewise, when the gas mixture satisfies Rel. (I), no calcium carbonate precipitate is formed.
Test 4
The effect of the gas mixture on bacterial contamination is evaluated. Sterilized physiological water, which would not effect a bacterial population, was contaminated with a given amount of Pseudomonas aeruginosa ATCC19429. The contamination was achieved using calibrated suspensions in order to obtain initial concentrations of (a) 10 5 germs per 100 ml (C 10 5 ) and (b) 10 4 germs per 100 ml (C 10 4 ). These waters were packaged in spray devices according to the invention and pressurized by a gas mixture composed of 50% of nitrogen and of 50% of carbon dioxide (D 1 ). By way of comparison, similarly contaminated waters were packaged (i) in aerosol devices pressurized with nitrogen alone (D 2 ) and, as a control, (ii) in unpressurized aerosol containers (D 3 ). The bacteria content was measured, by filtration, at three different times: at the time of their introduction into the water (T 0 ), after storage for 24 hours (T 24h ) and after storage for seven days (T 7d ) at room temperature (20±2° C.). The results are given as number of germs per 100 ml and summarized in the table below.
T 0
T 24h
T 7d
D1 C 10 4
1.7 × 10 4
3 × 10 2
<5 × 10 −1
D1 C 10 5
8.5 × 10 4
1.8 × 10 2
<5 × 10 −1
D2 C 10 4
2.2 × 10 4
1.3 × 10 4
2.2 × 10 2
D2 C 10 5
1.5 × 10 5
1.3 × 10 5
1 × 10 4
D3 C 10 4
1.7 × 10 4
1.4 × 10 4
3.5 × 10 3
D3 C 10 5
8.5 × 10 4
2.4 × 10 5
4.3 × 10 4
It is found that the device according to the invention pressurized by a gas mixture of nitrogen and carbon dioxide (D 1 ) reduced the number of germs in the water by at least 4 orders of magnitude, whereas the device pressurized with nitrogen only (D 2 ) and the control device (D 3 ) reduced the bacteria content by a single order of magnitude.
Comparable test results indicate that in devices according to the invention, at room temperature (20±2° C.), the microbial population of a mineral or thermal spring water remained stable for at least nine months.
This application is based on French application 95-12788 filed on Oct. 30, 1995 which is incorporated herein in its entirety by reference.
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The invention concerns a new personal spray device pressurized by a gas mixture comprising nitrogen and carbon dioxide for the fine spray dispersion of, for example, liquids or atomizable compositions. The spray device prevents the formation of liquid jet or ion precipitates. Preferably, the spray device contains mineralized waters and controls the pH and the microbial content of the mineralized waters.
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PRIORITY
This application is a divisional application of U.S. patent application Ser. No. 10/641,386, filed Aug. 13, 2003 now U.S. Pat. No. 7,088,434, and is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
The present invention generally relates to gemstone observation, and more particularly to an apparatus and method for isolating and observing the fire of a gemstone.
The quality and value of faceted gemstones are often described in terms of the “four C's”: carat weight, color, clarity and cut. Carat weight is the most objective, because it is measured directly on a balance. Color and clarity are factors for which grading standards have been established by the Gemological Institute of America (GIA), among others.
Cut is much less tractable. Unlike color and clarity, for which a legacy of teaching, trading, and laboratory practice have created a general consensus, there are a number of different grading systems for grading cut of a gemstone. Inherent in most of these systems is the premise that there is one set, or a narrow range, of preferred proportions for some gemstones, and that any deviation from this set of proportions diminishes the appearance or attractiveness of the gemstone. However, under this premise, gemstone cutters typically apply these proportions only to obtain the largest possible size gemstone from an uncut stone, without specific regard to the stone's eventual appearance.
Most gemstones are a convex polyhedron which can be specified according to a number of parameters. FIG. 1 illustrates various parameters that define the proportions of one type of gemstone, a round brilliant cut (RBC) diamond. This type of gemstone can be specified according to eight parameters. Crown angle is the angle, in degrees, between the bezel facets and the girdle plane. Pavilion angle is the angle, in degrees, between the pavilion mains and the girdle plane. Table size represents the width of the table as a percent of the girdle diameter. Culet size represents the width of the culet as a percent of the girdle diameter. Star length is a ratio of the length of the star facets to the distance between the table edge and girdle edge. Lower girdle length represent a ratio of the length of the lower girdle facets to the distance between the center of the culet and the girdle edge. Girdle thickness is preferably measured between bezel and pavilion main facets, and is expressed as a percentage of girdle diameter. Finally, girdle facet number is the total number of facets on the girdle. Given a number of gemstones of the same color, weight and clarity, varying any of the above parameters produce different appearances.
Other than color, weight, and clarity, gemstone appearance has historically been described chiefly in terms of three aspects: brilliance, scintillation, and fire. While interrelated, these aspects can be characterized independently. Brilliance, or brightness, generally refers to the level of white light returned through the crown of a gemstone to an observer overhead. Scintillation refers to flashes of light reflected from the crown of a gemstone, particularly as the gemstone is rotated or tilted. Fire is the result of the light-dispersive quality of a gemstone, and refers to visible rays or flares of colored light returned by the gemstone.
It is believed that with knowledge about how cut relates to each of these aspects, alone or in combination, then perhaps improved cut parameters can be established to yield more attractive, and thus more valuable, gemstones. Unfortunately, each aspect above represents a complex concept without a precise mathematical definition, making it very difficult to measure on actual gemstones.
Models have been developed for some aspects, however. For example, GIA developed a mathematical model for brilliance, discussed in Modeling the Appearance of the Round Brilliant Cut Diamond: An Analysis of Brilliance , by Hemphill et al., Gems & Gemology, Vol. 34, No. 3, pp. 158-183, the contents of which are incorporated by reference herein in their entirety and for all purposes. GIA's brilliance model uses a simulated round brilliant cut (RBC) diamond and a modeled light source of diffused, hemispherical white light shining on the crown. Then, researchers used computer simulation techniques to examine mathematically how millions of rays of light from the virtual light source interact with the virtual gemstone. This model generated images and a numerical measurement of the optical efficiencies of the gemstone called weighted light return (WLR). The WLR is a weighted sum of the amount of light returned through the crown of the virtual diamond to all positions of observation above the girdle. Thus, WLR approximates overall brilliance in an environment with even diffused lighting and no objects, such as an observer, in the environment.
Similar assumptions and qualifications were used in developing a metric for fire. See Modeling the Appearance of the Round Brilliant Cut Diamond: An Analysis of Fire, and More About Brilliance , Gems & Gemology, Vol. 37, No. 3, pp. 174-197, the contents of which are also incorporated by reference herein for all purposes. While brilliance is emphasized with diffuse illumination found in most common lighting environments, fire is best observed using a highly directed, narrow beam of light, referred to herein as “spot lighting.” Accordingly, GIA chose to model the directed lighting as a bright point source of illumination located very far from the gemstone, i.e. at infinite distance, centered over and directed toward the gemstone's table. Under these conditions, the unpolarized light rays entering the crown facets are parallel to one another and perpendicular to the table, to illuminate the entire crown. The metric derived—dispersed colored light return, or DCLR—describes the potential of an RBC gemstone with certain proportions to display dispersed colored light when viewed face-up.
Fire is the most difficult aspect of a gemstone to observe. Fire is often mixed with scintillation, the white light flashes that obscure the rays of colored light. Further, white light in general, either from the lighting environment itself or returned from the gemstone as brilliance, can overwhelm and suppress the visible effects of fire.
A particular type of directed light source, for example one which approximates the GIA modeled light source, can isolate or enhance observable fire. However, several problems exist with finding and using such a source. Commercially-available narrow beam spot lights are not sufficiently directed, and allow too much white light from too many angles to reach a gemstone being observed, obscuring the fire. On the other hand, some highly directed light sources, such as lasers or light emitting diodes, radiate at too little of the visible spectrum for viewing the full range fire-based color separation. What is needed is a apparatus and method by which a white light source is channeled directly to a gemstone, in order to better isolate, observe and measure fire.
SUMMARY OF THE INVENTION
The present invention is directed toward providing a light source which isolates and accentuates a gemstone's fire. This invention overcomes the limitations of conventional lighting schemes by providing directed, spot lighting having a full spectrum of visible radiant energy, which allows an observer to view the full extent of dispersion of light within a gemstone into separate wavelengths.
In one exemplary embodiment of the invention, an apparatus for providing a spot lighting source for observing fire of a gemstone includes a tube. The tube has an inlet for receiving a portion of light from a light source, and an outlet for providing spot lighting from the received portion of light channeled through the tube. Accordingly, the spot lighting carries approximately the same spectrum as the original light source. The apparatus further includes a mask, coupled with the tube to shield the outlet from other portions of light from the light source.
The another embodiment, a method of observing fire from a gemstone includes the steps of receiving a portion light from a visible or white light source at an inlet of a tube, and channeling the received portion of light through the tube. The method further includes the step of outputting the channeled light as spot lighting from an outlet of the tube. In the embodiment, the light channeled through the tube is directed but not diminished, so that the spot lighting has approximately the same spectrum as the light from the light source.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates various proportions of one type of gemstone.
FIG. 2 is a perspective view of a system for providing a spot light source for observing fire of a gemstone.
FIG. 3 is a cross-sectional view of a system for providing a spot light source from a portion of light from a light source to a gemstone.
FIG. 4 is a cross-sectional view of a system, which includes a calorimeter, for providing a spot light source from a portion of light from a light source to a gemstone.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
This invention relates to an apparatus and method for isolating colored light returned from within a gemstone. More specifically, this invention provides an apparatus and method for providing directed or spot lighting to a gemstone for observing the full effects of dispersion of a white light source by the gemstone into individual rays of colored light, known as “fire.” In a particular embodiment, this invention uses a conventional daylight-approximating light source and provides narrow spot lighting having the same or near-same spectral characteristics as the light source. Thus, this invention avoids the need for lenses, internal reflective layers for light propagation, or other mechanisms that modify or alter a light source.
FIG. 2 shows an embodiment of an apparatus 200 for providing spot lighting to a gemstone. The apparatus 200 is generally adapted for use with any light source, but is preferably employed in combination with a daylight-approximating light source. As used herein, “daylight approximating” refers to a light source that approximates diffused, white light, or in other words, light which radiates all or nearly all of the visible electromagnetic radiation spectrum. The preferred operating environment for the apparatus 200 is dark other than the light source described herein.
The apparatus includes a tube 202 . The tube includes an inlet 204 and an outlet 206 on an opposite end from the inlet 204 . The inlet 204 is configured to receive a portion of light 205 from a light source 209 , which received light is channeled through the tube 202 toward the outlet 206 . The portion of light 205 received at the inlet 204 can represent, for example, 1 to 5 degrees in arc-length of a cross-section of the radiation profile of light 205 emitted from the light source 209 . The apparatus 202 also includes a mask 208 coupled to the tube 202 to shield other portions of the light 205 from the tube 202 or outlet 206 .
The tube 202 is preferably straight, elongate and hollow. In an alternative embodiment, the tube 202 may have a squared or angled cross-section along its circumference. The tube 202 is preferably 0.5 to 6 feet in length, and in a specific embodiment is 2 to 3 feet in length. The tube 202 may be any length, however, that sufficiently channels light without excessive loss. The interior diameter of the tube 202 is preferably between 0.1 and 1 inches. In one exemplary embodiment, the tube 202 has an inner diameter of approximately 0.5 inches. In yet another embodiment, the apparatus 200 can include, inside tube 202 or near the inlet 204 or outlet 206 , an aperture or an iris that is adjustably sized for different-sized gemstones.
The tube 202 can be formed of metal, plastic or glass, or any other suitably rigid material, such as ceramic or polypropylene. The tube 202 is formed of a material having an inner polished surface that channels light with a particular amount of reflection, absorption, or dispersion, and preferably minimizing each. In one embodiment, the tube 202 includes an interior coating or layer that is selected for its particular light propagation qualities.
In a preferred embodiment, the apparatus 200 is used in combination with a light source 209 that is a daylight-approximating halogen lamp, such as an MR16 halogen display lamp (12 Volt, 50 Watt, 4700K color temperature and 10 degree narrow spot) manufactured by Solux™. The light source 209 can include a filter. While white light is preferred, it should be understood that other types of light-producing devices may suitably be used as the light source 209 .
The mask 208 is preferably coupled to the tube 202 at or near the inlet 204 , but is generally positioned between the inlet 204 and the outlet 206 . In one embodiment of the invention, the mask 208 is shaped to correspond to the illumination profile or pattern of the light source 209 . For example, the mask 208 can be round and rigid like a plate. However, it should be readily apparent to one skilled in the art that the mask 208 can have any shape, and a wide range of sizes and rigidity. The mask 208 is also preferably planar and thin, but can have any thickness. The mask 208 can be formed of any rigid or semi-rigid, sufficiently opaque material or structure which can block the passage of light radiation emitted from the light source 209 or other extraneous sources of light in the lighting environment. In this regard, the exterior surface of the mask 208 and the outer surface of the tube 202 can be dark and non-reflective in a practical implementation to reduce the amount of potential light reflections. Additionally, the mask 208 should be resistant to any thermal radiation generated by the light source 209 .
The apparatus 200 can also include a mounting mechanism 210 for mounting the tube 202 to a fixed object, and for positioning the tube 202 at a particular orientation or location. For instance, the mounting mechanism 210 can have one end configured to attach to a wall, or to mount to a table or other flat surface. The other end of the mounting mechanism 210 can be coupled to the tube 202 . The mounting mechanism 210 is used to align the inlet 204 of the tube 202 with the light source 209 , and/or align and adjust the height or position of the outlet 206 relative to a gemstone being observed. In another embodiment, the tube 202 is held stationary by the mounting mechanism 210 , and a gemstone being observed is positioned a suitable distance away from the outlet 206 of the tube. In accordance with one practical embodiment, the gemstone is held at least three feet away from the outlet 206 .
FIG. 3 is a cross-sectional view of an apparatus 201 for providing spot lighting, employed in a system 300 for observing fire of a gemstone 100 . Along with the apparatus 201 , the system 300 also includes a stage 110 for supporting one or more gemstones 100 being observed. The stage 110 is shown supporting only one gemstone for simplicity, however the stage 110 may be configured to support two or more gemstones. The stage 110 is preferably non-reflective. In one embodiment, the stage 110 is configured for supporting the gemstone 100 in a table-up position to allow for the maximum amount of dispersed colored light to be returned through the crown.
When gemstone 100 is near, i.e. directly under, the outlet 306 of the tube 302 , and the light source 309 is near, i.e. directly over, the inlet 304 of the tube 302 , a portion 303 of the light 305 emitted from the light source 309 is channeled through the interior 312 of the tube 302 in the direction indicated. The interior 312 is generally defined by a the cross-sectional inner area of the tube 302 , summed along the length of the tube. The portion 303 of the light 305 generally corresponds to the area of the inlet 304 , and includes visible radiation from any angle. The portion 303 of light 305 that is received at the inlet is channeled to the outlet 306 , where it is provided as a directed, spot lighting 307 . Importantly, very little to none of the visible spectrum of the received portion 303 of light is lost in the spot lighting 307 .
A mask 308 shields an area around the gemstone from the light 305 of the light source 309 . The mask 308 may also be configured to shield the area from other light of the lighting environment, such as indirect sunlight, other overhead lights, etc. The mask 308 therefore prevents dispersed white light from reaching the gemstone 100 and obscuring the effects of fire from the spot lighting 307 .
In one embodiment, the apparatus 201 is stationary, and the stage 110 and light source 309 are moved to their positions. In an alternative embodiment, the stage 110 and light source 309 are stationary, and a mounting mechanism 310 is configured for allowing the tube 302 to be placed into position. In still yet another embodiment, the light source 309 , the apparatus 201 and the stage 110 are all movable.
The present invention may be specifically embodied as a tool to train observers to look for the specific colored flashes or rays of light that emanate from a gemstone as a result of its dispersive qualities. As illustrated in FIG. 4 , this invention may also be embodied as a system 400 for measuring or characterizing the effects of fire. In a measuring system, a measuring device such as a calorimeter 402 may be positioned near the gemstone to determine and/or quantify the specific colors of the gemstone's fire. Alternatively, a photodetector or similar instrument may be used to determine a level of colored light returned by a gemstone, or compared with the spot lighting supplied by the apparatus 100 . In this alternative embodiment, a filter or group of filters associated with the photodetector may be used to isolate specific wavelengths of visible colored light. A measuring system can also include a computer for processing measurement data, and a database for storing the results of the processing. Further, the database can be compiled as a reference, which can be accessed for later measurements and/or comparisons.
By isolating and observing the effects of fire of many gemstones, it can be determined how a particular cut relates to this aspect of a gemstone's appearance, assuming other factors such as color, clarity and weight are the same. Thus, this invention provides useful information for establishing a set of preferred proportions for gemstones.
While various embodiments of the invention are described above, it should be understood that they are presented for example only, and not as limitations to the following claims. Accordingly, the scope and breadth of the present invention should only be defined in accordance with the following claims and their equivalents.
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An apparatus, system and method for providing spot lighting for observing a gemstone is presented. In particular, the spot lighting provided by the invention allows for observing of the fire of a gemstone, i.e. the visible effects of light dispersion into separate colors. The apparatus includes a tube for receiving a portion of a multi-spectral light source, and a mask coupled to the tube for blocking other portions of the light source. By selecting the proper tube dimensions and aligning the tube with both the light source at an inlet and a gemstone at an outlet, the spot lighting source provides direct lighting for isolating and accentuating the effects of fire.
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As used in the specification and claims, the term "nylon 66" shall mean those synthetic linear polyamides containing in the polymer molecule at least 85% by weight of recurring structural units of the formula ##STR1##
Historically, certain nylon 66 apparel yarns were spun at low speeds of up to about 1400 meters per minute and packaged. The spun yarns were then drawn on a second machine and packaged again. The drawn yarn was then false-twist textured at slow speeds of the order of 55-230 meters per minute by the pin-twist method, yielding a very high quality stretch yarn suitable for stretch garments such as leotards. An exemplary false-twisting element for the pin-twist texturing process is disclosed in Raschle U.S. Pat. No. 3,475,895.
More recently, various other types of false-twisting apparatus have come into commercial use, and are collectively referred to as "friction-twist". Some of the most widely used of these include a disc aggregate of the general type illustrated in Yu U.S. Pat. Nos. 3,973,383, Fishback 4,012,896 or Schuster 3,885,378. Friction-twisting permits considerably higher texturing speeds than pin-twisting, with yarn speeds currently at about 700-900 mpm. Such high texturing speeds are more economical than those attained by the pin-twist process.
Along with the shift to friction-twisting has come a shift to partially-oriented nylon 66 (PON) yarns as the feeder yarns for the friction-twist process. In the conventional PON spinning process, the winding speed is merely increased from the previous standard of about 900-1500 meters per minute to speeds generally in the 2750-4000 meters per minute range, resulting in a PON yarn. PON yarn performs better in the high speed friction-twist texturing process than either the earlier drawn yarn or the low-speed spun yarn mentioned above. However, heretofore yarns textured by the friction-twist process were of distinctly lower quality in terms of crimp development than yarns textured by the pin-twist process. The apparel nylon 66 false-twist textured yarn market is accordingly in essentially two distinct segments: the older, expensive, high quality pin-twist yarns, and the newer, less costly, lower quality friction-twist yarns.
PON feeder yarns for false-twist texturing have had RV's in the range from the middle or upper thirties to the low forties, as indicated by U.S. Pat. No. 3,994,121. Such yarns have more than adequate tenacity for conventional apparel end uses. With conventional nylon 66 polymerization techniques, increasing the polymer RV is expensive and leads to increased rates of gel formation, with consequent shortening of spinning pack (filter) life. High RV polymer is therefore ordinarily not used unless required for some special purpose, such as when high yarn tenacity is required.
It has recently been discovered that high RV PON feeder yarns permit manufacture of friction-twist yarns having increased crimp development, in some cases comparable to that of pin-twist yarns. This increased crimp development provides a substantial increase in fabric covering power as compared to fabrics made from friction-twist yarns made from PON feeder yarns as disclosed by Adams U.S. Pat. No. 3,994,121. Accordingly, less textured yarn is required to provide a fabric of equivalent covering power. Increased productivity in spinning and texturing is also provided by high RV PON yarns.
According to the present invention, a further and substantial improvement in the art is provided by a novel PON feeder yarn, permitting formation of a friction-twist textured yarn having in some cases markedly higher crimp development than even some pin-twist yarns. This permits either or both of increased stretching capability in a fabric of equivalent covering power.
The yarns of the invention are, broadly, false-twist texturing feed yarns spun at high speeds and characterized by a sheath-core conjugate structure, with the sheaths formed from nylon 66 polymer containing a higher amount of branching agent than the polymer forming the cores. The mechanism or precise reason for the improved results of the present invention are not entirely understood.
According to a first principal aspect of the invention there is provided an apparel yarn having an elongation between 45% and 150% and comprising a filament spun at a spinning speed of at leat 2000 MPM, the filament having a nylon 66 sheath component surrounding a core component, the sheath component containing a larger amount of branching agent than the core component.
Accordingly to a second principal aspect of the invention there is provided a process for spinning a sheath-core filament, comprising generating a molten stream comprising a nylon 66 sheath component containing a given quantity of branching agent and core component containing a lower quantity of branching agent (preferably none) than the sheath component, extruding the stream through a spinneret capillary, quenching the stream into a filament, and withdrawing the filament at a spinning speed of at least 2000 MPM.
According to a third principal aspect of the invention there is provided a process for producing a textured yarn, comprising friction-twist texturing a yarn having an elongation between 45% and 150%, the yarn comprising a filament spun at a spinning speed of at least 2000 MPM, the filament having a nylon 66 sheath component surrounding a core component, the sheath component containing a larger effective amount of branching agent than the core component.
According to any of the above principal aspects of the invention, the core component is also preferably nylon 66, and if the yarn is to be used as a feed yarn for false-twist texturing, the branching agent preferably constitutes between 0.01 and 1 (optimally between 0.05 and 0.15) mole percent of the sheath component. The sheath component preferably comprises less than 50% (optimally between 10% and 40%) by weight of the filament. For best results the spinning speed is selected such that the yarn has an elongation lower than 100%, with optimum results achieved when the elongation is between 60% and 90%. The preferred branching agents are trifunctional amines, such as TAN or BHMT, or trifunctional acids, such as trimesic acid.
Other aspects of the invention will in part appear hereinafter and will in part be obvious from the following detailed description taken together with the accompanying drawing, wherein:
FIG. 1 is a schematic front elevation of an exemplary apparatus for spinning the yarns of the invention; and
FIG. 2 is a cross-section of an exemplary filament according to the invention.
As shown in FIG. 1, molten polymer streams 20 are extruded through capillaries in spinneret 22 downwardly into quench zone 24 supplied with transversely directed quenching air at room temperature. Streams 20 solidify into filaments 26 at some distance below the spinneret within the quench zone. Filaments 26 are converged to form yarn 28 and pass through interfloor conditioner tube 30. A conventional spin-finish is applied to yarn 28 by finish roll 32. Yarn 28 next passes in partial wraps about godets 34 and 36 and is wound on package 38. The filaments may be entangled as desired, as by pneumatic tangle chamber 40.
Ordinarilly, godets 34 and 36 perform the functions of withdrawing filaments 26 from streams 20 at a spinning speed determined by the peripheral speed of godet 34, and of reducing the tension in yard 28 from the rather high level just prior to godet 34 to an acceptable level for winding onto package 38. Winding tensions within the range of 0.03 to 0.25 grams per denier are preferred, with tensions of about 0.1 grams per denier being particularly preferred. Godets 34 and 36 may be dispensed with if the yarn winding tension immediately prior to the winder in the absence of the godets is within the yarn tension ranges indicated in this paragraph. "Winding tension" as used herein means the yarn tension as measured just prior to the yarn traversing and winding mechanism. Some commercially available winders include an auxiliary roll designed to both assist in yarn traversing and to permit reducing the yarn tension as the yarn is wound onto the bobbin or package. Such winders may be of assistance when using the upper portions of the yarn tension ranges indicated in this paragraph.
DESCRIPTION OF THE PRIOR ART
Example 1
This is an example within the range of present conventional practice. Nylon 66 polymer having an RV of 39 is extruded through a conventional spinning pack and spinneret at a melt temperature of 385° C. Spinneret 22 contains 34 capillaries having lengths of 0.012" (0.3 mm.) and diameters of 0.009" (0.229 mm.) Quench zone 24 is 35 inches in height, and is supplied with 20° C. quench air having an average horizontal velocity of 1 foot (30.5 cm.) per second. Filaments 26 are converged into yarn 28 approximately 36 inches (91.4 cm.) below the spinneret. Conditioner tube 30 is 72 inches (183 cm.) long and is of the type disclosed in Koschinek U.S. Pat. No. 4,181,697, i.e., a steamless tube heated to 120° C. through which yarn 28 passes. The speed of godets 34 and 36 are 4100 meters per minute and 4140 meters per minute, respectively, to prevent the yarn from wrapping on godet 36. The polymer metering rate is selected such that the yarn wound has a denier of 89. The winder used is the Toray 601, and the winder speed is adjusted to provide a winding tension of 0.1 grams per denier. The yarn has an elongation-to-break of 68%, and an RV of 41.
The spun yarn is then simultaneously drawn and friction-twist textured on a Barmag FK6-L900 texturing machine using a 21/2 meter primary heater and a Barmag disc-aggregate with Kyocera ceramic discs in a draw zone between a feed and a draw or mid roll. The heater temperature is 225° C., and the ratio of the peripheral speed of the discs to draw roll speed (the D/Y ratio is 1.95. The draw roll speed is set at 750 meters per minute, and the feed roll speed is adjusted to some lower speed to control the draw ratio and hence the draw-texturing tension (the yarn tension between the exit of the heater and the aggregate). In order to maximize the crimp development, the draw ratio is changed by adjustment of the feed roll speed so that the draw-texturing tension is high enough for stability in the false twist zone and yet low enough that the filaments are not broken, this being the operable texturing tension range. Within the operable tension range, the "maximum texturing tension" is defined as the tension producing the maximum initial crimp development without an unacceptable level of broken filaments (frays). More than 10 broken filaments per kilogram are unacceptable in commercial use.
With the Example 1 yarn, the operable texturing tension range is quite narrow when draw-texturing at 750 meters per minute. The maximum texturing tension is found to be about 0.43 grams per draw roll denier, and the aged crimp development is about 15%. The draw roll denier is defined as the spun yarn denier divided by the mechanical draw ratio provided by the different surface speeds of the feed roll feeding the yarn to the heater and of the draw or mid roll just downstream of the false-twist device. When the texturing tension is more than 0.45 grams per draw roll denier, an unacceptable level of broken filaments is produced. The textured yarn has a nominal denier of 70.
If the broken filaments are ignored and texturing tension is increased beyond 0.43 grams per draw roll denier, crimp development increases somewhat at a tension of about 0.44 grams per draw roll denier. However such yarns are not commercially acceptable due to the number of broken filaments (frays). With the spun yarn of this example, an attempt to increase crimp development by increase in heater temperature much above 225° C. also leads to an unacceptable level of broken filaments.
Example 2
This is an example of high RV PON yarn. The spinning process of the first paragraph of Example 1 is repeated, except the polymer is selected and dried so that the yarn RV is about 70. The PON yarn denier is 100, and the yarn has an elongation-to-break (elongation) of 88%. When the spun yarn of this paragraph is draw-textured (245° C. heater) at its maximum texturing tension, the textured yarn has an aged crimp development of about 18-19%, which is comparable to the levels achieved by the pin-twist process. Finished fabrics formed from the textured yarn of this example have greater covering power than similar fabrics formed from the textured yarn of Example 1.
Further increases in texturing tension do not appreciably affect the crimp development, but merely result in broken filaments or yarn breaks.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 2 illustrates the preferred sheath-core filament according to the invention, with sheath 40 surrounding core 42. Spinneret pack designs for forming such sheath-core filaments are well known in the art. According to the invention, sheath 40 is nylon 66 containing a branching agent as more fully disclosed below.
Example 3
This is an example according to the invention. The apparatus described in Example 1 is used except the spinneret pack used in Examples 1 and 2 above is replaced by a spinneret pack designed to produce 34 sheath-core filaments. A first batch of nylon 66 polymer containing 0.34 mol % acetic acid and 0.125 mol % TAN is dried to produce nominal 49 yarn RV, and a second batch of conventional nylon 66 polymer containing 0.34 mol % acetic acid and no chain branching agent is dried to produce nominal 37 yarn RV. The polymers are spun under the conditions set forth in Example 1 above as sheath-core filaments with the polymer containing the TAN forming the sheaths and the second polymer forming the cores. The sheath-core volumetric ratio are 2 to 3. That is, the sheaths constitute 40% of the volume of the filaments, the remaining 60% being the core component. The PON yarn has a denier of 107 and an elongation of 86%, to provide a textured denier of 70.
When the PON yarn is drawtextured by the friction twist method at its maximum texturing tension (225° C. heater), the textured yarn has an aged crimp development of 18.9%. This is substantially greater than the crimp development levels achieved by friction twist texturing of conventional 40 RV PON, and is comparable to the high RV yarn of Example 2 herein.
Example 3 is repeated except the first polymer is further dried to produce nominal 60 RV. The resulting textured yarn has an aged crimp development well above 20%, clearly superior to the Example 2 yarn.
The increased crimp development provides for greater stretch and covering power in fabrics made from the textured yarn of the invention.
The improved results according to the invention are not achieved unless the spinning speed is at least 2200 MPM, with speeds above 3000 MPM being preferred. Spinning speeds above 3400 MPM are particularly advantageous.
While the invention is above exemplified using TAN, numerous other branching agents may be used. BHMT is another example of such an agent with functional groups reactive with the carboxyl groups in nylon 66 polymer, while trimesic acid is an example of an agent with functional groups reactive with the amine groups in nylon 66 polymer. Any necessary adjustment of the amount of branching agent can readily be done by trial and error. Suitable branching agents generally contain three or more functional groups reactive with amine or carboxylic and groups under the conditions used for polymerization the polymer, and generally increase the polymer molecular weight. Alpha-amino-epsilon-caprolactam is noted a another suitable material which has the requisite number of functional groups, some of which react with amines and some which react with carboxyl groups. If the branching agent contains more than three such functional groups, it may be necessary to reduce the level of branching agent significantly below those indicated above as preferred with TAN.
TEST METHODS AND DEFINITIONS
"TAN" is the trifunctional branching agent 4(aminomethyl)-1,8-diaminooctane having the following structural formula: ##STR2##
"BHMT" is bis-hexamethylene triamine.
All yarn packages to be tested are conditioned at 21 degrees C. and 65% relative humidity for one day prior to testing.
The yarn elongation-to-break (commonly referred to as "elongation") is measured one week after spinning. Fifty yards of yarn are stripped from the bobbin and discarded. Elongation-to-break is determined using an Instron tensile testing instrument. The gage length (initial length) of yarn sample between clamps on the instrument) is 25 cm., and the crosshead speed is 30 cm. per minute. The yarn is extended until it breaks. Elongation-to-break is defined as the increase in sample length at the time of maximum load or force (stress) applied, expressed as a percentage of the original gage length (25 cm.).
Crimp development is measured as follows. Yarn is wound at a positive tension less than 2 grams on a Suter denier reel or equivalent to provide a 11/8 meter circumference skein. The number of reel revolutions is determined by 2840/yarn denier, to the nearest revolution. This provides a skein of approximately 5680 skein denier and an initial skein length of 9/16 meter. A 14.2 gram weight or load is suspended from the skein, and the loaded skein is placed in a forced-air oven maintained at 180° C. for 5 minutes. The skein is then removed from the oven and conditioned for 1 minute at room temperature with the 14.2 gram weight still suspended from the skein, at which time the skein length L2 is measured to the nearest 0.1 cm. The 14.2 gram weight is then replaced with a 650 gram weight. Thirty seconds after the 650 gram weight is applied to the skein, the skein length L3 is measured to the nearest 0.1 cm. Percentage crimp development is defined as L3-L2/L3×100. Crimp development decreases with time as the textured yarn ages on the bobbin, rapidly for the first hours and days, then more slowly. When "initial crimp development" is specified herein, the measurement is made about one day after texturing.
Relative viscosity (RV) is determined by ASTM D789-81, using 90% formic acid.
Broken filaments are determined visually, by counting the number of broken filaments on the exposed surfaces of the packages.
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In a partially oriented nylon feed yarn for drawtexturing, the filaments have sheaths containing a branching agent while the cores do not. Exceptional crimp development is achieved in the resulting textured yarn.
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This application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 61/921,228 filed Dec. 27, 2013, which is incorporated by reference in its entirety.
FIELD OF INVENTION
This invention relates to securing openings, and in particular to systems, devices, apparatus, kits and methods of attaching rigid panels, such as transparent plastic panels over window and door openings of vacant and/or damaged buildings and houses, with connecting block adapters attached to the lower corners of the panels by fasteners, and security bars slid into holes on the adapters with ends that abut against portions of the adjacent frames and casings about the openings.
BACKGROUND AND PRIOR ART
In the last decade, there has been an increase in the number of buildings and houses, where the property owner has left the property due to property owners defaulting on loans that are higher than the actual value of the property, and/or leaving properties that have been damaged by storms, or vandalism, and the like. As such, lenders and mortgage companies have the need for property preservation to secure the empty and vacant buildings and houses.
Vacant structures often have broken windows, which are an attractive nuisance for vagrants, criminals and children that can result in thefts and destruction of interiors of the structures, as well as be unsafe and dangerous to persons entering the property
Boarding up openings with plywood and traditional shutters, can be both expensive, and time consuming. Additionally, using fasteners, such as nails, screws, bolts to directly attach boards and shutters can cause further damage to the property.
Additionally, boards and shutters are generally opaque and do not allow light therethrough. As such, the interiors of the structures are darkened which can result in further problems by having darkened interiors at all times.
Furthermore, the use of boards and shutters gives an immediate indication to a passerby that the property is vacant, which further attracts vagrants, criminals and children that can cause undesirable problems such as damage to the property.
Still furthermore, the appearance of boarded up windows and opaque shutters are both unsightly and can lower the property values for the buildings and houses.
As such, there exists a need to allow for simple and easy securing of the buildings and houses for property preservation. Additionally, there is a need for securing openings to the property with panels that are transparent and let light into the structures, and can give the appearance of the property not being vacant.
Thus, the need exists for solutions to the above problems with the prior art.
SUMMARY OF THE INVENTION
A primary objective of the present invention is to provide systems, devices, apparatus, kits and methods of attaching transparent plastic panels over door and window openings of vacant buildings and houses, with connecting block adapters attached to the lower corners of the panels by fasteners, and security bars slid into holes on the adapters with ends that abut against portions of the adjacent frames and casings about the openings.
A secondary objective of the present invention is to provide systems, devices, apparatus, kits and methods for securing openings such as windows and doors of vacant and/or damaged buildings and houses that can be easily attached without causing permanent damage to the openings.
A third objective of the present invention is to provide systems, devices, apparatus, kits and methods for securing openings such as windows and doors of vacant and/or damaged buildings and houses that is easily and inexpensively attached to the openings.
A fourth objective of the present invention is to provide systems, devices, apparatus, kits and methods for securing openings such as windows and doors of vacant and/or damaged buildings and housings, using transparent panels to allow light inside.
A fifth objective of the present invention is to provide systems, devices, apparatus, kits and methods for securing openings such as windows and doors of vacant and/or damaged buildings and houses, that gives the appearance of the openings not being vacant nor boarded up or closed with shutters.
A sixth objective of the present invention is to provide systems, devices, apparatus, kits and methods for securing openings such as windows and doors of vacant and/or damaged buildings and houses, that is not unsightly and does not result in lowering of the property value of the buildings and houses.
A securing system for covering openings to buildings and housings, can include a rigid plastic panel sized to cover at least one exterior opening through a frame casing to a structure, at least one pair of securing block adapters, each being sized to overlap both left and right corners of the transparent plastic panel and portions of the frame casing, fasteners for attaching the transparent plastic panel to portions of the block adapters, and a securing bar attached to other portions of the block adapters, so that the transparent plastic panel is on an exterior side of the structure opening and the block adapter with securing bar are on an interior side of the structure opening.
The panel can be selected from at least one of a solid acrylic material, a solid transparent resinous material, or a transparent polycarbonate material.
Each of the block adapters each can include a first opening for a fastener, and a second opening perpendicular to the fastener opening for allowing a portion of the securing bar to be inserted therein.
The block adapters can include materials selected from wood, stainless steel, galvanized metal and aluminum. The block adapters can be formed from rigid plastic material identical to the rigid plastic panel.
The structure opening can include a window having glass attached to the frame casing.
The fasteners can include bolts and nuts, and/or screws and nuts.
A method of securing openings on structures, can include the steps of sizing a rigid plastic panel to fit over an opening to a structure, providing at least a pair of securing block adapters, providing at least one securing bar, positioning the rigid transparent plastic panel over the exterior of the structure opening, positioning one of the securing block adapters to overlap over a lower left corner portion of an interior to the structure opening and over a portion of a lower left corner of a frame casing about the structure opening, positioning another one of the block adapters to overlap over a lower right corner portion of an interior to the structure opening and over a portion of a lower right corner of a frame casing about the structure opening, attaching the block adapters to the sized rigid plastic panel with fasteners, and sliding the securing bar through openings in the block adapters so that ends of the block adapters abut against portions of the frame casing on both sides of the structure opening, wherein the structure opening is securely covered and protected by the rigid transparent plastic panel.
The plastic panel can be selected from a solid transparent acrylic material, a solid transparent resinous material, or a transparent polycarbonate material.
Each of the block adapters can include a first through-hole for the fastener, and a second through-hole perpendicular to the first through-hole for the securing bar.
The block adapters can include materials selected from wood, stainless steel, galvanized metal and aluminum.
The block adapters can be formed from rigid plastic material identical to the rigid plastic panel.
The structure opening can include a window having glass in the frame casing.
The fasteners can include bolts and nuts and/or screws and nuts.
A protection kit for covering openings to buildings and housings, can include a rigid plastic panel sized to cover at least one exterior opening through a frame casing to a structure, at least one pair of securing block adapters, each being sized to overlap both left and right corners of the plastic panel and portions of the frame casing, fasteners for attaching the transparent plastic panel to portions of the block adapters, and a securing bar attached to other portions of the block adapters, so that the transparent plastic panel is on an exterior side of the structure opening and the block adapter with securing bar are on an interior side of the structure opening.
Each of the block adapters can include a first opening for a fastener, and a second opening perpendicular to the fastener opening for allowing a portion of the securing bar to be inserted therein.
Further objects and advantages of this invention will be apparent from the following detailed description of the presently preferred embodiments which are illustrated schematically in the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is an exploded view of the novel block adapters, with fasteners and securing bar and plastic sheet for use with protecting window openings to a building or house.
FIG. 2A is an enlarged upper front left perspective view of a novel block adapter of FIG. 1 .
FIG. 2B is an upper front right perspective view of the block adapter of FIG. 2A .
FIG. 2C is another left front perspective view of the block adapter of FIG. 2A .
FIG. 2D is a front view of the block adapter of FIG. 2A .
FIG. 3 is a partial perspective interior view of a window opening to a building or house with the novel block adapters and securing bar and fasteners of FIG. 1 on the inside of the opening, with exterior plastic panel on outside of window opening.
FIG. 4 is an interior view of the window opening with block adapters, securing bar and fasteners on the window opening of FIG. 3 .
FIG. 5 is an exterior view of the window opening with block adapters, securing bar and fasteners on the window opening of FIG. 3 .
FIG. 6 is a flowchart of the installation steps to install a transparent plastic panel over an opening shown in FIGS. 3-5 , using the connecting block adapters.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before explaining the disclosed embodiments of the present invention in detail it is to be understood that the invention is not limited in its applications to the details of the particular arrangements shown since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.
In the Summary above and in the Detailed Description of Preferred Embodiments and in the accompanying drawings, reference is made to particular features (including method steps) of the invention. It is to be understood that the disclosure of the invention in this specification includes all possible combinations of such particular features. For example, where a particular feature is disclosed in the context of a particular aspect or embodiment of the invention, that feature can also be used, to the extent possible, in combination with and/or in the context of other particular aspects and embodiments of the invention, and in the invention generally.
In this section, some embodiments of the invention will be described more fully 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 convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout, and prime notation is used to indicate similar elements in alternative embodiments.
The components will now be described.
10 fasteners such as carriage bolt(s) and screws 12 fastener head(s) 14 . threads 16 washer(s) 18 nut(s) 20 bar/pipe 22 caps 30 plastic sheet/panel 100 block adapter(s) 110 flat front face 112 convex curved top 115 fastener through-hole 118 convex curved bottom 120 flat rear face 130 left flat side 135 securing bar through-hole 140 right flat side 200 assembled view 210 interior window frame/casing 220 exterior window opening 225 . existing glass in window opening
FIG. 1 is an exploded view of the novel block adapters 100 , with fasteners 10 , and securing bar 20 and plastic sheet/panel 30 for use with protecting window openings to a building or house. FIG. 2A is an enlarged upper front left perspective view of a novel block adapter 100 of FIG. 1 . FIG. 2B is an upper front right perspective view of the block adapter 100 of FIG. 2A . FIG. 2C is another left front perspective view of the block adapter 100 of FIG. 2A . FIG. 2D is a front view of the block adapter 100 of FIG. 2A .
Referring to FIGS. 1-2D , the invention can include a pair of fasteners 10 , bar/pipe 20 , a pair of block adapters 100 , and a plastic sheet/panel 30 . The fasteners 10 can include carriage type bolts, with enlarged heads 12 , threaded sides 14 , washers 16 and nuts 18 . Other types of fasteners, such as screws and the like, can also be used.
The securing bar 20 can an elongated metal pipe, and the like, that can be solid or hollow. Additionally, a solid plastic rod/bar can be used as well as PVC, and the like.
The plastic sheet panel 30 can be formed from polycarbonate material, and be sized to cover the opening to a window. The rigid transparent plastic panels 30 , that can be used with the invention, include but are not limited to a rigid transparent plastic, such as but not limited to a solid transparent acrylic material, a solid transparent resinous material, or a transparent polycarbonate material, such as those sold under the trade names of LEXAN®, PLEXIGLASS® and the like, can be used.
Each of the block adapter(s) 100 , can have a flat front face 110 , convex curved top 112 , fastener through-hole 115 , convex curved bottom 118 , flat rear face 120 , left flat side 130 , securing bar through-hole 135 , and a right flat side 140 .
The novel connecting block adapters 100 can have a generally rectangular block configuration and be approximately 1½ inches wide by approximately 2 inches tall by approximately 1¼ inches thick. Other dimensions can be sized as needed. The connecting block adapters 100 can have two through-holes 115 , 135 , each perpendicular to one another as shown. A hole 115 for the fastener 10 can be approximately ½ inch in diameter, and the perpendicular hole 135 for a securing bar 20 can be approximately ¾ inch in diameter. The securing bar 20 can be a metal bar or pipe having an outer diameter sized to fit into the securing bar hole 135 in the connecting block, and be long enough to be wider than the width of the window opening.
The novel connecting block adapters 100 can be formed from plastic, wood, and metal, such as but not limited stainless steel, galvanized metal, aluminum, and the like. Additionally, the connector block adapters 100 can be formed from the same transparent material as the rigid transparent panels 30 . The connector block adapters 100 can each be solid, honeycomb inside, or hollow.
FIG. 3 is a partial perspective interior assembled view of a window opening 220 to a building or house with the novel block adapters 100 and securing bar 20 and fasteners 10 of FIG. 1 on the inside of the opening, with exterior plastic panel 30 on outside of window opening. FIG. 4 is an interior view of the window opening 220 with block adapters 100 , securing bar 20 and fasteners 10 and exterior plastic panel 30 on the window opening 220 of FIG. 3 . FIG. 5 is an exterior view of the window opening 220 with block adapters 100 , securing bar 20 and fasteners 10 with plastic panel 30 on the window opening 220 of FIG. 3 .
FIG. 6 is a flowchart of the installation steps to install a transparent plastic panel 30 over an opening shown in FIGS. 3-5 , using the connecting block adapters 100 .
Referring to FIGS. 3-6 , an opening 220 , such as a window opening in a building structure or house structure having broken glass 225 , needs to be secured. The novel invention can install rigid transparent or opaque plastic panels 30 over the exterior of window openings 220 using the novel connecting block adapters 100 .
The installer measures the window opening 220 to determine the size of the rigid transparent plastic panel 30 that is needed. The correct size is cut to cover part or the entire glass area 225 of the window opening 220 . Next, the installer places the cut panel 30 over the exterior of the glass area 225 of the window opening 220 .
Next, the installer places the novel connecting block adapters 100 on the bottom left and bottom right of the interior of the window opening 220 , so that the connecting block adapters 100 overlap the bottom frame or casing of the window opening 220 . The connecting block adapters 100 can be oriented vertically, or horizontally or even at an angle as needed.
Next, the installer will drill holes using a drill through the fastener hole(s) 115 of the connecting block adapter 100 and through the transparent plastic panels 30 . A hole size in the plastic panels 30 can be approximately ½ inch. Alternatively, the connecting block adapters 100 can only have a securing bar hole 135 , so that the fastener hole(s) 115 are drilled also therethrough.
Next, fasteners 10 such as bolts with nuts with washer(s) 16 can be used to secure the connecting block adapters 100 to the inside of the window and opening 220 . The securing bar 20 can be slid through both connecting securing bar holes 135 in the connecting block adapters 100 so that outer ends of the securing bar 20 abut against interior portions of the frame/casing 210 on both sides of the window opening 220 . Caps 22 can be used on the outer ends of the bar 20 .
As a result, the exterior transparent plastic panel 30 can be sandwiched between the bolt head(s) 12 of the fasteners 10 and the securing bar 20 . The bolt heads 12 can be on the outside of the window opening 220 and the nuts 18 on the inside rotated about the threads 14 of the fasteners 10 . Alternatively, bolt heads 12 can be on the inside and nuts 18 on the outside. Additionally, washers 16 , such as but not limited to locking washers can also be used as needed with the fasteners 10 . Additionally, other types of fasteners 10 can be used, such as but not limited to carriage bolts, and screws, and the like.
In the preferred embodiment, other generic types of fasteners 10 , such as but not limited to bolts, screws and the like, can also be used on the top edge(s) of the transparent plastic panel 30 to attach the panel to the frame/casing 210 , without using the novel connecting block adapters 100 . Additionally, the novel connecting block adapters 100 with another securing bar 20 can also be placed over the top right and top left transparent plastic panels 30 and similarly attached so that four block adapters 100 and two securing bars 20 can be used. The transparent rigid plastic panels 30 can be easily removed from covering the opening(s) by reversing the installation steps referenced above.
The connecting block adapters 100 can be an object of suitable size, shape, material and strength, intended to accept a threaded or unthreaded fastener in order to secure a cover over an opening. The connecting block adapters 100 can utilize holes of suitable size to insert a securing bar and the above mentioned fastener.
The fasteners 10 can be passed through the primary surface, the covering, to be secured. As mentioned, fastener holes 115 and/or securing bar holes 135 of suitable size can be drilled through the primary surface to allow the fasteners 10 to pass through. A suitable stop is on, or must be placed on the fastener to prevent it from going through the primary surface. The number of holes drilled and the number of connecting block adapters 100 used depends on the size of the opening to be covered and the type of covering material used.
The connecting block adapters 100 are generally placed over the securing bar 20 . The securing bar 20 must be of sufficient length to allow it to span greater than the width of the window opening 220 . The fasteners 10 that have already passed through the primary surface are then passed through the connecting block adapters 100 and secured against the surface with whatever pin, washer, nut, or other component required by the fasteners 10 . The fasteners 10 can then be tightened against the connecting block adapters 100 to cause the securing bar 20 to tighten against the side surfaces of the opening 220 thereby drawing the primary surface (the cover) tightly against the opposite side of the opening.
Although the connecting block adapters 100 shown have a generally rectangular configuration, other geometrical shapes can be used
Although the openings described in the preferred embodiment in relation to the Figures show a window opening, the invention can be used with other openings, such as but not limited to openings for doors and the like.
While the invention has been described, disclosed, illustrated and shown in various terms of certain embodiments or modifications which it has presumed in practice, the scope of the invention is not intended to be, nor should it be deemed to be, limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended.
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Systems, devices, apparatus, kits and methods of attaching rigid plastic panels over door and window openings of vacant and/or damaged buildings and houses, with connecting block adapters attached to the lower corners of the panels by fasteners, and a security bar slid into holes on the adapters with ends that abut against portions of the adjacent frames and casings about the openings. The fasteners through can fasten the adapters to the outside of the plastic panels which cover the outer opening.
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FIELD OF THE INVENTION
The present invention relates to an improved lithium halide primary cell, a depolarizer therefor and a method for making same. In particular, the invention is directed to lithium iodine cells in which the depolarizer or cathode material is a pelletized particulate mixture of an organic polymer consisting of poly-2-vinylpyridine (P2VP) or poly-2-vinylquinoline (P2VQ) iodine and a charge transfer complex of said organic polymer and iodine. The depolarizers are hereinafter collectively referred to as P2VP+P2VP.n 1 I 2 +n 2 I 2 were n 1 >0 and n 1 +n 2 =3 to 30.
BACKGROUND OF THE INVENTION
The present invention provides a lithium halide primary cell having a shelf life extendable to more than ten years by utilizing a pelletized depolarizer consisting of P2VP+P2VP.n 1 +n 2 I 2 wherein n 1 >0 and n 1 +n 2 is equal to 3 to 30 (parts of I 2 for each part of total organic). Preferably n 1 n 2 is equal to 15 to 26 parts of I 2 for each part of organic in the depolarizer. The cells of the present invention are particularly useful in electric watch, calculator and heart pacer applications.
U.S. Pat. Nos. 3,660,163 and 3,674,562 disclose batteries utilizing charge transfer complexes which are mixed with excess amounts of iodine. In particular, U.S. Pat. No. 3,674,562 teaches a novel cathode material which is "plastic" that is a pliable, putty-like solid. This material when used as a cathode in lithium primary cells has a low internal impedance and a relatively low self-discharge as measured by its heat of discharge. Cells manufactured in accordance with U.S. Pat. No. 3,674,562 are especially well suited for use in long-life, low current drains applications such as heart pacers.
What has been found is that 3-30 parts of iodine can be mixed with each part of the polymer P2VP or P2VQ having a weight average molecular weight* of above about 1×10 3 and pelletized without becoming plastic. Unlike the "plastic" depolarizer, P2VP.nI 2 and P2VQ.nI 2 , material of U.S. Pat. No. 3,674,562, the pelletized P2VP+P2VP.n 1 I 2 +n 2 I 2 (where n 1 +n 2 =3 to 30) depolarizer of the present invention has initially unacceptable electrical characteristics for battery applications. Typically, the initial impedance of a cell manufactured with the pelletized depolarizer of the present invention is quite high, for example, impedances from 2,000 ohms to 20,000 ohms are experienced. This compares with initial impedances of cells made with the material disclosed in U.S. Pat. No. 3,674,562 which have impedances in the range of about 30 to 300 ohms.
It was found, however, that initial impedances greatly diminish with time so that the cell "acquires" the appropriate electrical characteristics for battery applications. In fact, cells made in accordance with the present invention result, after significant discharge, in impedances less than those made from the plastic depolarizer. In certain instances, the internal impedance in batteries of the present invention was less by a factor of five than those made with plastic depolarizers.
Generally, it has been well known to use various charge transfer materials, including P2VP and P2VQ, for complexing with halides, normally iodine, for use as depolarizers. Also, it has been equally well known that such materials could be pelletized for use in primary cells, U.S. Pat. Nos. 3,438,813 and 3,660,164. The depolarizer is each instance was in the form of a complex wherein the halogen comprises from 50 to 71% by weight of the complex. Cells produced in this manner had relatively short operating lives. Another proposed approach has been to utilize substantially pure iodine pellets having an additive of an electrically conductive material therein to which a coating of polyvinyl pyridine iodine is applied to the outer surface. U.S. Pat. No. 3,937,635. Typically, high portions of uncomplexed iodine increased the internal cell resistance. Pelletized cells having a charge transfer complex mixed with iodine in a ratio of 3 to 10 were found to have useful electrical properties. U.S. Pat. No. 3,660,163. The advantages of the greater iodine content, however, were achieved by forming the complex and iodine in the plastic state. See also U.S. Pat. No. 3,674,562.
It is, accordingly, an object of the present invention to provide a lithium halide battery in which the depolarizer is a pelletized particulate and comprises either P2VP+P2VP.n 1 I 2 +n 2 I 2 or P2VQ+P2VQ.n 1 I 2 +n 2 I 2 where n 1 >0 and n 1 +n 2 =3 to 30. The batteries made in accordance with the present invention have significant advantages over prior art batteries. These advantages will become apparent from a perusual of the following description of the invention taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional elevation taken along line I--I of FIG. 2 of a battery utilizing the disc depolarizer of the present invention; and
FIG. 2 is a plan view of the battery shown in FIG. 1.
DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 and 2, battery 10 of the present invention comprises an outer casement member 11, preferably made from stainless steel and shaped in the form of a cup to facilitate assembly. A pair of lithium anode discs 12 and 13 are positioned in member 11 with a disc 14 of pelletized depolarizer interposed between discs 12 and 13. Preferably, lithium discs 12 and 13 are of a configuration substantially conforming to the inner configuration of encasement member 11 to achieve a tight fit for electrical contact. Depolarizer disc 14 is dimension slightly smaller than the lithium anode discs to avoid electrical contact with encasement member 11.
Depolarizer disc 14 preferably includes a cathode current collector comprising a metal screen 16 made, for example, of nickel and having cathode lead 17 electrically connected thereto. Lead 17 is sheathed in an insulating material such as Halar® and is routed over lithium disc 13 to the center thereof. A top member 18 having opening 19 in its center is hermetically bonded to encasement 11. Lead 17 is positioned through opening 19 and sealed therethrough as the positive terminal.
It is clear that battery 10 may be otherwise embodied by using only one lithium disc or by isolating the lithium disc from case 11 and placing pellet 14 in contact therewith. In the latter case, electrical lead 17 would be connected to the lithium anode. Also, both the anode and depolarizer pellet 14 can be insulated from case 11 to form a bipolar battery requiring two electrical leads.
It has been discovered that pelletization of the organic polymer P2VP or P2VQ and I 2 results in a novel depolarizer that can be used in lithium halide primary cell 10. The material, P2VP+P2VP.n 1 I 1 +n 2 I 2 , greatly facilitates the manufacture of cells by permitting the use of automatic handling equipment. More importantly, the electrical characteristic of the depolarizer provide certain advantages over a depolarizer consisting of plastic P2VP.nI 2 or P2VQ.nI 2 . A battery utilizing pelletized particulate P2VP+P2VP.n 1 I 2 +n 2 I 2 will exhibit electrical characteristics quite different from batteries prepared in accordance with U.S. Pat. No. 3,674,562. Batteries prepared in accordance with the present invention have an open circuit voltage of about 2.8v (the same as conventional batteries), but the internal impedance of the batteries is quite high. Although the initial impedance of the pellet is unsuitably high, it was unexpectedly found that the initial impedance naturally decreases at a very fast rate. For example, decreases of between 50 to 60% during the first week are normal. Also, by gently warming the cells (<100° C.), decreases in the impedance can be greatly accelerated. These decreases in internal impedance increase the voltage delivered by a battery under load. This increase typically continues until the decrease in internal impedance ends.
Another impedance factor associated with a battery using the pelletized depolarizer of the invention relates to the electrolyte. When such a battery is under load, the thickness of that component, lithium iodide, increases and consequently the impedance of that component of battery increases. Thus, as the battery is discharged, the total battery impedance will decrease as the pellet impedance decreases and will begin to increase as the increasing LiI 2 becomes the dominating factor.
It was originally thought that the noted characteristics were due to a transformation of the pellet into the "plastic" state in U.S. Pat. No. 3,674,562. However, it has been found that such is not the case; the pelletized depolarizer remains in substantially its initial form. It is presently believed these characteristics are associated with the formation of the electrolyte layer (LiI 2 ) in the pelletized P2VP+P2VP.n 1 I 2 +n 2 I 2 which has a large number of grain boundaries that promote ion migration. Also, mechanical defects are formed in the lithium halide electrolyte layer which provide channels for ion migration. In conventional cells, including those of the prior art which utilized pelletized cathode materials, impurities were added to create crystal defects in the lithium iodine layer. For example, it has been common practice to add impurities such as divalent ions (aluminum oxide and silicon dioxide are common examples) or waters of hydration.
In the present invention, no impurities are added. Defects are believed to form in the crystaline structure of the electrolyte which provide broader channels for ionic flow. The evidence indicates that the morphology of the depolarizer governs to a great extent the morphology of the lithium iodide layer. In prior P2VP.nI 2 or P2VQ.nI 2 cells the plastic state permitted a relatively perfect layer to form causing large regular crystals. The pelletized depolarizer, on the other hand, promotes a cracked layer in which crystal defects or disorders occur because of the mechanical arrangement of the physical structure of the depolarizer materials. Whatever the physical-mechanical reason, the pelletization of the P2VP+P2VP.n 1 I 2 +n 2 I 2 has resulted in cells having greater power density than those which utilized such material in the plastic state.
Additionally, the mechanical defects which promote ion migration also permit iodine vapor diffusion which results in self-discharge properties of the cells. For commercial purposes it is possible to trade higher self-discharge by reducing the internal impedance for reducing electrical data scatter. The preferred iodine ratio is from 18 to 26 parts of iodine for each part of organic (both complexed and uncomplexed). Higher iodine ratios reduce cracking (lower grain boundaries) and cause the formation of larger, more perfect crystals. The higher iodine ratios result in lower self-discharge, but never as low as that achieved by plastic depolarizer materials. The low iodine ratios e.g., 5:1 to 8:1, promote less perfect crystals and higher self-discharge. Cells constructed with these lower ratios have a high power density which makes them useful in short lived applications such as hearing aids. Accordingly, in the preferred range of iodine, the end of life characteristics can be extended.
In manufacturing depolarizer pellets, the iodine is ground in a ball mill into a particulate having a size of less than -70 mesh and the polymer is ground to a size of less than -100 mesh and preferably -150 to -200 mesh. It has been found that the particle size of the polymer and iodine as well as the molecular weight of the polymer and pellet density influence the initial cell impedance and the time necessary for the cell to reach full activation. The smaller the particle size, the lower the cell impedance with the size of the polymer having a greater effect than size of the iodine.
The particulate iodine and polymer are mixed together in the preferred ratio of 18 to 26 parts of iodine to one part of polymer. The mixture is placed in a die of the desired configuration and formed into a pellet with a pressure of from about 5,000 to 15,000 psi. Unlike prior pelletized depolarizers which used stoichemetric amounts of iodine, the pellets of P2VP+P2VP.n 1 I 2 +n 2 I 2 are not brittle. They retain their original shape, but have a slight tackiness for electrical contact.
By modifying the method set forth in U.S. Pat. No. 3,674,562, the same amount of polymerization initiator (n-butyl-lithium) is used, but it must be added much slower to allow the formation of longer polymer chains or by forming polymerization at a lower temperature. Otherwise a low molecular weight polymer is obtained which when mixed with iodine becomes plastic as disclosed in that patent. The precipitate is vacuum dried and ground as above. The increased polymer length permits mixing with the iodine without plasticity and subsequent pelletization of the mixture. Commercially pure grades of P2VP are useful in the present invention and do not result in a plastic depolarizer inasmuch as they normally have a molecular weight of from 6,000 to 13,000.
As mentioned above, the initial impedance (representative of depolarizer impedance) of a battery having the plastic depolarizer of U.S. Pat. No. 3,674,562 is much lower than batteries having the pelletized depolarizer of the present invention. However, the slope of the curve representative of impedance as a function of time (electrolyte layer) is less in the batteries of the present invention and intersect those curves of the batteries with plastic depolarizer within a relatively short time. Accordingly, batteries having the pelletized depolarizers of the present invention have significantly better end of life characteristics than prior plastic depolarizer cells having an equivalent amount of iodine. In batteries of the present invention, increasing the iodine ratio from 15:1 to 26:1 increases the end of life from 3 years to 10 or more years.
The following tables (A and B) compare a lithium anode enclosed battery made with the depolarizer of U.S. Pat. No. 3,674,562 (A) with similar battery made with the pelletized depolarizer of the present invention (B). Both batteries consisted of 15 to 1 by weight ratio of iodine to P2VP and both exhibited an open circuit voltage of 2.8 volts. The test were conducted at 37° C.
TABLE A__________________________________________________________________________ ELAPSEDDATE TIME (Mos.) VOLTS Z 50K 1K RDC LOADYR DAY UNDER LOAD (MV) (OHMS) (MV) (MV) (OHMS) (OHMS) MAHR COMMENTS__________________________________________________________________________76 317 0.0 2807.8 27 2803 2705 37 9999K 076 318 0.0 2807.4 28 2803 2702 38 1000K 076 321 0.1 2807.4 30 3803 2693 42 1000K 076 322 0.1 2807.0 31 2802 2686 44 1000K 076 323 0.2 2807.2 32 2802 2680 46 1000K 076 324 0.2 2807.2 34 2802 2673 49 1000K 076 325 0.2 2807.2 36 2801 2662 53 1000K 076 329 0.4 2806.9 42 2800 2634 64 1000K 176 336 0.6 2806.5 59 2797 2574 88 1000K 176 343 0.8 2806.2 85 2793 2494 123 1000K 276 348 1.0 2805.8 112 2789 2421 155 1000K 276 350 1.1 2805.7 129 2786 2371 179 1000K 276 357 1.3 2805.0 168 2780 2282 224 1000K 376 364 1.5 2804.2 208 2774 2197 270 1000K 377 5 1.7 2803.7 249 2768 2109 321 1000K 477 12 1.9 2803.2 282 2763 2041 364 1000K 477 19 2.2 2802.7 317 2757 1962 418 1000K 477 24 2.3 2802.4 339 2755 1923 446 1000K 577 24 2.3 2802.8 337 2757 1919 450 1000K 577 26 2.4 2802.3 353 2753 1887 473 1000K 577 33 2.6 2801.8 379 2749 1840 510 1000K 577 40 2.9 2801.4 410 2746 1788 553 1000K 677 47 3.1 2801.2 433 2743 1752 584 1000K 677 54 3.3 2800.8 448 2741 1716 617 1000K 777 61 3.6 2800.7 476 2738 1679 653 1000K 777 68 3.8 2800.3 512 2734 1629 702 1000K 877 73 4.0 2800.3 526 2732 1602 731 1000K 877 73 4.0 2800.3 527 2733 1602 731 1000K 877 82 4.2 2799.9 557 2729 1564 772 1000K 977 103 4.9 2795.7 568 2724 1509 836 1000K 1077 145 6.3 2797.8 738 2709 1354 1044 1000K 1377 257 10.0 2795.4 1152 2673 1070 1579 1000K 2077 313 11.8 2794.9 1341 2657 971 1841 1000K 2477 361 13.4 2794.2 1551 2639 884 2118 1000K 2778 3 13.7 2793.9 1587 2636 867 2180 1000K 2878 30 14.5 2793.5 1693 2629 833 2305 1000K 3078 60 15.5 2793.3 1786 2623 809 2405 1000K 32CHANGE/MONTH -0.4 122 -9 -44 155 ON LAST 5 GOOD POINTS AT 1000K__________________________________________________________________________ LOAD
TABLE B__________________________________________________________________________ ELAPSEDDATE TIME (mos.) VOLTS Z 50K 1K RDC LOADYR DAY UNDER LOAD (MV) (OHMS) (MV) (MV) (OHMS) (OHMS) MAHR COMMENTS__________________________________________________________________________76 335 0.0 2807.8 17860 1945 136 18742 9999K 0 -170 Mesh P2VP, -20076 336 0.0 2742.7 12250 2109 200 12242 1000K 0 Mesh I.sub.276 338 0.1 2748.2 8176 2261 294 7968 1000K 0 Sieve Size76 339 0.1 2490.5 88030 1 1 1042 1000K 0 BAD DATA POINT76 341 0.2 2751.7 6364 2339 371 6117 1000K 076 343 0.2 2754.3 5603 2373 414 5368 1000K 076 348 0.4 2758.2 4344 2432 518 4097 1000K 176 350 0.5 2757.5 4072 2444 546 3830 1000K 176 357 0.7 2758.4 3187 2487 665 2969 1000K 176 364 0.9 2761.2 2518 2525 796 2326 1000K 277 5 1.1 2763.0 2167 2545 885 1993 1000K 277 12 1.4 2766.3 1701 2570 1006 1641 1000K 377 19 1.6 2767.7 1662 2578 1059 1511 1000K 377 26 1.8 2769.4 1424 2596 1167 1284 1000K 477 33 2.0 2770.0 1299 2603 1225 1176 1000K 477 40 2.3 2771.7 1121 2616 1328 1012 1000K 577 47 2.5 2772.7 992 2626 1439 858 1000K 577 54 2.7 2773.8 854 2636 1501 784 1000K 677 61 3.0 2774.5 756 2643 1586 691 1000K 677 68 3.2 2775.5 658 2652 1656 622 1000K 677 75 3.4 2776.3 506 2658 1710 573 1000K 777 82 3.7 2777.2 525 2663 1764 526 1000K 777 89 3.9 2778.0 466 2670 1816 485 1000K 877 96 4.1 2778.8 422 2676 1859 453 1000K 877 103 4.3 2779.5 335 2681 1898 425 1000K 977 110 4.6 2780.2 355 2686 1929 404 1000K 977 117 4.8 2780.8 327 2691 1950 391 1000K 1077 145 5.7 2782.3 255 2707 2031 342 1000K 1277 257 9.4 2785.2 220 2730 2082 320 1000K 1977 313 11.2 2783.8 266 2729 1988 383 1000K 23CHANGE 0.6 -12 6 10 -3 ON LAST 5/MONTH GOOD POINTS AT 1000K__________________________________________________________________________ LOAD
As can be seen from the table, prior art battery (A) was discharged on a 1000K ohm load an an initial impedance of 25-50 ohm which is typical. As the discharge proceeded, the internal impedance increased due to the build-up of the electrolyte layer. As a result of that increase, the voltage of the cell slowly decreased. After approximately 2.6 months the voltage decay rate was 2.1 milli-volts/month and the impedance had increased by 134 ohms/mon.
The battery (B) using the depolarizer pellet of the present invention had an initial impedance of 17,860 ohms. This impedance decreased by 50-60% the first week and continued to decrease thereafter, but at a much slower rate. As this decrease continued, the voltage under load delivered by the battery increased. In other tests impedances after 5 months at 37° C. were approximately 300 to 400 ohms.
Tables C, D (same batter as B), E and F show cells made in accordance with the present invention in which the impedance decreased when under 1000K ohm load.
TABLE C__________________________________________________________________________ ELAPSEDDATE MOS. VOLTS Z 50K 1K RDC LOADYR DAY UNDER LOAD (MV) (OHMS) (MV) (MV) (0HMS) (OHMS) MAHR COMMENTS__________________________________________________________________________76 335 0.0 2807.0 30130 1480 73 12355 9999K 0 170 P2VP, -200 I.sub.276 336 0.0 2598.7 20260 1766 129 17809 1000K 076 338 0.1 2640.5 12660 2014 220 10077 1000K 076 339 0.1 2648.3 60170 2030 213 10639 1000K 076 341 0.2 2657.7 9984 2117 282 7704 1000K 0 BAD Z DATA POINT76 343 0.2 2664.2 8772 2159 317 6763 1000K 076 348 0.4 2677.2 7031 2240 418 4905 1000K 176 350 0.5 2677.5 6605 2252 437 4647 1000K 176 357 0.7 2684.2 5362 2305 546 3527 1000K 176 364 0.9 2692.5 4094 2349 661 2759 1000K 277 5 1.1 2698.3 3790 2376 748 2331 1000K 277 12 1.4 2706.7 3246 2407 855 1926 1000K 377 19 1.6 2710.8 2053 2427 946 1654 1000K 377 26 1.8 2716.8 2512 2448 1041 1421 1000K 477 33 2.0 2719.7 2286 2461 1108 1279 1000K 477 40 2.3 2725.7 1990 2480 1216 1085 1000K 477 47 2.5 2730.2 1757 2497 1311 941 1000K 577 54 2.7 2735.2 1530 2513 1408 815 1000K 577 61 3.0 2739.2 1345 2526 1490 720 1000K 677 68 3.2 2744.2 1160 2541 1580 629 1000K 677 75 3.4 2748.0 1010 2554 1649 566 1000K 777 82 3.7 2752.4 056 2566 1717 510 1000K 777 89 3.9 2756.3 740 2578 1784 459 1000K 877 96 4.1 2759.7 646 2589 1835 423 1000K 877 103 4.3 2762.5 561 2600 1882 393 1000K 977 110 4.6 2765.3 493 2610 1922 363 1000K 977 117 4.8 2767.8 435 2620 1958 347 1000K 1077 145 5.7 2774.7 273 2654 2069 290 1000K 1177 257 9.4 2781.5 157 2705 2164 256 1000K 1977 313 11.2 2779.7 177 2708 2120 284 1000K 23Change/Month 2.1 -43 14 29 -11 On Last 5 Good Points AT 1000K__________________________________________________________________________ LOAD
TABLE D__________________________________________________________________________ELAPSEDDATE MOS. VOLTS Z 50K 1K RDC LOADYR DAYUNDER LOAD (MV) (OHMS) (MV) (MV) (OHMS) (OHMS) MAHR COMMENTS__________________________________________________________________________76 3350.0 2807.8 17860 1945 136 18742 9999K 0 -170 P2VP, -200 I.sub.2 (STANDARD MIX)76 3360.0 2742.7 12250 2109 200 12242 1000K 076 3380.1 2748.2 8176 2261 294 7968 1000K 076 3390.1 2490.5 88030 1 1 1042 1000K 0 BAD Z DATA POINT76 3410.2 2751.7 6364 2339 371 6117 1000K 076 3430.2 2754.4 5603 2373 414 5368 1000K 076 3480.4 2758.2 4344 2432 518 4097 1000K 176 3500.5 2757.5 4072 2444 546 3830 1000K 176 3570.7 2758.4 3187 2487 665 2969 1000K 176 3640.9 2761.2 2518 2525 796 2326 1000K 277 3 1.1 2763.0 2167 2545 885 1993 1000K 277 12 1.4 2766.3 1781 2570 1006 1641 1000K 377 19 1.6 2767.7 1662 2578 1059 1511 1000K 377 26 1.8 2769.4 1424 2596 1167 1284 1000K 477 33 2.0 2770.0 1299 2603 1225 1176 1000K 477 40 2.3 2771.7 1121 2616 1328 1012 1000K 577 47 2.5 2772.7 992 2626 1439 858 1000K 577 54 2.7 2773.8 854 2636 1501 784 1000K 677 61 3.0 2774.5 756 2643 1586 691 1000K 677 68 3.2 2775.5 658 2652 1656 622 1000K 677 75 3.4 2776.3 506 2658 1710 573 1000K 777 82 3.7 2777.2 525 2663 1764 526 1000K 777 89 3.9 2778.0 466 2670 1816 485 1000K 877 96 4.1 2778.8 422 2676 1859 453 1000K 877 1034.3 2779.5 335 2681 1898 425 1000K 977 1104.6 2780.2 355 2686 1929 404 1000K 977 1174.8 2780.8 329 2691 1950 391 1000K 1077 1455.7 2782.3 255 2707 2031 342 1000K 1277 2579.4 2785.2 220 2730 2082 320 1000K 1977 31311.2 2783.8 266 2729 1988 383 1000K 23CHANGE/MONTH 0.6 -12 6 10 -3 ON LAST 5 GOOD POINTS AT 1000K__________________________________________________________________________ LOAD
TABLE E__________________________________________________________________________ELAPSEDDATE MOS. VOLTS Z 50K 1K RDC LOADYR DAYUNDER LOAD (MV) (OHMS) (MV) (MV) (OHMS) (OHMS) MAHR COMMENTS__________________________________________________________________________76 3350.0 2807.2 39720 1170 43 57700 9999K 0 -100 +170 P2VP, -200 I.sub.276 3360.0 2545.2 35240 1340 60 39728 1000K 076 3380.1 2593.2 23560 1638 99 23681 1000K 076 3390.1 2604.3 21540 1699 110 21237 1000K 076 3410.2 2622.0 17980 1816 137 16882 1000K 076 3430.2 2634.7 15840 1894 161 14261 1000K 076 3480.4 2658.2 11590 2042 225 9962 1000K 176 3500.5 2662.7 10610 2073 243 9177 1000K 176 3570.7 2677.4 8291 2165 313 6919 1000K 176 3640.9 2690.2 6620 2237 388 5419 1000K 277 5 1.1 2695.4 5660 2274 440 4667 1000K 277 12 1.4 2701.9 4077 2312 503 3974 1000K 377 19 1.6 2704.7 4384 2332 544 3607 1000K 377 26 1.8 2708.3 3870 2358 605 3152 1000K 477 33 2.0 2707.9 3644 2366 634 2959 1000K 477 40 2.3 2712.4 3231 2388 697 2611 1000K 477 47 2.5 2715.5 2940 2406 755 2342 1000K 577 54 2719.2 2662 2422 812 2112 1000K 577 61 3.0 2722.2 2427 2436 868 1918 1000K 677 68 3.2 2725.4 2218 2450 928 1734 1000K 677 75 3.4 2727.9 2036 2461 981 1591 1000K 777 82 3.7 2730.8 1866 2473 1036 1459 1000K 777 89 3.9 2734.3 1697 2486 1105 1311 1000K 877 96 2736.3 1566 2495 1157 1209 1000K 877 1034.3 2738.5 1448 2504 1213 1111 1000K 977 1104.6 2740.7 1345 2512 1262 1033 1000K 977 1174.8 2742.7 1261 2519 1307 966 1000K 1077 1455.7 2751.8 928 2547 1491 734 1000K 1177 2579.4 2764.3 495 2589 1759 487 1000K 1977 31311.2 2764.9 433 2597 1853 414 1000K 22CHANGE/MONTH 3.7 -134 12 85 -87 ON LAST 5 GOOD POINTS AT 1000K__________________________________________________________________________ LOAD
TABLE F__________________________________________________________________________ELAPSEDDATE MOS. VOLTS Z 50K 1K RDC LOADUNDER LOAD (MV) (OHMS) (MV) (MV) (OHMS) (OHMS) MAHR COMMENTS__________________________________________________________________________76 3350.0 2810.5 36730 1301 54 44085 9999K 0 -100 +170 P2VP, -200 I.sub.276 3360.0 2548.8 20590 1503 80 29130 1000K 076 3380.1 2586.9 20260 1728 120 19273 1000K 076 3390.1 2595.3 18750 1774 129 17826 1000K 076 3410.2 2607.7 16410 1855 151 15154 1000K 076 3430.2 2616.9 14870 1910 169 13526 1000K 076 3480.4 2637.2 11670 2029 225 9891 1000K 176 3500.5 2640.8 10980 2051 235 9476 1000K 176 3570.7 2654.7 9014 2129 289 7525 1000K 176 3640.9 2666.9 7468 2194 347 6130 1000K 277 5 1.1 2672.3 6559 2228 390 5356 1000K 277 12 1.4 2679.5 5748 2266 443 4608 1000K 377 19 1.6 2683.5 5203 2290 481 4170 1000K 377 26 1.8 2687.9 4678 2315 529 3709 1000K 477 33 2.0 2689.2 4435 2325 551 3528 1000K 477 40 2.3 2694.4 3788 2348 602 3157 1000K 477 47 2.5 2698.7 3661 2367 650 2854 1000K 577 54 2.7 2702.7 3353 2303 697 2603 1000K 577 61 3.0 2706.2 3093 2398 744 2381 1000K 677 68 3.2 2709.8 2853 2413 795 2171 1000K 677 75 3.4 2712.7 2656 2424 838 2012 1000K 777 82 3.7 2716.9 2427 2440 898 1819 1000K 777 89 3.9 2720.7 2233 2452 959 1644 1000K 877 96 4.1 2723.0 2089 2461 995 1552 1000K 877 1034.3 2725.7 1949 2471 1043 1439 1000K 977 1104.6 2728.4 1823 2480 1095 1327 1000K 977 1174.8 2731.0 1713 2488 1190 1140 1000K 977 1455.7 2742.7 1266 2525 1358 893 1000K 1177 2579.4 2772.3 493 2621 1826 449 1000K 1977 31311.2 2776.8 402 2645 1897 406 1000K 22CHANGE/MONTH 7.5 -215 24 119 -129 ON LAST 5 GOOD POINTS AT 1000K__________________________________________________________________________ LOAD
Tables G, H, and I show decreases in the impedance under no load and when later subjected to a 50K ohm load show that nearly full capacity (250 mahr) was reached at approximately 5.7 months.
TABLE G__________________________________________________________________________ ELAPSEDDATE MOS UN- VOLTS Z 50K 1K RDC LOADYR DAY DER LOAD (MV) (OHMS) (MV) (MV) (OHMS) (OHMS) MHR COMMENTS__________________________________________________________________________77 13 0.0 2800.8 3639 2427 544 3802 9999K 0 STANDARD MIX, SCREEN 277 19 0.0 2800.7 2979 2462 636 3116 9999K 077 26 0.0 2792.8 1521 2552 1012 1604 9999K 077 33 0.0 2786.9 1109 2578 1211 1179 9999K 077 40 0.0 2780.5 830 2595 1393 897 9999K 077 47 0.0 2776.8 659 2607 1528 731 9999K 077 54 0.0 2775.7 556 2616 1627 628 9999K 077 61 0.0 2776.6 473 2625 1716 547 9999K 077 68 0.0 2777.7 411 2633 1792 404 9999K 077 75 0.0 2778.7 361 2640 1856 495 9999K 077 82 0.0 2779.3 326 2646 1906 400 9999K 077 84 0.0 2621.3 328 2660 1898 361 50K 07 87 0.1 2641.4 305 2581 1937 344 50K 477 89 0.2 2641.8 292 2582 1954 332 50K 6 71st DAY AFTER MFR.77 96 0.4 2641.3 270 2583 1983 313 50K 1577 103 0.6 2640.3 260 2582 1994 305 50K 2477 110 0.9 2638.7 263 2580 1986 309 50K 3377 117 1.1 2636.9 275 2578 1965 323 50K 4277 145 2.0 2624.4 370 2561 1842 405 50K 7777 257 5.7 2689.2 563 2619 1596 671 50K 220CHANGE/MONTH -296.1 11207 -290 -243 -114 ON LAST 5 GOOD POINTS AT 50K__________________________________________________________________________ LOAD
TABLE H__________________________________________________________________________ ELAPSEDDATE MOS. VOLTS Z 50K 1K RDC LOADYR DAY UNDER LOAD (MV) (OHMS) (MV) (MV) (OHMS) (OHMS) MAHR COMMENTS__________________________________________________________________________ STANDARD MIX,77 19 0.0 2802.5 8916 2352 370 6130 9999K 0 SCREEN 277 26 0.0 2797.5 1963 2562 873 2057 9999K 077 33 0.0 2794.3 1419 2600 1073 1495 9999K 077 40 0.0 2790.7 1099 2624 1239 1160 9999K 077 47 0.0 2733.2 88100 4 3 651 9999K 077 54 0.0 2723.5 89740 5 3 550 9999K 077 61 0.0 2724.9 89950 5 3 468 9999K 0 BAD DATA POINTS77 68 0.0 2722.0 89950 5 4 333 9999K 077 75 0.0 2784.5 527 2671 1689 601 9999K 077 82 0.0 2783.7 481 2676 1745 550 9999K 077 84 0.0 2648.2 481 2586 1739 507 50K 077 87 0.1 2678.2 444 2617 1794 478 50K 477 89 0.2 2681.8 423 2622 1818 460 50K 677 96 0.4 2685.5 339 2627 1838 430 50K 1577 103 0.6 2686.5 383 2628 1857 431 50K 2477 110 0.9 2685.7 416 2625 1798 479 50K 3377 117 1.1 2684.2 465 2621 1724 542 50K 4277 145 2.0 2679.2 572 2609 1573 691 50K 7977 257 5.7 2653.7 1267 2560 1070 1508 50K 222CHANGE ON LAST 5 GOOD/MONTH -225.0 4060 -251 -233 5236 POINTS at 50K LOAD__________________________________________________________________________
TABLE I__________________________________________________________________________ELAPSEDDATE MOS. VOLTS Z 50K 1K RDC LOADYR DAYUNDER LOAD (MV) (OHMS) (MV) (MV) (OHMS) (OHMS) MAHR COMMENTS__________________________________________________________________________77 13 0.0 2801.8 3281 2472 587 3511 9999K 0 STANDARD MIX, SCREEN 277 19 0.0 2800.7 2773 2497 665 2979 9999K 077 26 0.0 2791.9 1556 2571 987 1693 9999K 077 33 0.0 2785.7 1186 2593 1156 1801 9999K 077 40 0.0 2779.2 929 2609 1312 1030 9999K 077 47 0.0 2777.3 764 2621 1429 866 9999K 077 54 0.0 2777.9 658 2632 1518 759 9999K 077 61 0.0 2778.2 571 2641 1600 673 9999K 077 68 0.0 2779.7 507 2648 1668 607 9999K 077 75 0.0 2780.3 452 2654 1732 550 9999K 077 82 0.0 2780.9 410 2660 1784 506 9999K 077 84 0.0 2632.0 413 2567 1777 462 50K 077 87 0.1 2660.7 380 2597 1827 438 50K 477 89 0.2 2661.9 364 2599 1844 424 50K 6 71st DAY AFTER MFR.77 96 0.4 2661.0 345 2598 1866 407 50K 1577 1030.6 2659.2 351 2595 1854 415 50K 2477 1100.9 2655.7 386 2589 1798 458 50K 3377 1171.1 2651.7 442 2582 1719 523 50K 4277 1452.0 2629.8 644 2549 1506 727 50K 7877 2575.7 2688.9 1025 2611 1201 1258 50K 221CHANGE/MONTH -147.3 2394 -185 -217 3180 ON LAST 5 GOOD POINTS AT 50K__________________________________________________________________________ LOAD
The foregoing cell are to be compared to the cells shown in Tables A, J and K which utilize a plastic depolarizer. At 220 Mahr cells utilizing the pelletized depolarizer of the present invention exhibited a Z of 500-2000 ohms. The prior cells (plastic depolarizer) typically showed a Z of greater than 2,000 ohms. The only difference in the cells was the depolarizer.
TABLE J__________________________________________________________________________ELASPSEDDATE MOS. VOLTS Z 50K 1K RDC LOADYR DAYUNDER LOAD (MV) (OHMS) (MV) (MV) (OHMS) (OHMS) MAHR__________________________________________________________________________76 3170.0 2800.5 27 2801 2685 44 9999K 076 3180.0 2802.4 36 2796 2647 57 50K 076 3210.1 2797.5 98 2785 2470 131 50K 476 3220.1 2795.4 125 2781 2401 162 50K 576 3230.2 2793.9 144 2778 2357 104 50K 776 3240.2 2792.2 163 2775 2312 206 50K 876 3250.2 2790.0 185 2771 2262 231 50K 976 3290.4 2783.9 248 2759 2137 301 50K 1576 3360.6 2772.2 362 2737 1932 432 50K 2476 3430.8 2762.2 467 2718 1764 564 50K 3376 3481.0 2755.7 549 2706 1662 658 50K 4076 3501.1 2752.0 593 2699 1607 713 50K 4376 3571.3 2744.7 689 2605 1501 831 50K 5276 3641.5 2736.5 800 2670 1401 960 50K 6177 5 1.7 2728.5 912 2655 1303 1105 50K 6977 12 1.9 2722.7 1001 2644 1238 1215 50K 7877 19 2.2 2715.0 1118 2629 1160 1362 50K 8877 24 2.3 2712.8 1164 2626 1138 1408 50K 9477 24 2.3 2713.2 1159 2626 1137 1412 50K 9477 26 2.4 2711.0 1189 2622 1120 1448 50K 9777 33 2.6 2706.5 1270 2613 1076 1547 50K 10677 40 2.9 2700.2 1344 2602 1031 1658 50K 11577 47 3.1 2696.8 1416 2595 1003 1733 50K 12477 54 3.3 2692.2 1488 2587 970 1825 50K 13377 61 3.6 2687.2 1561 2578 937 1923 50K 14277 68 3.8 2681.2 1652 2567 904 2031 50K 15177 73 4.0 2677.8 1708 2560 882 2107 50K 15777 73 4.0 2677.9 1712 2561 884 2097 50K 16077 82 4.2 2672.3 1792 2551 855 2201 50K 16977 1034.89 2656.3 2019 2524 786 2479 50K 19677 1456.3 2460.3 4282 2224 405 5602 50K 247CHANGE/MONTH -365.2 2779 -340 -89 -567 ON LAST 5 GOOD POINTS AT 50K__________________________________________________________________________ LOAD
TABLE K__________________________________________________________________________ELAPSEDDATE MOS. VOLTS Z 50K 1K RDC LOADYR DAYUNDER LOAD (MV) (OHMS) (MV) (MV) (OHMS) (OHMS) MAHR__________________________________________________________________________ 76 3170.0 2808.2 26 2803 2695 41 9999K 076 3180.0 2802.7 37 2797 2639 61 50K 076 3210.1 2797.5 99 2787 2479 127 50K 476 3220.1 2795.5 121 2783 2421 154 50K 576 3230.2 2793.9 137 2780 2383 171 50K 776 3240.2 2792.5 153 2777 2342 191 50K 876 3250.2 2790.7 172 2774 2297 214 50K 976 3290.4 2785.8 227 2765 2178 278 50K 1576 3360.6 2778.2 324 2750 1992 395 50K 2476 3430.8 2769.0 384 2737 1877 476 50K 3376 3481.0 2762.7 414 2729 1821 520 50K 4076 3501.1 2760.2 440 2725 1775 559 50K 4376 3571.3 2759.2 519 2720 1681 647 50K 5276 3641.5 2755.7 604 2712 1594 737 50K 6177 5 1.7 2751.5 687 2703 1512 831 50K 7077 12 1.9 2748.0 758 2676 1450 908 50K 7977 19 2.2 2743.2 848 2687 1379 1006 50K 8877 24 2.3 2740.9 891 2683 1352 1047 50K 9577 24 2.3 2740.8 882 2683 1355 1042 50K 9577 26 2.4 2739.3 912 2680 1336 1070 50K 9777 33 2.6 2735.4 985 2672 1285 1152 50K 10677 40 2.9 2730.0 1080 2662 1233 1242 50K 11677 47 3.1 2725.5 1159 2654 1192 1317 50K 12577 54 3.3 2719.5 1241 2644 1144 1413 50K 13477 61 3.6 2713.2 1341 2632 1089 1533 50K 14377 68 3.8 2704.8 1471 2617 1029 1681 50K 15277 73 4.0 2697.7 1576 2604 979 1818 50K 15977 75 4.0 2696.3 1595 2602 973 1833 50K 16177 82 4.2 2684.7 1741 2582 913 2017 50K 17077 1034.9 2587.5 2943 2421 595 3584 50K 19777 1456.3 2284.2 7259 1975 261 9172 50K 246CHANGE/MONTH -3.2 2601 -2 0 -7471 ON LAST 5 GOOD POINTS AT 50K__________________________________________________________________________ LOAD
The ratio of iodine to P2VP or P2VQ may range widely from 3-30 to 1; however, a 3:1 ratio while having a desirable electrical properties is at the lowest practical capacity. A ratio of 30:1, on the other hand, approaches the upper limit with respect to internal impedance. A ratio of 15:1 is satisfactory, except that where such cells have been heated they have increased self-discharge which renders them useful for high current drain applications which require less than 10 year shelf lives. Where shelf lives are important as well as mild heating, higher ratios of iodine are preferred, for example, 18:1 to 22:1.
In such cells for use in electric watch applications, a self-discharge in terms of heat output of 10 μwatts has been established. A ratio of 20:1 decayed to 10 μwatts in 29 days, whereas it took a cell having a 15:1 ratio approximately 2,000 days. (Both cells were heated for 15 hrs. at 80° C.). A cell having 26:1 depolarizer had an initial self-discharge of 14 μwatts, but the impedance provided was sufficiently high to render a cell of only average electrical properties. Interestingly, cells with a plastic depolarizer and a ratio of 15:1 have low heat output, for example 5 μwatts at 60 days. The low heat output of the cells made with plastic depolarizers continues throughout the life of the cell since the internal impedance increases.
Accordingly, for long life pelletized cells, it is preferred to utilize a ratio of about 20:1 iodine to polymer. The pelletized depolarizer of the present invention provides multiyear batteries suitable for use in watches. While presently preferred embodiments of the invention have been described in particularity, the invention may be otherwise embodied within the scope of the appended claims.
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An improved lithium iodine battery, depolarizer therefor and method of making same in which the depolarizer comprises a pelletized particulate mixture of iodine, an organic polymer of either poly-2-vinylpyridine or poly-2-vinylquinoline and a charge transfer complex consisting of the selected organic polymer and iodine wherein the mixture contains from 3 to 30 parts of iodine for each part of total organic.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to provisional application Ser. No. 60/751,336 filed Dec. 16, 2005, incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to projection displays, and more particularly to projection display systems comprising a plurality of projectors arranged to display tiled images on a display screen.
BACKGROUND OF THE INVENTION
[0003] The quality of a projected image can be described by reference to a number of image characteristics. Each characteristic represents a potential source of distortion in the displayed image. Brightness and brightness uniformity are important characteristics of displayed images. Brightness distortion, also referred to as luminance distortion degrades the quality of a projected image to a viewer of the image. Most projectors do not project images at a constant luminance level across the entire display screen. Therefore, brightness distortion is a common problem in the design of projector display systems.
[0004] Brightness distortion has many possible sources. A common source of brightness distortion is due to inherent optical characteristics of lenses used in projection displays. This non uniformity is due to the design of the optics within the light engines of the projectors. Another possible cause for non uniformity is the projection lamps themselves. Regardless of the source of the luminance distortion, non-uniformity in luminance detracts from the displayed image in the eyes of a viewer of the image.
[0005] The luminance non-uniformity of a projector and its associated lens can become more pronounced when a plurality of projectors are employed in combination to display a single image on a display screen. Such an arrangement of projectors is as “tiling”. Tiling projectors and projector images on a display screen provides a larger image with higher overall resolution than can be obtained from a single projector. However, the technique of tiling images for display has drawbacks. Non-uniformity in luminance is often much more apparent in a composite image created by multiple projectors whose individual images are tiled together. This is particularly a problem in “seam” areas of the displayed image. Seams are created in those areas where images from a plurality of projectors overlap each other on the display screen. Brightness non uniformity in seam areas of a displayed tiled image is distracting to viewers and degrades the quality of the displayed image. Therefore, systems and methods for maintaining brightness uniformity in seam areas of tiled images are needed.
SUMMARY OF THE INVENTION
[0006] The present invention provides systems and methods for maintaining brightness uniformity in seam areas of tiled images.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Preferred embodiments of the present invention will be described below in more detail, with reference to the accompanying drawings, in which:
[0008] FIG. 1 is a block diagram of an example display system including two projectors according to an embodiment of the invention.
[0009] FIG. 2 is a block diagram of an example display system including four projectors according to an embodiment of the invention
[0010] FIG. 3 is a flow chart illustrating steps of a method for smoothing seams in a tiled display according to an embodiment of the invention.
DETAILED DESCRIPTION
[0011] FIG. 1 illustrates a display system 10 for projecting a video image 20 onto a display screen 40 . System 10 comprises a plurality of video projectors ( 160 , 260 ) arranged such that each projector ( 160 , 260 ) separately projects first and second portions ( 158 , 258 respectively) of image 20 onto display screen 40 . In the embodiment illustrated in FIG. 1 , projectors 160 and 260 comprise spatial light modulator (SLM) type projectors. According to one example embodiment of the invention projectors 160 and 260 comprise DLP™ projectors. DLP is a trademark of Texas Instruments. The light engine for each projector comprises any suitable technology, such as one or more Liquid Crystal Display (LCD) panels, Digital Light Processing (DLP) or Liquid Crystal on Silicon (LCOS). Nonetheless, those skilled in the art will recognize-that the present invention may be used. with other projectors, including those using other types of image generation technologies.
[0012] Each separately projected image portion 158 , 258 comprises a corresponding unique image portion ( 159 , 259 ) respectively of image 20 . Each separately projected image portion 158 , 258 further comprises a common image portion ( 60 L and 60 R) respectively of image 20 . For example, a first projector 160 projects first portion 158 of image 20 onto screen 40 . First portion 158 of image 20 comprises a unique image portion 159 , i.e., a portion of image 20 that is not projected by any other projector. First portion 158 of image 20 also comprises a common portion 60 L. Portion 60 L is a duplicate of image portion 60 R of image portion 258 . Common portion 60 L and common portion 60 R are projected to overlap each other on display 40 . The overlapping common portions 60 L and 60 R define a seam 88 of projected image 20 .
[0013] System 10 further comprises a video image separator 90 . A video signal representing video image 20 is provided to video image separator 90 . A processor 95 of image separator 90 separates the incoming video image signal into video image signal portions 106 and 206 . Video image signal portions 106 , 206 represent video image portions 158 and 258 respectively.
[0014] Video image separator further comprises a pixel brightness adjuster 27 . Pixel brightness adjuster 27 examines pixel values within overlapping image portions (e.g., 60 L and 60 R) of image signal portions 106 and 206 . Brightness adjuster 27 divides pixel values corresponding to overlapping pixels of overlapping image portions 60 L and 60 R (for example pixel 32 and 22 ) by the number of overlapping image portions comprising seam 88 . In the system illustrated in FIG. 1 seam 88 comprises two image overlapping image portions 60 L and 60 R. Therefore pixel brightness adjuster divides the brightness value for pixel 60 L and 60 R by two. When projected onto display 40 the combined brightness of pixels 60 L and 60 R will approximate the intended brightness corresponding to pixel 60 of input image 20 .
[0015] However, pixel values are represented by a limited number of bits. For example pixel values are commonly represented by 8 bits. Each of the 256 combinations of 8 bits corresponds to a different brightness level. If a brightness level does is not evenly divisible by the number of projectors it is not possible to accurately represent the original brightness value by a combination of equal lower values. In order to more closely approximate the original brightness value, pixel adjuster 27 determines the modulus (n) of the pixel brightness value to be adjusted, where n is the number of projectors comprising system 100 . Pixel brightness adjuster 27 adjusts the pixel brightness value for each projector based on the modulus (n) it determines.
[0016] In a two projector system pixel brightness adjuster 27 determines the modulus (2) of pixel brightness values of overlapping pixels. If the modulus (2) is 0, the original brightness value is evenly divisible by the number of projectors. In that case dividing the value by two and assigning equal values to each overlapping pixel will provide the original brightness value when the overlapping pixels are displayed.
[0017] If the modulus is 1, one of the overlapping pixels is assigned the integer portion of the original brightness value divided by the number of projectors. The other overlapping pixel is assigned a brightness value equal to the brightness value assigned to the other plus 1.
[0018] FIG. 2 illustrates a projector system 100 according to an alternative embodiment of the invention. Projector system 100 comprising four projectors 160 , 260 , 360 and 460 . Incoming video signal 12 is provided to video image separator 90 . Video signal 12 represents an image 20 to be displayed on screen 40 . Image separator 90 comprises a processor 95 and a pixel brightness adjuster 27 . Image separator 90 separates incoming video signal into video signal portions 81 , 82 , 83 and 84 . Each video signal portion represents a portion of image 20 . Similar to the embodiment of FIG. 1 each image portion 159 , 259 , 359 and 459 of image 20 comprises a unique image portion and an overlapping image portion. Overlapping image portions define seams 55 , 66 , 77 and 88 of displayed image 20 . In a configuration comprising four projectors arranged in accordance with FIG. 2 , an image area 73 comprises four overlapping image portions. Accordingly the brightness of a given pixel, for example pixel 800 , in image area 73 will be a combination of four pixel brightness values, one value supplied by each video signal portion 81 , 82 , 83 and 84 .
[0019] Pixel adjuster 27 of video separator 90 compensates for distortions in brightness by dividing the brightness value P of each pixel in area 72 , for example the brightness value of pixel 800 , by four (the number of projectors providing a pixel value for pixel 800 ). A value of P/4 is assigned to each overlapping pixel. To avoid loss of dynamic range pixel adjuster 27 also determines the modulus (n) for pixel brightness values of overlapping pixels, where n=4. If the modulus (4) of the brightness value is 0 each of the four overlapping pixel values is assigned a brightness value equal to the original brightness value divided by 4 (P/4). If modulus (4) of the brightness value is 1 a binary 1 is added to P/4 for one of the four overlapping pixels. If the modulus (4) of the brightness value is 2 a binary 1 is added to P/4 for two of the overlapping pixels. If the modulus 4 of the brightness value is 3 a binary 1 is added to three of the overlapping pixels. By adjusting pixel brightness values in accordance with the modulus (n) of the brightness of overlapping pixels, pixel brightness adjuster improves the dynamic range in the seams of image 20 .
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The present invention provides method for producing a substantially seamless video image on a display surface. The method comprises the steps of separately projecting at least a first and a second video image onto a display surface such that a seam is defined by overlapping portions of said first and second video images. Inside the seam, the brightness of video image is adjusted by adjusting pixels of said overlapping portions in accordance with a modulus determined by the number of overlapping portions defining the seam.
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This application is a Continuation of application Ser. No. 07/804,564, filed Dec. 10, 1991 and now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to fixed body conformal antenna systems and, more specifically, to a broad-band, wide field-of-view (FOV) direction finding (DF) interferometer array for missile type applications.
2. Brief Description of the Prior Art
High performance missile systems require highly accurate broadband DF performance such as low angle-of-arrival (AOA) error, low AOA error rates and large fields-of-view. In the prior art, the approach used to meet these requirements has been to mount an antenna array on a gimbal and to point the antenna array boresight in the direction of the target. The system generally used two fixed antennas to determine azimuth and two fixed antennas to determine elevation with the system generally switching between the two antenna pairs to constantly monitor azimuth and elevation. Maintaining the array boresight aligned with the target reduced DF errors by maintaining the targets within the useable FOV of the antenna array. Unfortunately, this approach suffered from several shortcomings which are described hereinbelow.
The use of fixed antennas permits only the look ahead type of operation and makes it difficult to recognize a target located on the ground or anywhere other than in the narrow field of view of the antenna system. Typically, an antenna array of this type has been placed upon a gimbal with array movement on the gimbal so that the array can look down for the desired target. The gimbal is then reoriented so that the boresight of the array, which is on an axis through the center of all of the antennas, is oriented at the target.
One major deficiency of the above described type of antenna system is inadequate DF performance due to amplitude and phase perturbations induced on the direction finding antennas by the multipath reflections between the bulkhead and gimbal structures and the radome inner surface. These multipath effects are compounded by the need to have broadband coarsely tuned radomes, reflective gimbal and missile seeker bulkhead structures and broad beam antennas.
Another deficiency encountered in a gimbal antenna system is the interaction and crosstalk between the individual antennas. This coupling corrupts the desired phase response between opposing antennas, consequently reducing the DF performance of the antenna array. The crosstalk can be caused by improperly terminated antennas which couple current onto the metallic gimbal structure and back into the other antennas.
A third problem encountered in the prior art of antenna DF systems is the need for the mechanical gimbals to point the interferometer array in the direction of the target. Gimbal systems generally increase cost and reduce reliability for long life cycle missile systems. In addition, radome cavity multipath perturbations on the antennas generally change as a function of gimbal angle, thereby creating target location variances on the DF performance within the FOV.
Also, the use of fixed antennas permits only the look ahead type of operation and makes it difficult to recognize a target located on the ground or anywhere other than in the narrow field of view of the antenna system.
Amplitude resolved phase DF processing would be a preferred DF processing approach for a low AOA error and low AOA error rate system, however the problems described above limit the ability of such systems to produce unambiguous phase DF. For an amplitude resolved phase DF process to operate properly, coarse amplitude DF angle resolution must be less than the minimum spatial phase ambiguity spacing. High axial ratio and non-linear DF transfer functions caused by the problems mentioned above force prior art systems to use amplitude only DF processing. Such systems are not capable of meeting high performance DF requirements because amplitude only DF systems typically have high polarization dependent AOA error envelopes and AOA error rates. These DF deficiencies become compounded by the problems mentioned above.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided an antenna system having improved large FOV broad-band DF performance, primarily for missile type applications. The system in accordance with the present invention also provides a higher reliability, lower cost solution for missile interferometric DF arrays than was available in the prior art. This is accomplished by eliminating the need for a gimbal and radome. The method and system used to accomplish these objectives are summarized in the basic properties described hereinbelow. The following method and system is summarized for improved DF performance in the elevation down direction and can be repeated to improve DF performance in the remaining three DF sectors.
Briefly, there is provided an array of antennas, preferably but not limited to a 3 by 2 configuration of two columns and three rows on a hemispherical structure (the discussion hereinbelow will be directed to a 3×2 antenna array, it being understood that other configurations can also be used), the antennas being conformal with the hemisphere dome or surface. Each of the antennas is pointed in a different direction whereby each antenna has its maximum sensitivity aligned with its individual boresight. The axis or boresight of each of the antennas passes through the center of the sphere upon which the hemispherical structure is based. While the discussion will be confined to spiral antennas which are preferred, it should be understood that any type of antenna can be used, preferably a broad band type of antenna and preferably a spiral type of broadband antenna.
The axis or boresight of each of the top four antennas is disposed at a predetermined angle relative to the array boresight, generally in the range of from about 20° to about 45° with an angle of 30° relative to the array boresight being preferred due to simplification of the mathematics involved by using this angle. The axis or boresight of each of the bottom two antennas is disposed at a predetermined angle relative to an axis inclined about 45° downward from the array boresight and preferably at an angle of 30° relative to the axis inclined 45° downward from the array boresight to simplify the mathematics involved. This structure replaces the radome, the gimbal, and the four antennas of prior art DF systems. It should be understood that the orientation of the antennas herein is not critical as long as such orientation is known since such orientation can be taken into account during computation.
The center of the two antenna columns is aligned with the missile elevation plane and the axis through the center of the top four antennas coincides with the missile boresight. The hemispherical surface is an electrically conductive or absorber structure which, when electrically conductive, is preferably a metallic structure, a metal plated plastic or graphite reinforced composite. This surface serves two functions, these being first, the support of the six spiral antennas, and second, the isolation by the electrically conductive hemisphere of the forward hemispherical antenna beams from any undesirable reflections that can originate from the spiral backlobes.
Each antenna is surrounded by an absorber ring that is used to isolate each antenna from undesirable surface currents which may adversely affect antenna performance. In addition, each antenna is covered by a low dielectric cover of a thermosetting or thermoplastic nonmetallic material that may be reinforced with glass or quartz for additional strength. Any engineering plastic that can stand up to the environment and which shields the antenna from the environment can be used with polypropylene being preferred.
The six antennas operate as two basic four element sub-arrays with displaced boresight locations, these being the look forward and the look down sub-arrays. The top and middle rows of the antennas comprise the look forward sub-array and the are used to form DF information in the forward DF sector. The look forward boresight is aligned with the missile boresight. The middle and bottom rows of the antennas comprise the look down sub-array and perform DF in the elevation down DF sector. The look down boresight is displaced from the look ahead boresight in the negative elevation direction. Two microwave switches are used to switch between the top and bottom rows of antennas and the middle row of antennas is shared for both modes of operation.
Direction finding (DF) information is first produced in the antenna planes which are rotated 45° from the azimuth and elevation planes. The antenna planes are planes through the array boresight and the center of two antennas, one antenna from each of the two columns which are from different rows of the array. An amplitude resolved phase DF technique is employed for this invention because of its high DF performance capability. Euler angle transformations are used to rotate the antenna plane DF information back into the vehicle coordinate system in standard manner.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are plan and elevation views respectively of the conformal antenna array in accordance with the present invention;
FIG. 2 is a diagram of the switching network employed in accordance with the present invention;
FIG. 3 is an exploded cross sectional view of the antenna system in accordance with the present invention;
FIG. 4 is an elevation view of the assembled conformal antenna array in accordance with the present invention;
FIGS. 5A and 5B illustrate typical azimuth and elevation performance respectively of the antenna system in accordance with the present invention against a rotating linear source polarization; and
FIG. 6 illustrates alternate applications of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, FIGS. 1A and 1B show the plan view of the six two arm spiral antennas 2 to 7 mounted on the aluminum hemispherical missile nose piece 1. The top four antennas 2, 3, 4 and 5 are used in the look ahead mode of operation while the bottom four antennas 4, 5, 6 and 7 are used in the look down mode of operation, with antennas 4 and 5 being used in both modes of operation. The axes of the antennas 2, 3, 4 and 5 are disposed at an angle of 30° with respect to the look ahead boresight 8. The look ahead array boresight 8 is co-aligned with the missile boresight and the look down boresight 9 is displaced from the look ahead boresight in the negative elevation direction by 45 degrees. The antennas 6 and 7 are disposed at an angle of 30° with the look down boresight 9. Antennas 4 and 5 are disposed at an angle of 30° with respect to both boresight axes 8 and 9. The axes of all of the antennas 2 to 7 intersect at the center 19 of the sphere containing the hemisphere 18.
For look ahead operation, antenna elements 5 and 2 are compared to form an AOA estimate in antenna plane 10. Antenna plane 10 contains the centers of antenna elements 5 and 2 as well as the look ahead boresight 8. In addition, antenna elements 3 and 4 are ratioed to form an AOA estimate in antenna plane 11. Antenna plane 11 contains the centers of antenna elements 3 and 4 as well as look ahead boresight 8 and is orthogonal to antenna plane 10. A standard Euler angle transformation is performed to rotate the antenna plane AOA estimates into the vehicle azimuth plane 12 and elevation plane 13. The rotation is 45° about the look ahead boresight.
In the look down mode, antenna elements 5 and 6 are ratioed to form an AOA estimate in antenna plane 14 and antenna elements 7 and 4 are ratioed to form an AOA estimate in the antenna plane 15 which is orthogonal to antenna plane 14.
The microwave switching network shown in FIG. 2 is used to switch from antennas 2 and 3 in the look ahead mode to antennas 6 and 7 in the lookdown mode as will be described hereinbelow. To obtain superior performance antennas 2, 5 and 6 comprise one matched antenna set and antennas 3, 4 and 7 comprise the other matched antenna set. The same Euler angle transformations are used to provide an azimuth AOA estimate and an offset elevation AOA estimate. The elevation AOA estimate for this mode is offset from the vehicle elevation plane by the angle delta 16 shown in FIG. 1B which is the angle between the look ahead boresight axis 8 and the look down boresight axis 9.
The AOA estimates are formed using an amplitude resolved phase DF processing method. The phase response between the compared antennas is modeled as a sine function and the amplitude difference between two compared antennas is modeled using a linear approximation. These relationships are described below.
For the amplitude:
⊖.sub.cr =Amp.sub.-- ratio/Amp.sub.-- slope-Boresight.sub.-- amp.sub.-- comp (1)
Where:
⊖ cr is the coarse amplitude AOA estimate in the antenna plane;
Amp -- ratio is the measured amplitude difference of the two compared antennas;
Amp -- slope is the calculated slope of the amplitude transfer function; and
Boresight -- amp -- comp is the measured amplitude difference at the array boresight.
For the phase:
ψ=(360×d(Sin ⊖)/λ)+N×360-boresight.sub.-- phase.sub.-- comp (2)
Where:
ψ is the measured phase difference between the two compared antenna;
d is the physical distance between the two compared antennas (e.g., 17)
⊖ is the fine AOA estimate in the interferometer plane;
N is the phase ambiguity integer;
Boresight -- phase -- comp is the measured phase difference at the array boresight; and
λ is the wavelength of the measured signal.
In the preceding description, ⊖ cr is first solved in Equation (1) hereinabove and then substituted into Equation (2) as ⊖ to solve for N. Equation (2) hereinabove is then re-evaluated to solve for ⊖. In order to accurately resolve all phase ambiguities with the coarse amplitude DF, the following criteria must be met:
For λ/d<1.0
Axial.sub.-- ratio/Amp.sub.-- slope<Sin.sup.-1 (λ/d)(3)
Axial -- ratio=ratio of the major axis to the minor axis of the incident source polarization ellipse.
Meeting the preceding criteria ensures that the coarse amplitude DF will be fine enough to resolve the smallest phase ambiguities.
The system described in this invention requires four sets of compensation values for each array axis. The compensation values are array boresight phase differences and d for the phase and array boresight amplitude difference and slope for the amplitude. These compensation values can be calculated at boresight and +/-15° in each antenna plane.
The Euler angle transformations used in this invention are shown below in their final form.
Az=Sin.sup.-1 (1/2).sup.1/2 ×(Sin(⊖.sub.1)+Sin(⊖.sub.2))! (4)
E1-Δ=Sin.sup.-1 (1/2).sup.1/2 ×(-Sin(⊖.sub.1)+Sin(⊖.sub.2))! (5)
Where:
⊖ 1 =Angle of arrival in antenna plane 10(15) (FIG. 1A) for the look ahead (down) mode;
⊖ 2 =Angle of arrival in antenna plane 11(14) (FIG. 1A) for the look ahead (down) mode; and
Δ=The angle bet ween the look ahead boresight 8 and the look down boresight 9 for the look down mode only (Δ=0 for the look ahead mode).
Referring now to FIG. 2, there is shown a microwave switching network to switch from antennas 2 and 3 in the look ahead mode to antennas 6 and 7 in the look down mode. There is shown a first switch 40 which connects antenna 2 to the switch 42 in the look ahead mode and cnnects antenna 6 to switch 42 in the look down mode. The switch 41 connects antenna 3 to the switch 42 in the look ahead mode and connects antenna 7 to the switch 42 in the look down mode. The antennas 4 and 5 are always connected to the switch 43. The switch 43 can switch between antennas 4 and 5 whereas switch 42 can switch between the outputs of switches 40 and 41.
It is further noted that the switching arrangement shown in FIG. 2 can be eliminated and that the output of each antenna or sensor constantly be sent directly to a processor whereat the outputs are individually collected, operated upon and utilized to provide the desired information and perform the desired functions without the requirement of the switching arrangement. This is accomplished using plural channel receivers which are coupled to the individual antennas.
FIG. 3 illustrates a cross section of the antenna array of the present invention along plane 13 and normal to plane 12 defined in FIG. 1. The microwave switching network (FIG. 2) and other electronics are contained in the receiver module 18. Attached to the receiver module are preformed phased matched cables 19. The phase matched cables 19 use blind mate press on RF connectors 20 which are guided into antenna holding cups 21. The press on connectors 20 are secured to the holding cup 21 bases by screws 22. The receiver module 18 is held in place by screws 23 that screw into bosses 24. The bosses 24, like the antenna holding cups 21, are integral components of the hemispherical dome 25.
Once the receiver module 18 is secured to the hemispherical structure 25, the antennas 26 are inserted into the antenna holding cups 21. Antenna mounting screws 27 secure the antennas 26 to the antenna holding cups 21. Absorber rings 28 are placed around the antennas 26 to absorb skin currents that may adversely perturb antenna performance. A weather seal gasket 29 is placed on the lip of the antenna holding cup 21 before the antenna cover 30 is secured to the hemispherical dome 25 with antenna cover mounting screws 31. The antenna covers 30 provide an environmental shield for the antennas 26 and are fabricated of structurally reinforced low dielectric polypropylene material. Attachment of the antenna cover mounting screws 31 completes the assembly of the described invention as shown in FIG. 4. At this time, the described invention can be slid over the front of a missile bulkhead 32 and secured in place with assembly mounting screws 33 and O-ring 34.
When constructed and operated as set forth above, the conformal array will provide azimuth and elevation angle of arrival (AOA) information as illustrated in FIGS. 5A and 5B wherein the left figure in each case shows results at one frequency and the right figure in each case shows results at another frequency. The azimuth plots in FIG. 5A show very accurate AOA, particularly within +/-40° of boresight, at two different frequencies. The elevation plots of FIG. 5B show very accurate AOA performance, particularly within +/-45° of boresight. The theoretical value in FIG. 5B is zero, thus accounting for the failure to see any data graphed in the left figure. These plots are actual measured data of an azimuth scan at zero elevation.
Although a particular arrangement of conformal spiral antenna array has been illustrated for the purpose of describing the manner in which the invention can be applied, it will be appreciated that the invention is not limited as such. FIG. 6 illustrates how the described arrangement can be expanded to provide full forward hemisphere FOV coverage by adding up to six more antennas to include look up, look left and look right arrays in addition to the look ahead and look down capability as described herein. FIG. 6 also illustrates, for example, the described invention supporting alternate mode sensors 35, such as millimeter wave antenna or infrared sensors disposed in the interstices between antennas 36 and preferably at the surface region of the hemisphere 37 to further enhance the operational capability of the described invention. For example, the antenna array composed of antennas 36 can be of the type described hereinabove with reference to FIGS. 1A and 1B whereas the antenna array composed of antennas or sensors 35 can be arranged to operate in the same manner as the array composed of antenna elements, but be designed to sense a form of energy or the like different from that sensed by other antenna array. For example, the first antenna array can be designed to detect standard RF energy to direct the array carrying device to a location close to the target whereupon the second antenna array, which can be infrared sensors or detectors, can be switched in to more accurately locate and/or define the target and perform desired operations against the target as a result of such location and/or definition.
Though the invention has been described with respect to certain particular preferred embodiments thereof, many variations and modification thereof will immediately become apparent to those skilled in the art. It is therefore the intention that the appended claims be interpreted as broadly as possible in view of the prior art to include all such variations and modifications.
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A fixed body wide field-of-view conformal antenna array suitable for broadband precision direction finding on missile platforms. The array is configured as multiple sub-arrays of spiral antennas that cover particular regions within the desired field-of-view of the entire array. A lower cost, more reliable and more accurate direction finding solution for missile needs is provided, primarily by the elimination of conventional radomes and antenna gimbal structures. The array can be configured to include multi-mode sensors.
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TECHNICAL FIELD
[0001] This disclosure generally relates to power transmission networks. More specifically, this disclosure relates to operating a DC power system from one or more AC or DC power generators. Even more specifically, this disclosure relates to improving efficiency of an AC generators when connected to a DC bus by providing a nearly constant load to the generators.
BACKGROUND OF THE INVENTION
[0002] Power transmissions networks can be made of AC systems, DC systems, or a combination of the two. AC power networks have conventionally been used throughout the world. However, DC power networks have certain advantages. DC power networks are easier to design and implement because they introduce no reactance into the power system. Higher efficiencies from generators can be achieved in DC systems because only real power is transmitted. Additionally, parallelization of power supplies is simple because no synchronization is required when additional supplies or loads are brought onto the network.
[0003] Therefore, in power networks that experience large swings in load on the generators and require reliable operation, a combination of DC systems and AC systems is beneficial. One example of such a power network is found on drilling platforms or vessels to operate onboard thrusters. Drilling vessels are not anchored in the ocean but are dynamically controlled to maintain a desired position in the ocean. Thrusters are propeller drives that can have variable rotation speed and azimuthal angle of the blades. They are used to maintain a position within specified tolerances of a drilling apparatus. These thrusters are operated by a power supply onboard the drilling vessel. Any failure of the power supply can lead to displacement of the vessel out of the tolerances of the drilling apparatus. In such a case, the drilling apparatus would need to be mechanically decoupled and recoupled after the power supply is restored and the position of the drilling vessel is corrected.
[0004] One method of facilitating a reliable power supply is to utilize a DC bus for powering thrusters and other components. Such a power transmission system is demonstrated in FIG. 1 . In such a system, the power supply is generally made of AC generators coupled to an AC-to-DC converter, such as AC-to-DC converter 112 . The AC-to-DC converter places power from the AC generators on an intermediate DC bus. Each motor or thruster, as well as other devices utilizing the intermediate DC bus, on board the drilling vessel is coupled to the intermediate DC bus through a DC-to-AC converter.
[0005] FIG. 1 is a block diagram illustrating a conventional DC voltage bus coupling multiple AC voltage generation systems to various loads. Power system 100 includes generators 102 . The generators 102 are coupled to an AC bus 104 through isolators 106 . The isolators 106 allow the generators 102 to be removed from the AC bus 104 when they are not used or are malfunctioning. The AC bus 104 is coupled to a transformer 108 to condition power for transmission to a line 110 . An AC-to-DC converter 112 is coupled to the line 110 and converts AC power on the line 110 to DC power for output onto an intermediate DC bus 120 . Coupled to the DC bus 120 are DC-to-AC converters 130 . The DC-to-AC converters 130 convert DC power on the DC bus 120 to AC power that most devices are designed to use. Coupled to the DC-to-AC converters 130 is a line 132 to which loads may be connected. A power dissipating device 134 is coupled to the line 132 , and the power dissipating device 134 may be, for example, a thruster. Additionally, a transformer 135 is coupled to the line 132 to condition power for a load 136 . The load 136 may be, for example, a light bulb.
[0006] Another example of the motor 134 may be the draw works onboard a drilling platform. The draw works is a machine that reels out and reels in the drilling line and conventionally includes a large-diameter steel spool, brakes, and a power source. Operation of the draw works to reel in drilling line may require the full capacity of the ship-board generators. However, there are operations conditions where the draw works may consume zero power. In reverse operation, the draw works may generate power that is placed back on the line 132 while gravity assists reeling out of the drilling line. The power load changes may occur nearly instantaneously.
[0007] Rapid changes in the load on the generator require the generator to increase power output to generate the power demanded by the load. Diesel generators are designed to consume fuel at an optimized rate in a small range of the available power output. Diesel fuel costs are the highest expense incurred by operating a diesel generator over its lifetime. Therefore, an operator desires to keep the generator operating in the power output range optimized for fuel consumption.
[0008] Turning now to FIG. 2 , a power output curve for a diesel generator are examined. FIG. 2 is graph illustrating the operation of a diesel generator. A curve 220 represents fuel consumption in kilograms per kilowatt-hour of the diesel generator at various engine loads (power output). A range between 0 and 100 percent of rated output demonstrates a variation in the kg/(kw/hour) ratio, or efficiency of fuel consumption In order to operate efficiently a range 230 of power load on the diesel generator should be maintained. If the load increases or decreases, the engine fuel consumption and efficiency changes.
[0009] In addition to fuel consumption issues, scrubbers on diesel generators that reduce the dangerous exhaust are sensitive to the volume of exhaust. Rapidly varying engine power changes the rate of flow of exhaust and chemical components of the exhaust. Because the scrubber is designed to operate optimally on a continuous and stable flow of exhaust, emissions output may not be minimized if the power load varies rapidly.
[0010] Further, dynamic performance of diesel generators is limited. That is, diesel generators may not increase power output rapidly enough to match an increasing power load on the diesel generator. Conventionally, additional diesel generators would be brought online if the rate of increase of power load exceeds the rate of increase of diesel generator power output. Neither diesel generator is operating efficiently and results in increased fuel consumption and express capacity when the power load peaks.
[0011] Referring now to FIG. 3 , generators and power loads will be examined in a conventional power plant. FIG. 3 is a block diagram illustrating power distribution on a conventional power plant 300 . The power plant 300 includes an AC generator 302 coupled to a switchboard 308 through an AC line 306 . The switchboard 308 is coupled to multiple loads. For example, typical shipboard and drilling loads are represented by a power dissipating device 312 coupled to the switchboard 308 by an AC line 310 . Additionally, the switchboard 308 is coupled to an AC-to-DC converter 318 . The AC-to-DC converter 318 is coupled to an AC line 316 and a DC line 320 . Additional loads may be coupled to the DC line 320 . For example, a light 322 may be coupled to the DC line 320 or a DC-to-AC converter 324 . The DC-to-AC converter 324 couples to additional AC loads such as a power dissipating device 326 . The power dissipating device 326 may be a draw works as described above or a motor. Each of the loads 312 , 322 , 326 produces different power loads on the AC generator 302 . The effect on the AC generator 302 will now be examined.
[0012] FIGS. 4A to 4E are graphs illustrating power consumption in a conventional power plant such as FIG. 3 . A line 402 in FIG. 4A indicates power consumption at the power dissipating device 312 . Shipboard loads such as the power dissipating device 312 operate as a constant load over long periods of time such as hours on the AC generator 302 . The line 402 is positive indicating consumption of power. A line 404 in FIG. 4B indicates power consumption at the power dissipating device 326 . Draw works such as the power dissipating device 326 operate as a varying load, which may change rapidly such as in milliseconds, on the AC generator 302 . The line 404 varies between positive and negative values indicating the load consumes power at some times and produces power at other times. A line 406 in FIG. 4C indicates power consumption at the light 322 . The light 322 operates as a constant load over long periods of time such as hours on the AC generator 302 .
[0013] Total power transferred through the AC-to-DC converter 318 is represented by adding the line 404 to the line 406 and is shown in a line 408 in FIG. 4D . The line 408 is total power consumption with respect to time of the DC line 320 . Total power delivered by the AC generator 302 is shown in a line 410 in FIG. 4E and is a sum of lines 408 , 402 . In the conventional power plant 300 power delivered by the AC generator 302 varies in time. This leads to undesirable qualities exhibited by the AC generator 302 as indicated above including inefficient fuel consumption and poor exhaust scrubbing.
[0014] Thus, there is a need for a power plant design that produces a substantially constant load on the AC generators and increases dynamic performance.
BRIEF SUMMARY OF THE INVENTION
[0015] A power plant includes an AC generator, an AC-to-DC converter coupled to the AC generator and a DC bus, and a switch coupled to the DC bus. The power plant further includes an active power compensation system coupled to the switch. The active power compensation system reduces power load variations in the power plant. The switch may include a DC-to-DC converter. The active power compensation system may include power consumption devices. The power consumption devices may be resistors. The power plant may also include power storage devices. The power storage devices comprise ultracapacitors. The ultracapacitors may be coupled to one or more microcontrollers. The one or more microcontrollers may regulate the ultracapacitors. The power storage devices may include batteries or rotating machines.
[0016] A method of reducing variations in a power load on a generator includes routing power between the generator and a power consuming device during a time when the power load on the generator is lower than a first level. The power consuming device may include a resistive element. The first level may be based, in part, on a fuel efficiency of the generator.
[0017] A method of reducing variations in a power load on a power plant having a generator includes routing power between the generator and a energy storage device during a time when the power load on the power plant is lower than a first level. The energy storage device stores energy provided by the generator. The energy storage device may include at least one ultracapacitor. The energy storage device may include at least one battery. The first level may be based, in part, on a fuel efficiency of the generator. The method may also include routing power between the generator and the power storage device during a time when the power load on the power plant is higher than a second level. The second level may be higher than the first level. The energy storage device may deliver power to the power plant. The second level may be chosen, in part, based on a fuel efficiency of the generator. The method further includes routing power between the generator and a power consuming device during a time when the power load on the power plant is lower than a third level. The third level may be lower than the first level. The third level may be chosen based, in part, on a capacity of the energy storage device.
[0018] A power plant includes means for generating power to meet a power load of the power plant. The power plant also includes means for reducing variation in the power load of the power plant. The means for reducing variation may include means for consuming energy. The variation reducing means may include means for storing energy.
[0019] The foregoing has outlined rather broadly the features and technical advantages of the present disclosure in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the technology of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings.
[0021] FIG. 1 is a block diagram illustrating a conventional DC voltage bus coupling multiple AC voltage generation systems to various loads.
[0022] FIG. 2 is a graph illustrating the operation of a diesel power generator.
[0023] FIG. 3 is a block diagram illustrating power distribution on a conventional power plant.
[0024] FIGS. 4A to 4E are graphs illustrating power consumption in a conventional power plant such as FIG. 3 .
[0025] FIG. 5 is a block diagram illustrating power distribution on an exemplary power plant with power dissipating devices to consume regenerated energy according to one embodiment.
[0026] FIGS. 6A to 6F are graphs illustrating power consumption in an exemplary power plant with resistors to consume regenerated energy according to one embodiment.
[0027] FIG. 7 is a block diagram illustrating power distribution on an exemplary power plant with active power compensation according to one embodiment.
[0028] FIGS. 8A to 8G are graphs illustrating power consumption in an exemplary power plant with active power compensation according to one embodiment.
[0029] FIGS. 9A to 9G are graphs illustrating power consumption in an exemplary power plant with active power compensation and a capacity limited energy storage device according to one embodiment.
[0030] FIG. 10 is a block diagram illustrating an exemplary active power compensation system according to one embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0031] Reducing variation of the load on a generator in a power plant may be accomplished by adding devices that dissipate power during short times when power loads are volatile. In this arrangement, the generator may be able to continue operation at a higher output while the power dissipating devices remove power generated by some loads. Without the power dissipating devices to remove energy generated by the loads, the generators would reduce power output and allow other loads to absorb the regenerated power.
[0032] FIG. 5 is a block diagram illustrating power distribution on an exemplary power plant with power dissipating devices to consume regenerated energy according to one embodiment. A hybrid power plant 500 includes an AC generator 502 coupled to a switchboard 508 through an AC line 506 . The switchboard 508 is coupled to the AC line 506 and an AC line 510 . A power dissipating device 512 is coupled to the AC line 510 . The power dissipating device 512 may represent, for example, shipboard loads. The switchboard 508 is also coupled to an AC-to-DC converter 518 through an AC line 516 . The AC-to-DC converter 518 provides power to a DC line 520 . A light 522 couples to the DC line 520 . Additionally, a DC-to-AC converter 524 is coupled to a power dissipating device 526 and the DC line 520 . The power dissipating device 526 may be a draw works as described above. Additionally, a DC-to-DC converter 532 couples a power dissipating device 534 to the DC line 520 . The power dissipating device 534 may be any device capable of consuming energy. For example, the power dissipating device 534 may be a resistor, variable resistor, water brake, or a combination of the aforementioned devices. The power demand on the AC generator 502 from the loads 512 , 522 , 526 , 534 will now be examined.
[0033] Referring to FIG. 6 the loads at various locations on the hybrid power plant 500 are examined. FIGS. 6A to 6F are graphs illustrating power consumption in an exemplary power plant with resistors to consume regenerated energy according to one embodiment. A line 602 in FIG. 6A indicates power consumption at the power dissipating device 512 . Shipboard loads such as the power dissipating device 512 operate as a constant load over extended periods of time on the power plant. A line 606 in FIG. 6C indicates power consumption at the light 522 . The light 522 operates as a constant load over extended periods of time on the hybrid power plant 500 . A line 604 in FIG. 6B indicates power consumption at the power dissipating device 526 . Draw works such as the power dissipating device 526 have a power load that varies rapidly with time in as small as millisecond intervals. In the case of power dissipating device 526 , the power load is positive at some times and negative at other times. During the positive portion of the line 604 the power dissipating device 526 consumes power; during the negative portion of the line 604 the power dissipating device 526 delivers power to the power plant.
[0034] During a time when the power dissipating device 526 is delivering power to the hybrid power plant 500 the AC generator 502 will reduce power output to accommodate the regenerated power. As described above, the AC generator 502 loses efficiency when its power output is reduced or changes rapidly. Therefore, the power dissipating device 534 may be switched on by the DC-to-DC converter 532 to consume excess power on the DC line 520 . This allows the AC generator 502 to continue operating at a nearly constant power output. A line 608 in FIG. 6D indicates power consumption by the power dissipating device 534 . The line 608 is positive because the power dissipating device 534 is only capable of consuming power. The DC-to-DC converter 532 is switched on at times that it would be advantageous to add additional power consumption to the hybrid power plant 500 . According to one embodiment, the line 608 represents power consumption substantially equal in magnitude to the line 604 during the period of time that the line 604 is negative. Therefore, the power dissipating device 534 consumes power generated by the power dissipating device 526 . The DC-to-DC converter 532 may be switched on for a longer time or shorter time depending on the condition of other loads on the hybrid power plant 500 .
[0035] Total power transferred through the AC-to-DC converter 518 is indicated by a line 610 in FIG. 6E . The line 610 is a summation of the lines 604 , 606 , 608 . Total power delivered by the AC generator 502 is indicated by a line 612 in FIG. 6F . The line 612 is a summation of the lines 610 , 602 . The line 612 indicates the load on the hybrid power plant 500 is confined to a more narrow range than that of the line 410 in FIG. 4E in which no power dissipating device is implemented. For example, the line 612 has a minimum of 1 MW whereas the line 410 has a minimum of 0 MW The addition of the power dissipating device 534 and the DC-to-DC converter 532 limits power output reduction of the AC generator 502 when one of the loads in the hybrid power plant 500 generates power. The most inefficient operating range of the AC generator 502 is at low power output, therefore, efficiency of the AC generator 502 in the hybrid power plant 500 is improved by not operating the AC generator 502 at low power loads.
[0036] The power plant may be further adapted to increase efficiency if the energy generated by loads may, instead of being dissipated, be stored and used at a later time when power demand increases. As a result, an increase in load on the power plant would result in a discharge of the stored energy allowing the AC generator to continue operating at a nearly constant engine power load. A system for storing energy and delivering energy depending on conditions in the power plant is referred to as an active power compensation system.
[0037] FIG. 7 is a block diagram illustrating power distribution on an exemplary power plant with active power compensation according to one embodiment. A hybrid power plant 700 includes a energy storage device 744 coupled to the DC line 520 through a DC-to-DC converter 742 . The energy storage device 744 may be switched on by the DC-to-DC converter 742 when additional power should be delivered to the DC line 520 . The energy storage device 744 may also be switched on at times when excess power is delivered to the DC line 520 such that the energy may be stored by the energy storage device 744 . The energy storage device 744 may be any energy storing device including, but not limited to, spring tension, fuel cells, flywheels, capacitors, variable capacitor, ultracapacitors, batteries, or a combination of the aforementioned devices. In addition to energy storage device 744 , the hybrid power plant 700 may, in one embodiment, also include the power dissipating device 534 coupled to the DC-to-DC converter 532 .
[0038] Turning now to FIG. 8 , the load on the hybrid power plant 700 at various locations will be examined. FIGS. 8A to 8G are graphs illustrating power consumption in an exemplary power plant with active power compensation according to one embodiment. The lines 602 , 604 , 606 of FIGS. 8A , 8 B, and 8 C, respectively, are identical to those in FIG. 6 . A line 809 in FIG. 8E indicates power load of the energy storage device 744 . The line 809 has substantially the same magnitude as the line 604 , but of opposite polarity. The line 809 is a minor image of the line 604 . The energy storage device 744 stores energy during periods of excess power generation and delivers energy during periods of power generation shortage. As a result, variations in power load on the AC generator 502 are reduced. The reduction is a result of the energy storage device 744 consuming power during time that the power dissipating device 526 and delivering that power back to the hybrid power plant 700 . A line 808 in FIG. 8D indicates the power load on the power dissipating device 534 . Power load at the AC-to-DC converter 518 in the hybrid power plant 700 is indicated by a line 810 in FIG. 8F . The line 810 is a summation of the lines 808 , 809 , 606 , 604 and is a substantially constant value. A line 812 in FIG. 8G indicates total power load on the AC generator 502 and is a summation of lines 810 , 602 and is also a nearly constant value.
[0039] Thus, the use of the energy storage device 744 reduces the effects of a varying power load on the AC generator 502 . The energy storage device 744 may adapt to changes in the power load of the power dissipating device 526 and other loads in the hybrid power plant 700 . The nearly constant power load on the AC generator 502 allows for continuous operation in the most efficient operating region of the AC generator 502 . Additionally, the energy storage device 744 increases dynamic performance of the hybrid power plant 700 . The AC generator 502 in response to an increasing power load may not be capable of increasing output quickly enough to match the increasing power load. The energy storage device 744 may have a shorter response time to the increasing power load and deliver additional power while the AC generator increases output to match the power load on hybrid power plant 700 . According to one embodiment, the improved dynamic performance of the hybrid power plant 700 having the energy storage device 744 allows the AC generator to remain at a substantially constant power output.
[0040] The power dissipating device 534 , in one embodiment, is used to consume power when power generation by the power dissipating device 526 exceeds a capacity of the energy storage device 744 . FIGS. 9A to 9G are graphs illustrating power consumption in an exemplary power plant with active power compensation and a capacity limited energy storage device according to one embodiment. The line 909 in FIG. 9E represents power at the energy storage device 744 . According to one embodiment, the energy storage device 744 has an energy capacity of 1 megaJoule. During power consumption of line 604 , the line 909 is negative indicating the energy storage device 744 is providing power. During power generation of the line 604 , the line 909 is positive indicating the energy storage device 944 is storing power. As the energy storage device 744 reaches a maximum energy capacity at time t 2 , the power dissipating device 534 will engage to absorb regenerated power from the load 526 in order to maintain a substantially constant load on the AC generator 502 . The actual energy capacity of the energy storage device 744 may vary from the embodiment demonstrated. The line 908 in FIG. 9D illustrates that during the portion of time that the energy storage device 744 is near capacity, the power dissipating device 534 consumes power. As a result, the summation of the switchboard 508 yields the same power load as in FIG. 8 .
[0041] FIG. 10 is a block diagram illustrating an exemplary active power compensation system according to one embodiment. An active power compensation system 1000 may be employed to store and deliver energy to the hybrid power plant 700 . An input line 1012 is used to connect the active power compensation system to a power plant. The active power compensation system 1000 includes several columns 1034 of power storage devices. Each column 1034 includes energy storage devices 1042 . The energy storage devices 1042 may be, for example, ultracapacitors, capacitors, batteries, or fly wheels. The energy storage devices 1042 are stacked in series to obtain a desired voltage and in columns 1034 to obtain a desired current or optimal energy density. The energy storage devices 1042 are controlled by microcontrollers 1044 to regulate charging and discharging activities. For example, the microcontrollers 1044 may disconnect defective or damaged power storage devices 1042 from the columns 1034 .
[0042] Examples of hybrid power plants for drilling vessels including shipboard loads have been shown in the above embodiments. However, the power plants as disclosed may be adapted for use in a number of other applications. Additionally, the power plants may include AC or DC generators and loads. AC-to-DC, DC-to-AC, and DC-to-DC converters as shown in the figures above may be unidirectional or bidirectional. One of ordinary skill in the art would be capable of substitution, e.g., an AC-to-DC for a DC-to-AC converter, depending upon load configuration and characteristics (i.e., DC load or AC load) of a particular power plant.
[0043] Although the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the present invention, disclosure, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present disclosure. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.
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A hybrid power plant is characterized by a substantially constant load on generators regardless of momentary swings in power load. Short changes in power load are accommodated by DC components such as capacitors, batteries, resistors, or a combination thereof. Resistors are used to consume power when loads in the power plant are generating excess power. Capacitors are used to store and deliver power when the loads in the power plant demand additional power. Reducing rapid changes in power load as seen by the generators allows the generators to operate at higher efficiencies and with reduced emissions. Additionally, power plants employing combinations of generators, loads, and energy storage devices have increased dynamic performance.
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FIELD
[0001] This application relates to differentials, and more specifically to mechanical locking differentials designed to sense wheel speed and automatically lock the device from differentiating rotation.
BACKGROUND
[0002] Existing mechanical locking differentials (M-lockers) are designed to automatically lock the differential when a difference in wheel speed is sensed above a predetermined value. However, the existing design uses friction disks in a wet clutch pack, thus requiring fluid lubrication for engagement. The fluid is subject to degradation and its properties can vary with temperature and degradation.
SUMMARY
[0003] The apparatus disclosed herein overcome the above disadvantages and improves the art by way of a differential which can comprise a first side gear and a second side gear facing the first side gear. A pinion gear set can be between the first side gear and the second side gear. A cam plate comprises a ramped side facing a ramped side of the first side gear. A first lock plate comprises a first side abutting a second side of the cam plate. The first lock plate further comprises a toothed side. A second lock plate comprises a toothed side facing the toothed side of the first lock plate.
[0004] Additional objects and advantages will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the disclosure. The objects and advantages will also be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
[0005] 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 claimed invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a view of the internal components of a differential having the case and ring gear removed.
[0007] FIG. 2 is an example of an engagement mechanism in relation to a cam plate and side gear.
[0008] FIG. 3 is an exploded view of the differential of FIG. 1 .
[0009] FIG. 4A is a perspective view of a first side of a cam plate.
[0010] FIG. 4B is a view of a second side of the cam plate.
[0011] FIG. 5 is a view of a partially assembled differential showing a ramped side of a side gear.
[0012] FIG. 6 is a view of an eared lock plate.
[0013] FIG. 7 is a view of a splined lock plate.
DETAILED DESCRIPTION
[0014] Reference will now be made in detail to the examples which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Directional references such as “left,” “right,” “up,” and “down” are for ease of reference to the figures.
[0015] In an open mode, a differential is configured to allow two wheels on a motor vehicle to operate at different speeds. In a locked mode, the two wheels are locked so that they rotate at the same speed. One torque path, for a front wheel drive (FWD) vehicle, may include torque transfer from an engine to a transmission to a power transfer unit to a drive shaft to a pinion gear to a ring gear around a differential case to a pinion shaft 101 within the differential. As the pinion shaft 101 rotates, affiliated pinion gears 103 and 104 can transfer differentiated or undifferentiated torque to meshing side gears 190 and 110 . The side gears have internal splines 112 and 192 to transfer torque to externally splined drive axles. Torque is then transferred to affiliated wheels. Since this torque path, as well as rear wheel drive (RWD) and all wheel drive (AWD or 4WD) torque paths, are known, the vehicle driveline is not illustrated. The ring gear and differential case are also not illustrated. Despite the specific reference to FWD, RWD, and AWD systems, it is to be understood that the differential may be used in any suitable environment requiring a differential rotation for two shafts.
[0016] A mechanical locking differential (M-locker) uses a mechanical device, as opposed to a solenoid or hydraulic device, to go between the locked and open modes. The mechanical device can comprise, for example, one of those described in U.S. Pat. No. 6,319,166, U.S. Pat. No. 7,438,661, and U.S. Pat. No. 8,167,763, assigned to Eaton Corporation and incorporated by reference herein in their entireties.
[0017] In the example shown in FIGS. 1-3 , the mechanical device comprises an engagement mechanism, which can comprise a shaft having a first end 200 and a second end 203 , both for coupling to the differential case. The shaft may include a shaft gear 201 . End plates 213 and 214 may have flyweights 210 and 211 between them and a flyweight spring 212 may bias the flyweights 210 and 211 . At least end plate 214 engages with a cone clutch 215 . The shaft may rotate with the cam plate 120 via the shaft gear teeth 201 in mesh with rim teeth 408 . When the shaft rotates due to differential action and the rotation speed is above a predetermined value, the flyweights 210 and 211 spin up. The centrifugal force must be enough to overcome the biasing force of the flyweight spring 212 . The rotation must also be sufficient to overcome the grip between the end plate 214 and the cone clutch 215 .
[0018] In order to lock the differential (exit open mode), at least one of the flyweights 210 or 211 must engage with the pawl 222 on a lockout mechanism on the second shaft. The second shaft has a first end 220 and a second end 221 , both for coupling with the differential case. If the vehicle travels over a predetermined speed, the centrifugal force on the lockout causes a counterweight 223 to pull the pawl 222 out of the available range of the flyweights 210 and 211 and the differential cannot enter the locked mode. It can only operate in the open mode. The described example is not meant to limit the mechanical device for locking or unlocking the differential described herein. Other mechanical devices are used in the alternative with the differential described herein.
[0019] FIGS. 1 and 3 show the engagement mechanism in an un-activated state, such as when the differential is stationary, or when operating under a predetermined differential speed such as below 100 RPMs. The flyweights 210 and 211 are biased in a closed position.
[0020] In FIG. 2 , the end plate 214 is absent for clarity. The flyweights 210 and 211 have spun-up and the pawl 222 has caught against a step in flyweight 211 . This locks the first shaft from rotation. The shaft gears 201 are geared to rim teeth 408 of the cam plate 120 . The locking creates sufficient force to move the cam plate 120 . Further discussion of engagement mechanisms and their operation can be understood from examples such as U.S. Pat. No. 6,319,166, U.S. Pat. No. 7,438,661, and U.S. Pat. No. 8,167,763.
[0021] As shown in FIGS. 4A and 4B , the cam plate 120 has ramps 402 and valleys 403 . The ramps 402 comprise upward ramps 405 leading to crests 404 . The valleys 403 comprise downward ramps 406 leading to ravines 407 . The ramps 402 and valleys 403 are shown with stepwise transitions, and the cam plate 120 can comprise more or fewer stepwise transitions, or the cam plate 120 can comprise smooth transitions between crests 404 and ravines 407 such as by having a single slope therebetween or by having curves therebetween. Also, while five crests 404 and five ravines 407 are shown, more or fewer can be used in practice.
[0022] Also shown in FIG. 4A are detents 401 . While three detents 401 are shown, more or fewer can be used in practice. The detents 401 mate with corresponding holes 115 in the left side gear 110 . The detents 401 and holes 115 are sized so that the detents 401 leave the holes 115 when the above locking of the flyweight 210 or 211 against the pawl 222 creates sufficient force to move the cam plate 120 . The ramps 402 then slide against corresponding side gear ramps 116 . That is, in the open mode, crests 404 rest in side gear ravines 118 , and side gear crests 117 rest in ravines 407 . In the locked mode, the crests “ramp-up” and slide out of the ravines and against opposed ramps as the detents 401 leave the holes 115 . When the differential exits locked mode, the crests “ramp-down” and slide back in to corresponding ravines while the detents 401 re-enter the holes 115 .
[0023] Cam plate action against the side gear, as well as cam plate and side gear configurations, may be further understood from examples such as U.S. Pat. Nos. 3,606,803, 5,484,347, 6,319,166, RE 28,004, and U.S. Pat. No. 3,831,462, incorporated herein by reference in their entirety.
[0024] The left side gear 110 is braced against the pinion gears 103 and 104 via meshing engagement of side gear teeth 111 with pinion gear teeth. Any motion of the left side gear 110 as the cam plate 120 “ramps-up” can be passed to the spring-loaded lock plates.
[0025] In the example shown, no reaction block is used to pass force from the left side gear 110 to the right side gear 190 . Therefore, the “ramp-up” of the cam plate does not also cause compression of the clutch pack 180 . The clutch pack 180 can be operated to enable limited slip, or the clutch pack 180 can be eliminated.
[0026] The forces created as the cam plate 120 moves against the left side gear 110 can be transferred to the first lock plate 140 and then to the second lock plate 150 , with some absorption by wave spring 130 . Such an arrangement enables the elimination of all wet clutch packs and the use of a reaction block, thus simplifying the differential, reducing weight, and enabling reduction of size. The right side gear 190 can abut the differential case similar to the above-incorporated RE 28,0004 and U.S. Pat. No. 3,831,462 or can be used with other designs having no friction discs adjacent the right side gear.
[0027] As the cam plate 120 “ramps-up,” first lock plate 140 moves axially with its lock plate inner splines 702 along left side gear outer splines 114 . This compresses a wave spring 130 and first lock plate teeth 704 lock against second lock plate teeth 604 . Each first lock plate tooth 704 is separated by a lock plate groove 703 . Each second lock plate tooth 604 is likewise separated by a plate groove 603 .
[0028] The wave spring 130 seats against wave spring seat 601 . The wave spring 130 biases the first lock plate 140 away from the second lock plate 150 . As the wave spring 130 pushes against first lock plate 140 , first lock plate 140 pushes against cam plate 120 . This biases the detents 401 in the holes 115 .
[0029] In embodiments where the second lock plate 150 comprises ears 602 , optional ear guards 151 can be included. The ears 602 and optional ear guards 151 engage with corresponding grooves in the differential case so as to lock the second lock plate 150 from rotating with respect to the case. The first lock plate 140 is forced to rotate with the left side gear 110 via the mating of inner splines 702 with side gear outer splines 114 .
[0030] An optional coupling ring 160 or thrust washer abuts the second lock plate 150 , and an optional coupling ring or thrust washer 170 abuts the side gear 110 and differential case.
[0031] When the first lock plate teeth 704 lock against second lock plate teeth 604 , the left side gear 110 is locked to rotate with the differential case. The pinion shaft 101 , locked to the differential case via optional lock pin 102 , must also rotate with the housing. Affiliated pinion gears 103 and 104 are locked to rotate with the left side gear 110 via the meshing of side gear teeth 111 with the pinion gear teeth. Thus, the meshed side gear teeth 191 of right side gear 190 must rotate at the same rate as the left side gear 110 . This gear coupling is in addition to the coupling between the right side gear 190 and the differential case, described below.
[0032] Right side gear 190 further includes inner spline 192 for coupling to an axle shaft and an outer spline 194 for coupling to clutch pack 180 . The clutch pack 180 can comprise plates with ears 184 and friction discs with splines 181 . The disc splines 181 couple to the right side gear outer spline 194 . Optional ear guards 182 surround the ears 184 , which mate with corresponding grooves in the differential case. A coupling ring 183 or thrust washer is between the differential case and the clutch pack 180 .
[0033] Because the ears 184 are coupled to the differential case, when the affiliated friction discs are frictionally engaged with the eared plates, the right side gear 190 must rotate, via the spline connection, with the differential case. The friction engagement of the clutch pack 180 can be facilitated by the selection of an appropriate viscosity lubricating fluid. The clutch pack 180 can be used to provide limited slip capability to the differential, or as an alternative the clutch pack 180 can be eliminated.
[0034] The first lock plate 140 comprises radially extending teeth sized and spaced to mate with radially extending teeth of the second lock plate 150 . In an open mode, the space between first lock plate 140 and second lock plate 150 is sized so that the crests 404 of the cam plate 120 rest in ravines 118 of the left side gear. The spacing is selected so that the crests 404 of the camp plate 120 do not pass crests 117 of the left side gear when the cam plate 120 locks. The design enables positive locking such that the differential operates either fully locked or in open mode.
[0035] Because of the simplified design, the differential can lock in both directions. That is, the differential can lock no matter which direction the side gears are spinning so long as one of the flyweights 210 or 211 can catch the pawl 222 .
[0036] An advantage of using the two lock plates is the enhanced reliability offered by the tooth-to-tooth contact. That is, the dog-style coupling is more reliable than the wet friction disc contact, resulting in reduced slippage. In addition, the lock plates can be designed to take up less axial space than friction discs, thus further reducing the size of the differential. The lock plate engagement and use generates less heat than the friction discs, leading to less fluid degradation. And, the elimination of the friction discs reduces the machining to the differential case, leading to less costly manufacture.
[0037] Other implementations will be apparent to those skilled in the art from consideration of the specification and practice of the examples disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
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A differential comprises a first side gear and a second side gear facing the first side gear. A pinion gear set can be between the first side gear and the second side gear. A cam plate comprises a ramped side facing a ramped side of the first side gear. A first lock plate comprises a first side abutting a second side of the cam plate. The first lock plate further comprises a toothed side. A second lock plate comprises a toothed side facing the toothed side of the first lock plate.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Patent Application No. 60/468,243, entitled Lossless Image Data Hiding Through Histogram Modification Implemented in Spatial Domain, filed May 6, 2003, and U.S. Provisional Patent Application No. 60/549,424, entitled Reversible Data Hiding, filed Mar. 2, 2004; the entire disclosures of which are hereby incorporated by reference.
BACKGROUND
This application is directed to methods and apparatus for data hiding in an image and, more particularly, to lossless and reversible data hiding in the spatial domain.
In the field of data hiding, pieces of information represented by the data are hidden in the cover media (e.g., a pixel image). In other words, the data hiding process links two sets of data, a set of the embedded data and another set of the cover media data. The relationship between these two sets of data defines different applications. For instance in covert communications, the hidden data are irrelevant to the cover media. In authentication, however, the embedded data are closely related to the cover media. In these types of applications, invisibility of hidden data is an important requirement. In most cases, the cover media will experience some distortion due to data hiding and cannot be inverted back to the original media. Indeed, some permanent distortion occurs to the cover media even after the hidden data have been extracted.
In some applications, such as medical diagnosis and law enforcement, it is desirable to reverse the marked media back to the original cover media after the hidden data are retrieved for consideration. The marking techniques satisfying this requirement are referred to as reversible, lossless, distortion-free, or invertible data hiding techniques. Reversible data hiding links two sets of data in such a way that the cover media can be losslessly recovered after the hidden data have been extracted. This provides an additional avenue of handling the two different sets of data.
Many of the existing data hiding techniques are not reversible. For instance, widely utilized spread-spectrum based data hiding methods have been disclosed in the following publications: J. Cox, J. Kilian, T. Leighton, and T. Shamoon, “Secure Spread Spectrum Watermarking for Multimedia,” IEEE Trans. on Image Processing, Vol. 6, No. 12, pp. 1673-1687 (December 1997); and J. Huang and Y. Q. Shi, “An Adaptive Image Watermarking Scheme Based on Visual Masking,” Electronics letters, 34(8): 748-750 (1998). These techniques, however, are not invertible owing to truncation (for the purpose to prevent over/underflow) error, and round-off error.
Another well-known least significant bit-plane (LSB) approach is discussed in J. Irvine and D. Harle, Data Communications and Networks: An Engineering Approach, West Sussex, England: John Wiley & Sons, Ltd. (2002). This approach is not lossless owing to bit-replacement without “memory.”
Another category of data hiding techniques is quantization-index-modulation (QIM), which is discussed in detail in B. Chen and G. W. Wornell, “Quantization Index Modulation: A Class of Provably Good Methods for Digital Watermarking and Information Embedding,” IEEE Transactions on Information Theory, Vol. 47, No. 4, pp. 1423-1443 (May 2001). This technique is not distortion-free owing to the quantization error.
Although most of the current digital watermarking algorithms are not lossless, some recent marking techniques have been reported as being lossless. For example, two methods carried out in the image spatial domain purport to be lossless. The details of these methods may be found in U.S. Pat. No. 6,278,791 (the entire disclosure of which is hereby incorporated by reference) and J. Fridrich, M. Goljan and R. Du, “Invertible Authentication,” Proc. SPIE, Security and Watermarking of Multimedia Contents, pp. 197-208, San Jose, Calif., (January. 2001). In the '791 patent, the marking is carried out in the spatial domain. The method uses modulo 256 addition to embed a hash value of an original image for authentication. The technique is reversible because of the modulo 256 addition; however, the modulo 256 addition also may produce some annoying salt-and-pepper noise due to grayscale flipping over between 0 and 255 in either direction. The Fridrich approach also operates in the spatial domain and losslessly compresses some selected bit-plane(s) to leave space for data embedding. Since bookkeeping data are also embedded as overhead, the method is reversible. The amount of hidden data, however, is quite limited because the bias between binary bits, 0s and 1s (the tendecy the have more 0's or more 1's in the data) is not significant in the several lower levels that include the least significant bit-plane (LSB) in the spatial domain. The lack of bias was probably not a problem in the Fridrich approach because it is directed towards data authentication instead of data embedding.
A purportedly lossless marking technique has also been developed in the transform domain, as is discussed in detail in B. Macq and F. Deweyand, “Trusted Headers For Medical Images,” DFG VIII-D II Watermarking Workshop, Erlangen, Germany, (October. 1999). This reversible marking technique was developed in the transform domain and is based on a lossless multi-resolution transform and the patchwork theory. It also uses modulo 256 addition. Since each block, say, an 8×8 block can only be used to embed one bit, the amount of hidden data that may be achieved is quite limited. More details concerning the patchwork theory may be found in W. Bender, D. Gruhl, N. Morimoto and A. Lu, “Techniques for Data Hiding,” IBM Systems Journal, Vol. 35, No. 3-4, pp. 313-336 (1996).
Yet another marking technique is discussed in detail in C. De Vleeschouwer, J. F. Delaigle and B. Macq, “Circular Interpretation on Histogram for Reversible Watermarking,” IEEE International Multimedia Signal Processing Workshop, France, pp. 345-350 (October 2001). The capacity of this method, which is based on the idea of patchwork and modulo 256 addition, is also limited except that it is expected to exhibit some robustness against high quality JPEG compression.
A reversible marking technique that is suitable for a large amount of hidden data is discussed in detail in M. Goljan, J. Fridrich, and R. Du, “Distortion-free Data Embedding,” Proceedings of 4 th Information Hiding Workshop, pp. 27-41, Pittsburgh, Pa., (April 2001), also in U.S. patent application Ser. No.: 2003/0081809 (the entire disclosure of which is hereby incorporated by reference). The amount of hidden data achievable by this technique, however, is still not large enough for many applications, such as medical applications. Indeed, the pay-load ranges from 3,000 bits to 24,000 bits for a 512×512×8 grayscale image, i.e., from 0.011 bits per pixel (bpp) to 0.092 bpp as the PSNR of the marked image versus the original image is 39 dB. This technique first segments an image into non-overlapped blocks, and then introduces a discriminating function to classify these blocks into three groups: R(egular), S(ingular) and U(nusable). It further introduces a flipping operation, which can convert an R block to an S block and vice versa. A U block remains intact after the flipping operation. By assigning, say, a binary 1 to an R block and a binary 0 to an S block, all R and S blocks are scanned in a chosen sequential order, resulting in a binary sequence. This binary sequence is losslessly compressed and the compressed sequence is saved as overhead for late reconstruction of the original image. In data embedding, the R and S blocks are scanned once again and the flipping operation is applied whenever necessary to make the changed R and S block sequence coincident with the to-be-embedded data (another binary 0 and 1 bit stream) followed by the overhead data. While successful in reversible data hiding, the payload is still not large enough for some applications, as indicated above. Another problem with the method is that when the embedding strength increases in order to increase payload, the visual quality drops severely due to annoying artifacts.
To increase payload dramatically, a new lossless data hiding technique based on integer wavelet transform is discussed in detail in U.S. patent application Ser. No.: 60/527,900, filed Dec. 5, 2003, entitled Methods and Apparatus for Lossless Data Hiding, the entire disclosure of which is hereby incorporated by reference. Because of the superior decorrelation capability of the wavelet transform, the selected bit-plane compression in high frequency subbands creates more space for data hiding, resulting in a higher payload than that in the method described in U.S. patent application Ser. No.: 2003/0081809. Specifically, for a 512×512×8 image, 5,000 bits to 80,000 bits can be embedded, i.e., the payload is from 0.019 bpp to 0.31 bpp while the PSNR of the marked image versus the original image is guaranteed above 48 dB. In addition, the integer wavelet transform, a second generation wavelet transform, helps to avoid round-off error. To achieve reversible data hiding, a histogram modification is applied during pre-processing to prevent over/underflow. This histogram modification causes, however, a lower PSNR of the marked image versus the original image though there are no annoying artifacts.
It is noted that reversible data hiding has attracted more and more attention recently and more and more algorithms are being developed. Another example is the technique reported in M. U. Celik, G. Sharma, A. M. Tekalp and E. Saber, “Reversible Data Hiding,” Proceedings of IEEE 2002 International Conference on Image Processing, Vol. 2, pp. 157-160 (September 2002). Still a further example is the technique reported in J. Tian, “Reversible Data Embedding Using a Difference Expansion,” IEEE Transactions on Circuits and Systems for Video Technology, vol. 13, no. 8, pp. 890-896, August 2003.
Accordingly, there are needs in the art for new methods and apparatus for achieving lossless marking that can embed a relatively large amount of data, while keeping a high visual quality of the marked images.
SUMMARY OF THE INVENTION
In accordance with one or more aspects of the present invention, a reversible data embedding technique is contemplated that may embed a relatively large amount of data (e.g., about 5K to 80K bits for a 512×512×8 grayscale image, equivalent to a payload from 0.019 bbp to 0.31 bpp) while keeping a very high visual quality (e.g., the PSNR of the marked image versus original image is at least 48 dB). The approach utilizes a zero or minimum point and a peak point of a histogram of the image to be marked and slightly modifies the pixel value to embed the data. The technique can be applied to virtually all types of images.
In accordance with one or more further aspects of the present invention, provides for methods and apparatus that are capable of: producing a histogram from a pixel domain image, the histogram establishing a relationship of possible pixel values versus respective aggregate numbers of pixels of the pixel domain image having such pixel values; modifying some of the pixel values of the pixel domain image to shift a portion of the histogram such that there no longer exists an aggregate number of pixels having a first possible pixel value; and modifying some of the pixel values of the pixel domain image such that an aggregate number of pixels exist having the first possible pixel value, where the aggregate number of pixels is a function of the data to be hidden.
In accordance with one or more further aspects of the present invention, the methods and apparatus for marking images described thus far and/or described later in this document, may be achieved utilizing suitable hardware, such as that shown in the drawings hereinbelow. Such hardware may be implemented utilizing any of the known technologies, such as standard digital circuitry, analog circuitry, any of the known processors that are operable to execute software and/or firmware programs, one or more programmable digital devices or systems, such as programmable read only memories (PROMs), programmable array logic devices (PALs), any combination of the above, etc. Further, the methods of the present invention may be embodied in a software program that may be stored on any of the known or hereinafter developed media.
Other aspects, features and advantages of the present invention will become apparent to those skilled in the art when the description herein is taken in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
For the purposes of illustration, there are forms shown in the drawings that are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
FIG. 1 is a flow chart of a data embedding (or encoding) method and apparatus for embedding hidden data in a pixel domain image in accordance with one or more aspects of the present invention;
FIG. 2 is an illustration of the original pixel domain image of FIG. 2 in which no hidden data have been embedded;
FIG. 3 is an illustration of an unmodified histogram of an original pixel domain image in accordance with one or more aspects of the present invention;
FIG. 4 is an illustration of exemplary data to be hidden in an original pixel domain image in accordance with one or more aspects of the present invention;
FIG. 5 is an illustration of a modified histogram of the original pixel domain image of FIG. 3 in accordance with one or more aspects of the present invention;
FIG. 6 is an illustration of the pixel domain image of FIG. 2 in which hidden data have been embedded in accordance with the modified histogram of FIG. 5 ;
FIG. 7 is an illustration of an unmodified histogram of a different original pixel domain image in accordance with one or more aspects of the present invention;
FIG. 8 is a block diagram of a data extraction (or decoding) method and apparatus for extracting embedded hidden data from the pixel domain image in accordance with one or more aspects of the present invention;
FIG. 9 is an illustration of a pixel domain image in which the hidden data of FIG. 4 have not been embedded;
FIG. 10 is an illustration of an unmodified histogram of the pixel domain image of FIG. 9 in accordance with one or more aspects of the present invention;
FIG. 11 is an illustration of a modified histogram of the pixel domain image of FIG. 9 in accordance with one or more aspects of the present invention;
FIG. 12 is an illustration of the pixel domain image of FIG. 9 in which the hidden data of FIG. 8 have been embedded in accordance with one or more aspects of the present invention;
FIG. 13 is an illustration of test results indicating peak signal to noise ratios (PSNR) and corresponding hidden data payload sizes for several test images in which hidden data have been embedded in accordance with one or more aspects of the present invention; and
FIG. 14 is an illustration of comparisons between hidden data payload sizes for several embedding techniques, including that in accordance with one or more aspects of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In general, the present invention is directed to methods and apparatus for hiding (embedding) a relatively large amount of data in an image, where the original image may be recovered without any distortion from the marked image after the hidden data have been extracted. FIG. 1 is a flow diagram illustrating process steps that may be carried out to hide data in an image in accordance with one or more aspects of the present invention. It is noted that although FIG. 1 is a flow diagram of a preferred method, it may also enable apparatus for carrying out the actions of the method. Indeed, the disclosed method for marking images may be achieved utilizing suitable hardware, such as digital circuitry, analog circuitry, any of the known processors that are operable to execute software and/or firmware programs, one or more programmable digital devices or systems, such as programmable read only memories (PROMs), programmable array logic devices (PALs), any combination of the above, etc. Further, the present invention may be embodied in a software program that may be stored on any of the known or hereinafter developed media.
The process flow of FIG. 1 starts with obtaining an original, pixel domain (or spatial domain) image (action 100 ). By way of example the well known Lena image of FIG. 2 may be utilized, which a 512×512×8 gray scale image. Once an image is obtained, a histogram of the image is produced (action 102 ). The histogram establishes a relationship of possible pixel values versus respective aggregate numbers of pixels of the pixel domain image having such pixel values. By way of example, a histogram may be a collection (usually a graphical representation) of the gray scale values contained in an image. Alternatively, a histogram may be a collection of color values of an image. As illustrated in FIG. 3 , one embodiment of a histogram for the Lena image of FIG. 2 may be a collection of the gray scale values arranged in a Cartesian coordinate system, e.g., with the gray scale (0-255) along an ordinate axis and the aggregate number of pixel values having a given gray scale along the abscissa axis. In this example, the gray scale value of 0 is black and the gray scale value of 255 is white.
Next, the histogram is analyzed to determine whether any zero points exist, i.e., where no pixel of the image has the corresponding gray scale value (action 114 ). If the result of the determination is in the affirmative, then the process flow advances to action 116 . If the result of the determination at action 114 is in the negative, then the process flow advances to action 122 (which will be discussed later in this description). In the histogram of FIG. 3 , a number of zero points exist, such as at the gray scale value of 255, where no pixel assumes that gray scale value. Thus, the process flow advances to action 116 , where the histogram is shifted. To shift the histogram, a peak point is located, i.e., a gray scale value having a maximum number of pixel values. By way of example, a peak point exists at gray scale value 154. Next, the image is scanned in a defined order, e.g., row-by-row, from top to bottom, or column-by-column, from left to right, etc, . and certain pixel values are augmented by an amount (a shifting value) such that the gray scale values between the zero point and the peak point of the histogram are shifted.
The number and the direction of the shift will depend on the shifting value. For example, a shifting value of +1 added to all pixel values in the image above a selected value will shift the histogram to the right by one gray scale value. If the shifting value is +2, the histogram will be shifted to the right by two gray scale values, etc. On the other hand, a shifting value of −1 added to all pixel values in the image below a selected value will shift the histogram to the left by one gray scale value. If the shifting value is −2, the histogram will be shifted to the left by two gray scale values, etc.
The direction of the shift is preferably “two way” in that it is dependent on whether the gray scale value of the zero point is greater than or less than that of the peak point. For example, if the gray scale value of the zero point is greater than that of the peak point, then the shifting value is preferably a positive value (assuming the conventions discussed thus far), such as +1. This results in the histogram being shifted to the right by one place and opening up a gray scale value for which there are no associated pixel values. With reference to the Lena image of FIG. 2 and the histogram of FIG. 3 discussed above, the gray scale value of the zero point (255) is greater than that of the peak point (154). Thus, the gray scale values between the peak point and the zero point (non-inclusive) are shifted to the right by adding the shifting value (e.g., +1) to all of the pixel values of the histogram from gray scale value 155 to gray scale value 254. This leaves “empty” the gray scale value 155 of the histogram. The gray scale value of 155 may be considered an “embedded point.”
On the other hand, if the gray scale value of the zero point is less than that of the peak point, then the shifting value is preferably a negative value (assuming the conventions discussed thus far), such as −1. This results in the histogram being shifted to the left by one place and opening up a gray scale value for which there are no associated pixel values. With reference to the Lena image of FIG. 2 and the histogram of FIG. 3 discussed above, assume a different gray scale value of the zero point of 20, which is less than that of the peak point ( 154 ). Thus, the gray scale values between the peak point and the zero point (non-inclusive) are shifted to the left by adding the shifting value (e.g., −1) to all of the pixel values of the histogram from gray scale value 153 to gray scale value 20. This leaves “empty” the gray scale value 153 of the histogram.
After the histogram is shifted, the process flow advances to action 118 , where an embedding process is carried out. In this regard, the original image is again scanned (preferably in the same defined order in the shifting action 116 ). It is noted that although this scan need not be in the same defined order as in the shifting process, whatever scanning approach is employed will result in a particular order in which the peak points of the image are encountered. As this order should be reproducible during decoding, it is preferred that the scanning definition is consistent during the shifting action 116 and the embedding action 118 . During the scan, when a pixel having a gray scale value of 154 is encountered, the data sequence to be embedded is analyzed. In particular, if the next bit of the data to be embedded in the sequence is “true,” then the encountered pixel value of the image is augmented by the shifting value (e.g., +1 if the shift were to the right). It is noted that a true bit may be a binary 1 (making the false bit a binary 0 by implication), or the true bit may be a binary 0 (making the false bit a binary 1). Irrespective of the true/false convention, if the next bit of the data to be embedded in the sequence is false, then the encountered pixel value of the image is not augmented. This fills the “empty” gray scale value(s) of the histogram with pixel values taken from the peak point gray scale value.
This process of scanning the image for successive pixels having peak point gray scale values continues until all of the bits of the data to be embedded are encoded into the image. Reference is now made to FIG. 4 , which is an example of data that may be hidden in the original pixel image in accordance with the process discussed above. The NJIT data of FIG. 4 is characterized by a binary sequence of 15,903 bits. An example of the resultant modified histogram for the Lena image of FIG. 2 (assuming use of the hidden of FIG. 4 ) is shown in FIG. 5 , and the resultant modified pixel image is shown in FIG. 6 .
It is noted that the gray scale value of the zero point and the peak point are treated as side information that needs to be transmitted to the receiving side for data retrieval.
It is noted that the objective of finding the peak point in the unmodified histogram is to maximize the embedding capacity of the process. Indeed, the capacity of the embedding process is equal to the maximum number of pixels associated with the peak point because each bit of the data to be embedded is associated with a respective one of the pixels of the peak gray scale value. While use of the peak point is preferred for the above reason, it is not a requirement to use the peak point to practice the invention. Indeed, if maximum data hiding capacity is not desired, then some other grey scale value (call it a “high point”) may be used in place of the peak point.
Similarly, while use of the zero point is preferred, it is not a requirement to use the zero point to practice the invention. Depending on the original pixel image, there may not be any zero point, such as the image associated with the unmodified histogram of FIG. 7 . This is the case where the result of the determination of action 114 ( FIG. 1 ) is negative. Irrespective of whether there is or is not a zero point in the histogram, some other grey scale value (call it a “low point”) may be used in place of the zero point (action 122 ). Preferably, if there is not zero point, the low point is a minimum point. For instance, in the histogram shown of FIG. 7 , the gray scale value 7 is associated with only 23 pixels. This number of 23 is the minimum number since any other gray scale value is associated with more than 23 pixels. The gray scale value and the coordinates of pixels associated with the minimum point are recorded as overhead data, which may be included in the embedded data. In other respects, the minimum point may be used in the same way as the zero point discussed above (124).
It is considered an aspect of the invention to further increase the payload by employing multiple pairs of zero (or low) points and peak (or high) points. This scales the complexity of the algorithm. The scope of the experimentation performed thus far, however, has been limited to at most two pairs of zero points and peak points. For instance, an experiment involving the Lena image of FIG. 2 was conducted using two pairs of peak and zero points in order to achieve a payload of 5,460 bits in the 512×512×8, equivalent to 0.021 bpp as the PSNR is equal to 48.2 dB.
Reference is now made to FIG. 8 , which is a flow diagram illustrating process steps that may be carried out to extract hidden data from an image in accordance with one or more further aspects of the present invention. It is noted that although FIG. 8 is a flow diagram of a preferred method, it may also enable apparatus for carrying out the actions of the method. Indeed, the disclosed method for extracting hidden data may be achieved utilizing suitable hardware, such as digital circuitry, analog circuitry, any of the known processors that are operable to execute software and/or firmware programs, one or more programmable digital devices or systems, such as programmable read only memories (PROMs), programmable array logic devices (PALs), any combination of the above, etc. Further, the present invention may be embodied in a software program that may be stored on any of the known or hereinafter developed media.
As shown in FIG. 8 , the marked image, such as the marked Lena image of FIG. 6 is received at the decoder. The key and side information including the gray scale value of the zero point (255) and the peak point (154) were transmitted to the decoder for data extraction. The data extraction process produces both the hidden (extracted) data and the recovered original data, such as the Lena image of FIG. 2 . The data extraction process (which for simplicity involves only one zero point and peak point pair) is as follows: The marked image is scanned using the same or equivalent definition as in the embedding process ( 118 of FIG. 1 ). When a gray scale value associated with the maximum point is encountered, e.g., 154, then a “false” value is assigned to the extracted data sequence. When a gray scale value associated with the “embedded point” is encountered, e.g., 155, then a “true” value is assigned to the extracted data sequence. In this way, the hidden data are extracted from the marked image.
Next, the marked image is scanned again using the same or equivalent definition as in the embedding process. When a pixel is encountered that has a gray scale value between the peak point (excluding the peak point) and the zero point (including the zero point), then the gray scale value of such pixel is augmented by an equal but opposite amount as the shifting value. For example, in the example above, the peak point was 255, the zero point was 154, and the shifting value was +1. Thus, when a pixel is encountered that has a gray scale value between 155 (including 155) and the zero point 255, then the gray scale value of such pixel is augmented by −1. In this way, the original image can be recovered without any distortion.
It is desirable to achieve high PSNR (peak signal to noise ratio) in the marked image. In the experimentation that has been conducted thus far, the PSNRs of the marked images have all been above 48 dB. This can be proved as follows: It is noted from the embedding algorithm that the pixels whose gray scale value is between the zero point and the peak point may be augmented by +/−1. Therefore, in the worst case, all pixels of the image will be added or subtracted by 1, implying that the mean square of errors is at most equal to one, i.e., MSE =1. Thus, the PSNR of a marked image versus the original image is bounded by 48.13 dB. That is, PSNR=10×log 10 (255×255/MSE)=48.13 dB. The conclusion that the lower bound of the PSNR of a marked image is 48.13 dB has been validated by numerous experiments and is believed to be much higher than all reversible data hiding techniques of the published prior art.
The proposed reversible data hiding algorithm has been applied to many typical grayscale images and medical images, and has demonstrated its universal capability. For example, the well known “Airplane” image (512×512×8) of FIG. 9 , having a histogram shown in FIG. 10 was modified to include the hidden data of FIG. 4 (a binary sequence of 15,903 bits). FIGS. 11 and 12 illustrate the modified histogram and marked Airplane image, respectively. The gray scale values of two zero points are 0 and 255, respectively, and the gray scale values of two peak points are 210 and 211, respectively. The numbers of pixels associated with these two peak points are 8,016 and 8,155, respectively. Hence, the capacity is 8,016+8,155=16,171 bits.
FIG. 13 is a table illustrating further test results indicating peak signal to noise ratios (PSNR) and corresponding hidden data payload sizes for several test images in which hidden data have been embedded in accordance with one or more aspects of the present invention. FIG. 14 is an illustration of comparisons between hidden data payload sizes for several embedding techniques, including that in accordance with one or more aspects of the present invention.
The reversible data hiding technique of the present invention is able to embed about 5k-80k bits into a 512×512×8 grayscale image while keeping the PSNR constantly above 48 dB. Thus, the performance of the invention is better than most existing reversible data hiding algorithms. The techniques of the present invention may be applied to virtually all types of images and may be deployed for a wide range of applications in areas such as medical and law enforcement. In fact, it has been successfully applied to more than 1000 images in CorelDraw image database. Advantageously, various aspects of the present invention permit the hiding (embedding) of a relatively large amount of data in an image, where the original image may be recovered without distortion from the marked image after the hidden data have been extracted.
Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.
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Methods and apparatus are provided for encoding a pixel domain image with hidden data by modifying the histogram of the pixel domain image to make space for such hidden data.
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TECHNICAL FIELD
This invention relates to a chimney cleaning apparatus suspended from a cable in a chimney flue and moved therethrough.
BACKGROUND ART
It is well known in the art of chimney cleaning to suspend a cleaning apparatus in a chimney flue and move the apparatus therethrough in attempts to remove the debris and soot buildup from the inner flue surface. One example of a typical chimney cleaning apparatus is shown in the U.S. Pat. No. 1,837,931 to Walborhl, issued Dec. 22, 1931. The Walborhl patent discloses a chimney apparatus assembly including an eye 7 connected to a weight 15 by a length of chain 17. Slideable along the chain 17, between the eye 7 and the weight 15, is disposed a tubular body 3 supporting a plurality of radially extending wire bristles By repeatedly raising and dropping the chimney cleaning apparatus, the bristles 1 are "hammered" through the chimney flue.
The prior art chimney cleaning apparatus are deficient in that they incorporate yieldable bristles to scrape against the chimney flue for removing the debris. When large debris or particularly "gummy" soot buildup is encountered, the prior art chimney cleaning apparatus bristles deflect around the obstruction and thus do not completely clean the inside of the chimney flue. This is particularly dangerous with the ever present threat of a chimney fire.
SUMMARY OF INVENTION AND ADVANTAGES
The subject invention provides an apparatus for cleaning debris from the inner surface of a chimney comprising a scrapping plate and a support means. The scraping plate has a periphery for conforming to the cross-sectional shape of the inside flue of the chimney. The support means supports the scraping plate in a transverse orientation, relative to the longitudinal axis of the chimney flue, while moving the scraping plate through the chimney flue. The chimney cleaning apparatus of this invention is characterized by providing a scraping plate which is inflexible, for unyieldingly scraping the inside surface of the chimney flue during movement therethrough.
The scraping plate of the subject invention is a rigid member which will not deflect around chimney flue debris or "gummy" soot buildup, thereby completely cleaning the inside surface of a chimney flue. Additionally, the subject invention is easily and inexpensively manufactured from readily available materials, and can be operated by a single person.
FIGURES IN THE DRAWINGS
Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
FIG. 1 is a perspective view of the preferred embodiment of the subject invention;
FIG. 2 is a side view of the subject invention disposed in a chimney flue during one phase of operation;
FIG. 3 is a side view of the subject invention disposed in a chimney flue in another phase of operation; and
FIG. 4 is a side view of the subject invention disposed in a chimney flue in yet another phase of operation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
An apparatus for cleaning debris from the inner surface of a chimney is generally shown at 10 in FIGS. 1 through 4. The subject apparatus 10 comprises a scraping plate, generally indicated at 12, and a support means, generally indicated at 14.
The scraping plate 12 has a periphery for conforming to the cross-sectional shape of the inside flue 16 of a chimney. As shown in FIG. 1, the peripheral shape of the scraping plate 12 is rectangular, as is the cross-sectional shape of the majority of chimney flues 16: however, the geometric configuration will conform to the cross-section of the chimney flue, which may be polygonal, circular, etc. The support means 14 supports the scraping plate 12 in a transverse orientation relative to the longitudinal axis of the chimney flue 16, while moving the scraping plate through the chimney flue 16. In other words, the support means 14 supports the scraping plate 12 in a perfectly transverse, or horizontal, orientation in the chimney flue 16. If the scraping plate 12 does not remain in a perfectly transverse orientation in the chimney flue 16, the peripheral edges of the scraping plate 12 will not contact the entire inner surface of the flue 16, thereby ineffectively cleaning the built-up debris.
The subject apparatus 10 is characterized by the scraping plate 12 being inflexible for unyielding scraping the inside surface of the chimney flue 16 during movement therethrough. That is to say, the scraping plate 12 is a rigid member which will not deflect as it scrapes the inside surface of the chimney flue 16. By providing a rigid scraping plate 12, and by supporting the scraping plate 12 in a perfectly transverse orientation in the chimney flue 16, the debris and soot buildup in the chimney flue 16 is completely dislodged.
As shown in FIGS. 2 through 4, the scraping plate 12 is slideable along the support means 14 between a first striking surface 18 and a longitudinally spaced second striking surface 20. As will be described in greater detail subsequently, the scraping plate 12 is slideable between the first striking surface 18 and the second striking surface 20 for allowing the scraping plate 12 to be forced to move through the chimney flue 16 by impact against either the first 18 or the second 20 striking surface.
The support means 14 includes an elongated shaft 22 disposed perpendicularly and centrally through the scraping plate 12. It is found that adequate results are provided when the shaft 22 length equals approximately 30 inches. Additionally, 3/4 inch round stock steel rods have been found to supply sufficient rigidity for use as a shaft 22. As the scraping plate 12 is slideable along the support means 14, the shaft 22 provides a guide for restricted movement of the first 18 and second 20 striking surfaces against the scraping plate 12. The support means 14 has a top end 24 disposed adjacent the first striking surface 18. A bottom end 26 of the support means 14 is disposed adjacent the second striking surface 20. As will be readily seen from the Figures, the top end 24 is located at the uppermost end of the shaft 22, and the bottom end 26 is located at the lowermost end of the shaft 22.
A weight member 28 is disposed on the shaft 22 adjacent the bottom end 26. The weight member 28 is slideable along the shaft 22 between the scraping plate 12 and the bottom end 26. In this manner, the second striking surface 20 is defined by the surface of the weight member 28 adjacent scraping plate 12. Satisfactory chimney cleaning results have been achieved by using a weight member 28 having an approximate weight force of ten pounds.
The top end 24 of the support means 14 comprises a perpendicular hammer plate 30 fixedly mounted thereon. As shown in the Figures, the hammer plate 30 may take the form of a small rectangular member. The first striking surface 18 is defined by the surface of the hammer plate 30 adjacent the scraping plate 12. In other words, the surface of the hammer plate 30 facing the scraping plate 12 is used as the first striking surface 18 during the chimney cleaning operation. A hooking means 32 is disposed on the top end 24 of the support means 14 for providing attachment for a chain 34 or cable to move the apparatus 10 through the chimney flue 16. As shown in the Figures, the hooking means 32 can be a ring or eye fixedly attached to the upper surface of the hammer plate 30.
The scraping plate 12 is removeable from the support means 14 for allowing one scraping plate 12 to be exchanged for another of different size. The ability to readily exchange one size scraping plate 12 for another is particularly useful since the size of chimney flues are not necessarily the same from house to house. The scraping plate 12 is made removeable from the support means 14 by providing, at the bottom end 26, fasteners 36 which are removably threaded on the shaft 22. Two fasteners 36 are "locked" on the threaded bottom end 26 by tightening into each other. The weight member 28 is made moveable, or slideable, on the shaft 22 so that by unthreading the fasteners 36, the weight member 28 is slid off the bottom end 26 of the shaft 22, thereby allowing the scraping plate 12 to be removed via the bottom end 26. A new scraping plate 12 of different size or peripheral geometric shape can then be positioned on the shaft 22, followed by the replacing of the weight member 28 and the fasteners 36. The above described method of removing the scraping plate 12 is particularly easy, and can be quickly performed with a minimum of tools.
The scraping plate 12 includes a sleeve member 38 fixedly attached thereto for supporting the scraping plate 12 on the shaft 22 in a perpendicular orientation relative to the longitudinal axis of the shaft 22. The sleeve 38 is mounted on the scraping plate 12 adjacent the weight member 28, as shown in the Figures. Because the scraping plate 12 can be of a relatively small thickness, the sleeve 38 performs the important function of maintaining the scraping plate 12 perpendicular relative to the longitudinal axis of the shaft 22. As described above, the subject apparatus 10 is particularly effective in cleaning the chimney flue 16 as long as the scraping plate 12 is maintained transverse, or perpendicular, to the longitudinal axis of the chimney flue 16, while moving therethrough. The weight member 28 is disposed below the scraping plate 12 to assist in maintaining the scraping plate 12 in a transverse orientation in the chimney flue 16. If the weight member 28 were disposed above the scraping plate 12, the apparatus 10 would have a tendency to shift out of the transverse orientation in the chimney flue 16.
In operation, the subject apparatus 10 is positioned in the top of the chimney flue 16. The support means 14 is raised by the chain 34, while the scraping plate 12 remains frictionally wedged in the chimney flue 16, as shown in FIG. 2. The tension on chain 34 is released, allowing the combined weight force of the support means 14 to create sufficient momentum as the shaft 22 slides through the scraping plate 12. The first striking surface 18 contacts the scraping plate 12 to "hammer" the scraping plate 12 through the chimney flue 16, as shown in FIG. 3. In other words, the chain 34 is repetitiously raised and dropped to force the scraping plate 12 through the chimney flue 16. The hammering procedure is repeated until the apparatus 10 has been moved completely through the chimney. The apparatus 10 is then retrieved by pulling upward on the chain 34. If a minor obstruction or resistance is encountered during the assent, the apparatus 10 is hammered upward, by pulling the second surface 20 repeatedly against the sleeve member 38, as shown in FIG. 4. The upward hammering of the apparatus 10 is relatively easy, as the chimney flue is now clean.
The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims wherein reference numerals are merely for convenience and are not to be in any way limiting, the invention may be practiced otherwise than as specifically described.
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A chimney cleaning apparatus (10) is suspended from a chain (34) for movement through a chimney flue (16) and includes a scraping plate (12). The outer periphery of the scraping plate (12) conforms to the cross-sectional shape of the chimney flue (16) and is rigid for unyielding by moving through the flue (16) in a perfectly transverse orientation to clean all debris therefrom. The scraping plate (12) is slidable along a weighted shaft (22) for enabling the apparatus (10) to be hammered through the chimney flue (16).
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
MICROFICHE APPENDIX
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] This invention relates to the field of musical performances. More specifically, the invention comprises a portable sound reflector designed to be placed beneath the sound board of a piano, and a method for using the sound reflector.
[0006] 2. Description of the Related Art
[0007] FIG. 1 shows a prior art piano 10 . The type of piano shown is a concert grand, which includes a horizontally oriented sound board within frame 12 . Lid 14 covers the top of the frame. Legs 16 support the frame. Keyboard assembly 20 is located on the front of the piano, along with pedal assembly 18 .
[0008] When such a piano is played before an audience, it is customary to raise lid 14 . FIG. 2 shows the same piano with lid 14 in the raised position. Hinge 26 allows the lid to be rotated through an arc. Brace 22 locks into retainer 24 to hold the lid in the raised position. In this configuration the lid reflects the sound originating within frame 12 out toward the audience (to the right in the orientation shown in the view).
[0009] The present inventor previously conceived and developed a device to increase the volume of projected sound from such a piano. FIG. 3 shows the device—lower lid 30 . Lower lid 30 is connected to the bottom of frame 12 via hinge 27 . Pianos traditionally lack any sort of lower lid. The frame is simply open on the bottom. Although the bottom of the soundboard radiates an amount of acoustic energy that is comparable to the top, this energy is traditionally “wasted” because it is not projected toward the audience. The lower lid invention solves this problem. As shown in FIG. 3 , reflected sound 34 is reflected laterally by both lid 14 and lower lid 30 . The inventor filed for a patent on the lower lid invention, and this application was ultimately issued as U.S. Pat. No. 5,301,588.
[0010] While the invention described in U.S. Pat. No. 5,301,588 is quite effective in projecting sound, it has certain shortcomings. First, the invention must be incorporated into the structure of the piano itself. This is not particularly difficult for newly constructed pianos, but it is not easily retrofitted to old pianos. In addition, many older concert pianos are quite valuable and the owners are naturally reluctant to drill holes or otherwise modify the piano from its original state.
[0011] The '588 invention also alters the appearance of the piano. Certain audience members expect a concert piano to appear exactly as it has appeared for the past two centuries, and are hostile to the idea of aesthetic variation even when it significantly improves the sound quality.
[0012] Finally, the '588 invention is obviously part of the piano, and not something that the pianist can carry along from venue to venue. Many pianists desire the enhanced sound available from the lower lid. However, the pianist obviously cannot carry a piano along in his or her travels and must instead perform using whatever configuration resides in the venue.
[0013] Accordingly, it would be desirable to provide a sound reflector analogous to the lower lid in the '588 patent, while also being portable and aesthetically unobtrusive. The present invention provides such a solution.
BRIEF SUMMARY OF THE INVENTION
[0014] The present invention comprises a portable sound reflector designed to be placed under the soundboard of a piano in order to reflect sound laterally. The preferred embodiment includes a main panel which is held in the proper reflecting orientation by a pair of lateral wings. The lateral wings are preferably hinged to the main panel so that the entire assembly may be folded flat for transportation and storage.
[0015] A pair of automatically-deploying stays are preferably included. These fold outward and downward to latch the lateral wings in the deployed state when the device is to be used. The hinges are preferably spring-biased toward the open position. This allows the device to assist the user in the unfolding process.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0016] FIG. 1 is a perspective view, showing a prior art concert piano.
[0017] FIG. 2 is a perspective view, showing the piano of FIG. 1 with the lid propped open.
[0018] FIG. 3 is an elevation view, showing the piano of FIG. 2 with the addition of a lower lid.
[0019] FIG. 4 is an elevation view, showing a conventional piano and the proposed invention.
[0020] FIG. 5 is an elevation view, showing the proposed invention placed beneath a traditional piano.
[0021] FIG. 6 is a perspective view, showing an embodiment of the proposed invention from the front.
[0022] FIG. 7 is a perspective view, showing the embodiment of FIG. 6 from the rear.
[0023] FIG. 8 is a perspective view, showing the rear of a preferred embodiment of the invention.
[0024] FIG. 9 is a section view through the hinge joining the main panel to the left wing.
[0025] FIG. 10 is a section view through the hinge joining the left stay to the main panel.
[0026] FIG. 11 is a perspective view, showing the first step in the folding process whereby the invention is transitioned from the deployed state to the folded state.
[0027] FIG. 12 is a perspective view, showing the invention in the folded state.
[0028] FIG. 13 is a side elevation view, showing how the invention stands on the floor in the deployed state.
[0029] FIG. 14 is a perspective view, showing an alternate embodiment in which the main panel is split into two pieces.
[0030] FIG. 15 is a side elevation view, showing the embodiment of FIG. 14 in a folded state.
[0000]
REFERENCE NUMERALS IN THE DRAWINGS
10
piano
12
frame
14
lid
16
leg
18
pedal assembly
20
keyboard assembly
22
brace
24
retainer
26
hinge
28
hinge
30
lower lid
32
portable sound reflector
34
reflected sound
36
main panel
38
right wing
40
hinge
42
hinge
44
left wing
46
top fold
48
left hinge
50
slot
52
left stay
54
contact tab
56
left stay hinge
58
left block
60
angle piece
62
abutment stop
64
abutment stop
66
center hinge
68
main panel half
70
split panel embodiment
DETAILED DESCRIPTION OF THE INVENTION
[0031] FIG. 4 shows a prior art piano without an attached lower lid. Portable sound reflector 32 is provided to reflect the sound energy traveling downward from the horizontally-oriented soundboard within the piano. Portable sound reflector 32 is placed on the floor as shown. One method of installing the reflector under the piano is to place it as shown and then slide it in the direction of the arrow. It may also be placed beneath he piano without sliding.
[0032] FIG. 5 shows portable sound reflector 32 in a suitable position under the piano. Reflected sound 34 travels laterally after striking portable sound reflector 32 . The position of the sound reflector may be varied to suite the tastes of the individual user, and the position shown in FIG. 5 should be viewed as one possible position among many.
[0033] The portable sound reflector should have an angled reflecting surface suitable in order to project the sound energy laterally toward the audience. The reflecting surface may be held in position by a virtually endless variety of devices. FIGS. 6-12 illustrate two preferred embodiments of such devices.
[0034] FIG. 6 shows main panel 36 being stabilized in position by a pair of wings. Right wing 38 is pivotally connected to main panel 36 via hinge 40 . A left wing—not visible in FIG. 6 —is pivotally connected to main panel 36 via hinge 42 . The hinges allow the two wings to be folded in against the main panel so that the reflector may be stored and transported in a collapsed (flat) state.
[0035] FIG. 7 shows the same embodiment from the rear. Left wing 44 is visible in this view. The reader will observe that left wing 44 is pivotally attached to main panel 36 by hinge 42 . The inventor has discovered that a relatively rigid main panel provides better performance. Accordingly, top fold 46 is added along the upper edge of the main panel to provide rigidity. Reinforcing ribs or other stiffening components could be used as well.
[0036] Many different materials can be used for the main panel and the wings. The main panel in one preferred embodiment is made of 0.375 inch (10 mm) thick clear acrylic. This provides good performance when stiffened by top fold 46 . Clear acrylic may also be used for the left and right wings—though possibly of a lesser thickness. While the use of a clear material is not significant to the actual performance of the invention, it does provide an aesthetically pleasing effect. The portable sound reflector is placed beneath the piano, where it is in shadow. The use of the clear material allows stage lighting from the area behind the piano to be visible to the audience. The result is that most audience members do not even notice the presence of the portable sound reflector.
[0037] Once placed in position, it is important for the reflector to remain stable. Accordingly, the left and right wings in FIG. 7 should be retained in the deployed position shown by a suitable mechanism or mechanisms. Again, there are many different types of mechanisms which could be used. FIGS. 8-12 illustrate one possible mechanism.
[0038] FIG. 8 shows a rear view of the portable sound reflector in the deployed state (right wing 38 and left wing 44 un-folded and positioned to support main panel 36 ). Left stay 52 is pivotally attached to main panel 36 by left stay hinge 56 . It pivots between a folded position and a deployed position. Left stay 52 is shown in the deployed position in FIG. 8 . Contact tab 54 bears against the inward facing surface of left wing 44 . This prevents left wing 44 from folding inward.
[0039] Left wing 44 is prevented from rotating further outward by the operation of left hinge 48 , which will be explained shortly. Left stay 52 is prevented from pivoting further downward by left block 58 , the operation of which will also be explained shortly.
[0040] A mirror image of the stay mechanism for left wing 44 is provided for right wing 38 . However, in the vantage point of FIG. 8 , the stay mechanism for the right wing is hidden behind the right wing and cannot be seen.
[0041] The reader will note in FIG. 8 that two detailed section views are called out. FIG. 9 is a section through the area of left hinge 48 , while FIG. 10 is a section through the area of left stay hinge 56 . FIG. 9 shows one possibility for mounting the left hinge. Angle piece 60 is attached to main panel 36 . Any suitable joining technique may be used for all the joints in the present invention, including the user of fasteners, spot stakes, adhesives, or the like. In the preferred embodiment, angle piece 60 is glued to main panel 36 . Left hinge 48 is likewise glued to angle piece 60 and left wing 44 .
[0042] In studying the geometry of FIG. 9 , the reader will perceive that left wing 44 is free to fold inward toward main panel 36 , but is restricted from rotating further outward by the creation of abutment stop 62 . The abutment stop prevents unwanted further external rotation.
[0043] FIG. 10 shows how one half of left stay hinge 56 is attached to main panel 36 while the other half is attached to left stay 52 . Left block 58 is attached to main panel 36 in order to create abutment stop 64 . In studying this geometry, the reader will note that left stay 52 is free to rotate upward toward main panel 36 but is restricted from rotating further downward from the position shown in FIG. 10 . FIG. 10 shows the deployed state for left stay 52 (corresponding to the view of FIG. 8 ).
[0044] FIGS. 11 and 12 illustrate the process of converting the sound reflector from its deployed state to its folded state. To fold the device, left stay 52 is rotated up against main panel 36 as shown. In the folded state the left stay is approximately parallel to main panel 36 (within about 20 degrees of being parallel). Slot 50 is provided in the left hinge to allow contact tab 54 to clear.
[0045] Once left stay 52 is in the position shown, the user may grasp left wing 44 and fold it inwards. The same may be done for the right stay and right wing 38 . FIG. 12 shows the sound reflector of FIG. 11 in a folded state. The reader will observe that it is a flat object having a minimal thickness. This configuration allows the reflector to be easily transported and stored. In fact, a pianist desiring to consistently use the reflector can simply carry it along on tour.
[0046] Returning now to FIG. 8 , additional design features of the sound reflector will be described. In order to ease the transition of the device from the folded to the deployed state, springs are preferably provided. A first spring is provided within left hinge 48 . This is preferably a torsional spring which tends to bias left wing 44 into a deployed position. A second spring may be provided for left stay 52 . This second spring is preferably also a torsional spring. It tends to bias left stay 52 from the folded position to the deployed position. Additional springs are provided for the mechanisms of the right wing which perform the same functions.
[0047] Returning now to FIG. 12 , the unfolding of the reflector will be described. If the reflector is stowed in a case, the user will first pull it free. The user then rotates the left and right wings into the deployed position. The springs biasing the left and right wings toward this position assist in the opening and—if suitably strong springs are provided—may even automate this process.
[0048] The reflector will then be in the condition shown in FIG. 11 . Once left wing 44 swings into the deployed position, slot 50 will release contact tab 54 . The biasing spring across left stay hinge 56 —aided by gravity—will then rotate left stay 52 down into the deployed position. The same sequence occurs in the mechanisms for the right wing. The user will thereby understand the folding and deploying of the device.
[0049] Turning now to FIG. 13 , some preferred dimensions will be discussed for the invention. The inventor has discovered that the angle (α) between the main panel 36 and the floor is preferably in the range of 30 degrees to 75 degrees, more preferably in the range of 50 degrees to 60 degrees, and most preferably about 54 degrees.
[0050] Returning now to FIG. 6 , main panel 36 preferably has a height of about 24-36 inches and a width of about 60-70 inches. The fold across the top of the main panel is preferably about 1.5 to 2 inches deep.
[0051] In the examples shown, the main panel and wings contact the floor along a bottom edge of each. This need not always be the case, since points or multiple points of contact could be provided for each (such as adjustable rubber feet). The sound reflector as a whole needs three lower contacting portions to be stable, but these need not assume any particular form.
[0052] FIGS. 14 and 15 illustrate still another embodiment in which the main panel has been split in half to enhance portability. FIG. 14 shows split panel embodiment 70 in an erected state. It is configured to reflect sound as for the prior embodiments. However, the reader will observe that the main panel has been divided into two pieces—each of which is designated as main panel half 68 . The two halves are pivotally joined by center hinge 66 . The left and right wings are pivotally connected by hinges as for the prior embodiments.
[0053] FIG. 15 shows the embodiment of FIG. 14 in a fully folded state. Center hinge 66 has been folded so that the two main panel halves 68 lie parallel. Likewise, the left wing 44 and right wing 38 have been folded. The result is a compact design which can be placed in a smaller carrying container.
[0054] The preceding description contains significant detail regarding the novel aspects of the present invention. It is should not be construed, however, as limiting the scope of the invention but rather as providing illustrations of the preferred embodiments of the invention. Numerous other variations will occur to those skilled in the art. Thus, the scope of the invention should be fixed by the claims presented, rather than by the examples given.
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A portable sound reflector designed to be placed under the soundboard of a piano in order to reflect sound laterally. The preferred embodiment includes a main panel which is held in the proper reflecting orientation by a pair of lateral wings. The lateral wings are preferably hinged to the main panel so that the entire assembly may be folded flat for transportation and storage. A pair of automatically-deploying stays are preferably included. These fold outward and downward to latch the lateral wings in the deployed state when the device is to be used. The hinges are preferably spring-biased toward the open position. This allows the device to assist the user in the unfolding process.
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BACKGROUND OF THE INVENTION
This invention relates to transmission of data and in particular to the telemetering of biomedical data of a patient to a monitor for display.
Telemetry systems are now being widely used clinically to monitor post surgical patients and cardiac patients. Typical commercial systems are single channel and are used for ECG monitoring. Some experimental multichannel systems have been reported in literature for use in surgical monitoring and intensive care monitoring. These systems propose a voltage controlled oscillator for each channel with an FM modulated carrier which is demultiplexed at the receiving end utilizing band pass filters and frequency discriminators. Other systems have used pulse width modulation or other conventional modulation formats, and several multichannel systems are now available commercially. Also, systems providing a plurality of data channels for direct connection between a plurality of transducers and/or sensors and a monitor are available commercially.
It is an object of the present invention to provide a new and improved telemetering system especially suited for use with a medical patient and providing a plurality of data channels. A further object is to provide such a system which can be interposed between the conventional transducers and the conventional monitor without requiring changes or adjustments of either. A further object is to provide a telemetering system for a resistance value with the output simulating the resistance at the input so that the monitor operates the same with direct transducer connection and telemetering system connection as input.
It is a particular object of the invention to provide a telemetering system for transmitting a pressure wave such as a recurring pulse pressure wave, providing for transmission of the waveform and values of the peak and trough corresponding to the systolic and diastolic pressures, respectively. An additional object is to provide a telemetering system for transmission of a temperature value with high resolution and high accuracy and low drift so that introduction of a telemetering system does not introduce any additional error in the overall measurement.
These and other objects, advantages, features and results will more fully appear in the course of the following description.
SUMMARY OF THE INVENTION
The inventor includes method and apparatus for transmission of data, particularly resistance values. The system of the invention has as an input the resistance of a conventional transducer and provides as output a resistance identical to the transducer resistance.
The waveform telemetering system includes means for providing an output voltage varying as a function of the transducer output, means for detecting peak and trough values and producing signals corresponding to these values, means for connecting the output voltage and the peak and trough values to the transmission link, means for detecting peak and trough values of the received output voltage, means for comparing transmitted and received peak and trough values and changing the peak and trough of the transmitted output voltage so that the resultant voltage corresponds to the initial voltage, and means for converting this resultant voltage to a varying resistance.
The telemetering system for transmission of a resistance, such as a temperature sensor resistance, includes a bridge with the temperature sensor connected as one arm and a control resistor connected as another arm. Means are provided for varying the control resistor, preferably a counter which selectively drives switches in a resisitor bank, to obtain a balance of the bridge, at which time a signal, preferably a digital code, based on the count state of the counter and corresponding to the resistance introduced into the bridge is transmitted on the transmission link to the receiver. At the receiver a corresponding variable resistance is changed as determined by the transmitted code to produce a resistance value corresponding to the sensor resistance, which resistance value is connected to the monitor.
Both method and apparatus for telemetering are included. While the preferred embodiments provide for transmission of pressure and temperature data, it will be realized that the invention is not so limited and that the transmission of resistance values representing other parameters is included in the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a telemetering system incorporating the presently preferred embodiment of the invention;
FIGS. 2 and 2A are a block diagram for the temperature channel of the system of FIG. 1;
FIG. 3 is a timing chart for the temperature channel of FIG. 2;
FIG. 4 is a block diagram illustrating the transmitter portion of the pressure channels of the system of FIG. 1;
FIG. 5 is a block diagram illustrating the receiving portion of the pressure channels of the system of FIG. 1;
FIG. 6 is a timing chart for the transmit pressure channels;
FIG. 7 is a timing chart for the receive pressure channels;
FIG. 8 is a truth table for the pressure channels receive portion of FIG. 5;
FIG. 9 is a block diagram illustrating the pressure computer circuit of FIG. 5;
FIG. 10 is a schematic diagram of the pressure transducer simulator of FIG. 5; and
FIG. 11 is a timing chart for the receiving pressure channels analog to digital conversion.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The telemetering system of the present invention was designed to make possible accurate, reliable radio telemetry of a sufficient number of physiological parameters to enable a surgical patient to be monitored adequately with no electrically-wired connections to the patient-monitor device. The parameters chosen were as follows:
1. ECG (five lead)
2. Peripheral Pulse (using photo-optical sensor)
3. Temperature (one channel, expandable to two channels)
4. Pressure (two channels)
The major goals of the system were:
1. Employ standard transducers with few or no adjustments required by the user in addition to those normally performed using a conventional patient monitoring system,
2. Provide redundancy by allowing all transducers in use to be interconnected directly, with little or no readjustment, to either the transmitter or to the patient monitor,
3. Require no special display device other than a conventional patient monitor system,
4. Provide a multiplexed data format suitable for recording all parameters on one track of a conventional high quality stereo or monaural cassette recorder,
5. Conform to all applicable current patient safety regulations, and
6. Provide rechargable battery power for the transmitter unit sufficient to enable at least eight hours of continuous monitoring before recharging is necessary.
The overall system is illustrated in FIG. 1. A conventional FM transmitter 20 and a conventional FM receiver 21 are used as the transmission link between the transducers and other pick-ups on the patient and the patient monitor 22. Of course, other transmission links may be utilized if desired.
Leads from conventional ECG electrodes are connected to an ECG preamplifier 23. A conventional pulse transducer 24 is connected to a pulse preamplifier 25. One or more conventional temperature probes 26 are connected to a temperature unit 27. Conventional pressure transducers 28, 29 are connected to a pressure unit 30. A timing unit 31 provides timing reference signals to the temperature unit 27 and pressure unit 30.
The preamplifiers 23, 25, the temperature unit 27, the pressure unit 30, and the timing unit 31 provide seven outputs to a multiplex circuit 33. The multiplex circuit may be a conventional multiplexer which provides the information signal to the transmitter 20. Alternatively, the seven outputs may be transmitted separately without multiplexing.
The signal from the receiver 21 is connected to a demultiplex circuit 35 which produces seven outputs corresponding to the seven outputs connected to the multiplex circuit 33. The outputs from the demultiplex circuit 35 pass through a conventional filter 36.
The patient monitor 22 is a standard device and includes an ECG amplifier, a heart rate computer, a pulse amplifier, a temperature amplifier, two pressure amplifiers, and two systolic/diastolic processors. The output of the ECG amplifier is connected to a multitrace cathode ray tube 40 and to the heart rate computer. The output of the pulse amplifier and both pressure amplifiers are also connected to the tube 40. The output of the heart rate computer is displayed at a digital display 41. The output of the temperature amplifier is displayed at another digital display 42. The output of each pressure amplifier is connected to the corresponding systolic/diastolic processor, with the output of each processor connected to a display 43 which shows systolic and diastolic pressures for the particular channel.
The ECG waveform from the filter 36 is connected directly to the ECG amplifier of the patient monitor. Similarly the pulse waveform from the filter is connected directly to the pulse amplifier of the patient monitor. The temperature data and the reference data from the filter are connected to a temperature unit 44. The channel 1 and channel 2 pressure waves and the pressure data from the filter are connected to a pressure unit 45. The output of the temperature unit 44 is connected to the temperature amplifier of the patient monitor. The outputs for the two channels from the pressure unit 45 are connected to the corresponding pressure amplifiers of the patient monitor. The temperature and pressure units will be described in greater detail hereinbelow.
The system functions to connect the ECG electrodes, the pulse and pressure transducers, and the temperature probes to the patient monitor through a transmission link in a manner such that the inputs presented to the patient monitor correspond to that which would be presented if the electrodes, transducers, and probes were directly connected to the patient monitor in the conventional manner. This permits remote positioning of the patient monitor from the patient and this may be accomplished without requiring any direct wire connections therebetween. The transducer and transmitter portion may be battery powered and quite small, permitting installation in a small volume on a patient trolley and permitting movement of the patient trolley without concern for trailing wires. The wire connections from the receiver section to the patient monitor are directly interchangable with the wire connections from the electrodes, transducers and probes. No adjustments or calibration are needed other than the normal patient monitor adjustments since all outputs from the receiver unit are identical to the corresponding electrode, transducer and probe outputs. Thus, in the event of failure of the telemetry system, any or all transducers may be immediately connected directly into the patient monitor system with no necessity for recalibration.
ECG & Pulse Channels
The ECG preamplifier 23 is of conventional design and uses a five-lead input cable. The amplifier is designed primarily to measure the V-5 lead. A three-lead cable can be used to measure leads I, II, or III by use of a suitable adapter. The amplified output of the ECG amplifier is connected to the input of the multiplex circuit 33, to be multiplexed with other signals and transmitted.
The pulse transducer preamplifier 25 provides regulated DC excitation to the light source of the transducer 24 and amplification of the phototransistor output which is then routed to the multiplex circuit 33.
Transmit/Multiplex Functions
Multiplexing at unit 33, FIG. 1, is performed at a 2 KHz rate using an eight-channel pulse-position format, with one channel used only for synchronization. The final pulse-position modulated format is derived from a basic pulse-width modulated waveform. The pulse position format was found to be more desirable for FM transmission with commercially available entertainment-type transmitters and receivers because of the elimination of most of the low frequency components present in the pulse width modulation format.
The pulse-position modulation information is applied to a commercial FM microphone transmitter 20 operating at approximately 88 mHz, and at a maximum input power of 100 mw.
Demultiplex Circuit
The function of the demultiplex circuit 35 is to separate each of the seven channels of data from the pulse-position modulated waveform provided at the output of the FM receiver 21.
In the system disclosed, the pulse position modulation is first applied to an automatic gain control which provides approximately 4 vpp out for input signals ranging from 20 mv pp to 6 vpp. The modulation is then applied to a squaring circuit with hysteresis, which ignores baseline noise on the waveforms and converts the modulation to a pulse-width modulated format. Further squaring is provided by a comparator. Conversion of pulse-widths to amplitudes is accomplished with a conventional operational amplifier-integrator. Two identical sample-and-hold amplifiers are used to sample alternate channels so that cross-talk between channels is minimized, and maximum efficiency of data recovery is achieved.
Temperature Channel
Temperature information ordinarily is transmitted as a voltage or frequency proportional to temperature. This mode of operation requires careful calibration of the circuitry at the transmitter unit. In order to obtain drift free measurement in the system of the present invention, a precision resistance measuring bridge and a digital circuit which encodes the resistance value for transmission to the receiving circuit is utilized. The receiving circuit produces an electrical resistance identical to the temperature sensor resistance for presentation to a conventional monitor which may measure, record and/or display the temperature. This permits transmission of temperature information with no more drift than if the temperature sensor or probe was connected directly to the monitor. Resolution in the measuring system is a function of the number of digital increments utilized and in the embodiment illustrated herein, 128 increments are used providing ±0.1° C. resolution.
Measurement of temperature using a thermistor probe is conventionally done by developing a voltage-proportional-to-temperature using a bridge amplifier, then developing a numerical readout based upon the voltage obtained. The system of the present invention differs from the conventional system in that there is no need to duplicate the amplifier and display system at the patient, and that by utilizing the conventional patient monitor for display, user convenience is greatly enhanced. The output from the temperature unit 44 is electrically identical to the output of the temperature probe 26 permitting use of the conventional patient monitor 22 for display of telemetered temperature information.
A preferred embodiment of the temperature unit 27 is shown in FIGS. 2 and 2A, and timing of waveforms used for temperature measurement is shown in FIG. 3. Thermistor temperature probes often contain two separate thermistors, so that two separate resistance measurements must be made for each temperature measurement, Each thermistor 26 is connected into a bridge circuit 50 containing two precision resistors 51, 52 and seven electronically switchable resistors 53, of value R, 2R, etc., in parallel with a fixed resistor 54. The fixed resistor is equal to the largest expected thermistor resistance (corresponding to the minimum temperature measurement desired). The seven switchable resistors are switched in different combinations to obtain 2 7 discrete resistance values, or 128 different values. With all seven resistors in parallel with the fixed resistor, the total resistance is equal to the lowest expected resistance of the thermistor (corresponding to the highest temperature desired). Over a temperature range of 15° C. to 40° C., 128 discrete steps of resistance variations provide a temperature resolution of approximately 0.2° C., or ±0.1° C.
The seven resistors 53 are switched by switches 55 controlled by a binary counter circuit 56 until the comparator 57 senses that the bridge is close to balance. The binary value of resistances in the circuit at that instant in time is transferred in seven-bit parallel binary words into a storage register 58. The bits are then clocked out of the register 58 serially by 10 Hz clock pulses to be multiplexed onto one data channel, and the 10 Hz reference pulses are routed to another data channel of the transmission link.
Data words for the two resistance values of the two probes are alternately clocked onto the data line to form a 16-bit word consisting of 14 data bits, with bits 15 and 8 unused, since synchronization and storage occur during the time of the two unused data bits.
Reference clock pulses and other timing waveforms are generated in a conventional manner. The reference channel contains 15 narrow pulses (bits 0-14) and one wide pulse (bit 15) which is used for frame synchronization. A new temperature measurement is made every frame, or approximately once per 1.6 seconds. Typical thermistor resistance calculations are shown below.
The resistance R of the probe thermistor is represented by the following relation:
1/R=(Σ2.sup.n)g+g.sub.o
where
g.sub.o =1/R.sub.max
Δg=(1/R.sub.max -g.sub.o)/2.sup.n
n=number of resistors to be switched
N=data bit numbers
For the temperature T 1 in FIG. 2A with data code 0010111 and resistance values shown
R.sub.1 =1/(23Δg+g.sub.o)
g.sub.o =1/9k=1.1111×10.sup.-4
Δg=(3.3333×10.sup.-4 -1.1111×10.sup.-4)/128=1.7360×10.sup.-6
R.sub.1 =1/(23×1.7360×10.sup.-6 +1.1111×10.sup.-4)=6620.76 ohms
Similarly for T 2 in FIG. 2A with code 0101100
R.sub.2 =1/(44Δg+g.sub.o)
g.sub.o =1/54k=1.8518×10.sup.-5
Δg=(5.5555×10.sup.-5 -1.8518×10.sup.-5)/128=2.8934×10.sup.-7
R.sub.2 =1/(44×2.8934×10.sup.-7 +1.8518×10.sup.-5)=32001.1 ohms
Temperature Decoding
The temperature unit 44 for received signals contains identical switched-resistor networks to those in the temperature unit 27, providing a resistance value to the temperature amplifier of the monitor 22.
Temperature data is received in a format containing two seven-bit binary words per frame, representing the two resistance values necessary to simulate the two temperature probe resistances for the given temperature being measured. Each binary word is serially loaded into a shift register and then read out in parallel and connected to seven CMOS switches (two type 4066 integrated circuits) which connect the proper resistances in parallel to reproduce the two temperature probe resistances measured by the transmitter unit. These resistances are connected to the temperature probe input of the patient monitor so that the temperature may be determined and displayed.
Pressure Channels, Transmit
The pressure unit 30 of the transmit section is shown in greater detail in FIG. 4 and the operation is shown in the timing chart of FIG. 6.
The pressure unit 30 includes two pressure transducer bridge amplifiers 101, 102 with common bridge excitation supply, dual-channel systolic/diastolic detectors 103, 104, dual automatic level control 105, 106 for pressure-wave amplitude control to enhance signal-to-noise at low pressures, and an analog-to-digital converter 107 with associated data registers for converting parallel digital pressure reference and calibration data into serial data suitable for multiplexing and transmitting.
Two data channels are required to transmit complete information for one pressure channel while only three data channels are required to transmit complete information for two pressure channels. One channel is used for alternately transmitting discrete digital values of systolic and diastolic pressure for each of the two pressure waveforms and the remaining two data channels are used for transmitting the two pressure waveforms. The digital data is in the form of four 16-bit words which are transmitted serially. Each 16-bit word contains 12 data bits, two identification bits, and two unused bits. Preferably analog waveform information is first amplitude adjusted by the automatic level units 105, 106 to provide better signal-to-noise ratio; no absolute pressure waveform amplitude or offset is retained since this is added at the receive section from data received from the pressure reference channel.
Pressure Bridge Amplifier
The two pressure bridge amplifiers 101, 102 are of conventional design and preferably employ extremely low-drift integrated circuit amplifiers combined with a well-regulated excitation-voltage supply so that drifts due to non-transducer related sources are kept to a minimum, typically much less than 1 mm Hg. Balance indicators are provided for each channel so that transducers with adjustable zero-balance controls can be conveniently balanced. No amplifier balance or sensitivity adjustments are needed since calibration factors and any residual offsets are taken care of by the pressure module of the patient monitor 22 just as if the transducers were connected directly into it.
Systolic/Diastolic Detector
The systolic and diastolic detector circuits 103, 104 are located on board 6, FIG. 4. The board contains two identical systolic detector/memory circuits and two identical diastolic detector/memory circuits as well as two identical auto level control circuits 105, 106.
The systolic detector/memory circuits and diastolic detector/memory circuits are identical in function except for the polarity of the feedback to the peak detector switch. Peak detection and memory are performed alternately by providing the proper logic levels so that a CA 3130A integrated circuit is first connected as a comparator, causing the switch to sample the incoming waveform, then as a conventional unity-gain high input-impedance buffer to enable reading of the voltage stored on the memory capacitor, which represents the previously determined systolic or diastolic value. After the systolic or diastolic value is read, a reset pulse causes the memory capacitor to be charged to a voltage equal to the voltage of the pressure waveform at the instant of the reset pulse, so that a new value of systolic or diastolic pressure can then be determined. A truth-table of circuit functions of the systolic/diastolic/memory circuits is shown in FIG. 8.
Automatic Level Control
The automatic level control circuits, 105, 106 are located on board 6, FIG. 4. These circuits adjust the amplitudes of the AC-coupled pressure waveforms according to the value of pulse-pressure. Discrete pulse pressure values for each waveform are computed from values obtained by the systolic/diastolic detector circuits. The pulse pressure value is then stored and applied to a field effect transistor, operating in the variable resistance mode and connected into an attenuator circuit, so that small amplitude pressure waveforms are caused to be amplified more than large amplitude pressure waveforms.
Analog to Digital Conversion
The analog to digital converter 107 on board 7, FIG. 4, generates additional timing waveforms required for the pressure channels as well as performing A-to-D conversion of the systolic and diastolic information. FIG. 6, the Timing Chart, Pressure Channels, Transmit, shows waveform details. Preferably, a precision monolithic integrated circuit 12-bit analog-to-digital converter is used in conjunction with a precision voltage reference so that digital pressure reference information transmitted to the receiver/demultiplexer can be used to reconstruct the original pressure information within the required overall accuracy specifications.
Pressure Channels, Receive
The pressure unit 45 of the receive section of FIG. 1 is shown in greater detail in FIG. 5 and the operation is shown in the timing chart of FIG. 7.
The pressure unit 45 includes a digital-to-analog converter 110 for converting digitally-encoded values of systolic and diastolic pressures to analog voltages, a dual-channel systolic/diastolic detector/memory circuit 111 for measuring and storing systolic and diastolic values of the two received pressure waveforms, two analog computing circuits 112, 113 for continually adjusting pressure waveform amplitude and offset, an analog-to-digital converter 114 which provides digital encoding of the two calibrated pressure waveforms, and two pressure transducer simulator circuits 115, 116 which convert the A-to-D digitally encoded waveform data into resistance changes which can be interpreted by the patient monitor pressure modules as pressure transducer signals.
The digital converters (A-to-D and D-to-A) are standard monolithic integrated circuits and their associated timing circuitry is of conventional design.
The function of the receive pressure measuring circuitry is to use the reference channel digital information to effect accurate amplitude and offset correction of two pressure waveforms and then cause resistance changes proportional to each waveform to be presented to the respective pressure transducer inputs of a conventional patient monitor 22. The principal difference between the telemetered pressure signals and direct-coupled pressure signals is that a periodic amplitude and offset adjustment is made upon the waveforms of the telemetered signals. Normally only a negligible change in waveform gain and offset will occur between the instant the reference systolic and diastolic values are measured by the transmit unit until the instant of waveform adjustment at the receive unit (approximately eight to ten seconds). This time lag is necessary because of information-bandwidth constraints in the specific system disclosed, and was the result of a tradeoff between the number of channels desired and accuracy of pressure measurement required. Some advantages of the method are, (1) accuracy of pressure readings (after initial stabilization time) and (2) attenuation of cross-talk noise on the pressure waveform (due to increase in gain at the transmitter and readjustment of gain at the receiver).
Pressure Computer Circuits
The pressure computer circuits 112, 113 are analog computing circuits composed of operational amplifiers and analog multipliers which together perform gain adjustment and offset adjustment of the received pressure waveforms. This is done by utilizing digitally encoded systolic and diastolic pressures measured by the pressure measuring circuits in the transmitter unit as reference values to which the received waveforms may be compared and adjusted accordingly. One computer circuit is shown in greater detail in FIG. 9, where
P a =Systolic pressure+50 mmHg
P b =Diastolic pressure+50 mmHg
ΔP o =Offset pressure
k 1 =Standard gain constant of pressure signal=20 mv/mmHg
k 2 =Gain constant of received pressure waveform, V/mmHg
k 3 =Gain constant of zero offset of received signal, V/mmHg
p(t)=Received pressure waveform (Time varying pressure)
The two types of operations which are performed are gain adjustment and offset adjustment. Gain adjustment is performed by subtracting the diastolic reference value k 1 P b , from the systolic reference value, k 1 P a , and dividing this value into the value obtained by subtracting the received waveform diastolic-plus-offset value, k 2 P b +k 3 ΔP o , from the received waveform systolic-plus-offset value, k 2 P a +k 3 ΔP o , to obtain a gain ratio k 1 /k 2 , which is then continuously multiplied times the received pressure waveform, k 2 p(t)+k 3 ΔP o , to adjust its gain. The amplitude adjusted waveform plus offset, then, can be represented by the term, ##EQU1##
Zero offset correction is performed by multiplying the received waveform systolic pressure-plus offset, k 2 P a k 3 ΔP o , by the previously obtained gain ratio, k 1 /k 2 , subtracting the reference systolic value, k 1 P a , to obtain the offset error, ##EQU2## and then continuously subtracting the offset error from the gain-adjusted waveform-plus-offset, ##EQU3## to obtain the final gain and offset adjusted waveform k 1 p(t).
In the event that the apparent systolic minus diastolic pressure of the received waveform (pulse-pressure) is below about 10 mmHg, the gain adjustment circuitry is inactivated and only the offset circuit remains in effect. However, 10 mmHg measured from the received waveform corresponds to an actual value of perhaps one or two mmHg due to the increased gain applied to the pressure waveforms at the transmitter by the automatic level control circuitry.
Pressure Transducer Simulator and A/D Conversion
One pressure transducer simulator unit 115 is shown in greater detail in FIG. 10 and operation of the converter 114 and units 115, 116 is shown in the timing chart of FIG. 11.
The simulator circuit of FIG. 10 is basically a conventional four-arm resistance bridge with two digitally-controllable variable arms. AC or DC excitation is applied externally by the respective pressure module of the patient monitor 22. Bridge arm resistance changes are effected by 12 precision resistors R12-R1 of ratio R, 2R, etc., in parallel with each of two arms of the bridge, and which are caused to be switched in and out of the circuit in a binary-coded fashion. A binary code corresponding to pressure measured at a given instant in time is applied to the twelve switches Z1, Z2, Z3 which control the resistors in parallel with one arm of the bridge, while at the same instant, the binary compliment of that code is applied to the twelve switches Z4, Z5, Z6 controlling the resistors in parallel with the opposite arm of the bridge. Bridge linearity is thus preserved, since a significant non-linear effect would result if only one arm of the bridge were varied.
The twelve bit binary code is generated by the A to D converter 114, which alternately samples the two gain and offset adjusted pressure waveforms. Each channel is sampled approximately 1250 times per second. The twelve-bit binary words representing instantaneous pressure measurements are stored in two 12-bit parallel-in/parallel-out shift registers 118, 119, one register for each pressure channel. Shift register outputs are connected directly to one bank of bridge-arm resistor-control switches, and the complement (inverse) of these outputs are connected to the opposite bank of bridge arm resistor control switches.
The upper frequency response limit of each pressure channel corresponds to one-half the sample rate, or 625 Hz. The component presently used for the A/D converter 114 has a maximum possible resolution of one part in 2 12 , but is guaranteed for only one part in 2 10 . Therefore guaranteed full scale resolution is one part in 2 10 or one part in 1024. The full scale range of pressure of the A/D converter is 500 mmHg, so that guaranteed resolution is 500/1024, or better than 1/2 mmHg.
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A system for telemetering data from a patient to a monitor permitting direct connection of patient's sensors and transducers to the monitor and permitting telemetering by radio or wire without requiring changes in transducer or monitor design or adjustment or calibration. A telemetering system which presents to the monitor variable resistances identical to the varying resistances produced by the transducers at the patient. A temperature transmission channel wherein a thermistor resistance is digitized for transmission, with the digital data being utilized to generate a resistance at the receiver corresponding to the thermistor resistance. A pressure transmission system providing for transmission of waveform and peak and trough values of the waveform, with the waveform being reconstituted at the receiver and converted to a varying resistance for connection to the monitor, simulating the original pressure transducer resistance.
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BACKGROUND OF INVENTION
[0001] This invention relates to the transcription of sequences of genes and the structure of other molecules into computer readable data.
[0002] Currently, many firms are involved in discovering and transcribing DNA genomes. By knowing the exact sequence of base pairs in genomes, many advances in health care and plant sciences are possible. Frederick Sanger developed the basic chemistry in the 1970's.
[0003] In the chain termination method of DNA sequencing, a small portion of a DNA is replicated. The bio-chemical replication process includes fluorescent molecules that stop the replication process at random points. By using 4 different types of fluorescent molecules, the color indicates which base pair the molecule is replacing.
[0004] The assorted DNA portions are separated by chromatography into bands of differing molecular lengths. By looking at the sequence of colors, one can determine the sequence of base pairs in the whole DNA portion under study.
[0005] Problems:
[0006] Only small DNA portions (500 to 1000 base pairs) can be sequenced at a time. Determining the sequence of a whole genome takes a prohibitively long time and is costly.
[0007] In another method, Gene Chips probe for specific genes. An array of biochemical probes is deposited on a substrate. After chemical reaction, the color of each probe is measured to determine the result of each probe.
[0008] Problems:
[0009] Only a relatively small number of specific genes can be probed with this method.
[0010] SPM:
[0011] Scanning Probe Microscopes use charges, conduction or molecular forces along with atomic scale positioning to measure the shape of a surface. This has been suggested as a possible way to measure the different base pairs of a DNA molecule. There are many difficulties inherent in this proposition. Holding and positioning the helix of a DNA molecule while scanning it with a carbon nano-tube probe would be problematic and slow.
[0012] X-Ray Diffraction:
[0013] The DNA molecule is flexible so it doesn't form a good crystal. Instead, fibers of oriented DNA molecules must be used. But this fiber method does not provide good resolution. Even if a sufficient resolution could be achieved, the complexity of DNA requires that a huge number of x-ray images must be made and analyzed. Even with automated machinery and computer processing, it is a very time consuming process.
SUMMARY OF INVENTION
[0014] In accordance with the present invention, a microelectronic circuit can more directly measure the characteristics of a molecule under study to identify it and determine the pattern of its components. The result is that complete gene sequences may be read rapidly at a minimal cost.
BRIEF DESCRIPTION OF DRAWINGS
[0015] The FIGURE shows a perspective, cross section view of the relevant portion of one embodiment of the invention. The upper surface of the microelectronic chip is covered or layered with a multitude of conductive traces. The traces both move and sense the target molecule.
[0016] Long, parallel traces 1 are called aligners. They are used to move a target molecule radially or sideways to the “Sensing track” 2 . Below and on the walls of the sensing track are more aligners. These aligners help orient the target molecule and hold it in the sensing track.
[0017] In the sensing track is a pattern of conductive elements. Some of these elements are know as ‘Movers’ 3 . The movers can be used to electrostatically peristaltically move the target molecule axially along its long axis.
[0018] Other conductive elements are known as “Sensors” 4 and are used to sense the presence of specific molecules.
DETAILED DESCRIPTION
[0019] Gene Reader design:
[0020] The invention has patterns of conductive traces connected to microelectronic circuits. The conductive traces are designed and positioned to allow for sensing and positioning of molecules. The microelectronic circuits control the probing forces and interpret the resulting signals. The microelectronic circuits also handle communication with external electronics.
[0021] Aligners:
[0022] One set of structures on the chip is designed to attract, straighten and/or channel the target molecule. If the target molecule, or portions of the target molecule have a consistent dipole direction, a plurality of wires can create a corresponding dipole moment which may be used to guide the target molecule to the desired location on the chip, straighten it and align it as desired.
[0023] The aligners may be long wires or segmented wire sets as show in the FIGURE. By using sets of wires, the aligners can provide a twisting force to the target molecule. This force can be used to straighten the DNA helix.
[0024] The aligners can be used to deform the target molecule. By using long, parallel aligners, long and straight channels of electrostatic potential are formed. The dipole moment of the target molecule will force the target molecule to straighten to the shape of the aligners dipole field.
[0025] The aligners may be used to untwist a DNA molecule. By segmenting the aligners, making an array of them and driving them with the proper phase relationships, one end of the DNA can be rotated in a direction that is not matched by the other end. This can be used to twist the DNA to a precisely determined helix or to completely straighten the DNA, simplifying the processes of moving it and reading it's bases.
[0026] Movers:
[0027] Zones on the gene reader chip can use charges, currents, magnetic forces, mechanical probes and/or optical forces to move and bend the molecules into various desired alignments and positions. These zones can be at different depths under the chip surface, on or near the chip surface and above the surface.
[0028] Small charged areas in close proximity to the target molecule's substructures will be used for small movements and to lock the target in place so it may be measured. When used together, the charged areas function as the stator in a linear motor designed to move the target molecule along the desired path. The target molecule may be moved as a stiff unit or flexed peristaltically in a fashion similar to the movement of a caterpillar. The distance between individual stator elements and the distance between the repeating elements of the target molecule can fall into a wide variety of ratios. By using a larger stator separation, production of the chip is simplified. When construction techniques can produce smaller stator elements, a much smaller distance between each of them can allow more precise positioning of the target molecule.
[0029] Target molecules can also be moved by creating a surrounding magnetic field and then driving a chosen amount of charge through a conductive portion of the target. The resulting force will move the target a precise distance.
[0030] Sensors:
[0031] Conductive areas can transmit electrostatic and magnetic forces to the substructures of the target molecule. The target will then alter those forces and/or produce other forces that will be measured by structures on the chip. For example: The rate at which a conducting area on the chip can be charged is affected by the presence of the dipole field of the target molecule. This can be used to determine not only the presence of a target molecule, but also what type of target molecule substructure is adjacent to the sensor.
[0032] There are several ways to measure a dipole moment. In the dielectric dispersion measurement technique, an oscillating current is placed on a plate above the chip and on the sensor wires in the chip. The voltage measured on the plate and wires is lower if a dipole (the tag) is between the plate and the sensor.
[0033] In the fluorescent emission measurement technique, the emission of some wavelengths can be dependent upon the tag having a dipole moment. Measurement of precise colors emitted under different conditions can then be used to detect and differentiate dipole tags.
[0034] Multiple Sensors:
[0035] The chip can have a multitude of sensors ( 4 ). This allows for error checking and faster determination of the molecule being observed. The elements used for sensing and positioning of the target molecule can operate simultaneously or sequentially. Different sensors can be tailored to respond to different tags.
[0036] Tags:
[0037] Since the outside of a DNA helix is uniform, it is hard to measure directly. By splitting the chain open and attaching readily identifiable molecules to the bases, the gene reader chip can easily identify the corresponding structure of DNA bases.
[0038] Tags may be designed to mate with individual bases, or to larger sequences of bases. By mating with several bases, the measurable portion of the tag may be made larger. While more tag types will be needed, this makes design and manufacture of the gene reader chip simpler.
[0039] Handles: Molecules can be attached to the target which allow the gene reader chip to readily move, position and hold the target molecule in place. The same molecules can be used as both tags and handles. A combination of the structures that naturally occur in the target molecule and added structures may be used for tags and handles.
[0040] The tags and handles can also be designed to change the shape and stiffness of the resulting target molecule. For instance, by adding molecules that link with each other, the spiral of a DNA helix can be straightened and a new, stiff backbone created.
[0041] This will make it simpler for the movers and sensors to transport and measure the target molecule.
[0042] Chip Microstructure:
[0043] The physical shape of the gene reader chip may be designed to facilitate the smooth passage and containment of the target molecule. An appropriately sized groove with funnel shaped entrance and exit will help guide the molecule. If the chip is to measure a helix molecule, the groove can be spiral shaped or a series of parallel grooves that mesh with the twists of the helix.
[0044] Chip Layers:
[0045] Structures to sense and/or move the tags can be on the surface, buried in, below or suspended above the chip.
[0046] Sequential Addition of Tags:
[0047] Since the mating surfaces of the tags are designed to adhere to complimentary base pairs, the tags themselves can adhere to each other. To prevent complications from this effect, 2 non-complimentary tag types can be allowed to adhere to the split DNA strand. After all the relevant DNA bases have been tagged, the other tag types may be added. This limits the waste of tags while properly tagging the target molecule.
[0048] Measurement in Parts:
[0049] The target molecule may be measured in several passes. During the first pass, a tag for one base or set of bases is used. The gene reader chip notes either the presence or absence of a tag and its type at each position along the target molecule. Subsequently, copies of the target molecule are tagged to reveal the other possible bases or base groups. The multiple readings are then put together to reveal the complete sequence of the target molecule. The advantage of this method is that the wide varieties of tags do not have to be distinguishable from each other. Each tag can be larger and more easily read. In each pass, 1 or more distinguishable tag types may be used. This can speed up the reading process and allow the multiple readings to be easily reassembled into a single, complete sequence.
[0050] Mutations:
[0051] Since the bases in a DNA can mutate, special tags can be designed which mate with the mutated bases and convey that information to the sensors on the gene reader chip.
[0052] Design of the Tags:
[0053] Tags can be made in a wide variety of shapes and formulas. One method is to make parallel layers of carbon rings. The rings in one layer will be double bonded while the rings on the other layer will have their carbons terminated in hydrogen atoms. This results in a flat, rigid structure with a measurable electronic dipole. The tag's dipole moment allows it to be positioned by the gene reader chip. The dipole strength of each tag can be individually tailored. By measurement of the dipole potential and position, the identity of the tag may also be determined.
[0054] These tags may be made in differing sizes. The width and length of tags can be used to identify them. Both symmetrical and non-symmetrical tags may be used. Since the width of a tag affects both the position and the strength of its dipole moment, the sensors can measure these characteristics to determine which tag is being sensed.
[0055] Direct optical measurements may be also be used. Both frequency and intensity can identify each given tag. Optical piping and high frequencies (including x-rays) of light can facilitate this method. Optical methods may be used in conjunction with dipole measurement and other methods. Optically active tags can be designed. For example: bonding or caging a crystalline silicon nano-particle to the tag will result in a molecule with an ultra-bright fluorescence.
[0056] Direct Measurement:
[0057] If the structures on the gene reader chip are made fine enough and the target molecule has the appropriate characteristics, the target molecule and its micro-details may be determined directly without the use of tags and/or handles.
[0058] Chip Construction Techniques:
[0059] Since the structures on this chip are extremely small, some indication of a method of construction needs to be given.
[0060] One method is to deposit a conductive film on a substrate. A fine probe such as an atomic force microscope probe may be used to carve the film, creating conductive and insulating areas. An atomic force microscope may also be used to pick up individual atoms and place them in desired spots. A layer of insulating material may then be used to smooth the resulting surface. Additional layers of conductive and/or insulating materials may be applied to create all the sensing and controlling zones as well as the desired physical shape of the “gene reader chip”.
[0061] Operation:
[0062] A sample of cells is placed in a cuvet. A lyseing fluid is added and/or the cells are washed over a series of spikes to release the DNA. The DNA leaks out and is separated from the cells' membranes. In an appropriate sequence and timing, other chemicals are added to split the DNA helix and add the tags and handles. As the tag molecules are allowed to bond with the single helix strand, a readable molecule is formed. The DNA molecules are then transported to and positioned on an electronic chip, “the gene reader”. The chip uses aligners to move, untwist and position the target molecule along its reading section. The chip then sends pulses to its sensors, measures the responses and determines which tag is present at each sensor. After reading a tag, the chip pushes and pulls the molecule along so the next tag is positioned for reading. This continues until the whole desired section of the molecule has been determined.
[0063] A whole chromosome may be sequenced in this fashion. A plurality of sensing tracks can allow many different chromosomes may be read at the same time.
[0064] The gene reader chip and external computers assemble the data into the correct form and order.
[0065] Physical Guide Channel:
[0066] The FIGURE shows the microchip with a physical channel for the DNA to follow.
[0067] Other Embodiments—Electrostatic Guide Channel:
[0068] An electrostatic channel for the target molecule can be created from wires which create appropriate force gradients.
[0069] Other Embodiments—Simple Construction:
[0070] The chip may be designed for simpler construction with as few layers as possible ( 3 )—horizontal conductors, insulator, vertical conductors.
[0071] Other Embodiments—Sensor Shapes:
[0072] The sensors may be designed to have a physical structure that partially mates with the DNA bases to be measured. By meshing with the target molecule, the sensors can give a highly accurate measurement of complex molecular structures. This process in effect forms the tags directly into the sensor arrays.
[0073] Other Embodiments—Projectile Sensing:
[0074] A sensor can be designed that operates by propelling an atom or group of atoms at the molecule. The atom bounces off the target molecule with a distinguishable direction, energy and charge. The sensors measure the presence of the resulting projectile to determine the structure of the target molecule.
[0075] Conclusion, Ramifications, and Scope:
[0076] This process can be used for DNA, RNA and many other molecules.
[0077] Speed:
[0078] Much, much faster than chemical and diffraction methods.
[0079] Accuracy:
[0080] It not only identifies genes and other groups of base pair sequences (like the chemical methods), but also creates a complete sequence map of the whole molecule.
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An electronic microchip in possible conjunction with chemical tags for rapidly determining the sequence of genetic material. The tags are designed to facilitate automatic positioning and identification of genetic bases. The electronic microchip actively positions the subject material, senses the characteristics of the tags and transmits that information.
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This is a divisional of co-pending application Ser. No. 796,720 filed on Nov. 8, 1985 U.S. Pat. No. 4,687,640.
FIELD OF THE INVENTION
The present invention relates generally to a chlorine gas filtering material suitable for use in a chemical oxygen generator and to a method of making it, and more specifically to a filtering material suitable for use in a chemical oxygen generator of the type utilizing a chlorate candle and which is disposed within the shell of the generator and is capable of removing chlorine gas from the oxygen as it is being discharged, the filtering material being prepared by impregnating a porous manganese dioxide and copper oxide catalyst with sodium hydroxide.
BACKGROUND
Chemical oxygen generators are well known and are used for a variety of purposes, such as for example providing oxygen to the face masks stored within a housing located above each passenger and crew station in an aircraft as shown in U.S. Pat. No. 3,536,070. These chemical oxygen generators typically are provided with an oxygen liberating composition such as a chlorate or a perchlorate which generates oxygen when progressively decomposed after ignition, the oxygen generating composition being disposed within an insulated canister. The composition further may include a metal powder such as iron or carbon for burning and supplying part of the heat needed for combustion, a binder such as inorganic glass fibers for holding the mass together and aiding in the even decomposition of the chlorate or perchlorate, and a peroxide for chemically eliminating after start up the traces of chlorine gas released during thermal breakdown of the chlorate or perchlorate. These compositions are generally called chlorate candles, the candles being disposed within an insulated metal housing. In addition, as shown in U.S. Pat. No. 3,756,785 a chemical and mechanical filter is customarily provided at the discharge portion of the chemical oxygen generator for filtering out airborne particles, vapors and gases such as carbon monoxide. The filtering material typically includes hopcalite which is a well known specially prepared mixture of manganese dioxide and copper oxide in granular form which converts carbon monoxide into carbon dioxide. As most prior art chemical oxygen generators also discharge some free chlorine, the hopcalite also acts as a chlorine scrubber or getter. While hopcalite is an effective chlorine scrubber at relatively low volumes of air flow and low concentrations of chlorine, it is not effective at high flow rates and high concentrations. Also, normally hopcalite will outgas chlorine at high temperatures. With the development of a new series of chemical oxygen generators which exhibit higher oxygen flow than prior chemical oxygen generators, there is a requirement for a more effective chlorine getter. This is particularly true since the new series of chemical oxygen generators generate a large volume of chlorine in the range of 2000-3000 ppm during the first 30 seconds after activation.
It has been known in the past that activated carbon when coated with sodium hydroxide, as shown in U.S. Pat. No. 4,215,096 and granular pumice also when coated with sodium hydroxide, as shown in U.S. Pat. No. 2,442,356, serve as chlorine getters. However, while sodium hydroxide coated activated charcoal is a very efficient chlorine getter, activated charcoal is not suitable for use in an oxygen generator of the type referred to. Thus, when activated charcoal was tried in such a generator, the activated charcoal actually started to burn, causing a burn through in the stainless steel housing of the generator. The sodium hydroxide pumice was also tested and gave unacceptable test results. A hopcalite sold under the trade name of Carulite 200 by the Carus Corporation was also attempted to be coated by sodium hydroxide. However, when the Carulite 200 was added to the sodium hydroxide water solution rapid boiling occurred, and breakdown of the Carulite resulted. The consistency of the Carulite after being added to the sodium hydroxide solution was that of a sludge. It is believed that the Carulite 200 brand of the hopcalite is produced by the acid method. When used in this specification, acid method hopcalite is hopcalite produced generally by that method disclosed by Lucile S. Mathieu-Levy in Ann. mines 138, 23-40 (1949), Chemical Abstracts 44, 4764f, wherein hopcalite-type catalysts is prepared from MnSO 4 , CuSO 4 , H 2 SO 4 and H 2 O. Also, when used in this specification, carbonate method hopcalite is hopcalite produced generally by that method disclosed by Etienne Cheylan in Mem. services chim. etat (Paris) 31, 299-303 (1944), Chemical Abstracts 40, 5986 wherein a hopcalite-type catalyst is prepared from Cu and Mn salts and an alk. carbonate, preferably (NH 4 ) 2 CO 3 .
OBJECTS OF THE INVENTION
It is an object of the present invention to provide an efficient chlorine gas getter for use in a chemical oxygen generator of the type referred to, the chlorine gas getter consisting of hopcalite prepared by the carbonate method, the hopcalite having a high surface area in the range of 100 m 2 /gm, which material is impregnated with sodium hydroxide.
It is a further object of the present invention to provide a novel process for coating carbonate method hopcalite with sodium hydroxide.
The above objects and other objects of this invention will become more apparent after a consideration of the following detailed description taken in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE in the drawing is a partial cross section of a chemical oxygen generator utilizing the chlorine gas getter of this invention.
DETAILED DESCRIPTION
The filtering material of this invention is preferably made by initially baking out carbonate method hopcalite to drive off all water vapor and other volatile contaminants, by placing the baked out hopcalite in a solution of distilled water and a hydroxide selected from the group consisting of potassium hydroxide and sodium hydroxide, and subsequently vacuum baking the impregnated hopcalite.
The carbonate method hopcalite is initially baked out by placing the hopcalite in an appropriate sized bake out pan, the hopcalite being spread out in the pan to a level preferably not exceeding 1" in depth. The pan is then placed in an oven at a preferred temperature of 700° F.±10° F. The hopcalite is then allowed to bake out for a preferred length of time of from sixteen hours to eighteen hours. After the hopcalite has been baked out, it is allowed to cool down to room temperature.
A sodium hydroxide solution is prepared by adding sodium hydroxide to a suitable quantity of distilled water to make a solution of sodium hydroxide/distilled water in a preferred proportion of 0.15 kg/sodium hydroxide to 1 liter of water. While 0.15 kg of sodium hydroxide to 1 liter of water is preferred, concentrations as high as 0.25 kg/liter have given generally satisfactory results, and it is believed that a range of 0.1-0.3 kg/liter will give generally satisfactory results. The sodium hydroxide may be a commercial grade of pellets having a low carbonate level. The sodium hydroxide is added to the distilled water at such a rate as to maintain the solution temperature below 170° F. and to this end it may be necessary to cool the solution while the sodium hydroxide is being added. When all of the sodium hydroxide has gone into solution, the solution is then lowered to a temperature of preferably 70° F. or below. To the cooled sodium hydroxide/distilled water solution, the baked out hopcalite is then added (with mixing) in a preferred proportion of 1 kg hopcalite per liter of distilled water and at such a rate as to maintain the slurry temperature below 170° F. Once the full amount of hopcalite has been added to the solution, the slurry is then allowed to stand for preferably at least 30 minutes. After standing for 30 minutes or so, the excess sodium hydroxide solution is decanted.
The coated or impregnated hopcalite is now air dried until surface moisture is no longer visible. The air dried material is now sieved through a 10 mesh screen. Any large agglomerated particles which do not pass through the screen are broken up until they pass through the screen. The screened material is now preferably sieved through a 20 mesh screen and the fines which pass through the 20 mesh screen will not be used further. Thus, only the filter material which remains on the top of the 20 mesh screen is utilized further. The retained screened and air dried material is now loaded onto a bake out pan to a level preferably not exceeding 1" in depth. The pan is then placed in a vented oven preferably stabilized at 240° F.-260° F. and at ambient pressure and is held there for preferably 1 hour although a 2 hour bake out at ambient has also produced generally satisfactory results. After the bake out at ambient pressure, and with the temperature still being maintained at the preferred range of 240° F.-260° F., a vacuum is pulled preferably to at least 28" of mercury and the material is baked out for an additional 8-16 hours, although 16 hours is preferred until a moisture contact less than 2% is obtained preferably in the range of 1%-2%. After bake out the material is immediately placed into a sealed container from whence it can be loaded into suitable chemical oxygen generators at a later time.
The filter material of carbonate method hopcalite coated with sodium hydroxide in accordance with the above procedure have been tested against uncoated hopcalite and it has been determined that the new material outperforms untreated hopcalite in regards to chlorine filtering by a 3-4.5 margin. A bench test was performed with the hopcalite coated with sodium hydroxide in accordance with the above process and the results of the bench test are as follows:
______________________________________TEST # BREAKTHROUGH TIME______________________________________1 4 minutes, 37 seconds2 4 minutes, l2 seconds3 5 minutes, l7 seconds4 4 minutes, l6 seconds5 4 minutes, 49 seconds6 4 minutes, 33 seconds7 4 minutes, 25 seconds______________________________________
The untreated hopcalite used in the same test gave breakthrough times on the average of 1 minute. In these tests the chlorine flow was 2-3 times greater than that produced by the new chemical oxygen generators during the first 30 seconds of operation.
Bench tests were also conducted for pumice treated with various proportions of sodium hydroxide coated pumice. The following test results were obtained:
______________________________________TEST # BREAKTHROUGH TIME______________________________________1. 15 parts NaOH 100 parts pumice 3 seconds2. 10 parts NaOH 100 parts pumice 35 seconds3. 15 parts NaOH 100 parts pumice 5 seconds4. 20 parts NaOH 100 parts pumice 12 seconds5. 25 parts NaOH 100 parts pumice 20 seconds______________________________________
In view of the relatively rapid breakthrough times, pumice was not considered a suitable carrier for sodium hydroxide.
Additional bench tests were conducted utilizing activated charcoal as a chlorine scrubber. The bench tests gave an average breakthrough time of 13.45 minutes, which times are considered satisfactory.
In addition to the bench tests set forth above, functional tests were performed on the basis of the new chemical oxygen generator referred to above. A cross sectional view of a generator of the type referred to above is shown in the sole figure of the drawing and is indicated generally at 10. The chemical oxygen generator 10 is provided with a central chemical core 12 in the form of a chlorate candle which, when ignited, will produce oxygen. The chlorate candle is disposed within a housing including a generally cylindrical stainless steel shell 14. Disposed between the core and the shell 14 are concentric layers of an insulation material 16, a sleeve 18 and a preformed insulation 20. At opposed ends of the stainless steel shell are ignition head and discharge head assemblies 22, 24, respectively, which are rigidly secured to the shell 14 in an airtight relationship to complete the housing. Disposed about the insulation 16 adjacent the discharge end of the chemical oxygen generator is a cylindrical bowl member 26 having a radially outwardly extending rim 28. An intermediate portion of the rim is disposed adjacent the sleeve 18 and that portion of the rim which extends radially outwardly from the sleeve 18 is provided with a plurality of apertures 30 for the passage of gases. Disposed between the bowl 26 and the stainless steel shell 14 are a series of stacked annular filters, and specifically particulate filters 32, an oxydizing catalyst 34 such as Carulite 200, and the chlorine getters 36 which consist of carbonate method hopcalite coated with sodium hydroxide. Finally, a further particulate filter 38 is provided adjacent the inner surface of the discharge head assembly and which contacts the bottom of the bowl 26 and one of the chlorine getters 36.
Once the core 12 is ignited, the gases which are produced will flow through the insulation material 16, and then through the holes 40 in the sleeve between the head assembly 42 and rim 28 then through the annular filters 32, 34, 32, 36, 32, 36 and finally through the filter 38 and discharge valve assembly 46, the flow of gases being indicated by the various arrows in the figure.
As previously noted, when using activated charcoal as a chlorine getter in the new series of chemical oxygen generators, the charcoal became ignited and burn through of the stainless steel shell took place, the burn through occurring at the portion of the shell indicated at arrow 48. However, generators built up using 2 layers of the new filtering material of this invention at 36 completely removed all chlorine evolved. A generator in which the filter beds 34 and 36 were completely filled with untreated hopcalite has shown levels of chlorine leakage of up to 2-3 ppm.
Based upon the bench as well as the functional tests set forth above, it has been shown that the new filtering material does indeed absorb chlorine and that it absorbs the chlorine 3-41/2 times better than untreated hopcalite. It has also been shown that the filtering material produced by this process will have significantly low levels of carbon dioxide outgasing and also will not outgas chlorine at high temperature levels.
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A chlorine gas filtering material suitable for use in a high temperature oxygen environment, and a method of making the filtering material. The filtering material is prepared by impregnating a porous manganese dioxide and copper oxide hopcalite catalyst prepared by the carbonate method with sodium hydroxide. The process of making includes the steps of mixing the catalyst into a sodium hydroxide solution and then vacuum baking the impregnated catalyst for at least 8 hours, and preferably for 16 hours at a temperature of 240° F.-260° F.
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RELATED APPLICATION INFORMATION
This application is a 371 of International Application PCT/CH2011/000247 filed 19 Oct. 2011 entitled “System For Noninvasive Optical Measurements Of Physiological Properties in Tissue”, which was published in the English Language on 25 Apr. 2013, with International Publication Number WO2013/056379, the content of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to a system for noninvasive optical measurements of physiological properties in tissue. In particular, the invention relates to systems and methods comprising a light emitter emitting light of at least two different wavelengths, an optical detector, and a processor. The processor is capable of evaluating physiological properties from measurements of the optical detector.
Systems as mentioned above are widely used to evaluate and monitor physiological properties in tissue such as oxygenation of blood and heart rate (HR) in a subject and especially in a human body. In the context of this document, tissue designates a biological tissue. A biological tissue is a collection of interconnected cells that perform a similar function within a subject. Furthermore, the tissue can comprise at least a part of a vascular system where the vascular system comprises vessels (so called blood vessels). Vessels are for example arteries, capillaries or veins. When a tissue comprises blood, then the blood is always comprised in vessels of the tissue.
All known systems have the disadvantage that they are only capable of evaluating the physiological properties with a satisfactory quality in tissue of human bodies while the human body is kept at clearly defined conditions during the evaluation. These conditions or restraints require the tissue and/or the human body to be kept at rest or to be held still for most systems. These conditions or restraints may even apply to a time period before the evaluation, for example the need for resting before taking a blood pressure and/or an oximetry reading. Some other systems actively stimulate the tissue in a defined way (for example mechanically through vibration and/or application of pressure on the tissue) or require the tissue and/or body to perform clearly defined movements. During the stimulation or defined movements, the tissue and/or body have to fulfill respective conditions.
The reason for such requirements (i.e. such conditions or restraints) is that movement of the tissue or the body during the evaluation causes motion artifacts in the measurements. The same applies to the orientation of the tissue (i.e. whether the surface of the tissue is for example horizontally or vertically oriented). Changes in the orientation of the tissue lead to artifacts. These movement and/or orientation artifacts can for example be caused by a change in blood flow in the tissue or a shift in tissue layers and can be induced directly or indirectly to the tissue. Only clearly defined motions and/or orientations lead to measurements or variations of measurements which can be interpreted using the systems in the state of the art.
Systems with sensors which are attached to a fingertip and which measure light which is transmitted through the fingertip are known and widely used. These systems suffer from movement and/or orientation artifacts and other disadvantages as described above or they try to solve these issues by filtration of the measured signal after the measurement with complicated algorithms which produces a delay in the response.
It also has become known to use a mechanical sensor, such as an accelerometer, to determine whether the system is subject to motion by the user. The mechanical sensor is a sensor which measures mechanical forces, pressure and/or acceleration. Only data measured while the system is at rest are used.
A simple and reliable evaluation or monitoring of physiological properties of tissue by noninvasive optical methods is therefore not possible under real life conditions on moving subjects, especially when the subject movements occur constantly in irregular patterns. Throughout this text, subject stands for an organism and/or a body comprising the tissue which is to be measured. Especially, the subject can be a human body.
BRIEF SUMMARY OF THE INVENTION
It is an object of the invention to create a system for noninvasive optical measurements of physiological properties in tissue of the type mentioned initially, which overcomes at least partially at least one of the disadvantages mentioned above.
According to an aspect of the invention, a system for noninvasive measurements of physiological properties of tissue is provided. The system comprises an optical sensor, a mechanical sensor and a processor. The optical sensor comprises a light emitter and an optical detector. The light emitter is capable of emitting light of at least two different wavelengths and comprises at least one light source. The processor is capable of evaluating (and for example programmed to evaluate) physiological properties of the tissues from measurements of the optical and the mechanical sensor. More precisely, the processor is capable of evaluating physiological properties of venous blood by combining measurements from the mechanical sensor and the optical sensor.
The light emitter comprises at least one light source, for example at least one semiconductor light source. Such a light source could comprise a light emitting diode (LED), a super luminescent diode (SLD) and/or a laser diode (LD). One single light source can emit light at least of one wavelength, for example within a clearly defined range of a wavelength. The light emitter is capable of emitting light at least two wavelengths which are for example distinct and within a clearly defined range of a wavelengths. Optionally, a first range of a wavelengths is around an isosbestic point of oxygenated and reduced hemoglobin, and a second range of a wavelengths is away from the aforementioned isosbestic point and for example at a wavelength where the absorbance of oxygenated and reduced hemoglobin differ strongly.
An isosbestic point is a wavelength at which two chemical species (in the example above: oxygenated and reduced hemoglobin) feature the same absorbance. By measuring once at the isosbestic point and once away from it, the relative absorbance difference allows to differentiate between the two chemical species. In particular, the first wavelength can be in the infrared range of 770-830 nm (and especially 790-810 nm) and the second wavelength can be in the visible red and for example in the range of 630-690 nm (and especially 650-670 nm). An alternative isosbestic point is in a wavelength range around 568 nm, an alternative wavelength range with significant difference in light absorption between oxygenated and reduced hemoglobin is in the infrared between 900 nm and 950 nm.
Alternatively, the wavelength ranges can be selected away from isosbestic points, where absorption efficiencies of oxygenated and reduced hemoglobin are different. For wavelength ranges away from isosbestic points, it is advantageous if the relative absorbance differences between the two chemical species feature opposite signs in these wavelength ranges. For example, one range could be the aforementioned visible red range of 630-690 nm where reduced hemoglobin has a higher absorption than oxygenated hemoglobin. The second range in this example could be the aforementioned infrared range of 900-950 nm where reduced hemoglobin has a lower absorption than oxygenated hemoglobin.
The optical detector is capable of measuring the light emitted from the light emitter. In one embodiment, the optical detector can measure using temporal multiplexing which means that the optical detector can measure light emitted from the light transmitter with a first wavelength at a separate time than light emitted from the light transmitter with a second wavelength. In another embodiment, the optical detector can be capable of measuring at least two wavelengths separately and simultaneously. The optical detector can optionally have different parts which are sensitive to different ranges of wavelengths. The optical detector can for example measure light which interacted with wavelength selective elements—such as filters or reflective surfaces—after that the light interacted with the tissue. It is further possible to use more than one optical detector, for example for measuring light in different geometric configurations and/or for better statistics.
In the state of the art, it has been known to measure blood oxygenation of arterial blood by light sensor arrangements that comprise a light emitter and an optical detector for two different wavelengths: the light detected at a wavelength for example around 660 nm is the wanted signal, whereas a signal at an isosbestic point is used to subtract the influence that stems from varying hemoglobin concentrations on the wanted signal, for example due to heart pulse waves.
The invention proposes to use the measured signals of the optical sensor and the mechanical sensor in a different way. The invention takes advantage of the fact that pressure inside a venous vascular system of a subject is significantly lower than the pressure in an arterial vascular system. A vascular system comprises the venous vascular system and the arterial vascular system and encapsulates every vessel which contains blood in the subject. Veins smooth out variations in blood flow since venous vascular compliance (i.e. vascular flexibility of veins) is higher than arterial compliance (i.e. vascular flexibility of arteries). Furthermore, the venous system contains the major amount of blood.
When a pressure balance of a part of the subject or of the whole subject is disturbed by active or passive motion of the subject, by orthostatic changes i.e. changes of the subject or subject part position relative to a direction of gravitation (for example lying down of the subject or moving a part of the subject from a vertical to a horizontal position) and/or by external pressure (for example by applying additional pressure to the tissue) the part of the vascular system which is mostly affected is the venous vascular system, due to a relatively low baseline pressure of the venous vascular system and due to compliance i.e. to a relatively high flexibility of the venous vascular system. This generally leads to a relocation of venous blood which can be observed with the optical sensor. The relocation of venous blood can be used for an estimation of venous blood parameters. Contrary to this, methods known from the prior art use relocation of arterial blood due to heart beats (mostly by identifying a heart pulse wave) for an estimation of arterial blood parameters.
Using the data from the mechanical sensor in addition to the optical data, quantitative statements about the venous blood can be made. The relocation of venous blood, in contrast to relocation of arterial blood, strongly depends on parameters such as the orientation of the tissue and/or parts of the subject (for example whether an arm is positioned horizontally or vertically), muscle tension and/or pressure close to the tissue or movement of the tissue and/or parts of the subject. In addition, the venous blood oxygenation is generally unknown. Due to this, it so far was impossible to make quantitative statements about venous blood physiological properties—the state of the art sensor arrangements concentrate on the arterial blood oxygenation and heart pulse waves only.
It is an insight of the inventors of the present patent application that using a mechanical sensor in addition to the optical sensor, also properties of the venous blood can be addressed. Especially, an accelerometer, as an example for a mechanical sensor, can determine the orientation of the whole subject, a part of the subject or of the tissue and therefore of the vascular system. This allows to reproducibly utilize the relocation of venous blood due to changes of the orientation of the venous vascular system relative to the direction of gravitation caused by the motion of the subject. Similarly, a pressure sensor can account for blood volume variations in the tissue respectively in the vascular system which are caused for example by muscle contraction and/or relaxation.
Furthermore, in embodiments of the invention, movement induced signals (including orientation change induced signals) are used to purposefully address venous physiological properties. This can be done because the venous vascular system is more strongly influenced by the movements (including orientation changes) than the arterial vascular system. But whereas relocation of venous blood is an undesired effect which has to be reduced or eliminated in the prior art methods, the invention takes advantage of the relocation of venous blood. The invention therefore uses an aspect to measure physiological properties of tissue which is regarded as a disadvantage in the methods of the prior art.
The mechanical sensor can for example be integrated in the same housing with the optical sensor. The mechanical sensor can for example also be placed on the subject separately. For example, in one embodiment the mechanical sensor and the optical sensor can be attached to an upper arm of the subject with a flexible band as a single unit. In another embodiment the mechanical sensor and the optical sensor can be placed separately on a torso of the subject. A combination of several (for example different) mechanical sensors is possible and can be advantageous. The mechanical sensor is placed in such a manner that the mechanical sensor measures movement, orientation and/or pressure which can be related to the tissue which is measured with the optical sensor.
The optical sensor can be arranged in a transmission or in a reflection geometry. In transmission geometry, the tissue lies in a direct path between the light emitter and the optical detector. In transmission geometry, the path of light portions detected by the detector is mainly straight from the emitter, in addition to portions that are scattered. In reflection geometry, the light emitter and the optical detector are arranged on a first side of the tissue. The light which is emitted from the light emitter enters the tissue from the first side and exits the tissue after the interaction again towards the first side and is then measured by the optical detector that is placed aside the light emitter. Reflection geometry can be advantageous in case of a wearable system, because for transmission arrangements, firstly the light path has to be relatively short, and secondly the measurement results critically depend on the length of the light path, and this implies that the measurement is easily distorted by small movements of the system that for example is mounted on a fingertip.
The processor evaluates the physiological properties of venous blood from measurements of the optical and the mechanical sensor. The mechanical sensor measures a movement of the whole subject, of a part of the subject and/or of the tissue, an orientation of the whole subject, of a part of the subject and/or of the tissue and/or a force or a pressure applied to the whole subject, to a part of the subject or to the tissue and therefore to the vascular system. The mechanical sensor can optionally comprise an accelerometer, a pressure sensor, a strain gauge and/or other sensors. The pressure sensor can for example measure a pressure or a force applied to the tissue and/or a pressure or a force of the tissue coming from the tissue. The pressure sensor is especially capable of measuring the pressure with which the pressure sensor is pressed against the tissue. The strain gauge can for example measure changes of the dimensions of the tissue which can be related for example to a contraction or a relaxation of at least one muscle.
The processor processes the results of the measurements of the mechanical sensor. In embodiments, it may identify active periods during which the tissue is subject to a movement and/or a change in position. The measurements of the mechanical sensor allow correcting for motion artifacts and/or orientation artifacts during these active periods. In the prior art, correction for motion artifacts and/or orientation artifacts is mostly done by filtering out measurements which might include these artifacts.
As a first processing step, the processor combines the measurements of the mechanical and the optical sensors and derives the corresponding physiological properties of the venous blood in the measured tissue. The processor derives in this first step at least the venous blood relocations, which is only one of many physiological properties which can be measured. As a second processing step, the contribution of the venous blood relocations estimated in the first step is removed from the measured optical signal. The remaining optical signal after the second processing step can be used in a third processing step for further analysis to derive physiological properties of the tissue. In the third processing step, the remaining optical signal can for example be used for an analysis of arterial blood relocations originating from factors which are not directly related to motion. A factor which is not directly related to motion is for example the heart pulse wave. The physiological properties which are derived in the first and/or third processing step can be for example heart rate, heart rate variability, arterial and/or venous blood oxygenation and arterial photoplethysmographic (PPG) pulse amplitude. Blood oxygenation is the ratio of oxygenated hemoglobin concentration to total hemoglobin concentration in the blood. Blood oxygenation can be estimated for specific types and/or volumes of blood, for example for arterial blood or venous blood or specific compartments of arterial or venous blood.
The movements and/or changes in position of the tissue or parts of the tissue are not restricted to conditions in which the tissue is to be held still or is subject to defined stimulation. Rather, the physiological properties of the venous blood in this tissue can therefore be measured during regular daily routine and in everyday life. Even measurements during the sleeping periods can be performed, as the movements of a sleeping person i.e. changes in the sleeping position which normally occur irregularly during the whole sleeping period are generally sufficient to allow measurements during the movement and/or position change. The measurements can of course also be performed while the tissue is at rest or stimulated in a defined manner.
The physiological properties of venous blood are of interest because the venous blood has already interacted with the tissue. Therefore, it is possible to conclude physiological properties of the perfused tissue from the physiological properties of the venous blood. In many cases, the information about the perfused tissue can be extrapolated to gain information about a part of or about the whole subject comprising this tissue i.e. the whole organism or body comprising this tissue. One of the physiological properties of venous blood which can be measured is for example the oxygenation of venous blood (SvO 2 ). The optionally measured oxygenation of venous blood depends on different factors such as oxygenation of the corresponding arterial blood (SaO 2 ), blood flow in the perfused tissue and oxygen consumption in the perfused tissue. Once the oxygenation of the venous blood is measured, the other factors can be deduced from it.
In a tissue with low and/or constant oxygen consumption under normal conditions (such as in human skin while the subject is at rest or moderately moving), venous oxygenation can be used as a substitute of the arterial oxygenation since the difference in oxygen content i.e. the effective drop in the oxygen content from arterial to venous blood is known. The arterial oxygenation therefore can be calculated through adding the known difference to the venous oxygenation. If only trends are of interest (increase, decrease or stability of oxygenation in blood), then the venous oxygenation can be used without further calculation and still represents the trends of arterial oxygenation.
The substitute use of SvO 2 as SaO 2 can be an advantage for wearable monitoring on actively moving subjects (sportsmen, emergency workers, soldiers on the field, etc.) when the heart pulse wave is difficult to resolve on top of a background of motion-induced venous blood relocations. Without the heart pulse wave, the methods in the prior art cannot derive SaO 2 . The invention allows to derive SvO 2 and thus to calculate SaO 2 under normal conditions.
On the other hand, in tissue not under normal condition, for example when oxygen supply of the subject respectively the body is compromised (e.g. due to blood loss) the blood flow to the less vital tissues (such as skin, subcutaneous layers, muscle, gastrointestinal tract) is reduced and thus the resulting venous oxygen content in such organs is significantly reduced. Thus the SvO 2 in such organs measured with the proposed method can be a sensitive marker of such events. Significant changes of SvO 2 can therefore be used to identify a transition from a tissue or a whole body under normal to a tissue or a whole body not under normal condition.
As an option, relative concentrations of one or more derivatives of hemoglobin other than SvO 2 can be investigated in the venous blood. For example, carboxyhemoglobin, methemoglobin and/or fetal hemoglobin can be investigated. These derivatives have specific absorption spectra in the visible and/or infrared regions and thus can be detected optically. The advantage of using the venous blood for the estimation of the derivatives other than oxyHb is that the content of the derivatives other than oxyHb in venous blood is generally similar to the content of the derivatives in arterial blood, while the venous blood volume variations caused by motion are higher (i.e. venous blood relocations caused by motion are more pronounced) than the changes induced by the heart pulse wave in the arterial volume. Thus the venous blood can potentially provide a higher signal to noise ratio than the arterial blood for such measurements. For the measurements of hemoglobin derivatives other than oxygenated hemoglobin, additional probing wavelengths can be introduced in order to allow for discrimination of different hemoglobin derivatives due to their specific absorption spectra.
Physiological properties of venous blood can be combined with physiological properties of arterial blood to derive additional parameters. Different methods to measure the physiological properties of arterial blood are known and described in the state of the art. It is possible to measure the physiological properties of arterial blood using the system described above (or only parts of it, for example by using the sensors, the data and/or the processor). In addition or as an alternative, is also possible to measure the physiological properties of arterial blood separately and independently.
For example, when SaO 2 , SvO 2 and the blood flow are known, tissue oxygen consumption can be estimated according to Fick's principle as a product of the blood flow and oxygenation difference between SaO 2 and SvO 2 . The blood flow can for example be derived from a PPG amplitude estimated with a system according to the invention or with alternative methods using the system according to the invention and/or other systems. Alternative methods using other systems are for example Laser Doppler Flowmetry (LDF) or measurements using a heat dissipation sensor.
Therefore, the measurement of physiological properties of venous blood additionally allows a better insight and more precise measurements of physiological properties of the tissue. But also the oxygenation of the arterial blood can be calculated with the use of the oxygenation of the venous blood in a more accurate and precise way since the measurement can account for changes in movement, position, pressure and/or perfusion. In general, the invention allows measurements of physiological properties of tissue using a non-invasive method suitable for real time application.
As an option, the processor is capable of evaluating a physiological property of venous blood using movement of blood in the tissue caused by natural movement of the tissue.
The physiological properties of venous and arterial blood and especially the oxygenation of venous and arterial blood can optionally be separated by the processor by using natural movement of the tissue which causes the blood in the tissue to move. The processor evaluates the measurements of the mechanical sensor and identifies movement of the tissue. The tissue movement can be induced by natural movements which occur in everyday life. This is called the indirect method.
The indirect method uses natural movement of blood i.e. relocation of the blood in the tissue due to natural movement of the tissue.
In addition or as an alternative, the tissue movement can also be induced by defined motions and/or through external stimulation. This is called the direct method. The direct method forces blood movement in the tissue, for example through arterial or venous occlusions or defined physical exercise for patients. A typical example for an external stimulation is a tilt table test (also called upright tilt testing), where the subject is attached to a table. Measurements of the subject are then performed while the table with the attached subject changes position from vertically oriented to horizontally oriented and vice versa.
One advantage of the indirect method is the possibility to measure the physiological properties of venous and arterial blood in real life conditions and without any restraints or conditions. This is more convenient than the direct method since the subject does not have to follow restrictions. Furthermore, the measurements can be performed in the usual environment of the subject. A patient i.e. a human being for example can be monitored during work, leisure time and/or while sleeping and is able to follow his usual and normal daily routine.
To identify movement of the tissue and/or within the tissue (for example movement of different tissue layers relative to each other), the processor evaluates the measurements of the mechanical sensor. The processor optionally can set an upper and/or lower threshold of movement of the tissue to define a range of movement of the tissue in which the processor evaluates the measurements of the optical and/or mechanical sensor. The processor is capable of evaluating the data of the optical and/or mechanical sensor in respect to the identified movement of the tissue.
As a further option, the system according to the invention is capable of detecting variations of lighting conditions and subtracting these variations from the measured optical signals. This is for example of special importance for wearable systems where the subject and the system can be exposed to different lighting conditions as during real-life activities of a human subject, especially when for example ambient lighting conditions vary strongly.
The lighting condition variations can for example be measured with a detector which is also used for a measurement of tissue attenuation. In such a case, the light emitter of the system should be disabled or an intensity of the emitted light should be modified in a predefined way during measurements of the lighting condition. Alternatively, lighting conditions can be monitored with at least one dedicated sensor which is for example not sensitive to the light from the emitter. The dedicated sensor for measurements of lighting conditions can optionally also be used for other measurements. In the case of a dedicated sensor which is not sensitive to the light from the emitter, the measurements of the lighting conditions can be performed simultaneously to the measurements of the system, which is of an advantage in the case of rapidly changing lighting conditions.
As a further option, the processor is capable of recognizing variations of the optical signal related to a heart pulse wave respectively to a heart beat and is capable of including these variations in the evaluation of physiological properties of the venous and/or arterial blood.
The processor is optionally capable of evaluating the measurements of the optical sensor and/or the mechanical sensor to estimate a heart rate and/or a heart pulse wave parameter such as phase, amplitude, transit time and other characteristics of a heart pulse wave. This can be performed for example with a photoplethysmographic approach, which is known in the state of the art. In the photoplethysmographic approach, changes in light attenuation which are associated with cyclical variations in concentration and orientation of red blood cells in a sampled microvascular volume are measured. The processor is capable of extracting a frequency and a phase of a heart cycle as well as other parameters of these cyclical variations with known algorithms.
The estimated heart rate and/or heart pulse wave parameter is then used to interpret the measurements of the optical sensor further. The heart rate and/or heart pulse wave parameter can show specific signal changes in the measured signals. With an estimated heart rate and/or heart pulse wave parameter these specific signal changes can be identified. If needed, the specific signal changes can be eliminated.
The measurements of the optical and/or mechanical sensor can also be interpreted specifically during at least a part of the time intervals while the specific signal changes of the heart rate and/or a heart pulse wave parameter occur. The measurements of the optical and/or mechanical sensor can for example be interpreted specifically only during a blood pressure increase which occurs during a heart beat respectively on the front of a heart pulse wave which is identified for example by a specific increase of the amplitude of the heart pulse wave. Through the estimation of the heart rate and/or a heart pulse wave parameter and the inclusion of this estimated heart rate and/or a heart pulse wave parameter in the evaluation of the physiological properties of venous and/or arterial blood through the processor, the measurements are more precise than without an estimation of such a heart rate and/or a heart pulse wave parameter.
In some cases and/or under certain conditions, the evaluation of the measurements is not possible at all without the estimation of the heart rate and/or a heart pulse wave parameter. In order to be able to evaluate a parameter of the heart pulse wave a sampling frequency of the optical signals should be at least 10 times higher than a frequency of the heart cycle. This results typically in the sampling frequency of at least 20 Hz.
As a further option, the light emitter is capable of emitting light of a third wavelength (in particular light in a green wavelength range) and the optical detector is capable of measuring the light of the third wavelength.
Generally, the third wavelength is preferably at an isosbestic point or alternatively at a point with a strong contrast between oxygenated and reduced hemoglobin signals.
In embodiments, where the first and second wavelength ranges are in the infrared and in the red part of the optical spectrum, respectively, the third wavelength may be in a green part of the spectrum.
Then, the range of the optionally emitted third wavelength is a green wavelength range (i.e. green range) which is in particular 500-600 nm and especially 540-570 nm. As an example, the third wavelength is 568 nm which is an isosbestic point for of oxygenated and reduced hemoglobin. Blood exhibits much higher absorption efficiency in the green range than in the red or the infrared ranges. Green light is thus very sensitive to variations of the amount of blood in the tissue. Measurements with green light are advantageously performed in reflection geometry. Optionally, the measurements with the third wavelength can be performed with a separate optical sensor (or separate optical detector) optimized for this particular wavelength. Such sensor (or detector) can potentially have a different geometry and different characteristic dimensions.
At an isosbestic point of oxygenated and reduced hemoglobin, both kinds of hemoglobin contribute the same signal intensity to the measured total signal. Therefore, measurements at such an isosbestic point represent measurements the total hemoglobin concentration and are not influenced by different and/or changing oxygenation of the hemoglobin. Thus such measurements at an isosbestic point represent indirectly measurements of the total blood perfusion. Measurements at isosbestic points may for example be used for measurements of a heart rate, and/or a heart pulse wave parameter. The heart rate and/or a heart pulse wave parameter can be used to ameliorate the measurements of the physiological properties of the tissue. For example, heart pulse wave effects and/or movement artifacts can be discriminated to ameliorate the measurements. Movement artifacts can be identified from characteristic changes in the heart rate and/or a heart pulse wave parameter.
In particular, measurements with light at an isosbestic point in the green range are suitable for measurements of the heart rate and/or a heart pulse wave parameter and/or other physiological properties of blood because of the high absorbance of blood for light in the green range and the resulting high sensitivity to this light. Especially, a signal measured in the green range may be indicative of the blood physiological properties of the uppermost tissue layers. The measured signal of the third wavelength is for example the total intensity of the third wavelength measured with the optical detector.
As a further option, the processor is capable of using a dynamic light scattering (DLS) technique to detect the heart rate and/or at least one heart pulse wave parameter.
Dynamic light scattering (DLS) techniques as for example laser Doppler or speckle correlometry allow the measurement of dynamics of material which scatters light, for example of a tissue matrix, fluids and/or particles in fluids and especially the dynamics of red blood cells in blood. DLS uses statistical analysis of intensity fluctuations of coherent light scattered from such material to derive parameters of dynamics of such material. By investigating statistical properties of temporal fluctuation of scattered coherent light it is possible to detect for example the heart pulse wave as time intervals with increased dynamics of the red blood cells. Higher dynamics can lead to shorter correlation times, to a broader spectrum of fluctuations or to a reduced contrast of time-integrated speckles. DLS techniques can be applied at low cost and in a noninvasive manner. One embodiment using the DLS technique for an estimation of the heart rate features at least one additional laser diode. In another embodiment, LEDs are replaced with laser diodes The DLS techniques can be used to recognize variations of the movement of blood instead, in combination with and/or parallel to measurements with green light.
As a further option, the system comprises at least two optical detectors for spatially resolved measurements.
The tissue might be heterogeneous, and different parts of the tissue might exhibit different behaviour and/or physiological properties. At least two optical detectors allow optical measurements which are spatially resolved. Each optical detector is capable of receiving the light from at least one light emitter for at least a short period of time. In one example, one light emitter emits light which is received by the two optical detectors simultaneously and continuously during the measurement. The spatially resolved measurements measure one or more specific parts of the tissue. This allows more precise measurements and reduces possible problems which occur when the optical detectors measure arbitrary parts of the tissue and/or measure an average value of many different parts of the tissue. Optionally, the same specific part of the tissue is measured repetitively in a short and/or long time period.
Alternatively, detectors with spatially addressable elements can be utilized, e.g. a charge coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) based camera detectors. The spatially addressable elements are spatially separated and independently functioning (sub-)detectors within such a detector comprising the addressable elements. In other words, such a detector comprises a multitude of small (sub-)detectors which measure independently of each other and are spatially separated.
The spatially resolved measurement can alternatively or complementary also be performed in other configurations than with two optical detectors, for example with only one sensor and at least two light sources, where the at least two light sources emit light alternatively and where they are spatially separated. In this way, the light emitted by the at least two light sources interacts in different ways with the tissue and/or interacts with at least partially different parts of the tissue before it is measured by the one or more optical detectors.
As a further option, the light emitter and the optical detector are arranged in a reflection geometry and are located close to each other.
The arrangement of the light emitter and the optical detector in reflection geometry and close to each other allow a measurement of only the upper layers of the tissue, since the light which interacts only with the upper layers of the tissue contributes more intensity to the total intensity of the measured signal. With the reflection geometry, light which penetrates to deeper layers of the tissue suffers in general from more attenuation, absorption and/or scattering and is therefore less intense than light which penetrates only the upper layers of the tissue.
In the case of measurements of skin, the upper layers which are measured correspond mainly to dermal layers. Besides that the light emitter and the optical detector are located close to each other, additional other factors can allow a measurement of only the upper layers of the tissue. One additional factor is for example length of the measurements i.e. a temporal detection limit. Temporal detection limits can ensure that the detector measures only a spatially selected part of the tissue. When measurements are for example much shorter than the timescale of the disturbing parameters, then the disturbing parameters change total values of measured signal but not relative changes of the measured signal and the disturbing parameters are therefore suppressed for measurements of relative changes of the signal. On the other hand, very short measurements can lead to low precision of a measured signal due to lack of statistics or even can be impossible when the measurement length is at or below a limit of detection. The length of the measurement also depends of the intensity of the emitted light. The higher the intensity of the emitted light, the shorter a measurement can be for the same statistics.
That the light emitter and the optical detector are located close to each other means in the context of this document that the light emitter emits light in a distance of 0.1-10 mm, especially 0.5 mm-4 mm from the optical detector.
With the light emitter and the optical detector are located close to each other, the sampling volume of the tissue is furthermore localized i.e. the measured part of the tissue is limited in size and its position known. The advantage of measurements constrained to the upper layers of the tissue are a lower sensitivity to tissue movement of lower layers, relative movements between different layers and/or other factors as mechanical influences or motion artifacts. This is also advantageous to avoid or minimize motion artifacts.
In one embodiment, the light emitter and the optical detector are located close to each other and the optical detector comprises a multitude of (sub-)detectors which measure independently of each other and which are spatially separated. This is for example the case for a segmented photodiode or a camera. Each of the (sub-)detectors i.e. segments can be located with a different distance to the light emitter, which results in a graded separation. Through measurements with graded separation and an according choice and/or treatment of the measured signals, measurement of only the upper layers of the tissue can be ensured.
As another option, the system comprises a dielectric sensor which allows the system to discriminate different tissue components and volume fractions.
The dielectric sensor allows the system to discriminate different tissue components such as blood, blood cells and tissue fluids and allows for an estimation of their corresponding volume fractions. When such information is accessible, the processor can include it in the evaluation of the measurements of the mechanical and/or optical detector and the estimation of the physiological properties of the tissue become more precise than without such information. But even without being used in the evaluation of the measurements of the mechanical and/or optical detector, this information can be combined with the measurement results to provide additional parameters of interest and to allow further analysis of the state and the properties of the tissue. Different types of tissue liquids and/or volume fractions can alternatively also be estimated by for example an additional optical detector for the water content, for example in the infrared spectral range, instead of a dielectric sensor.
Optionally, effects of the movement of the tissue and/or the subject can be characterized with different imaging modalities which are able to continuously monitor tissue morphology. Such modalities include ultrasound techniques, optical coherence tomography and microscopy techniques. Changes in structure and/or dimension of the vascular system observed with such modalities can be related to the measurements of the optical sensor in a way similar to a way to relate the measurements of the mechanical sensor to the measurements of the optical sensor as described in the paragraphs above. The corresponding blood parameters can be extracted as described in the way to relate measurements of the mechanical sensor to the measurements of the optical sensor.
According to another aspect of the invention, a method for measurements of physiological properties of tissue is provided. This method is particularly applicable in a system as described in the paragraphs above and comprises the steps: emitting light with at least two wavelengths, optically measuring the emitted light after the emitted light interacted with the tissue, performing a mechanical measurement of the tissue during and/or closely synchronized with the step of measuring optically, evaluating physiological properties of the tissue from the optical and the mechanical measurements. The method is characterized in that in the step of evaluating, a physiological property of venous blood is evaluated.
This method can optionally comprise that the step of measuring optically comprises performing at least two optical measurements simultaneously for spatially resolved measurements. As another option, in the step of measuring optically the light is penetrating only upper layers of the tissue. The advantages and further options of this method and alternatives to some options are described in the paragraphs above. Features of the method claims may be combined with features of the device (i.e. system) claims and vice versa.
According to another aspect of the invention, a system for noninvasive measurements of physiological properties of tissue is provided. This system comprises an optical sensor and a processor which is capable of evaluating physiological properties from measurements of the optical sensor. The optical sensor comprises a light emitter, and an optical detector. The light emitter is capable of emitting light of at least three different wavelengths and comprises at least one light source. This system is characterized in that the processor is capable of evaluating separate physiological properties of venous and arterial blood. Compared to the system described in the paragraphs above, this system does not necessarily but only optionally feature a mechanical sensor. However, all other advantages and options (and alternatives to the options) for the system described in the paragraphs above are also valid for and applicable to this system.
According to another aspect of the invention, a system for noninvasive measurements of physiological properties of tissue is provided. This system comprises an optical sensor and a processor which is capable of evaluating physiological properties from measurements of the optical sensor. The optical sensor comprises a light emitter and an optical detector. The light emitter is capable of emitting light of at least two different wavelengths and comprises at least one light source. This system is characterized in that the light emitter and the optical detector are arranged in a reflection geometry and are located close to each other in order to measure blood movement only in upper layers of the tissue, and that the processor may be capable of evaluating separate physiological properties of venous and arterial blood. Compared to the system described in the paragraphs above the paragraphs describing the method, this system does not necessarily, but only optionally feature a mechanical sensor and/or a third light source. However, all other advantages and options (and alternatives to the options) for the system described in the paragraphs above are also valid for and applicable to this system.
The invention has a wide range of potential applications within for example a medical environment, life-style physiological monitoring, safety physiological monitoring and/or research applications. The invention could for example be applied in (but is not limited to) the field of medical applications, in the case of cardiac problems, apnea/hypopnea, in sleep labs, for general monitoring of elderly people, independent living, smart home concepts, for life-style/physiological monitoring, for sleep monitoring, self-tracking, amateur sport and fitness, professional athletes (especially for an optimization of training), for dangerous professions, drivers, air controllers and operators of machines (to detect for example drowsiness), for stress and/or arousal detection and for energy expenditure monitoring. Furthermore, the invention could be applied in research, in clinical studies for example for drug development, for sleep studies and cardiovascular disease research.
BRIEF DESCRIPTION OF THE DRAWINGS
The subject matter of the invention will be explained in more detail in the following text with reference to exemplary embodiments which are illustrated in the attached drawings, in which:
FIG. 1 shows a graph with the absorbance of oxygenated and reduced hemoglobin in dependence of the wavelength of light;
FIG. 2 schematically shows an effect of different orientations of the tissue on the intensity of measured light in reflection geometry;
FIG. 3 schematically shows a superposition of arterial and venous blood volume changes and a way to separate them in optical measurements;
FIG. 4 schematically shows a cross section of an embodiment of the invention as a side view;
FIG. 5 shows a schematic representation of light propagation in skin;
FIG. 6 shows a graph of an attenuation of infrared light plotted against an attenuation of red light during different exercises;
FIG. 7 shows a measurement of oxygenation changes during exercise;
FIG. 8 shows a graph with an example of a venous oxygenation trace for one day and in another graph a corresponding trace of an acceleration sensor;
FIG. 9 shows in an upper graph the venous and arterial oxygenation over a day;
FIG. 10 shows a graph with the absorbance of different derivatives of hemoglobin in dependence of the wavelength of light.
The reference symbols used in the drawings, and their meanings, are listed in summary form in the list of reference symbols. In principle, identical parts are provided with the same reference symbols in the figures.
DETAILED DESCRIPTION
FIG. 1 schematically shows a graph with the absorbance of oxygenated hemoglobin (oxyHb) and reduced hemoglobin (rHb) in dependence of the wavelength of light. The vertical axis s of the graph represents the absorbance i.e. a molar extinction coefficient [cm −1 /M] which measures how strongly chemical species (in this case oxyHb and rHb) absorb light. The horizontal axis λ of the graph represents the wavelength [nm] of the light. Vertical dotted lines represent wavelengths chosen for one embodiment as described above. Two of these wavelengths are isosbestic points: a green isosbestic point at 568 nm and an infrared isosbestic point at 798 nm. Isosbestic points correspond to a wavelength where oxyHb and rHb exhibit the same absorbance. A red wavelength at 660 nm represents a point with a large difference i.e. a large contrast in the absorbance of oxyHb and rHb.
A difference in the absorbance of oxygenated and reduced hemoglobin as for example in the red range at 660 nm can be used for measurements of the relative amount of oxygen bound to hemoglobin. Typically at least two wavelengths with significantly different absorption efficiencies of rHb and oxyHb can provide this information. However, the presence of tissue components with unknown attenuation makes a quantitative interpretation of the measurements difficult.
In a scope of pulse oximetry as known in the state of the art, relative temporal variations of the measured signal intensity (and therefore an according attenuation in the tissue) caused by the heart pulse wave are measured with at least two wavelengths. The ratio of variations of the measured signal at all measured wavelengths can be then related to arterial blood oxygenation since a heart pulse wave is assumed to be present exclusively in the arterial vascular system. Contrary to this, the invention uses relative temporal variations of measured signal intensity due to relocations of venous blood (which are for example caused by motion of the tissue and/or the subject) for the estimation of the venous blood oxygenation. The venous blood oxygenation is estimated from relocations of venous blood (for example caused by movement of the tissue and/or the subject) while the arterial blood oxygenation is estimated from relocations of the arterial blood during the heart pulse wave which is caused by the heart beat.
FIG. 1 shows furthermore, that the absorbance of hemoglobin at the green isosbestic point is much higher than at the infrared isosbestic point. Thus the green light is more sensitivity to variations of a hemoglobin content. Generally, light at wavelength around the green isosbestic point have been found to provide a suitable reference signal in reflection measurements. Light at the green isosbestic point is therefore very well suited to be used for an evaluation of physiological properties of the tissue which are related to arterial blood, for example to estimate the heart rate, the heart rate variability and/or at least one heart pulse wave parameter which can be used for the enhancement of measurements on other wavelengths.
FIG. 2 schematically illustrates an effect of different orientations of the measured tissue respectively the part of the subject comprising the tissue on the intensity of measured light in reflection geometry. A horizontal axis t in FIG. 2 represents time, a left vertical axis I represents intensity of light measured by an optical detector in a reflection geometry and a right vertical axis Acc Y represents acceleration in direction y measured by the mechanical sensor. These measurements are performed by a device 1 using a method and/or comprising an embodiment of a system according to the invention described above which include a mechanical sensor. The direction y is fixed relative to the device 1 . Such a device 1 can be attached to an upper arm as shown in FIG. 2 . Device 1 can be attached at other places, for example at the forearm, the wrists, the torso, the upper thighs and around the shins Device 1 features a mechanical sensor which is capable of measuring acceleration in direction y which in FIG. 2 is designated by an arrow.
On the left half of FIG. 2 , the upper arm is positioned horizontally. In an idealised case the accelerator measures zero acceleration signal in direction of y, and the intensity I of light which is measured by the optical detector of device 1 is relatively high. The undulations of the measured intensity of light are caused by the heart pulse wave. When the upper arm is positioned vertically and downwards, as shown in the right half of FIG. 2 , the amount of venous blood in the tissue probed by the sensor is increasing due to gravitation. The blood relocation is specific to the venous vascular system due to a significantly lower pressure of the venous vascular system compared with the arterial vascular system: the arterial blood flow with relatively high pressure in the arterial vascular system is not significantly changed by the relatively small effect of gravitation. But compared to the relatively low pressure of the venous vascular system, the effect of gravitations is relatively large, and the venous blood flow is significantly changed.
An increase of a venous blood volume when the upper arm is positioned vertically leads to an increase of absorbance of light (respectively to an increase of attenuation of light) which is interacting with the tissue and correspondingly to a decrease of the intensity I of the measured light. The accelerometer measures a gravitational acceleration in direction of y when the upper arm is positioned vertically. In short, the orientation of the tissue and/or the subject does influence the measured signal, and information related to the orientation of the tissue and/or the subject can be used to evaluate measurements which are performed with tissue at different and/or varying orientation.
FIG. 2 also illustrates that the measured signal comprises contributions of the arterial blood volume variations caused by the heart pulse wave and that the contribution of the venous blood relocations are caused by motion which means in this case a change of the orientation of the upper arm.
Device 1 as shown in FIG. 2 is an example of an embodiment of a system according to the invention described above. Device 1 is wearable, especially continuously wearable. Wearable means that device 1 is lightweight, unobtrusive, portable and can be worn without great discomfort. Preferably, device 1 is a standalone device and is not depending on other devices during the measurements. It is, however, not excluded that the device 1 is in permanent or non-permanent communication with other devices, attached to the subject, placed independently of the subject or carried by a subject.
FIG. 3 schematically shows a superposition of arterial and venous blood volume changes and a way to separate them in optical measurements. From left to right, FIG. 3 shows separate initial arterial attenuation signals 30 . 1 , 30 . 2 from arterial blood volume changes due to heart beat respectively the heart pulse waves and initial venous attenuation signals 31 . 1 , 31 . 2 from venous blood volume changes due to activity, measured optical signals 32 . 1 , 32 . 2 , an accelerometer signal 33 and separated arterial portion signals 34 . 1 , 34 . 2 and venous portion signals 35 . 1 , 35 . 2 . The initial arterial attenuation signals 30 . 1 , 30 . 2 and the initial venous attenuation signals 31 . 1 , 31 . 2 are a priori unknown. All signals except the accelerometer signal 33 in FIG. 3 are illustrated for two wavelengths: the signals with solid lines and the designation ending 0 . 1 represent a signal for a wavelength in the infrared range, and the signals with broken lines and the designation ending 0 . 2 represent a signal for a wavelength in the red range.
The measured optical signals 32 . 1 and 32 . 2 are a superimposed result of initial arterial attenuation signals 30 . 1 , 30 . 2 and the initial venous attenuation signals 31 . 1 , 31 . 2 . In a simplest case in order to be able to separate signal portions from the arterial and from the venous blood, the accelerometer signal 33 is—after suitable calibration and/or sensitivity correction—subtracted from the measured signals 32 . 1 , 32 . 2 . The subtraction of the accelerometer signal 33 corrects for the influence of venous blood and results in arterial portion signals 34 . 1 , 34 . 2 which represent arterial properties. A subtraction of the arterial portion signals 34 . 1 , 34 . 2 from the measured signals 32 . 1 , 32 . 2 then may provide venous portion signals 35 . 1 , 35 . 2 representing properties of venous blood.
It is also possible to use more sophisticated approaches than a mere subtraction. Especially, the accelerometer signal may be statistically correlated with the measured optical signals. Signal portions of the optical signals that are correlated with the accelerometer tend to be of a venous origin, whereas uncorrelated signal portions are more of an arterial origin. Even more in general, other suitable algorithms that have the three signals as input and physiological properties as output are feasible. For example, it is possible to apply multivariate analysis (and multiple regression analysis in particular) to investigate the relation of intensity variations of red and infrared light which are correlated with the measurements of the mechanical sensor. Variations of the frequency of the heart rate not associated with mechanical movements can be attributed to the heart pulse wave and can be used for the estimation of physiological properties of arterial blood. Thus from the relation of the arterial portion signals 34 . 1 , 34 . 2 and the venous portion signals 35 . 1 , 35 . 2 , physiological properties of the arterial respectively venous blood can be deduced.
FIG. 4 schematically shows a cross section of one possible embodiment of the invention as a side view. The system 40 is comprised in the device 1 . The system 40 comprises a frame 41 with three compartments 42 . 1 - 42 . 3 : two light detector compartments 42 . 1 , 42 . 3 and one light emitter compartment 42 . 2 between the light detector compartments 42 . 1 , 42 . 3 . The compartments 42 . 1 - 42 . 3 are formed on sides and top by the frame 40 . At the bottom, the compartments 42 . 1 - 42 . 3 are closed by a glass plate 43 . An acceleration sensor 44 is attached to the frame 41 such as all movements which affect the frame 41 and its content are measured by the acceleration sensor 44 . Furthermore, the acceleration sensor 44 is capable of measuring the orientation of the frame 41 . Frame 41 and acceleration sensor 44 are comprised in a substrate 45 .
The light emitter compartment 42 . 2 is arranged between the two light detector compartments 42 . 1 and 42 . 3 and comprises the light emitter. The light emitter comprises three LEDs 46 . 1 , 46 . 2 , 46 . 3 which emit light at three different wavelengths and which are attached to the top of the light emitter compartment 42 . 2 . A wavelength of light emitted by a first LED 46 . 1 is in the red range which is between isosbestic points and a wavelength of light emitted by a second LED 46 . 2 is in the infrared range at an isosbestic point. A third LED 46 . 3 emits light of the third wavelength close to an isosbestic point in the green range. Measured signals of the red and infrared (i.e. first and second) LEDs 46 . 1 and 46 . 2 are used for an estimation of the ratio of oxygenated haemoglobin, while a measured signal from the third, green LED 46 . 3 is used for the estimation of heart rate. The heart rate is used for the enhancement of the measured signals of the other wavelengths (red and infrared).
The light emitter compartment 42 . 2 also comprises two monitoring photodiodes 47 . 1 , 47 . 2 which are either arranged in direct line of sight to the LEDs 46 . 1 , 46 . 2 and 46 . 3 or as shown in FIG. 4 at the side of the LEDs 46 . 1 , 46 . 2 and 46 . 3 . The first and second monitoring photodiodes 47 . 1 , 47 . 2 receive light emitted from the LEDs 46 . 1 , 46 . 2 , 46 . 3 through reflective elements 50 . 1 , 50 . 2 . Signals of both monitoring photodiodes 47 . 1 , 47 . 2 are combined and they act as one single multicomponent detector. Alternatively, different monitoring photo diodes could measure different wavelengths in another embodiment of the invention. The combined measured signal of the monitoring diodes 47 . 1 , 47 . 2 is used as reference signal accounting for intensity variations of the light emitted by the light emitter and more specifically by the LEDs 46 . 1 , 46 . 2 , 46 . 3 . They may in addition or as an alternative be used for calibration purposes.
A first light sensor compartment 42 . 1 comprises a first signal photodiode 48 . 1 and a second light sensor compartment 42 . 3 comprises a second signal photodiode 48 . 2 . The signal photodiodes 48 . 1 , 48 . 2 are attached to the frame 41 in their compartments 42 . 1 , 42 . 3 . In analogy to the monitoring photodiodes 47 . 1 , 47 . 2 , the signals of photo diodes 48 . 1 , 48 . 2 are combined and both act as a single multicomponent detector. Alternatively, different photo diodes could measure different wavelengths in another embodiment of the invention. Light emitted by the LEDs 46 . 1 , 46 . 2 , 46 . 3 is partly reflected by the reflective elements 50 . 1 , 50 . 2 and partly passes a gap between the reflective elements 50 . 1 , 50 . 2 , as illustrated by an exemplary photon path 49 . The light passes a second gap which is similar to the gap between the reflective elements 50 . 1 , 50 . 2 and which is formed by the frame 41 . Both gaps collimate the emitted light beam. After having passed the second gap, the light passes the glass 43 downwards and interacts with tissue 51 , which is in direct contact with the glass 43 .
After interaction of the emitted light with the tissue and diffuse propagation of the light in the tissue, some part of light passes (for example along a photon path 49 ) the glass 43 upwards and enters the light sensor compartments 42 . 1 . In this light sensor compartment 42 . 1 , the light is received and measured by the signal photodiode 48 . 1 . Other photon paths will lead to the other sensor compartment 42 . 3 , in analogy to the depicted photon path; the number of scattering/reflection events can be anything greater than or equal to one.
In this embodiment the measurements are to be performed with temporal multiplexing, i.e. the measurement is performed with one wavelength at a time. For example, firstly the repetitive sampling of green light can be performed when the third LED 46 . 3 is activated and an analog-digital converter (ADC) makes a repetitive simultaneous sampling of the intensity detected by the signal diodes 48 . 1 , 48 . 2 and the monitoring photodiodes 47 . 1 , 47 . 2 . Such a sampling of light in the green range can be called a green block measurement. Furthermore, in order to allow for a correction for variations of ambient light, a periodical sampling of intensity with deactivated LEDs 46 . 1 , 46 . 2 , 46 . 3 can be performed. In a simplest case, the LEDs 46 . 1 , 46 . 2 , 46 . 3 can be set to emit light with a 50% duty cycle and the ADC measurements made while the LEDs 46 . 1 , 46 . 2 , 46 . 3 are not emitting light are used to correct the measured signal i.e. the light intensity detected while the LEDs 46 . 1 , 46 . 2 , 46 . 3 are emitting light to account for ambient light variations. The corrected signal can then be further used for the estimation of the heart rate and other physiological parameters.
Since signals measured in the red and infrared range are used in combination for the estimation of physiological parameters of the tissue and especially of physiological parameters of blood, their sampling should be performed in a sequential and interleaved fashion and form a measurement block. In a simplest case, the first and second LEDs 46 . 1 , 46 . 2 (emitting light in the red and infrared range) are switched on and off consecutively and alternating while the ADC sampling of the corresponding signals is performed. This means that only either the first LED 46 . 1 or the second LED 46 . 2 is emitting light at any time and that the first LED 46 . 1 is switched off when the second LED 46 . 2 is switched on and vice versa. The measurements with the accelerometer sensor 44 are performed in parallel to the optical sampling i.e. to the sampling of the signal photodiodes 48 . 1 , 48 . 2 . Furthermore, the ambient light can be sampled periodically with all LEDs 46 . 1 , 46 . 2 , 46 . 3 switched off. The ambient light signal is furthermore used to correct the signals measured in the red and infrared range for varying ambient light conditions.
With the embodiment shown in FIG. 4 , the sampling of a green block of measurements (i.e. sampling of measurements of light in the green range as described above) and a red/infrared block (i.e. sampling of measurements of light in the red and infrared range as described above) is performed sequentially.
Alternatively, the sampling of all three wavelengths as well as ambient light measurements can be performed in one single block, when the green, red, infrared and ambient light channels are sampled sequentially and repeatedly. In this case the measurement system should be able to sample with a sampling frequency which is at least four times higher than the minimum sampling frequency for a case of sampling of a single channel. The minimum sampling frequency for sampling of a single channel is typically 20 Hz.
If the system incorporates two or more individually operated optical sensors, sampling of the green channels and red/infrared channels can be performed in parallel. This increases the performance of the filtering method of signals in the red and infrared range with the heart rate obtained from the green measurements, since both measurements are performed at the same time.
FIG. 5 shows a schematic illustration of light propagation in human skin 60 . The human skin 60 comprises different layers 61 . 1 - 61 . 4 , and light can propagate through different layers 61 . 1 - 61 . 4 . FIG. 5 shows an example of four layers 61 . 1 - 61 . 4 , and these four layers 61 . 1 - 61 . 4 are the layers closest to the skin surface. The illustrated photon path 62 in reflection geometry interferes with three layers 61 . 1 - 61 . 3 , more specifically with the three layers 61 . 1 - 61 . 3 closest to the skin surface. Solid lines designate the boundaries of statistically most probable paths which are likely to be taken by the photons emitted from S and detected at D.
Statistically, the proportion of photon paths that penetrate deeply in the tissue (i.e. the skin 60 ) compared to photon paths that do not penetrate deeply depends on a distance r between a light emitter S (i.e. a source) and an optical detector D in reflection geometry. The longer the distance r, the larger the portion of received photons that have penetrated deeply. Thus, the longer the distance r (in reflection geometry), the larger the portion of photons that have been scattered by different tissue layers. In the event of motion of the subject, the motion causes distortions, because the different layers will be displaced with respect to each other. With a smaller source-detector distance r the propagation will be limited to the upper layers of the skin (as shown for example by the photon path 62 in the upper three skin layers 61 . 1 - 61 . 3 ), and thus the sensitivity to motion artefacts caused by the skin motion will be decreased
The measurements of FIGS. 6-9 were performed with a system 40 as described in FIG. 4 attached to the upper arm as illustrated in FIG. 2 .
FIG. 6 shows in a graph an attenuation of red light during different exercises plotted against an attenuation of infrared light measured simultaneously. In FIG. 6 , the horizontal axis Δ A ( 798 ) designates changes in attenuation of infrared light, and the vertical axis Δ A ( 660 ) designates changes in attenuation of red light. Both attenuations are measured with a device according to the invention which means that the attenuations are deduced from the calculated venous blood signal (shown as venous portion signals 35 . 1 , 35 . 2 in FIG. 3 ). There is a clearly visible relation of changes in the attenuations of infrared and red light during exercises, visualised through a broken line. Each symbol shape represents measurements of a different subject i.e. of a different human volunteer. From a slope of the broken line, an averaged oxygenation ratio of 0.87 can be deduced for the venous blood in the tissue of all volunteers. The oxygenation is calculated by linear regression with a coefficient of determination R 2 of 0.9 which indicates that the fit by linear regression is a good approximation of the measurements and further indicates that a difference in the oxygenation between different subjects and different experiments is relatively small. The averaged venous oxygenation ratio of 0.87 obtained is lower than the arterial blood oxygenation ratio which is generally above 0.95, also during exercises. This demonstrates the principle of operation of the invention and supports the assumption that the attenuations shown in FIG. 6 are deduced from a venous blood signal. In consequence, this also supports the assumption that the variations of the volume of the blood caused by exercise are mainly due to relocation of the venous blood.
FIG. 7 illustrates the oxygenation changes during intense exercise measured with the system 40 . The horizontal axis t of FIG. 7 designates the time and the vertical axis SvO 2 designates the measured oxygenation of venous blood. The chosen example illustrates the oxygenation of venous blood dropping during an onset of an exercise. Two clearly visible negative peaks represent two drops at the onset of two sets of squats performed by a subject (a human volunteer) around the time 14:45 and the time 15:00 (marked with horizontal solid lines). FIG. 7 clearly shows that the system 40 is capable to measure the oxygenation of venous blood and that an oxygenation drop in the venous blood can clearly be related to movement of the subject, in this case to physical exercise in form of squats. The oxygenation of arterial blood would not feature such significant drops.
FIG. 8 shows an example continuous measurement with the system 40 of a subject, in this case a human volunteer performing normal life activities. An upper plot shows movements i.e. activities measured with accelerometer and a lower plot shows the corresponding venous oxygenation SvO 2 . Both plots have a horizontal axis t designating time, and the vertical axis of the upper plot MI designates a calculated motion intensity parameter calculated from relative changes of a 3-axes accelerometer measurements while the vertical axis SvO 2 of the lower plot designates the oxygenation of venous blood. Drops in the oxygenation of the venous blood in a first time periods 7:35-8:14 and in a second time period 12:00-12:40 be related to physical activities (a bicycle ride to the office in the first time period and walking for lunch and back in the second time period).
FIG. 9 shows the venous and arterial oxygenation of a person during a day. The horizontal axis t designates time and the vertical axis designates the arterial oxygenation SaO 2 as well as the venous oxygenation SvO 2 :SaO 2 is shown with a solid line and SvO 2 is shown with symbols. Filled circles show the results of the SvO 2 estimation with a coefficient of determination R 2 of above 0.9, while crosses feature R 2 between 0.8 and 0.9. A negative peak of the venous oxygenation around time 11:30 (marked in FIG. 9 with a double headed horizontal arrow) was induced on purpose by an occlusion of the blood vessels in the tissue (the occlusion reduced the maximal blood pressure to 20-40 mmHg and was induced between 11:00 h and 11:40 h). The induced occlusion demonstrates clearly that the expected drop in oxygenation of the venous blood can be measured by the system 40 . The oxygenation of the arterial blood does not indicate any significant events, while the drop in the oxygenation of the venous blood allows identifying the temporary induced occlusion.
FIG. 10 schematically shows a graph with the absorbance of different derivatives of hemoglobin in dependence of the wavelength of light. The vertical axis ∈ of the graph represents the absorbance i.e. a molar extinction coefficient [cm −1 /M] which measures how strongly the hemoglobin derivative absorbs light. The horizontal axis λ of the graph represents the wavelength [nm] of the light. The derivatives shown in FIG. 10 are methemoglobin (MetHb) and carboxyhemoglobin (COHb) represented by solid lines and oxyhemoglobin (oxyHb) and reduced hemoglobin (rHb) represented by broken lines. All derivatives vary strongly in the shown range of wavelength and can therefore be detected optically and discerned in measurements at wavelengths chosen appropriately.
While the invention has been described in present embodiments, it is distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practised within the scope of the claims.
LIST OF DESIGNATIONS
∈ molar extinction coefficient [cm −1 /M]
λ wavelength [nm]
oxyHb oxygenated hemoglobin
rHb reduced hemoglobin
t time
I intensity
Acc Y acceleration
r distance between light emitter and optical detector
S light emitter
D optical detector
Δ A ( 798 ) attenuation of infrared light
Δ A ( 660 ) attenuation of red light
MI calculated motion intensity parameter
SvO 2 oxygenation of venous blood
SaO 2 oxygenation of arterial blood
MetHb methemoglobin
COHb carboxyhemoglobin
oxyHb oxyhemoglobin
1 device
30 . 1 , 30 . 2 initial arterial attenuation signal
31 . 1 , 31 . 2 initial venous attenuation signal
32 . 1 , 32 . 2 measured optical signals
33 accelerometer signal
34 . 1 , 34 . 2 arterial portion signal
35 . 1 , 35 . 2 venous portion signal
40 system
41 frame
42 . 1 , 42 . 3 light detector compartment
42 . 2 light emitter compartment
43 glass plate
44 acceleration sensor
45 substrate
46 . 1 - 46 . 3 LEDs
47 . 1 , 47 . 2 monitoring photo diode
48 . 1 , 48 . 2 signal photo diode
49 photon path
50 . 1 , 50 . 2 reflective element
51 tissue
60 human skin
61 . 1 - 61 . 4 skin layer
62 photon path
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Embodiments of the present invention comprise systems and methods for noninvasion measurements of physiological properties of tissues. The system comprises a light emitter, an optical detector, a mechanical sensor and a processor. The light emitter is capable of emitting light of at least two different wavelengths and comprises at least one light source. The processor is capable of evaluating physiological properties of the tissues from measurements of the optical and the mechanical sensor. More precisely, the processor is capable of evaluating physiological properties of venous blood by using data measured by the mechanical sensor and the optical detector. For example, the oxygenation of venous blood can be measured. Furthermore, the systems can optionally comprise a light emitter which emits three wavelengths and/or the light emitter and the optical detector are arranged in reflection geometry and are located at a distance of at most 10 mm from each other.
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RELATED APPLICATIONS
[0001] None
BACKGROUND OF THE INVENTION
[0002] This invention relates to a liner for downhole components. Specifically, this invention is a metal tube having its original uniform shape sufficiently modified by the formation of non-uniform alterations to its shape so that it can be inserted into the bore of a downhole component and then expanded to conform to the interior surface of the downhole component. The shape modifications allow the tube to be expanded beyond its original diameter without rupturing the tube. The application of this invention is useful for any annular component in a production well or a drill string for drilling oil, gas, geothermal wells, or other subterranean excavations.
[0003] Provision of a liner in a drill pipe or other downhole component, including well casing, for the purpose of improving the corrosion resistance of the drill pipe or casing and for providing a passageway for electrical conductors and fluid flow is known in the art, as taught by the following references. U.S. Pat. No. 2,379,800, to Hare, incorporated herein by this reference, discloses the use of a protective shield for conductors and coils running along the length of the drill pipe. The shield serves to protect the conductors from abrasion that would be caused by the drilling fluid and other materials passing through the bore of the drill pipe.
[0004] U.S. Pat. No. 2,633,414, to Boivinet, incorporated herein by this reference, discloses a liner for an autoclave having folds that allows the liner to be installed into the autoclave. Once the liner is installed, it is expanded against the inside wall of the autoclave using hydraulic pressure.
[0005] U.S. Pat. No. 4,012,092, to Godbey, incorporated herein by this reference, discloses an electrical transmission system in a drill string using electrically conductive pipe insulated with a complementary sheath of elastic dielectric liner material. In order to ensure adequate electrical insulation at the ends of each tube, the sheath was slightly longer than its mating tube. The elastic nature of the sheath material enabled it to conform to the geometry of the drill pipe and its joint.
[0006] U.S. Pat. No. 2,982,360, to Morton et al., incorporated herein by this reference, discloses a liner for a well casing in a sour well, e.g. a well where hydrogen cracking and embrittlement are believed to be the cause of stress corrosion and failure of metal the well casing. The objective of the disclosure is to provide a liner to protect the casing and other downhole components from the effects of corrosion. A unique feature of this disclosure is that the liner is not bonded to the downhole component, in order to provide some void space between the liner and the component wall. However, it does teach that the metal liner can be expanded against the inside wall of the casing using mechanical or hydraulic pressure.
[0007] U.S. Pat. No. 4,095,865, to Denison et al., incorporated herein by this reference, discloses an improved drill pipe for sending an electrical signal along the drill string. The improvement comprises placing the conductor wire in a spiral conduit that is sprung against the inside bore wall of the pipe. The conduit serves to protect the conductor and provides an annular space within the bore for the passage of drilling tools.
[0008] U.S. Pat. No. 4,445,734, to Cunningham, incorporated herein by this reference, teaches an electrical conductor or wire segment imbedded within the wall of the liner, which secures the conductor to the pipe wall and protects the conductor from abrasion and contamination caused by the circulating drilling fluid. The liner of the reference is composed of an elastomeric, dielectric material that is bonded to the inner wall of the drill pipe.
[0009] U.S. Pat. No. 4,924,949, to Curlett, incorporated herein by this reference, discloses a system of conduits along the pipe wall. The conduits are useful for conveying electrical conductors and fluids to and from the surface during the drilling operation.
[0010] U.S. Pat. No. 5,311,661, to Zifferer, incorporated herein by this reference, teaches a method for forming corrugations in the wall of a copper tube. The corrugations are formed by drawing or pushing the tube through a system of dies to reduce the diameter of the end portions and form the corrugations in center portion. Although the disclosure does not anticipate the use of a corrugated liner in drill pipe or other downhole component, the method of forming the corrugations is readily adaptable for that purpose.
[0011] U.S. Pat. No. 5,517,843, to Winship, incorporated herein by this reference, discloses a method of making an upset end on metal pipe. The method of the reference teaches that as the end of the metal tube is forged, i.e. upset, the wall thickness of the end of the pipe increases and inside diameter of the pipe is reduced.
[0012] An object of the present invention, which is not disclosed or anticipated by the prior art, is to provide a liner that can be adapted for insertion into a downhole component and can accommodate the regular and varying inside diameters found in downhole components. An additional object of the invention is to provide a liner capable of withstanding the dynamic forces and corrosive and abrasive environment associated with drilling and production of oil, gas, geothermal resources, and subterranean excavation.
SUMMARY OF THE INVENTION
[0013] This invention discloses a liner for downhole annular components comprising an expandable metal tube suitable for conforming to an inside surface of the downhole component, wherein the downhole component may be uniform or non-uniform in cross section and/or material properties. The tube may be formed outside the downhole component and then inserted into the component, or it could be expanded and formed after being inserted into the component. In order to accommodate expansion of the tube and conformity with the interior of the downhole component, the tube is preformed with any of a variety of shape modifications comprising convolutions, corrugations, indentations, and dimples that generally increase the circumferential area of the tube and facilitate expansion of the tube to a desired shape. The metal tube may have generally a circular, square, rectangular, oval, or conic cross section, and the outer surface that interfaces with the inner surface of the downhole component may be polished, roughened, knurled, or coated with an insulating material. Depending on the desired application, the tube may be formed with sufficient force inside the component that it remains in compression against the inside surface wall of the component, or it may be expanded to a lesser diameter. For example, in some cases it may be desirable to expand the tube so that it merely contacts the inside wall of the component, or it may be desirable that the tube be expanded to a diameter that provides an annulus, or other space, between the tube and inside surface of the component. Where an annulus is provided, additional equipment such as pumps, valves, springs, filters, batteries, and electronic circuitry may be installed between the tube and the inside wall of the component. The tube also may be formed over one or more electrical or fiber optic conductors or conduits in order to provide protective passageways for these components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 is a perspective representation of a downhole component.
[0015] [0015]FIG. 2 is a perspective representation of a liner of the present invention having a convoluted non-uniform section along the length of the liner.
[0016] [0016]FIG. 3 is a perspective representation of an expanded liner of the present invention.
[0017] [0017]FIG. 4 is a sectioned perspective representation of a downhole tool having a liner.
[0018] [0018]FIG. 5 is an enlarged sectioned perspective representation of the pin end of a downhole tool.
[0019] [0019]FIG. 6 is a perspective representation of a liner of the present invention having a dimpled non-uniform section.
[0020] [0020]FIG. 7 is a perspective representation of a liner of the present invention having an ovoid non-uniform section.
[0021] [0021]FIG. 8 is a perspective representation of a liner of the present invention having a concave non-uniform section.
[0022] [0022]FIG. 9 is a perspective representation of a liner of the present invention having a corrugated non-uniform section.
[0023] [0023]FIG. 10 is a perspective representation of a liner of the present invention having a spirally fluted non-uniform section.
DETAILED DESCRIPTION OF THE INVENTION
[0024] Generally, downhole components are constrained within an annular geometry and capable of being connected to each other at designated locations along the drill string or along the well casing of an oil, gas, or geothermal well. Downhole components include drill pipe, drill collars, heavy weight drill pipe, casing, reamers, jars, shock absorbers, bit boxes, electronic subs, packers, bent subs, perforators, hydraulic motors, turbines, generators, pumps, down-hole assemblies, and batteries. The annular configuration of the components in a drill string is necessary in order to accommodate the flow of drilling fluid to the bit and for the insertion of well logging equipment and other tools into the borehole. In a production well, the annular components enable the flow of oil and gas to the surface and provide means for installing pumps, sensors, and other equipment into the producing well. One of the objectives of this invention, therefore, is to provide a liner that is capable of accommodating the various interior surfaces of the annular downhole components. The liner of this invention is useful for improving the hydraulics of fluid flow through the component, for increasing the component's resistance to corrosion, and for securing other sub-assemblies and equipment inside the downhole component.
[0025] Since downhole components share the annular geometry of a drill pipe, the detailed description of this invention will be directed to a liner within that downhole component. However, those skilled in the art will immediately recognize the application of this invention to the other downhole components that make up the drill string or production tubing in a well.
[0026] [0026]FIG. 1 is a perspective representation of a length of drill pipe ( 13 ) having a pin end tool joint ( 14 ) and a box end tool joint ( 15 ). The tool joints have thickened cross sections in order to accommodate mechanical and hydraulic tools used to connect and disconnect the drill string. Drill pipe usually consists of a metal tube to which the pin end tool joint and the box end tool joint are welded. Similar tool joints are found on the other downhole components that make up a drill string. The tool joints may also have a smaller inside diameter ( 18 ), in order to achieve the thicker cross section, than the metal tube and, therefore, it is necessary to forge, or “upset”, the ends of the tube in order to increase the tube's wall thickness prior to the attachment of the tool joints. The upset end portion ( 19 ) of the tube provides a transition region between the tube and the tool joint where there is a change in the inside diameter of the drill pipe. High torque threads ( 16 ) on the pin end and ( 17 ) on the box end provide for mechanical attachment of the downhole tool in the drill string. Another objective of this invention, therefore, is to provide a liner that will accommodate the varying diameters inside a drill pipe or other downhole component and not interfere with the make up of the drill string.
[0027] [0027]FIG. 2 is an illustration of a liner ( 20 ) of the present invention. It comprises a metal tube having uniform end portions ( 21 ) and a non-uniform section consisting of intermediate corrugations ( 22 ). In this figure, the corrugations extend longitudinally along the length of the tube, parallel to the axis of the tube. At the ends of each corrugation are transition regions that may generally correspond to the transitional regions within the upset drill pipe. The wall thickness of this liner may range from between about one half the wall thickness to greater than the thickness of the tube wall. Suitable metal materials for the liner may be selected from the group consisting of steel, stainless steel, aluminum, copper, titanium, nickel, molybdenum, and chromium, or compounds or alloys thereof. The liner is formed by providing a selected length of tubing having an outside diameter less than the desired finished diameter of the liner and drawing the tube through one or more dies in order to form the end portions and corrugations. The outside diameter of the liner may also be reduced during this process. Alternatively, the convolutions are formable by metal stamping, hydroforming, or progressive roll forming. In cases where the entry diameter of the tool joint is smaller than the inside diameter of the tube, the outside diameter of the tube may need to be decreased during the process of forming the end portions and corrugations, so that it can be inserted into a downhole component such as the drill pipe of FIG. 1,. Once the tube is inside the component, the tube is plugged and hydraulically or mechanically expanded to its desired diameter. The shape modification in the tube allow the tube to expand to at least its original outside diameter and beyond, if so desired, without excessively straining the material of the tube. In this fashion the tube can accommodate the changing inside diameter of the downhole component. Another method of expanding the tube is depicted in U.S. Pat. No. 2,263,714, incorporated herein by this reference, which discloses a method of drawing a mandrel through a lining tube in order to expand it against the wall of a pipe. Although the reference does not anticipate a varying inside diameter, the mandrel could be adapted, according to the present invention, to vary with the varying size of the tube within the downhole component.
[0028] [0028]FIG. 3 is a representation of the expanded liner ( 30 ) of the present invention. For clarity the downhole component into which the liner has been expanded is not shown. The non-uniform section of the liner has been expanded to accommodate a downhole component having a changing diameter in the transition region ( 31 ) and a smaller inside diameter at end portions ( 32 ). For example, in order to provide a liner for an upset, 5⅞″ double-shouldered drill pipe obtainable from Grant Prideco, Houston, Tex., having a tool joint inside diameter of approximately 4¼″ and a tube inside diameter of approximately 5″, a 316 stainless steel tube of approximately 33′ in length and having a wall thickness of about 0.080″ was obtained. The stainless steel ltube was drawn through a series of tungsten-carbide forming dies at Packless Metal Hose, Waco, Tex., in order to draw down the outside diameter of the tube to about 4.120″. At the same time, the carbide dies formed the end portions and the corregations of the non-uniform section similar to those shown in FIG. 1. A tube similar to that shown at FIG. 1 was then inserted into the drill pipe, and the assembly was placed inside a suitable press constructed by the applicants. The end of the tube portions were sealed using hydraulic rams that were also capable of forcing pressurized water into the tube. Once the tube was completely filled with water, the pressure of the water was increased in order to expand the tube to match the inside diameter of the downhole tool, i.e. drill pipe. At around 150 psi the corrugations began to move or expand, as was evidenced by noises coming from inside the pipe as the corrugations buckled outward. The pressure was increased to between 3500 and 5000 psi whereupon the expansion noises nearly ceased. The applicants concluded that at about this time the liner was fully expanded against the inside wall of the pipe. Pressure inside the tube was then increased to above 10,000 psi whereby it is thought that the pipe expanded within its elastic limit, while the liner expanded beyond its plastic limit, thereby placing the liner in compression against the inside wall of the pipe after removal of pressure. When the pipe was removed from the press, visual inspection revealed that the liner had taken on the general shape as depicted in FIG. 3, and that the liner had been fully expanded against the inside diameter of the drill pipe. The applicant attempted to vibrate and remove the liner but found that it was fixed tightly inside the pipe.
[0029] [0029]FIG. 4 is an axial cross-section representation of a drill pipe ( 40 ) similar to that depicted in FIG. 1 with a liner ( 43 ) similar to that shown in FIG. 3. The thickened wall ( 41 ) of the pin end and the thickened wall ( 42 ) of the box end tool joints are depicted. The upset transition regions ( 44 ) at the pin end and ( 45 ) at the box end are also identified. For clarity, the liner ( 43 ) is shown not fully expanded against the inside wall of the drill pipe ( 40 ). However, as the liner is fully expanded against the inside wall of the downhole tool, the transition regions serve to lock the liner in place so that the liner is not only held in position by being in compression against the wall of the pipe, but is also locked in position by the changing inside diameter. A liner thus installed into a downhole tool has many advantages. Among these are the improvements of the hydraulic properties of the bore of the tool as well as corrosion and wear resistance.
[0030] [0030]FIG. 5 is an enlarged representation of the pin end of FIG. 4. The thickened wall ( 50 ) of the tool joint is identified as well as the transition region ( 51 ) of the downhole tool. In the liner ( 52 ), the transition region ( 53 ) is depicted. Once again for clarity, the liner is depicted not fully expanded against the inside wall of the pipe. In actuality, at this stage of expansion, where the liner is not fully expanded, it is expected that the remains of the corrugations would still be visible. It is not expected that the corrugations would be fully ironed out until the tube is fully pressed against the tool wall. It will be noted that where differing materials are used, for example where the tool consists of 4100 series steel and the liner is a stainless steel, the intimate contact of the differing materials may induce a corrosive condition. In order to prevent galvanic corrosion, the liner or the tool, or both, may be coated with an electrically insulating material that would interrupt any galvanic current that might form when the liner and tool surface come in contact with each other in the presence of an electrolyte.
[0031] [0031]FIG. 6 illustrates a liner ( 60 ) having end portions ( 61 ) and a non-uniform section of dimpled indentations ( 62 ) along the length of the tube. The dimples could be positive or negative with respect to the surface of the liner. As depicted the dimples are generally round in shape, but they could be ovoid or elongated as shown in FIG. 7, and the properties of FIG. 6 are applicable to the properties of FIG. 7, and vice versa, where the non-uniform section of the tube ( 70 ) has ovoid indentations ( 71 ). Although, the dimple pattern as shown is regular in both figures along the longitudinal axis of the tube, alternative patterns are possible and could be beneficial. For example, the pattern could be spiral or the pattern could consist of a combination of shapes alternating within the border region ( 72 ).
[0032] [0032]FIG. 8 is a representation of another non-uniform section of the present invention provided in a tube. The deformation consists of a single corrugation ( 81 ) along the full lengthwise axis of the tube ( 80 ). Multiple corrugations are possible, but a single corrugation may be adequate. This design could also be used in connection with the regular end portions of FIG. 2. This modified “D” configuration is appealing for its simplicity in design, and yet it is capable of accommodating a downhole tool having a regular inside diameter. Tests by the applicants have shown that both thick and thin-walled tubing, having a thickness between about 0.010″ and about 0.120″ benefit from the non-uniform section of the present invention during expansion. Without the non-uniform section, finite-element analysis has shown that the liner will likely rupture before it is sufficiently expanded against the tool wall. The configuration depicted in FIG. 8 may be useful in situations where it is desired to place a conduit or conductor cable along the inside of the downhole tool. The corrugation would provide a pathway for the conduit and would form itself around the conduit during expansion. In this embodiment not only would the liner benefit the performance of the pipe, but it would also serve to fix the conduit or cable in place and protect it from the harsh downhole environment.
[0033] [0033]FIG. 9 is a representation of a non-uniform section ( 91 ) provided in a tube ( 90 ). The non-uniform section consists of longitudinal corrugations that may or may not extend the full length of the tube. As depicted, the corrugations are at regular intervals around the circumference of the tube, however, the applicants believe that an irregular pattern may be desirable depending on the configuration of the inside wall against which the tube will be expanded. The desired depth of the corrugations as measured perpendicularly from the crest of the outer-most surface to the inside diameter as represented by the inner most surface of the trough may be determined by the total expansion required of the liner. For example, if the liner were to be installed into a downhole tool having a uniform inside diameter, the corrugations would not have to be as deep as the corrugations would need to be if the liner were to be installed into a tool having a varying inside diameter. For example, for a tool having a uniform inside diameter, the depth of the corrugations could be approximately equivalent to one half of the wall thickness of the tube prior to formation of the corrugations and be adequate to achieve sufficient expansion inside the tool, depending on the number of corrugations and their proximity to each other. On the other hand, where the inside wall of the tool has a varying diameter, the corrugations may have to exceed the greatest variation between inside diameter irregularities. These critical dimensions are best obtained for a given tool design by experimenting with the thickness and shape of the non-uniformities. The determination of optimum dimensions is included within the teachings of the liner of the present invention.
[0034] [0034]FIG. 10 is a representation of the liner of FIG. 9 modified so that the liner ( 100 ) exhibits a non-uniform section along its length consisting of an inner wall ( 101 ) and an outer wall ( 102 ) made up of indentations that are formed into spiral flutes. This configuration would be useful in downhole tools having uniform inside wall surfaces. The flutes could be proportioned so that conduits and conductors could be disposed within the troughs and run along the full length of the downhole tool. Such conduits and conductors would then be protected from the harsh fluids and tools that are circulated through the tool's bore. In cases where it would be desirable to control the flow of fluid through the bore of the downhole tool, it may be desirable to expand the liner in such a manner so that the form of the indentations remain in the inside wall of the liner after it has been fully expanded. The modified flow produced by the presence of indentations in the inner wall of the downhole tool might be beneficial in reducing turbulence that tends to impede efficient flow of fluid through the tool.
[0035] Other and additional advantages of the present invention will become apparent to those skilled in the art and such advantages are incorporated in this disclosure. The figures presented in this disclosure are by way of illustration and are not intended to limit the scope of this disclosure.
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A liner for an annular downhole component is comprised of an expandable metal tube having indentations along its surface. The indentations are formed in the wall of the tube either by drawing the tube through a die, by hydroforming, by stamping, or roll forming and may extend axially, radially, or spirally along its wall. The indentations accommodate radial and axial expansion of the tube within the downhole component. The tube is inserted into the annular component and deformed to match an inside surface of the component. The tube may be expanded using a hydroforming process or by drawing a mandrel through the tube. The tube may be expanded in such a manner so as to place it in compression against the inside wall of the component. The tube is useful for improving component hydraulics, shielding components from contamination, inhibiting corrosion, and preventing wear to the downhole component during use. It may also be useful for positioning conduit and insulated conductors within the component. An insulating material may be disposed between the tube and the component in order to prevent galvanic corrosion of the downhole component.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present patent application claims the priority benefit of provisional patent application Ser. No. 60/967,209, filed on Aug. 31, 2007, which provisional patent application is presently pending.
TECHNICAL FIELD
[0002] The present invention relates to motor vehicle suspension systems, wherein the motor vehicle body is sprung in relation to each of its wheels via a respective spring-damper combination. More particularly, the present invention relates to a method for providing a progressive optimal damper response to jounce events, including those involving maximum wheel displacements.
BACKGROUND OF THE INVENTION
[0003] Motor vehicle suspension systems are configured so that the wheels are able to follow elevational changes in the road surface as the vehicle travels therealong. When a rise in the road surface is encountered, the suspension responds in “jounce” in which the wheel is able to move upwardly relative to the frame of the vehicle. On the other hand, when a dip in the road surface is encountered, the suspension responds in “rebound” in which the wheel is able to move downwardly relative to the frame of the vehicle. In either jounce or rebound, a spring (i.e., coil, leaf, torsion, etc.) is incorporated at the wheel in order to provide a resilient response to the respective vertical movements with regard to the vehicle frame. However, in order to prevent wheel bouncing and excessive vehicle body motion, a damper (i.e., shock absorber, strut, etc.) is placed at the wheel to dampen wheel bounce. Additionally, when the limit of jounce is encountered, it is customary to provide a maximum jounce impact absorber in the form of a bumper cushion.
[0004] Referring now to FIGS. 1 through 1B , components of a conventional suspension system 10 are depicted which allow for jounce and rebound at a wheel of the subject motor vehicle 12 .
[0005] Firstly with regard to FIG. 1 , a control arm 14 is pivotally mounted with respect to the frame 16 , wherein, in the depicted example, a torsion spring 18 is utilized to provide resilient response for the jounce and rebound of the control arm relative to the frame. To provide control over the rate of jounce and rebound, a damper in the form of a shock absorber 20 is connected pivotally at one end to the frame 16 and connected pivotally at the other end to the control arm 14 . Alternatively, a damper in the form of a strut may be used in the suspension system, as for example disclosed in U.S. Pat. No. 5,467,971. To provide cushioning in the event a maximum jounce occurs, a jounce bumper cushion 22 is mounted to the frame 16 which is resiliently compressed by movement of the control arm as jounce approaches its maximum.
[0006] Referring next to FIG. 1A , the internal components and operational aspects of a conventional shock absorber 20 ′ (a remote reservoir high pressure gas type shock absorber being shown merely by way of example) can be understood. A valved piston 30 is reciprocably movable within a shock cylinder 32 . A shock rod 34 is attached to the valved piston 30 and is guided by a shock rod guide 36 at one end of the shock cylinder 32 . Below the valved piston 30 and above the shock rod guide 36 is a mutually interacting rebound limiter 38 . The instantaneous position of the valved piston 30 within the shock cylinder 32 defines a first interior portion 32 F and a second interior portion 32 S of the interior of the shock cylinder. In the example depicted at FIG. 1A , the pressurization in the first and second interior portions 32 F, 32 S is provided by an hydraulic fluid O which is pressurized by pressurized gas, preferably nitrogen, G acting on a divider piston 40 of an hydraulic fluid reservoir cylinder 42 , wherein a tube 44 , including a base valve 44V, connects the hydraulic fluid between the hydraulic fluid reservoir cylinder and the first interior portion. In operation, as the control arm undergoes jounce, the hydraulic fluid is displaced from the first interior portion into the hydraulic fluid reservoir cylinder, causing the pressure of the nitrogen gas to increase as its volume decreases and thereby causing an increased hydraulic pressure on the valved piston 30 in a direction toward the shock rod guide. Hydraulic fluid is able to directionally meter through valving 46 of the valved piston 30 in a manner which provides damping.
[0007] Referring next to FIG. 1B , the internal structure of a conventional jounce bumper cushion 22 can be understood. An optional skin 50 of a compliant material (i.e., having energy absorbing or damping properties) may, or may not, overlay an interior of resilient elastomeric material 52 , which may be for example a rubber, rubber-like material, or micro-cellular urethane. In operation as the control arm approaches maximum jounce, the jounce bumper cushion 22 compresses, delivering a reaction force on the control arm which increases with increasing compression so as to minimize the severity of impact of the control arm with respect to the frame at the limit of jounce. Immediately following the jounce, the rebound involves the energy absorbed by the compression of the conventional bumper cushion being delivered resiliently back to the suspension.
[0008] In the art of motor vehicle suspension systems, it is known that a conventional jounce bumper cushion and related dampers can show wear. It is also known that when the energy absorbed from a particular bump or dip exceeds the capacity of a conventional jounce bumper cushion, a hard mechanical stop is engaged. This abrupt transfer of jounce force and energy to the frame manifests itself in the passenger compartment as a sharp jolt, which can create load management issues in addition to the discomfort of a rough ride. Further, in order for the frame to accept such impact loads, the structure of the frame must be engineered for an appropriate strength, which is undesirable from the standpoint of the added vehicle weight such structures must inherently entail.
[0009] Vehicle suspension engineering has traditionally focused on ride and handling as this pertains to body and wheel relative motion with respect to the body below about 1.5 m/s (meters per second). However, the suspension travel requirements in a vehicle are mainly driven by severe events which generate maximum displacements of the wheel relative to the body. These severe events, such as when the vehicle encounters a deep and steep-walled pothole, can generate wheel velocities (relative to the body) of up to 9 m/s.
[0010] An approach pursued by Bavarian Motor Works (BMW) of Munich, Germany, is described in European Patent Application EP 1,569,810 B1, published on Sep. 7, 2005; which application is parent to U.S. Patent Application publication 2006/0243548 A1, published on Nov. 2, 2006.
[0011] The object of the BMW disclosure of EP 1,569,810 B1 is to provide a vibration damping method on a motor vehicle wheel suspension by means of a hydraulic vibration damper which prevents great loads on the vehicle body and chassis caused by very large vertical velocities of the wheel, e.g., when traveling over potholes. According to the BMW disclosure, in a hydraulic vibration damper for a motor vehicle, a method of vibration damping on a wheel suspension is used by BMW, characterized in that the damping force of the vibration damper increases as a function of piston speed, especially in the piston speed range of essentially 0 to 2 m/s, at first increasing slowly, essentially linearly, and then, especially above a piston speed of essentially 2 m/s, increasing according to a highly progressive function. Further according to the BMW disclosure, through a suitable choice, design and construction of vibration damper valves or by otherwise influencing the hydraulic resistances in the vibration damper, it is possible to implement a characteristic which is generated by damping forces known from the state of the art in the piston speed range up to the end of the range that is relevant for comfort, and beyond this piston speed range, an extreme progression in the damper characteristic is induced to decelerate the accelerated masses to a greater extent.
[0012] While the BMW disclosure seeks to provide a solution to the long-standing problem of damping excessively large wheel-to-body velocities while attempting to maintain acceptable ride and handling for low velocities, the disclosure requires an ad hoc reliance upon a presupposed and essential damper curve which is devoid of any underlying physics which supports any of the curve aspects. Thus, what yet remains needed in the art is an analytical methodology to predict damping curves which truly achieve the goal of damping excessively large wheel-to-body velocities while attempting to maintain acceptable ride and handling for low velocities.
[0013] Of additional note is Japan Society of Automotive Engineers, JSAE technical paper 9306714 by Miyazaki, Kiyoaki, Yasai, Hirofumi, “A study of ride improvement of the bus”, JSAE Autumn Convention Nagoya, Japan Oct. 19-21, 1993, wherein the authors confirmed that a progressive damping characteristic is effective for reducing the pitching and impact vibration.
[0014] Of further note is Society of Automotive Engineers, SAE technical paper 2006-01-1984 by Benoit Lacroix, Patrice Seers and Zhaoheng Liu, “A Passive Nonlinear Damping Design for a Road Race Car Application”, wherein a nonlinear passive damping design is proposed to optimize the handling performance of an SAE Formula car in terms of roll and pitch responses.
[0015] Progressive damping is thought of as an enabler to reduce harsh impact, ride input feel when encountering severe events through the method of maintaining a predefined load in jounce and reducing engagement into the jounce suspension stop. It is also needed to develop enablers to reduce total jounce travel so that a given vehicle could be trimmed lower to enable competitive styling cues. Trimming a vehicle lower usually increases the level of harshness for an event such as a deep pothole and other severe events.
[0016] What remains needed in the art, therefore, is an analytical methodology for the specification of progressive optimal compression damping that enables the suspension to negotiate severe events with reduced harshness, yet provides very acceptable ride quality and handling during routine events, limits peak loads on the fame structure, reduces wheel travel, and enables lower trim height.
SUMMARY OF THE INVENTION
[0017] The present invention is an analytical methodology for the specification of progressive optimal compression damping that enables a motor vehicle suspension system to negotiate severe events, such as potholes, with reduced harshness, yet provides very acceptable ride quality and handling during routine events, such as common road surfaces, limits peak loads on the frame structure, reduces wheel travel, and enables lower trim height.
[0018] In a broadest aspect of the present invention, a method is provided for a progressive optimal unconstrained damping response of the wheel assembly with respect to the body. In a preferred aspect of the present invention, a method is provided for a progressive optimal constrained damping response of the wheel assembly with respect to the body.
[0019] The method to provide a progressive optimal unconstrained damping response of the wheel assembly with respect to the body is generated from equations of motion of the wheel center of the wheel assembly with no initial external forces, no initial displacement, and the total force acting on the wheel center is essentially constant (hereafter referred to simply as “constant total force) during the wheel center's deceleration from an initial velocity U 0 to a velocity of zero. The constant total force is related to a determined travel length of the wheel center such that when the wheel center is at the determined travel length, its velocity is zero, the damper force is zero and the suspension spring is compressed the determined travel length by which the suspension spring force is equal to the constant total force and when the wheel center is at zero displacement its velocity is U 0 , the suspension spring is uncompressed with respect to equilibrium by which the suspension spring force is zero, and the damper force is equal to the constant total force. With the above conditions, the amount of energy dissipated by the damper is maximized and the total load on the body is minimized, whereby a progressive optimal unconstrained damper force is obtained which is valid for all displacements of the wheel center from zero to the predetermined travel length and velocities from U 0 to zero.
[0020] The suspension spring may include coil spring, jounce bumper, mounts, and other suspension compliances. Suspension spring force as a function of wheel center travel can be determined in the lab through the standard technique, where the tire patches are actuated vertically in jounce and rebound while the force is measured through the force tables and wheel transducer systems.
[0021] In practice, a predetermined damper force acting on the wheel center below a wheel center velocity u 1 , approximately 2.0 m/s, is based on ride and handling considerations for a given vehicle or vehicle model according to the prior art methodology, and should not be altered therefrom. A method to provide a progressive optimal constrained damping response of the wheel assembly with respect to the body, in which the predetermined damper force acting on the wheel center below or equal to a wheel center velocity of u 1 , approximately 2.0 m/s, is not altered, is generated as described below:
[0022] 1. A progressive optimal constrained damper force is obtained from equations of motion of the wheel center with no initial external forces, an initial displacement x 0 when the initial velocity is U 0 , and the total force acting on the wheel center is constant during the wheel center's deceleration from a velocity U 0 to an empirically determined velocity u 2 . The constant total force acting on the wheel center is related to equations of motion of the wheel center and predetermined vehicle parameters.
[0023] 2. A smooth, continuous damping force transition function is obtained, preferably approximating a step function, producing a damping force from the wheel center velocity u 1 to an empirically determined wheel center velocity u 2 greater than u 1 , but neighboring, u 1 .
[0024] 3. The predetermined damper force acting on the wheel assembly is used below or equal to a wheel assembly velocity u 1 .
[0025] The constant total force is related to a determined travel length of the wheel center such that when the wheel center is at the determined travel length, its velocity is zero, the damper force is zero and the suspension spring is compressed the determined travel length by which the suspension spring force is equal to the constant total force and when the wheel center is at displacement x 0 its velocity is U 0 , the suspension spring is compressed by x 0 .
[0026] With the above conditions, the amount of energy dissipated by the damper is maximized and the total load on the body is minimized whereby a progressive optimal constrained damping function is obtained valid for all displacements of the wheel center from zero to the determined travel length and velocities from U 0 to zero.
[0027] Accordingly, it is an object of the present invention to provide an analytical methodology for the specification of progressive optimal compression damping that enables a motor vehicle suspension system to negotiate severe events, such as potholes, with reduced harshness, yet provides very acceptable ride quality and handling during routine events, such as common road surfaces, limits peak loads on the frame structure, reduces wheel travel, and enables lower trim height.
[0028] This and additional objects, features and advantages of the present invention will become clearer from the following specification of a preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 is a perspective view of a conventional motor vehicle suspension system, including a control arm, a frame, a spring, a conventional shock absorber and a conventional bumper cushion.
[0030] FIG. 1A is a sectional view of a conventional shock absorber.
[0031] FIG. 1B is a sectional view of a conventional bumper cushion.
[0032] FIG. 2 is a diagrammatic view of a motor vehicle suspension system depicting a sprung mass (i.e., vehicle body), unsprung mass (i.e., wheel assembly), a spring, a damper, and a jounce bumper of a motor vehicle.
[0033] FIG. 3 is a graph of a plot of suspension spring normal force versus wheel center displacement for a representative motor vehicle.
[0034] FIG. 4 is a graph of progressive optimal unconstrained damping force at the wheel center versus wheel center vertical velocity for the representative motor vehicle of FIG. 3 according to the present invention.
[0035] FIG. 5 is a graph of damper force versus damper velocity for the representative motor vehicle of FIG. 3 , showing a first plot of damping for a conventional passive damper, and a second plot of progressive optimal unconstrained damping according to the present invention.
[0036] FIG. 6 is a flow chart of an algorithm for a progressive optimal unconstrained damper force according to a broadest aspect of the present invention.
[0037] FIG. 7A is a flow chart of an algorithm to determine a constant total force for a progressive optimal constrained damping function according to a most preferred aspect of the present invention.
[0038] FIG. 7B is an example of a graph showing exemplar plots for carrying out the algorithm of FIG. 7A .
[0039] FIG. 7C is a flow chart of an algorithm for the progressive optimal constrained damping function according to a most preferred aspect of the present invention.
[0040] FIG. 8 is a graph of damper force versus damper velocity, showing a first plot of damping for a conventional passive damper, and a second plot of progressive optimal constrained damping according to the present invention, given the plot of FIG. 3 .
[0041] FIG. 9 is a graph of time versus total suspension load, showing a first plot of a simulated suspension load having conventional passive damping; a second plot of a simulated suspension load having progressive optimal constrained damping according to the present invention; and a third plot of a simulated suspension load having progressive optimal unconstrained damping according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0042] Referring now to the Drawing, FIGS. 2 through 9 depict various aspects of the methodology according to the present invention to provide optimized damping in a motor vehicle suspension system.
[0043] Generally speaking, the performance of motor vehicles under severe road events is tested using a pavement which includes a series of potholes. For example, a minor pothole would be a shallow pit, and more pronounced pothole would be a deeper pit capable of causing passengers to feel a bounce; and a “sever event” pothole would be a box-shaped drop-off pit with a hard, square edge at the back.
[0044] The following analysis is focused on motor vehicle suspension response to traversal of a “severe event” pothole. During a “severe event” pothole traversal, the wheel first falls into the pothole, followed by the falling body corner, and then, in an already jounced position (compared to nominal trim position), hits a steep bump approximating a step. Tire forces then accelerate the wheel and the suspension goes into a deep jounce. Wheel vertical velocity reaches its peak, about 5 m/s, (MKS units being used herein) sometime through the jounce travel and then decreases to zero at the maximum jounce travel (where the maximum shock tower vertical load is achieved). The deceleration portion of the jounce event (from the maximum wheel speed to zero) is modeled with the help of a one degree of freedom (1DOF) nonlinear mechanical system, as described below.
[0045] FIG. 2 is a diagrammatic view 200 of a vehicle suspension system, typically used in the art, depicting the relationship of predetermined sprung mass 202 (i.e., the vehicle body), predetermined unsprung mass m (i.e., the wheel assembly), nonlinear predetermined spring 204 , nonlinear damper 206 (i.e., shock absorber, etc.), and jounce bumper 208 . Herein, the predetermined sprung mass 202 is referred to simply as the “body” wherein the body serves as the reference for measuring velocity of the unsprung mass and the predetermined unsprung mass m is referred to simply as the “wheel assembly” 216 .
[0046] In FIG. 2 , the velocity, {dot over (x)}, or y (i.e., y={dot over (x)}), in the vertical direction x of the wheel center C w of the wheel assembly 216 with respect to the body 202 is related to the velocity v, in the vertical direction x with respect to the body, of the bottom 214 of damper 206 where it connects to the wheel assembly at point 212 , by a predetermined ratio r such that y=v/r. Herein the velocity v is referred to as the damper velocity and the wheel center C w is the centerline of the wheel assembly 216 .
[0047] The wheel assembly 216 is attached to the body 202 by the nonlinear predetermined spring 204 and by the nonlinear damper 206 (the jounce bumper 208 is usually independently interfaced between the wheel assembly and the body). The displacement of the wheel center with respect to the equilibrium position (nominal trim) 210 is in the vertical direction x and L is the travel length of the wheel center with respect to the equilibrium position in the vertical direction x, which could include a portion of the jounce bumper 208 , and also corresponds to the compression length of the predetermined spring 204 . The travel length L is less than or equal to a predetermined maximum travel length L MAX in the vertical direction x, as depicted merely by way of example in FIG. 2 . The wheel assembly 216 and its mass m, predetermined travel length L, the predetermined maximum travel length L MAX , the spring 204 , the body 202 , and predetermined ratio r are empirically or analytically determined for a particular vehicle or vehicle model by the vehicle manufacturer.
[0048] The equation of motion with no external forces acting on the wheel center C w has the following form with the given initial conditions:
[0000] m{umlaut over (x)}+F ( x )+Φ( {dot over (x)} )=0, x (0)= x 0 , {dot over (x)} (0)= U 0 (1)
[0000] wherein x is the displacement of the wheel center with respect to the equilibrium position 210 , {dot over (x)} or y (i.e., y={dot over (x)}) is the wheel center velocity with respect to the body 202 , {umlaut over (x)} is the wheel center acceleration with respect to the body, Φ({dot over (x)}) is the damper force of the damper 206 as a function of wheel center velocity {dot over (x)}, F(x) is the suspension spring force of the spring 204 acting on the wheel center C w at the displacement x corresponding to a compression of the spring by a displacement x, x(0) is the position of the wheel center at time t=0 with respect to the equilibrium position 210 , x 0 is the initial position of the wheel center at time t=0 with respect to the equilibrium position 210 , {dot over (x)}(0) is the velocity of the wheel center with respect to the body 202 at time t=0, the travel length L is predetermined, and U 0 is a predetermined initial velocity of the wheel center with respect to the body at time t=0. In reality, suspension ride spring and damper are not collocated and wheel center vertical travel is not equal to the damper (shock) displacement. Given the predetermined ratio of damper (shock) travel per unit of vertical wheel center travel, r, y=v/r, wherein v is the damper (shock) velocity, and a predetermined initial damper velocity V 0 , U 0 can be calculated from U 0 =V 0 /r.
[0049] For the system 200 described by equation (1), assuming the velocity {dot over (x)}=y=0 when x=L≦L MAX , the suspension spring force F(x) of the spring 204 acting on the wheel center C w is equal to F(L). If the total force, F(x)+Φ({dot over (x)}) acting on the wheel center C w during its deceleration from U 0 to 0 is constant and equal to F(L), then the amount of energy dissipated by the damper 206 is maximized, and the total load on the body 202 is minimized. This leads to the following condition:
[0000] F ( x )+Φ( y )= F ( L )=constant (2)
[0000] valid for 0≦x≦L≦L MAX , and 0≦y≦U 0 where Φ(y)=Φ({dot over (x)}) represents a smooth, continuous, and monotonically increasing progressive optimal unconstrained damper force of damper 206 as a function of wheel center velocity y.
[0050] For initial conditions of the wheel center C w being x(0)=x 0 =0 and {dot over (x)}(0)=U 0 , when the total force acting on the wheel center during its deceleration from a velocity of U 0 to 0 is constant and equal to F(L) and the progressive optimal unconstrained damper force Φ(y=0)=0, then the progressive optimal unconstrained damper force Φ(y) as a function of wheel center velocity y of equation (2) can be expressed as:
[0000]
Φ
(
y
)
=
F
(
L
)
-
F
(
(
1
-
y
2
U
0
2
)
L
)
whereby
0
≤
y
≤
U
0
and
,
(
3
)
m
*
U
0
2
2
=
L
*
F
(
L
)
(
4
)
[0000] which represents a kinetic energy constraint and wherein “*” represents a multiplication symbol.
[0051] The function
[0000]
F
(
(
1
-
y
2
U
0
2
)
L
)
[0000] is the suspension spring force of the spring 204 acting on the wheel center C w when the wheel center velocity is y where 0≦y≦U 0 .
[0052] Since y=v/r and U 0 =V 0 /r, using equation (3), a progressive optimal unconstrained damper force Ψ 1 (v) as a function of damper velocity v can be expressed as:
[0000]
Ψ
1
(
v
)
=
Φ
(
y
=
v
/
r
)
r
or
equivalently
as
:
(
5
)
Ψ
1
(
v
)
=
F
(
L
)
-
F
(
(
1
-
v
2
V
0
2
)
L
)
r
.
(
6
)
[0053] The function
[0000]
F
(
(
1
-
v
2
V
0
2
)
L
)
[0000] is the suspension spring force of the spring 204 acting on the wheel center C w when the damper velocity is v where 0≦v≦V 0 .
[0054] An example of implementation of the foregoing will now be detailed with respect to FIGS. 3 and 4 , wherein FIG. 3 is a graph 300 of a plot 302 of suspension spring normal force versus wheel center displacement for a representative motor vehicle; and FIG. 4 is a graph 400 of progressive optimal unconstrained damper force Φ(y) versus wheel center vertical velocity, plot 402 , for the representative motor vehicle of FIG. 3 according to the present invention.
[0055] Given the wheel assembly mass m and the velocity U 0 , the travel length L can be determined from the kinetic energy constraint of equation (4) as follows: A graph of the product of spring displacement x times suspension spring force F(x) (i.e., xF(x)) versus spring displacement x for the predetermined spring 204 is plotted. The point on the x axis of the plot whereat the xF(x) axis equals
[0000]
m
*
U
0
2
2
[0000] corresponds to the predetermined travel length L where L≦L MAX wherein U 0 is chosen such that L≦L MAX . Then F(L) can be ascertained from a graph (as per FIG. 3 ) of a plot of suspension spring force F(x) versus spring displacement x for the predetermined spring 204 . The quantity
[0000]
[
(
1
-
y
2
U
0
2
)
L
]
[0000] in equation (3) can be evaluated for a velocity y, where 0≦y≦U 0 , by which the suspension spring force
[0000]
F
(
(
1
-
y
2
U
0
2
)
L
)
[0000] of the predetermined spring 204 can be obtained from the graph of suspension spring force F(x) versus spring displacement x of the predetermined spring (i.e., FIG. 3 ). The progressive optimal unconstrained damper force Φ(y) as a function of wheel center velocity y of the damper 206 can now be determined from equation (3). A plot of the progressive optimal unconstrained damper force Φ(y) versus y can subsequently be obtained and plotted using equation (3) for various values of y.
[0056] Alternatively to the immediately above paragraph, given a travel length L, F(L) can be ascertained from a graph (as per FIG. 3 ) of a plot of suspension spring force F(x) versus spring displacement x for the predetermined spring 204 . Velocity U 0 can be determined from equation (4). The quantity
[0000]
[
(
1
-
y
2
U
0
2
)
L
]
[0000] in equation (3) can be evaluated for a velocity y, where 0≦y≦U 0 , by which the suspension spring force
[0000]
F
(
(
1
-
y
2
U
0
2
)
L
)
[0000] of the predetermined spring 204 can be obtained from the graph of suspension spring force F(x) versus spring displacement x of the predetermined spring (i.e., FIG. 3 ). The progressive optimal unconstrained damper force Φ(y) as a function of wheel center velocity y of the damper 206 can now be determined from equation (3). A plot of the progressive optimal unconstrained damper force Φ(y) versus y can subsequently be obtained and plotted using equation (3) for various values of y.
[0057] For example, in FIG. 4 m=55.5 kg, L MAX =0.095 m, L=0.081 m, V 0 =2.7 m/s, and r=0.65 from which U 0 =2.7/0.65 m/s=4.1538 m/s. From point 304 of FIG. 3 , F(L) is, approximately, 5.9 kN for L=0.081 m corresponding to point 404 of FIG. 4 , where U 0 =4.1538 m/s which agrees with equation (3) where Φ(U 0 )=F(L). For a wheel center velocity of, for example, y=2 m/s, the quantity
[0000]
[
(
1
-
y
2
U
0
2
)
L
]
=
0.062
and
F
(
(
1
-
y
2
U
0
2
)
L
)
[0000] from point 306 of FIG. 3 is, approximately, 2.8 kN. The progressive optimal unconstrained damper force Φ(y) from equation (3) is calculated to be, approximately, (5.9−2.8) kN=3.1 kN whereby point 406 of FIG. 4 is obtained. Subsequent points of plot 402 can be similarly obtained for various values of y.
[0058] FIG. 5 is a graph 500 of damper force versus damper velocity for the representative motor vehicle of FIGS. 3 and 4 , showing a first plot 502 of damping force for a conventional passive damper, and a second plot 504 of progressive optimal unconstrained damper force Ψ 1 (v) as a function of damper velocity v according to the present invention.
[0059] Given FIG. 4 , Ψ 1 (v), plot 504 , can be determined from equation (5). For example, at point 406 of FIG. 4 , Φ(y) is, approximately, 3.1 kN and y=2 m/s by which v=y*r=2*0.65 m/s=1.3 m/s. From equation (5), Ψ 1 (v)=3.1/0.65 kN=4.8 kN when v=1.3 m/s, whereby point 506 of FIG. 5 is obtained. Subsequent points of plot 504 can be similarly obtained for various values of y or v.
[0060] Ψ 1 (v), plot 504 , can also be determined from equation (6). For example, for L=0.081 m, F(L) is, approximately, 6.1 kN from FIG. 3 . For V 0 =2.7 m/s and v=1.3 m/s,
[0000]
(
1
-
v
2
V
0
2
)
L
=
0.062
m
[0000] and F(0.062)=2.8 kN from FIG. 3 . From Equation (6), with r=0.65, Ψ 1 (v) is calculated to be 4.7 kN whereby point 506 of FIG. 5 is obtained. Subsequent points of plot 504 can be similarly obtained for various values of y or v.
[0061] FIG. 6 is a flow chart of an algorithm 600 for progressive optimal unconstrained damper force Φ(y) or Ψ 1 (v) according to the broadest aspect of the present invention. Algorithm 600 begins at Block 602 and then proceeds to Block 604 whereat the predetermined parameters are obtained. The predetermined parameters include, but are not limited to, m, L MAX , r, predetermined spring 204 , and V 0 (or U 0 , wherein it is understood that U 0 =V 0 /r) or L. Control then passes to Block 606 , which uses equation (4) to determine unknown V 0 or L, whereat F(L) is determined from L from Block 604 using the known suspension spring force versus displacement plot of the predetermined spring 204 as previously described. Control then passes to Block 608 whereat the progressive optimal unconstrained damper force Φ(y) is calculated and plotted using equation (3) as previously described. Control then passes to Block 610 whereat the progressive optimal unconstrained damper force Ψ 1 (v) is calculated and plotted using equation (5) or (6) as previously described. Control then passes to Block 612 whereat algorithm 600 ends.
[0062] As previously mentioned, in practice, a predetermined damper force φ(y) of damper 206 acting on the wheel center C w below a wheel center velocity u 1 , approximately 2.0 m/s, is based on ride and handling considerations for a given vehicle or vehicle model as is standard in the art, and should not be altered. The unconstrained progressive optimal damper force Φ(y) obtained from equation (3), described previously, requires some modifications to yield a progressive optimal constrained damping function Ω(y), whereby the predetermined damper force φ(y) of the damper 206 acting on the wheel center C w below a wheel center velocity of u 1 , approximately 2.0 m/s, is not altered.
[0063] If the total force, F(x)+Φ 1 (y), acting on the wheel center C w is a constant equal to C 1 , then the following condition applies:
[0000] F ( x )+Φ 1 ( y )≡ C 1 =constant (7)
[0000] by which a smooth, continuous, and monotonically increasing progressive optimal constrained damper force Φ 1 (y) of the damper 206 , as a function of the wheel center initial position x 0 and the wheel center velocity y, can be expressed as:
[0000]
Φ
1
(
y
)
=
C
1
-
F
(
U
0
2
-
y
2
2
C
1
m
+
x
0
)
,
y
≥
u
2
(
8
)
[0000] where x(0)=x 0 ≦L≦L MAX {dot over (x)}(0)=U 0 , {dot over (x)}(t 1 )=U 2 , and y={dot over (x)}. F(x) in equation (7) is the suspension spring force of the predetermined spring 204 acting on the wheel center C w for a spring displacement x, C 1 is a constant total force acting on the wheel center, and u 2 is an empirically determined velocity of the wheel center, at time t=t 1 >0, greater than, but neighboring, u 1 . As an example, if u 1 is 2.0 m/s, then u 2 may be 2.69 m/s.
[0064] Velocity u 2 is empirically determined such that the transition from the predetermined damper force φ(y) at a velocity u 1 to the progressive optimal constrained damper force Φ 1 (y) at a velocity u 2 is a damping force produced by a damping force transition function. In practice, the damping force transition function is smooth, continuous, and monotonically increasing from u 1 to u 2 and, preferably, approximates a step function. The closer u 2 is to u 1 the better the approximation to a step function and the lower the total load on the sprung mass 202 . However, u 2 should not be chosen too close to u 1 in order to avoid an abrupt change in the damping function Ω(y) (to be described later), which in turn may increase loads on the sprung mass 202 for smaller potholes than the “severe event” pothole.
[0065] Thus, the progressive optimal constrained damping function Ω(y) as a function of wheel center velocity has the following form:
[0000]
Ω
(
y
)
=
{
Φ
1
(
y
)
≡
C
1
-
F
(
U
0
2
-
y
2
2
C
1
m
+
x
0
)
,
y
≥
u
2
step
(
y
,
u
1
,
ϕ
(
y
)
,
u
2
,
Φ
1
(
y
)
)
,
u
2
>
y
>
u
1
ϕ
(
y
)
,
u
1
≥
y
≥
0
(
9
)
[0066] where step is a damping force transition function having a smooth, continuous, and monotonically increasing transition from φ(y) at velocity u 1 to Φ 1 (y) at velocity u 2 . Practically, the Haversine step function with a cubic polynomial, well known in the art, is, preferably, used as the damping force transition function.
[0067] A progressive optimal constrained damping function Ψ(v) as a function of damper velocity v can be expressed as:
[0000]
Ψ
(
v
)
=
Ω
(
y
=
v
/
r
)
r
.
(
10
)
[0068] The constant total force C 1 (or constant acceleration C=C 1 /m) is determined using the following procedure, per the algorithm 700 of FIG. 7A , wherein the equation of motion of equation (1) is numerically solved in conjunction with equation (9) for a determined u 2 , and a minimization of the sprung mass load is determined for a time at which {dot over (x)}=0 which corresponds to C 1 :
[0069] At Block 702 , equations (2) through (4) are used to determine F(L) for the case of progressive optimal unconstrained damper force as previously described.
[0070] Next, at Block 704 , F(L) is varied over an empirically determined range to obtain a C 1MAX and a C 1MIN , for example vary F(L) by plus and minus 10% to obtain C 1MAX =F(L)+0.1F(L) and C 1MIN =F(L)−0.1F(L).
[0071] Next, at Block 706 , a table is created of the variation of F(L) of Block 704 , consisting of q values wherein the first entry is designated C 11 =C 1MAX , the last value is designated C 1q =C 1MIN , an arbitrary entry is designated C 1j , and adjacent values are separated by an empirically determined amount, for example 50N.
[0072] At Block 708 , each value in the table of Block 706 is set, starting with C 11 =C 1MAX and ending with C 1q =C 1MIN , equal to −m{dot over (x)} in equation (1) and numerically solved using equation (1) in conjunction with equation (9) using a particular u 2 for the time at which {dot over (x)}=0 or y=0 (i.e., y={dot over (x)}) at which time x corresponds to the travel length of the wheel assembly and F(x) corresponds to the load on the sprung mass 202 at full jounce for that value.
[0073] In a first alternative following Block 708 , at Block 710 , the solved value corresponding to a minimum load on the sprung mass 202 at full jounce is designated as C 1 and the travel length x determined for this entry is the determined travel length L≦L MAX from which F(L) may be obtained from the graph of suspension spring force F(x) versus spring displacement x of the predetermined spring 204 (i.e., FIG. 3 ).
[0074] In a second alternative following Block 708 , at Block 712 , the load on the sprung mass 202 at full jounce for each value in the table of Block 706 , starting with C 11 =C 1MAX and ending with C 1q =C 1MIN is, plotted versus C 1 (or C, where C=C 1 /m) wherein the point on the plot whereat a minimum load on the sprung mass 202 at full jounce occurs designates C 1 and the travel length x determined for this entry is the determined travel length L≦L MAX from which F(L) may be obtained from the graph of suspension spring force F(x) versus spring displacement x of the predetermined spring 204 (i.e., FIG. 3 ).
[0075] FIG. 7B depicts an example of a graph 740 of exemplar plots pursuant to the algorithm of FIG. 7A wherein C=C 1 /m and, for example m=55.5 kN. For plot 742 , if u 2 =2.31 m/s, then C 1 is found at point 742 a , whereat C=108.1 m/s 2 and L=0.080 m. For plot 744 , if u 2 =2.69 m/s, then C 1 is found at point 744 a , whereat C=110.2 m/s 2 and L=0.081 m. For plot 746 , if U 2 =3.08 m/s, then C 1 is found at point 746 a , whereat C=113.4 m/s 2 and L=0.081 m. Other plots for different u 2 would be similarly evaluated.
[0076] Given x 0 , r, V 0 or U 0 , the wheel assembly m, and C 1 , the suspension spring force
[0000]
F
(
U
0
2
-
y
2
2
C
1
m
+
x
0
)
[0000] of the predetermined spring 204 can now be determined for any y≧u 2 from the suspension spring force versus displacement plot of the predetermined spring, as for example the plot of FIG. 3 . The progressive optimal constrained damper force Φ 1 (y) can then be obtained for any y≧u 2 . Thus, knowing φ(y), the step damping force transition function, and the progressive optimal constrained damper force Φ 1 (y), then the progressive optimal constrained damping function Ω(y) as a function of wheel center velocity y of equation (9) can be obtained for any y where 0≦y≦U 0 by which the progressive optimal constrained damping function Ψ(v) as a function of damper velocity v of equation (10) can be obtained for any v where 0≦v≦V 0 .
[0077] FIG. 7C is a flow chart of an algorithm 750 for a progressive optimal constrained damping function Ω(y) according to the preferred aspect of the present invention. Algorithm 750 begins at Block 752 and then proceeds to Block 754 whereat the predetermined parameters are obtained. The predetermined parameters include, but are not limited to, mass m of the wheel assembly 216 , L MAX , r, the predetermined spring 204 , U 0 or V 0 , the step damping force transition function, φ(y), u 1 , and x 0 .
[0078] Control then passes to Block 756 whereat C 1 and u 2 are determined as previously described. Control then passes to Block 758 whereat the progressive optimal constrained damper force Φ 1 (y) as a function of wheel center velocity is calculated as previously described and the progressive optimal constrained damping function Ω(y) as a function of wheel center velocity is determined from equation (9). Control then passes to Block 760 whereat the progressive optimal constrained damping function Ψ(v) as a function of damper velocity is determined from equation (10). Control then passes to Block 762 whereat algorithm 750 ends.
[0079] FIG. 8 is a graph 800 of damper force versus damper velocity for the representative motor vehicle of FIG. 3 , showing a first plot 802 of damping for a conventional passive damper, and a second plot 804 of progressive optimal constrained damping according to the present invention. In FIG. 8 , m=55.5 kg, r=0.65, C 1 =F(L)=6116 N, C=110.2 m/sec 2 , L=0.081 m, v 1 =1.3 m/s, v 2 =1.75 m/s, and V 0 =2.7 m/s. The predetermined damper force φ(y) is denoted by plot portion 806 of plot 802 extending from the origin, point 808 , to point 810 at which the damper velocity v 1 is 1.3 m/s and wheel center velocity u 1 is 1.3/0.65=2.0 m/s. Fourth plot 814 is the step transition function of equation (9) from point 810 to point 812 at which the damper velocity v 2 is 1.75 m/s and the wheel center velocity u 2 is 1.75/0.65=2.69 m/s. The velocity u 2 is determined as previously described. The previously mentioned Haversine step function with a cubic polynomial is used as the transition function from point 810 to point 812 .
[0080] FIG. 9 is a graph 900 of time versus total suspension load for the representative motor vehicle of FIG. 3 , showing a first plot 902 of a simulated suspension load having conventional passive damping; a second plot 904 of a simulated suspension load having progressive optimal constrained damping according to the present invention; and a third plot 906 of a simulated suspension load having progressive optimal unconstrained damping according to the present invention. Point 908 depicts the experimental peak total suspension load using a conventional prior art damper. Point 910 depicts the experimental peak total suspension load using the progressive optimal constrained damping of equation (9) according to the present invention.
[0081] As used herein, by the term a “constant total force” as applied to the force collectively provided by the spring and the damper acting on the wheel assembly during jounce according to the method of the present invention is meant a force in the general neighborhood of being constant including being exactly constant, i.e., being substantially or essentially constant.
[0082] The present invention can be implemented by any suitable damper, as for example, merely by way of nonlimiting exemplification, the damper disclosed in U.S. Pat. No. 5,706,919, to Kruckemeyer et al, issued on Jan. 13, 1998 to the assignee hereof, the disclosure of which patent is hereby herein incorporated by reference.
[0083] From the foregoing description, it is seen that the method according to the present invention enables the synthesis of a non-linear compression damping curve to more effectively control the suspension behavior while driving over roads that generate maximum wheel displacements, while maintaining good ride quality on normal roads. Advantageously, the present invention provides: 1) progressive damping (by simulation and vehicle tests) to be an effective method for reducing structural load and wheel travel at high wheel velocity events (such as potholes); 2) customization for each high wheel velocity event may have a different optimal curve depending on the peak velocity, and the optimal damping curve for one event may result in increased load for other events; 3) an analytical approach based on the nonlinear one degree of freedom mechanical system can be used for generating the optimal compression damping curve that can be subsequently tuned for vehicle production; and 4) individual optimal damping curve (for a specific initial velocity) that can be used in semi-active suspension with suspension displacement/velocity sensors.
[0084] To those skilled in the art to which this invention appertains, the above described preferred embodiment may be subject to change or modification. Such change or modification can be carried out without departing from the scope of the invention, which is intended to be limited only by the scope of the appended claims.
|
An analytical methodology for the specification of progressive optimal compression damping of a suspension system to negotiate severe events, yet provides very acceptable ride quality and handling during routine events. In a broad aspect, the method provides a progressive optimal unconstrained damping response of the wheel assembly with respect to the body. In a preferred aspect, the method provides a progressive optimal constrained damping response of the wheel assembly with respect to the body, wherein below a predetermined velocity a conventional damper force is retained.
| 1
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FIELD OF THE INVENTION
[0001] The present invention relates to the telecommunication network, and particularly to the relay device, base station and method for implementing the cooperative relay with multiple relay devices.
BACKGROUND OF THE INVENTION
[0002] Cooperative relay, as an emerging technology in the field of wireless telecommunication, has the basic idea of obtaining diversity effect via independent channels. In the cooperative relay network, the source node broadcasts the signals that it needs to transmit, and part of the relay devices deployed in the network can receive these signals, and consequently process and forward the signals. In multi-relay network, the signals forwarded by said relay devices will reach relay devices on the next hop, these relay devices will process and forward the signals again, at last, said signals reach the destination (the signal destination).
[0003] As a brand new field, the cooperative relay has limited solutions. As the cooperative relay needs to combine the signals from different relay stations, many solutions for cooperative relay require accurate synchronization and power match, which set high requirements for the real implementation of the system. Other solutions require specific channel conditions, such as the orthogonality between the channels, which increase the difficulty for design and measurement. In addition, the improvement of the performance obtained by cooperative relay is also subject to the channel condition.
SUMMARY OF THE INVENTION
[0004] The object of the invention is to provide a relay device, base station and method for implementing the cooperative relay with multiple relay devices.
[0005] According to the first aspect of the invention, there is provided a method, in a relay device in wireless telecommunication network, for performing the cooperative relay, comprising the steps of: receiving the signals from the fore level network nodes; according to the indicating information from a base station, determining the situation of the fore level network nodes and/or the next level network nodes; according to the determination result, performing normal relay process or cooperative relay process on said signals from the fore level network nodes, so as to generate the signals after relay process; sending the signals after relay process to the next level network nodes.
[0006] According to the second aspect of the invention, there is provided a relay device in wireless telecommunication network, for performing the cooperative relay, comprising: receiving means, for receiving the signals from the fore level network nodes; determining means, for according to the indicating information from a base station, determining the situations of the fore level network nodes and/or the next level network nodes; relay processing means for, according to the determination result, performing the normal relay process or cooperative relay process on the signals from the fore level network nodes, so as to generate the signals after relay process; sending means, for sending the signals after relay process to the next level network nodes.
[0007] According to the third aspect of the invention, there is provided a method, in the base station in wireless network, for supporting the cooperative relay with multiple relay devices, characterized in comprising the step of: performing cooperative detection and combination process on the branches of signals received from multiple relay devices, to generate a signal sequence after cooperative detection and combination process.
[0008] According to the fourth aspect of the invention, there is provided a base station in wireless network, for supporting the cooperative relay with multiple relay devices, characterized in comprising: a detecting and combining means, for performing cooperative detection and combination process on the branches of signals received from multiple relay devices, to generate a signal sequence after cooperative detection and combination process.
[0009] With the method and the corresponding device provided by the present invention, space diversity gain or space multiplexing gain, even both of them, can be obtained effectively. Therefore, the performance of the signals received or the consumption of relay resources can be improved considerably.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Further description of the invention is given as below referring to the figures.
[0011] FIG. 1 shows the topology of a multi-hop cooperative relay network and the corresponding frame structure according to an embodiment of the invention;
[0012] FIG. 2 shows the flowchart of the method, in a relay device, for implementing the cooperative relay in different circumstances according to an embodiment of the invention;
[0013] FIG. 3 shows the flowchart of the relay process in the method for cooperative relay in a relay device according to an embodiment of the invention, wherein, its fore level network node is a base station, while the next level network node is a mobile station;
[0014] FIG. 4 shows the flowchart of the relay process in the method for cooperative relay in a relay device according to an embodiment of the invention, wherein, its fore level network node is a base station or a mobile station, while the next level network nodes are multiple relay devices;
[0015] FIG. 5 shows the flowchart of the relay process in the method for cooperative relay in a relay device according to an embodiment of the invention, wherein, its fore level network nodes are multiple relay devices, while the next level network nodes consist in multiple relay devices or a base station;
[0016] FIG. 6 shows the flowchart of the relay process in the method for cooperative relay in a relay device according to an embodiment of the invention, wherein, its fore level network nodes are multiple relay devices, while the next level network node is a mobile station;
[0017] FIG. 7 is the diagram of the relay device for cooperative relay according to an embodiment of the invention;
[0018] FIG. 8 shows the flowchart of the method, in the base station in wireless network, for supporting the cooperative relay with multiple relay devices, according to an embodiment of the invention;
[0019] FIG. 9 is the diagram of the base station in wireless network for supporting the cooperative relay with multiple relay devices, according to an embodiment of the invention;
[0020] FIG. 10 shows the process before a relay device sending signals on the uplink according to an embodiment of the invention;
[0021] FIG. 11 a and 11 b show the course of, in the relay device or base station, processing the signals from multiple relay devices, according to an embodiment of the invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0022] Detailed description of the invention is given as below with the combination of the figures.
[0023] FIG. 1 shows the topology of a multi-hop cooperative relay network and the corresponding frame structure according to an embodiment of the invention.
[0024] As shown in the upper part of FIG. 1 , the multi-hop cooperative relay network comprises a base station (BS), multiple relay devices (relay stations, RS 1 -RS 4 ) and multiple mobile stations (MS, i.e. user equipment such as mobile phone). Wherein, since one MS is near to the BS and can communicate with the BS directly, (the quality of the signals from the MS is good enough when arriving at the BS), hence no relay is needed. However, the present invention mainly concerns the communication issues when relay is necessary between MS and BS, therefore, the description will mostly focus on the MSs which need relay.
[0025] Without loss of generality, uplink is taken as an example. MS sends signals to the next level network nodes (RS 1 and RS 2 in FIG. 1 ), before this, both RS 1 and RS 2 have got indicating information (such as the MAP information broadcasted by the BS on the downlink) from the BS directly or indirectly (forwarded by fore level relay devices level by level). Preferably, the indicating information comprises the link structure of the network, from which the relay device knows the situation of its fore level network nodes and next level network nodes. More preferably, the indicating information further comprises the specific information sequence processing method of each network node for processing its signals to be sent. After receiving the indicating information from the base station, the network nodes in adjacent network levels, such as RS 1 , RS 2 in one level and RS 3 and RS 4 in another level, can learn the specific information sequence processing method of each other, so as to perform corresponding process on the information from the other party. The detailed course thereof will be described referring to other drawings in below.
[0026] Therefore, when the signals sent by MS arrive at RS 1 and RS 2 , the two relay devices independently process the signals received and forward the processed signals respectively. Wherein, according to the different situation of the fore and next level network nodes of the relay devices, the relay processes will be different. The signals after relay processing and sent by RS 1 and RS 2 arrive at RS 3 and RS 4 via the second hop. Similarly, RS 3 and RS 4 have already got indicating information from the BS directly or indirectly (forwarded by fore level relay devices level by level). According to this indicating information, RS 3 and RS 4 independently perform relay process on their received signals and then forward the processed signals respectively. Through the third hop, the signals arrive at the BS at last. The BS then performs corresponding process on the signals from RS 3 and RS 4 , such as cooperative detection and combination, so as to retrieve the original signals sent by the MS.
[0027] It should be noted that, according to some standard such as IEEE802.16, the introduction of relay devices is transparent to the MSs, that is to say, MSs are not aware of the RSs. Therefore, in downlinks, RS 1 and RS 2 , whose next network node is an MS, should convert the format of the signals to be sent correspondingly, so that the MS can receive and identify the signals successfully. Preferably, the format after the conversion is that of the signals that a BS sends to MSs before the introduction of any RS.
[0028] The lower part of FIG. 1 shows the frame structure according to an embodiment of the invention. Wherein, the BS allocates wireless resources (e.g. time and frequency resources) to the network nodes on different levels of the network. Preferably, network nodes on the same level such as RS 1 and RS 2 can share the same network resources.
[0029] FIG. 2 shows the flowchart of the method, in a relay device, for implementing the cooperative relay in different circumstances according to an embodiment of the invention;
[0030] A cooperative relay network can be a single-hop network which has only one level of relay devices, or a multi-hop network which has two or more levels of relay devices. In FIG. 2 , as shown in the step S 101 , the relay device receives the signals from its fore level network nodes; then in the step S 102 , according to the indicating information from the base station, the relay device determines the situation of its fore or next level network nodes. With respect to different situation of fore or next level network nodes, there are four kinds of relay processes at the relay device:
[0031] 1. The fore level network node is a base station, the next level network node is a mobile station.
[0032] The specific relay process in this situation is shown in FIG. 3 , and corresponds to the transmission of downlink signals with single-hop relay. This kind of relay process is also called normal relay process. The received signals are processed by using a processing method similar as the one in single-hop scheme in the prior art (saying, doing the normal relay process). Specifically, signal regeneration process are performed on the received signals, and a signal sequence after signal regeneration are generated; then, the signal format of the signal sequence after signal regeneration will be converted, so as to generate a signal sequence after signal format conversion. This is to satisfy the requirements of some standard so that the MSs will not sense the RSs. Preferably, the format of the signal sequence after the conversion is the same as that of the signals that a BS sends to MSs before the introduction of any RS.
[0033] 2. The fore level network node is a BS or an MS, the next level network node are multiple relay devices.
[0034] The specific relay process in this situation is shown in FIG. 4 , and corresponds to the relay device on the first hop in downlink or uplink of the multi-hop relay network. Since its fore level network nodes is determined as an MS or a BS, and according to an embodiment of the invention, the MS or BS will send signals according to the method for the direct communication between a BS and an MS in the prior art, hence, after receiving the signals (the original signals from the signal source), the relay device will perform cooperative relay process on them. Specifically, the relay device performs signal regeneration process on the original signals from the fore level network node, so as to generate a signal sequence after signal regeneration. And then, by using a specific information sequence processing method such as a specific bit-level interleaving method or scrambling method that differentiates from those of other relay devices, the signal sequence after signal regeneration is processed.
[0035] 3. The fore level network nodes are multiple relay devices, the next network nodes consist in multiple relay devices or a BS.
[0036] The specific relay process in this situation is shown in FIG. 5 , and corresponds to the relay devices on any interim hop in the downlink or uplink, or to the relay devices on the last hop in the uplink of the multi-hop relay network. According to the present invention, the signals sent from a relay device to other relay devices have undergone “processing using a specific information sequence processing method”. Hence, after receiving each branch of signal sequence from other relay devices, the relay device will perform cooperative detection and combination on the arrived branches of signal sequences, so as to generate a branch of signal sequence after cooperative detection and combination. Then, the relay station will perform signal regeneration process on the branch of signal sequence after cooperative detection and combination, so as to generate a signal sequence after signal regeneration. Consequently, the signal sequence after signal regeneration will be processed with a specific information sequence processing method.
[0037] 4. The fore level network nodes are multiple relay devices, the next level network nodes is an MS.
[0038] The specific relay process in this situation is shown in FIG. 6 . As said in the contents above, the introduction of a RS is transparent to an MS. Therefore, a relay station on the last hop in downlink of the multi-hop relay network should perform cooperative detection and combination on the branches of signal sequences arrived to generate one branch of signal sequence after cooperative detection and combination. Then, the relay device will perform signal regeneration process on the branch of signal sequence after cooperative detection and combination so as to generate a signal sequence after signal regeneration. Different from the previous situation, the relay device will not process the signal sequence with a specific information sequence processing method, but convert the format of the signal sequence to generate a signal sequence after signal format conversion. The format of the signal sequence after the conversion is the same as that of the signals that a BS sends to a MS before the introduction of any RS.
[0039] The relay processes in the aforesaid situations 2-4 can be collectively called cooperative relay process.
[0040] The signals after one of the aforesaid four kinds of relay processes will be sent by the corresponding relay device to its next level network nodes in the step S 103 .
[0041] Preferably, after receiving the signals from the fore level network nodes, the relay device does a check such as Cyclic Redundancy Check (CRC) to judge if it is necessary to do some follow-up process to the signals and then forward them. This will help to improve the signal processing efficiency of the system.
[0042] FIG. 7 is the diagram of the relay device for cooperative relay according to an embodiment of the invention.
[0043] The relay device comprises a receiving means 101 , a determining means 102 , a relay processing means 103 and a sending means 104 .
[0044] The receiving means 101 is for receiving the signals from the fore level network nodes; and the determining means 102 is for, according to the indicating information from the BS, determining the situation of the fore or next level network nodes. With respect to different situation of the fore or next level network nodes, the relay processing means 103 in the relay devices is functioned as:
[0045] 1. The fore level network node is a base station, the next level network node is a mobile station.
[0046] The situation corresponds to the transmission of downlink signals with single-hop relay, which is also called normal relay process. The signals received by the receiving means 101 are processed by the relay processing means 103 by using a processing method similar as the one in single-hop scheme in the prior art (saying, doing the normal relay process). Specifically, signal regeneration process are performed on the received signals, and a signal sequence after signal regeneration are generated; then, the format of the signal sequence after signal regeneration will be converted, so as to generate a signal sequence after format conversion. This is to satisfy the requirements of some standard so that the MSs will not sense the RSs. Preferably, the format of the signal sequence after the conversion is the same as that of the signals that a BS sends to MSs before the introduction of any RS.
[0047] 2. The fore level network node is a BS or an MS, the next level network node are multiple relay devices.
[0048] The situation corresponds to the relay device on the first hop in downlink or uplink of the multi-hop relay network. Since its fore level network nodes is determined as an MS or a BS, and according to an embodiment of the invention, the MS or BS will send signals according to the method for the direct communication between a BS and an MS in the prior art, hence, after the receiving means 101 receives the signals (the original signals from the signal source), the relay processing means 103 will perform cooperative relay process on them. Specifically, the relay device performs signal regeneration process on the original signals from the fore level network node, so as to generate a signal sequence after signal regeneration. And then, by using a specific information sequence processing method such as a specific bit-level interleaving method or scrambling method that differentiates from those of other relay devices, the signal sequence after signal regeneration is processed.
[0049] 3. The fore level network nodes are multiple relay devices, the next network node(s) consist in multiple relay devices or a BS.
[0050] The situation corresponds to the relay devices on any interim hop in the downlink or uplink, or to the relay devices on the last hop in the uplink of the multi-hop relay network. According to the present invention, the signals sent from a relay device to other relay devices have undergone “processing using a specific information sequence processing method”. Hence, after receiving each branch of signal sequence from other relay devices, the relay processing means 103 will perform cooperative detection and combination on the arrived branches of signal sequences, so as to generate a branch of signal sequence after cooperative detection and combination. Then, the relay station will perform signal regeneration process on the branch of signal sequence after cooperative detection and combination, so as to generate a signal sequence after signal regeneration. Consequently, the signal sequence after signal regeneration will be processed with a specific information sequence processing method.
[0051] 4. The fore level network nodes are multiple relay devices, the next level network nodes is an MS.
[0052] As said in the contents above, the introduction of a RS is transparent to an MS. Therefore, the relay processing means 103 of a relay station on the last hop in downlink of the multi-hop relay network should perform cooperative detection and combination on the branches of signal sequences arrived to generate a signal sequence after cooperative detection and combination. Then, the relay processing means 103 will perform a signal regeneration process on the signal sequence after cooperative detection and combination so as to generate a signal sequence after signal regeneration. Different from the previous situation, the relay processing means 103 will not process the signal sequence with a specific information sequence processing method, but convert the format of the signal sequence to generate a signal sequence after signal format conversion. The format of the signal sequence after the conversion is the same as that of the signals that BS sends to a MS before the introduction of any RS.
[0053] The relay processes in the aforesaid situations 2-4 can be collectively called cooperative relay process.
[0054] The signals after one of the aforesaid four kinds of relay processes will be sent by a sending means 104 in the corresponding relay device to its next level network node(s).
[0055] Preferably, the relay device further comprises a judging means, for performing a check such as Cyclic Redundancy Check (CRC) to judge if it is necessary to do some follow-up process to the signals and then forward them.
[0056] FIG. 8 shows the flowchart of the method, in the base station in wireless network, for supporting the cooperative relay with multiple relay devices, according to an embodiment of the invention.
[0057] The method starts from the step S 201 . In the step S 201 , the BS receives the signals from its fore level network nodes. Since the present invention mainly concerns the circumstance in which relay is needed for the communication between an MS and a BS, the signals received by the BS belong to multiple relay devices, the method then enters the step S 202 .
[0058] In the step S 202 , the BS performs cooperative detection and combination on the multiple branches of signals received from the multiple relay devices, so as to generate a signal sequence after cooperative detection and combination.
[0059] FIG. 9 is the diagram of the base station in wireless network for supporting the cooperative relay with multiple relay devices, according to an embodiment of the invention.
[0060] Wherein, the BS comprises a receiving means 401 and a detecting and combining means 402 .
[0061] The receiving means 401 is for receiving the signals from the fore level network nodes. Since the present invention mainly concerns the circumstance in which relay is needed for the communication between a BS and an MS, the signals received by the BS belong to multiple relay devices. The receiving means 401 will convey the multiple branches of signals received to a detecting and combining means 402 , the latter will perform cooperative detection and combination process on the multiple branches of signals, so as to generate a signal sequence after cooperative detection and combination.
[0062] FIG. 10 shows the process before a relay device sending signals on the uplink according to an embodiment of the invention.
[0063] Wherein, in a relay device there is a Relay-specific Bit interleaver. The interleaving manner used by the interleaver is different from the interleaving manner used by the interleavers in other relay devices. The interleaver is responsible for interleaving the encoded bit stream. Before the transmitting antennas, there is a Symbol mapping/multiplexing module, which is for mapping the symbols to the transmitting antennas, or for performing spatial multiplexing and then mapping the signals to multiple transmitting antennas. The kind of the gain the system can finally obtain depends on whether the signals that multiple relay devices send by using the same resource block (e.g. time and frequency) are the same. According to an embodiment of the invention, there are diversity gain and multiplexing gain.
[0064] Preferably, for the better performance, it is possible to add a module for spectrum spreading between the FEC (a kind of channel coding) module and the interleaving module, so as to achieve the spreading gain and speed match.
[0065] FIG. 11 a and 11 b show the course of, in the relay device or base station, processing the signals from multiple relay devices, according to an embodiment of the invention.
[0066] Wherein, the functions of MIMO and multi-use detection have been integrated in the Macro MIMO Detector (Macroscopic Multiple Input Multiple Output). After cooperative detection and combination, each of the interleavers and de-interleavers are in correspondence with a corresponding relay device, that is to say they have the same interleaving manner. The signals after combination will experience channel decoding in the Channel Decoder, so that the original signal sequence can be retrieved for follow-up operation.
[0067] Other means such as channel decoder can be standardized soft-in-soft-out detector.
[0068] Preferably, for the better performance (achieving spreading gain and speed match), a corresponding spreading (de-spreading) module can be added into the structure shown in the figure, for spreading gain and speed match.
[0069] Moreover, according to an embodiment of the invention, a relay device can be equipped with multiple transmitting antennas, two or more relay devices work cooperatively on the same level of the network by sharing radio resources.
[0070] Although the embodiments of the present invention have been described above, it is understandable by those skilled in the art that various modifications can be made without departing from the scope and spirit of the scope of the attached claims.
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The invention provides a method and device for cooperative relay with multiple relay stations in the wireless telecommunication network. The invention is proposed to improve the quality of relayed signals, reduce the resources needed for relaying and solve the problems when performing the switch between relay devices. The method and device according to the invention are characterized in that, the received signals are processed according to the indicating information from a BS, before sending them to the next level network nodes. Compared with the prior art, the present invention can achieve better spatial diversity gain or spatial multiplexing gain, even both of them. Further, the present invention does not require a high level synchronization. Therefore, the performance of the signals received can be considerably improved, the resources needed for relaying are also reduced. Further, the present invention is very practical.
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CROSS REFERENCES TO RELATED APPLICATIONS
The present application claims priority to U.S. Provisional Patent Application No. 61/902,036, filed on Nov. 8, 2013, and is a continuation in part of U.S. patent application Ser. No. 14/163,946, filed on Jan. 24, 2014, which claims priority to U.S. Provisional Patent Application No. 61/893,728, filed on Oct. 21, 2013, and which is a continuation-in-part of U.S. patent application Ser. No. 14/033,218, filed on Sep. 20, 2013, which is a continuation-in-part of U.S. patent application Ser. No. 13/923,571, filed on Jun. 21, 2013, which is a continuation-in-part of U.S. patent application Ser. No. 13/778,958, filed on Feb. 27, 2013, which claims priority to U.S. Provisional Patent Application No. 61/727,608, filed on Nov. 16, 2012, and U.S. patent application Ser. No. 14/163,946 is also a continuation-in-part of U.S. patent application Ser. No. 13/766,658, filed on Feb. 13, 2013, which claims priority to U.S. Provisional Patent Application No. 61/746,348, filed on Dec. 27, 2012, the disclosure of each of which is hereby incorporated by reference in its entirety herein.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a golf club head. More specifically, the present invention relates to a weight for a golf club head that can be adjusted along one or more channels.
2. Description of the Related Art
The ability to adjust center of gravity location and weight in the head of driving clubs is useful for controlling performance of the golf club. The prior art includes several different solutions for adjustable weighting, but these solutions do not optimize weight adjustment. There is a need for a weighting mechanism that allows for simple and flexible center of gravity (CG) and moment of inertia (MOI) adjustability.
BRIEF SUMMARY OF THE INVENTION
The present invention is a novel way of working with adjustable products. The present invention allows consumers to easily move and fix a weight at any location within one or more channels disposed in the golf club head in such a way to maximize aesthetic appearances while preserving the function of the movable weight. The objective of this invention is to provide an adjustable weight with minimal or no effect on appearance at address while maximizing the ability of the weight to adjust center of gravity height. Additional goals include minimizing the fixed component of the structure dedicated to the weighting system and also minimizing any potential effect on impact sound. Yet another object of the present invention is an adjustable weighting feature for lateral or vertical center of gravity control which is placed to maximize effectiveness and may be entirely concealed from view at address.
One aspect of the present invention is a golf club head comprising a body comprising a face and a sole, a crown, a track, a mechanical fastener, and a first weight comprising a lower recess, wherein the sole comprises a channel having at least two walls and a floor, wherein the track is at least partially disposed within the channel, wherein the weight receives an upper portion of the track within the lower recess, and wherein the weight is reversibly affixed to the track with the mechanical fastener. The channel may comprise a floor and a track opening, the track may comprise a lower edge sized to fit within the track opening, and the track may be permanently affixed to the body within the channel. In some embodiments, the body may be integrally cast from a metal material, the track may be composed of a metal material, and the crown may be composed of a composite material.
In one embodiment, the weight may comprise an upper recess, a threaded bore that connects the upper recess with the lower recess, and two hooked lower edges, the mechanical fastener may comprise a threaded extension sized to fit within the threaded bore, and the track may comprise a I-shaped cross section. In some embodiments, the body may comprise a plurality of internal ribs, each of which may be affixed to the floor of the channel. In another embodiment, the golf club head may further comprise a stopper sized to it within the channel and over the track, which may prevent the weight from detaching from the track. In some embodiments, the stopper may be composed of a material selected from the group consisting of plastic, composite, and rubber, while in other embodiments the stopper may be composed of a material selected from the group consisting of stainless steel, titanium alloy, aluminum alloy, and tungsten alloy.
In one embodiment, the track may comprise a first end having a first width and a second end having a second width, and the first width may be smaller than the second width. In another embodiment, the golf club head may further comprise a second weight, which may comprise a lower recess sized to receive an upper portion of the track. In some embodiments, the track may be welded to the body. In yet another embodiment, the golf club head may comprise an adjustable hosel assembly, and may be selected from the group consisting of a driver-type head, a fairway wood-type head, an iron-type head, a hybrid-type head, and a putter-type head.
Another aspect of the present invention is a wood-type golf club head comprising a metal body comprising a face, a hosel, a heel side, a toe side, and a sole, a composite crown, a metal track comprising a lower edge, a first end having a first width, a second end having a second width, and an upper portion having an upper surface, a screw comprising a head and a threaded extension, a weight comprising an upper recess, a lower recess sized to receive the upper portion of the track, and a threaded bore connecting the upper recess with the lower recess, and a stopper, wherein the sole comprises a channel having at least two walls, a floor, and a track opening, wherein the channel extends from the heel side to the toe side, wherein the lower edge of the track fits within the track opening, wherein the weight is reversibly fixed to the track with the screw, and wherein the stopper prevents the weight from disengaging from the track. In some embodiments, the track may be welded to the body, or may comprise a protective cover. In other embodiments, the body may comprise a plurality of ribs, and each of the ribs may be affixed to an interior surface of the channel floor. In yet another embodiment, the track may be composed of anodized aluminum.
Having briefly described the present invention, the above and further objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a sole perspective view of a preferred embodiment of the present invention.
FIG. 2 is a cross-sectional view of the embodiment shown in FIG. 1 along lines 2 - 2 .
FIG. 3 is a first exploded view of the embodiment shown in FIG. 1 .
FIG. 4 is a second exploded view of the embodiment shown in FIG. 1 .
FIG. 5 is an assembled view of the embodiment shown in FIG. 3 .
FIG. 6 is sole perspective view of the embodiment shown in FIG. 5 .
FIG. 7 is another sole perspective view of the embodiment shown in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
The design approaches described herein are based on a construction used in a driver head characterized by a composite crown adhesively bonded to a cast titanium body. This particular construction approach permits the crown configuration to be adapted to the inventive weighting scheme with minimal impact on weight and function. However, the weighting embodiments disclosed herein can be used with other constructions, including all titanium, all composite, and a composite body with metal face cup. The embodiments may also work in conjunction with at least one adjustable weight port on the sole, crown, and/or other part of the driver head. Shifting weight along the channel described herein gives a user control of the golf club head's center of gravity location.
A preferred embodiment of the present invention is shown in FIGS. 1-7 . The golf club head 10 comprises a channel 20 disposed within the sole 14 of the golf club head 10 , though in alternative embodiments the channel 20 may be disposed in a ribbon or skirt portion and/or in the crown 12 of the golf club head 10 . The channel 20 preferably is integrally cast with the sole 14 , hut in alternative embodiments may be separately formed and then permanently affixed the sole 14 or other portions of the golf club head 10 . The channel 20 extends from a heel side 16 of the club head proximate a hosel 11 , which preferably includes adjustability features, to a toe side 18 of the golf club head 10 , and is supported within the head 10 with a series of ribs 26 . The channel 20 includes a track 30 , which protrudes from a floor 25 of the channel 20 , has a T-shaped cross section, and has a narrow first end 31 and a wider second end 33 . As shown in FIG. 6 , the width of the track 30 abruptly tapers to the narrow first end 31 so that most of the length of the track 30 can be used as a guide for the weight 40 , which can be removed from the track 30 by sliding the weight 40 off of the narrow first end 31 .
A weight 40 , which is significantly smaller in length than the channel 20 and slightly smaller in width than the channel 20 , is sized to fit within the channel 20 and includes a T-shaped lower recess 45 sized to receive the upper, T-shaped part of the track 30 . When the track 30 is engaged with the lower recess 45 of the weight 40 as shown in FIG. 2 , the weight can slide to any point along the track 30 . A stopper 60 is removably affixed over the narrow first end 31 of the track 30 within the channel 20 with semi-permanent adhesives, mechanical fasteners, or other means known to a person skilled in the art, to prevent the weight 40 from becoming disengaged from the track 30 at the narrow first end 31 , and thus the channel 20 , during use. In an alternative embodiment, the stopper 60 may be permanently affixed to the head 10 so that the weight 40 is permanently retained within the channel 20 on the track 30 . The stopper 60 may be made of a lightweight material such as composite, rubber, or another polymer, but preferably functions as another weight and is composed of a denser material such as titanium, steel, or tungsten.
When a user has adjusted the weight's 40 location along the track to a desired point, he or she can removably fix the weight 40 to that location with a screw 50 , which is received in an upper recess 42 of the weight 40 . The threaded portion 55 of the screw 50 extends through a threaded bore 44 that connects the upper recess 42 to the lower recess 45 of the weight 40 and; when it is fully screwed into the weight 40 , makes contact with an upper surface 32 of the track 30 . When the threaded portion 55 of the screw 50 makes contact with the track 30 , it pushes the weight 40 away from the track 30 such that the hooked, lower edges 46 a , 46 b of the weight 40 press against the underside of the track 30 , thereby reversibly locking the weight 40 onto the track 30 . The upper surface 32 of the track 30 preferably includes a protective cover 34 , which may be made from a material including, but not limited to, a rubber, felt, or a co-molded polymer, so that neither the screw 50 nor the track 30 becomes damaged when they make contact with each other. In an alternative embodiment, the upper surface 32 of the track 30 is protected with u plate (not shown), which may be located within the lower recess 45 of the weight 40 and/or affixed to a lower surface of the threaded portion 55 of the screw 50 and be pressed towards the track 30 when the screw 50 is tightened by a user.
The golf club head 10 of the present invention preferably is assembled as shown in FIGS. 3-7 . First, a body 19 comprising the hosel 11 , sole 14 , and face 15 is cast from a metal material, which preferably is a titanium alloy, hut in other embodiments may be steel. The channel 20 is integrally cast with the body 19 , and then aback opening 22 is cut into the floor 25 of the channel 20 using a laser, a cutter, or any other means known to a person skilled in the art. The track 30 is cast or otherwise formed from a metal material, preferably an anodized aluminum alloy, and the lower edge 36 of the track 30 is inserted into the track opening 22 and permanently affixed there via welding, soldering, brazing, or another means known to a person skilled in the art, as shown in FIGS. 5 and 6 . The track opening 22 preferably extends into the ribs 26 as shown in FIG. 3 so that the lower edge 36 of the track 30 is supported by the ribs 26 when it is inserted into the track opening 22 . In alternative embodiments, the track 30 may be affixed to the channel 20 with one or more mechanical fasteners, an adhesive, clip or snap mechanisms, or one or more of the mechanisms disclosed in U.S. Pat. No. 7,147,573 to DiMarco and U.S. Pat. No. 7,166,041 to Evans, the disclosure of each of which is hereby incorporated by reference in its entirety herein.
Once the track 30 is affixed to the body 19 , the weight 40 is slid onto the track 30 via its narrow first end 31 , which is then blocked off with the stopper 60 as shown in FIG. 7 to prevent the weight 40 from disengaging from the body 19 . The crown 12 may be affixed to the body 19 at any time after the track 30 is affixed to the body 19 , and preferably is permanently attached to the body 19 with an adhesive material. The crown 12 is formed from a light-weight material, preferably a non-metal material such as a composite, which may be selected from any of the composite materials disclosed in U.S. Pat. No. 8,460,123 and U.S. patent application Ser. No. 13/912,994, the disclosure of each of which is hereby incorporated by reference in its entirety herein.
The weight 40 disclosed in connection with the preferred embodiment shown herein may have any of the constructions disclosed in U.S. patent application Ser. No. 14/033,218, and may also be added to and removed from the golf club head 10 as disclosed in that application. Similarly, the channel 20 disclosed herein may have any of the configurations disclosed in U.S. patent application Ser. No. 13/656,271, the disclosure of which is hereby incorporated by reference in its entirety herein, and the channel 20 disclosed herein may disposed anywhere on a golf club head 10 , including the sole, 14 , crown 12 , face, 15 , and ribbon portions. Though the embodiment disclosed herein is provided in a driver, the adjustable weighting configuration shown herein may also be used with other type of golf clubs, including fairway woods, irons, hybrids, and putters.
In other embodiments, the golf club head 10 may have a multi-material composition such as any of those disclosed in U.S. Pat. Nos. 6,244,976, 6,332,847, 6,386,990, 6,406,378, 6,440,008, 6,471,604, 6,491,592, 6,527,650, 6,565,452, 6,575,845, 6,478,692, 6,582,323, 6,508,978, 6,592,466, 6,602,149, 6,607,452, 6,612,398, 6,663,504, 6,669,578, 6,739,982, 6,758,763, 6,860,824, 6,994,637, 7,025,692, 7,070,517, 7,112,148, 7,118,493, 7,121,957, 7,125,344, 7,128,661, 7,163,470, 7,226,366, 7,252,600, 7,258,631, 7,314,418, 7,320,646, 7,387,577, 7,396,296, 7,402,112, 7,407,448, 7,413,520, 7,431,667, 7,438,647, 7,455,598, 7,476,161, 7,491,134, 7,497,787, 7,549,935, 7,578,751, 7,717,807, 7,749,096, and 7,749,097, the disclosure of each of which is hereby incorporated in its entirety herein.
From the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present invention has been described in association with a preferred embodiment thereof, and other embodiments illustrated in the accompanying drawings, numerous changes, modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims. Therefore, the embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims.
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A golf club head comprising a means for adjusting the location of the center of gravity, and the bias of the golf club head, is disclosed herein. In particular, the golf dub head of the present invention comprises a channel that includes a track. A slidable weight is movable along the track and is reversibly affixed to various locations along the track with a mechanical fastener. The track has a narrow end by which the slidable weight is threaded onto the track, and the narrow end is covered with a stopper to prevent the weight from disengaging from the track, and thus the channel.
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RELATED APPLICATION
[0001] This application is a continuation application of PCT/EP2008/003574 filed May 3, 2008, the entire specification of which is incorporated herein by reference.
FIELD OF THE DISCLOSURE
[0002] The present invention relates to a connecting means for connecting a first component and a second component, and in particular, for connecting furniture parts or machine parts, comprising
a first connecting element arranged on the first component in the connected state of the components and a second connecting element arranged on the second component in the connected state of the components, wherein at least one of the connecting elements comprises a curved bearing surface which is in the form of an arc of a circle in longitudinal section.
BACKGROUND
[0004] Such connecting means are known from AT 373 046 or DE 28 16 134 A1 for example. In accordance with AT 373 046, the connecting elements each comprise a hook-shaped head part protruding towards the other connecting element, wherein the two head parts are pushed laterally into one another for the purposes of connecting the connecting elements. In accordance with DE 28 16 134 A1, the connecting elements each comprise a hook which engages behind a hook of the respective other connecting element in the connected state of the connecting elements, wherein the two connecting elements are pushed against each other in parallel with the contact areas of the mutually engaging components for the purposes of establishing a connection.
[0005] The connecting means in accordance with AT 373 046 or DE 28 16 134 A1 must be secured by either additional fixing screws or an adhesive in order to guard against unintentional release, or else the connecting elements are latched together in such a way that they can no longer be released from one another.
[0006] DE 196 04 243 C2 discloses a fitting for connecting components, said fitting consisting of two half-fittings which are each fixed to a respective one of the components that are to be connected and comprise elements that are adapted to be brought into engagement with one another for establishing the connection between the components, wherein each of the half-fittings comprises a section in the form of a segment of a circle having self-cutting protruding edges so that each half-fitting is adapted to anchor itself in the relevant component by virtue of being driven into its respectively associated component along the self-cutting edges.
[0007] The connection of the two components established with the aid of this fitting can only be released, if at all, with great difficulty. In addition, there is a danger with the fitting in accordance with DE 196 04 243 C2 that the lateral walls of the respective component could break away when driving-in the half-fittings as a result of the forces arising due to the protruding self-cutting edges.
SUMMARY OF THE INVENTION
[0008] The object of the present invention is to provide a connecting means of the type mentioned hereinabove which will enable two components to be connected to one another by means of a reliably releasable connection without giving rise to the danger of damaging the two components during the assembly process.
[0009] In accordance with the invention, this object is achieved in the case of a connecting means comprising the features indicated in the first part of Claim 1 in that the first connecting element and the second connecting element are connected to one another in releasable manner in the connected state of the components and in that at least the first connecting element comprises a housing and at least one holding element which is moveable relative to the housing of the first connecting element and which, in a holding position, cooperates with the second connecting element in such a way that a relative movement of the first connecting element and the second connecting element along a direction of the connection is prevented, and which, in a release position, permits a relative movement of the first connecting element and the second connecting element along the direction of the connection,
wherein at least one holding element is movable from the holding position into the release position and/or from the release position into the holding position by an action taken outside the connecting means and wherein the housing of the first connecting element comprises a curved bearing surface which is in the form of an arc of a circle in longitudinal section, and a substantially flat bearing surface which is located opposite the aforesaid bearing surface and is arranged to abut the second connecting element.
[0012] The concept underlying the solution in accordance with the invention is that the connection of the two connecting elements is not established by means of a relative displacement of the two connecting elements as a whole but rather, it is effected by means of a relative movement of the holding element relative to a housing of the first connecting element from the release position into the holding position. As an alternative or in addition thereto, the connection between the connecting elements can be released by means of a movement of the holding element relative to the housing of the first connecting element from the holding position into the release position.
[0013] Due to the fact that at least one of the connecting elements comprises a curved bearing surface which is in the form of an arc of a circle in longitudinal section, this bearing surface can slide on a groove base surface, which is likewise in the form of an arc of a circle in longitudinal section, of a groove provided in one of the components, whereby the orientation of the connecting element concerned relative to the other respective connecting element can be changed within certain limits in the course of connecting the connecting elements in order to compensate for the positional tolerances of the grooves in which the connecting elements are arranged, and/or for the manufacturing tolerances of the connecting elements.
[0014] Due to this additional degree of freedom of movement, further corrections with respect to their mutual positioning are possible when assembling the two components, this thereby significantly reducing the need for precision with regard to the location of the grooves in the components and thus leading to it being considerably easier for the user to use.
[0015] When the connecting elements are locked together due to the movement of the holding element into the holding position, then, due to the tensile forces which act on the connecting elements in a direction of connection that is oriented transversely and preferably perpendicularly to the bearing surfaces of the connecting elements, so much friction will be activated that the aforementioned degrees of freedom of movement are annulled and an extremely firm connection between the components that are to be connected is established.
[0016] The connecting elements of the connecting means in accordance with the invention are placed into pre-existing grooves in the components so that it is not necessary to exert a large amount of force in order to insert the connecting elements into the components and consequently, there is no danger of damage to these components.
[0017] In contrast thereto, when inserting the half-fittings of the fitting known from DE 196 04 243 C2 into the components, holding grooves for the half-fittings must first be reamed out by means of the self-cutting protruding edges by forcing the half-fittings into the components. For this purpose, it is necessary to exert quite a substantial amount of force. Furthermore, the self-cutting protruding edges must be geometrically optimised for the self-cutting action, and in particular, they need to be sufficiently thin in order to make it possible to force out the reamed-out material. Furthermore, when driving the half-fittings into the components, material can easily be chipped off the outer edges of the component, especially when the half-fittings are being driven-in at the edge of the component. In the case of solid materials such as a hardwood for example, the process of driving-in the half-fittings is extremely difficult; in the case of other materials such as plexiglass for example or in the case of metallic materials, a self-cutting process for driving-in the half-fittings fails completely. Furthermore, after being driven into the respective component, the half-fittings are stuck immovably therein and can no longer be shifted along the holding groove in order to enable corrections in the positioning thereof to be made and thus compensation for tolerances to be effected.
[0018] When the holding element of the connecting means in accordance with the invention has been moved from the holding position into the release position, the connecting elements can be moved away from each other in a direction of connection that is oriented perpendicularly to the bearing surfaces of the connecting elements with which the connecting elements abut one another in the connected state of the components, without the connecting elements having to be previously moved relatively to each other in a direction parallel to the bearing surfaces.
[0019] In a preferred embodiment of the invention, the substantially flat bearing surface of the first connecting element is able to abut a likewise substantially flat bearing surface of the second connecting element.
[0020] The substantially flat bearing surface of the first connecting element and/or that of the second connecting element is preferably oriented substantially parallel to contact areas of the components with which the components abut one another in the connected state of the components.
[0021] Furthermore, the curved bearing surface and the substantially flat bearing surface of the first connecting element and/or the second connecting element are oriented substantially perpendicularly to the direction of the connection in the connected state of the components.
[0022] In the connected state of the components, the first connecting element can be arranged in a groove in the first component and the second connecting element can be arranged in a groove in the second component, and the curved bearing surface of one of the connecting elements, which is in the form of an arc of a circle in longitudinal section, can slide on a groove base surface of one of the grooves provided in the components that is likewise in the form of an arc of a circle in longitudinal section.
[0023] In particular, the curved bearing surface of at least one connecting element can be substantially in the form of a section of the surface of a regular cylinder.
[0024] In a preferred embodiment of the invention, provision is made for at least one holding element to be held such as to be pivotal on the first connecting element.
[0025] In order to effect the connection of the two connecting elements in the holding position of the holding element, provision may be made for at least one holding element to have a first holding contour which engages behind a second holding contour provided on the second connecting element in the holding position.
[0026] The first holding contour and/or the second holding contour can be formed such as to be arc-shaped.
[0027] In particular, provision may be made for the first holding contour and the second holding contour to be formed such that they are not mutually concentric so that the two connecting elements are pulled against each other when moving the holding element from the release position into the holding position.
[0028] Until now, no detailed indications have been given as to the manner in which the holding element is movable from the holding position into the release position or in the reverse direction by means of an action occurring outside the connecting means.
[0029] For example, provision may be made for at least one holding element to be movable from the holding position into the release position and/or from the release position into the holding position by means of a mechanical actuating means that can be moved into engagement with the holding element from outside the connecting element.
[0030] For this purpose, it is expedient if at least one holding element comprises a seating for an actuating section of a mechanical actuating means.
[0031] In particular, provision may be made for at least one holding element to comprise a seating for a polygonal key, an Allen key and/or a screwdriver.
[0032] In order to enable the mechanical actuating means to act on the holding element, provision may be made for the first connecting element to comprise a housing having a passage opening for the passage of a mechanical actuating means to a holding element.
[0033] In particular, provision may be made for the housing to comprise a side wall which extends transversely with respect to the curved bearing surface of the first connecting element, and the passage opening is arranged in this side wall.
[0034] As an alternative thereto, provision may also be made for the passage opening to be arranged in the curved bearing surface of the first connecting element.
[0035] In a special embodiment of the invention, provision may be made for at least the first connecting element to comprise at least two holding elements which are held such as to be pivotal on the first connecting element.
[0036] In order to ensure the connection of the two connecting elements in the holding position of the holding elements, provision may be made for at least two holding elements to each engage behind a respective restraining element which is arranged on the second connecting element in the holding position.
[0037] In order to enable the holding elements to be pivoted from the release position into the holding position, provision may be made, in particular, for a support region of a first holding element and a support region of a second holding element to be movable relative to each other by means of a spreading mechanism.
[0038] Such a spreading mechanism could comprise a magnet element which is adapted to be driven such that it moves within the connecting means by means of a time varying magnetic drive field which acts on the magnet element from outside the connecting means.
[0039] In a preferred embodiment of the invention, provision is made for the spreading mechanism to comprise at least two spreading elements which are in engagement with one another.
[0040] In particular, the spreading elements may be held in engagement with one another by means of two mutually complementary threads.
[0041] It is particularly expedient, if at least one of the spreading elements is adapted to be driven into rotational movement relative to the other spreading element by means of the magnet element.
[0042] In particular, the magnet element may comprise a driver element which acts on a driven element on one of the spreading elements.
[0043] Furthermore, provision may be made in a special embodiment of the invention for at least one holding element to have a thread.
[0044] Provision may be made for at least one holding element to be in engagement with a restraining element in the holding position, wherein said restraining element is arranged on the second connecting element and the restraining element has a thread that is complementary to the thread of the holding element.
[0045] In order to facilitate the process of bringing the holding element into engagement with the restraining element, provision may be made for the connecting means to comprise at least one resilient element, and in particular a spring, by means of which the holding element and the restraining element are biased against each other.
[0046] Furthermore, a thread axis of the holding element can be oriented such as to be substantially parallel to the direction of the connection in the connected state of the components.
[0047] In a special embodiment of the invention, provision may be made for the connecting means to comprise a magnet element which can be driven into a rotational movement within the connecting means by means of a time varying magnetic drive field that acts on the magnet element from outside the connecting means.
[0048] In particular, by means of such a magnet element, at least one holding element can be adapted to be driven into a rotational movement relative to the housing of the first connecting element.
[0049] Hereby, the magnet element may comprise a driver element which acts on a driven element on the holding element.
[0050] In order to enable shearing stresses to be removed as well by means of the connection between the connecting elements, it is of advantage if at least one of the connecting elements comprises at least one insertible projection and if the other respective connecting element comprises at least one seating pocket for accommodating the insertible projection in the connected state of the components. Thereby, additional dowel pins such as are necessary with most other connecting means can be dispensed with.
[0051] If at least one seating pocket extends to a greater extent in the longitudinal direction of the connecting means than the insertible projection accommodated therein, then this offers the advantage that the first connecting element and the second connecting element are mutually displaceable in the longitudinal direction in order to enable tolerances in the connection between the components to be compensated for in this manner.
[0052] In order to obtain a particularly effective anchoring of at least one of the connecting elements in the associated component, provision may be made for at least one of the connecting elements to be provided with at least one holding projection which comprises a curved supporting surface that is in the form of an arc of a circle in longitudinal section.
[0053] With the aid of this curved supporting surface, the holding projection can be supported on a likewise curved undercut surface of an undercut section of a groove in the associated component, whereby this undercut surface is likewise in the form of an arc of a circle in longitudinal section and has the same radius of curvature as the curved supporting surface of the holding projection. A positive connection between the component and the connecting element is produced as a result of the engagement between the holding projection and the undercut section of the groove.
[0054] The holding projection of the connecting means in accordance with the invention is preferably formed such as not to be self-cutting.
[0055] Rathermore, the holding projection is provided for reason that it can be slid into a groove having an undercut section in the component concerned in the longitudinal direction of the groove, said groove having been produced prior to the insertion of the connecting element into the component. In this case, the holding projection can be pushed into the undercut section of the groove in the tangential direction using just a small amount of force so that the connecting element still has a certain degree of freedom of movement in this direction and thus corrections with respect to their mutual positioning are still possible when connecting the components.
[0056] In particular, the holding projection may comprise stub-like ends and/or have rounded-off, bevelled edges at its end regions.
[0057] The cross-sectional area of a non self-cutting holding projection may be of any arbitrary size in order to increase the mechanical stability of the holding projection.
[0058] In particular, the cross-sectional area of the holding projection can amount to at least 1 mm 2 .
[0059] The holding projection may comprise a substantially rectangular or a substantially trapezoidal cross section.
[0060] As an alternative or in addition thereto, provision may be made for at least one holding projection to taper with increasing spacing from a base body of the respective connecting element.
[0061] On the other hand, provision may be made for at least one holding projection to taper with decreasing spacing from a base body of the respective connecting element.
[0062] As an alternative or in addition thereto, it is also conceivable for at least one holding projection to have a cross section having an outer contour which is curved at least in sections thereof.
[0063] In a preferred embodiment of the invention, provision is made for the surface of at least one holding projection to be substantially flush with the adjoining curved bearing surface of the respective connecting element. Thus, in this case, the holding projection is arranged on the outermost edge of the associated connecting element facing the groove base.
[0064] As an alternative or in addition thereto, provision may also be made for at least one holding projection to be arranged such that it is offset with respect to the curved bearing surface of the respective connecting element. Thus, in particular, the holding projection may comprise a smaller radius of curvature than the curved bearing surface of the respective connecting element.
[0065] Furthermore, provision may be made for several holding projections having differing radii of curvature to be arranged on the same connecting element. In particular a plurality of holding projections having differing radii of curvature can be arranged on the same side of the respective connecting element.
[0066] As an alternative or in addition to a process of anchoring the connecting elements by means of one or more holding projections, provision may also be made for at least one of the connecting elements to be provided with at least one anchoring element for fixing the connecting element concerned to a groove base of a groove provided in one of the components.
[0067] Furthermore, provision may be made for at least one of the connecting elements to be provided with at least one anchoring screw for fixing the connecting element concerned to one of the components.
[0068] Furthermore, the present invention relates to a method of producing a connection between a first component and a second component, in particular, a connection between furniture parts or machine parts.
[0069] The object of the present invention is to provide a method which is such as to enable two components to be connected together in reliably releasable manner without giving rise to the danger of damage to one of the components.
[0070] This object is achieved by a method which comprises the following method steps:
producing a respective groove in a contact area of the first component and in a contact area of the second component, wherein at least one of the grooves comprises a curved groove base surface which is in the form of an arc of a circle in longitudinal section; inserting a first connecting element into the groove in the first component and a second connecting element into the groove in the second component, wherein at least the first connecting element comprises a housing which has a curved bearing surface that is in the form of an arc of a circle in longitudinal section and also has a substantially flat bearing surface that is located opposite said curved bearing surface and is placed on the second connecting element; connecting the first connecting element and the second connecting element in releasable manner by moving, by means of an action taken outside the first connecting element, at least one holding element that is arranged on the first connecting element and is moveable relative to a housing of the first connecting element from a release position in which the holding element permits a relative movement of the first connecting element and the second connecting element along the direction of connection into a holding position in which the holding element prevents a relative movement of the first connecting element and the second connecting element along the direction of the connection.
[0074] Special embodiments of the method in accordance with the invention form the subject matter of Claims 42 to 65 , the advantages thereof having already been expounded hereinabove in connection with the special embodiments of the connecting means in accordance with the invention.
[0075] Further features and advantages of the invention form the subject matter of the following description and the graphical illustration of exemplary embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0076] FIG. 1 shows a schematic perspective illustration of two components that are to be connected whilst they are in the unconnected state, wherein each component comprises a respective groove having a central base section and two arc-shaped undercut sections protruding from the base section;
[0077] FIG. 2 a schematic perspective illustration corresponding to FIG. 1 in which the non visible edges are additionally drawn-in in broken lines;
[0078] FIG. 3 a schematic cross section through the first component depicted in FIGS. 1 and 2 in the vicinity of an access boring;
[0079] FIG. 4 a schematic side view of the first component depicted in FIGS. 1 and 2 ;
[0080] FIG. 5 a schematic perspective illustration of a connecting means for connecting the two components depicted in FIGS. 1 to 4 , which comprises a first connecting element having a holding element and a second connecting element having a seating for the holding element;
[0081] FIG. 6 a schematic perspective illustration corresponding to FIG. 5 in which the non visible edges are additionally drawn-in in broken lines;
[0082] FIG. 7 a schematic perspective side view of the components connected by the connecting means depicted in FIGS. 5 and 6 ;
[0083] FIG. 8 a schematic perspective illustration of the two components that are to be connected together whilst they are in the unconnected state wherein a respective one of the connecting elements is inserted into the groove in each component;
[0084] FIG. 9 a schematic perspective illustration corresponding to FIG. 8 in which the non visible edges are additionally drawn-in in broken lines;
[0085] FIG. 10 a schematic perspective illustration of a groove cutting device including a displacement device, wherein a rotatable milling disk of the groove cutting device is withdrawn into a housing of the groove cutting device;
[0086] FIG. 11 a schematic perspective illustration of the groove cutting device corresponding to FIG. 10 wherein the rotatable milling disk has been partly extended from the housing of the groove cutting device;
[0087] FIGS. 12 to 15 a sequence of schematic cross sections through a component in which a groove incorporating a base section and two undercut sections protruding from the base section is being milled by means of the groove cutting device depicted in FIGS. 10 and 11 ;
[0088] FIG. 16 a schematic perspective illustration of a groove cutting device incorporating a T-groove cutter and a guidance device for guiding the groove cutting device in a pre-milled guide groove;
[0089] FIGS. 17 , 19 and 21 schematic side views of a component in which a groove having a base section and two arc-shaped undercut sections protruding from the base section is milled by means of the groove cutting device depicted in FIG. 16 ;
[0090] FIGS. 18 , 20 and 22 schematic cross sections corresponding to FIGS. 17 , 19 and 21 through the groove formed in the component;
[0091] FIG. 23 a schematic side view of the first component into the groove of which the first connecting element is inserted;
[0092] FIG. 24 a schematic side view of both components with inserted connecting elements which are to be moved towards one another;
[0093] FIG. 25 a schematic side view of the components with the contact areas thereof lying close together and a polygonal key which is in engagement with the holding element of the first connecting element through an access boring;
[0094] FIG. 26 a schematic side view of the two components and the polygonal key by means of which the holding element is moved from a release position into a holding position;
[0095] FIG. 27 a schematic side view of a housing of the first connecting element;
[0096] FIG. 28 a schematic section through the housing of the connecting element depicted in FIG. 27 , along the line 28 - 28 in FIG. 27 ;
[0097] FIGS. 29 to 31 schematic cross sections corresponding to FIG. 28 through the housing of the connecting element depicted in FIG. 27 , wherein holding projections of the housing each have different profiles;
[0098] FIG. 32 a schematic perspective illustration of a second embodiment of the connecting means in which the holding part of the first connecting element is in the form of a threaded element which can engage in a restraining element provided on the second connecting element;
[0099] FIG. 33 a schematic perspective illustration corresponding to FIG. 32 in which the non visible edges are additionally drawn-in in broken lines;
[0100] FIG. 34 a schematic side view of the two components which are connected together by means of the second embodiment of the connecting means;
[0101] FIG. 35 a schematic perspective illustration of a third embodiment of the connecting means in which a magnet element is provided in the first connecting element for causing a holding element to execute a rotational movement;
[0102] FIG. 36 a schematic perspective illustration corresponding to FIG. 35 in which the non visible edges are additionally drawn-in in broken lines;
[0103] FIG. 37 a schematic side view of the two components which are connected together by means of the third embodiment of the connecting means;
[0104] FIG. 38 a schematic side view of a magnet element and a holding element of the third embodiment of the connecting means depicted in FIGS. 35 to 37 and a drive unit for producing a rotational movement of the magnet element;
[0105] FIG. 39 a schematic plan view from below of the magnet element and the drive unit depicted in FIG. 38 along the line of sight indicated by the direction of the arrow 39 in FIG. 38 ;
[0106] FIG. 40 a schematic perspective illustration of a fourth embodiment of the connecting means in which two pivotal holding elements and a spreading mechanism for separating apart the end regions of the holding elements are provided in the first connecting element;
[0107] FIG. 41 a schematic side view of the fourth embodiment of the connecting means in the unconnected state of the components;
[0108] FIG. 42 a schematic side view corresponding to FIG. 41 wherein the components that are to be connected together are located against one another and the holding elements are in their release position;
[0109] FIG. 43 a schematic side view of the fourth embodiment of the connecting means corresponding to FIG. 42 wherein the holding elements are in the holding position;
[0110] FIG. 44 a schematic side view of the fourth embodiment of the connecting means, of a magnet element of the spreading mechanism and of a drive unit for causing rotation of the magnet element;
[0111] FIG. 45 a schematic plan view of the magnet element and the drive unit depicted in FIG. 44 along the line of sight indicated by the direction of the arrow 45 in FIG. 44 ;
[0112] FIG. 46 a schematic perspective illustration of two components that are to be connected together whilst they are in the unconnected state, wherein each of the components comprises a respective groove having a base section in the form of a section of a regular cylinder, without undercut sections;
[0113] FIG. 47 a schematic perspective illustration corresponding to FIG. 46 in which the non visible edges are additionally drawn-in in broken lines;
[0114] FIG. 48 a schematic perspective illustration of a fifth embodiment of the connecting means in which the first connecting element comprises a pivotal holding element and both connecting elements comprise anchoring screws;
[0115] FIG. 49 a schematic perspective illustration corresponding to FIG. 48 in which the non visible edges are additionally drawn-in in broken lines;
[0116] FIG. 50 a schematic side view of the two components which are connected together by means of the fifth embodiment of the connecting means;
[0117] FIG. 51 a schematic perspective illustration of the two components that are to be connected together and are depicted in FIG. 46 , together with connecting elements that are inserted into the grooves in the components;
[0118] FIG. 52 a schematic perspective illustration corresponding to FIG. 51 in which the non visible edges are additionally drawn-in in broken lines;
[0119] FIG. 53 a schematic side view of a sixth embodiment of the connecting means in which two pivotal holding elements and a spreading mechanism for separating apart the end regions of the holding elements are provided in the first connecting element and both connecting elements comprise anchoring screws;
[0120] FIG. 54 a schematic side view of the sixth embodiment of the connecting means corresponding to FIG. 53 wherein the two components are fitted together and the holding elements are in their release position; and
[0121] FIG. 55 a schematic side view corresponding to FIG. 54 wherein the holding elements are in the holding position.
[0122] Similar or functionally equivalent elements are designated by the same reference symbols in each of the Figures.
DETAILED DESCRIPTION OF THE INVENTION
[0123] A first embodiment of a connecting means which is illustrated in FIGS. 1 to 9 and bears the general reference 100 is explained in the following using the example of the connection of a first substantially plate-like component 102 to a second likewise substantially plate-like component 104 (see FIGS. 1 to 4 ).
[0124] The two components 102 and 104 consist for example of wood or plywood, but could consist of any other type of material, for example, of a metallic material or a synthetic material (for example plexiglass). Furthermore, provision may be made for the first component 102 and the second component 104 to consist of materials differing from each other.
[0125] In the connected state of the two components 102 and 104 which is illustrated in FIG. 7 , a contact area 106 forming a narrow side of the first component 102 abuts a contact area 108 of the second component 104 which forms a major face of the plate-like second component 104 .
[0126] A respective groove 110 , which is formed in the relevant component 102 and 104 and comprises a base section 112 in the form of a segment of a regular cylinder or a section of a regular cylinder and two undercut sections 114 extending away from the base section 112 in the thickness direction 116 , opens out into each of the contact areas 106 , 108 .
[0127] The radius of curvature of the base section 112 is larger than the groove depth T (see FIG. 4 ), so that the arched groove base surface 118 intersects the respective contact area 106 , 108 at an acute angle.
[0128] The base section 112 of the groove 110 has a width B in the thickness direction 116 of approximately 8 mm for example.
[0129] Each of the undercut sections 114 of the groove 110 is bounded on the side thereof remote from the respective contact area 106 and 108 by a base surface 120 which is flush with the groove base surface 118 and is in the form of a section of the surface of a regular cylinder and has the same radius of curvature as the groove base surface 118 of the base section 112 .
[0130] In the direction toward the contact area 106 or 108 , each undercut section 114 is bounded by an undercut surface 122 which is likewise in the form of a section of the surface of a regular cylinder and is formed such as to be concentric with the base surface 120 and has a smaller radius of curvature.
[0131] In the lateral direction, each of the undercut sections 114 is bounded by a lateral boundary surface 124 running perpendicularly relative to the respective contact area 106 and 108 .
[0132] The width b i.e. the extent thereof in the thickness direction 116 , for each of the undercut sections 114 amounts to approximately 1 mm for example.
[0133] The height h, i.e. the distance between the base surface 120 and the undercut surface 122 , for each of the undercut sections 114 amounts to approximately 2 mm for example.
[0134] The base section 112 of each groove 110 is bounded by lateral boundary walls 126 which run substantially perpendicularly relative to the respective contact area 106 or 108 and are spaced from each other by the groove width B.
[0135] As can be seen from FIG. 3 for example, a substantially cylindrical access boring 128 opens out into the groove 110 of the first component 102 , said boring running perpendicularly relative to one of the lateral boundary walls 126 and the other end thereof opening out at a major face 129 of the plate-like first component 102 , this thereby enabling access to the base section 112 of the groove 110 to be made from the exterior of the first component 102 .
[0136] In order to form the previously described grooves 110 in the components 102 and 104 , the groove cutting device 130 schematically illustrated in FIGS. 10 and 11 can be used for example.
[0137] This groove cutting device 130 comprises an electrically insulated housing 132 which has a substantially flat lower bearing surface 134 and, oriented at right-angles thereto, a substantially flat front bearing surface 136 .
[0138] The front bearing surface 136 comprises a passage slot 138 through which a section of a milling disk 140 can pass, said disk being held such that it can rotate about a vertical rotational axis 142 in the interior of the housing 132 and it is caused to make such a rotational movement about the rotational axis 142 by means of an electrical drive motor 144 .
[0139] The milling disk 140 comprises radially projecting milling teeth 146 around its periphery for milling the base section 112 of a groove 110 and annular groove teeth 148 which project in the axial direction and serve for milling the undercut sections 114 .
[0140] The drive motor 144 and the milling disk 140 attached thereto can be raised or lowered automatically along the axial direction 151 of the milling disk 140 by means of a displacement device 150 . The displacement device 150 and the drive motor 144 are accommodated in a drive unit 152 of the groove cutting device 130 which is displaceable relative to the housing 132 , by means of a handle 154 arranged thereon, in a displacement direction 156 running radially relative to the rotational axis 142 of the milling disk 140 and perpendicularly relative to the front stop surface 136 .
[0141] The displacement device 150 for the axial movement of the milling disk 140 can be implemented as a normal electric motor and associated transmission or as a stepping motor.
[0142] The necessary energy for the displacement movement can be produced by means of a mains power pack or a generator which is coupled to the main drive spindle of the groove cutting device 130 .
[0143] In particular, the generator can be implemented as an electrically controllable eddy-current coupling wherein an arbitrarily adjustable torque can be transferred to a reciprocating means which can mechanically convert this torque into a reciprocating movement of the milling disk 140 without the use of an additional motor, for example, by means of a crank drive arrangement or with the help of an adjustable swash plate.
[0144] The stroke path, over which the milling disk 140 is raised or lowered in the axial direction 151 by the actuation of the displacement device 150 , is manually selectable by means of a selector switch or by means of a CNC control system.
[0145] The manner of functioning of the previously described groove cutting device 130 is as follows:
[0146] The front bearing surface 136 of the groove cutting device 130 is placed on the contact area 106 of that component (for example the first component 102 ) in which the groove 110 is intended to be formed.
[0147] Subsequently, the milling disk 140 is set into rotational movement and is pushed out of the housing 132 against the component 102 that is to be worked upon by means of the handle 154 so that the milling disk 140 mills out from the component 102 a base section 112 which is in the form of a section of a regular cylinder having an increasing groove depth (see FIG. 12 ).
[0148] When the desired groove depth T is reached, a displacement process of the milling disk 140 is initiated by means of the displacement device 150 , whereupon the milling disk 140 is moved upwardly in the axial direction 151 by the desired width b of the undercut section 114 and the upper undercut section 114 of the groove 110 is then milled by means of the annular groove teeth 148 (see FIG. 13 ).
[0149] Subsequently, the milling disk 140 is moved downwardly in the opposite direction back into the initial position and then continues to be moved further downwardly by the desired width b of the undercut section 114 , whereby the annular groove teeth 148 of the milling disk 140 now mill the lower undercut section 114 (see FIG. 14 ).
[0150] When the lower undercut section 114 has also been milled, the milling disk 140 is moved back upwardly along the axial direction 151 into its initial position and is withdrawn from the finished groove 110 in the direction of displacement 156 by pulling back the handle 154 (see FIG. 15 ).
[0151] Initiation of the displacement process can be effected by means of a manually operated switch on the groove cutting device 130 for example.
[0152] As an alternative thereto, provision may also be made for the groove cutting device 130 to comprise a depth probe which automatically initiates the displacement process of the displacement device 150 when the desired groove depth T is reached i.e. when the milling disk 140 has moved out from the housing 132 by a predetermined distance.
[0153] Once the displacement process has been initiated, the further time sequence of the displacement process, i.e. the movement of the milling disk 140 upwardly by the distance b, the subsequent movement of the milling disk 140 downwardly by the distance 2 b and the concluding movement of the milling disk 140 upwardly by the distance b into the starting position is effected automatically by appropriately controlling the displacement device by means of a (not illustrated) control device of the groove cutting device 130 .
[0154] In this way, the groove 110 including the undercut sections 114 can be produced in a simple manner in just a single processing step.
[0155] As an alternative to the groove cutting device 130 illustrated in FIGS. 10 and 11 , the groove cutting device 158 illustrated in FIG. 16 could also be used for the production of the grooves 110 in the components 102 and 104 .
[0156] This groove cutting device 158 comprises an electrical drive unit in an insulated housing 160 and a machining head 162 which is mounted thereon and comprises a T-groove cutter 164 that is rotatable about a rotational axis 166 .
[0157] The T-groove cutter 164 comprises a shank part 168 having a diameter which corresponds to the diameter B of the base section 112 of the groove 110 that is to be milled, and a head part 170 the diameter of which corresponds to the sum, B+ 2 b, of the widths of the base section 112 and the undercut sections 114 .
[0158] Furthermore, the groove cutting device 158 comprises a guidance device 172 for guiding the groove cutting device 158 in a pre-milled guide groove 174 (see FIGS. 17 and 18 ).
[0159] This guidance device 174 comprises a quarter-circular disk-shaped front guide element 174 which is arranged in front of the T-groove cutter 164 in the direction of movement of the groove cutting device 158 during the milling process and the thickness thereof is substantially equal to the width B′ of the pre-milled guide groove 174 .
[0160] Furthermore, the guidance device 172 comprises a substantially quarter-circular disk-shaped rear guide element 178 which is arranged behind the T-groove cutter 164 in the direction of movement of the groove cutting device 158 during the milling process and the thickness thereof corresponds substantially to the width B of the base section 112 of the groove 110 that is to be milled.
[0161] Furthermore, the rear guide element 178 is provided with two guide teeth 180 which are arranged directly behind the head part 170 of the T-groove cutter 164 and which extend respectively upwardly and downwardly in the thickness direction of the rear guide element 178 by the desired width b of the undercut sections 114 of the groove 110 that is to be milled.
[0162] The groove 110 is produced in the contact area 106 of the first component 102 for example using the previously described groove cutting device 158 as follows:
[0163] Firstly, a guide groove 174 in the form of a section of a regular cylinder the groove depth T of which corresponds to the groove depth of the groove 110 that is to be produced and the width B′ of which is smaller than the width B of the base section 112 of the groove 110 that is to be formed is produced by means of a groove cutting device which is known and does not therefore need to be described in detail here (see FIGS. 17 and 18 ).
[0164] In particular, the width B′ of the guide groove 174 may amount to approximately 4 mm for example.
[0165] Subsequently, the guide groove 174 is widened out to form the desired groove 110 with the undercut sections 114 by means of the groove cutting device 158 .
[0166] For this purpose, the front guide element 176 of the guidance device 172 is entered into the guide groove 174 until such time as the outer surface 182 of the front guide element 176 , which is in the form of a section of the surface of a regular cylinder and has the same radius of curvature as the guide groove 174 , abuts flush against the groove base surface of the guide groove 174 and the T-groove cutter 164 is still located in front of the contact area 106 .
[0167] Subsequently, the groove cutting device 158 is pivoted in such a way that the outer surface 182 of the front guide element 176 slides along the arc-shaped curved groove base surface of the guide groove 174 and the T-groove cutter 164 thereby enters into the first component 102 and mills both the widened base section 112 of the groove 110 as well as its undercut sections 114 (see FIGS. 19 and 20 ).
[0168] Thereby, the guide teeth 180 arranged on the rear guide element 178 run in the undercut sections 114 of the groove 110 that were produced by the T-groove cutter 164 and therefore provide additional guidance for the groove cutting device 158 .
[0169] The groove cutting device 158 continues to be pivoted along the guide groove 174 until such time as the T-groove cutter 164 emerges from the component 102 at the end of the guide groove 174 opposite the starting point and the guide teeth 180 are also no longer in engagement with the undercut sections 114 of the groove 110 that has been produced.
[0170] The groove cutting device 158 can now be withdrawn from the component 102 , and the groove 110 including its undercut sections 114 is finished (see FIGS. 21 and 22 ).
[0171] After the grooves 110 in the first component 102 and the second component 104 have been produced, the access boring 128 connecting the one major face 129 to the base section 112 of the groove 110 is then produced in the first component 102 .
[0172] The connecting means 100 which connects the two components 102 and 104 together comprises a first connecting element 184 for insertion into the groove in the first component 102 and a second connecting element 186 for insertion into the groove 110 in the second component 104 , such as are illustrated in FIGS. 5 to 7 .
[0173] The first connecting element 184 comprises a housing 188 that is substantially in the form of a section of a regular cylinder and includes an arc-shaped curved bearing surface 190 which is in the form of an arc of a circle in a longitudinal section taken in the longitudinal direction 192 of the connecting element 184 , and also a flat bearing surface 194 located opposite the curved bearing surface 190 as well as two lateral side faces 198 running substantially parallel to the direction of connection 196 .
[0174] A respective arc-shaped curved holding projection 200 protrudes from the lower edge of the side faces 198 in a thickness direction 202 which is perpendicular to the longitudinal direction 192 and the direction of connection 196 .
[0175] Each holding projection 200 is bounded in the direction towards the bearing surface 194 by an arc-shaped curved supporting surface 204 which is in the form of an arc of a circle in a longitudinal section taken along the longitudinal direction 192
[0176] Each holding projection 200 is bounded on the side remote from the bearing surface 194 by a likewise arc-shaped curved bearing surface which is in the form of an arc of a circle in a longitudinal section taken along the longitudinal direction 192 and adjoins the bearing surface 190 of the housing 188 in flush manner.
[0177] The supporting surface 204 and the bearing surface 206 of each holding projection 200 are connected to one another by a side face 208 which runs substantially parallel to the longitudinal direction 192 and is parallel with the direction of connection 196 .
[0178] The profile of each holding projection 200 substantially corresponds to the profile of the respectively associated undercut section 114 of the groove 110 , and the curvature of the holding projection 200 corresponds to the curvature of the associated undercut section 114 so that the holding projections 200 of the first connecting element 184 are insertible into the undercut sections 114 of the groove 110 and are adapted to be displaced therein in sliding manner.
[0179] Furthermore, the first connecting element 184 comprises a seating chamber 210 that is surrounded by the housing 188 for accommodating a holding element 212 which can emerge from the seating chamber 210 through a mouth 214 at which the seating chamber 210 opens out into the bearing surface 194 of the first connecting element 184 .
[0180] The seating chamber 210 can extend on the side thereof remote from its bearing surface 194 into the curved bearing surface 190 .
[0181] The holding element 212 comprises a plate-like base body 216 which, at one end, is provided with ring-like elevated portions 218 that surround a seating opening 220 having a polygonal cross section which is aligned with a substantially circular passage opening 222 in one of the side faces 198 of the housing 188 .
[0182] The ring-like elevated portions 218 are supported on abutments which are arranged in the seating chamber 210 so that the holding element 212 is held on the housing 188 such as to be rotatable about the central axis 224 of the seating opening 220 .
[0183] The free end of the holding element 212 remote from the ring-like elevated portions 218 is provided with arc-shaped projections 226 which project from the base body 216 on both sides thereof in the thickness direction 202 .
[0184] Furthermore, on both sides of the mouth 214 of the seating chamber 210 , the first connecting element 184 comprises a respective insertible projection 228 in the form of a substantially parallelepipedal dowel pin 230 which extends in the direction of the connection 196 commencing from the bearing surface 194 and tapers towards the end thereof remote from the bearing surface 194 in order to facilitate the insertion thereof into a respective seating pocket 232 of the second connecting element 186 that is complementary to the dowel pin 230 .
[0185] The insertible projections 228 of the first connecting element 184 fit very precisely into the seating pockets 232 of the second connecting element 186 in the thickness direction 202 so that the insertible projections 228 can accommodate the shear stresses of the connection between the components 102 and 104 in the thickness direction 202 , and, additional dowel pins, such as are necessary in the case of most other connecting means, can be dispensed with.
[0186] In the longitudinal direction 192 however, the seating pockets 232 have a greater extent than the insertible projections 228 so that the first connecting element 184 and the second connecting element 186 can be mutually displaced in the longitudinal direction 192 in order to enable the tolerances in the connection between the components 102 and 104 to be compensated for in this way.
[0187] The second connecting element 186 likewise comprises a housing 234 which is substantially in the form of a section of a regular cylinder and has an arc-shaped curved bearing surface 190 that is in the form of an arc of a circle in a longitudinal section taken along the longitudinal direction 192 of the connecting element 186 , a flat bearing surface 194 located opposite the curved bearing surface 190 , side faces 198 and holding projections 200 which protrude from the side faces 198 in the thickness direction 202 , said projections having a curved supporting surface 204 directed towards the bearing surface 194 , a curved bearing surface 206 that is flush with the bearing surface 190 and a side face 208 .
[0188] Furthermore, as can best be seen from FIG. 6 , apart from the seating pockets 232 for the insertible projections 228 of the first connecting element 184 , the housing 234 of the second connecting element 186 also comprises a receiving chamber 236 which is arranged centrally between the seating pockets 233 and opens out into a mouth 238 in the bearing surface 194 and can extend into the bearing surface 190 on the opposite side.
[0189] Protruding into the interior of the receiving chamber 236 from both sides of the mouth 238 , there is a respective restraining projection 240 which is in the form of a section of a regular cylinder and has an arc-shaped curved restraining surface 242 in the thickness direction 202 so as to leave a gap between the two restraining projections 240 the width of which is slightly greater than the thickness of the base body 216 of the holding element 212 of the first connecting element 184 .
[0190] For the purposes of establishing the releasable connection between the first component 102 and the second component 104 by means of the connecting means 100 consisting of the first connecting element 184 and the second connecting element 186 , one proceeds as follows:
[0191] Firstly, as is illustrated in FIG. 23 , the first connecting element 184 is pushed into the groove 110 in the first component 102 in such a way that the holding projections 200 of the first connecting element 184 engage in the undercut sections 114 of the groove 110 and the passage opening 222 in the side face 198 of the housing 188 aligns with the access boring 128 in the first component 102 (see FIG. 24 ).
[0192] In like manner, the second connecting element 186 is pushed into the groove 110 in the second component 104 in such a way that its holding projections 200 engage in the undercut sections 114 of the groove 110 and the housing 234 of the second connecting element 186 is accommodated substantially entirely in the groove 110 (see FIG. 24 ).
[0193] The holding element 212 of the first connecting element 184 is then pivoted completely into the seating chamber 210 of the first connecting element 184 (see FIG. 24 ).
[0194] In this release position of the holding element 212 , the two components 102 and 104 can be moved against each other until their contact areas 106 and 108 as well as the bearing surfaces 194 of the connecting elements 184 and 186 fit together in flush manner and the insertible projections 228 of the first connecting element 184 engage in the seating pockets 232 of the second connecting element 186 (see FIG. 25 ).
[0195] Then, the actuating end of a cranked polygonal key 244 is introduced through the access boring 128 in the first component 102 and the passage opening 222 in the housing 188 of the first connecting element 184 into the seating opening 220 of the holding element 212 and brought into engagement with the latter (see FIG. 25 ).
[0196] Subsequently, the holding element 212 is pivoted out from the seating chamber 210 of the first connecting element 184 by means of the polygonal key 242 so that the arc-shaped projections 226 of the holding element 212 enter the receiving chamber 236 of the second connecting element 186 through the mouth 238 and thereby engage behind the restraining projections 240 .
[0197] The curvature of the arc-shaped projections 226 of the holding element 212 on the one hand and the curvature of the restraining surfaces 242 of the restraining projections 240 are matched to one another in such a way that the two connecting elements 184 and 186 are pulled against each other to an increasing extent in the direction of the connection 196 during the process of pivoting the holding element 212 into the receiving chamber 236 and there results as large a contact area as possible between the restraining surfaces 242 and the arc-shaped projections 226 of the holding element 212 .
[0198] In consequence, compression stress points in the contact areas between the restraining projections 240 and the arc-shaped projections 226 of the holding element 212 are prevented and the strength of the material from which the holding element 212 and the housing 234 of the second connecting element 186 are made is used as uniformly as possible.
[0199] The holding element 212 and the housings 188 and 234 of the respective connecting elements 184 and 186 can therefore be made, in particular, of an injection moulded synthetic material.
[0200] When the connection between the connecting elements 184 and 186 is loaded in the direction of connection 196 , the holding element 212 experiences substantially only tension and thrust forces, but only to a negligibly small degree, bending moments.
[0201] The seating chamber 210 of the first connecting element 184 , the receiving chamber 236 of the second connecting element 186 and the outer contours of the connecting elements 184 and 186 are formed in such a way that they can be manufactured in one-piece manner.
[0202] The holding element 212 can be pushed into the seating chamber 210 through the mouth of the seating chamber 210 onto the bearing surface 190 of the first connecting element 184 so that the housing 188 of the first connecting element 184 does not need to be separable.
[0203] Consequently, one can dispense with constructing the housing 188 of the first connecting element 184 in the form of two half-shells, this thereby increasing the rigidity of the first connecting element 184 .
[0204] Since the curved bearing surfaces 190 of the connecting elements 184 and 186 have the same radius of curvature as the groove base surfaces 118 of the grooves 110 upon which the bearing surfaces 190 can slide and abut, and since the holding projections 200 of the connecting elements 184 and 186 in the form of an arc of a circle can be displaced tangentially in the respectively associated undercut sections 114 of the grooves 110 using just a small amount of force and hence the connecting elements 184 and 186 still have a certain degree of freedom of movement when establishing the connection, it is still possible to make corrections with respect to the mutual positioning of the connecting elements 184 and 186 during the process of connecting the components 102 and 104 .
[0205] This significantly reduces the need for precision in regard to the location of the grooves 110 in the components 102 and 104 and thus leads to it being considerably easier for the user to use.
[0206] When the holding element 212 is moved from the release position illustrated in FIG. 25 into the holding position illustrated in FIG. 26 , then, due to the tensile forces which act on the connecting elements 184 and 186 in the direction of connection 196 , such a large amount of static friction will be produced between the supporting surfaces 204 of the holding projections 200 on the one hand and the undercut surfaces 122 of the undercut sections 114 of the grooves 110 which are thereby in contact therewith on the other that the previously described remaining degree of freedom of movement is neutralised and an extremely firm connection between the components 102 and 104 is established.
[0207] As a result of the support for the holding projections 200 on the undercut surfaces 122 of the undercut sections 114 of the grooves 110 in the components 102 and 104 , the connecting elements 184 and 186 are thus securely anchored in the respectively associated component 102 and 104 .
[0208] In the holding position illustrated in FIGS. 7 and 26 , the holding element 212 in cooperation with the restraining projections 240 prevents a relative movement of the first connecting element 184 and the second connecting element 186 along the direction of the connection 196 .
[0209] In order to then release the first component 102 and the second component 104 from each other, it is only necessary to again insert a polygonal key 244 through the access boring 128 in the first component 102 so as to engage with the seating opening 220 in the holding element 212 and then to move the holding element 212 by pivoting it in the opposite direction from the holding position into the release position illustrated in FIG. 25 in which the arc-shaped projections 226 of the holding element 212 no longer engage behind the restraining projections 240 of the second connecting element 186 so that the connecting elements 184 and 186 can easily be moved apart along the direction of connection 196 .
[0210] As can be seen from FIGS. 27 to 31 , the profiles of the holding projections 200 do not by any means always have to be formed such that they are exactly rectangular, as is illustrated in FIG. 28 .
[0211] Rathermore, provision could also be made for the profile of the holding projections 200 to be trapezoidal, this then tapering with increasing spacing from the side faces 198 of the respective housing 188 and 234 , as is illustrated in FIG. 29 .
[0212] As an alternative thereto, provision may also be made for the profile of the holding projections 200 to taper with decreasing spacing from the respectively associated side face 198 , as is illustrated in FIG. 30 .
[0213] Furthermore, provision may be made for the profile of the holding projections 200 to have an outer contour which is curved at least in sections thereof, for example a semicircular outer contour, such as is illustrated in FIG. 31 .
[0214] A second embodiment of a connecting means 100 which is illustrated in FIGS. 32 to 34 differs from the previously described first embodiment in that the holding element 212 in the second embodiment is formed as a threaded element 246 having an external thread 248 which is brought into engagement with an internal thread 250 of a restraining element 252 of the second connecting element 186 for the purposes of connecting the two components 102 , 104 .
[0215] As can best be seen from FIG. 33 , the threaded element 246 of the first connecting element 184 comprises outside the external thread 248 a cylindrical head part 254 having a central seating 256 for an actuating section of a (not illustrated) actuating element such as a polygonal key or a screwdriver for example, wherein the seating 256 has a polygonal cross section complementary to the cross section of the actuating section.
[0216] Between the head part 254 and the external thread 248 of the threaded element 246 , there is arranged a cylindrical shank part 258 which has a smaller diameter than the head part 254 .
[0217] The head part 254 and the shank part 258 are arranged in a stepped seating chamber 260 of the housing 188 of the first connecting element 184 which has a lower chamber section 262 of greater diameter and an upper chamber section 264 of lesser diameter, wherein the two chamber sections 262 , 264 merge into one another at a shoulder 266 on which the head part 254 of the threaded element 246 is supported.
[0218] The upper chamber section 264 extends upwardly along the direction of connection 196 and opens out into the bearing surface 194 of the first connecting element 184 .
[0219] The threaded element 246 serving as a holding element 212 is thus arranged on the first connecting element 184 such that it is rotatable about an axis of rotation 268 that is oriented parallel to the direction of connection 196 .
[0220] The restraining element 252 of the second connecting element 186 has a parallelepipedal outer contour and is held such that it is displaceable in the longitudinal direction 192 in non rotatable manner in a likewise parallelepipedal seating chamber 270 in the housing 234 of the second connecting element 186 .
[0221] The seating chamber 270 is pierced by an access channel 272 which extends along the direction of the connection 196 from the bearing surface 194 of the second connecting element 186 through the seating chamber 270 up to the curved bearing surface 190 of the second connecting element 186 and it has an elongate and in particular, oval cross section.
[0222] For the purposes of establishing the connection between the first component 102 and the second component 104 , the first connecting element 184 and the second connecting element 186 of the second embodiment of the connecting means 100 are inserted into the respective grooves 110 of the first component 102 and the second component 104 .
[0223] Then, the second component 104 with the second connecting element 186 is placed on the first component 102 with the first connecting element 184 in such a way that the external thread 248 of the threaded element 246 extends through the access channel 272 of the second connecting element 186 into the seating chamber 250 and comes into engagement with the internal thread 270 of the restraining element 252 .
[0224] Subsequently, the threaded element 246 is set into rotation about the rotational axis 268 by means of the (not illustrated) actuating element (a screwdriver for example) which engages in the seating 256 in the head part 254 of the threaded element 246 through an access boring in the first component 102 so that the external thread 248 of the threaded element 246 is screwed into the internal thread 250 of the restraining element 252 and hence the second connecting element 186 is pulled against the first connecting element 184 until the state illustrated in FIG. 34 is reached, in which the bearing surfaces 194 of the two connecting elements 184 , 186 fit flushly together and the external thread 248 extends beyond the seating chamber 270 into the section of the access channel 272 lying between the seating chamber 270 and the bearing surface 190 of the second connecting element 186 .
[0225] In order to enable the actuating element to engage in the seating 256 in the head part 254 of the threaded element 246 , the access boring in the first component 102 in the case of this embodiment is aligned coaxially with respect to the axis of rotation 268 of the threaded element 246 and thus parallel to the direction of the connection 196 .
[0226] In this embodiment, the separation of the two components 102 and 104 from each other is effected in that the external thread 248 is unscrewed from the internal thread 250 of the restraining element 252 by rotating the threaded element 246 in the opposite direction by means of the (not illustrated) actuating element until the threaded element 246 is no longer in engagement with the restraining element 252 and the second connecting element 186 can thus be removed from the first connecting element 184 .
[0227] Due to the displaceability of the restraining element 252 in the longitudinal direction 192 and as a result of the elongate cross section of the access channel 272 , it is possible to have a certain amount of relative movement between the threaded element 246 and the housing 234 of the second connecting element 186 when establishing the connection between the first component 102 and the second component 104 so that tolerances in the positioning of the grooves 110 in the components 102 , 104 can thereby be compensated for.
[0228] The second embodiment of the connecting means 100 illustrated in FIGS. 32 to 34 does not comprise insertible projections on the first connecting element 184 , but, in like manner to the first embodiment, it does comprise holding projections 200 on the connecting elements 184 and 186 .
[0229] In all other respects, the second embodiment of the connecting means 100 illustrated in FIGS. 32 to 34 coincides in regards to the construction and manner of functioning thereof with the first embodiment illustrated in FIGS. 1 to 31 , so that to this extent reference is made to the previous description thereof.
[0230] A third embodiment of the connecting means 100 illustrated in FIGS. 35 to 39 differs from the previously described first embodiment in that the housing 188 of the first connecting element 184 comprises a hump-like elevated portion 274 between the two insertible projections 228 , said elevated portion engaging in a complementarily shaped depression 276 in the housing 234 of the second connecting element 186 in the connected state of the components 102 , 104 (see FIG. 37 ).
[0231] A certain amount of play is present in the longitudinal direction 192 between the elevated portion 274 and the depression 276 so that tolerances in the positioning between the grooves 110 and the components 102 , 104 can be compensated for.
[0232] In this embodiment, the holding element 212 of the first connecting element 184 is formed as a threaded element 278 which comprises a hollow cylindrical socket section 280 having an internal thread 282 and a shaft section 284 that extends downwardly from the socket section 280 along the direction of connection 196 and has a smaller diameter than the socket section 280 as well as a driven element 286 which projects downwardly from the periphery of the socket section 280 in the axial direction (see in particular, FIG. 38 ).
[0233] As can best be seen from FIG. 36 , the threaded element 278 is arranged in a stepped seating chamber 288 of the housing 188 of the first connecting element 184 , said chamber comprising a lower chamber section 290 of greater diameter and an upper chamber section 292 of lesser diameter wherein these chambers merge into one another at a shoulder 294 .
[0234] The threaded element 278 is arranged in the seating chamber 288 such as to be rotatable about an axis of rotation 296 oriented parallel to the direction of connection 196 .
[0235] Furthermore, in order to be able to produce a rotational movement of the threaded element 278 about the axis of rotation 296 , there is provided in the lower chamber section 290 of the seating chamber 288 a hollow cylindrical magnet element 298 which is aligned coaxially with respect to the threaded element 278 and is pushed partially onto the shaft section 284 of the threaded element 278 and it is provided at the end face thereof facing the socket section 280 with an axially projecting driver element 300 (see in particular, FIG. 38 ).
[0236] The magnet element 298 consists of a permanent magnet material which is magnetized substantially perpendicularly to its longitudinal axis and thus perpendicularly to the axis of rotation 296 (so-called diametrical magnetization).
[0237] The diametrically magnetized magnet element 298 , which is mounted on the shaft section 284 of the threaded element 278 such as to be rotatable about the axis of rotation 268 , can be caused to make an oscillatory rotational movement about the axis of rotation 296 by means of a time varying external magnetic drive field that acts on the magnet element 298 from outside the connecting means 100 , said movement producing a directed rotational movement of the threaded element 278 about the axis of rotation 296 due to the interaction between the driver element 300 of the magnet element 298 and the driven element 286 of the threaded element 278 .
[0238] For this purpose, there is used a drive unit 302 which is schematically illustrated in FIGS. 38 and 39 , said drive unit comprising a housing 304 , which consists of a synthetic material for example, an electric motor 306 having a drive shaft 308 arranged in the housing 304 , and a drive magnet 310 connected in mutually non-rotatable manner to the drive shaft 308 .
[0239] The drive magnet 310 is formed as a cylindrical high power permanent magnet which is magnetized substantially perpendicularly to the longitudinal direction 312 of the drive shaft 308 (so-called diametrical magnetization).
[0240] For the purposes of establishing a rotational movement of the threaded element 278 , one now proceeds as follows:
[0241] The drive unit 302 is moved relative to the first connecting element 184 into a position in which the longitudinal direction 312 of the drive shaft 308 of the drive unit 302 and the axis of rotation 296 of the threaded element 278 are oriented parallel to each other and the spacing between the drive magnet 310 and the magnet element 298 is as small as possible in order to obtain as strong a mutual interaction of the magnets as possible. The location of the drive unit 302 and that of the magnet element 298 in this position are schematically illustrated in FIGS. 38 and 39 .
[0242] If the electric motor 306 of the drive unit 302 is now operated in such a way that the drive shaft 308 and thus the drive magnet 310 rotate in the clockwise direction for example (when viewed along a line of sight indicated by the arrow 39 in FIG. 38 ), then the north pole (N) and the south pole (S) of the drive magnet 310 thereby rotate in the clockwise direction due to the diametrical magnetization of the drive magnet 310 , as is to be seen in the schematic illustration of FIG. 39 .
[0243] The rotational movement of the drive magnet 310 thus produces a rotating and hence time varying magnetic drive field.
[0244] In order to enable this magnetic drive field to penetrate into the interior of the first connecting element 184 and interact with the magnet element 298 , the housing 188 of the first connecting element 184 consists of a non-ferromagnetic material, for example, it consists of a synthetic material.
[0245] Since unlike poles of the magnet element 298 and the drive magnet 310 attract one another and like poles of these elements repel each other, the magnet element 298 in the seating chamber 288 rotates in the opposite direction of rotation due to the interaction with the drive magnet 310 , i.e. in the counter clockwise direction (in the line of sight indicated by the arrow 39 in FIG. 38 ).
[0246] Due to this rotational movement, the driver element 300 of the magnet element 298 comes into contact with the driven element 286 of the threaded element 278 so that the threaded element 278 is forced by the magnet element 298 into making a rotational movement about the axis of rotation 296 in the same direction of rotation as that of the magnet element 298 .
[0247] The magnet element 298 and the threaded element 278 carried along thereby follow the rotational movement of the drive magnet 310 until such time as the resistance acting on the threaded element 278 (which, for example, is exerted due to the fact that the internal thread 282 of the threaded element 278 is rotated on a complementary external thread 314 of a restraining element 316 provided on the second connecting element 186 ) becomes so large that the torque being transferred by the rotary magnetic field produced by the drive magnet 310 is no longer sufficient to continue to rotate the threaded element 278 . When such a blockage point is reached, the threaded element 278 and the magnet element 298 then remain in the position they have reached, whilst the drive magnet 310 continues to rotate.
[0248] After the drive magnet 310 has continued to rotate through approximately 180° so that the like poles of the drive magnet 310 and the magnet element 298 are then located directly opposite each other, the magnet element 298 is again caused to move in a flip-over process, namely, in a direction of rotation having the same sense as the direction of rotation of the drive magnet 310 until the unlike poles of the drive magnet 310 and the magnet element 298 are located directly opposite each other once again.
[0249] Once this state is reached, the direction of rotation of the magnet element 298 then reverses again, and the magnet element 298 again rotates in the opposite sense to the drive magnet 310 , as occurred in the phase prior to the blockage of the threaded element 278 .
[0250] The magnet element 298 is now accelerated through approximately half a revolution by the rotating magnetic field of the drive magnet 310 until the driver element 300 again strikes the driven element 286 of the threaded element 278 and the impulse of the magnet element 298 is suddenly transferred to the driven element 286 and thus to the threaded element 278 . Due to this large impulse transmission, the threaded element 278 can release itself from its blockage position and continue to rotate through a certain angle into a position in which a renewed blockage of the threaded element 278 occurs. The magnet element 298 thus stops again in this new blockage position without being able to follow the drive magnet 310 any further until the like poles of the magnet element 298 and the drive magnet 310 are located directly opposite each other again and a renewed flip-over process of the magnet element 298 enables renewed reception of an impulse to occur.
[0251] The threaded element 278 continues to rotate from blockage position to blockage position in this periodically repeating manner. The repeated receipt of momentum and striking of the driver element 300 against the driven element 286 produce an impact hammer action which powerfully accelerates the rotational movement of the threaded element 278 about the axis of rotation 296 against a resistance.
[0252] Further details for the process of creating a rotational movement of the threaded element 278 by means of an external drive magnet 310 can be derived from DE 198 07 663 A1 to which reference in this connection is made and which is hereby incorporated as a component part of the present description.
[0253] Due to the rotational movement of the threaded element 278 that is produced in such a manner, the internal thread 282 of the threaded element 278 can be screwed to the external thread 314 of the restraining element 316 provided on the second connecting element 186 or it can be released from the external thread 314 (upon reversal of the direction of rotation of the drive magnet 310 ).
[0254] In this embodiment, the restraining element 316 comprises a square head 318 which is fed with a certain amount of play into a parallelepipedal seating chamber 320 within the housing 234 of the second connecting element 186 and thus prevented from rotating about the direction of the connection 196 .
[0255] From the lower surface of the square head 318 , the external thread 314 of the restraining element 316 extends through an access channel 322 running parallel to the direction of the connection 196 into the depression 276 of the second connecting element 186 so that this external thread 314 is then located opposite the internal thread 282 of the threaded element 278 on the first connecting element 184 (see FIGS. 35 and 36 ).
[0256] Furthermore, as can be seen from FIG. 37 , there is provided in the seating chamber 320 a compression spring 324 which biases the restraining element 316 against the first connecting element 184 in the direction of connection 196 .
[0257] For the purposes of establishing the connection between the first component 102 and the second component 104 by means of the third embodiment of the connecting means 100 , one proceeds as follows:
[0258] After the first connecting element 184 and the second connecting element 186 have been inserted into the respective grooves 110 of the first component 102 and the second component 104 , the second component 104 with the second connecting element 186 is moved against the first component 102 with the first connecting element 184 in such a way that the internal thread 282 of the threaded element 278 comes into engagement with the external thread 314 of the restraining element 316 .
[0259] The insertible projections 228 also penetrate the seating pockets 232 of the second connecting element 186 that are complementary thereto and the hump-like raised portion 274 of the first connecting element 184 enters the depression 276 in the second connecting element 186 that is complementary thereto.
[0260] Subsequently, in the manner already described hereinabove, the threaded element 278 is caused to effect a rotational movement about the axis of rotation 296 by means of the drive unit 302 in such a manner that the socket section 280 of the threaded element 278 having the internal thread 282 and the restraining element 316 having the external thread 314 are screwed together so that the second connecting element 186 is pulled against the first connecting element 184 and the connection between the components 102 and 104 is established.
[0261] For the purposes of releasing the connection between the components 102 and 104 , the screwed connection between the threaded element 278 and the restraining element 316 is undone by using the drive unit 302 with the opposite direction of rotation of the drive magnet 310 .
[0262] In all other respects, the third embodiment of the connecting means 100 illustrated in FIGS. 35 to 39 coincides in regards to the construction and manner of functioning thereof with the first embodiment illustrated in FIGS. 1 to 31 , so that to this extent reference is made to the previous description thereof.
[0263] A fourth embodiment of the connecting means 100 illustrated in FIGS. 40 to 45 differs from the embodiment illustrated in FIGS. 1 to 31 in that instead of having two insertible projections 228 on the first connecting element 184 , there is provided just a single central insertible projection 326 which engages in a seating pocket 328 of the second connecting element 186 that is complementary thereto in the connected state of the components 102 , 104 .
[0264] Furthermore, in this embodiment, the first connecting element 184 does not comprise just a single holding element 212 , but rather, it comprise two holding elements 212 which are held such as to be pivotal on the housing 188 of the first connecting element 184 , these holding elements being in the form of hinged levers 330 of which one is arranged on each side of the central insertible projection 326 .
[0265] The inner end regions 332 of the hinged levers 330 which are mounted on bearing projections 335 such as to be pivotal about pivotal axes 333 engage in a seating chamber 334 within the housing 188 and are held at a distance from one another by means of a spreading mechanism 336 .
[0266] The spreading mechanism 336 itself comprises a first spreading element 338 having a square head 340 , a shank section 342 which extends from the square head 340 in the longitudinal direction 192 and a threaded section 344 having an external thread which adjoins the shank section 342 .
[0267] Furthermore, the spreading mechanism 336 comprises a second spreading element 346 having a cylindrical head section 348 and a hollow cylindrical socket section 350 which is provided with an internal thread and extends from the head section 348 in the longitudinal direction 192 such as to be coaxial with the shank section 342 of the first spreading element 338 .
[0268] The internal thread of the socket section 350 of the second spreading element 346 is now in engagement with the external thread of the threaded section 344 of the first spreading element 338 .
[0269] Furthermore, the socket section 350 is provided at the end thereof facing the square head 340 of the first spreading element 338 with a driven element 352 which projects in the radial direction.
[0270] Between the square head 340 of the first spreading element 338 and the socket section 350 of the second spreading element 346 , there is a hollow cylindrical magnet element 354 having diametrical magnetization which is arranged on the shank section 342 of the first spreading element 338 such as to be rotatable about the common longitudinal axis 356 of the two spreading elements 338 and 346 .
[0271] At the end face thereof facing the socket section 350 of the second spreading element 346 , the magnet element 354 is provided with a driver element 358 which projects in the axial direction and which can act on the driven element 352 on the socket section 350 .
[0272] Between the square head 340 of the first spreading element 338 and the end face of the magnet element 354 facing said square head, there is arranged a compression spring 360 which biases the magnet element 354 against the socket section 350 of the second spreading element 346 .
[0273] As can best be seen from FIGS. 44 and 45 , the second spreading element 346 of the spreading mechanism 336 is adapted to be driven in like manner to the threaded element 278 of the previously described third embodiment of the connecting means 100 , by means of a drive unit 302 incorporating a rotary drive magnet 310 which interacts with the magnet element 354 , such as to execute a rotational movement about the longitudinal axis 356 relative to the first spreading element 338 which is held in a constant rotational position by its square head 340 .
[0274] To this end as illustrated in FIGS. 44 and 45 , the drive unit 302 is oriented outside the connecting means 100 in such a way that the longitudinal direction 312 of the drive shaft 308 is oriented substantially parallel to the longitudinal axis 356 of the spreading elements 338 , 346 and the spacing between the drive magnet 310 and the magnet element 354 is made as small as possible.
[0275] In the housing 234 of the second connecting element 186 , there are provided two receiving chambers 362 into which the outer end regions 364 of the hinged lever 330 can enter when the bearing surfaces 194 of the connecting elements 184 and 186 abut one another.
[0276] Furthermore, recesses 337 for seating the bearing projections 335 protruding from the housing 188 are provided in the housing 234 .
[0277] At the edges thereof facing the first connecting element 184 , the receiving chambers 362 are bounded in sectional manner by a respective restraining projection 366 which can be engaged behind by the respectively associated hinged lever 330 when the hinged lever 330 concerned is pivoted about its pivotal axis 333 from the release position illustrated in FIG. 42 into the holding position illustrated in FIG. 43 .
[0278] Such a pivotal action can be effected by means of the previously described spreading mechanism 336 .
[0279] In this embodiment, the respective housings 188 and 234 of the first connecting element 184 and the second connecting element 186 are preferably formed in two-piece manner, whereby the two parts fit together along the longitudinal centre plane of the respective housing.
[0280] For the purposes of establishing a connection between the first component 102 and the second component 104 by means of the fourth embodiment of the connecting means 100 , one proceeds as follows:
[0281] The first connecting element 184 and the second connecting element 186 are inserted into the respective groove 110 in the first component 102 and in the second component 104 .
[0282] Thereafter, the second component 104 with the second connecting element 186 is placed on the first component 102 with the first connecting element 184 in such a way that the outer end regions 364 of the hinged lever 330 which is located in the release position enter into the receiving chambers 362 of the second connecting element 186 and the central insertible projection 326 of the first connecting element 184 enters into the seating pocket 328 of the second connecting element 186 .
[0283] Subsequently, the second spreading element 346 is caused to effect a rotational movement about the longitudinal axis 356 by means of the drive unit 302 in such a manner that the head section 348 of the second spreading element 346 is removed from the square head 340 of the first spreading element 338 and hence the overall length of the spreading mechanism 336 increases, whereby the inner end regions 332 of the hinged lever 330 are moved away from each other, the hinged levers 330 are pivoted about their pivotal axes 333 and are thereby moved into the holding position illustrated in FIG. 43 in which the outer end regions 364 of the hinged lever 330 engage behind the respectively associated restraining projections 366 of the second connecting element 186 and abut said projections so that the second connecting element 186 is locked onto the first connecting element 184 and the connecting elements 184 , 186 can no longer be moved apart along the direction of connection 196 .
[0284] In order to release the connection of the components 102 , 104 , the second spreading element 346 is rotated relative to the first spreading element 338 about the longitudinal axis 356 by means of the drive unit 302 in the reverse direction of rotation so that the head section 348 of the second spreading element 346 is moved towards the square head 340 of the first spreading element 338 and the overall length of the spreading mechanism 336 shortens.
[0285] The inner end regions 332 of the hinged lever 330 thereupon no longer lie on the square head 340 of the first spreading element 338 or on the head section 348 of the second spreading element 346 so that the spreading mechanism 336 no longer presents any resistance to a pivotal movement of the hinged levers 330 from the holding position illustrated in FIG. 43 into the release position illustrated in FIG. 42 .
[0286] After this process of unlocking the hinged levers 330 , the second connecting element 186 can then be removed from the first connecting element 184 along the direction of connection 196 .
[0287] In all other respects, the fourth embodiment of the connecting means 100 illustrated in FIGS. 40 to 45 coincides in regards to the construction and manner of functioning thereof with the first embodiment illustrated in FIGS. 1 to 31 , so that to this extent reference is made to the previous description thereof.
[0288] A fifth embodiment of the connecting means 100 which is illustrated in FIGS. 46 to 52 differs from the first embodiment which is illustrated in FIGS. 1 to 31 in that holding projections 200 are not provided on the respective housings 188 , 234 of the first connecting element 184 and the second connecting element 186 .
[0289] Accordingly, the grooves 110 in the first component 102 and in the second component 104 only comprise the central base section 112 , but there are no undercut sections protruding therefrom (see FIGS. 46 and 47 ).
[0290] In order nevertheless to obtain secure retention of the connecting elements 184 , 186 in the respectively associated groove 110 , both of the connecting elements 184 , 186 are respectively provided with two anchoring screws 368 which each comprise a screw head 370 and a screw shank 372 having an external thread which protrudes from said head approximately in the radial direction of the bearing surface 190 .
[0291] Each screw head 370 is accommodated in a screw head seating 374 which extends from the bearing surface 194 of the respective housing in the direction of the bearing surface 190 .
[0292] The bottom of each screw head seating 374 upon which the respectively associated screw head 370 is supported is connected to the bearing surface 190 through an access channel 376 .
[0293] The screw shank 372 of each anchoring screw 368 extends through the respectively associated access channel 376 , wherein the access channel 376 has an enlarged cross section in the longitudinal direction 192 as compared with that of the screw shank 372 so that the orientation of the screw shank 372 relative to the bearing surface 190 can be varied within certain limits in order to be able to compensate for the positional tolerances of the grooves 110 in the respective components 102 and 104 .
[0294] For the purposes of establishing a connection between the first component 102 and the second component 104 by means of the fifth embodiment of the connecting means 100 , the grooves 110 are initially produced in the components 102 and 104 by means of a conventional groove cutting device, which requires neither a displacement device nor a T-groove-milling tool.
[0295] Furthermore, the access boring 128 is produced in the first component 102 .
[0296] Subsequently, the first connecting element 184 is inserted into the groove 110 in the first component 102 and is anchored into the groove base of the first component 102 by screwing-in the anchoring screws 368 .
[0297] In like manner, the second connecting element 186 is inserted into the groove 110 in the second component 104 and is anchored therein by means of the anchoring screws 368 .
[0298] After this process of anchoring the connecting elements 184 , 186 onto the respectively associated component 102 and 104 , the connecting elements 184 and 186 are connected to one another in releasable manner in the same way as that which has been previously explained in connection with the description of the first embodiment of the connecting means 100 .
[0299] In all other respects, the fifth embodiment of the connecting means 100 illustrated in FIGS. 46 to 52 coincides in regards to the construction and manner of functioning thereof with the first embodiment illustrated in FIGS. 1 to 31 , so that to this extent reference is made to the previous description thereof.
[0300] A sixth embodiment of the connecting means 100 which is illustrated in FIGS. 53 to 55 likewise differs from the fourth embodiment which is illustrated in FIGS. 40 to 45 in that two anchoring screws 368 are provided on the respective housings 188 and 234 of the first connecting element 184 and the second connecting element 186 instead of the holding projections 200 in order to anchor the connecting elements 184 , 186 in the respectively associated groove 110 of the first component 102 and the second component 104 .
[0301] In the case of this embodiment too, the grooves 110 in the first component 102 and the second component 104 only comprise the central base section 112 but do not have undercut sections protruding therefrom.
[0302] In regard to the construction of the anchoring screws 368 and the arrangement thereof on the housings 188 , 234 of the first connecting element 184 and the second connecting element 186 , reference is made to the previous description of the fifth embodiment of the connecting means 100 which is illustrated in FIGS. 46 to 52 .
[0303] In all other respects, the sixth embodiment of the connecting means 100 illustrated in FIGS. 53 to 55 coincides in regards to the construction and manner of functioning thereof with the fourth embodiment illustrated in FIGS. 40 to 45 , so that to this extent reference is made to the previous description thereof.
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In order to produce a connecting means for connecting a first component and a second component particularly for connecting furniture parts or machine parts which will enable two components to be connected to one another by means of a reliably releasable connection without giving rise to the danger of damaging the two components during the assembly process wherein the device comprises a first connecting element that it arranged on the first component in the connected state of the components and a second connecting element that is arranged on the second component in the connected state of the components and wherein at least one of the connecting elements comprises a curved bearing surface which is in the form of an arc of a circle in longitudinal section, it is proposed that the first connecting element and the second connecting element be connected to one another in releasable manner in the connected state of the components and that at least the first connecting element should comprise a housing and at least one holding element which is moveable relative to the housing of the first connecting element and which, in a holding position, cooperates with the second connecting element in such a way that a relative movement of the first connecting element and the second connecting element along a direction of connection is prevented, and which, in a release position, permits a relative movement of the first connecting element and the second connecting element along the direction of the connection wherein at least one holding element is movable from the holding position into the release position and/or from the release position into the holding position by an action taken outside the connecting means and wherein the housing ( 188 ) of the first connecting element comprises a curved bearing surface ( 190 ) that is in the form of an arc of a circle in longitudinal section, and a substantially flat bearing surface ( 194 ) which is located opposite the aforesaid bearing surface and is arranged to abut the second connecting element ( 186 ).
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CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part application of co-pending U.S. application Ser. No. 10/681,033, filed Oct. 7, 2003, for “Magnetic Resonance Imaging Screening Method and Apparatus”. This is also a continuation-in-part application of co-pending U.S. application Ser. No. 10/703,147, filed Nov. 5, 2003, for “Security Screening Method and Apparatus”, which is a continuation application of co-pending U.S. application Ser. No. 10/681,033, filed Oct. 7, 2003, for “Magnetic Resonance Imaging Screening Method and Apparatus”. This application relies upon U.S. Provisional Pat. App. No. 60/440,697, filed Jan. 17, 2003, for “Method and Apparatus to Use Magnetic Entryway Detectors for Pre-MRI Screening”.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is in the field of methods and apparatus used to prevent the presence of paramagnetic or ferromagnetic objects in a controlled area.
2. Background Art
It can be desirable to exclude paramagnetic and ferromagnetic objects from a controlled area. For instance, paramagnetic and ferromagnetic objects are highly unsafe near MRI systems, because the strong magnetic gradients caused by MRI magnets exert a strong force on such objects, potentially turning them into dangerous missiles. Several accidents, some fatal, are known to have occurred as the result of someone inadvertently carrying such an object into the MRI room. Current MRI safety practices rely on signage and training to prevent people from taking such objects into the MRI chamber. Paramagnetic and ferromagnetic objects which can be weapons may also be unsafe in other controlled areas, such as schools.
Use of known conventional metal detectors, whether portals or wands, would not be efficient for this purpose. Conventional systems generate an audio-band oscillating or pulsed magnetic field with which they illuminate the subject. The time-varying field induces electrical eddy currents in metallic objects. It is these eddy currents which are detected by the system, to reveal the presence of the metallic objects.
BRIEF SUMMARY OF THE INVENTION
The present invention provides an apparatus and a method for scanning a subject for the presence of an object which is either permanently magnetic or susceptible to being magnetized by an external field. The sensors in this scanning apparatus can be mounted on a portal type frame. This positions the entire sensor array in proximity to a subject. The portal arrangement of the scanner arranges the sensors suitably for positioning every sensor in proximity to the body of a subject, as the subject passes through the portal.
The sensors can detect the magnetic field of the object, whether the object is a permanent magnet or merely susceptible to magnetization. Where an external field induces a magnetic field in the object, the external field may be the Earth's magnetic field, or it may be generated by another source, such as a nearby MRI apparatus or a dedicated source such as one mounted on the frame of the apparatus.
The novel features of this invention, as well as the invention itself, will be best understood from the attached drawings, taken along with the following description, in which similar reference characters refer to similar parts, and in which:
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a schematic showing the horizontal arrangement of sensor arrays in a first portal type embodiment;
FIG. 2 is a schematic of a second portal embodiment;
FIG. 3 is a schematic of a third portal embodiment;
FIG. 4 is a schematic of the arrangement of a permanent magnet source relative to the sensing axis of the sensor;
FIG. 5 is a schematic showing the arrangement of the source field from a permanent magnet, a sensor, and a ferromagnetic object;
FIG. 6 is a schematic showing the magnetic field of the ferromagnetic object shown in FIG. 5 ;
FIG. 7 is a schematic showing the arrangement of a sensor and the source field from two permanent magnets;
FIGS. 8 and 9 show a first embodiment of the excitation coil configuration relative to the portal structure;
FIGS. 10 and 11 show a second embodiment of the excitation coil configuration relative to the portal structure; and
FIGS. 12 and 13 show a third embodiment of the excitation coil configuration relative to the portal structure.
DETAILED DESCRIPTION OF THE INVENTION
The present invention, which applies to both permanently magnetic objects called “hard” ferromagnets and non-permanent magnetically susceptible objects called “soft” ferromagnets, can use magnetometers with good sensitivity at frequencies all the way, or nearly, to DC, i.e., zero frequency. This allows several modes of use:
(1) As a completely passive system, the present invention detects ferromagnetic objects using their permanent magnetization, in the case of “hard” ferromagnets, or the magnetization induced by the Earth's magnetic field, in the case of “soft” ferromagnets.
(2) As a DC magnetic susceptometer, the present invention applies a static DC magnetic field, allowing control and usually enhancement of the magnetization of soft ferromagnets, thus enhancing their detectability.
(3) As an AC magnetic susceptometer, the present invention applies an oscillating AC magnetic field, but at very low frequencies compared to conventional detectors, allowing enhancement of their magnetization. The purpose of AC illumination is to move the signal from DC to a region of lower noise at finite frequency. The AC frequency is preferably chosen to avoid inducing the electrical eddy currents detected by other systems, to suppress the response from non-ferromagnetic metal objects, and thus maintaining the discrimination capability.
The present invention importantly arranges an array of sensors in such a way that the entire sensor array can be placed in proximity to the body of a subject, such as a patient or an attendant. Further, the sensor arrays can be arranged so as to be susceptible to placement in proximity to the body of a subject, such as a patient lying recumbent, as on a stretcher or gurney.
A passive magnetic embodiment of the portal used in one embodiment of the present invention can be similar in some respects to the SecureScan 2000™ weapons detection portal which is manufactured by Quantum Magnetics, Inc., and marketed by Milestone Technology, Inc., or the i-Portal™ weapons detection portal which is marketed by Quantum Magnetics, Inc.
The portal includes two panels of sensors on the sides of the entryway. An array of magnetometers inside each panel enables detection, characterization, and localization of ferromagnetic objects from the soles of the feet to the top of the head. The magnetometer array can take a variety of configurations, and it can use a variety of sensor technologies. For example, a set of 16 single-axis magnetic gradiometers can be arranged with 8 in each panel. Other configurations can include arrays of multi-axis gradiometers, or combinations of single-axis and multi-axis gradiometers. One or more magnetic tensor gradiometers may also be used. A magnetoresistive magnetometer, or any other sensor capable of sensing magnetic field changes at or near zero frequency, can be used.
As shown in FIG. 1 , in order to scan a patient on a gurney, the portal sensor configuration 10 of the present invention can be arranged to bring all of the sensors closer to the patient and to effectively scan a patient in the recumbent position. Rather than being arranged vertically, the two sensor panels 12 , 14 can be arranged horizontally, parallel to the path of the gurney and on either side, as shown in FIG. 1 . This places the sensors in a similar relation to the patient as they would have, in the vertical arrangement, to an ambulatory patient. Also, a single “snapshot” of data covers the entire gurney and patient, as in the ambulatory case. The sensor panels 12 , 14 can be permanently arranged horizontally, or they can pivot to this configuration.
Alternatively, in addition to the vertically arranged sensor panels as in the aforementioned known portals, the portal can have a “dutch door” with an additional, horizontal, sensor panel 16 in the upper half of the door, just high enough to clear a patient on a gurney, as shown in FIG. 2 . As the patient is wheeled under the upper door, the patient would pass in close proximity to the horizontal sensor panel 16 , allowing all of its sensors to scan the patient from head to foot, or vice versa. This gives the best detection and resolution of objects, since more sensors are placed closer to the patient. Then, the attendant would push the dutch door open and walk through the portal, being scanned by the vertically arranged sensor panels. The “dutch door” array 16 can be spring loaded, so that it moves out of the way for an ambulatory subject. A microswitch indicator can tell the software whether the door is engaged, for a recumbent patient, or disengaged, for an ambulatory subject. As a variation of this embodiment, a portal with vertically arranged sensor panels can be situated next to a portal with a horizontally arranged sensor panel, as shown in FIG. 3 .
As an alternative to the passive magnetic portal, an AC or DC magnetizing field can be provided by one or more source coils, a DC field can be provided by a permanent magnet array, or a DC field can be provided in the form of the fringing field of a nearby MRI magnet. In any case, a computer is provided to interrogate the sensors and to interpret the magnetic signals, to detect, characterize, and locate ferromagnetic objects. Characterization of the object provides the size and orientation of its magnetic moment, which can be related to the physical size of the object, and to the magnitude of the attractive magnetic force. The analysis software can use various known algorithms, or a neural network can be used. The information gained can be related to a photographic image of the subject, for the purpose of locating the ferromagnetic object on the subject. A light display can be used to indicate the approximate location of the detected object. System diagnosis, monitoring, and signal interpretation can be done via the Internet, if desired.
The use of AC fields enables the use of induction coil sensors, in addition to or instead of magnetometers, like magnetoresistive, fluxgate, and other types. Induction coil sensors are impossible to use in the DC embodiment because the induction coil has zero sensitivity at zero frequency. Using induction coil sensors typically reduces the cost of the product without sacrificing sensitivity in the AC system.
An AC system could make use of two different excitation directions—operating at two different frequencies, to avoid crosstalk—which can improve detection of long, narrow objects, which are precisely the shape that is most dangerous in this situation.
The excitation frequency is chosen to be low enough so that the magnetization (or, equivalently, magnetic susceptibility) response of objects to be detected exceeds their eddy current response. The choice of frequency is expected to be less than 1 kHz, but it can be as high as 3 kHz in some applications.
The excitation current can be driven by any number of standard drive circuits, including either direct drive (controlled voltage source in series with the coil) or a resonant drive (voltage source coupled to the coil via a series capacitance whose value is chosen such that, in combination with the coil's self-inductance, the current is a maximum at a desired resonant frequency given by ½π(LC) 1/2 ).
The receiver or sensor coil can be made of two coils, wound in opposite senses and connected in series. They form what is well-known as a gradiometer; a uniform magnetic flux threading both coils produces zero response. The coils are distributed symmetrically relative to the excitation coil such that, in the absence of any target object (which is conductive, magnetic or magnetically permeable) nearby, each senses an identical flux from the excitation which thus cancels out.
Although the intent is to make the two coils perfectly identical, and to place them in identically symmetric locations, in practice one falls short of the ideal. As a result, any actual embodiment will display a nonzero response to the excitation, even in the absence of a target; this residual common-mode signal is referred to as an “imbalance” signal. Standard electrical circuits can zero out the imbalance signal by adding an appropriately scaled fraction of the reference voltage V ref (a voltage proportional to the excitation current, obtained by measuring across a series monitor resistor) to the output voltage V out .
When a target object is near to either coil, it spoils the symmetry and thus induces a finite signal. This signal oscillates at the same frequency as the excitation. Standard demodulation or phase-sensitive detection circuits, using V ref as the phase reference, measure the magnitude of V out in phase with V ref and in quadrature (90 degrees out of phase) with V ref . At an appropriately chosen low frequency, the response will be dominated by the susceptibility response, which appears predominantly in the quadrature output, as opposed to the eddy current response, which appears predominantly in the in-phase component.
In principle, the coils could be replaced by two magnetometer sensors (fluxgate, magnetoresistive, magnetoimpedance, etc.). Coils respond to the time derivative of the magnetic field, while magnetometers respond to the field itself; the coil's output voltage is shifted by 90 degrees with respect to a magnetometer's. If magnetometers are used instead of coils, then the susceptibility response would show up in the in-phase component and the eddy current response (at low frequency) in the quadrature component.
If the operating frequency is chosen much too high, both susceptibility and eddy-current responses appear in the in-phase component (using magnetometers) or quadrature component (using coils), but with opposite sign, making it impossible to distinguish between the two. At intermediate frequencies, the eddy current phase is intermediate between the two components, complicating the distinction. Therefore, it is important to choose the excitation frequency to be low enough, and preferably less than about 3000 Hz.
The substrate or coil form must be nonconductive, nonferromagnetic and, with one possible exception, magnetically impermeable (μ=μ o , where μ o is the permeability of free space). The exception is that a magnetically permeable core inside sensor coils having a cylindrical geometry can increase the sensitivity of the system.
The use of a reference sensor helps to eliminate common mode error signals. For instance, a nearby passenger conveyer, such as a gurney, could contain magnetic components, but this spurious magnetization is not what is intended to detect, and, therefore, it is preferable to eliminate this magnetic source.
An audio alert, such as a buzzer, and/or an alarm light can be employed to signal the presence of an unwanted ferromagnetic object.
As shown in FIG. 4 , the sensor's sensitivity axis is orthogonal to the axis of the magnetic field of a permanent magnet 32 . Otherwise stated, the magnetic field of the permanent magnet 32 is normal to the plane of the sensor 34 .
In FIG. 5 , the magnetic field of the DC permanent magnet field source 32 magnetizes the ferromagnetic object, which then has a magnetic field of its own, as shown in FIG. 6 . This induced magnetization (“demag field”) is detected by the sensor 34 , triggering the alarm buzzer and/or light.
An alternative configuration, shown in FIG. 7 , utilizes two permanent magnets 32 A, 32 B, as the magnetic field between them is less divergent than with a single permanent magnet. With the use of two permanent magnets 32 A, 32 B and less resultant divergence, there is less need for criticality about positioning the permanent magnet with respect to the sensor 34 .
FIGS. 8 through 13 show various embodiments of the excitation coil configurations useful with the portal structure, for applying a magnetizing field to the volume of space around a portal, in accordance with the present invention. For the sake of illustration, the portal is assumed to comprise a set of single-axis magnetic field gradiometers in two substantially equal arrays on either side of the opening. The principles can be generalized to portals with gradiometers in other orientations, and with multi-axis gradiometers as well.
The underlying requirement of the applied field is that it should not disturb the sensors. That is, in the absence of a magnetic or magnetizable object in the portal, the field should produce zero signal on the gradiometer outputs. This requirement ensures that variations in the applied field don't show up as noise on the sensors—since the objective is to increase the signal from objects, by increasing the magnetizing field, without increasing the sensor noise.
The requirement can be stated as follows: the magnetizing field should have zero mutual inductance with the sensors. This can be expressed in two forms, with the same net result but with slightly different implementation issues. In one form, the magnetizing field has zero mutual inductance with each magnetometer (a pair of them making one gradiometer). This is a more restrictive requirement than the second form, which specifies zero mutual inductance with each gradiometer.
Assume a coordinate system in which the z-axis points vertically, the x-axis horizontally in the plane of the portal, and the y-axis orthogonally to the plane of the portal. FIGS. 8 through 13 all assume gradiometers measuring the difference in the x-direction of the x-component of the field (written as ∂B x /∂x). FIGS. 8 through 11 illustrate the first form of the requirement (zero coupling to each magnetometer); this is achieved by making the field point entirely in the y-direction (orthogonally to the sensitive axis) at all the sensors.
FIGS. 8 and 9 illustrate a single coil in the portal plane, with FIG. 8 showing the front elevation of the portal, and FIG. 9 showing the right side elevation. Not only is the illustrated coil 40 in the plane of the portal, or as close as possible to it, but the vertical legs run midway between each pair of magnetometers 42 A, 42 B making up the gradiometer pair 42 . Thus, not only is the field perpendicular to the magnetometers' sensitive axis, but each sensor of the pair sees the same field, so any residual field gets canceled on subtraction of one sensor signal from the other, to form the gradient measurement. The coil 40 need not be higher or lower than the portal panels 43 A, 43 B; the components are just shown this way for clarity.
FIGS. 10 and 11 show a pair of coils 44 , 46 on either side of the portal plane, with FIG. 10 showing the front elevation of the portal, and FIG. 11 showing the right side elevation. This optimum arrangement is as a Helmholtz coil pair, but this is not mandatory. The Helmholtz configuration gives the best field uniformity over the portal aperture, but it can add some bulkiness to the apparatus, which can create a problem in some applications, such as an especially “space-challenged” MRI facility. The two coils 44 , 46 overlap. Current runs in the same direction, clockwise in FIG. 10 , in both coils.
FIGS. 12 and 13 illustrate the second form of the requirement (zero mutual inductance with each gradiometer). In this embodiment, each of two coils 48 , 50 creates a field in the x-direction. FIG. 12 shows the front elevation of the portal, and FIG. 13 shows the right side elevation. Positioning is chosen to make the magnetizing field the same at both magnetometers 42 A, 42 B in each gradiometer 42 . Each magnetometer 42 A, 42 B is located at one end of one of the thin lines denoting the gradiometers 42 . By making the excitation field substantially identical for each magnetometer 42 A, 42 B, the differential (gradient) measurement substantially cancels out the excitation field. The two coils 48 , 50 overlap in the view shown in FIG. 13 , and they carry current in the same direction, clockwise in the drawing.
While the particular invention as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages hereinbefore stated, it is to be understood that this disclosure is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended other than as described in the appended claims.
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A method and apparatus to screen individuals specifically for paramagnetic or ferromagnetic objects they may be carrying or wearing, before they enter a controlled area. The device comprises a screening portal, including at least one magnetic gradiometer and its electronics. The device places all of the sensor arrays in close proximity to a subject's body, for screening purposes. The portal has at least one excitation coil oriented to cause the excitation field to have zero mutual inductance with the gradiometers.
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BACKGROUND OF THE INVENTION
The present invention relates to food processors having rotary blades for rapidly slicing or chopping food items, and particularly relates to a method and device for controllably feeding small food items into such a food processor.
Food processors, because of their ability to rapidly slice, pulp, grind, or chop vegetables, fruits, and meats, have become very popular in recent years. Such food processors usually comprise an electric motor connected to drive various interchangeable rotary blades adapted to either slice, chop, grate, or otherwise cut a large piece of food into smaller pieces. Generally each blade is a flat disc having two or more sharp edges. An opening through the disc is generally provided in front of each sharpened edge of the blade, to permit a slice of the food being processed to fall into a receptacle located below the blade.
Food to be processed is introduced through a generally vertical chute which is normally a part of a cover or shroud which encloses the top side of the rotating blade. The chute is located in eccentric relation to the rotating blade, and a pusher whose size and shape correspond to the interior of the chute is used to push food articles downward into contact with the rotating blade.
So long as the feed chute is filled to capacity with food items to be processed, such food processors can quickly cut food items into attractive slices having parallel sides and regular thickness. Because the feed chute is usually an oval tube about 11/2 inches by 3 inches in size, however, processing items such as celery, carrots, cold cuts of meat, and small diameter sausages requires the use of a considerable amount of food to fill the feed chute so that food can be sliced evenly, making use of the processor uneconomical when only small quantities of such items are desired to be sliced.
Another disadvantage of such food processors is that it is very difficult to produce regular slices of unevenly shaped articles of food, particularly articles of small size relative to the inferior dimensions of the feed chute. For example, some foods are easily sliced with such a food processor, but may turn inside the feed chute, resulting in slices which do not have parallel sides. Additionally, stalks of celery, carrot roots, and green onion tops are very difficult to slice evenly using such a food processor.
Slices of small items, such as olives or strawberries, are very attractive as garnishing for salads and the like, and are difficult and time consuming to slice by hand. Slicing such articles by the use of a food processor, however, is also difficult since the article is frequently rotated by the force imparted by the rotating blades of the food processor, with the result that slices are wedge shaped rather than having parallel sides, when the ordinary pusher provided with the processor is used. If food is held by tongs or a fork inside the feed chute, there is a serious danger of the tongs or fork hitting the rapidly spinning blade.
When shredding food, orientation of an oblong piece controls the length of the shreds. Using previously known food processor feeding methods, the pieces of food may be moved by impact of the shredding blade edges, causing uncontrollably irregular shred lengths.
What is desired, then, is a device for feeding articles into a food processor and holding them during processing to permit production of even slices, even when the article being processed is very small in relation to the size of the feed chute of the food processor. Of course, such a device must include provision to prevent its being engaged by the rapidly rotating blades of the food processor, because of the danger involved to the operator, as well as the risk of damage to the food processor.
This problem has apparently not been previously addressed directly, although Campbell U.S. Pat. No. 3,088,345 discloses a kitchen utensil for use in pushing refuse into a rotary garbage disposal unit. The Campbell utensil comprises a flat faced pushing end connected by a shaft to a handle, and includes a cross arm to limit the depth of its insertion into a garbage grinder to prevent interference with the cutting edges of the grinder mechanism.
Azmus U.S. Pat. No. 3,107,711 discloses a similar device for forcing meat into a food grinder, in which the position of the hand relative to the pushing end of the device is adjustable. The handle of the Azmus device also includes a splash guard which extends horizontally around the shaft of the device and limits its insertion into a grinder.
Mueller U.S. Pat. No. 2,066,997 discloses a tamping implement for use in packing vegetables, fruits, and other foodstuffs into containers such as canning jars. One embodiment of the Mueller tamper includes a pliable rubber tip having a V-shaped crotch to aid in gripping the material being packed into a canning jar.
Although the above-described utensils may be useful for forcing material into garbage grinders, meat grinders, and canning jars, none of them is particularly well adapted for use with a food processor to hold small pieces of fruits, vegetables, or meat, to permit the use of a food processor for slicing these food articles into regular flat slices in a safe and efficient manner.
SUMMARY OF THE INVENTION
The shortcomings and drawbacks of the aforementioned previously known devices for forcing articles into garbage grinders, food grinders, canning jars, and the like, which make those devices unsuitable for feeding food into a food processor, are overcome by the present invention, which provides a two-piece device for use in feeding small items into a food processor. The device of the invention comprises a holder which holds pieces of food in place in a tubular feed chute of a food processor and guides them as they are pushed downward by the other piece of the device, a pusher which includes a textured surface on its lower end for engaging the surface of a piece of food and helping to prevent it from turning within the feed chute of the food processor as it is being sliced.
A gauge plate extends horizontally from the upper end of the pusher member to prevent insertion of the pusher too deeply into the feed chute of the processor and to cover the open portion of the feed chute when the pusher is inserted fully therein. A handle is connected to the pusher above the gauge plate.
The holder portion of the food processor feeding device of the present invention comprises a flat guide plate from which a food holding member extends approximately perpendicularly. The food holding member extends from the plate about the same distance as the depth of the feed chute of the food processor, leaving adequate clearance to prevent the food holding member from being struck by the rotary blade of the food processor when the guide plate is in contact with the top of the feed chute. The guide plate, preventing insertion of the food holding member too deeply into the feed chute, also properly orients the food holding member within the feed chute when it rests on the upper edges of the feed chute.
An opening through the guide plate permits the pusher member of the device to be inserted into the feed chute alongside the food engaging, or inner, side of the food holding member. A pair of ear-like grips provided on the top of the guide plate of the holder element of the device are separated from one another and are placed far enough from the food holding member to permit insertion of the pusher element into the feed chute to the full depth established by the gauge plate, even directly alongside the food holding member of the holder.
One side of the food holding member is curved to fit against the interior surface of the feed chute of the processor, while the other side is slightly concave and is provided with parallel ridges or fluting used to engage the surface of pieces of food to prevent the food from twisting within the feed chute, yet allow it to slide downward through the feed chute toward the rotary blade.
The food processor feeding device of the invention thus enables one to evenly slice small items of food, and to slice or shred a long thin item across its length to provide small slices or short shreds.
It is therefore a primary objective of the present invention to provide a device for holding small pieces of food and guiding them into position for slicing in a food processor.
It is another important objective of the present invention to provide a device which permits use of a food processor to process amounts of food too small to be processed otherwise.
It is a further objective of the present invention to provide a device for use with a food processor to enable processing of foods, such as green onion tops, which are very difficult to process otherwise.
It is yet another objective of the present invention to provide a device which securely holds small pieces of food in one orientation during slicing or shredding in a food processor, to produce even, attractive slices or shreds.
It is a primary feature of the present invention that it includes a food holding member having parallel ridges which guide a piece of food as it is fed through the feed chute of a food processor.
It is another important feature of the present invention that the food engaging lower end of the pusher element of the device includes a rough textured surface for engaging a piece of food to control its orientation as it is being processed.
It is another feature of the present invention that the holder and pusher include plates which permit insertion of the food holding member and the pushing member into the feed chute of a food processor to a sufficient depth, yet prevent them from interfering with the blades of the food processor.
It is yet further feature of the invention that the plates included on the holder and pusher cover the opening of the feed chute when fully inserted therein, excluding dust from the interior of the processor while the feeder device of the invention is stored therein.
It is a primary advantage of the present invention that it permits use of a food processor to attractively slice small portions of food which would otherwise have to be prepared by hand.
It is another important advantage of the invention that it enables small pieces of food to be sliced more evenly than with previous methods of using a food processor.
It is another advantage of the present invention that it permits a food processor to be used to slice items of food which would otherwise require hand slicing because of their fragility and shape.
The foregoing and other objectives, features and advantages of the present invention will be more readily understood upon consideration of the following detailed description of the invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view of a food processor feeding device embodying the present invention, being used to feed a single small potato into a food processor for slicing.
FIG. 2 is a partially cut away sectional elevational view of the food processor feeding device and food processor shown in FIG. 1.
FIG. 3 is a sectional view of the food processor feeding device and feed chute shown in FIG. 1.
FIG. 4 is a fragmentary pictorial view of the pusher piece of the feeding device shown in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, a food processor feeding device 10 is shown in FIG. 1 in use with a food processor 12 which includes a feed chute 14 extending upwardly above the upper surface of a protective shroud 16 which supports the feed chute 14. Below the protective shroud 16 is a disc-like rotary blade 18 which includes appropriate cutting edges, such as the slicing edges 20 and also having a plane of rotation. A slot 22 in front of each slicing edge 20 permits slices to pass downward through the rotary blade 18 into a receptacle as the shaft 24 (FIG. 2) turns the rotary blade 18 in the direction indicated by the arrow 26.
The feeding device 10 comprises two separate elements, a holder 28 located within the tubular feed chute and movable in a plane parallel to the plane of rotation of the rotary blade and a pusher 30. The holder 28 includes an elongate food holding member 32 which is attached to a guide plate 34. The food holding member 32 has an arcuate outer side 36 and an inner side 38, which may be generally flat, or slightly concave across its width to assist in orienting pieces of food and which includes vertically oriented ridges 40 extending along its full length, to guide food toward the rotary blade 18 and resist any twisting force resulting from cutting edges impacting against the food being processed.
The guide plate 34 is a flat member including a cover portion 42 which is large enough to close the opening in the top of the feed chute 14. The food holding member 32 extends generally perpendicularly from the bottom side of the guide plate 34, so that the inner side 38 is generally parallel with the interior surface 44 of the end 45 of the feed chute toward which the sharp edges of the rotary blade 18 move.
The cover portion 42 extends in the direction of the outer side 36 of the food holding member 32, and a rim 46 extends away from the cover portion 42 in the direction of the inner side 38 of the food holding member 32, defining an opening equal in size to the top opening of the feed chute 14, except for the portion of the feed chute occupied by the food holding member 32 when the food holding member 32 is held with its outer side 36 against the interior surface 44 of the feed chute 14. The cover portion 42 and rim 46 of the guide plate 34 are coplanar and when resting in contact with the upper edge 48 of the feed chute 14 they orient the food holding member 32 in a directly downward extending direction.
A pair of handles 50, which are preferably small, ear-like members, extend upwardly from the cover portion of the guide plate 34. The handles 50 are separated from one another, permitting the user to conveniently and securely grip the holder 28 with a finger on one of the handles 50 and the thumb on the other.
The pusher 30 comprises a shaft 52 which has an arcuate outer side 54 and a flat inner side 56, the cross sectional shape of the shaft 52 thus being approximately similar to the shape of the food holding member 32. A gauge plate 60, which may be circular, extends radially from the upper end of the shaft 52. The gauge plate 60 is large enough to engage the top of the guide plate 34 to prevent the shaft 52 from being extended so far into the feed chute 14 that the rotary blade 18 might strike the pusher. The gauge plate 60 also prevents spattering of juice from the feed chute 14 as the last of the food is processed, and covers the open upper end of the feed chute, when the feeding device 10 is stored therein. A lower end surface 58 of the shaft 52 has a food gripping texture, for example a knurled surface, as may be seen in FIG. 4. This is provided to aid in controlling and manipulating food items to orient them in a desired direction. A handle such as the knob 62 is provided above the gauge plate 60.
Because of the differences in the size of the feed chutes of various food processors, slight variations in the size of the elements of the feeding device 10 will be necessary to allow its use with different models of food processors. In general, however, the length of the food holding member 32 should be approximately the same as the length of the feeding device originally provided with a food processor, in order to provide a safe amount of clearance between the lower end of the food holding member 32 and the rotary blade 18 of the food processor. The length of the shaft 52 of the pusher 30 should be similar, although it may be longer by an amount equal to the thickness of the guide plate 34, to prevent interference with the rotary blade 18.
While other materials may also be found to be usable, the feeding device 10 of the present invention may preferably be manufactured of a plastic material such as an injection moldable transparent plastic which is sufficiently heat tolerant to permit washing in a dishwasher.
The feeding device 10 of the present invention is used by gripping the handles 50 of the holder 28 between the thumb and finger of one hand and inserting the food holding member 32 downward into the feed chute 14 of the food processor. If the processor rotates counter-clockwise, the opening defined by the rim 46 should be to the right, and if rotation is clockwise the rim 46 should be to the left, when the feed chute 14 is on the side of the processor nearest to the operator. With the processor power turned off, food to be processed may be placed downward into the feed chute 14 through the opening in the guide plate 34, between the inner side 38 of the food holding member 32 and the inner surface 44 of the feed chute, at the trailing end 45, the end of the oval opening of the feed chute toward which the cutting edges of the rotary blade 18 are directed. A long piece of food may be inserted by hand for slicing across its length, while a fork may be used to place a small item in place. The food holding member 32 is then manipulated with one hand to hold each article of food between the inner side 38 of the food holding member and the inner surface 44 of the feed chute 14, with the guide plate 34 resting on the upper edge 48 of the feed chute 14, and any fork, etc. is removed from the feed chute. If the piece of food is long and tapered, as in the case of a carrot, it may be advantageous to tilt the holder 28 to bring more of the inner side 38 into contact with the food than if the guide plate 34 is in contact with and parallel to the upper edge 48.
With the free hand, the processor motor is turned on, after which the pusher 30 is used by grasping the knob 62 and inserting the shaft 52 downward into the feed chute 14, so that the lower end surface 58 engages the upper surface of the piece of food, for instance a potato 66. With the food processor activated, the pusher 30 is used to urge the food downward to be sliced by the slicing blades 20 or otherwise processed by an appropiate type of blade 18. The food-engaging end surface 58 of the pusher 30, because of its rough texture, cooperates with the ridges 40 to prevent the potato or other food item from rotating as a result of the force imparted by the slicing edges 20 of the rotary blade 18, resulting in production of slices 68 which have parallel sides and are of even thickness.
In addition to permitting even slicing of such easily managed food as potatoes, the feeding device of the invention permits such articles as small bunches of green onion stalks to be chopped. This is best accomplished by bending a small bunch of the onion stalks into a "U" shape and placing the "U"-shaped bunch into the feed chute 14 with the bottom of the "U" uppermost. The ridges 40 help retain the orientation of the onion stalks while the pusher 30 forces the onion stalks downward for slicing by the rotary blade 18.
In a similar fashion such delicate items as strawberries may be sliced, the feeding device 10 of the invention permitting control of individual berries to prevent rotation and produce attractive slices of regular thickness and parallel sides.
For slicing foods of which a large quantity would be necessary to fill the entire feed chute 14, the feeding device 10 of the invention permits small quantities to be properly processed. For instance, single stalks of celery, single carrot roots, small sausages, sticks of cheese, and rolled slices of luncheon meat, ham, and the like may be quickly sliced by the food processor when the device 10 of the present invention is used.
For shredding items into short shreds, the item may be cut into stick-like pieces which are thick enough to permit insertion of the shaft 52 of the pusher 30 between the food holding member 32 and the inner surface 44 of the feed chute 14 while holding the food with the food holding member 32. The food is then pushed along the food holding member 32, guided by the ridges 40, and shreds produced are as long as the thickness of the stick-like piece of food.
The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.
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A two-piece device for use in holding and guiding items of food, particularly small items, into position for slicing or other processing by the cutting blades of a food processor comprises a holder including an elongate food-holding member for pressing pieces of food against an inner surface of the feed chute of the food processor, and an elongate pusher having a food-engaging end, for controlling and pushing pieces of food along the holder toward the rotary blades of the food processor. A guide plate, to which the food holding element of the holder is connected, orients the food holding element and covers a portion of the feed chute. A gauge plate connected with the pusher prevents insertion of the pusher into the feed chute beyond a safe depth, and covers the remainder of the opening of the feed chute when fully inserted therein.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a National Stage of International Application No. PCT/EP2009/004815, filed Jul. 3, 2009. This application claims the benefit and priority of German application 10 2008 035 915.7 filed Jul. 31, 2008. The entire disclosures of the above applications are incorporated herein by reference.
BACKGROUND
This section provides background information related to the present disclosure which is not necessarily prior art.
1. Technical Field
The invention relates to a manipulation detection system for removable insertable cash cartridges in automated banking machines (ABMs). Generic cash cartridges have a lockable cash dispensing/deposit opening for disbursing money and/or depositing money when in the operating position in the automated banking machine.
2. Discussion
Discussion For security reasons, it is important to know whether the cash dispensing/deposit opening of the cash cartridge has been opened without authorization outside the automated banking machine in order to remove bank notes. In this regard, it is of particular interest whether a) the cash cartridge was opened in the time period between being filled with bank notes at a bank or a valuables transport company and its deployment in an automated banking machine, and b) whether the cash cartridge was opened in a time period between its removal from an automated banking machine and the official opening at a bank or a valuables transport company.
For this reason it is proposed in DE 690 04906 T2 that to recognize manipulation via a sensor that detects the opening of the cash dispensing/deposit opening, a manipulation alert is generated at the cash cartridge. A manipulation alert of this type can be used specifically to activate a dye pack located in the cash cartridge. Money in the cash cartridge, particularly bank notes, can thereby be rendered unusable by being dyed with a special ink.
In a system consisting of automated banking machine and cash cartridge, in which, due to the design of the system, the money dispensing/deposit opening is opened automatically, for example by a guide, when inserted into the automated banking machine before reaching the operating position, this opening of the dispensing/deposit opening is problematic to the extent that this permissible opening can erroneously result in a manipulation alert at the cash cartridge. Such a manipulation alert in cash cartridges with a dye pack would lead to undesirable activation of the dye pack which would result in great losses.
SUMMARY OF THE INVENTION
An object of the invention is, therefore, to develop a manipulation detection system that can distinguish in a simple and reliable way between authorized opening of the cash dispensing/deposit opening of a cash cartridge inside the automated banking machine and unauthorized opening outside the automated banking machine.
In accordance with the invention, at least two, preferably three switches are provided in the cash cartridge that are automatically actuated when the cash cartridge is inserted into the automated banking machine. In order to generate a manipulation alert (i.e., some response due to unauthorized tampering) , the switch actuation sequence of the at least two switches is evaluated using predefined criteria. Unauthorized opening of the cash dispensing/deposit opening outside the ABM always leads to a manipulation alert, and in the case of cash cartridges with a dye pack, to activation of said pack because the specified switch actuation sequence does not occur in this instance. The more switches that are used, the more complex the switch actuation sequence and the more reliably manipulation is detected. Through the use of three switches, a very high degree of reliability and security is obtained at an acceptable cost.
In accordance with the invention, an automated banking machine is understood to mean any automat for depositing or dispensing money using cash cartridges. The term automated banking machine includes both self-service and staffed automats, e.g. so-called automatic teller safes. The generic automated banking machine can be operated in a retail operation, for example, in conjunction with a payment station as a point-of-sales terminal.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
Using the appended drawings, the invention is to be explained in greater detail in what follows:
FIGS. 1A-1D show different phases when inserting the cash cartridge into the automated banking machine,
FIG. 2 shows timing diagrams for the switch actuations,
FIG. 3 shows a block diagram of a cash cartridge with the components located therein.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Example embodiments will now be described more fully with reference to the accompanying drawings.
An automated banking machine ( 1 ) with a cash cartridge ( 2 ) is shown schematically in FIGS. 1A to 1D , where various phases during the insertion of the cash cartridge are shown. The cash dispensing/deposit opening ( 2 C) is located essentially on the front side of the cash cartridge ( 2 ). To close this opening ( 2 C), for example, a blind or shutter is provided. The cash dispensing/deposit opening ( 2 C) is opened automatically by a slotted guide (not shown) before it has reached its operating position when the cash cartridge ( 2 ) is inserted into the automated banking machine ( 1 ). This happens, for instance, by a blind being slid open. The displacement of the blind is shown schematically and identified with the reference numeral 2 B. The insertion of the cash cartridge ( 2 ) preferably takes place by pushing the cash cartridge ( 2 ) into a frame in the automated banking machine ( 1 ).
Three switches (S 1 , S 2 , S*) are provided in the cash cartridge that are actuated automatically in a specific, pre-determined sequence when the cash cartridge ( 2 ) is inserted into the automated banking machine ( 1 ). In addition, the cash cartridge has a plug ( 2 A) that, in the fully inserted position (operating position), is connected to a mating connector ( 1 C) in the automated banking machine to provide energy and/or data transmission between the automated banking machine and the cash cartridge ( 2 ). A magnet ( 1 A) is shown schematically as a component of the automated banking machine, the function of which will be explained later.
As depicted in FIG. 1A , the cash cartridge ( 2 ) has already been pushed far enough into the automated banking machine ( 1 ) that the cash dispensing/deposit opening ( 2 C) has been opened slightly. At time TO, the switch (S 1 ) in the cash cartridge is actuated. Switch (S 1 ) is preferably a mechanically actuatable switch, e.g. a pushbutton switch that is actuated, for instance, by the displacement of the blind or shutter.
As depicted in FIG. 1B , the cash cartridge ( 2 ) has been pushed further into the automated banking machine compared with the position of FIG. 1A . In this position, the switch (S*) in the cash cartridge is actuated at time T 1 . In the case of switch (S*), it is preferably a Hall switch that is actuated when it detects a magnetic field with a magnetic field strength that lies above a certain threshold. The Hall switch (S*) is thus actuated when the Hall switch (S*) is moved into the effective range of the magnet ( 1 A) as the cash cartridge ( 2 ) is inserted. This is the case—as shown in FIG. 1 B—at time T 1 when the Hall switch (S*) and the magnet ( 1 A) lie directly opposite each other and the distance between Hall switch (S*) and magnet ( 1 A) is minimal.
As shown in FIG. 1C , the cash cartridge ( 2 ) has been pushed further into the automated banking machine compared with the position of FIG. 1B . In this position, the cash dispensing/deposit opening ( 2 C) is already almost completely open. The Hall switch (S*) is no longer within the effective range of the magnet ( 1 A) in this position. The switch (S 2 ) is actuated in this position at time T 2 . As in the case of switch (S 1 ), switch (S 2 ) is preferably a mechanically actuatable switch, e.g. a pushbutton switch that is actuated for example by the displacement of the blind or shutter.
As shown in FIG. 1D , the cash cartridge ( 2 ) is located in the completely inserted position, i.e. in the operating position. In this position, the cash dispensing/deposit opening ( 2 C) is fully open. Additionally, the plug ( 2 A) for the cash cartridge and the mating connector ( 1 C) of the automated banking machine ( 1 ) are in electrical contact with each other. In the operating position, money can be removed from and/or deposited into the cartridge ( 2 ) by way of a module ( 1 B) located in the automated banking machine ( 1 ).
The switch times T 0 , T 1 and T 2 are indicated symbolically in FIGS. 1A-1C at the locations where the front face of the cash cartridge ( 2 ) has reached the respective positions at which switches S 1 , S* or S 2 are actuated.
The sequence of switch actuations (S 1 →S*→S 2 ), as was explained using FIGS. 1A-1D , is shown again in the timing diagram in FIG. 2 . Also shown there is the switch position (also known as switch status) for each of the switches (S 1 , S 2 , S*) relative to the time when the cash cartridge ( 2 ) was inserted. Switch (S 1 ) is the first to be actuated, where the actuation of this switch (S 1 ) defines time T 0 . At time T 1 , the Hall switch (S*) is actuated. As soon as the Hall switch (S*) has left the effective range of the magnet ( 1 A) as the cash cartridge ( 2 ) is inserted further, the switch status of the Hall switch (S*) returns from “On” to “Off”. At time T 2 , switch (S 2 ) is actuated as the last of the three switches.
In one embodiment of the invention provision is made for switches S 1 and S 2 to remain in the “On” status after actuation until the cash cartridge ( 2 ) is in the operating position at time T stop , which is detected through the plug contact (cash cartridge plug/mating connection of automated banking machine).
In an alternative embodiment, provision is made for switches S 1 and S 2 to remain in the “On” status after actuation until the cash dispensing/deposit opening ( 2 C) is closed again after being removed from the automated banking machine ( 1 ).
In further alternative embodiment, provision is made for switches S 1 and S 2 to return automatically again from status “On” to status “Off” after a certain time following actuation.
A manipulation alert is always generated when the switch actuation sequence detected does not match the previously defined switch actuation sequence for the system. The pre-defined switch actuation sequence is determined as follows:
First, actuation of switch S 1 (Off→On), then actuation of switch S* (Off→On) and then actuation of switch S 2 (Off→On).
In a further developed variant, the pre-defined resetting of switch (S*) in the switch actuation sequence is scanned:
First, actuation of switch S 1 (Off→On), then actuation of switch S* (Off→On), then the resetting of switch S* (On→Off), and then actuation of switch S 2 (Off→On).
The more complex the pre-defined switch actuation sequence is, the more difficult it is to imitate said sequence outside the automated banking machine.
Furthermore, provision is also made not only to scan the sequence of switch actuation per se but also whether said sequence took place within a pre-determined time period (ΔT). For this reason, a mechanical resistance to insertion (not shown) is provided that has to be overcome in terms of time when inserting the cash cartridge ( 2 ) before the first switch (S 1 ) is actuated. To overcome this resistance, the operator has to exert a certain minimum force when inserting the cash cartridge which ensures that after overcoming this resistance, a maximum time is not exceeded to complete the subsequent distance over which the three switches (S 1 , S*, S 2 ) are then actuated. In other words, overcoming the resistance to insertion effects sufficient impetus so that the time period between actuation of the first switch (S 1 ) and the last switch (S 2 ) can be reduced to a calculable maximum amount.
Provision is further made in one embodiment to scan the time intervals between actuation of the individual switches.
The pre-defined criteria, using which the switch actuation sequence detected is evaluated, are accordingly: fixed sequence for switch actuation and/or reset, time period for the actuation of all switches and/or time intervals between individual switch actuations.
Through the use of at least one non-mechanically actuatable switch S* (e.g. in the form of a Hall switch), which requires a further element (e.g. magnet) located on the automated banking machine ( 1 ) for its actuation, the reliability of the manipulation detection system is substantially increased because a fraudulent re-creation of the switch activation sequence presupposes precise knowledge of the magnet, its strength, installation location and distance to the Hall sensor at the time of actuation.
In the manipulation detection system in accordance with the invention, generation of a manipulation alert is used specifically to activate a dye pack located in the cash cartridge ( 2 ) in order make the money in the cash cartridge ( 2 ) unusable by dying said money with ink in the event of manipulation (=unauthorized opening of the cash dispensing/deposit opening outside the automated banking machine). Alternatively or additionally, the manipulation alert can also be used to generate an optical and/or acoustic manipulation alert signal at the cash cartridge ( 2 ). The manipulation alert can also be saved in a manipulation memory (not shown) of the cash cartridge ( 2 ).
In one embodiment of the invention, provision is made to use the actuation of one of the three switches (S 1 , S 2 , S*) to generate a provisional manipulation alert, where this provisional manipulation alert is canceled if the evaluation of the switch actuation sequence shows that no manipulation has taken place. Only if the evaluation of the switch actuation sequence shows that manipulation has taken place, does the preliminary manipulation alert became a final manipulation alert, which then results in activation of a dye pack for example. The use of switch (S 2 ) is particularly suitable for generating a preliminary manipulation alert because the switch (S 2 ) is actuated when the cash dispensing/deposit opening ( 2 C) is already almost fully open.
The manipulation detection system in accordance with the invention, which is specifically also intended to prevent the generation of an unwanted manipulation alert during insertion into an automated banking machine ( 1 ), has the advantage that it also operates if the power supply to the automated banking machine ( 1 ) fails when the cash cartridge ( 2 ) is inserted since the switches (S 1 , S 2 , S*) and the evaluation for the detection of manipulation are located in the cash cartridge ( 2 ) that uses an independent power supply, e.g. through a battery. In this way, erroneous triggering of the dye pack when the cash cartridge ( 2 ) is inserted can be reliably prevented if the power supply for the automated banking machine fails.
FIG. 3 shows a block diagram for a cash cartridge with the components located therein. The battery supplies the remaining components with energy (current, voltage). In the operating position, the components can also be supplied with energy through the plug from the automated banking machine. The switch modes of the three switches are scanned and evaluated by an evaluation and control unit in order to check whether the switch actuation sequence scanned matches the pre-defined criteria. The timer is started with the actuation of the first switch (S 1 ), which defines time T 0 . Actuation of the last switch (S 2 ) at time T 2 defines the end of the switch actuation sequence, where ΔT=T 2 −T 1 .
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the invention, and all such modifications are intended to be included within the scope of the invention.
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A manipulation detection system for removable insertable cash cartridges in automated banking machines is described,
wherein the cash cartridge has a lockable cash dispensing/deposit opening for disbursing money and/or depositing money in the operating position of the cash cartridge, wherein the cash dispensing/deposit opening is opened automatically when the cash cartridge is inserted into the automated banking machine even before said cassette reaches its operating position, wherein when the cash dispensing/deposit opening is opened, a manipulation alert is generated at the cash cartridge by means of a sensor.
The system is also characterized in that
at least two switches (S 1 , S 2 , S*) are provided in the cash cartridge, the at least two switches (S 1 , S 2 , S*) are actuated automatically when the cash cartridge is inserted into the automated banking machine, the switch actuation sequence of the at least two switches (S 1 , S 2 , S*) is evaluated using pre-determined criteria for the generation of a manipulation alert.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a process for transporting hydrates of natural gas, petroleum gas or other gases in suspension in a fluid comprising water, one of said gases and a liquid hydrocarbon.
[0003] More particularly, it relates to a process in which a composition is used which comprises at least one ester associated with a non-ionic surfactant of the polymerized (dimer and/or trimer) carboxylic acid type.
[0004] Gases which form hydrates may comprise at least one hydrocarbon selected from methane, ethane, ethylene, propane, propene, n-butane and isobutane, and possibly H 2 S and/or CO 2 .
[0005] Said hydrates form when water is in the presence of gas either in the free state or in the dissolved state in a liquid phase such as a liquid hydrocarbon and when the temperature reached by the mixture, in particular water, gas and possibly liquid hydrocarbons, such as oil, drops below the thermodynamic hydrate stability temperature, said temperature being given for a known gas composition when the pressure is fixed.
[0006] Hydrate formation is notorious particularly in the gas and oil industry where hydrate formation conditions may occur. To reduce the cost of crude oil and gas production, both from the point of view of investment and from the exploitation point of view, one possible route, in particular for offshore production, is to reduce or do away with the treatments applied to crude oil or gas to be transported from the field to the coast and to leave all or some of the water in the fluid to be transported. Such offshore treatments are generally carried out on a platform located on the surface close to the field, so that the effluent, which is initially hot, can be treated before the thermodynamic hydrate stability conditions are reached due to cooling of the effluent by sea water.
[0007] However, as this occurs in practice when the thermodynamic conditions required to form hydrates are satisfied, hydrate agglomeration causes the transport lines to block by creating plugs which prevent the passage of crude oil or gas.
[0008] The formation of hydrate plugs may cause production to stop, and thus engender large financial losses. Further, restart of a facility, especially if it involves offshore production or transport, may be lengthy as it is difficult to decompose the hydrates formed. In fact, when the production of a submarine field for natural gas or oil and gas comprising water reaches the surface of the sea bed and is then transported on the sea bottom, the drop in temperature of the effluent means that the thermodynamic conditions for hydrate formation are satisfied; they agglomerate and block the transfer lines. The temperature on the sea bottom may, for example, by 3° C. or 4° C.
[0009] Conditions favorable to the formation of hydrates may also occur on land for lines which are above ground or are not deeply buried in the ground when, for example, the ambient air temperature is cold.
[0010] 2. Description of Related Art
[0011] To overcome such disadvantages, the prior art has sought to use products which, when added to fluid, can act as inhibitors by reducing the thermodynamic hydrate stability temperature. They are alcohols such as methanol or glycols such as mono-, di- and tri-ethylene glycol. That solution is very expensive as the quantity of inhibitors to be added may reach 10% to 40% of the water content; further, such alcohols pollute the effluents as such inhibitors are difficult to recover.
[0012] Insulation of the transport lines has also been recommended to prevent the temperature of the transported fluid from reaching the hydrate formation temperature under the operating conditions. Again, such a technique is very expensive.
[0013] Further, a variety of non-ionic or anionic surfactants have been tested for their hydrate formation retarding ability in a fluid comprising a gas, in particular a hydrocarbon, and water. An example which may be cited is the article by Kuliev et al: “Surfactants Studied as Hydrate Formation Inhibitors”, Gazovoe Delo No. 10, 1972, 17-19, reported in Chemical Abstracts 80, 1974, 98122r.
[0014] Further, the use of additives capable of modifying the hydrate formation mechanism has been described since, instead of rapidly agglomerating to form plugs, the hydrates formed disperse in the fluid without agglomerating and without obstructing the lines. In this regard, the Applicant's European patent application EP-A-0 323 774 may be cited, which describes the use of non-ionic amphiphilic compounds selected from esters of polyols and substituted or unsubstituted carboxylic acids, and compounds with an imide function; EP-A-0 323 775, also in the Applicant's name, describes the use of compounds belonging to the fatty acid diethanolamide or fatty acid derivative family; United States patent U.S. Pat. No. 4,856,593 describes the use of surfactants such as organic phosphonates, phosphate esters, phosphonic acids, their salts and their esters, inorganic polyphosphates and their esters, as well as polyacrylamides and polyacrylates; and EP-A-0 457 375, which describes the use of anionic surfactants such as alkylarylsulfonic acids and their alkali metal salts.
[0015] Amphiphilic compounds obtained by reacting at least one succinic derivative selected from the group formed by polyalkenyl succinic acids and anhydrides on at least one polyethylene glycol monoether have also been proposed to reduce the tendency of natural gas, petroleum gas or other gases to agglomerate (patent application EP-A-0 582 507).
BRIEF SUMMARY OF THE INVENTION
[0016] We have now discovered that, to transport hydrates in suspension in a fluid comprising water, gas and a liquid hydrocarbon, it is particularly advantageous to use as an additive one or more compositions comprising at least one ester, associated with a non-ionic co-surfactant of the polymerized (dimer and/or trimer) carboxylic acid type.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Thus, the invention proposes a process for transporting hydrates in suspension in a fluid comprising at least water, a gas and a liquid hydrocarbon under conditions in which hydrates may form from water and gas, wherein an additive comprising at least one composition comprising at least one constituent A consisting of at least one ester formed between at least one linear or branched monocarboxylic acid and at least one linear or branched alcohol (monoalcohol or polyol), and at least one constituent B consisting of at least one polymerized fatty acid, is incorporated into said fluid.
[0018] The ester may be obtained by esterification, transesterification or interesterification.
[0019] More particularly, constituent A consists of at least one ester formed between at least one linear or branched monocarboxylic acid containing 8 to 24 carbon atoms, more particularly 14 to 18 carbon atoms, and at least one linear or branched alcohol containing 2 to 200 carbon atoms, more particularly 6 to 30 carbon atoms.
[0020] The acid may, for example, be a linear or branched, saturated or unsaturated or hydroxylated monocarboxylic acid having, for example, one of the following formula in which n=7:
[0021] CH 3 —(CH 2 ) n —COOH (octanoic acid)
[0022] CH 3 —CH(CH 3 )—(CH 2 ) n —COOH (undecenoic acid)
[0023] CH 3 —CH 2 —CH(CH 3 )—(CH 2 ) n —COOH (lauric acid)
[0024] CH 3 —(CH 2 ) n —CH═CH—(CH 2 ) n —COOH (oleic acid)
[0025] CH 3 —(CH 2 ) n−2 —CH(OH)—CH 2 —CH═CH—(CH 2 ) n —COOH (ricinoleic acid)
[0026] CH 3 —(CH 2 ) n−1 -(CH═CH—CH 2 —CH═CH)—(CH 2 ) n —COOH (arachidic and gadoleic acids)
[0027] CH 3 —(CH 2 ) n —(CH═CH—CH═CH—CH═CH)—(CH 2 ) n —COOH (erucic acid)
[0028] The alcohol may be:
a monoalcohol: primary: R—CH2-OH; secondary: (R-)2CH—OH; tertiary: (R-)3C—OH; in which R═C x H y , x=1 to 21 and y=2x+1; a polyhydroxylated alcohol, in particular: a diol, such as: ethylene glycol and its polymers: HO—(CH 2 —CH 2 )—OH; HOCH 2 —CH 2 —O(CH 2 —CH 2 —O) m —CH 2 —CH 2 OH in which m=1 to 100; propylene glycol: CH 3 —CHOH—CH 2 —OH; neopentyl glycol: HOCH 2 —C(CH 3 )(CH 3 )—CH 2 OH a triol, such as: glycerol: CH 2 OH—CHOH—CH 2 OH; trimethylolpropane: CH 2 OH—C(CH 2 OH)(CH 2 OH)—CH 2 CH 3 ; a tetra-alcohol, such as: pentaerythritol: (CH 2 OH) 4 C; a hexol, such as: sorbitol: CH2OH—CHOH—CHOH—CHOH—CHOH—CH2OH and its cyclic anhydride, sorbitan, or a sorbitan derivative; a polyglycerol: CH 2 OH—CHOH—CH 2 —(O—CH 2 —CHOH—CH 2 ) p —O—CH 2 —CHOH—CH 2 OH in which p=1 to 8.
[0051] The polyols may be completely or partially esterified, depending on the fatty acid/alcohol stoichiometry employed during the esterifcation reaction, the nature of the fatty acids being as described above.
[0052] More particularly, the hydrophilic/lipophilic balance (HLB) of the ester is generally in the range 2 to 12, preferably in the range 3 to 8.
[0053] The preferred ester of the invention is an ester or a mixture of esters of sorbitol, sorbitan or its derivatives, more particularly the mixture designated as sorbitan monooleate.
[0054] Constituent B present in the mixture used in the invention is derived from dimerization of unsaturated monocarboxylic fatty acids containing 8 to 18 carbon atoms, for example. The reaction product provides a mixture of compounds containing 16 to 80 carbon atoms and constituted by a mixture of monomers, dimers, trimers and higher oligomers, more particularly dimers (16 to 36 carbon atoms).
[0055] The dimers may be represented by the following formula:
[0056] in which the sum q+r may take the value 4 to 14.
[0057] The trimers may have the formula:
[0058] in which the sum q+r may take the value 4 to 14.
[0059] Constituent B is preferably a mixture of dimers of a monounsaturated fatty acid containing 16 carbon atoms (palmitic acid) and a monounsaturated fatty acid containing 18 carbon atoms (oleic acid).
[0060] Preferably, the mixture in the fluid of the invention will comprise 10% to 95% by weight, preferably 30% to 90% by weight and more preferably 50% to 80% by weight of constituent A. The co-surfactant (constituent B) then represents 5% to 90% by weight, preferably 10% to 70% by weight and more preferably 20% to 50% by weight of the mixture.
[0061] In their use as additives to reduce the tendency of hydrates to agglomerate, said compositions are added into the fluid to be treated in concentrations of 0.1% to 5% by weight in general, preferably 0.2% to 3% by weight with respect to the liquid hydrocarbon.
[0062] To test the efficacy of the products used in the process of the invention, the transport of hydrate forming fluids such as petroleum effluents was simulated and tests for the formation of hydrates from gas, condensate and water were carried out using the apparatus described below.
[0063] The apparatus comprises a 10 meter loop constituted by tubes with an internal diameter of 7.7 mm; a 2 liter reactor comprising a gas inlet and outlet, an intake and return for the mixture: condensate, water and additive initially introduced. The reactor allows the loop to be placed under pressure.
[0064] Tubes with a diameter analogous to those of the loop ensure fluid circulation from the loop to the reactor and conversely, via a gear pump placed between the two. A sapphire cell integrated into the circuit allows the circulating liquid and hydrates, if they are formed, to be viewed.
[0065] To determine the efficacy of the additives of the invention, the fluids (water, oil, additive) are introduced into the reactor; the facility is then heated under a pressure of 7 MPa. Homogenization of the liquids is ensured by circulating them in the loop and the reactor, then only in the loop. While monitoring the variations in pressure drop and flow rate, a rapid reduction in temperature from 17° C. to 4° C. (temperature below the hydrate formation temperature) is imposed then kept at this value.
[0066] The test duration may vary from a few minutes to several hours: a high performance additive can maintain circulation of the suspension of hydrates with a stable pressure drop and a stable flow rate.
[0067] The entire disclosure of all applications, patents and publications, cited above and below, and of corresponding French application 04/13304, filed Dec. 13, 2004, are hereby incorporated by reference.
[0068] The following examples illustrate the invention but should not be considered to be limiting.
EXAMPLE 1
Comparative
[0069] In this example, a fluid composed of 10% water and 90% condensate was employed.
[0070] The composition by weight of the condensate was:
for molecules containing less than 11 carbon atoms:
20% paraffins and isoparaffins, 48% of naphthenes, 10% of aromatics; and
for molecules containing at least 11 carbon atoms:
22% of a mixture of paraffins, isoparaffins, naphthenes and aromatics.
[0075] The gas used comprised-98% of methane and 2% of ethane by volume. The experiment was carried out at a pressure of 7 MPa, kept constant by adding gas, with a liquid flow rate of 110 kg/hour. Under these conditions, formation of a plug was observed in the loop several minutes after the onset of hydrate formation (at a temperature of about 10.8° C.): the hydrates formed a block and fluid circulation became impossible.
EXAMPLE 2
[0076] In this example, the procedure of comparative Example 1 was followed using the same fluid, the same gas, at the same pressure and with the same flow rate, but 1% by weight with respect to the volume of condensate of a mixture in accordance with the invention containing 70% by weight of sorbitan monooleate and 30% by weight of C16-C18 fatty acid dimer was added to the circulating fluid. Under these conditions, an increase in the pressure drop during hydrate formation (at a temperature of about 10° C.) was observed, followed by its reduction and stabilization over more than 24 hours at a temperature of 4° C. A drop in temperature to 0° C. did not affect circulation of the suspension; the hydrates remained dispersed in the fluids.
EXAMPLE 3
Toxicity and Biodegradability of the Mixture of the Invention (“Water Hazard Classes” “WGK”)
[0077] The classification “WGK” is given in accordance with the “Administrative Regulation on the Classification of Substances Hazardous to Waters into Water Hazard Classes” (Verwaltungsvorschrift wassergefahrdende Stoffe—VwVwS) dated 17 th May 1999. the classification “WGK” of a mixture can be determined, in accordance with Annex 4 of the new “VwVwS” regulations, by a calculation starting from the “WGK” classification of each constituent of a mixture or on the basis of the results of eco-toxicological tests carried out on the mixture.
[0078] Tests were carried out on constituents A and B of the mixture described in Example 2, used in accordance with the invention.
[0079] 1) Acute oral toxicity in rat, OECD 401: the lethal dose, LD50, was 15900 mg/l;
[0080] 2) WGK=1;
[0081] 3) Acute toxicity OECD 203:
LC50 (24 h): no acute toxicity; LC50 (48 h): no acute toxicity; LC50 (72 h): no acute toxicity; LC50 (96 h): no acute toxicity.
[0086] 4) Biodegradation OECD 301D (28 d): easy biodegradability—83.3%.
[0087] The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and/or operating conditions of this invention for those used in the preceding examples.
[0088] From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.
[0089] The entire disclosures of all applications, patents and publications, cited herein and of corresponding French application No. 04/13.304, filed Dec. 13, 2004 are incorporated by reference herein.
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In order to transport hydrates in suspension in a fluid comprising water, gas and a liquid hydrocarbon, at least one non-polluting composition consisting essentially of a mixture comprising at least one ester associated with a non-ionic co-surfactant of the polymerized (dimer and/or trimer) carboxylic acid type is incorporated into said fluid. The composition is generally introduced in a concentration of 0.1% to 5% by weight with respect to the liquid hydrocarbon.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to the field of wireless communications. More particularly, the present invention relates to uplink enhancements in the air interface between a terminal and a base station in a wireless communications network.
[0003] 2. Description of the Related Art
[0004] The air interface between a terminal and a base station in a wireless communications network relates directly to the achievable level of performance of the network. It is essential to have a low signal-to-interference ratio (SIR) requirement for sufficient link performance with various coding and diversity solutions in the physical layer, since the physical layer defines the fundamental capacity limits of the air interface.
[0005] In 3 rd generation wireless communications systems, such as that specified by Release '99 or subsequent releases of the 3rd Generation Partnership Project joint standardization project (www.3gpp.org), the physical layer is not designed around a single service, such as voice; more flexibility is necessary to enable dynamic scheduling of multimedia services. In Release '99, 3GPP TS 25.211-25.215 describes the physical layer, 3GPP TS 25.331 describes the radio resource control protocol, and 3GPP TS 25.133 describes requirements for radio resource management, which are incorporated herein by reference in their entirety.
[0006] FIG. 1 illustrates the architecture of the radio access network that handles all radio-related functionality in Release '99. User Equipment (UE) 11 is connected via the radio interface to a respective first Node B 21 - 1 . First Node B 21 - 1 converts the data flow between the lub and radio interface and also participates to a limited extent in radio resource management. First Node B 21 - 1 and second Node B 21 - 2 are both connected to the same Radio Network Controller (RNC) 31 - 1 via the lub interface and share the same radio resource management. RNC 31 - 1 is responsible for the control of the radio resources in its domain, i.e. first node B 21 - 1 and second node B 21 - 2 . Although only two are shown in FIG. 1 , there will normally be more than two Node B's connected to a single RNC. Each group of Node B's and single RNC constitute a radio network subsystem (RNS) and although only two are shown in FIG. 1 , there will normally be a large number of RNS's in a radio access network. Collectively, the RNCs are the service access points for all services (including, for example, management of connections to UE 11 ) that the radio access network provides to a core network (not shown) via the lu interface. The elements shown in FIG. 1 are defined at the logical level, but may have a similar physical implementation as well.
[0007] In Release '99, there is little flexibility in scheduling the transmissions on the uplink from UE 11 to Node B 21 . The physical layer rate signaling terminates at Node B 21 . The RRC limits the TFCS using various signaling formats and UE 11 can only use the allowed TFCS. This has the disadvantage that various measurements and UE RRC reports taken to SRNC, processed and sent to UE 11 , all over a frame structure measured in milliseconds.
[0008] In Release '99, scheduling changes can be made in the uplink using the unacknowledged signaling mode in Radio Resource Control (RRC) with a specified activation time. Alternatively, the RRC includes the ability to control and limit the Transport Format Combination Control using various signaling formats. The transport format combination control can be sent in transparent mode on its own transport channel in every TTI. Transport format combinations can be indexed, with a list of allowed/non-allowed combinations or an full open set of combinations. For an example of the specifications, including the maximum of time that should pass after a signaling message is received due to processing in the UE before the new combination is assumed, see 3GPP TS 25.331 v 3.8.0, Section 13.5.
[0009] This method of using the RRC ability to limit the TFCS can be slow to adapt to changes in the network, such as in the amount of data to be transmitted between network elements. Also, since the method is dependent on RRC controlled by the RNC, it susceptible to processing bottlenecks and other factors affecting the performance of the RNC.
BRIEF SUMMARY
[0010] In a first aspect of the preferred embodiment of the invention, a wireless communications network comprises a plurality of terminals and at least one base station which transmits data to each one of said plurality of terminals on a wireless downlink and receives data from each one of said plurality of terminals on a wireless uplink. At least one of said plurality of terminals sends a rate request to said base station, said rate request requesting that the data rate on the wireless uplink be changed. Said base station, in response to said rate request from said at least one of said plurality of terminals, sends a rate grant to said at least one of said plurality of terminals, said rate grant indicating whether or not said at least one of said plurality of terminals may change the data rate on the wireless uplink.
[0011] In a second aspect of the preferred embodiments, the present invention provides a reliable data rate control method and wireless communications network including a radio access network which transmits data from a base station to a terminal in a wireless downlink and receives data from the terminal to the base station in a wireless uplink. In this aspect of the preferred embodiments of the invention, the terminal is adapted to receive two thresholds specifying the limits on the data rate on said wireless uplink, a first one of said two thresholds specifying a limit for said data rate that may be requested by said terminal and a second one of said two thresholds specifying a limit for said data rate that may be requested by said base station. The terminal sends a rate request on the wireless uplink from the terminal to the base station, said rate request requesting that the data rate on said wireless uplink be increased or decreased within the limits of said first one of said two thresholds. The terminal increases or decreases the data rate on said wireless uplink in accordance with said rate grant in response to a rate grant received from said base station, said rate grant indicating whether or not said data rate on said wireless uplink may be increased or decreased as requested in said rate request.
[0012] In another aspect of the preferred embodiments of the invention, the wireless communications network including a base station which transmits data to a terminal on a wireless downlink and receives data from a terminal on a wireless uplink carries out a method. The method comprises sending a rate request from said terminal to said base station, said rate request requesting that the data rate on the wireless uplink be increased or decreased; and in response to said rate request from said terminal, sending a rate grant to said terminal, said rate grant indicating whether or not said terminal may increase or decrease the data rate on the wireless uplink.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The preferred embodiments are described below with reference to the accompanying drawings, in which:
[0014] FIG. 1 is a block diagram illustrating the uplink connection of user equipment in a radio access network according to 3GPP Release '99.
[0015] FIG. 2 graphically illustrates an example of the two RRC controlled thresholds applied to the transport format combination set according to the preferred embodiments of the invention.
[0016] FIG. 3 graphically illustrates a data rate control concept utilized in the preferred embodiments of the invention.
[0017] FIG. 4 graphically illustrates an example of multiple user equipment rate control according to a preferred embodiment of the present invention.
[0018] Like reference numerals identify like parts throughout the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] The particulars shown herein are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention. The description taken with the drawings make it apparent to those skilled in the art how other various embodiments of the present invention may be implemented in practice.
[0020] Further, elements are shown in block diagram form in order to avoid obscuring the invention, and also in view of the fact that specifics with respect to implementation of such block diagram arrangements is highly dependent upon the network environment within which an embodiment of the present invention is to be implemented, i.e., specifics should be well within the purview of one skilled in the art. Although the preferred embodiments of the invention are described with reference to the example system block diagram of 3GPP Release '99 in FIG. 1 , embodiments of the invention may be practiced in other wireless communication networks, including but not limited to, subsequent 3GPP specification releases.
[0021] Where specific details (e.g., interfaces) are set forth in order to describe embodiments of the invention, it should be apparent to one skilled in the art that the invention can be practiced without these specific details. Finally, it should be apparent that any combination of hardware and software programming can be used to implement embodiments of the invention and that the embodiments are not limited to any specific combination of hardware and software programming.
[0022] As known to one skilled in the art, data is conventionally transmitted over the air interface in accordance with radio resource control signaling sent by a RNC over lub interface, which signaling includes configuration and reservation of radio resources. The Node B 21 performs L 1 air interface processing such as channel coding and interleaving, rate adaptation, spreading, etc. The term “rate adaptation” refers to rate matching in which the number of data bits to be transmitted is adapted to the number of bits available on a frame and does not refer to the present invention. See, for example, Section 6.4.2 of the book “WCDMA for UMTS (revised edition)” by Harri Holma and Antti Toskala, published by John Wiley & Sons, 2001 for further discussion of rate matching. It also performs some basic radio resource management functions such as inner loop power control. The RNC 31 terminates the RRC signaling protocol with UE 11 . It performs L 2 air interface processing of the data to/from the radio interface. Radio Resource Management functions, such as mapping of Radio Access Bearer (RAB) parameters into air interface transport channel parameters, handovers, and outer loop power control are executed in RNC 31 .
[0023] As described in further detail hereafter, the preferred embodiments of the invention have a two threshold rate control by which Node B 21 , being closer to the air interface than SRNC 31 , can perform limited but fast uplink scheduling operations. The two thresholds for two respective network elements allow fast and distributed scheduling of data on the uplink. The preferred embodiments of the invention are not limited to any particular signaling method for performing the scheduling over the air interface. An example of the uplink signaling method is provided in U.S. patent application Ser. No. 10/156,751, filed on May 24, 2002, entitled “Method and Apparatus for Distributed Signaling for Uplink Rate Control” and commonly assigned to Nokia Corporation, the assignee of this application, the contents of such application are hereby incorporated by reference in their entirety.
[0024] As a preferred embodiment of this invention, the two thresholds are set with reference to the combination sets utilized in the Transport Format Combination Control (TFCC). In 3GPP Release '99, transport format combination control is specified in 3GPP TS 25.331 v3.8.0 (2001-09), Section 8.2.5 and data rates correspond to various transport format combination sets. Specifically, in the preferred embodiments, RNC 31 specifies two transport format combination set (TFCS) thresholds. In addition to UE threshold 100 , a Node B threshold 200 is also specified. Both Node B 21 and UE 11 are informed of these thresholds. UE 11 is normally limited to UE threshold 100 , but may use the Node B threshold 200 as instructed by Node B 21 . There is no per se limitation on the value of UE threshold 100 and Node B threshold 200 . Indeed, either Node B threshold 200 or both thresholds may include the entire TFCS range.
[0025] FIG. 2 graphically depicts the TFCS thresholds. Separate RRC signaling between Node B 21 and UE 11 controls TFCS selection and utilization of the space above UE threshold 100 and below Node B threshold 200 . UE 11 can freely select its Transport Format Combination (TFC) from any of those in the set below the UE threshold 100 . Between the UE threshold 100 and Node B threshold 200 , Node B 21 can control the limitations given to UE 11 . Hence, Node B 21 can selectively schedule the uplink data rates of UE 11 .
[0026] UE 11 is aware of the entire range of possible data rates (TFCS) for the wireless uplink, such as, for example, from 16 kbps to 2 Mbps. The UE threshold 100 specifies the highest data rate that it can use (with appropriate signaling from RNC), such as, for example, 384 kbps. The Node B threshold 200 can be set at, for example, 2 MBps, and UE 11 can be required to send a rate request to Node B 21 for changes in the data rate above 384 kbps. This requirement may be made for all such changes (increase or decrease) or only for increases in the data rate. Node B 21 and UE 11 may receive only UE threshold 100 or both UE threshold 100 and Node B threshold 200 . In particular, Node B 21 may receive both thresholds, but UE 11 receives only UE threshold 100 .
[0027] FIG. 3 depicts the data rate control concept utilized in the preferred embodiments of the invention. The bottom portion of FIG. 3 indicates the value of rate requests sent by UE 11 , the value of the transport format combination as indicated by the TFCI value, and the data on the wireless uplink. The upper portion of FIG. 3 indicates the value of the rate grant signal sent by Node B in response to the rate request.
[0028] The sequence of events in the preferred method is as follows. First, UE 11 transmits its data along with a rate request (up or down). Node B 21 receives the data and the rate request (RR) from UE 11 . Then, Node B 21 sends a rate grant to UE 11 containing an indication of whether the UE 11 may increase, decrease or remain at the current data rate depending on the received interference conditions or other appropriate traffic metrics either derived/measured at Node B 21 and/or sent to Node B 21 from RRC. In one embodiment, UE 11 may be considered to have returned to the range of allowed data rates if it is using data rates below that specifed by UE threshold 100 (384 kbps in the above example). In such a case, a rate request to decrease the data rate on the wireless uplink would not ever be necessary.
[0029] Preferably, but not necessarily, the up/down rate request is included at every TTI period. Preferably, but not necessarily, the up/down/keep rate grant is provided at every TTI period. Alternatively, the rate request may be sent when a certain event occurs in UE 11 , such as, for example, when the transmit buffer of UE 11 exceeds a certain limit.
[0030] FIG. 4 demonstrates a scenario whereby multiple UEs using the two threshold concept are controlled by Node B 21 . In this example, Node B 21 controls the first UE's data rate (increasing) and the second UE's data rate (decreasing) at regular intervals. In particular, it slowly redistributes resources between each UE primarily connected to it under control of RNC 31 . The changes are gradual as allowed by RRM. A primary connection is established so that only one Node B in a network can control one UE.
[0031] These preferred embodiments of the invention provide termination closer to air interface than in conventional radio access network architectures. They also provide the advantage of faster processing on L 1 /L 2 between Node B 21 and UE 11 . This is because even though the time intervals are subject on any particular network implementation, the time intervals of communication frames between UE 11 and Node B 21 are typically measured in the tens of milliseconds. Thus the speed with which the data scheduling on the uplink can be adjusted in the space between UE threshold 100 and Node B threshold 200 is several orders of magnitude grater than that which can be achieved when the adjustments are dependent on the signaling from RNC 31 .
[0032] Signaling of the two thresholds to UE 11 is a trivial addition to the RRC protocol and the details thereof are not essential to the invention. One embodiment would be to add the Node B threshold 200 as an optional extra parameter or information element to the Transport Format Combination Control (TFCC) message in RRC signaling.
[0033] Likewise, signaling of the UE threshold 100 and Node B threshold 200 to to Node B 21 would be an extension of the Node B Application Protocol (NBAP) where the details are not essential. Of course, the notification of the two threshold to Node B 21 can be carried out in any number of different ways.
[0034] While the invention has been described in terms of its preferred embodiments, it should be understood that numerous modifications may be made thereto. It is intended that all such modifications fall within the scope of the appended claims.
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A wireless communications network has a plurality of terminals and at least one base station which transmits data to each one of said plurality of terminals on a wireless downlink and receives data from each one of said plurality of terminals on a wireless uplink. One of the terminals sends a rate request to the base station. The rate request requests that the data rate on the wireless uplink for the terminal be changed. In response to the rate request, the base station sends a rate grant to the terminal. The rate grant indicates whether or not the terminal may change the data rate on the wireless uplink.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a continuation-in-part application of Petitioner's earlier application Ser. No. 10/685,549 filed Oct. 14, 2003, entitled A DISPENSING SYSTEM which is a continuation-in-part application of Petitioner's earlier application Ser. No. 10/372,375 filed Feb. 22, 2003, entitled CLOSED LOOP DISPENSING SYSTEM, which is a continuation-in-part application of Petitioner's earlier application Ser. No. 10/074,469 filed Feb. 12, 2002, entitled CLOSED LOOP DISPENSING SYSTEM WITH METERING ORIFICE.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention disclosed in Petitioner's earlier application Ser. No. 10/685,549 filed Oct. 14, 2003, relates to a dispensing system, which may be either an open loop or closed loop dispensing system, and more particularly to a dispensing system for dispensing corrosive liquid chemicals or dangerous medical liquid products which are typically drawn from the upper end of a container, such as a bottle or the like, to a mixing machine or the like. In that invention, the container is inverted with the liquid product gravity flowing from the lower end thereof. Further, the dispensing system of that invention provides a means for venting the container during shipment or storage in those situations where the liquid within the container requires venting. In the instant invention, three dosing and/or dispensing embodiments are disclosed which are ideally suited for use with portions of the invention of Ser. No. 10/685,549 filed Oct. 14, 2003.
[0004] 2. Description of the Related Art
[0005] Corrosive liquid chemicals and dangerous medical liquid products are typically contained in a container such as a bottle or the like and are frequently dispensed therefrom to a mixing machine. Normally, a cap is placed on the bottle with a dip tube extending therefrom downwardly into the interior of the bottle for drawing the liquid upwardly thereinto. Normally, a dispensing tube extends from the cap to a mixing machine or some other piece of equipment which creates suction in the dispensing tube to draw the liquid from the interior of the bottle. In some prior art devices, when the suction or vacuum is removed from the dispensing tube, backflow may occur. Further, when the cap is removed from the bottle, backflow from the dispensing tube may also occur. Additionally, when the cap is removed from the bottle, liquid residue in the bottle may spill therefrom. Additionally, the conventional prior art systems normally do not prevent the re-use of the bottle which is prohibited in some cases. Yet another disadvantage of the prior art is that a reliable and efficient venting means for the bottle is not normally provided for relieving vacuum pressure from within the bottle. The system of co-pending application Ser. No. 10/372,375 solved the problems associated with the prior art devices or systems.
[0006] While the system of co-pending application Ser. No. 10/372,375 works extremely well when the container is in its normal upright condition, the system may not perfectly function when the container of the co-pending application is inverted. When the container or bottle of co-pending application Ser. No. 10/372,375 is inverted, the liquid in the container is drawn or discharged from the normal upper end of the container but which is the lower end of the container in the inverted position. In such a position, the venting membrane, which would normally permit ambient air to replace the liquid in the container as the liquid is discharged from the container, may become “clogged” due to the liquid coming into contact therewith and crystallizing thereon. If air is not permitted to enter the container as the liquid is drawn therefrom, a partial vacuum is created in the upper end of the inverted container which will interfere with the discharge of the liquid therefrom.
[0007] The system of co-pending application Ser. No. 10/372,375 solved the problems of the prior art and represented an improvement in the invention of co-pending application Ser. No. 10/074,469. The invention of application Ser. No. 10/685,549 filed Oct. 14, 2003, represents an improvement over the invention described in co-pending application Ser. No. 10/372,375. The instant invention represents an improvement over the invention described in co-pending application Ser. No. 10/685,549 filed Oct. 14, 2003.
SUMMARY OF THE INVENTION
[0008] This invention relates to a dispensing system for use with a container, such as a bottle or the like, having an outlet opening formed in the upper end thereof. A cap is removably mounted on the container for selectively closing the outlet opening during shipment and storage. In use, the container is positioned in an inverted position. The lower end of the inverted container has a hollow throat extending downwardly therefrom which has interior and exterior surfaces. A throat plug assembly, having upper and lower ends, is positioned in the throat of the container. The throat plug assembly includes a hollow cylindrical plug member having an open upper end, an open lower end, and a cylindrical wall portion extending therebetween. A tube support is positioned on the open upper end of the plug member. A hollow tube, having upper and lower ends, is secured to the tube support so that its lower end is positioned below the tube support within the plug member. The open lower end of the plug member defines a valve seat. A valve assembly or means is movably positioned within the plug member and includes a normally closed valve and a hollow valve stem extending upwardly therefrom. The hollow valve stem is slidably mounted on the hollow tube which is secured to the tube support. The valve is movable between open and closed positions. The valve, when in its closed position, seats upon the valve seat to close the open lower end of the plug member. A spring is provided in the plug member which is in engagement with the valve means to yieldably urge the valve to its closed position. The valve, when in its closed position, prevents liquid within the container from flowing therefrom. The valve, when in its open position, permits liquid within the container to flow therethrough. At least one of the tube support, cylindrical wall portion or valve stem has a passageway formed therein. The throat plug assembly, when the valve is in its open position, permits liquid in the container to flow therefrom through the passageway, around the valve and outwardly through the valve seat. The throat plug assembly, when the valve is in its open position, permits air to enter the container by passing through the valve seat, around the valve and through the passageway.
[0009] When the container contains liquids that require venting during storage or shipment, the throat plug assembly is designed in such a way so as to cooperate with the container cap so that the valve is slightly unseated so that pressure within the container may be vented through the throat plug assembly and through an opening formed in the cap. The valve permits vapor pressure to pass therethrough but prevents liquid from passing therethrough.
[0010] The instant invention involves three dosing and/or dispensing embodiments which may be used with portions of the invention described in application Ser. No. 10/685,549 filed Oct. 14, 2003, and illustrated in FIGS. 1 - 10 hereof. FIGS. 11 - 12 illustrate a lever operated, gravity flow control assembly which may be mounted on the reservoir of FIGS. 1 - 10 . FIGS. 13 - 14 illustrate an embodiment which may be mounted on the reservoir of FIGS. 1 - 10 . FIGS. 15 - 16 illustrate an embodiment including a modified form of the valve actuator.
[0011] It is therefore a principal object of the invention to provide an improved dispensing system for corrosive or dangerous liquids contained in a container such as a bottle or the like, when the container is positioned in an inverted condition.
[0012] A further object of the invention is to provide a dispensing system which includes a throat plug positioned in the outlet opening of the container with the throat plug being designed so that it will permit vapor pressure within the container to be vented therethrough when the container is being stored or transported.
[0013] Still another object of the invention is to provide an improved dispensing system of the type described which permits sufficient air to enter the interior of the container to replace the liquid being dispensed therefrom so that vapor locks are prevented.
[0014] Still another object of the invention is to provide a dispensing system which is safe and convenient to use.
[0015] Yet another object of the invention is to provide dosing and/or dispensing systems representing an improvement in the prior art.
[0016] Yet another object of the invention is to provide a dispensing system which is reliable in use.
[0017] These and other objects will be obvious to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] [0018]FIG. 1 is a perspective view of a container in an inverted position so as to dispense liquids;
[0019] [0019]FIG. 2 is a perspective view of a throat plug assembly illustrating the throat plug in the position when the container is inverted;
[0020] [0020]FIG. 3 is a perspective view of the throat plug assembly with the throat plug assembly being illustrated in the position when the container is in its upright condition;
[0021] [0021]FIG. 4 is an exploded perspective view of the throat plug assembly of FIG. 2;
[0022] [0022]FIG. 5 is a partial vertical sectional view of the container in an upright condition illustrating the manner in which the throat plug assembly and cap permit venting of vapor pressure within the container;
[0023] [0023]FIG. 6 is a partial exploded perspective view of the container and cap in an upright condition;
[0024] [0024]FIG. 7 is an exploded perspective view of one means of mounting the inverted container at a dispensing location;
[0025] [0025]FIG. 8 is an exploded perspective view illustrating an inverted container and its relationship to the structure of FIG. 7;
[0026] [0026]FIG. 9 is a vertical sectional view of the apparatus of FIG. 8;
[0027] [0027]FIG. 10 is a view similar to FIG. 9 except that the container has been mounted on the receptacle at the dispensing location;
[0028] [0028]FIG. 11 is a perspective view illustrating a lever operated, gravity flow control assembly for use with the reservoir of FIG. 7;
[0029] [0029]FIG. 12 is a vertical sectional view illustrating the assembly of FIG. 11 mounted on the reservoir of FIG. 7;
[0030] [0030]FIG. 13 is a perspective view of a manual dosing dispenser mounted on a reservoir;
[0031] [0031]FIG. 14 is a vertical sectional view of the dispenser of FIG. 13;
[0032] [0032]FIG. 15 is a perspective view of another dosing dispenser; and
[0033] [0033]FIG. 16 is a vertical sectional view of the dispenser of FIG. 15.
DETAILED DESCRIPTION OF THE INVENTION
[0034] FIGS. 1 - 10 illustrate the invention of the co-pending application Ser. No. 10/685,549 filed Oct. 14, 2003. The following description with respect to FIGS. 1 - 10 is found in the co-pending application and is repeated herein to complete the description of the instant claimed invention.
[0035] In FIGS. 1 - 10 , the numeral 10 refers to a conventional container such as a bottle or the like which is used for transporting, storing and dispensing liquids therefrom. FIG. 1 illustrates the container 10 in an inverted dispensing position. Container 10 includes a hollow throat portion 12 extending downwardly therefrom and which has external threads 14 mounted thereon.
[0036] The numeral 16 refers to a throat plug assembly which will be described as it is positioned when the container 10 is in the inverted position. The throat plug assembly 16 is inserted into the hollow throat portion 12 of the container 10 while the container 10 is in its upright position. For purposes of description, throat plug assembly 16 will be described as including an upper end 18 and a lower end 20 . The lower end 20 of the throat plug assembly 16 includes a hollow cylindrical plug member 22 having an open upper end 24 , an open lower end 26 , and a cylindrical wall portion 28 extending therebetween. A disk-like tube support 30 is detachably mounted on the upper end of the cylindrical wall portion 28 , preferably by means of a snap-fit connection. Tube support 30 includes a tube 32 having a lower end portion 34 and an upper end portion 36 . As seen in the drawings, lower end portion 34 extends downwardly from tube support 30 and upper end portion 36 extends upwardly from tube support 30 . In some cases, upper end portion 36 will not be needed. In some cases, a flexible tube (not shown) will be secured to the upper end of upper tube portion 36 so as to extend upwardly into the container 10 , if so required. As seen in FIG. 2, tube support 30 has a plurality of spaced-apart passageways 38 formed therein.
[0037] The lower end of the plug member 22 defines a centrally located opening which defines a valve seat 40 . The lower end of plug member 22 also has an outwardly extending lip portion 42 which is designed to engage the upper end of the container 10 , as seen in FIG. 5, to limit the downward movement of the throat plug assembly 16 with respect to container 10 when the throat plug assembly 16 is inserted downwardly into the container 10 while the container is in its upright position (FIG. 5).
[0038] The numeral 44 refers generally to a valve means which is movably positioned within the plug member 22 and which includes a normally closed valve 46 and a hollow valve stem 48 extending upwardly therefrom. Valve stem 48 includes one or more passageways 50 extending therethrough. Valve 46 includes a tapered portion 52 at it lower end which terminates in a lower end portion 54 . In those cases where the container contains liquids requiring venting during storage or shipment, the lower end portion 54 will protrude slightly downwardly from the lower end of plug member 22 , a illustrated in FIG. 9. Valve stem 48 slidably receives the lower end of lower end portion 34 of tube 32 , as illustrated in FIG. 9. Spring 56 embraces valve stem 48 and lower end portion 34 to yieldably urge valve 46 to its lower closed position.
[0039] FIGS. 7 - 9 illustrate portions of a dispensing station which is referred to generally by the reference numeral 58 . Dispensing station 58 may be located within a cabinet or simply upon a horizontally disposed board or shelf 60 having an opening 62 formed therein. Included at the dispensing station 58 is a upper fixture 64 which includes a flange 66 having screw or bolt openings 68 formed therein. The fixture 64 includes an upwardly extending internally threaded stub 70 . The interior of pipe stub 70 is provided with a plurality of longitudinally extending grooves or passageways formed therein. At the lower inner end of stub 70 are a plurality of support arms 74 which extend across the opening 76 and which have an actuator rod 78 secured thereto and extending upwardly therefrom.
[0040] A lower fixture 80 is positioned below the shelf and within the shelf 60 , as illustrated in FIGS. 7 and 9. Screws 82 secure the fixtures 64 and 80 together, as seen in FIG. 7. Preferably, the lower end of fixture 80 includes an externally threaded throat portion 84 for dispensing liquid therethrough to a on-off valve 86 or other dispensing or metering device.
[0041] When the container 10 is being used to store, transport or dispense liquids which require venting during the shipment or storage thereof, the container 10 will include a vented cap 88 having a vent opening 90 formed therein, the lower end of which is closed by a membrane 92 which permits air to pass therethrough but does not pass liquid to pass therethrough. When the cap 88 is screwed onto the container 10 , the membrane 92 will engage the end 54 of valve 46 to slightly open valve 46 , as illustrated in FIG. 5, to permit air to be vented from the bottle while preventing liquid from being discharged from the bottle. When valve 46 has been slightly unseated, as illustrated in FIG. 5, vapor pressure within the container 10 may pass through the passageways or openings 94 formed in cylindrical wall member 28 and thence through the opening between the tapered surface 52 of valve 46 and the valve seat 52 and thence through the membrane 92 outwardly through the opening 90 . When the throat plug assembly of this invention is not going to be used in situations where it is necessary to vent vapor pressure from the container during shipment or storage, there is no need for the end portion 54 of tapered portion 52 to be included. In that situation, the valve 46 will positively close the valve seat 40 . Regardless of whether the end portion 54 is utilized or not, when the cap 88 is removed from the container 10 , the valve 46 will close the valve seat 52 . The container 10 is then inverted with the external threads 14 of the container 10 being threadably engaged with the internal threads on the stub 70 . As the container 10 is threadably mounted into the fixture 64 , the actuator rod 78 engages the valve means 44 at 96 which will cause the valve 46 to unseat from the valve seat 52 . Although the fixture 64 is shown as including internal threads to effect the connection between the container and the fixture, a push-pull connection could also be utilized. Such a connection is commonly referred to as a snap-in connection.
[0042] When it is desired to dispense the liquid from the container 10 into a receptacle, tub, container, etc., the valve 86 is opened to permit liquid to flow through the passageways 94 , passageways 50 , and through the valve seat 52 , through the fixture 64 , through fixture 80 , and outwardly through the valve 86 . Air is permitted to enter the interior of the container 10 to prevent air locks therein during the dispensing of liquids by permitting ambient air to pass downwardly through the passageways 72 in stub 70 , thence through passageways 94 , passageways 50 , and upwardly through the passageway 36 and also through the tube 32 into the interior of the container. Although it is preferred that all of the passageways 50 , 94 and 38 be utilized, in some situations it may be only necessary to use the passageways 38 or it may only be necessary to utilize the passageways 94 or it may be only necessary to utilize the passageways 50 . If the liquid is very viscous, it may be advantageous to insert a flexible tube onto the upper end of upper end portion 36 so that air passing through the tube 32 will be able to pass through the viscous liquid to the upper end of the container.
[0043] Thus the dispensing system of FIGS. 1 - 10 may be utilized to vent containers or it may be used where venting is not required. The system of FIGS. 1 - 10 is extremely economical and provides for a continuous gravity flow due to the fact that ambient air can enter the interior of the container to replace the liquid being dispensed therefrom. The dispensing system of FIGS. 1 - 10 eliminates any possibility of a vapor lock and provides a positive shut-off.
[0044] [0044]FIGS. 11 and 12 illustrate a lever operated, gravity flow control assembly 100 which may be mounted on the reservoir 80 of FIGS. 1 - 10 . Assembly 100 includes a hollow, cup-shaped housing 102 including an internally threaded upper end 104 which is threadably secured to the lower end of the reservoir 80 . Housing 102 includes a cylindrical wall 106 which has an arcuate cam track 108 formed therein which has a lower end 110 and an upper end 112 . Housing 102 also includes a bottom wall 114 which has a central opening 116 formed therein.
[0045] The numeral 118 refers to a valve actuator assembly which is selectively vertically and rotatably mounted in housing 102 and which extends upwardly through reservoir 80 . Assembly 118 includes a disc-shaped member 120 which movably sealably engages the inside surface of wall 106 . A hollow tube 122 extends upwardly from member 120 and has one or more openings 124 formed in the wall surface thereof. The inner lower end of tube 122 is in fluid communication with tube 126 which extends downwardly from member 120 . Normally, a bottle or the like will be secured to tube 126 to facilitate the flow of liquid from the container into the bottle or the like. However, the tube 126 itself may be used to transfer the fluid into any suitable receptacle. Actuator stem 128 extends upwardly from the upper end of tube 122 through reservoir 80 for selective engagement with the valve 46 to open the same. Lever 130 is secured to the member 120 and extends outwardly through the cam track 108 . Preferably, the outer end of the lever 130 has a knob 132 mounted thereon.
[0046] When lever 130 is at the lower end 110 of the cam track 108 , the valve 46 is in its fully closed position (FIG. 12). To open valve 46 , the lever 130 is moved upwardly along the cam track 108 which causes the actuator stem 128 to move upwardly into engagement with the valve 46 to move the same upwardly to open the same. The lever 130 is selectively rotated to achieve the desired flow rate. When the lever 130 is at the lower end 110 of the cam track 108 , the container may be removed from the fixture to replace the same since the valve 46 is in its normally closed position of FIG. 12. The container may be screwed onto the fixture, snapped onto the fixture, or lever locked onto the fixture as desired.
[0047] FIGS. 13 - 14 illustrate an embodiment wherein structure is mounted on the reservoir 80 ′ to enable the apparatus to function as a manual dosing dispenser. In the embodiment of FIGS. 13 and 14, the reservoir 80 ′ will have a predetermined volume such as one ounce, two ounces, etc. The manual dosing structure is designated by the reference numeral 200 . Structure 200 includes an elongated valve actuator 202 which is selectively vertically movable within an opening 204 formed in the bottom of the reservoir. Actuator 202 includes a lower tubular portion 206 which is vertically movably received by the opening 204 and which has a laterally extending disc, flange, fingers, etc. referred to generally by the reference numeral 208 . Tubular portion 206 is hollow so as to define a passageway 210 extending therethrough. Spring 212 embraces tubular portion 206 between the bottom of reservoir 80 ′ and disc 208 to normally maintain tubular portion 206 in its lower “closed” position of FIG. 14. Tubular portion 206 is provided with one or more openings 214 formed therein which are sealed by the bottom wall of the reservoir 80 ′ when the tubular member is in its lower position (FIG. 14). Shoulder 216 is provided at the upper end of tubular portion 206 to limit the downward movement of the valve actuator 202 .
[0048] Valve actuator 202 includes a valve member 218 at the upper end of the tubular portion 220 , as seen in FIG. 14. Rod 222 is provided at the upper end of actuator 202 for engagement with the valve 46 . When the valve actuator 202 is in its lower position, as seen in FIG. 14, the upper end of rod 222 is preferably in engagement with valve 46 , to open the same, to enable liquid in the container to fill the dosing reservoir 80 ′. The liquid cannot drain from the reservoir at this time due to the fact that the opening(s) 214 are sealed.
[0049] Assuming that the reservoir 80 ′ is full with the predetermined volume of liquid and it is desired to dispense the same therefrom into a bottle or the like, the open upper end of the bottle is positioned so that the open lower end of tubular portion 206 is received thereby. Upward movement of the member 208 causes valve 218 to seal or close the lower end of valve seat 40 , thereby preventing additional liquid from the inverted container from passing downwardly into the reservoir 80 ′. At the same time, the liquid in the reservoir 80 ′ may flow therefrom through the opening(s) 214 into and through passageway 210 and into the bottle.
[0050] When the predetermined liquid dose has been discharged into the receiving bottle, the member 208 is lowered until shoulder 216 engages the bottom of reservoir 80 ′, which seals opening(s) 214 . At that time, liquid from the inverted container can then flow around valve 46 into the reservoir for the next dispensing sequence.
[0051] Another dosing dispenser embodiment is illustrated in FIGS. 15 and 16 and includes a valve actuator assembly referred to generally by the reference numeral 300 . Assembly 300 includes a cup-shaped cap 302 which is screwed onto the threads 84 o the reservoir 80 . Ring block 304 is positioned with cap 302 and has a central opening 306 formed therein which registers with the opening 308 in cap 302 . Hollow tubular member 310 is vertically movably received by openings 306 and 308 and has a shoulder or lift valve 312 provided therein which limits the downward movement of tubular member 310 with respect to ring block 304 . Tubular member 310 is provided with one or more openings 314 formed therein which are positioned within ring block 304 when the valve actuator is in its lower “closed” position of FIG. 16. Spring 316 embraces tubular member 310 between the bottom of reservoir 80 and a lift lever 318 secured to the lower end of tubular member 310 to yieldably urge the actuator to its lower position. Rod 320 extends upwardly from lift valve 312 and has its upper end positioned closely to the normally closed valve 46 when in the “closed” position of FIG. 16.
[0052] When it is desired to fill a bottle or the like with the liquid from the inverted container, the bottle is placed beneath the lift lever 318 and then raised so that rod 320 raises and unseats valve 46 to enable liquid from the container to flow around valve 46 , into reservoir 80 , through opening(s) 312 which are now exposed above ring block 304 , and downwardly through the passageway 322 into the bottle. The bottle is lowered and removed when the desired liquid level in the bottle has been received. As the bottle is lowered, the lift valve 312 seats upon ring block 304 to prevent further liquid from passing through opening 306 . Lowering of the lift lever 318 also causes valve 46 to again close.
[0053] Although the invention herein is ideally suited for use with a container mounted on a fixture, the invention herein may be associated with a container which is not mounted on a fixture but which is portable so that the container may be carried from one location to another for use at those locations.
[0054] Thus it can be seen that the invention accomplishes at least all of its stated objectives.
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A dosing and/or dispensing system for use with a liquid container such as a bottle or the like for dosing and/or dispensing liquid contents from the bottle. Three different dosing and/or dispensing embodiments are disclosed which enable the liquid to be dosed or dispensed by gravity from the container.
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BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates to DRAM (Dynamic Random Access Memory) cells, and more particularly, to DRAM cells with self-aligned gradient wells.
[0003] 2. Related Art
[0004] In a typical trench DRAM cell there exists a VPT (vertical parasitic transistor) that causes a leakage current during the normal operating of the DRAM cell. Therefore, there is a need for a structure and a method for forming the same of a DRAM cell in which the leakage current flowing through the VPT is reduced without compromising other device characteristics.
SUMMARY OF THE INVENTION
[0005] The present invention provides a semiconductor structure, comprising (a) a semiconductor substrate; (b) an electrically conducting region in the semiconductor substrate, wherein the electrically conducting region includes a first portion, a second portion, and a third portion, and wherein the second portion is on top of and electrically coupled to the first portion, and the third portion is on top of and electrically coupled to the second portion; (c) a first doped semiconductor region (i) in the semiconductor substrate, (ii) wrapping around side walls and a bottom wall of the first portion of the electrically conducting region, but (iii) electrically insulated from the electrically conducting region by a capacitor dielectric layer; and (d) a second doped semiconductor region (i) in the semiconductor substrate, (ii) wrapping around side walls of the second portion, but (iii) electrically insulated from the second portion by a collar dielectric layer, where in the second doped semiconductor region is self-aligned to the first doped semiconductor region, wherein the collar dielectric layer is in direct physical contact with the capacitor dielectric layer, and wherein when going from an interfacing surface of the collar dielectric layer and the second doped semiconductor region and away from the collar dielectric layer, a doping concentration of the second doped semiconductor region decreases.
[0006] The present invention also provides a semiconductor structure, comprising (a) a semiconductor substrate; (b) an electrically conducting region in the semiconductor substrate, wherein the electrically conducting region includes a first portion, a second portion, and a third portion, and wherein the second portion is on top of and electrically coupled to the first portion, and the third portion is on top of and electrically coupled to the second portion; (c) a first doped semiconductor region (i) in the semiconductor substrate, (ii) wrapping around side walls and a bottom wall of the first portion, but (iii) electrically insulated from the first portion by a capacitor dielectric layer; and (d) a second doped semiconductor region (i) in the semiconductor substrate, (ii) wrapping around side walls of the second portion, but (iii) electrically insulated from the second portion by a collar dielectric layer, wherein the second doped semiconductor region is self-aligned to the first doped semiconductor region, wherein the collar dielectric layer is in direct physical contact with the capacitor dielectric layer, wherein when going from an interfacing surface of the collar dielectric layer and the second doped semiconductor region and away from the collar dielectric layer, a doping concentration of the second doped semiconductor region decreases, wherein a thickness of the capacitor dielectric layer is less than a thickness of the collar dielectric layer, wherein the electrically conducting region comprises dopants having a first doping polarity, wherein the first doped semiconductor region comprises dopants having the first doping polarity, and wherein the second doped semiconductor region comprises dopants having a second doping polarity which is opposite to the first doping polarity.
[0007] The present invention provides a semiconductor fabrication method, comprising providing a semiconductor structure which includes (a) a semiconductor substrate, (b) a deep trench in the semiconductor substrate, wherein the deep trench comprises a side wall and a bottom wall, and wherein the side wall comprises an upper side wall portion and a lower side wall portion; forming a first doped semiconductor region and a second doped semiconductor region, wherein the first doped semiconductor region (i) wraps around the lower side wall portion of the deep trench and (ii) abuts the bottom wall and the lower side wall portion of the deep trench, wherein the second doped semiconductor region wraps around and abuts the upper side wall portion of the deep trench, wherein the second doped semiconductor region is self-aligned to the first doped semiconductor region, wherein the first doped semiconductor region comprises dopants of a first doping polarity, wherein the second doped semiconductor region comprises dopants of a second doping polarity which is opposite to the first doping polarity; and forming a dielectric layer and an electrically conducting region in the deep trench, wherein the dielectric layer is on the side wall and the bottom wall of the deep trench, wherein the dielectric layer comprises a capacitor dielectric portion and a collar dielectric portion, wherein the electrically conducting region comprises a first portion, a second portion, and a third portion, wherein the second portion is on top of and electrically coupled to the first portion, and the third portion is on top of and electrically coupled to the second portion, and wherein when going from an interfacing surface of the collar dielectric portion and the second doped semiconductor region and away from the collar dielectric portion, a doping concentration of the second doped semiconductor region decreases.
[0008] The present invention also provides a semiconductor fabrication method, comprising providing a semiconductor structure which includes (a) a semiconductor substrate, (b) an electrically conducting region in the semiconductor substrate, wherein the electrically conducting region includes a first portion, a second portion, and a third portion, and wherein the second portion is on top of and electrically coupled to the first portion, and the third portion is on top of and electrically coupled to the second portion, (c) a first doped semiconductor region (i) in the semiconductor substrate, (ii) wrapping around side walls and a bottom wall of the first portion, but (iii) electrically insulated from the first portion by a capacitor dielectric layer, and (d) a second doped semiconductor region (i) in the semiconductor substrate, (ii) wrapping around side walls of the second portion, but (iii) electrically insulated from the second portion by a collar dielectric layer, wherein the collar dielectric layer is in direct physical contact with the capacitor dielectric layer, and wherein when going from an interfacing surface of the collar dielectric layer and the second doped semiconductor region and away from the collar dielectric layer, a doping concentration of the second doped semiconductor region decreases
[0009] The present invention provides a DRAM cell (and a method for operating the same) with a gradient P-well self-aligned to the buried plate to reduce the leakage current through the VPT (vertical parasitic transistor).
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIGS. 1-25 show a first fabrication process of a DRAM cell with a self-aligned gradient P-well, in accordance with embodiments of the present invention.
[0011] FIGS. 26-30 show a second fabrication process of another DRAM cell with a self-aligned gradient P-well, in accordance with embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0012] FIGS. 1-25 show a first fabrication process for forming a DRAM (Dynamic Random Access Memory) cell structure 100 , in accordance with embodiments of the present invention.
[0013] More specifically, with reference to FIG. 1 , in one embodiment, the first fabrication process starts out with a semiconductor substrate 110 such as a lightly doped silicon substrate. Other suitable alternative types of substrates include germanium (Ge), silicon germanium (SiGe), silicon carbide (SiC), and those consisting essentially of one or more compound semiconductors such as gallium arsenic (GaAs), gallium nitride (GaN), and indium phosphoride (InP). Alternatively, the substrate has a semiconductor-on-insulator type structure, e.g., a silicon-on-insulator (SOI) substrate.
[0014] Next, in one embodiment, a pad oxide layer 120 is formed on top of the semiconductor substrate 110 by thermal oxidation. Alternatively, the pad oxide layer 120 can be formed by using a deposition technique such as CVD (Chemical Vapor Deposition) method.
[0015] Next, with reference to FIG. 2 , in one embodiment, a pad nitride layer 210 is formed on top of the structure 100 of FIG. 1 using CVD method.
[0016] Next, with reference to FIG. 3 , in one embodiment, a deep trench 310 is formed in the semiconductor substrate 110 . Illustratively, the deep trench 310 is formed by (i) depositing a hardmask layer such as boron-doped oxide (not shown) on top of the pad nitride layer 210 ( FIG. 2 ), (ii) patterning the deposited hardmask layer, pad nitride layer 210 , and pad oxide layer 120 , and (iii) etching the silicon substrate by a RIE (Reactive Ion Etching) process selective to the hardmask layer. The hardmask layer can be stripped after the deep trench 310 is formed or in any suitable later process steps.
[0017] Next, with reference to FIG. 4 , in one embodiment, a first dopant source layer 410 containing a first doping polarity is formed on top of the structure 100 of FIG. 3 including on side walls and on a bottom wall of the deep trench 310 ( FIG. 3 ). Illustratively, an ASG (arsenic silicate glass) layer 410 with a thickness 50-1000 angstroms is formed by CVD or ALD (atomic layer deposition) method as the dopant source for N-type dopants, resulting in the structure 100 of FIG. 4 . Alternatively, other materials such as oxide doped with phosphorus, antimony, or any combination of these dopants can be used as the dopant source for N-type dopants.
[0018] Next, with reference to FIG. 5 , in one embodiment, the deep trench 130 is filled with a sacrificial material 510 . Preferably, the sacrificial material 510 is a polymer such as a resist or SiLK®, the latter of which is available from Dow Chemical. Illustratively, the sacrificial material 510 is formed by a conventional coating technique.
[0019] Next, in one embodiment, a top portion 510 a of the sacrificial material 510 is recessed to a predetermined depth and a bottom portion 510 b of the sacrificial material 510 still remains as shown in FIG. 6 . A conventional RIE, CDE (chemical downstream etch), or other suitable process can be used for recessing the sacrificial material 510 . Hereafter, the bottom portion 510 b of the sacrificial material 510 is referred to as a sacrificial material region 510 b.
[0020] Next, with reference to FIG. 6 , in one embodiment, the exposed portion of the ASG layer 410 is removed by, illustratively, wet etching with an enchant containing hydrofluoric acid, resulting in the ASG region 410 ′ as shown in FIG. 7 .
[0021] Next, with reference to FIG. 7 , in one embodiment, the sacrificial material region 510 b , when it is a resist, is removed by, illustratively, wet etching with an enchant containing sulfuric acid and hydrogen peroxide, resulting in a trench 810 as shown in FIG. 8 . Alternatively, the sacrificial material region 510 b is removed by a dry etch process
[0022] Next, with reference to FIG. 9 , in one embodiment, a second dopant source layer 910 is formed on top of the structure 100 of FIG. 8 including side walls and a bottom wall of the trench 810 ( FIG. 8 ). Dopants in the second dopant source layer 910 have the opposite polarity to the doping polarity of dopants in the first dopant source layer 410 . Preferably, the dopant concentration in the second dopant source layer 910 is lower than the dopant concentration in the first dopant source layer 410 and the thickness of the second dopant source layer 910 is less than the thickness of the first dopant source layer 410 to facilitate the formation of self-aligned P-well and buried plate in later processes. Illustratively, a BSG (borosilicate glass) layer 910 with a thickness of 20-300 angstroms formed by CVD, ALD, or thermal deposition as the second dopant source layer. Alternatively, other suitable dopant source materials such as an oxide containing indium can be used.
[0023] Next, with reference to FIG. 10 , in one embodiment, a cap layer 1010 is formed on top of the structure 100 including on side walls and on a bottom wall of the trench 810 ( FIG. 9 ). Illustratively, the cap layer 1010 is formed by CVD or ALD of silicon dioxide (SiO 2 ).
[0024] Next, in one embodiment, the structure 100 of FIG. 10 is annealed at a high temperature (e.g., 700-1100° C.). As a result, arsenic dopants in the ASG region 410 ′ diffuse into the semiconductor substrate 110 , resulting in an N+ buried plate 1110 ; and boron dopants in the BSG layer 910 diffuse into the semiconductor substrate 110 , resulting in a gradient P-well 1120 which is self-aligned to the buried plate 1110 , as shown in FIG. 11 .
[0025] In one embodiment, the ASG layer 410 ′ underneath the BSG layer 910 has a thickness greater than 400 angstroms prevents boron diffusion into the buried plate region 1110 , resulting in only arsenic diffusion into the buried plate region 1110 .
[0026] In another embodiment, the buried plate 1110 comprises both N-type dopants (coming from the ASG region 410 ′) and P-type dopants (coming from the BSG layer 910 ). In one embodiment, in the buried plate 1110 , the doping concentration of the N-type dopants is greater than the doping concentration of the P-type dopants. In other words, it is said that the buried plate 1110 electrically exhibits the N-type doping polarity.
[0027] In one embodiment, the doping concentration of the ASG region 410 ′ is greater than the doping concentration of the BSG layer 910 .
[0028] In one embodiment, the doping concentration of N-type dopants in the buried plate 1110 ranges preferably from 10 18 to 10 20 /cm 3 and more preferably from 10 19 to 5×10 19 /cm 3 . The doping concentration of P-type dopants in the buried plate region 1110 , if present, is preferably less than 20%, and more preferably less than 10% of the doping concentration of N-type dopants. The doping concentration of P-type dopants in the gradient P-well 1120 ranges preferably from 10 17 to 5×10 19 /cm 3 and more preferably from 5×10 17 to 5×10 18 /cm 3 .
[0029] Next, with reference to FIG. 11 , in one embodiment, the cap layer 1010 , the BSG layer 910 , and the ASG region 410 ′ are removed by using wet etching with an etchant containing hydrofluoric acid, resulting in a trench 1210 as shown in FIG. 12 .
[0030] Next, with reference to FIG. 13 , in one embodiment, a capacitor dielectric layer 1310 is formed on top of the structure 100 of FIG. 12 including on side walls and on a bottom wall of the trench 1210 ( FIG. 12 ). Illustratively, the capacitor dielectric layer 1310 comprises silicon nitride. In one embodiment, the capacitor dielectric layer 1310 is formed by CVD of silicon nitride followed by a high temperature anneal (e.g., 800-1100° C.) in an environment containing oxygen. Alternatively, other suitable dielectric such as oxide, oxynitride, and/or “high-k” (high dielectric constant) materials.
[0031] Next, with reference to FIG. 14 , in one embodiment, a first conducting material (e.g., N+ polysilicon doped with arsenic, any metal such as tungsten, any conducting metallic compound such as tungsten silicide, or any other suitable conducting material) region 1410 is formed in the trench 1210 of FIG. 13 . Illustratively, the first N+ polysilicon region 1410 is formed by CVD of a polysilicon layer (not shown) everywhere on top of the structure 100 (including in the trench 1210 ) of FIG. 13 , and then (ii) optional planarization of the deposited polysilicon layer, e.g., by CMP (chemically mechanical polishing), until a top surface 1311 of the capacitor dielectric layer 1310 is exposed to the surrounding ambient as shown in FIG. 14 .
[0032] Next, in one embodiment, a top portion 1410 a of the first N+ polysilicon region 1410 is removed by, illustratively, RIE process, resulting in a bottom portion 1410 b of the first N+ polysilicon region 1410 , and resulting in a trench 1510 as shown in FIG. 15 . Hereafter the bottom portion 1410 b is referred to as a first N+ polysilicon region 1410 b.
[0033] Illustratively, with reference to FIG. 15 , a top surface 1411 of the first N+ polysilicon region 1410 b is essentially at a same level (i.e., coplanar) as a top surface 1115 of the N+ buried plate 1110 .
[0034] Next, in one embodiment, the exposed portion of the capacitor dielectric layer 1310 is removed by, illustratively, wet etching, resulting in a capacitor dielectric region 1310 ′ as shown in FIG. 16 .
[0035] Next, with reference to FIG. 17 , in one embodiment, a collar layer 1710 is formed on top of the structure 100 of FIG. 16 including on side walls and on a bottom wall of the trench 1510 . Illustratively, the collar layer 1710 comprises silicon oxide. In one embodiment, the collar layer 1710 is formed by thermal oxidation. In another embodiment, the collar layer 1710 is formed by a deposition technique such as CVD or ALD (atomic layer deposition). Yet in a third embodiment, the collar layer 1710 is formed by thermal oxidation followed by a deposition. A high temperature annealing process (e.g., 700-1100° C. for 2-200 minutes) may be performed, after the collar layer 1710 is formed by deposition, to densify the deposited collar layer 1710 and improve the integrity of trench structure. In one embodiment, the collar layer 1710 essentially contains no or substantially low dopant concentration for the reason that excessive dopants in the collar 1710 otherwise would diffuse into the p-well and into the trench and cause undesired dopant variation in these regions. It should be noted that a first thickness 1715 of the collar layer 1710 is equal or greater than a second thickness 1315 of the capacitor dielectric region 1310 ′.
[0036] Next, in one embodiment, a bottom portion 1713 and a portion 1714 of the collar layer 1710 are removed by, illustratively, RIE process such that the top surface 1411 of the first N+ polysilicon region 1410 and a top surface 213 of the pad nitride layer 210 are exposed to the surrounding ambient, and such that the collar layer 1710 still remains on the side walls of the trench 1510 , as shown in FIG. 18 .
[0037] Next, with reference to FIG. 19 , in one embodiment, a second conducting material (e.g., N+ polysilicon) region 1910 is formed in the trench 1510 of FIG. 18 . Illustratively, the second N+ polysilicon region 1910 is formed by (i) CVD of a polysilicon layer (not shown) everywhere on top of the structure 100 (including in the trench 1510 ) of FIG. 18 , and then (ii) optional planarization of the deposited polysilicon layer, e.g., by CMP, until the top surface 213 of the pad nitride layer 210 is exposed to the surrounding ambient, as shown in FIG. 19 .
[0038] Next, in one embodiment, a top portion 1910 a of the second N+ polysilicon region 1910 is removed by, illustratively, RIE process, resulting in a bottom portion 1910 b of the second N+ polysilicon region 1910 as shown in FIG. 20 . Hereafter, the bottom portion 1910 b is referred to as the second N+ polysilicon region 1910 b . In one embodiment, a top surface 1911 of the second N+ polysilicon region 1910 b is at a lower level than a top surface 115 of the semiconductor substrate 110 , as shown in FIG. 20 .
[0039] Next, with reference to FIG. 20 , in one embodiment, the exposed portion of the collar layer 1710 is removed by, illustratively, wet etching, resulting in a collar layer 1710 ′ and resulting in a trench 2010 as shown in FIG. 21 .
[0040] Next, with reference to FIG. 22 , in one embodiment, a third conducting material (e.g., N+ polysilicon) region 2210 is formed in the trench 2010 of FIG. 21 . Illustratively, the third N+ polysilicon region 2210 is formed by (i) CVD of a polysilicon layer (not shown) everywhere on top of the structure 100 (including the trench 2010 ) of FIG. 21 , (ii) optional planarization of the deposited polysilicon layer, e.g., by CMP, until the top surface 213 of the pad nitride layer 210 is exposed to the surrounding ambient; and then (iii) recess of the third N+ polysilicon region 2210 so that a top surface 2215 of the third N+ polysilicon region 2210 is at a same level with the top surface 115 of the semiconductor substrate 110 .
[0041] Next, in one embodiment, dopants of the third N+ polysilicon region 2210 diffuse into the semiconductor substrate 110 at subsequent high temperature (e.g., 700-1100° C.) processes, resulting in a buried strap region 2310 as shown in FIG. 23 .
[0042] Next, with reference to FIG. 24 , in one embodiment, an STI (shallow trench isolation) region 2410 is formed by conventional processes well known in the art. The pad nitride layer 210 and pad oxide layer 120 are removed before or after STI formation.
[0043] Next, with reference to FIG. 25 , in one embodiment, a gate dielectric layer 2520 , a gate electrode 2530 , a first source/drain region 2510 a , its associated contact region 2560 , and a second source/drain region 2510 b of an access transistor 2540 are formed by a conventional method, resulting in a DRAM cell which comprises a capacitor and the access transistor 2540 . It should be noted that the capacitor comprises a capacitor dielectric layer 1310 ′, a first capacitor electrode 1110 (which is the N+ buried plate 1110 ), a second capacitor electrode 1410 b + 1910 b + 2210 (which comprises the first N+ polysilicon region 1410 b , the second N+ polysilicon region 1910 b , and the third N+ polysilicon region 2210 ), and the buried strap region 2310 used to electrically connect the second capacitor electrode 1410 b + 1910 b + 2210 of the capacitor to the first source/drain region 2510 a of the access transistor 2540 .
[0044] It should be noted that there is an unwanted VPT (Vertical Parasitic Transistor) comprising a substrate, a gate electrode, a gate dielectric layer, a channel region, a first source/drain region and a second source/drain region. More specifically, the substrate of the VPT is the semiconductor substrate 110 , the gate electrode of the VPT is the second N+ polysilicon region 1910 b , the gate dielectric layer of the VPT is the collar layer 1710 ′, the channel region of the VPT is the gradient P-well 1120 , the first source/drain region of the VPT is the N+ buried plate 1110 , and the second source/drain region of the VPT is the buried strap region 2310 .
[0045] It should be noted that doping concentration of the P-well 1120 is gradient, meaning that when going from the collar layer 1710 ′ outward, the doping concentration of the gradient P-well 1120 decreases. It should also be noted that the P-well is self-aligned to the buried plate 1110 . The formation of the gradient P-well 1120 (the channel region of the VPT), which has the highest doping concentration next to the collar layer 1710 ′, effectively raises the threshold voltage of the VPT. The gradient P-well by this invention reduces the leakage current flowing through the VPT without significantly increasing junction current leakage through the junction between the N+ buried plate 1110 and the gradient P-well 1120 .
[0046] FIGS. 26-30 show a second fabrication process for forming a DRAM cell structure 200 , in accordance with embodiments of the present invention.
[0047] With reference to FIG. 26 , in one embodiment, the second fabrication process starts out with a structure 200 . Illustratively, the fabrication of the structure 200 of FIG. 26 is similar to the fabrication of the structure 100 of FIG. 15 . Preferably, the gradient P-well 1120 has a greater doping concentration in this embodiment than the first embodiment. Illustratively, the doping concentration in the gradient P-well 1120 is preferably ranges from 5×10 17 /cm 3 to 10 19 /cm 3 and more preferably ranges from 10 18 to 5×10 18 /cm 3 .
[0048] Next, in one embodiment, the exposed portion of the capacitor dielectric layer 1310 is removed by, illustratively, wet etching, resulting in the capacitor dielectric layer 1310 ″ as shown in FIG. 27 .
[0049] Next, with reference to FIG. 28 , in one embodiment, a second N+ polysilicon region 2810 is formed in the trench 1510 of FIG. 27 . Illustratively, the second N+ polysilicon region 2810 is formed by (i) CVD of a polysilicon layer (not shown) everywhere on top of the structure 200 (including in the trench 2610 ) of FIG. 27 , and then (ii) optional planarization of the deposited polysilicon layer, e.g., by CMP, until the top surface 211 of the pad nitride layer 210 is exposed to the surrounding ambient and then (iii) recess of the second N+ polysilicon region 2810 so that a top surface 2815 of the second N+ polysilicon region 2810 is at a same level with the top surface 115 of the semiconductor substrate 110 .
[0050] Next, in one embodiment, dopants of the second N+ polysilicon region 2810 diffuse into the semiconductor substrate 110 in the subsequent high temperature (e.g., 700-1100° C.) process, resulting in a buried strap region 2910 as shown in FIG. 29 .
[0051] Next, with reference to FIG. 30 , in one embodiment, an STI region 3040 is formed in the semiconductor substrate 110 by conventional processes well known in the art. The pad nitride layer 210 and pad oxide layer 120 are removed after STI formation.
[0052] Next, in one embodiment, a gate dielectric layer 3020 , a gate electrode 3030 , a first source/drain region 3010 a , its associated contact region 3060 , and a second source/drain region 3010 b of an access transistor 3050 are formed by a conventional method, resulting in a DRAM cell which comprises a capacitor and the access transistor 3050 . It should be noted that the capacitor comprises a capacitor dielectric layer 1310 ″, a first capacitor electrode 1110 (which is the N+ buried plate 1110 ), a second capacitor electrode 1410 b + 2810 (which comprises the first N+ polysilicon region 1410 b , and the second N+ polysilicon region 2810 ), and the buried strap region 2910 used to electrically connect the second capacitor electrode 1410 b + 2810 of the capacitor to the first source/drain region 3010 a of the access transistor 3050 .
[0053] Because of the gradient P-well 1120 which has the highest doping concentration next to the capacitor dielectric layer 1310 ″ and therefore effectively increases the threshold voltage of the VPT, the leakage current flowing through the VPT is significantly reduced without significantly increasing the junction leakage current. Furthermore, since the P-well 1120 in FIG. 30 has a greater doping concentration than the P-well in the first embodiment, the threshold voltage of the VPT is further increased. Consequently, a collar layer like the collar layer 1710 ′ in FIG. 25 (of the first fabrication process) can be eliminated. Besides, increasing too much the collar layer thickness is not applicable to trench technology with small ground-rules because the collar layer thickness is limited by the trench dimension.
[0054] In the embodiments described above, the doping polarities of the N+ buried plate 1110 , the first N+ polysilicon region 1410 b , the second N+ polysilicon region 1910 b , the third N+ polysilicon region 2210 , the buried strap region 2310 , the first and second source/drain region 2510 a , 2510 b , the second N+ polysilicon region 2810 , the buried strap region 2910 , and the first and second source/drain region 3010 a , 3010 b are N type whereas the doping polarity of the gradient P-well 1120 is P type. Alternatively, the doping polarities of the buried plate 1110 , the first polysilicon region 1410 b , the second polysilicon region 1910 b , the third polysilicon region 2210 , the buried strap region 2310 , the first and second source/drain region 2510 a , 2510 b , the second polysilicon region 2810 , the buried strap region 2910 , and the first and second source/drain region 3010 a , 3010 b can be P type whereas the doping polarity of the gradient well 1120 can be N type.
[0055] While particular embodiments of the present invention have been described herein for purposes of illustration, many modifications and changes will become apparent to those skilled in the art. Accordingly, the appended claims are intended to encompass all such modifications and changes as fall within the true spirit and scope of this invention.
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A DRAM cell with a self-aligned gradient P-well and a method for forming the same. The DRAM cell includes (a) a semiconductor substrate; (b) an electrically conducting region including a first portion, a second portion, and a third portion; (c) a first doped semiconductor region wrapping around the first portion, but electrically insulated from the first portion by a capacitor dielectric layer; (d) a second doped semiconductor region wrapping around the second portion, but electrically insulated from the second portion by a collar dielectric layer. The second portion is on top of and electrically coupled to the first portion, and the third portion is on top of and electrically coupled to the second portion. The collar dielectric layer is in direct physical contact with the capacitor dielectric layer. When going away from the collar dielectric layer, a doping concentration of the second doped semiconductor region decreases.
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FIELD OF THE INVENTION
The invention relates to belt guards for attachment to a casing of a clutch of a clutch motor for industrial sewing machines with a cover which at least partially encloses a V-belt pulley and which has an opening for ingoing and outgoing V-belt sections, and with a belt anti-drop device located within the cover, its radial distance from the axis of the V-belt pulley being adjustable, whereby the cover is divided along a plane parallel to the axis of the V-belt pulley and whereby two cover halves are connected to each other at the side of the cover opposite to the opening by a joint and are connected to each other adjacent to the opening in such a way that they can be pulled apart.
BACKGROUND OF THE INVENTION
A belt guard of this kind is described in German laid-open Patent Application No. 29 38 253. This belt guard does not exhibit ingoing belt safety devices which are required according to German Industrial Standards (DIN 42 703).
SUMMARY OF THE INVENTION
It is a main object of the invention to develop belt guards of the type outlined in such a way that an effective ingoing belt safety device is attained which can be adjusted to suit various diameters of V-belt pulleys and which allows the cover halves to be pulled apart without this movement being hindered by the safety device.
In accordance with the invention, this object is accomplished in a belt guard wherein an ingoing belt safety device is provided which comprises a safety pin extending into the wedge-shaped area between the ingoing belt section and the V-belt pulley, and wherein the safety pin is attached to a safety slide bar which is attached in its turn to the outer side of a cover half in such a way that it can be detached if required, and wherein the safety pin penetrates at least one opening in the cover half and can be adjusted within this opening.
In a second solution this object of the invention is accomplished in a belt guard wherein the cover halves can be fixed to a circular disc which is attached to the casing, and wherein an ingoing belt safety device is provided which comprises a safety pin extending into a wedge-shaped area between the ingoing belt section and the V-belt pulley, and wherein the safety pin is attached to the disc in an opening and can be adjusted within this opening.
Both solutions presented by the invention feature a safety pin which extends into the wedge-shaped area between the ingoing belt section on the one hand and the V-belt pulley on the other and which extends through and beyond the V-belt pulley. This safety pin can be adjusted in such a way that the maximum distance required by DIN 42 703 from the ingoing belt section on the one hand and from the V-belt pulley on the other can be maintained through simply shifting the safety pin and, if necessary, turning of the cover, whenever V-belt pulleys of various diameters are used. Both solutions presented by the invention allow the cover halves to be pulled apart without the ingoing belt safety device hindering this movement.
Additional advantages and features of the invention are set forth in the claims and in the following description of embodiments of belt guards in accordance with the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a frontal view of a belt guard corresponding to arrow I in FIGS. 2 and 3;
FIG. 2 is a top view of the guard corresponding to arrow II in FIGS. 1 and 3;
FIG. 3 is a side view corresponding to arrow III in FIGS. 1 and 2;
FIG. 4 is a vertical section of another embodiment of a belt guard corresponding to the intersection line IV--IV in FIG. 5; and
FIG. 5 is a top view of the belt guard according to the arrow V in FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
The belt guard shown in FIGS. 1 to 3 is designed to be fixed to a casing 1 of a clutch 2 of a clutch motor--not illustrated here--for use on industrial sewing machines. The casing 1 shows a ring flange 4 positioned concentrically to a shaft 3 coming from the casing 1. A V-belt pulley 5 is attached to the free end of the shaft 3 around which a V-belt 6 is guided with an angle of contact of approximately 250° to drive an industrial sewing machine.
The belt guard presented in FIGS. 1 to 3 comprises a cover 7 which encloses the V-belt pulley 5 with space between the two and an appropriate opening 8 for ingoing and outgoing V-belt sections 6 on the side where the V-belt enters and leaves the casing. The cover 7 has a mirror symmetric shape and is located congruent to the corresponding plane of symmetry of the V-belt 6. The cover 7 is divided along this plane of symmetry. The two cover halves 9, 10 closely meet along a dividing plane 11. They are connected by a joint 12 located on the opposite side to the opening 8, this joint allows the halves of cover 7 to be pulled apart as shown in the dot-dash representation in FIG. 1. The joint 12 is positioned parallel to the axis 13 of the shaft 3. The axis 13 is also situated in the dividing plane 11.
A circular disc 14 is fixed at the ring flange 4 of the casing 1 of the clutch 2 in a concentric and vertical position to the axis 13 by screws 15. A circular opening 16 has been made in the side of the cover 7 which faces the clutch 2. The diameter of this circular opening 16 is somewhat smaller than that of the disc 14. A ring groove 17 has been made in the margin area of this circular opening, the diameter and depth of which correspond to the diameter and thickness of the disc 14. When the cover halves 9, 10 are pulled apart they can be brought into a position in relation to the disc 14 so that the outer perimeter of the disc moves into the ring groove 17. If the cover 7 is closed by pushing the cover halves 9, 10 together, the outer perimeter of the disc 14 is encompassed by the ring groove 17, i.e. the cover 7 is fixed to the casing 1 of the clutch 2 and is immobile in the direction of the axis 13. The two cover halves 9, 10 have two plate elements 18 which are situated near the opening 8 on the side of the cover adjacent to the casing 1 on both sides of the dividing plane 11. The plate elements 18 are connected by a screw 19. By appropriate tightening of the screw 19 the cover halves 9, 10 can be braced against each other and thus against the disc 14 in such a way that they cannot be moved on this disc. By slightly loosening the screw 19 the cover 7 can be made to turn on the disc 14 so that an exact positioning of the cover 7 vis-a-vis the V-belt 6 is possible. The cover 7 will usually be positioned so that the ingoing belt section 20 of the V-belt 6 and the outgoing V-belt section run mirror-symmetrically to the dividing plane.
A belt anti-drop device 22 is attached to one cover half 10 on the side opposite to the opening 8 which is the side adjacent to the joint 12, i.e. opposite to the side where the belt enters and leaves. A slit 23 extending radially to the axis 13 has been made in the outer side 24 of the cover half 10 facing away from the casing 1. A catch 25 in the form of a pin or similar extending through and beyond the outer perimeter of the V-belt pulley 5 has been fixed here by an attachment screw 26. When the attachment screw 26 has been slightly loosened this catch 25 can be shifted in the longitudinal direction of the slit 23 so that for every conceivable V-belt pulley diameter or every conceivable position of the cover 7 on the casing 1 it can be positioned and fixed at the maximum distance required by DIN 42 703 of 3 mm to the outer perimeter of the V-belt pulley 5. As can be seen from FIG. 1 the belt anti-drop device 22 does not prevent the cover halves 9, 10 from being pulled apart.
An ingoing belt safety device 27 is provided in the cover half 10 accommodating the ingoing belt section 20 of the V-belt 6. This comprises a safety pin 28--a peg or similar--which extends into the wedge-shaped area between the ingoing belt section 20 of the V-belt 6 and the V-belt pulley 5, which is not encompassed by the V-belt 6 at this point, whereby the distance from the safety pin 28 to the perimeter of the V-belt pulley 5 on the one hand and to the ingoing belt section 20 on the other hand may not exceed a maximum of 4 mm according to DIN 42 703. This safety pin 28 running parallel to the axis 3 penetrates through the cover 7 to the same extent as the catch 25.
The safety pin 28 is secured to one of the safety slide bars 29 fixed to the outer side 24 of the cover half 10. The safety pin 28 passes through a slit 30 located in the outer side 24 into the inside of the cover 7. This slit 30 is positioned running at an angle α to the dividing plane 11 in such a way that the aforementioned stipulation on the distance from the safety pin 28 to the perimeter of the V-belt pulley 5 on the one hand and to the ingoing belt section 20 of the V-belt 6 on the other is observed given the differing diameters of the V-belt pulley. A further slit 31 can be located in the other cover half 9 mirror-symmetrically to this slit 30 so that the ingoing belt safety device 27 can be easily relocated if the direction of rotation changes. The angle α is approximately 35° to 50°.
The safety slide bar 29 itself has an elongated guide hole 32 through which a locking screw 33 is screwed in a threaded bore 34 in the outer side 24 of the corresponding cover half 10. In order to position the safety pin 28 as described, the locking screw 33 is slightly loosened so that the safety slide bar 29 can be shifted in the direction of its elongated guide hole 32 parallel to slid 30. Furthermore, the cover 7 can be turned slightly to achieve an exact positioning of the safety pin 28 relative to the ingoing V-belt section 20. If the cover 7 is to be removed from the casing 1 of the clutch 2, the locking screw 33 is completely loosened so that the safety slide bar parallel to the axis 13 can be removed, whereby the safety pin 28 comes out of its locking position between the ingoing V-belt section 20 and the disc 5. Finally, the two cover halves 9, 10 can be pulled apart.
A scale 35 has been placed on the outer side 24 parallel to slit 30 and 31 to which a marker 36 in the form of a pointer on the safety slide bar 29 has been assigned so that when the appropriate setting has been made on the scale 35 according to the diameter of the V-belt pulley 5 the correct position for the ingoing belt safety device 27 can be found without the necessity to first test and measure. The distance already described between the safety pin 28 and the ingoing V-belt section 20 is also set here by a final minimal turning of the cover 7.
Since the example according to FIGS. 4 and 5 differs from the example illustrated in FIGS. 1 to 3 in part only, the identical or at least similar and functionally identical parts are characterized by the same number together with an apostrophe ' so that the description must not be repeated.
The disc 14', which is also circular in this example, has arc-shaped elongated holes 41 positioned concentrically to the axis 13' to accommodate the screws 15' in order to allow the disc 14' to be turned and positioned around the axis 13'.
An ingoing belt safety device 27' is attached to the disc 14'. A slit 30' has been made in the disc 14' to accommodate this ingoing belt safety device 27'. For reasons which have already been shown another mirror-symmetrical slit 31' can be provided. There is a guide recess 42 in the side of the disc 14' facing the casing 1' for a threaded nut 43 which can be shifted in the guide recess 42 in the direction of the slit 30' (or 31' as the case may be) whilst remaining torsionally-rigid. A securing screw 44 is screwed into the threaded nut 43. This screw penetrates a sleeve-shaped safety pin 28' and is braced against the disc 14'. This safety pin 28' extends from the disc 14' into the wedge-shaped area between the ingoing V-belt section 20' and the V-belt pulley 5' at the maximum distances described above. It is possible to remove the cover 7' without loosening or removing the ingoing belt safety device. When the cover 7' is removed a simple positioning of the ingoing belt safety device is possible. This is effected by sliding the ingoing belt safety device in the slit 30' (or 31' as the case may be) whereby the disc 14' can be simultaneously turned as required. The position of the cover 7' is not effected by this.
A belt anti-drop device 22' is attached to the disc 14' on the side opposite to the ingoing and outgoing V-belt sections 20', 21'. The construction of this belt anti-drop device 22' is identical to that of the ingoing belt safety device 27'. The catch 25' is formed by a sleeve-shaped element which is screwed into a threaded nut 43 which is not shown separately in the diagram by a securing screw 26'. The corresponding slit 23' runs radially to the axis 13'.
There is an appropriate recess 45' in the ring flange 4' so that the disc 14' can be turned and positioned whilst both the belt anti-drop device 22' and the ingoing belt safety device 27' are in place.
In the two examples not only straight but also arched slits 30, 31 and 30', 31' respectively are possible in order to be able to satisfy as exactly as possible the above-described requirement for maximum distances from the safety pin 28, 28' to the V-belt pulley 5, 5' on the one hand and the ingoing V-belt section 20, 20' on the other.
In particular in the examples shown in FIGS. 4 and 5, the respective slit 23' or 30', 31' can be replaced by a series of adjacent holes so that the positioning of the belt anti-drop device 22' or the ingoing belt safety device 27' can be graduated. In this case, the respective hole can be designed as a threaded bore so that the guide recess 42 and the threaded nut 43 are rendered superfluous, i.e. the safety screw 44 or 26' can be screwed directly into the appropriate threaded bore. In the same way it is possible to replace slit 23 in the example shown in FIGS. 1 to 3 by a series of holes which accommodate the catch 25.
Similarly, the elongated guide hole 32 in the safety slide bar 29 as shown in the example in FIG. 1 to 3 can be replaced by a series of holes of this kind which then accommodate the locking screw 33.
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A belt guard for clutch motors for industrial sewing machines comprises a cover made of two cover halves which can be clapped together. This cover extensively covers a V-belt pulley part of which accommodates a V-belt. In order to achieve an effective ingoing belt safety device which can be adapted to suit a variety of V-belt pulley diameters without exceeding the permissible maximum distances to the ingoing V-belt section on the one hand and to the V-belt pulley on the other the ingoing belt safety device comprises a safety pin extending into the wedge-shaped area between the ingoing V-belt section and the V-belt pulley. This pin can be attached to a safety slide bar fixed to a cover half in an adjustable manner, or to a disc serving as a mount for the cover halves.
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[0001] This application claims the benefit of U.S. Provisional Application No. 61/178,100, filed May 14, 2009, which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention is generally directed to test model abstraction, and more particularly to domain engineering testing in product line engineering.
BACKGROUND
[0003] Many products, such as software, are released as part of a product line or in multiple variants of the product. Typically, the various products of a product line or the product variants include certain portions of design and engineering that are reused in each product and product variant. However, good industrial practice requires that each product and variant thereof be tested and verified as meeting the design requirements. Verification processes typically result in largely redundant testing because the re-used or common portions of the product line are retested for each product or variant.
[0004] Accordingly, improvements in product line engineering and testing product line engineering would be desirable.
SUMMARY OF THE INVENTION
[0005] In accordance with one aspect of the present invention, a system and method for product line engineering testing is provided. More specifically, a workflow diagram associated with the product line engineering is segmented to identify a variable activity areas. A stub activity is generated for the variable activity area and substituted into the workflow in place of the variable activity area.
[0006] In accordance with a further aspect of the present invention, the stub activity can be configured to generate valid output for the variable activities of the variable activity area. Furthermore, the stub activity can replace multiple variable activities and can be further configured to generate valid output for each of the variable activities replaced. Stub activities can be used for black-box, gray-box, and white-box testing.
[0007] In yet a further aspect of the present invention, a workflow decision node can be generated to isolate the segmented variable area. The generated workflow decision node can then be inserted into the workflow diagram prior to the segmented variable activities. Segmented variable activities can include decision nodes, such that the stub activity is substituted for the decision node.
[0008] These and other advantages of the invention will be apparent to those of ordinary skill in the art by reference to the following detailed description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a flowchart of a process in accordance with an embodiment of the present invention;
[0010] FIG. 2 is a workflow diagram in accordance with an embodiment of the present invention;
[0011] FIG. 3 is a further workflow diagram in accordance with an embodiment of the present invention;
[0012] FIG. 4 is a further workflow diagram in accordance with an embodiment of the present invention; and
[0013] FIG. 5 is a high-level block level diagram of a computing device in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
[0014] Software Product line engineering (SPLE) can be used to develop similar products in a cost effective manner with increased quality and reduced time to market. One focus of SPLE is the development of reusable parts or software artifacts (i.e., domain artifacts), which can be used within multiple versions of a product line. Thus, the development process for SPLE is divided into two processes: Domain Engineering for reusable elements and Application Engineering for application specific elements.
[0015] As the number of domain artifacts increases, the number of test artifacts increases combinatorially. At an application level, testing is costly because of redundancies in testing all common features for each variant of the software product. Furthermore, at the application level, testing errors that are discovered during testing are more costly to correct. Therefore, testing is preferably performed as much as possible during domain engineering in order to reduce effort and save cost. However, since changes in domain engineering, application engineering, and variability result in changes to the various test cases, it is preferable that only one test model be used for test case generation. Thus, in accordance with an embodiment of the present invention, the test artifacts can be organized to allow for efficient testing of applications derived from the domain artifacts. Specifically, various levels of abstraction can be used to allow for testing in domain engineering as well as application engineering.
[0016] FIG. 1 is a flowchart of a process 100 in accordance with an embodiment of the present invention. Process 100 operates on a variable workflow model that identifies the commonalities and variabilities (e.g., inclusion or exclusion of features and/or software artifacts) of a product line. Use cases are used to develop a requirements model, which is transformed into the variable workflow model. Such a model captures the constraints between different variation points, for example by including one feature, but excluding another, from a product. The variability information is captured using variation points. Identification of variable transitions can be accomplished, for example, by the system and methods disclosed in U.S. Provisional Application No. 61/175,529, which is incorporated herein by reference. Process 100 is described below with respect to the variable workflow models illustrated in FIGS. 2 , 3 , and 4 .
[0017] FIG. 2 illustrates an exemplary variable workflow model, in which variation points are represented as shaded decision points. More specifically, FIG. 2 illustrates a workflow 200 , having Activity- 1 210 , Activity- 2 220 , and Activity- 3 230 . As illustrated, these activities lead to Variation Point 280 from which the workflow may test Activity- 4 240 , Activity- 5 250 , Activity- 6 260 , or Activity- 7 270 . Activity- 6 260 and Activity- 7 270 are variable activities (illustrated as rhomboid) and are not included in all software variants. Accordingly, variation point 280 has a mixture of common outgoing edges (illustrated as sold lines) and variable outgoing edges (illustrated as broken lines). Specifically, edges 245 and 255 leading to Activity- 4 240 and Activity- 5 250 are common to all software variants. However, edges 265 and 275 are variable, similar to Activity- 6 260 and Activity- 7 270 , and are not included in all software variants.
[0018] Thus, once the variable transitions and activities have been identified, at step 110 the variable activities can be segmented from the workflow. The segmentation of the identified variable activities is shown in FIG. 3 , which illustrates a variable workflow 300 , similar to workflow 200 . Specifically, as illustrated in workflow 300 , variable activities Activity- 6 260 and Activity- 7 270 along with transition edges 265 and 275 and Variation point 280 are segmented (e.g., wrapped) by boundary 310 .
[0019] Because variation point 280 has a mixture of common and variable outgoing edges, variable edges 265 and 275 leading respectively to Activity- 6 260 and Activity- 7 270 cannot be isolated from workflow 300 . Thus, variation point 280 must be wrapped and segmented along with edges 265 and 275 , Activity- 6 260 , and Activity- 7 270 . Accordingly, at step 120 of process 100 , a new workflow is generated to by-pass the variable activities of the workflow.
[0020] The variable activities may include a variation point (e.g., variation point 280 ), in which case, generation of the new work flow can include generation of a decision point (i.e., FIG. 4 , decision point 420 ). Decision point 420 is inserted into the workflow prior to the variable activities. The generation of decision point 420 and insertion into the workflow is illustrated in workflow 400 of FIG. 4 . Workflow 400 is a transformation of workflow 300 after step 120 of process 100 . It should be noted that insertion of decision point 420 results in the variable area being an isolated variable area 410 . That is, all edges leading from decision point 280 (e.g., edges 245 , 255 , and 285 ) are common edges and therefore included in domain testing.
[0021] As illustrated in workflow 500 of FIG. 5 , the isolated variable area 410 illustrated in workflow 400 can be replaced by a stub activity 510 that simulates certain behaviors for domain testing purposes. Thus, at step 130 of process 100 , a stub activity 510 is generated for the segmented variable activities. The stub activity 510 can be configured to generate valid output for the variable activities (e.g., Activity- 6 260 and Activity- 7 270 ) of the isolated variable area 410 .
[0022] Specifically, because stub-activity 510 is being substituted for two activities (e.g., Activity- 6 260 and Activity- 7 270 ) the stub activity 510 can generate output in two ranges: a first range corresponding to the range of valid output for Activity- 6 260 , and a second range corresponding to the range of valid output for Activity- 7 270 . Accordingly, as illustrated, a single incoming edge 515 leads to stub activity 510 . However, two edges 511 and 512 are illustrated as outgoing from stub activity 510 . Each outgoing edge 511 and 512 represents a range of valid output. For example, edge 511 can represent the valid output of Activity- 6 260 , which was replaced by stub activity 510 , and edge 512 can represent the valid output of Activity- 7 270 , which was also replaced by stub activity 510 . If additional activities were replaced by stub activity 510 , additional outgoing edges representing the appropriate range of valid output can be included in workflow 500 as outgoing from stub-activity 510 .
[0023] Stub activity 510 can be configured in a variety of ways to increase testability and control domain level testing. For example, stub-activity 510 can be configured for black-box, white-box, or gray box testing. Further configurations generate random output within the valid range of output. Alternatively, the stub activity can generate output based on a script of output, which can itself be generated manually or by tracelogs captured from previous software runs (e.g., using previous iterations of software artifacts).
[0024] By abstracting the variability from the workflow test model, significant savings, in both time and cost, can be realized. Another benefit is that the commonalities between variants become testable even if they are within workflow paths that contain variable activities. Typically, commonalities are only tested in totally separated paths that contain no variable activities. Thus, paths through the workflow that are common to all software variants do not need to be retested with development of each application variant. Rather, the application testing can focus only on those use cases through the workflow that require variable activities.
[0025] The above-described methods for domain engineering testing in product line engineering can be implemented on a computer using well-known computer processors, memory units, storage devices, computer software, and other components. A high-level block diagram of such a computing device is illustrated in FIG. 6 . Computer 600 contains a processor 610 which controls the overall operation of the computer 600 by executing computer program instructions which define such operations. The computer program instructions may be stored in a storage device 620 , or other computer readable medium (e.g., magnetic disk, CD ROM, etc.), and loaded into memory 630 when execution of the computer program instructions is desired. Thus, the method steps of FIG. 1 can be defined by the computer program instructions stored in the memory 630 and/or storage 620 and controlled by the processor 610 executing the computer program instructions. For example, the computer program instructions can be implemented as computer executable code programmed by one skilled in the art to perform an algorithm defined by the method steps of FIG. 1 . Accordingly, by executing the computer program instructions, the processor 510 executes an algorithm defined by the method steps of FIG. 1 . The computer 600 also includes one or more network interfaces 640 for communicating with other devices via a network. The computer 600 also includes input/output devices 650 that enable user interaction with the computer 600 (e.g., display, keyboard, mouse, speakers, buttons, etc.) One skilled in the art will recognize that an implementation of an actual computer could contain other components as well, and that FIG. 6 is a high level representation of some of the components of such a computer for illustrative purposes.
[0026] The foregoing Detailed Description is to be understood as being in every respect illustrative and exemplary, but not restrictive, and the scope of the invention disclosed herein is not to be determined from the Detailed Description, but rather from the claims as interpreted according to the full breadth permitted by the patent laws. It is to be understood that the embodiments shown and described herein are only illustrative of the principles of the present invention and that various modifications may be implemented by those skilled in the art without departing from the scope and spirit of the invention. Those skilled in the art could implement various other feature combinations without departing from the scope and spirit of the invention. The various functional modules that are shown are for illustrative purposes only, and may be combined, rearranged and/or otherwise modified.
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Product line engineering testing is provided by segmenting a workflow into variable and common activity areas. A workflow decision node can be generated to isolate the segmented variable area, and a stub activity is generated and substituted into the workflow in place of the segmented variable activities. The stub activity can be configured to generate valid output for the substituted variable activities, and can be configured for black-box, gray-box, and white-box behavior.
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BACKGROUND OF THE INVENTION
This invention relates to a plasma surface treatment method and apparatus for treating a film surface by using plasma with a high efficiency.
There are known techniques for reforming the surface of a substrate made of various materials by making gas in a plasma state act on the surface. For example, for polymers, as discussed in an article entitled "Plasma niyoru Kobunshi Zairyo no Hyomen Shori (Surface Treatment of polymer materials by using plasma)" (Kogyo Zairyo (Industrial Materials), Vol. 32, p.24-30 (1982)), various kinds of applications are conceived, such as techniques, by which hydrophilic radicals are introduced in the surface by making oxygen plasma act thereon in order to improve the adhesivity of paints, plasma etching techniques using ion energy and reactions of active radicals, etc.
If it were possible to effect continuously such a plasma surface treatment on a long film, productivity thereof would be considerably increased. For this reason a continuous plasma surface treating apparatus has been proposed, as disclosed e.g. in JP-A-57-18737.
Also, as known apparatuses similar thereto, there are known continuous plasma surface treating devices disclosed in JP-A-59-91128 and JP-A-59-91130. In these kinds of apparatuses film is rolled on a rotating cylindrical treating drum disposed in a vacuum chamber and continuous plasma surface treatment for the film is effected by supplying electric power to a counter electrode disposed adjacent the side surface of the treating drum to produce plasma, while forwarding the film in one direction in synchronism with the rotation of the treating drum.
In this case, in order to increase the efficiency of the plasma surface treatment, conditions of the atmosphere for projecting high energy ions to the film are necessary. However, according to the prior art techniques described above, the treating drum is grounded and the potential difference between the treated surface and the plasma is at most only several tens of volts, even if a high frequency voltage of 13.56 MHz, which is a commercial frequency, is applied to the counter electrode to produce plasma. If the treating drum is not grounded and a negative high voltage is applied thereto, positive ions in the plasma are accelerated and in this way it is possible to increase the efficiency of the plasma surface treatment by using this energy. However, in the case where a high voltage is applied to the rotating treating drum, it gives rise to problems that (1) the mechanism becomes complicated, because a high voltage is applied to a rotating body, that (2) there is a fear that unnecessary discharge is produced, because parts other than the treated portion of the rotating drum are raised to the high voltage and that ( 3) when a metal film is disposed on the film, the metal film itself should be raised to the high voltage, and for this reason the feeding and rewinding mechanism is also raised to the high voltage, which complicates the insulating scheme therefor.
SUMMARY OF THE INVENTION
An object of this invention is to provide a plasma surface treatment apparatus permitting the treatment of a film by using plasma with a high treatment speed and a high efficiency without complicating uselessly the construction of the apparatus.
In order to achieve the object, according to one aspect of the present invention, in a plasma surface treatment apparatus in which film is wound on a grounded rotating electrode or rolling electrode and forwarded in one fixed direction, and gas introduced between the rotating electrode and a counter electrode disposed in a facing relationship adjacent the rotating electrode is transformed into a plasma by applying a high frequency voltage to the counter electrode, the area where the plasma is in contact with the counter electrode is made much larger than the area where the plasma is in contact with the rotating electrode.
It is known that, in the case where the effective areas of the electrodes are considerably different in a high frequency plasma, whose frequency is 100 kHz-100 MHz, the electrode having a smaller effective area becomes negative with respect to the other, i.e. the so-called self bias effect is produced. The effective area means here the area where one electrode is in contact with the plasma. Consequently, if a counter electrode having an area sufficiently larger than the area of the treatment portion of the rotating electrode, i.e. area where the electrode is in contact with the plasma is used and high frequency electric power is supplied to the counter electrode, the treatment portion of the grounded rotating electrode is raised to a negative high potential with respect to the potential of the plasma by the self bias effect. Since positive ions are accelerated by this potential difference and projected to the surface of the film, the treatment efficiency is increased considerably.
Here the concept "counter electrode having an area sufficiently larger than the area of the treatment portion of the rotating electrode" is explained more quantitatively. It is first assumed that the area where the plasma is in contact with the treatment drum is represented by S 1 and the area where the plasma is in contact with the counter electrode by S 2 . When the value of S 2 /S 1 is equal to 1, the potential differences between the plasma and the two areas are equal to each other. On the other hand, when S 2 /S 1 >1, the potential difference between the plasma and the treatment portion is greater than the other. This effect is realized, even if S 2 /S 1 is slightly greater than 1. However, the potential difference between the plasma and the treatment portion is greater and the treatment efficiency is increased with increasing S 2 /S 1 . Therefore, in order to obtain a satisfactory effect in the surface reformation treatment, it is preferable that S 2 /S 1 is greater than 1.5. Further, in the case where it is required for ions to have higher energy, such as for sputter etching, etc., it is preferable that S 2 /S 1 is greater than 3. In addition, gas used for the plasma treatment can be selected arbitrarily, depending on the purpose of the treatment. Further, the gas pressure can be selected so as to be suitable for the purpose of the treatment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a scheme illustrating the construction of a continuous plasma surface treatment apparatus according to this invention;
FIG. 2 shows a specific example of the construction at the neighborhood of the continuous plasma surface treatment apparatus according to this invention;
FIG. 3 shows another embodiment of the continuous plasma surface treatment apparatus according to this invention;
FIG. 4 is a scheme illustrating the construction of the continuous plasma surface treatment apparatus for explaining another example of the form of the counter electrode according to this invention;
FIG. 5 is a perspective view illustrating a specific construction at the neighborhood of the counter electrode indicated in FIG. 4;
FIG. 6 is a graph showing the relation between the etching speed of a polyester film and the electrode area ratio; and
FIG. 7 is a scheme illustrating the construction of a prior art continuous plasma surface device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinbelow this invention will be explained, referring to FIGS. 1 to 6.
FIG. 1 illustrates schematically the construction of a continuous plasma surface treatment apparatus according to this invention, in which the apparatus consists of a vacuum chamber 1, an evacuation mechanism 2 for evacuating it, a film forwarding mechanism 7-10, a plasma surface treatment chamber 3, a high frequency voltage applying mechanism 4, and a reactive gas supplier 5. The film forwarding mechanism is constituted by a forwarding roll for forwarding a film 6, a rotating electrode 8, a rewinding roll 9, a guide roll 10 for stabilizing the tension of the film and preventing the generation of wrinkles, a driving mechanism for rotating and regulating them, and a rotation speed regulating mechanism. In the plasma surface treatment chamber 3 are disposed a counter electrode 11, a gas inlet 12 and an evacuation port 13, as indicated in the figure. In order to introduce gas uniformly into the treatment chamber 3, it is desirable to form a number of small holes 14 in the counter electrode 11, as indicated in FIG. 2, through which the gas is blown out. Further, it is preferable to cool the rotating electrode 8 and the counter electrode 11 with water in order to prevent the temperature rise thereof due to heat produced by the plasma.
The counter electrode 11 in this embodiment is constructed so as to enclose the plasma, as indicated in FIG. 2, so that the plasma is not spread to the outer periphery portion of the rotating electrode 8. In this way the area where the plasma is in contact with the counter electrode 11 is larger than the area where the plasma is in contact with the rotating electrode 8. Meanwhile, as indicated in FIG. 7, in a prior art device, since the counter electrode 11 is disposed simply along the outer periphery of the rotating electrode 8 with a constant distance therefrom and thus the plasma is spread to the outer periphery portion of the rotating electrode 8, the effect of this invention cannot be obtained. However, the form of the counter electrode 11 according to this invention is not restricted to that indicated in FIG. 1.
FIGS. 4 and 5 indicate another form of the counter electrode. It differs from that indicated in FIG. 1 in that the portion of the counter electrode, which is closest to the rotating electrode, is formed along the outer periphery of the rotating electrode. It is obvious from the explanation above that the effect of this invention can be obtained equally well with the form of the electrode indicated in FIG. 4.
In this case the rotating electrode 8 as well as the vacuum chamber 1 are grounded and further the area of the counter electrode is sufficiently larger than the area where the plasma is in contact with the rotating electrode 8. Now, the plasma surface treatment method utilizing the plasma surface treatment apparatus according to this invention will be explained below for the case where the plasma surface treatment is effected as a preliminary step for depositing metal on a polyester film by evaporation as an example. This step is for the purpose of increasing the adhesive strength between the metal and the polyester film by forming unevenness by etching the surface of the polyester film with an Ar plasma or by introducing polar radicals therein.
A polyester film was set in the continuous plasma surface treatment apparatus indicated in FIG. 1 and Ar gas was supplied with a constant flow rate after having evacuated the reaction chamber in vacuum. At this time the flow rate and the evacuation speed were so regulated that the gas pressure in the reaction chamber was kept at about 13.3 Pa. Then, while driving the film forwarding mechanism and rewinding the film in a determined direction, a high frequency voltage having a frequency of 13.56 MHz and an amplitude of 1 kV was applied to the counter electrode to produce plasma. The treatment effect was studied, while varying the film forwarding speed, and a satisfactory adhesive strength was obtained even with a speed of 100 m/min.
Next, a carbon film formation method utilizing the same apparatus as mentioned above will be explained below.
In this embodiment the rotating electrode 8 is grounded and a high frequency voltage of 100 kHz to 100 MHz is applied to the counter electrode 11 disposed against it. In this way a plasma of hydrocarbon gas or a mixed gas of hydrocarbon and hydrogen is produced and a carbon film is formed on the surface of a film disposed on the grounded electrode (rotating electrode 8). One of the most important features of this invention is that the area of the counter electrode 11 is sufficiently larger than the area of the treatment portion of the rotating electrode 8 (grounded electrode). In the high frequency discharge of the frequency range described above the sheath voltage drop produced by the fact that the electron mobility is considerably greater than the positive ion mobility varies depending on the ratio of the effective areas of the two electrodes and the voltage drop is great for the electrode having a small area. Here, the effective areas mean areas, where the electrodes are in contact with the plasma. Consequently, the potential of the plasma is high with respect to the potential of the surface, when the area where the counter electrode 11 is in contact with the plasma is sufficiently larger than the area of the treated portion of the rotating electrode 8 (grounded electrode), which establishes a state where high energy ions are projected to the surface of the treated portion and a hard carbon film is formed thereon.
It is desirable that the ratio of the effective areas of the treated portion of the rotating electrode 8 (grounded electrode) and the counter electrode 11 described above is at least 1:3, more preferably 1:5. In addition it is desirable that the amplitude of the high frequency voltage is greater than 1 kV.
As the hydrocarbon stated above e.g. the following gases or vapors can be used:
1) saturated aliphatic hydrocarbons such as methane, ethane, propane, butane, etc.
2) unsaturated aliphatic hydrocarbons such as ethylene, acetylene, propene, butene, butadiene, etc.
3) aromatic hydrocarbons such as benzene, naphthalene, toluene, ethylbenzene, etc.
The hard carbon film formed by this embodiment is an amorphous carbon film, in which amorphous or crystalline parts containing hydrogen atoms are mixed and which is hard and hardly worn away, having a Vickers hardness of 1000 or greater.
Now, the method for forming a hard carbon film according to this invention will be explained below more in detail, taking the case where it is applied to the step for forming a protective film for a magnetic tape by evaporation as an example.
A polyester film 10 μm thick, on one side surface of which a Co/Ni alloy magnetic thin film 0.1 μm thick was deposited by evaporation, was set in the apparatus indicated in FIG. 1. Then benzene vapor was introduced into the vacuum chamber 1 and the treatment chamber 3, after having preliminary evacuated them to a pressure not greater than 1×10 -3 Pa, with a constant flow rate, so that the pressure in the treatment chamber 3 was kept at 6.66 Pa, while regulating the evacuation speed. After that, a high frequency voltage having a frequency of 13.56 MHz and a voltage amplitude of 2 kV was applied to the counter electrode 11 to produce plasma. After a treatment continuously effected during 3 hours a hard carbon film uniformly 20 nm thick was formed on the whole surface of the film 900 m long. During the treatment no abnormal discharge was found. The magnetic tape thus treated was slitted to form a band 8 mm wide and used in a reproduction device for VTR. Neither tape sticking nor tape drive instabilization happened and the life of the tape was remarkably elongated with respect to that without treatment.
For comparison a device, in which the counter electrode had an area smaller than that of the treated portion, as indicated in FIG. 7, was used and a plasma surface treatment was effected under the conditions, which were otherwise identical to those described above. In this way no satisfactory adhesive strength was obtained with the film forwarding speeds not less than 10 m/min. In order to know the effect stated above more quantitatively, the film was made to stand still in the devices indicated in FIGS. 1 and 7, in which plasma was produced during a predetermined period of time, and it was found that the etching speed in the device indicated in FIG. 1 is about 10 to 20 times as high as that obtained in the device indicated in FIG. 7.
In this connection, FIG. 6 shows the relation between the etching speed and the electrode area ratio, when a polyester film is etched by using the continuous plasma surface treatment device according to this invention.
The embodiment as described above can be also used with a high efficiency for electric charge preventive treatment for introducing polar radicals into films, plasma CVD, by which thin films are formed by reactive gas, plasma polymerization, etc. and it can be applied easily to these processes. Further, the above embodiment relates to the formation of a metal film on a polymer film. However, it is possible also to treat a polymer film coated with metal or metal foil in the same way.
FIG. 3 illustrates another embodiment, in which a plurality of treatment chambers are disposed against a rotating drum in order to increase the treatment speed. With this type of device, it is possible to form a multi-layered film by varying treatment conditions and/or the kind of reactive gas for every treatment chamber or to effect other treatments such as plasma cleaning, etching, sputtering, evaporation, etc. at the same time as the formation of the carbon film by varying the structure of specified treatment chambers. In the case where the high voltage is applied to the rotating electrode 8, the device cannot have the multiple functions as described above. Consequently these multi-functional characteristics are an auxiliary effect of this invention owing to the fact that the rotating electrode 8 is grounded.
As explained above, according to this invention, advantageous effects can be obtained that it is possible to treat films by using plasma with a high treatment speed and a high efficiency.
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A surface treatment method and apparatus permitting the treatment of a film with plasma with a high treatment speed and a high efficiency without uselessly complicating the construction of a device for realizing it are disclosed. The area where the counter electrode is in contact with the plasma is sufficiently larger than the area where the rotating electrode is in contact therewith. The ratio of the areas is preferably not smaller than 1.5 and the etching speed may be increased to a value more than ten times as great as that obtained by a prior art method.
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SUMMARY OF THE INVENTION
The present invention relates to an improvement in the process of deep tank cultivation of Bordetella pertussis of U.S. Pat. Nos. 3,577,319 and 4,429,046, the teachings of which are incorporated herein by reference. More particularly, it concerns a process involving a combination of biphasic and liquid growth. The initial subcultures are conducted on biphasic blood agar. The organisms from this biphasic blood agar growth are transferred to a secondary biphasic culture consisting of Cohen-Wheeler (CW) or Stainer-Scholte (SS) liquid medium. After suitable growth, the liquid portion is used to inoculate Modified CW or Modified SS liquid medium containing an anion exchange resin such as Dowex® 1-X8 or the like and an effective quantity of β-lactoglobulin in a larger vessel such as, for example, a 5-gallon vessel. After suitable growth, this liquid culture is used to innoculate Modified CW or Modified SS liquid medium containing anion exchange resin and β-lactoglobulin as hereinabove described in a larger, deep tank containing, for example, 125 gallons. After suitable growth in the tank, the organisms are killed, separated from the broth, and then suspended in buffered saline to produce the final vaccine. The supernatant may be saved for preparation of an acellular vaccine. This last step in the tank is the same as in the process formerly used.
Also, as in the former process, the operations are carried out as aseptically as possible. That is to say, the operations are aseptic as far as contamination with other organisms in concerned. As a result of the biphasic culturing and the incorporationn of purity checks, production yields are maximized.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The incubated agars are inoculated and the organisms are grown at about 35°-37° C. Microscopic examination and purity checks follow all subculturing. The blood agar flasks containing 100 ml of Bordet-Gengou Agar plus 15-25% sheep or rabbit blood are overlaid with 25 ml of Modified CW medium having the following composition:
______________________________________INGREDIENT GRAMS/LITER______________________________________Casamino Acids 10Sodium Chloride 2.5Potassium Phosphate Monobasic 0.5Magnesium Chloride 0.1Soluble Starch 1.5Calcium Chloride 0.01Ferrous Sulfate 0.01Copper Sulfate 0.005Glutathione 0.025Yeast Extract Dialyzate 75Distilled Water qs 1000 ml______________________________________
or 25 ml of Modified SS medium having the following composition:
______________________________________INGREDIENT GRAMS/LITER______________________________________L-proline 0.24Monosodium L-glutamate 10.7Sodium Chloride 2.5Potassium Chloride 0.2Potassium Phosphate Monobasic 0.5Magnesium Chloride 0.1Calcium Chloride 0.02Tris HCl Buffer, pH 7.6 0.05 --M 1.5Niacin 0.004Glutathione 0.1Ascorbic Acid 0.02L-Cystine 0.04Ferrous Sulfate.7H.sub.2 O 0.01Distilled Water qs 1000 ml______________________________________
The flasks are inoculated with 1-2 ml of cell suspension stock stored in liquid nitrogen, incubated at 35°-37° C. and continuously shaken at 60-80 strokes per minute. The incubation lasts for about 20-30 hours. Storage of the B. pertussis seed cells at liquid nitrogen temperatures are important to the results obtained.
The broth from the blood agar culture (2-5%) is transferred to a 5 liter toxin bottle containing 500 ml of CW charcoal agar overlaid with 200 ml of Modified CW medium, incubated at 35°-37° C. and continuously shaken at 60-80 strokes per minute. The incubation lasts for about 20-30 hours.
The broth from the CW charcoal culture (2-5%) is transferred to a bottle containing 3 liters of Modified CW or Modified SS medium with 3 g of Dowex® 1-X8 resin or the like and with between 0.5 mg/ml and 6.0 mg/ml of β-lactoglobulin. This culture is incubated at 35°-37° C., while continuously being shaken at 60-80 strokes per minute. The incubation lasts for about 20-30 hours. The culture is used to innoculate a fermentation tank.
A fermentation tank containing approximately 300 liters of distilled water is sanitized for a minimum of one hour at 120°-123° C. Once cooled, it is drained, charged with 400 g of Dowex® 1-X8 resin or the like, and 400 liters of the Modified CW or Modified SS medium is pumped into the tank and sterilized for 15-35 minutes at 120°-123° C. The tank is cooled to 32°-38°C. and held overnight under 10 lbs sterile air pressure. A sterile filtered solution of β-lactoglobulin is added to the tank medium to arrive at a final concentration of 0.5-6.0 mg/ml.
The culture from the liquid medium is inoculated into the fermentation tank and allowed to grow for about 20-48 hours at 32-38° C. with agitation and with approximately 3 cubic feet/minute of surface aeration.
After completion of fermentation, the tank is inactivated with a solution of sodium ethylmercurithiosalicylate to a final concentration of 0.01-0.02%. The contents of the vessel are cooled to about 20° C. and centrifuged at 15,000 rpm. The packed bacterial cells are collected and suspended in phosphate buffered saline, 0.85% solution containing 0.01% sodium ethylmercurithiosalicylate (thimerosol). The suspension is detoxified by allowing it to stand at 20°-25° C. for 2-10 days. Then, the stock is stored at 4° C. The supernatant, containing biologically active components, may be used for preparation of an acellular vaccine.
The main aspect of the present invention is concerned with a modification in the deep tank culture procedure which involves the addition of a substance such as β-lactoglobulin or the like, to a culture medium as described in U.S. Pat. No. 4,429,046 or to Modified SS medium as described herein. The addition of β-lactoglobulin has a significant effect on growth enhancement, antigen production and the vaccinal quality of the bacterium.
The culture method described in the above procedure, which includes the presence of β-lactoglobulin, is used to prepare a vaccine containing the hemagglutinating (HA) and lymohocytosis promoting (LPA) activities of B. pertussis. Hemagglutinin and lymphocytosis promoting factors are important components of the vaccine. The growth, hemagglutinin and lymphocytosis promoting activities of B. pertussis were greatly enhanced when the culture was prepared and tested as described below.
EXAMPLE 1
B. pertussis cells, grown on Bordet-Genou blood medium, were inoculated into 25 ml of Modified CW medium in a 500 ml flask and incubated in a water bath at 35° C. and 100 strokes per minute for 24 hours to prepare a seed culture. A 10% sterile filtered solution of β-lactoglobulin was added to 500 ml flasks containing 100 ml of Modified CW medium and 0.1 g of Dowex® 1-X8 ion-exchange resin at a final concentration of either 0, 0.1, 0.2, 0.4 or 0.6 mg/ml. Each flask was inoculated with the seed to arrive at a final seed cencentration of 2 opacity units/ml as determined by comparing the opacity of the culture to a reference standard comprising plastic beads which was obtained from the U.S. Food and Drug Administration and which is specifically provided for such purpose. The flasks were then incubated at 35° C. and 100 strokes per minute.
Samples were removed from each flask at 24 hours and 48 hours and examined for opacity (OPU), determined as described above, and hemagglutinating (HA) and lyphocytosis promoting activities in the supernatant (LPA), determined according to techniques well known to those skilled in the art. The results of these examinations are shown in Table I.
TABLE I______________________________________Enhanced Growth and Production of Hemagglutinating andLymphocytosis Promoting Activities in B. pertussisCulture Supernatant Due to β-lactoglobulinAmount ofβ-lacto-globulinadded OPU/ml HA* (U/ml) LPA** (U/ml)(mg/ml) 24 hrs. 48 hrs. 24 hrs. 48 hrs. 24 hrs. 48 hrs.______________________________________0 23 23 2.sup.1 0.sup. 11 830.5 32 26 2.sup.3 2.sup.2 100 1351.0 32 26 2.sup.4 2.sup.2 88 1152.0 34 27 2.sup.4-5 2.sup.4-5 88 934.0 32 29 2.sup.4-5 2.sup.4 70 936.0 33 27 2.sup.4 2.sup.4 70 100______________________________________ *Fresh goose red blood cells, 0.5% in saline, were used. **Enzymelinked immunosorbent assay (ELISA) with human haptoglobin was used.
Another procedure which discloses the beneficial aspects of adding β-lactoglobulin to a culture medium for B. pertussis is described in Example 2 below.
EXAMPLE 2
Two Woulfe bottles, each containing three liters of Modified CW medium with 0.3 g ion-exchange resin (Dowex® 1-X8), were inoculated with a seed suspension of B. pertussis prepared as described in Example 1. A sterile filtered solution of β-lactoglobulin was added to one bottle at a final concentration of 1.0 mg/ml. Each bottle was incubated at 35° C. and shaken on a reciprocating shaker at 60 strokes per minute. Samples were removed at 24 and 48 hours. To assay for mouse potency*, culture samples were diluted to 20 OPU/ml for testing. Additional samples were centrifuged at 10,000 rpm for 30 minutes. The supernatants were saved for analysis of hemagglutinating activity. The data in Table II show that the addition of β-lactoglobulin to the culture medium significantly improves mouse potency and production of HA.
TABLE II______________________________________Improved Production of HemagglutinatingActivity and Mouse Potency* inB. pertussis CultureAmount of Mouse Potency*β-lactoglobulin HA (U/ml) @ 20 OPU/mladded (mg/ml) 24 hrs. 48 hrs. (U/TID)**______________________________________0 2.sup.4 2.sup.2 441 2.sup.5 2.sup.5 94______________________________________ *According to the U.S. Code of Federal Regulations, 21 CFR 620.4 (a). **Units per total immunizing dose.
Still another test was performed to corroborate the findings in Tables I and II. In this procedure a comparison was made between two different media, as described in Example 3.
EXAMPLE 3
Five hundred ml flasks, containing 100 ml of either Modified CW or Modified SS medium and 0.1 g ion-exchange resin (Dowex® 1-X8), received a final concentration of 0 or 1.0 mg/ml β-lactoglobulin. Each flask was inoculated with a seed suspension B. pertussis prepared as noted in Example 1. The flasks were incubated at 35° C., 100 strokes per minute in a reciprocating water bath. Samples were removed at 24 and 48 hours and examined for opacity. Hemagglutinating and lymphocytosis promoting activities in the supernatant were assayed. In Table III, the results show that addition of β-lactoglobulin to either medium improved growth and the production of HA and LPA.
TABLE III__________________________________________________________________________Enhanced Growth and Production of Hemagglutinating and LymphocytosisPromoting Activities in B. pertussis Supernatant Usingβ-lactoglobulin and Different Mediaβ-lactoglobulin OPU/ml HA (U/ml) LPA (U/ml)Media Concentration (mg/ml) 24 hrs. 48 hrs. 24 hrs. 48 hrs. 24 hrs. 48 hrs.__________________________________________________________________________CW 0 29 23 2.sup.1-2 2.sup.1 22 46CW 1.0 31 27 2.sup.4 2.sup.1-2 68 98SS 0 26 33 2.sup.2-3 2.sup.1 69 75SS 1.0 31 36 2.sup.4-5 2.sup.3 108 221__________________________________________________________________________
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A Bordetella pertussis vaccine is prepared by deep tank cultivation using a seed grown in a biphasic culture system. An anion exchange resin in combination with β-lactoglobulin and a Modified Cohen-Wheeler or Modified Stainer-Schlolte medium is used in the process resulting in enhancement of the growth, antigen production and potency of the phase I Bordetella pertussis vaccine. An acellular Bordetella pertussis vaccine derived from the culture broth and cells of Bordetella pertussis useful in preparing an acellular vaccine and which are grown in a medium containing β-lactoglobulin and an anion exchange resin is also disclosed.
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FIELD OF THE INVENTION
This invention pertains to a safety gate mounted in a doorway, and is of great value in protecting of babies, by not allowing them through doorways in which the gate is mounted. This invention can be identified as "doorway safety gate apparatus".
PRIOR ART PERTAINING TO THIS INVENTION
U.S. Pat. No. 139,232 to Boughton for "Nursery Gates"--This patent discloses an expandable gate which locks on one end.
U.S. Pat. No. 141,677 to Tuttle for "Nursery Gates"--This discloses two frames A and B joined together--gates locks on the gate end.
U.S. Pat. No. 4,492,263 to Gebhard for "Infant Security Door Gate Assembly". This gate is an assembly of two segments, expandable by sliding on telescoping rods.
UK Pat. No. 2,041,051 to Adams for "Baby Gates". This is for an adjustable width gate, hinged on one end and locking on the opposite end.
Other reference patents of record are: U.S. Pat. No. 942,502, French No. 1,236,542, U.S. Pat. Nos. 2,662,242, 4,465,262, and 4,566,222.
None of the above cited prior patents touch the invention disclosed in this application.
OBJECTS OF THE INVENTION
One of the objects of this invention is to disclose a doorway safety gate, mounted on a removable frame, adjustable to fit in any width doorway, said doorway safety gate comprised of two halves each of which is mounted on a removable frame such that the gate halves meet or overlap in the middle of the doorway, and the two halves then locked together.
Another object of this invention is to disclose a doorway safety gate, comprised of two halves, each half mounted on hinges on opposite sides of a removable frame, adjustable to fit in a door frame, and the gate halves overlap on closing the gates segments.
Another object of this invention is to disclose a doorway safety gate comprised of two halves, which meet or overlap when the gate is closed.
Another object of this invention is to disclose a doorway safety gate comprised of two gate halves, said gate halves mounted on opposite sides of an adjustable removable frame, to fit in various door frame widths by means of hinges consisting of downward pointing fingers or pins on edges of said gate halves, said fingers or pins fitting in pin bearing sockets mounted on vertical legs of said removable frame.
Another object of this invention is to disclose a doorway safety gate comprised of two halves, the gate halves mounted on opposite sides of a removable frame adjustable to fit in variable width door frames, the gate halves mounted on the frame by hinges of downward pointing finger pins attached to a vertical side of each gate half and said downward pointing finger pins fitting in pin bearing sockets mounted on vertical legs of the removable frame.
Another object of this invention is to disclose a doorway safety gate comprised of two halves, the gate halves mounted on opposite sides of a removable frame adjustable to fit in variable width door frames the gate halves mounted on the frame by hinges of downward pointing finger pins attached to a vertical side of each gate half and said downward pointing finger pins fitting in pin bearing sockets mounted on vertical legs of the removable frame.
Another object of this invention is to disclose an adjustable removable frame comprising two L shaped sections, the bases of the L shaped sections to have mounted thereon pin bearing sockets, said pin bearing sockets to accommodate gate hinge sections comprising downward pointing finger pins attached to the gate edge sections.
Another object of this invention is to disclose a doorway safety gate apparatus wherein the invention consists of gate segments mounted on hinges on gate vertical frame mounts and the gate vertical frame mounts are attached to doorway frame by means of fastening screws.
DESCRIPTION OF DRAWINGS
FIG. 1. Showing safety guard gate components in front elevation view.
1. Doorway frame pillar
2. Gate vertical frame mounts
3. Doorway threshold
4. Vertical mount upper anchors
5. Gate half (segment)
5' Gate half (segment)
7,7' Threshold legs of gate vertical frame mounts
8. Hinge pin sockets
9. Hinge pins
15. Slots in gate center bar segment for inserting gate locking pin
20,20' Gate sag bumper
22,22' Center bar of gate segment
FIG. 2. Expanded view of frame of safety gate mount.
2. Gate vertical frame mounts
4. Vertical mount upper anchors
7,7' Threshold legs of gate vertical frame mounts
8. Hinge pin sockets
10. Hinge pin socket mount plate
11. Slot for vertical mount upper anchors
12. Fastening screw for threshold segments
13. Locking bolt for vertical mount anchor straps
26. Doorframe threshold
FIG. 3. Expanded end elevation view of fitting of threshold of safety gate mount wherein: (This is section AA of FIG. 2)
7,7' Threshold legs of gate vertical frame mounts
12. Fastening screw for threshold segments
26. Doorway frame threshold
FIG. 4. Front elevation of gate halves or segments (shown in expanded view) wherein:
5. Gate half or segment
5' Gate half or segment
9. Hinge pins
15. Slots in gate center bar segment for inserting gate locking pin
20. Gate sag bumper
22,22' Center bars of gate segment
24. Gate locking pin
FIG. 5. Enlarged elevation view of hinge pins fitting in hinge pin sockets wherein:
5. Gate half or segment
8. Hinge pin socket
9. Hinge pin
10. Hinge pin socket mount plate
16. Hinge pin key
17. Ghost lines of hinge pin leg groove keyway slot
FIG. 6. Enlarged plan view of hinge pin socket wherein:
8. Hinge pin socket
10. Hinge pin socket mount plate
17. Hinge pin groove keyway slot
FIG. 7. Enlarged elevation view of gate lock wherein:
5,5' Gate segments
14. Gate locking pin center section
15. Slots in the gate center bar segment for inserting gate locking pin
18. Gate locking pin flat head
22,22' Center bar of gate segment
FIG. 8. Enlarged plan view of gate lock (Section B--B of FIG. 7):
5,5' Gate segments
15. Slots in gate center bar segment for inserting gate locking pin
18. Gate locking pin head
24. Gate locking pin
29. Gate locking pin round head
FIG. 9. Enlarged plan view of gate locking pin wherein:
14. Gate locking pin center section
18. Gate locking pin flat head
21. Stop washer bearing
23. Gate locking pin cross pin
24. Gate locking pin
29. Gate locking pin round head
FIG. 10. End view of gate locking pin and gate locking pin head wherein:
18. Gate locking pin flat head
21. Stop washer bearing
FIG. 11. Enlarged plan view of gate locking pin wherein:
14. Gate locking pin center section
18. Gate locking pin flat head
21. Stop washer bearing
23. Gate locking pin cross pin
FIG. 12. Cut away view of gate segments locked in position with gate locking pin wherein:
5,5' Safety gate segments
14. Gate locking pin center section
15,15' Slots in gate center bar segment for inserting gate locking pin
18. Gate locking pin flat head
21. Stop washer bearing
22. Center bar of gate segment
23. Gate locking pin cross pin
24. Gate locking pin
29. Gate locking pin round head
FIG. 13. Plan view of edge of upper mount anchors of gate vertical frame mounts wherein:
4,4' Upper mount anchor straps
19,19 Slots in leg of upper mount anchor straps
23. Threaded bolt
26. Wing nut
25,25' Leg of upper mount anchor straps
30. Span for doorframe pillar
FIG. 14. Elevation view of upper mount anchor straps wherein:
4' Flat view of upper mount anchor straps
FIG. 15. Elevation view of:
4. Upper mount anchor straps
19. Slots in legs of upper mount anchor straps
25. Leg of upper mount anchor straps
FIG. 16. Plan view of gate threshold wherein:
6. Slot in upper gate threshold
7,7' Threshold legs of gate vertical frame mounts
12. Fastening screw for threshold segments
27. Threaded screw hole in bottom gate threshold
FIG. 17.
1. Doorway frame
2. Gate vertical frame mounts
8. Hinge pin sockets
10. Hinge pin socket mount plate
26. Doorframe threshold
28. Screws to attach hinge pin socket mount plate to doorway frame
DETAILED DESCRIPTION OF INVENTION
This invention is to disclose a doorway safety gate apparatus comprising two gate halves or segments, the halves to overlap on being closed and hinges mounted on outer vertical edge of each gate half, the hinges consisting of hinge pins pointed downward, and mounted on the edge of each gate half and hinge pin sockets mounted on the inside face of the door frame, and a keyway in said hinge pin sockets and hinge pin key segments on the bottom end of the hinge pin and a gate locking pin consisting of a gate locking pin center section and gate locking pin heads of rectangular cross section, one of said gate locking pin heads on each end of the gate locking pin center section and a gate locking pin cross pin and a stop washer bearing located between the cross pin and gate locking pin head, and the cross pin located on the gate locking pin center section to hold the stop washer bearing against center bar of gate segment and gate locking pin head opposite the stop washer bearing against opposite side of center bar of gate and the gate locking pin extending through matching slots of center bars in closed gate halves, and locking of the overlapping gate halves by a quarter rotation turn of the gate locking pin extending through the slots in gate center bars.
In the description which follows, the many legends in the various drawings are duplicates for each gate half or segment, and in view of this the description may mention legends with-without prime (') notation. Each gate half is similarly mounted.
This invention of a doorway safety gate guard comprises gate vertical frame mounts 2 fitting in doorway frame 1. Threshold legs of gate vertical frame mounts 7,7' are fastened together in overlapping position by means of fastening screw for threshold segments 7 and 7'. The threshold legs 7 and 7' straddle the door frame threshold 26, and threaded screw hole 27 is in leg 7 while slot in upper gate threshold 6 is in leg 7'. Legs of upper mount anchor straps 25 are inserted through slots in gate vertical frame mounts 11.
Legs of upper mount anchor straps 25 are fastened in slot for vertical mount upper anchors 11 by means of locking bolts for vertical mount anchor straps 13, the locking bolt extending through slots 19 in legs of anchor straps 25,25' which legs are in sliding contact prior to fastening by bolt 13.
The term "straps" as used in this discussion is meant to indicate for example, metal strap.
It is to be noted that vertical mount upper anchors 4 and 4' are each attached to their respective legs of upper mount anchor straps 25 and 25'. In actual assembly, legs of upper mount anchor straps 25 and 25' are in sliding contact with each other to adjust the span 30 for doorframe pillar 1 between 4 and 4' to securely fasten to doorway pillar frame 1. This is duplicated for each gate half.
Each gate half (segment) 5,5' has hinge pins 9 pointing downward, and mounted on the outer edges of each gate half. Hinge pin sockets 8 are attached to hinge pin socket mount plate 10, which in turn is mounted vertically on inner face of gate vertical frame mounts 2.
The gate halves 5 and 5', in closed position, overlap by various amounts which overlap is a function of doorway width. The closed overlapped gate halves or segments are locked in a closed position by means of gate locking pin 14 which fits in slot in gate segment 15. The slots in gate segment 15 are positioned in center bars of gate segments 22,22'.
Each gate half or segment 5,5' when mounted in position, hinge pins 9 are inserted in hinge pin sockets 8, hinge pin sockets 8 are mounted on hinge pin socket mount plate 10, and hinge pins 9 are held in hinge pin sockets 8 by means of hinge pin keys 16. The hinge pin keys 16 can be withdrawn through hinge pin socket 8 only when the hinge pins are aligned with hinge pin groove keyway slots 17. The hinge pin keys 16 are so aligned with the gate half 5 that the keys 16 can be aligned with hinge pin groove keyway slot 17 only when the gate halves are full open, or 90° from closed.
The gate halves 5,5' are locked in closed position by means of gate locking pin 24, consisting of gate locking pin heads 18 and 29 attached to gate locking pin center section 14. Gate locking pin cross pin 23 is mounted in gate locking pin shaft 14, and a stopwasher bearing 21, having a diameter larger than slots in gate segment 15. The gate locking pin head 18 is of oval or rectangular shape while gate locking pin round head 29 is round and of greater dimension than width of slot 15.
The narrow dimension of pin head 18 will easily slip through slots 15, in center bars of gate segments 22, but the longer dimension of pin head 18 will not slip through the slots 15. The gate halves or segments are then locked together in closed position on rotating the gate locking pin 24 by 90° on insertion of gate locking pin head 18 through slots 15.
Gate sag bumpers 20, are located on the bottom exterior end of each gate half 5,5'.
The preferred doorway safety gate apparatus as described above may be mounted in any doorway but as an alternate, the gate vertical frame mounts 2 may be anchored to the inside of doorway pillar frame 1 by means of screws 28 as shown in FIG. 17. By so mounting the gate vertical frame mounts 2 there is then no need for threshold legs of gate vertical frame mounts 7 and 7'.
The gate halves 5 and 5' are then mounted on the hinges as described above.
There are many different means for locking the closed gate segments 5 and 5' together such as a chain or a bolt inserted through slots in gate segments 15.
A preferred means for locking the gate segments 5 and 5' in a closed position is described below.
The doorway safety gate comprises gate locking means consisting of a gate locking pin 24 and pin heads 18 and 29 attached to each end of gate locking pin center section 14, and a gate locking pin cross pin 23 mounted near one end of the gate locking pin center section 14, and stopwasher bearing 21 in contact with the cross pin 23 so that the gate locking pin 24 is held in position perpendicular to and rotatable in a slot 15 in center bar 22. Pin head 29 if of greater dimension than slot in gate segment 15, and this gate locking pin is rotatable in slots 15. Pin head 18 is of rectangular or oblong configuration such that the short dimension can slip through slot in gate segment 15, and the long dimension or axis is greater than the short axis of slot in gate segment, and gate segments 5 and 5' are then locked together by turning or rotating gate locking pin 24, by 90°.
The lock mechanism for the gate in a closed position comprises the pin 24, having a square hexagon or round head 29 that is larger in dimension than the width of slots 15. The pin 24 is attached to one gate section by being inserted in slot 15, so that the head 29 is seated on surface of the cross bar, and the head is below the surface of flanges of the cross bar 22. A stop washer bearing 21 is placed on the gate locking pin center section 14, and positioned on the opposite surface of center bar from head 29 on gate segment 22. Stop washer bearing 21 is held in position by gate locking pin cross pin 23 inserted crossways in gate locking pin center section 14 to thus attach the gate locking pin 24 to gate cross bar and this gate locking pin 24 is perpendicular to the flat face of the gate. The gate sections 5 and 5' can then be locked in a closed position by entry of pin section and head 18 through slots 15 in gate segments 5 and 5' and the gate locking pin 24 is then rotated 90° to lock the two gate halves together.
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Apparatus is disclosed to provide a safety gate comprised of two segments, which on being closed, the segments overlap each other and can be locked in this closed position. Each gate segment is mounted on hinges in turn fastened to doorway frame pillars. The overlapping gate segments allow for convenience of fitting various widths of door frames.
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FIELD OF THE INVENTION
The field of this invention relates to setting devices for downhole tools that automatically actuate them after certain conditions are met and more particularly focuses on time or temperature or combinations of those conditions.
BACKGROUND OF THE INVENTION
Devices to actuate downhole tools such as external casing packers, for example normally require an inner string to shift a sliding sleeve or a straddle tool to bridge over an inflate port to set the downhole tool. Other techniques involve dropping a ball on a seat or pressurizing the wellbore. Each of these techniques for setting a downhole tool has limitations in certain well conditions and associated costs to implement.
What is needed and made possible by the present invention is a technique to set a downhole tool in an alternative way based on conditions that exist in the wellbore. In a specific embodiment exposure to well fluids at a predetermined temperature for a predetermined time allows the tool to be set. These and other advantages of the present invention will be more apparent to those skilled in the art from a review of the description of the preferred embodiment and associated drawings and the claims that all appear below.
SUMMARY OF THE INVENTION
Setting mechanisms for downhole tools are described that take advantage of hydrostatic pressure in the wellbore which is harnessed to set a tool after exposure to well fluids for a given time or temperature defeats a lock and allows hydrostatic forces to trigger the setting of the tool. Alternatively, some other biasing source is released to set the downhole tool after exposure to well fluids for a time or a temperature and time defeats a lock and allows the biasing source to set the tool. While applications to packers are preferred, other downhole tools can be set in his manner removing the need for an inner string, dropping a ball on a seat or pressurizing the wellbore to achieve the setting of the downhole tool.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a section view in the run in position of a first embodiment that allows hydrostatic or applied well pressure to set a tool after a restraining member is defeated;
FIG. 2 is the view of Figure 1 where the restraining member is sufficiently removed to allow the tool to be set;
FIG. 3 is alternative embodiment to FIG. 1 shown in the run in position;
FIG. 4 is the view of FIG. 3 in the tool set position;
FIG. 5 is a section view in the run in position of an alternative embodiment that employs a stored force within the mechanism to be released and set the downhole tool;
FIG. 6 is the view of FIG. 5 in the tool set position; and
FIG. 7 is an alternative to the FIG. 5 design showing a different restraining material whose removal under well conditions, in the depicted position, sets the tool.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The mandrel 1 of the depicted setting tool S extends to a schematically illustrated downhole tool T that is preferably a packer but can be another type of tool known in the art. Mandrel 1 has a port 9 that is initially covered by a sleeve 6 that has seals 3 and 8 straddling the port 9 to keep it closed. Sleeve 6 is disposed in an internal recess 14 with a restrainer 5 on one side and an energy source 7 on the other side. Energy source 7 can't move the sleeve 6 as long as restrainer 5 is serviceable. A protective sleeve 4 overlays sleeve 6 , energy source 7 and restrainer 5 to protect hem from tools or other objects moved through mandrel 1 . Sleeve 4 allows well fluids in the mandrel 1 to get to restrainer 5 and energy source 7 as will be described below.
Piston 2 covers port 9 and is mounted to mandrel 1 with seals 12 located at or near opposed ends. Seal 13 seals between the mandrel 1 and the piston 2 in a way to define atmospheric chamber 10 near the end opposite from tool T. The energy source 7 can take a variety of forms. It can be a spring, a pressurized chamber, a material that is resilient and installed in a compressed condition or it can be made of a material that grows on contact with well fluids or can in other ways be triggered to assume another shape such as a shape memory material that reverts to a larger size in response to a triggering signal. In whatever form it takes, it needs to be strong enough to shove sleeve 6 over so that seals 3 and 8 no longer straddle port 9 and pressure in mandrel 1 can reach atmospheric chamber 10 to pressurize it and move piston 2 against the tool T. However, none of that can or should happen until the restrainer 5 stops holding sleeve 6 against a force coming from energy source 7 . Restrainer 5 can take various forms. It can be a material that reacts or otherwise interacts with well fluids to get smaller, as shown in FIG. 2 so that well fluid in mandrel 1 could get past port 9 into chamber 11 and slide piston 2 to set the tool T. It can be a material sensitive to the hydrostatic pressure to fail at a given depth. It can be a material sensitive to exposure to a predetermined temperature over a predetermined time so as to allow enough of a delay period for properly positioning the tool T before piston 2 can set it. The selection of the material can be from known materials that exhibit the desired properties. The main desired effect is to allow a sufficient time delay once the tool gets close to where it will be set so that it can be properly positioned before it is automatically set. The specific design of FIGS. 1 and 2 is but one way to accomplish the automatic setting with a delay feature. Having the ability to do this takes away the need for running an inner string or dropping a ball or applying pressure from the surface to set a tool that is delivered downhole.
The setting tool S is somewhat altered in FIGS. 3 and 4 . The main difference is that sleeve 6 has a larger diameter o-ring 3 at one end than o-ring 8 at the other end. As a result of these unequal diameters, the hydrostatic pressure in the mandrel 1 normally exerts a force toward tool T at all times. However, for run in the restrainer 5 is in position and prevents the unbalanced force from moving the sleeve 6 . Since there is always a net unbalanced force on sleeve 6 during run in, there is no longer any need for energy source 7 , as, in effect, the energy source is now the hydrostatic pressure that creates the unbalanced force on sleeve 6 due to the differing end diameters. As before with FIGS. 1 and 2 in the embodiment of FIGS. 3 and 4 nothing happens until the restrainer 5 stops being there by a variety of mechanisms. The time it takes to go away is the delay period that allows proper positioning of the tool T. In the preferred embodiment exposure to a predetermined temperature level for a predetermined time makes the restrainer fail or stop restraining and allows the unbalanced pressure on sleeve 6 to shift it to pressurize chamber 11 which allows the piston 2 to move, since chamber 10 is at atmospheric. FIG. 4 shows the shifted position of piston 2 to set the tool T. The restraint 5 can be a polymer with a glass transition temperature near the expected well temperature at the setting depth. As the temperature is reached the material softens to allow shifting of sleeve 6 , opening of port 9 and the ultimate shifting of the piston 2 . Alternatively the sleeve 6 , restrainer 5 and energy source 7 can be replaced with a sleeve of a shape memory material that initially blocks port 9 but then resumes a former shape that allows flow through port 9 , preferably through a thermal input from being run to the desired location.
FIG. 5 shows another variation using the mandrel 1 and the piston 2 to actuate a tool T. Mandrel 1 has a tab 30 and another tab 32 and between them the restrainer 5 is disposed. Chamber 34 is at atmospheric and is sealed by seals 3 and 6 but piston 2 can't move in response to the hydrostatic pressure acting on it because of restrainer 5 . Ports 36 allow well fluids to reach the restrainer 5 to ultimately make it get smaller or just go away so that there is no longer resistance to the hydrostatic pressure acting on piston 2 thereby allowing it to shift to the right to set the tool T. The set position is shown in FIG. 6 . If a dissolving polymer is used for the restrainer 5 the remains of it will pass through the ports 36 as chunks or in solution. FIG. 7 shows an alternate embodiment to the restrainer 5 that can be a polymer with a low T g so that it simply collapses as seen by comparing FIGS. 5 and 7 . Alternatively the restrainer 5 in FIGS. 5-7 can be a foam or mechanical device that collapses, preferably after a delay upon getting the tool T to a proper depth so as to allow time for proper placement before the automatic setting.
What has been presented in the present invention is a way to automatically actuate tools downhole without the need for a running string, dropping balls or pressuring the wellbore. The common features of the various embodiments are a way to deliver the tool to close to where it will be actuated without it immediately being set. Then, the delay time between the start of the sequence and the actual actuation can be used to secure a final position of tool before it is set. Preferably the delay involves exposure to well fluids coupled with time. Alternatively, there can be an overlay involving the temperature of the well fluids and the time of exposure. The layout of the components and the nature of the material that is used as the restrictor determine the parameters involved in creating the delay insofar as initiating the period and its duration. The selection of materials that are used as a restrictor can vary with the anticipated well conditions. The invention is not necessarily the use of a given material that changes properties over time, in and of itself. Rather, it is the application of such known materials in the context of an automatic setting mechanism that can actuate a wide variety of downhole tools. While a preferred use is actuation of packers, other downhole tools can as easily be actuated such as sliding sleeves, anchors, bridge plugs to name just a few examples. The ultimately unleashed stored force can be available hydrostatic pressure, a resilient material that is installed to hold a stored force, a shape memory material, a pressurized chamber, one or more springs of various types, just to name a few examples.
The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below:
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Setting mechanisms for downhole tools are described that take advantage of hydrostatic pressure in the wellbore which is harnessed to set a tool after exposure to well fluids for a given time or temperature defeats a lock and allows hydrostatic forces to trigger the setting of the tool. Alternatively, some other biasing source is released to set the downhole tool after exposure to well fluids for a time or a temperature and time defeats a lock and allows the biasing source to set the tool. While applications to packers are preferred, other downhole tools can be set in his manner removing the need for an inner string, dropping a ball on a seat or pressurizing the wellbore to achieve the setting of the downhole tool.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of and claims priority in U.S. patent application Ser. No. 13/412,359, filed Mar. 5, 2012, now U.S. Pat. No. 8,880,718, which claims priority in U.S. Provisional Patent Application Ser. No. 61/448,997, filed Mar. 3, 2011, and is related to AUTOMATED BIOMETRIC IDENTIFICATION SYSTEM (ABIS) AND METHOD, U.S. patent application Ser. No. 13/412,512, filed Mar. 5, 2012, which claims priority in U.S. Provisional Patent Application Ser. No. 61/448,972, filed Mar. 3, 2011, and is also related to AUTOMATED BIOMETRIC SUBMISSION AND IMPROVED SCANNING SYSTEM AND METHOD, U.S. patent application Ser. No. 13/095,601, filed Apr. 27, 2011, which claims priority in U.S. Provisional Patent Application Ser. No. 61/328,305, filed Apr. 27, 2010, all of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present disclosed technology relates generally to a system and method for recording, uploading, and utilizing video recorded in real-time, and specifically to a front-end and back-end video archival system and method using video recorded in real-time to aid in emergency or weather response.
[0004] 2. Description of the Related Art
[0005] Digitally watermarking or embedding data into recorded video is well known in the art. Modern mobile phones, digital cameras, and other mobile devices are capable of recording video anywhere a user is located, and uploading that video to common video archive websites, such as youtube.com. These mobile devices may also include GPS functionality, allowing the video to be tagged with location data and other relevant data so that anyone who ultimately views the video can determine where and when a video was taken.
[0006] Presently, such mobile user-submitted videos may be uploaded to video archival or video sharing networks, but the value of the embedded video data is typically underused. For instance, a video may be uploaded to a publicly available video archive database where numerous end users are able to view the video, but the video may not be used immediately and the relevance of the time and location of the video that has been uploaded loses value.
[0007] Typical video archive databases either include embedded video data as an afterthought, or limit the access of that data to selected users. One such example of selective use of video data is U.S. Pat. No. 7,633,914 to Shaffer et al. (the '914 Patent). Although video data may be uploaded and used for assessing critical security or other means in the geographic area of the video data, the '914 Patent relies on users who have already accessed “virtual talk groups” to upload relevant video data. That video data is then only immediately accessible to members of the same virtual talk groups, which limits the effectiveness of the video data to a small number of users.
[0008] Embedded video or photograph data is also used by police departments for accurate evidence collection. U.S. Pat. No 7,487,112 to Barnes, Jr. (the “112 Patent”) describes this ability, but limits the use of the uploaded video or photographic data to the police department. Video or photographic data uploaded to the collection server is stored and not immediately used in any capacity. Such a technique merely simplifies the tasks of a police officer during evidence collection and does not fully embrace the value of embedded video data.
[0009] What is needed is a system which provides mobile users the ability to record video with embedded data, upload that video to a commonly accessible database where the video may be immediately reviewed, and any particular value that can be gathered from the uploaded video be submitted to emergency crews or other relevant parties for immediate review of the recently uploaded video. Heretofore there has not been a video archival system or method with the capabilities of the invention presented herein.
SUMMARY OF THE INVENTION
[0010] Disclosed herein in an exemplary embodiment is a system and method for uploading and archiving video recordings, including a front-end and a back-end application.
[0011] The preferred embodiment of the present invention includes a front-end application wherein video is recorded using a mobile device. The recorded video is embedded with date, time and GPS location data.
[0012] The video is stored on an online back-end database which catalogues the video according to the embedded data elements. The video may be selectively reviewed by relevant experts or emergency personnel for immediate response to the uploaded video and/or distribution to the proper parties. The video may also be archived for later review and use by any number of end-users.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The drawings constitute a part of this specification and include exemplary embodiments of the disclosed subject matter illustrating various objects and features thereof, wherein like references are generally numbered alike in the several views.
[0014] FIG. 1 is a block diagram showing the relationship between the various elements of the preferred embodiment of the present invention.
[0015] FIG. 2 is a flowchart showing the practice of a method of the preferred embodiment of the present invention.
[0016] FIG. 3 is a diagram illustrative of a user interface for viewing videos on a computer utilizing the preferred embodiment of the present invention.
[0017] FIG. 4 is a diagram illustrative of a user interface for viewing archived video associated with the preferred embodiment of the present invention.
[0018] FIG. 5 is a block diagram showing the relationship between various elements of an alternative embodiment of the present invention.
[0019] FIG. 6 is a flowchart showing the practice of a method of an alternative embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
I. Introduction and Environment
[0020] As required, detailed aspects of the disclosed subject matter are disclosed herein; however, it is to be understood that the disclosed aspects are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art how to variously employ the present invention in virtually any appropriately detailed structure.
[0021] Certain terminology will be used in the following description for convenience in reference only and will not be limiting. For example, a personal computer including a display device for viewing a typical web browser or user interface will be commonly referred to throughout the following description. The type of computer, display, or user interface may vary when practicing an embodiment of the present invention.
[0022] A preferred embodiment of the present invention relies on a front-end mobile application 3 associated with a mobile personal computing device 7 , such as a mobile phone, personal digital assistant, or other hand-held computing-capable device. The mobile personal computing device 7 must access a wireless network 16 . A back-end mobile application 17 may be accessed via any personal computing device with capable access to a network, such as the World Wide Web.
II. Geo-Location Video Archive System and Method
[0023] Referring to the drawings in more detail, reference numeral 2 generally refers to a geo-location video archive system, comprising a front-end mobile application 3 , a back-end mobile application 17 , and an end user 30 .
[0024] FIG. 1 demonstrates the relationship between the front-end application 3 , the back-end application 17 , a wireless network 16 , and an end user 30 . The front-end application 3 is comprised of a mobile device 7 . This mobile device 7 may be any hand held mobile device capable of recording and uploading video data via the wireless network 16 to a database server 18 utilized by the back-end application 17 .
[0025] The mobile device 7 includes a camera 4 or other video capture ability capable of recording either still or video images, an antenna 6 , a processor 8 , a wireless network connection 10 , a memory 12 storing an application 14 , and a position reference 13 .
[0026] The antenna 6 is capable of receiving and transmitting data over a wireless network 16 , such as image data recorded by the camera 4 . The processor 8 is adapted for processing all data required by the mobile device. The wireless network connection 10 allows the mobile device 7 to access the wireless network 16 for transmission and reception of data. The memory 12 stores all data necessary for the function of the mobile device 7 , including image data recorded by the camera 4 . An application 14 for accessing the back-end mobile application 17 via the wireless network 16 is stored on the memory. The position reference 13 includes optional two-dimensional or three-dimensional positional information about the mobile device 7 . This positional reference 13 may optionally be attached to image data recorded with the camera 4 .
[0027] The primary purpose of the mobile application 7 is to capture high resolution video by use of the mobile device's 7 camera 4 . The application 14 will collect video in one to ten second slices and transmit it with related data. This data may include Global Positioning System (GPS) location in the form of Longitude and Latitude, Date and Time stamp, description of up to 140 characters, as well as declination based upon magnetic or true north that will be packaged in an XML-formatted file with the phone's ID and a user name. Combined with the video slice, the mobile application will send a “packet” 19 to the database server 18 .
[0028] The back-end mobile application 17 is comprised of a database server 18 which serves to receive all data submitted by mobile devices 7 included in the front-end application 3 , and an optional subject matter expert (expert) 29 capable of reviewing submitted data for real-time use and organized archiving.
[0029] The database server 18 further includes an archive database 20 , a memory 22 , a processor 24 , a video review station application 26 and a user web application 28 . Image data and other data submitted to the database server 18 via the front-end mobile application 3 are stored in the archive database 20 . The video review station application 26 is an optional feature that may be included for use by the expert 29 for reviewing submitted image data and other submitted data. The user web application 28 is an optional feature allowing end users 30 to access data uploaded to the database 18 for personal use.
[0030] Multiple mobile devices 7 may be incorporated with the front-end mobile application 7 . Each front-end application may upload recorded data simultaneously to the database server 18 . The database server 18 will receive a transmission packet 19 from various mobile devices 7 . If this is a new transmission, the video slice and the metadata will be split from the transmission packet and saved into a storage folder located in the archive database 20 . If the packet is a continuation of a current transmission, the video slice will be unpackaged from the packet, and merged with the previously received video slice. In addition the metadata transmitted with the packet will be merged with the current metadata XML. If this is the terminating packet, the video slice will be unpackaged from the packet, and merged with the previously received video slice. In addition, the metadata transmitted with the packet will be merged with the current metadata XML. Once complete, the video file and metadata will be saved into the archive database 20 . Finally, a confirmation 27 of the received video can be sent to the mobile device 7 , confirming that the video transmission was complete. In turn, this information may be made available to another application, web site, or other end user 30 for whatever needs it may have.
III. Database Video Upload, Review, and Use
[0031] In an embodiment of the present invention, an expert 29 will review video files uploaded to the database server 18 through the video review station application 26 . The video review station application 26 will collect video from the front-end application 3 . The application will gather the videos corresponding XML metadata and display the information for the expert 29 . This will include items such as date, time, location, and video length. The expert 29 will then tag the event as a category that best describes the video (i.e. tornado, flood, thunder storm), apply search keywords, and modify the description as needed. The expert 29 will then, using a set of defined standards, grade the video, such as on a rating of one to five “stars.” As examples, five stars may indicate: the highest quality video; video of devastating weather; or video meeting predefined quality definitions. At this time the video can be rejected if it does not meet video submission related requirements. Once this process has been completed, the expert 29 will save the video and corresponding XML to the proper database tables, making it available for searching.
[0032] FIG. 2 demonstrates the practice of the above method in more detail. This will start at 31 when a phenomenon or event occurs at 32 . A mobile user will use their mobile device to capture video of the event at 34 and will upload that video to the database server at 36 . As explained above, the video will be uploaded in slices and will be saved to the archive database at 38 for further review.
[0033] The database will check for raw video submissions at 40 and will determine if a new video has been uploaded or submitted to the server at 42 . If no new video data has been uploaded or submitted, the process continues checking the database for new submissions.
[0034] Upon detecting a new video submission, the video will be transferred to the expert for review at 44 . The expert checks to determine if the video meets the back-end application requirements at 46 . These requirements may include video relevance, video quality, and whether similar videos have already been uploaded for a single event. If the video does not meet all requirements, the video is marked as “rejected” at 48 , saved into a non-searchable database table at 50 , and stored in the video archive database at 38 .
[0035] If the expert determines that the video meets all requirements, the expert will then grade the video based on standard operating procedures at 52 . The video will be categorized at 54 to allow for easy searching of the video through the user web application. Categories may include video location, event description, or other defining terms that will allow end users to easily search for and find the relevant video. Searchable keywords are also added to the video at 56 , which will simplify the video search that will return the particular video being reviewed. The video description will be modified at 58 , if needed. This may be performed if, for example, the mobile user who uploaded the video incorrectly described the video in question. Finally, the video will be saved to searchable database tables at 60 and stored in the video archive database at 38 .
IV. Video Archive Service User Software
[0036] FIGS. 3 and 4 show the typical interface an end user 30 may see when accessing the user web application 28 . The user web application 28 allows all end users 30 to have access to all reviewed and archived videos available.
[0037] In the preferred embodiment, the interface is accessed through a personal computer via the World Wide Web or some other accessible network. FIG. 3 shows a window 61 will be accessed by the end user 30 . The window 61 includes a video playback 62 including a video title 64 , a play/pause button 66 , a play-back progress bar 68 and a progress slider 70 .
[0038] Additional data uploaded along with the video data may be included in the window 61 . This data may include location information about the video, such as longitude 72 , latitude 74 , city 76 , state 78 , and country 80 . Additionally, date 82 , time 84 , and device ID data 86 may be uploaded and stored, embedded within the video data at the time the video was captured. Each of these terms will allow users to find applicable videos relating to what they are searching.
[0039] A description 88 of the video, which may be written by the original mobile user or by the expert 29 , is included in the window, along with a series of search keywords 90 assigned by the expert 29 . The end user 30 has the option of saving the video which results from the user's search at 92 . The video may be stored locally on the end user's machine, or could be stored to the end user's profile so that the user may later return to the searched video. The end user 30 may also perform a new search 94 , including pervious search terms with new terms added, or the user may clear the search 96 and start a completely new search.
[0040] FIG. 4 shows an alternative search window 61 . Here, the end user 30 is capable of viewing the entire archived database list 100 . In the example shown by FIG. 4 , the video archive list 100 organizes the video by date and category, allowing the end user 30 to browse through all videos uploaded and saved to the database.
[0041] Along with the video playback 62 , video title 62 , play/pause button 66 , play-back progress bar 68 and progress slider 70 , the window 61 includes a user video rating 98 . This rating may be assigned by the expert 29 or by end users 30 who visit the site, view the video, and rate the video. The rating will allow future users to determine if there may be a better video to watch, depending on what they may be looking for.
V. Weather Video Archive Application
[0042] In one embodiment of the present invention, the video uploaded to the database 20 relates to current weather occurring somewhere in the world. The mobile user records video of real-time weather activity with a mobile device 7 , uploads this weather video to the database server 18 where it is reviewed by an expert 29 , and the weather video is placed into the archive database 20 where it may be reviewed by end users 30 through the user web application 28 . This allows end users to view an up-to-date weather video of any location where mobile users are uploading video from, including in the end user's immediate vicinity.
[0043] The primary section of interest of the user web application 28 will likely be an interactive map display showing various locations of un-archived video and current weather radar overlays. The user will have the ability to select the grade of video that is displayed on the map. Notifications of videos relating to specific locations will appear on the map as an overlay to indicate the location the video was captured. Hovering over the notifications will allow a brief time lapsed preview of the accompanying video. Activating the notifications will display the full video in a window 61 . At this point the user will have the ability to download the full video, copy link information to embed in a web site, or other video functionality.
VI. 911-V Alternative Embodiment
[0044] An alternative embodiment video upload and archive system 102 encompasses the use of a back-end application 117 that will take video collected from a front-end mobile application 103 , determine its location via longitude and latitude, and upload that information to a 911V system server 118 . If the location where the video has been recorded is within a current 911V application 128 site software installation, the video is automatically routed to the appropriate emergency authority 123 . If the location corresponds to a 911V application 128 site participant, the video is automatically submitted to that 911V emergency authority 123 with the location where the video was recorded. This will allow the site to immediately dispatch emergency services as needed based upon what is shown on the video.
[0045] If the location is not a participant in 911V, a call center specialist 129 contacts the appropriate public safety answer point (PSAP) 130 jurisdiction, based upon the actual location determined by the longitude and latitude embedded in the submitted video. The call center specialist 129 will have the ability to email the video submitted to the 911V system 118 to the PSAP 130 for review. All 911 or 911V contact information will be saved to the videos corresponding XML metadata, for future audits and investigations if needed.
[0046] FIG. 5 is a block diagram showing the interaction between the elements of the front-end mobile application 103 and the back-end mobile application 117 . The front-end application 103 is comprised of a mobile device 107 including a camera 104 or other image recording device, an antenna 106 , a processor 108 , a wireless network connection 110 , memory 112 including a stored application 114 , and a position reference 113 . As in the preferred embodiment, the mobile device 107 records an event with the camera 104 and transmits video data via packets 119 through a wireless network 116 to the back-end mobile application 117 . Position reference 113 is necessarily included with the uploaded video packet 119 to determine where the recorded emergency is occurring and to contact the correct authorities.
[0047] The back-end mobile application 117 is comprised of a 911V system server 118 and call center specialist 129 . The server 118 further includes an archive database 120 , memory 122 , a processor 124 , a video review station application 126 , a notification method 127 , and the 911V application 128 . The call center specialist 129 may review incoming video data and direct the video to the nearest PSAP 130 , or the 911V application 128 will determine the location of the uploaded video data, determine the proper notification method 127 , and automatically forward it to the nearest 911V emergency authority 123 .
[0048] FIG. 6 demonstrates the practice of a method of the alternative embodiment. The method starts at 131 with an emergency phenomenon or event occurring at 132 . A mobile user possessing a mobile device capable of recording and uploading video data captures the video data of the emergency at 134 and uploads it to the 911V web service at 136 . Video slices are stored in the video archive database at 138 as they are uploaded, and the system database checks for newly submitted raw video data at 140 . If no new video is submitted between checks at 142 , the process repeats until new video is detected.
[0049] Once new video is detected at 142 , the system determines the location of the video by longitude and latitude at 144 . The system determines whether the location of the uploaded video is a 911V site at 146 .
[0050] If the site where the video was recorded is located in a 911V site, the video is transferred to the PSAP at 148 and archived as “received and transferred” at 150 and stored in the video archived database at 138 .
[0051] If, however, the location where the video was recorded is not a 911V site, the call center specialist or the system itself will determine the appropriate PSAP jurisdiction to handle the reported emergency at 152 . The proper PSAP is contacted at 154 and the emergency is reported at 156 , including recording the call at 158 and adding contact documentation to the existing XML data at 160 . All of this data is saved to the database at 162 and stored in the video archive database at 138 .
[0052] It will be appreciated that the geo-location video archive system can be used for various other applications. Moreover, the geo-location video archive system can be compiled of additional elements or alternative elements to those mentioned herein, while returning similar results.
[0053] It is to be understood that while certain aspects of the disclosed subject matter have been shown and described, the disclosed subject matter is not limited thereto and encompasses various other embodiments and aspects.
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A system and method for recording, uploading, and archiving video recordings, including a front-end and a back-end application. The preferred embodiment of the present invention includes a front-end application wherein video is recorded using a mobile device. The recorded video is embedded with date, time and GPS location data. The video is stored on an online back-end database which catalogues the video according to the embedded data elements. The video may be selectively reviewed by relevant experts or emergency personnel for immediate response to the uploaded video and/or distribution to the proper parties. The video may also be archived for later review and use by any number of end-users.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is an utility application, which claims priority pursuant to 35 U.S.C. §119(c) to U.S. Provisional Application No. 60/487,495, filed on Jul. 15, 2003. That application is expressly incorporated by reference it its entirety.
BACKGROUND OF INVENTION
[0002] Roller cone rock bits and fixed cutter bits are commonly used in the oil and gas industry for drilling wells. FIG. 1 shows one example of a conventional drilling system drilling an earth formation. The drilling system includes a drilling rig ( 10 ) used to turn a drill string ( 12 ), which extends downward into a well bore ( 14 ). Connected to the end of the drill string ( 12 ) is roller cone-type drill bit ( 20 ) via a bottom hole assembly ( 16 ). A roller cone-type drill bit is shown in further detail in FIG. 2 . Roller cone bits ( 20 ) typically comprise a bit body ( 22 ) having an externally threaded connection at one end ( 24 ), and a plurality of roller cones ( 26 ) (usually three as shown) attached to the other end of the bit and able to rotate with respect to the bit body ( 22 ). Attached to the cones ( 26 ) of the bit ( 20 ) are a plurality of cutting elements ( 28 ) typically arranged in rows about the surface of the cones ( 26 ). The cutting elements ( 28 ) are typically tungsten carbide inserts, polycrystalline diamond compacts, or milled steel teeth.
[0003] Significant expense is involved in the design and manufacture of drill bits. Therefore, having accurate models for simulating and analyzing the drilling characteristics of bits can greatly reduce the cost associated with manufacturing drill bits for testing and analysis purposes. For this reason, several models have been developed and employed for the analysis and design of fixed cutter bits. These fixed cutter simulation models have been particularly useful in that they have provided a means for analyzing the forces acting on the individual cutting elements on the bit, thereby leading to the design of, for example, force-balanced fixed cutter bits and designs having optimal spacing and placing of cutting elements on such bits. By analyzing forces on the individual cutting elements of a bit prior to making the bit, it is possible to avoid expensive trial and error designing of bit configurations that are effective and long lasting.
[0004] However, roller cone bits are more complex than fixed cutter bits in that cutting surfaces of the bit are disposed on the roller cones, wherein each roller cone independently rotates relative to the rotation of the bit body about axes oblique to the axis of the bit body. Additionally, the cutting elements of the roller cone bit deform the earth formation by a combination of compressive fracturing and shearing, whereas fixed cutter bits typically deform the earth formation substantially entirely by shearing. The bit's contact with the earth formation may result in small upward and downward displacements of the bit itself (and/or a bottom hole assembly). This vertical movement is characterized as “bit bounce.” A bit's axial stability is based on the amount of bit bounce that occurs during a drilling operation. Some bit bounce is to be expected during a drilling operation, however, substantial fluctuations in vertical movements result in axial instability. Thus, bit bounce is typically undesirable, because it results in vibrations in the drill string causing inefficiency in the drilling operation and, in some cases, potentially damaging the bit prematurely.
[0005] Accurate analysis of the drilling performance of roller cone bits requires more complex models than for fixed cutter bits. Until recently, no reliable roller cone bit models had been developed which could take into consideration the location, orientation, size, height, and shape of each cutting element on the roller cone, and the interaction of each individual cutting element on the cones with earth formations during drilling.
[0006] In recent years, some researchers have developed a method for modeling roller cone cutter interaction with earth formations. See D. Ma et al, The Computer Simulation of the Interaction Between Roller Bit and Rock , paper no. 29922, Society of Petroleum Engineers, Richardson, Tex. (1995).
[0007] There is a great need to optimize performance of roller cone bits drilling earth formations, particularly with respect to the axial stability of the bits. The axial stability of a bit relates to extent that the bit moves along the axis of the bit (or drill string) during drilling. The axial stability is a function of the weight-on-bit and the reaction forces exerted on the bit by the bottom of the borehole. Any axial instability during drilling will have a negative impact on the bit and the drill string. In addition, axial instability also reduces drilling efficiency. Therefore, it is desirable to have methods for analyzing axial stability of a roller cone bit and for optimizing a roller cone bit to have an improved axial stability.
SUMMARY OF INVENTION
[0008] In general, one aspect of the invention relates to a method for designing a bit for boring in earth formations. The method includes defining parameters for a calculation, wherein the parameters relate to a geometry of the bit, calculating to determine interference between the bit and the earth formations, obtaining vertical displacements with respect to a bit revolution based on the interference between the bit and the earth formations, and applying a criterion to the vertical displacements to evaluate bit performance.
[0009] In general, one aspect of the invention relates to a system for designing a bit for boring in an earth formation. The system includes means for defining parameters for a calculation, wherein the parameters relate to a geometry of the bit, calculating to determine interference between the bit and the earth formations, means for obtaining vertical displacements with respect to a bit revolution based on the interference between the bit and the earth formations, and means for applying a criterion to the vertical displacements to evaluate bit performance.
[0010] In general, one aspect of the invention relates to a method for designing a bottom hole assembly for boring earth formations. The method includes defining parameters for a calculation, wherein the parameters relate to a geometry of a bit of the bottom hole assembly, calculating to determine interference between the bit and the earth formations, obtaining vertical displacements with respect to a bit revolution based on the interference between the bit and the earth formations, and applying a criterion to the vertical displacements to evaluate bit performance with the bottom hole assembly.
[0011] In general, one aspect of the invention relates to a method for designing a bit for boring earth formation. The method includes graphically displaying vertical displacements of the bit interfering with the earth formation, and applying a criterion to the vertical displacements to evaluate bit performance.
[0012] In general, one aspect of the invention relates to a method for designing a bottom hole assembly for boring earth formation. The method includes graphically displaying vertical displacements of the bottom hole as a bit of the bottom hole assembly interferes with the earth formation, and applying a criterion to the vertical displacements to evaluate bit performance with the bottom hole assembly.
[0013] Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
BRIEF DESCRIPTION OF DRAWINGS
[0014] FIG. 1 shows a schematic diagram of a drilling system for drilling earth formations having a drill string attached at one end to a bit.
[0015] FIG. 2 shows a perspective view of a roller cone drill bit.
[0016] FIG. 3 shows a flow chart for analyzing axial stability in accordance with an embodiment of the present invention.
[0017] FIG. 4 shows a cutting element schematic of cutting element interference with earth formations.
[0018] FIGS. 5-7 show an applied weight-on bit and a resultant vertical reaction force.
[0019] FIG. 8 shows a localized bit bounce curve in accordance with an embodiment of the present invention.
[0020] FIG. 9 shows a generalized bit bounce curve in accordance with an embodiment of the present invention.
[0021] FIG. 10 shows a three-dimensional bottom hole profile in accordance with an embodiment of the present invention.
[0022] FIG. 11 shows a two-dimensional bottom hole profile in accordance with an embodiment of the present invention.
[0023] FIG. 12 shows a window of steady-state generalized bit bounce curves in accordance with an embodiment of the present invention.
[0024] FIG. 13 shows a graphical representation of a set of generalized bit bounce curves in accordance with an embodiment of the present invention.
[0025] FIG. 14 shows a computer generated graphical representation of a bottom hole profile in accordance with an embodiment of the present invention.
[0026] FIG. 15 shows a computer system for analyzing axial stability in rock bits in accordance with an embodiment of the present invention.
[0027] FIGS. 16 and 17 are exemplary graphical representations of generalized bit bounce curves in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
[0028] The present invention involves analyzing axial stability through simulation to evaluate cutting structure performance, e.g., ROP, footage drilled, etc. In general, the present invention involves defining a set of parameters of a cutting structure during a drilling operation in a simulation and executing the simulation in view of the defined parameters. The present invention further involves obtaining vertical movements with respect to revolution of the cutting structure and applying a criterion to the vertical movements to evaluate the cutting structure performance.
[0029] In one or more embodiments, the present invention may generally be characterized as comprising three phases: simulation, analysis, and optimization. In the first phase, simulation includes defining a design of a bit for drilling into the earth formations and representing the bit during a drilling operation. One example of a method for simulating a bit drilling through earth formations can be found in U.S. Pat. No. 6,516,293, assigned to the assignee of the present invention, and now incorporated herein by reference in its entirety. Next, the analysis phase involves extracting data from the simulation phase and generating a representation of the data so that a criterion may be applied. Finally, based on whether the bit satisfies the criterion, the design of the bit design may be modified in an optimization phase.
[0030] FIG. 3 shows a flow chart of analyzing axial stability of a bit in accordance with an embodiment of the present invention. In FIG. 3 , the simulation phase comprises Steps 300 and 302 . Initially, a design of a bit for drilling into earth formations is defined (Step 300 ). The bit is simulated during a drilling operation contacting the earth formations. Based on the contact between the earth formations and the bit, a resultant reaction force is determined (Step 302 ).
[0031] A roller cone bit (rock bit) typically includes one or more roller cones. Each roller cone typically includes a plurality of cutting elements (teeth) arranged in one or more rows. Thus, the resultant reaction force of a rock bit may be a sum of reaction force of each individual roller cone. The reaction force of each roller cone in turn may reflect a sum of all reaction forces of the plurality of cutting elements. Accordingly, factors that may influence the resultant reaction force of a rock bit may include, for example, the number of roller cones, the configuration of the roller cones on the rock bit, the configuration and number of cutting elements on each roller cone, etc. In addition, the properties (formation properties) and the bottom hole shape may also influence the resultant reaction forces experienced by the rock bit.
[0032] In one or more embodiments, the resultant reaction force of a rock bit is based on the sum of reaction forces of the individual cutting elements (or teeth) as they contact the earth formations. These reaction forces are a function of both the depth of penetration (B) of individual cutting elements in view of the interference projection area (A) as shown in FIG. 4 .
[0033] FIG. 5 shows a resultant vertical reaction force and a weight-on-bit (WOB). The WOB ( 502 ) is a vertical force applied to the bit via a drill string (not shown). In FIG. 5 , the resultant vertical reaction force ( 504 ) and the WOB ( 502 ) are equal and opposite forces, meaning that the amount of force applied to the bit is equal to the amount of force exerted by the earth formations having contact with the bit. Because the WOB and the resultant reaction force are equal and opposite forces, the bit is not displaced in an upward or downward direction.
[0034] However, when the WOB ( 602 ) is greater than the resultant vertical reaction force ( 604 ) as in FIG. 6 , the bit is displaced in a downward direction (d 1 606 ) by a distance directly proportional to the difference between the WOB ( 602 ) and the resultant vertical reaction force ( 604 ). In other words, the greater the difference between the WOB and the resultant vertical reaction force, the bit is displaced in a downward direction by a greater distance. This downward displacement is considered positive vertical movement, because the bit is penetrating further into the earth formations, i.e., the footage drilled is increasing with respect to the bit revolution.
[0035] Conversely, when the WOB ( 702 ) is less than the resultant vertical reaction force ( 704 ) as in FIG. 7 , the bit is displaced in an upward direction (d 2 706 ) through a distance directly proportional to the difference between the WOB ( 702 ) and the resultant vertical reaction force ( 704 ). Accordingly, the greater the difference between the WOB and the resultant vertical reaction force, the bit is displaced in an upward direction by a greater distance. This upward displacement is considered negative vertical movement, because the bit is not penetrating further into the earth formations, i.e., the footage drilled is not increasing with respect to the bit revolution.
[0036] One skilled in the art will appreciated that determining the vertical movements of a drill bit may include additional forces and the vertical movements of the drill bit may be calculated in a variety of ways.
[0037] Referring back to FIG. 3 , after the resultant reaction force is determined, the analysis phase begins, which comprises Steps 304 - 310 . In the analysis phase, the vertical movements of the bit during the drilling operation are obtained (Step 304 ). The vertical movements of the bit may be obtained during incremental revolutions or times steps or at the conclusion of the simulation. A representation of the obtained vertical movements may be generated. Representations of the obtained vertical movements include, but are not limited to graphs, tables, computer generated graphics, etc.
[0038] FIG. 8 shows a representation of the obtained vertical movements in accordance with an embodiment of the present invention. In FIG. 8 , several vertical movements at particular increments of time (or fractions of a revolution of the bit) are shown as d x , where x is n-6 to n. Mapping these vertical movements produces a localized bit bounce curve ( 800 ), which indicates the vertical movements of the bit during a drilling operation with respect to bit revolution. For example, vertical movements ( 802 , 804 , 806 ) indicate the bit's movement with respect to the bit revolution at three different times during drilling. Vertical movements ( 802 , 806 ) show negative displacement of the bit, whereas vertical movement ( 804 ) shows positive displacement of the bit. FIG. 8 shows a localized perspective of the obtained vertical movements, whereas FIG. 9 shows a generalized representation of the obtained vertical movements. For example, the bit bounce curve ( 800 ) is a sub-section of a bit bounce curve ( 900 ). The generalized bit bounce curve indicates the distance (inches or centimeters) a bit moves with respect to a bit revolution.
[0039] The generalized bit bounce curve ( 900 ) has a generally positive slope indicating that the bit is drilling through the earth formations. The slope ( 902 ) of a bit bounce curve ( 900 ) approximates the rate of penetration, which is the rate a bit cuts through the earth formations. Accordingly, a higher slope indicates a greater rate of penetration.
[0040] Additionally, the bit bounce curve ( 900 ) may be measured over three revolutions of three hundred-sixty degrees (360°) of the bit through the earth formation. For example, the localized bit bounce curve ( 800 ) is measured over one revolution through the earth formation. Preferably, the displacement of the bit is obtained at every three degrees (3°); therefore, the localized bit bounce curve comprises one hundred-twenty data points (all of which are not shown in FIG. 8 ). As such, the bit bounce curve includes three hundred-sixty data points over three revolutions, which map the vertical displacement of the bit with respect to inches. One skilled in the art will appreciate that neither the number of data points nor the particular incremental rotation (or time step) are limitations of the present invention.
[0041] In one or more embodiments, spikes or aberrations may be present in a bit bounce curve, which is typical of insert-rock interaction. Additionally, in on or more embodiments, a bit bounce curve may have a wavy and/or sinusoidal shape.
[0042] The analysis phase continues, after a representation of the vertical movement of the bit has been generated, when a criterion is applied to the generated representation (Step 308 ). In one or more embodiments, the criterion relates to a standard of axial stability. In one or more embodiments, various characteristics may be compiled to generate a criterion by which the axial stability of a bit may be determined.
[0043] For example, the criterion may limit a number of spikes in a bit bounce curve or require a slope of the bit bounce curve to be substantially straight, rather than wavy or the criterion may eliminate the sinusoidal shape of the bit bounce curve. One skilled in the art will understand that the sinusoidal shape of the bit bounce curve typically results in the planar surface of the bottom hole being saddle-shaped, which prevents the bit from performing optimally.
[0044] Alternatively, the criterion may also define minimum and/or maximum fluctuations in the vertical displacement of the bit. For example, referring to FIG. 9 , maximum and minimum curves ( 904 , 906 ) are lines of equal slope ( 902 ) of the bit bounce curve, indicating the upper and lower limits of the desired vertical displacement of the bit. In other words, if the bit where to be displaced above or below maximum and minimum curves ( 904 , 906 ), then the axial stability of the bit may not be optimal. The desired vertical displacements are measured as d max ( 908 ) and d min ( 910 ). In one or more embodiments, d max ( 908 ) and d min ( 910 ) may be equal, however, this is not a limitation of the present invention. Additionally, in one or more embodiments, d max ( 908 ) and/or d min ( 910 ) is less than or equal to one inch (25.4 mm) in three revolutions through the formation. In other words, in a preferred embodiment, the bit is not displaced by more than an inch in a positive or negative direction during drilling. One of ordinary skill in the art will appreciate that the maximum and minimum displacements are dependent on various characteristics, e.g., the properties of the earth formation. Further, one skilled in the art will understand that a minimum curve is the maximum displacement in the positive direction, whereas the maximum curve is the maximum displacement in the negative direction.
[0045] In FIG. 9 , the generalized bit bounce curve ( 900 ) does not exceed the maximum and minimum curves ( 904 , 906 ). If the bit bounce curve ( 900 ) were to exceed the curves ( 904 , 906 ), a design engineer may desire to eliminate or reduce the amount by which the bit bounce curve ( 900 ) exceeds the maximum and/or minimum curves ( 904 , 906 ).
[0046] In another aspect of the invention, FIG. 12 shows a set of generalized bit bounce curves ( 1200 ). For example, the set of generalized bit bounce curves ( 1200 ) indicate the vertical displacement of the bit as it progresses through the earth formation. The set of generalized curves ( 1200 ) begins with a first iteration ( 1202 ) of a bit drilling for several revolutions and terminates with a last iteration as the result of a desired drilling depth being achieved (or the simulation being halted by a user/design engineer). During the first revolution of the first iteration ( 1202 ), the bit has not drilled into the earth formation (0 in.); however, at the end of three revolutions the bit has drilled into the formation. The last iteration ( 1204 ) shows that the bit has drilled more than five inches into the earth formation.
[0047] Typically, the first iteration ( 1202 ) may not be considered, when applying a criterion, because the bit is just beginning to drill into the earth formation. If the earth formation is a smooth planar surface, then the initial contact of the teeth of a roller cone drill bit with the earth formation may result in the first iteration of a bit bounce curve having a slope substantially equal to zero (a horizontal line). Because the first iteration is typically does not necessarily provide the steady-state of the bit, a window ( 1206 ) of the generalized bit bounce curves are considered when applying the criterion. The window ( 1206 ) includes an upper limit ( 1208 ), which is the point at which the steady-state of the bit operation is achieved and this point is measured in inches drilled through the formation. The window ( 1206 ) may also include a lower limit ( 1210 ) defined by the user to reduce the number of curves of consideration with respect to applying a criterion.
[0048] In another embodiment, the criterion may use a bottom hole profile as shown in FIG. 10 . A bottom hole profile is a graphical representation of the shape of a bottom hole being drilled into the earth formation. The bottom hole profile is typically cylindrical in shape, where the terminating planar surface has a particular contour. This contour may be substantially flat, however, irregularities in the contour are expected due to rock failure breakage. The contour may also be saddle-shaped. The shape of the contour is dependent on the bit movement of the bit (axial and lateral) through the earth formation. The more stable movement through the earth formation, the more even (or flat) the contour.
[0049] In FIG. 10 , the bottom hole ( 1004 ) includes a bottom hole contour ( 1002 ), which is the planar surface of the bottom hole drilled by the bit. The bottom hole contour ( 1002 ) is substantially irregular. An intersecting plan ( 1006 ) cuts the bottom hole ( 1004 ), such that the intersecting plan ( 1006 ) is equidistant between the highest peak ( 1010 ) and lowest valley ( 1008 ) of the earth formation.
[0050] FIG. 11 shows a two-dimensional view of the bottom hole contour ( 1004 ′) and intersecting plan ( 1006 ′). Similar to the criterion as mentioned above, the maximum and minimum curves ( 1102 , 1104 ) are at d min and d max ( 1108 , 1110 ) from the intersecting plane ( 1006 ′), where d min and d max ( 1108 , 1110 ) are the minimum and maximum distances that are between the intersecting plane and bottom hole contour. As shown in FIG. 11 , the bottom hole contour ( 1004 ′) exceeds the maximum curve ( 1102 ). In one example, a design engineer may desire to reduce the amount which the highest peak of earth formations formed by drilling exceeds the maximum curve ( 1102 ), such that the highest peak of the bottom hole contour is less than d max ( 1108 ).
[0051] In Step 310 , it is determined whether the current bit design satisfies the criterion. If the criterion is satisfied, then the analysis concludes. Otherwise, the optimization phase is initiated by modifying a bit parameter (Step 312 ) and the bit design is resimulated with the modified bit parameter (Step 314 ). A bit parameter may include location of cutting elements, geometry of cutting elements, orientation of bit, etc.
[0052] FIGS. 13 and 14 show exemplary representations of vertical movements obtained during simulation of a roller cone drill bit drilling through earth formations. The graph in FIG. 13 shows a graphical representation of a set of bit bounce curves ( 1300 ) as the drill bit progresses through the earth formations. The bit bounce curves have relatively flat slope and a wave-like shape. The bit bounce curves also have several spikes. The general slopes of the bit bounce curve indicate increasing penetration into the earth formation. For example, the first bit bounce curve (first iteration ( 1302 )) starts at 0.4 inches and ends at 0.6 inches (end point ( 1304 )), indicating at the beginning of the simulation that the bit has penetrated approximately 0.4 inches into the earth formations and at the end of the bit revolutions, the bit has penetrated approximately an additional 0.20 inches. In the last iteration, the bit bounce curve (last iteration ( 1306 )) begins at approximately 5.40 inches (starting point ( 1308 )) and ends at 5.60 inches (end point ( 1310 )) into the formation.
[0053] FIGS. 16 and 17 are exemplary graphical representations of generalized bit bounce curves. For example, FIG. 16 represents a first design iteration of a bit. The set of bit bounce curves ( 1600 ) are substantially wavy, indicating axial instability. FIG. 17 represents a subsequent design iteration. In this figure, the set of bit bounce curves ( 1700 ) are substantially straight, indicating an axially stable bit. Typically, a designer changes various bit parameters to improve the characteristics of the bit bounce curves.
[0054] In FIG. 14 , a computer-generated graphic of a bottom hole profile ( 1400 ) is used to indicate the vertical movement of the same bit during the drilling simulation. In this case, the bottom hole ( 1402 ) that is cut by the simulated drill bit is inverted to reveal the contour ( 1404 ) of the bottom hole surface. Typically, rough, uneven surfaces indicate a lack of axial stability in a design of a drill bit, whereas smooth, even surfaces indicate an axially stable bit.
[0055] In one or more embodiments of the invention, a bottom hole assembly (BHA) may be analyzed in conjunction with a bit when determining the axial stability. Bottom hole assemblies are designed for specific application and typically include sensors, e.g., for measuring the resitivity, porosity, and density of the formation. Additionally, BHA may include pressures sensors, temperature sensors, etc. One skilled in the art will appreciate that a BHA may have a dampening or magnifying effect on the behavior of a bit bounce curve. Similarly, the BHA may have a dampening or magnifying effect on the shape of a bottom hole profile. Therefore, considering the effects of a BHA on the drilling system provides accurate analysis of a drilling operation.
[0056] In one or more embodiments, the present invention may be implemented on virtually any type computer system regardless of the platform being used. For example, as shown in FIG. 15 , a typical computer system ( 1500 ) includes a processor/simulator ( 1502 ), associated memory ( 1504 ) a storage device ( 1506 ), and numerous other elements and functionalities typical of today's computers (not shown). The computer system ( 1500 ) may also include input means, such as a keyboard ( 1508 ) and a mouse ( 1510 ), and output means, such as a monitor ( 1512 ). Those skilled in the art will appreciate that these input and output means may take other forms in an accessible environment.
[0057] In one or more embodiments, using the keyboard ( 1508 ) and/or mouse ( 1510 ), a user may input initial or modified set of parameters known as simulation input ( 1514 ). The initial or modified parameters are input to the system and used by the processor ( 1502 ) (or simulator) to execute a simulation. The results of the simulation (or simulation output ( 1516 )) in the form of graphics (computer-generated graphics of a bit, bottom hole profile, etc.), graphs (polar plots, box-whisker plots, chart plots, etc.), tables, etc. may be output from the computer system ( 1500 ) and displayed on a monitor ( 1512 ), for example. After reviewing the simulation on the monitor ( 1512 , a user may change a bit parameter using the mouse ( 1510 ) and reinitiate a simulation of the design on the computer system ( 1500 ).
[0058] Advantages of embodiments of the present invention may include one or more of the following. In one or more embodiments, the present invention may be used to minimize behavioral characteristics of axial instability, for example, bit bounce that reduces vibrations in the drilling string thereby improving cutting efficiency. Embodiments of the present invention can potentially increase the life of the bit by preventing damage due to repetitive impact of the cutting structure against the bottom surface of the well bore during drilling.
[0059] While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
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A method for designing a bit for boring earth formations includes defining parameters for a calculation, where the parameters relate to a geometry of the bit, calculating to determine interference between the bit and the earth formations, obtaining vertical displacements with respect to a bit revolution based on the interference between the bit and the earth formations and applying a criterion to the vertical displacements to evaluate bit performance.
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CROSS-REFERENCES TO RELATED APPLICATIONS
The present application claims the benefit of provisional U.S. Application No. 60/805,319, filed Jun. 20, 2006, the full disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The systems and methods of this invention relate to direct electrical stimulation of nerves, nerve bundles, nerve tissue, and regions in proximity to nerves of the body to treat a variety of medical conditions. Specifically, the present invention relates to methods and apparatus for applying such stimulation to selected nerves without the use of conventional lead/electrode systems.
2. Description of the Background Art
Electrical stimulation of nerves, nerve roots, and/or other nerve bundles for the purpose of treating patients has been known and actively practiced for several decades. Application of an electrical field between electrodes to stimulate nerve tissues is known to effectively modify signal pathways both with unidirectional and bidirectional stimulation along the nervous system to signal the brain or to signal organs to alleviate symptoms or control function. These applications are currently practiced with, both, externally applied devices and implanted devices. For example, applying specific electrical pulses to nerve tissue or to peripheral nerve fibers that corresponds to regions of the body afflicted with chronic pain can induce paresthesia, or a subjective sensation of numbness or tingling, or can in effect block pain transmission to the brain from the pain-afflicted regions. Many other examples include electrical stimulation of various branches of the vagus nerve bundle for control of heart rate, mediating hypertension, treating congestive heart failure, controlling movement disorders, treating obesity, treating migraine headache, and effecting the urinary, gastrointestinal, and/or other pelvic structure in order to treat urgency frequency, urinary incontinence, and/or fecal incontinence. Still other branches of the vagus nerve have been used to treat neuropsychiatric disorders. Additionally, applications are also known for electrical stimulation of nerves and nerve bundles in many other specific, selected nerve regions: for example, the pudendal or sacral nerves for controlling the lower urinary tract.
Depending on the individual patient, direct nerve stimulation can effectively modify signal pathways along the nerve, to and from the brain, and to and from organs in the body and thus provide relief of symptoms or control of bodily function. Treatment regimens and targeted nerve locations are known in related art through use of current, common stimulation devices and methods. Commonly implanted devices for nerve stimulation are made by such companies as Cyberonics, Medtronic, Advanced Bionics, and others.
The nervous system is a complex anatomical network that is organized to connect the brain to all areas of the body. The brain uses the nervous system to control bodily processes and adjust the body to its environment. The nervous system is conceptualized by two parts; the central nervous system (CNS), and the peripheral nervous system (PNS). The CNS generally consists of the brain and the spinal cord. The PNS consists of a series of nerves and nerve bundles branching out to all organs and tissue areas of the body. The PNS is connected to the CNS and thus together provides the network of control between the brain and all specific bodily functions. As illustrated in FIG. 1 , the central nervous system is pervasive throughout the body with individual nerves and nerve bundles reaching to all bodily functions. The PNS consists of the cervical, thoracic, lumbar, and sacral nerve trunks leading away from the spine to all regions of the body. The peripheral nervous system also includes cranial nerves. Sensory and control signals travel between the brain and other regions of the body using this network of nerves that all travel along the spinal cord.
Transcutaneous electrical nerve stimulation (TENS) is a well known medical treatment used primarily for symptomatic relief and management of chronic intractable pain and as an adjunctive treatment in the management of post surgical and post traumatic acute pain. TENS involves the application of electrical pulses to the skin of a patient, which pulses are generally of a low frequency and are intended to affect the nervous system in such a way as to suppress the sensation of pain, in the area that the electrodes are applied. This typically would be indicated for use in acute or chronic injury or otherwise used as a protective mechanism against pain. Typically, two electrodes are secured to the skin at appropriately selected locations. Mild electrical impulses are then passed into the skin through the electrodes to interact with the nerves lying thereunder. As a symptomatic treatment, TENS has proven to effectively reduce both chronic and acute pain of patients.
In the context of this application, Specific Nerve Stimulation (SNS) refers to treatments for a variety of medical conditions that apply electrical stimulation directly to nerves, nerve roots, nerve bundles, tissue or regions in proximity to nerves that are in the PNS. Currently available stimulator systems for SNS are fully implanted electronic devices placed subcutaneously under the skin and connected via insulated metal lead(s) to electrodes which are invasively inserted into, around, or onto a nerve or proximate the nerve. A common implanted SNS system contains a battery to power the system. Some implanted SNS systems use an RF wireless connection instead of a battery to power the implanted device. In these RF systems, a receiver device is implanted subcutaneously and a transmitter is worn on the outside of the body. The antenna are tuned to each other and aligned such that control information and power is transmitted to the receiver and then directs the electrical impulses to the electrodes through the leads. The external transmitter contains batteries to power the transmission. All systems have the capability to externally adjust settings of the implanted system through a programming device.
In SNS and TENS systems, electrical energy is delivered through lead wires to the electrodes. For SNS, implanted electrodes are positioned on, around, or in close proximity of the nerve to be stimulated. SNS uses the implanted electrodes to deliver a variety of stimulation modalities including unidirectional and bidirectional propagation along the nerve with the electric pulse waveform defined by a plurality of variables, including, pulse width, pulse frequency (Hz) or duty cycle, amplitude (V), and waveform shape (e.g., mono-phasic or bi-phasic).
SNS is used for treatment of headache, migraine headache, or facial pain by selection of branches in the peripheral nervous system in the cranium or along the vagus nerve bundle. SNS is used for the treatment of chronic pelvic pain due to such conditions as lumbosacral radiculitis, lumbosacral radiculopathy, lumbosacral plexitis, lumbosacral plexopathy, vulvadynia, coccygodynia, peripheral neuritis, and peripheral neuropathy, by applying stimulation to the peripheral nervous system in the sacrum.
SNS is also applied to branches of the vagus nerve in a wide variety of applications, but not limited to the treatment of heart failure; hypertension; obesity; migraine; neuropsychiatric disorders; urinary, gastrointestinal, and/or other pelvic area structures in order to treat urinary urgency, urinary incontinence, and/or fecal incontinence. SNS is also used for severe chronic pain. Stimulation of specific nerves is known to reduce symptoms and enhance the quality of life in patients with chronic pain.
As described above, TENS and SNS devices are battery-powered electronic devices either used transcutaneously (TENS) or implanted (SNS) and connected via insulated metal lead(s) to electrodes which are either placed on the skin (TENS) over the spine or implanted onto, around, or in close proximity to the nerve or nerve bundle selected for stimulation. The implanted electrodes for SNS are positioned on leads that are placed percutaneously, through needle punctures, or through minimally invasive surgical procedures such as laminectomy, or through direct surgical access to position the electrodes on, around, or in proximity to the targeted nerve. On some leads, between 2 and 16 electrodes are available and are positioned in the region that is targeted for electrical stimulation. The implanted leads are then subcutaneously tunneled to the pulse generator (also referred to as a controller) that is implanted in a subcutaneous pocket. The use of these lead wires is associated with significant problems such as complications due to infection, lead failure, lead migration, and electrode/lead dislodgement. Application of electrodes to the nerves can be difficult because of the need to precisely locate electrodes for effective therapy.
Other prior art has attempted to deal with the complications and limitations imposed by the use of electrical leads. For example, self-contained implantable microstimulators and remotely powered microstimulators have been described; however each approach suffers from some significant limitation. A self-contained microstimulator must incorporate a battery or some other power supply; this imposes constraints on size, device lifetime, available stimulation energy, or all three. Due to high use or high energy requirements of the therapeutic stimulation some SNS devices contain recharageable batteries or are powered remotely with an RF coupling to the controller.
For leadless solutions in other similar stimulation applications, remotely powered devices have previously utilized either radiofrequency (RF) or electromagnetic transformer power transmission. RF energy transmission, unless the transmitting and receiving antennae are placed in close proximity, suffers from inefficiency and limited safe power transfer capabilities, limiting its usefulness in applications where recharging or stimulation must be accomplished at any significant depth (>1-2 cm) within the body, in particular where it is desired to permanently implant both the transmitter and receiver-stimulator. Electromagnetic coupling can more efficiently transfer electrical power, and can safely transfer higher levels of power (devices with capacity in excess of 20 Watts have been produced), but again relies on close proximity between transmitting and receiving coils, or the utilization of relatively large devices for deeper (5-8 cm maximum) implantation.
The methods and apparatus of the current invention utilize vibrational energy, particularly at ultrasonic frequencies, to overcome many of the limitations of currently known solutions for selected nerve stimulation, by achieving a nerve stimulation capability without the use of leads connected to a stimulation controller/pulse generator. It is not the intent to limit the scope of this invention to the nerves and nerve bundles in the description but rather to provide a broad solution for stimulation of any selected nerve in the body without the use of leads.
The following patents, all of which are incorporated in this disclosure in their entirety, describe various aspects of using electrical stimulation for achieving various beneficial effects by selected nerve stimulation. U.S. Pat. No. 3,835,833 titled “Method for Obtaining Neurophysiological Effects” by Limoge describes delivery and parameters for electrical stimulation in a TENS stimulation system. U.S. Pat. No. 4,690,144 titled “Wireless Transcutaneous Electrical Tissue Stimulator” by Rise et al. also describes delivery, systems, and application parameters for a TENS stimulation system. U.S. Pat. No. 6,735,475 titled “Fully implantable miniature neurostimulator for stimulation as a therapy for headache and/or facial pain” by Whitehurst et al. describes an implantable microstimulator used for treatment of pain in peripheral nerves generally in the skull or the cervical regions of the spine. U.S. Pat. No. 3,522,811 titled “Implantable Nerve Stimulator and Method of Use” by Schwartz et al. describes an implantable application for stimulation of the carotid sinus nerve as a treatment for hypertension. U.S. Pat. No. 6,615,081 titled “Apparatus and method for adjunct (add-on) treatment of diabetes by neuromodulation with an external stimulator” by Boveja describes an implantable application for stimulation of the vagus nerve as a treatment for diabetes. U.S. Pat. No. 6,684,105 titled “Treatment of disorders by unidirectional nerve stimulation” by Cohen et al. describes an application of electrical stimulation of nerves in unidirectional and bidirectional propagation of the electrical treatment along the nerve. U.S. Pat. No. 5,282,468 titled “Implantable neural electrode” by Klepinski describes an implantable neural electrode for stimulation in contact with nerve tissue. U.S. Pat. No. 5,330,515 titled “Treatment of pain by vagal afferent stimulation” by Rutecki et al. describes an implantable application for stimulation of the vagus nerve as a treatment for pain. U.S. Pat. No. 6,622,038 titled “Treatment of movement disorders by near-diaphragmatic nerve stimulation” by Barrett et al. describes an implantable application for stimulation of branches of the vagus nerve near the diaphragm as a treatment for movement disorders such as epileptic seizure, essential tremor, etc. U.S. Pat. No. 6,622,041 titled “Treatment of congestive heart failure and autonomic cardiovascular drive disorders” by Terry et al. describes an implantable application for stimulation of the cardiac branch of the vagus nerve as a treatment for congestive heart failure. U.S. Pat. No. 5,188,104 titled “Treatment of eating disorders by nerve stimulation” by Wernicke et al. describes an implantable application for stimulation of the vagus nerve as a treatment for eating disorders. U.S. Pat. No. 6,879,859 titled “External pulse generator for adjunct (add-on) treatment of obesity, eating disorders, neurological, neuropsychiatric, and urological disorders” by Boveja describes an external application for stimulation of the vagus nerve as a treatment for a variety of conditions for example, obesity, urological disorders, etc. where the application of the stimulation can be turned off and on by the patient or caregiver. U.S. Pat. No. 6,505,074 titled “Method and apparatus for electrical stimulation adjunct (add-on) treatment of urinary incontinence and urological disorders using an external stimulator” by Boveja describes an external application for stimulation of the sacral nerves and its branches as a treatment for a variety of urological conditions. U.S. Pat. No. 5,215,086 titled “Therapeutic treatment of migraine symptoms by stimulation” by Terry et al. describes an implantable application for stimulation of the vagus nerve as a treatment for migraine headache. U.S. Pat. No. 5,531,778 titled “Circumneural electrode assembly” by Maschino et al. describes an electrode design for attachment to a nerve. U.S. Pat. No. 5,251,634 titled “Helical nerve electrode” by Weinberg describes an electrode design for attachment to a nerve. U.S. Pat. No. 6,622,047 titled “Treatment of neuropsychiatric disorders by near-diaphragmatic nerve stimulation” by Barrett et al. describes an implantable application for stimulation of the vagus nerve as a treatment for neuropsychiatric disorders. U.S. Pat. No. 7,047,078 titled “Methods for stimulating components in, on, or near the pudendal nerve or its branches to achieve selective physiologic responses” by Boggs et al. describes an implantable application for stimulation of the pudenal nerve to control physiologic responses, for example for control of the urinary tract. U.S. Pat. No. 6,002,965 titled “Epidural nerve root stimulation” by Feler et al. describes treating pelvic pain by application of stimulation of nerves in the sacral and lumbar regions of the spine. U.S. Pat. No. 5,405,367 titled “Structure and Method of Manufacture of an Implantable Microstimulator” by Schulman et al. describes an implantable microstimulator used generally for stimulation of tissue. U.S. Pat. No. 6,037,704 titled “Ultrasonic Power Communication System” by Welle describes the use of ultrasound energy transfer from a transmitter to a receiver for purposes of powering a sensor or actuator without being connected by a lead/wire. U.S. Pat. No. 6,366,816 titled “Electronic Stimulation Equipment with Wireless Satellite Units” by Marchesi describes a tissue stimulation system based on a wireless radio transmission requiring the charging of a battery at the receiver and separate command signals used to control the delivery of stimulation. German patent application DE4330680A1 titled “Device for Electrical Stimulation of Cells within a Living Human or Animal” by Zwicker describes a general approach to power transfer using acoustic energy for tissue stimulation.
BRIEF SUMMARY OF THE INVENTION
This invention relates to methods and devices for using electrical stimulation of nerves as a treatment for effectively modulating signal pathways along the nerve, to and from the brain, and to and from organs in the body and thus provide relief of symptoms or control of bodily function. This invention uses vibrational energy as a means to transmit energy and signal information from a first device, to a second device containing means to receive such vibrational energy and converting it into electrical energy and then apply that electrical energy to stimulating electrodes. The first device is intended to be either implanted or to be used externally. The second device is intended to be either permanently or temporarily implanted with stimulating electrodes in contact with or in close proximity to the specific nerve, nerve bundle, nerve branch or nerve root to be stimulated.
This application of leadless electrical stimulation is for specific nerve stimulation applications where the stimulation acts unidirectionally or bidirectionally between the peripheral nerve and the brain. The invention is a system comprising a controller-transmitter, an implanted receiver-stimulator, a programmer to adjust therapy parameters, and stimulation electrodes, such that the stimulation electrodes would be in contact with nerves, in close proximity to the nerve or nerve tissue region to be stimulated to facilitate treatment. Systems incorporating the concepts presented herein have significant advantages over currently available devices, particularly by eliminating the requirement for electrical leads, and by providing the capability for simultaneous or sequenced stimulation of multiple sites.
In one embodiment, the controller-transmitter is implanted. The controller-transmitter is implanted subcutaneously beneath the skin. In another embodiment, the controller-transmitter is applied on the patient's body surface or skin. The transmitted vibrational energy is directed to the receiver-stimulator to cause electrical stimulation at the electrodes of the receiver-stimulator.
In one use of the external embodiment of the controller-transmitter, the device is for treating urge incontinence; in another use of the external embodiment, it is for recurring but non-continuous pain, for example, headache. In the external embodiment, miniaturized receiver-stimulator devices are implanted, but the controller-transmitter unit is external to the body, possibly hand-held or worn attached to a belt or harness. The acoustic energy from the external controller-transmitter is coupled through the skin as well as any underlying tissues, to the implanted device. The external controller-transmitter is under control of the patient. Thus, when the patient begins to feel discomfort, the controller-transmitter unit is applied and/or switched on, and certain characteristics, for example the level of stimulating energy and possibly the frequency or pulse duration of the stimulating waveform, is modified by the user, enabling the user to tailor the stimulation as needed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic showing the basics of the nervous system anatomy.
FIG. 2 is a schematic showing the leadless stimulation system in application with an implantable controller-transmitter for stimulation of a peripheral branch of the vagus nerve.
FIG. 3 is a schematic showing the leadless stimulation system in application with an externally applied controller-transmitter for stimulation of a peripheral branch of the vagus nerve.
FIGS. 4 a and 4 b are block diagrams showing the components of the acoustic controller-transmitter and acoustic receiver-stimulators of the present invention.
FIG. 5 illustrates representative acoustic and electrical signals useful in the systems and methods of the present invention.
FIGS. 6 a , 6 b , and 6 c are schematic illustrations showing components of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The systems and devices describe here comprise a controller-transmitter device that will deliver vibrational energy and signal information to one or more implanted receiver-stimulator device(s) that will convert the vibrational energy to electrical energy of a form that can be used to electrically stimulate nerve tissue. The vibrational energy can be applied with ultrasound as a single burst or as multiple bursts or as a continuous wave with appropriate selection of the following parameters:
Parameter
Value Range
Ultrasound frequency
20 kHz-10 MHz
Burst Length (#cycles)
3-Continuous
Stimulation Pulse
0.1 μsec-Continuous
Duration
Duty Cycle
0-100%
Mechanical Index
≦1.9
The controller-transmitter device would contain one or more ultrasound transducers of appropriate size(s) and aperture(s) to generate sufficient acoustic power to achieve the desired stimulation at the location of an implanted receiver-stimulator device. Additionally, multiple implanted receiver-stimulator devices may be placed within the region insonified by the controller-transmitter device. Multiple receiver-stimulator implants may function simultaneously; it is also possible for multiple devices to function independently, either by responding only to a specific transmitted frequency, or through the use of a selective modulation technique such as pulse width modulation, or through encoding techniques such as time-division multiplexing.
A leadless pulse stimulator would be applied percutaneously or surgically. Utilizing a percutaneous needle delivery technique to access the nerve, a miniaturized receiver-stimulator device disposed within the delivery needle is implanted into tissue or attached to the desired location on the nerve. Various techniques and tools for surgical access and probing of nerve tissue are commonly known. These could be adapted to facilitate delivery of the receiver-stimulator to these locations; the receiver-transmitter may incorporate means to provide permanent attachment to the implant site including possibly helical coils, barbs, tines, or the like or could be adapted in form to surround the nerve as a wrap or along the longitudinal length of the nerve.
Functionally, the receiver-stimulator device comprises an ultrasound transducer to receive acoustic energy and transform it into electrical energy, an electrical circuit to transform the alternating electrical energy into a direct current or a pre-determined waveform, and electrodes to transfer the electrical field energy between an electrode pair to the nerve.
Additionally, a controller-transmitter device is adapted for directional, vibrational energy transmission emitted by the device to intersect the implanted receiver-stimulator. In an implanted version, the controller-transmitter device containing the transmitting transducer is implanted typically just beneath the skin in a subcutaneous space. If not implanted, the transducer portion of the transmitter would be placed over the skin directionally angled to the target region containing the receiver-stimulator with acoustic gel, or other means, used for coupling the acoustic energy to the skin.
In an alternative embodiment, the controller-transmitter device is incorporated into a device also providing conventional lead-based electrical stimulation, in a nerve stimulation system wherein a conventional lead/electrode system would provide stimulus to directly connected regions of the nerve using leads and transmitting vibrational energy to provide stimulation to regions of the nerve where receiver-stimulators are implanted.
The controller-transmitter device would contain similar elements of most currently available stimulator systems including a power source, stimulation control and timing circuitry, physiologic sensing systems, and in the implanted embodiment, a system to communicate with an outside console for data transmission, diagnostic, and programming functions typically through a radiofrequency (RF) link is provided. Additionally, the controller-transmitter device would contain an ultrasound amplifier and one or more ultrasound transducers to generate acoustic energy, and transmit such energy in the general direction of the receiver-stimulator implanted in the body. The duration, timing, and power of the acoustic energy transmission would be controlled as required, per tested parameters that are constructed for specific treatments.
A single receiver-stimulator device is implanted with the electrodes in contact or close proximity to the nerve, as described above, for single-region stimulation; alternatively, it would be possible to implant a plurality of receiver-stimulator devices to stimulate either simultaneously by receiving the same transmitted acoustic energy or independently by responding only to acoustic energy of a specific character (i.e., of a certain frequency, amplitude, or by other modulation or encoding of the acoustic waveform) intended to energize only that specific device. This enables a much more robust utilization of site and region specific stimulation not currently practical with current lead-based implementations whose electrode spacing is fixed on the lead set selected for use and may not adapt itself to the structure of the nerve. Selecting multiple sites and regions for treatments would be greatly enhanced by eliminating the need to connect multiple electrode sites to the stimulation energy source by the use of multiple leads/wires connected to the electrodes or by attempting to anticipate the required spacing between electrodes.
These examples are representative and in no way limiting the applications in which an electro-acoustic stimulator may be utilized to stimulate specific nerves in the body to treat symptoms or control bodily functions.
The delivery of ultrasound energy and, therefore, electrical stimulation could either be automatically triggered based on information received from an internal or external physiological sensor, or be based upon programmed settings, or be manually activated by the patient or other individuals. More specifically, the timing of the initiation of the delivery and/or the duration of the delivery and/or the energy content of the delivery and/or the information content of the delivery could be based upon sensor information or based upon programmed settings or be manually controlled.
Examples of such an electro-acoustic stimulation system as a nerve stimulator are illustrated in FIGS. 2 and 3 .
In FIG. 2 , a controller-transmitter device 1 containing circuitry to provide stimulation control and ultrasound transmission, plus means to communicate with an outside programmer 3 is implanted subcutaneously. It is situated such that the directional angle of the transmitted ultrasound beam would intersect the receiver-stimulator 2 . An ultrasound signal is transmitted by this device through intervening tissue to the receiver-stimulator device 2 containing means to receive this acoustic energy and convert it into an electrical waveform which may then be applied to the attached electrodes. In FIG. 2 , this receiver-stimulator device 2 is shown embedded, in this one example, in the neck region and attached to a peripheral branch of the vagus nerve bundle. The receiver-stimulator device 2 is shown here as a small cylindrical or button-shaped device placed on the nerve in similar ways that current stimulator systems apply electrodes to nerves. Optionally, the receiver-stimulator 2 could be deployed onto the nerve or in proximity to the nerve affixed with an attaching coil or other method. Also optionally (not shown), the receiver-stimulator device 2 could be incorporated into a expandable or self-expanding mechanical mesh that would stay located in the tissue by means of spring tension similar to a stent placement in a vascular application but rather held in place between tissue sections near the nerve.
In FIG. 3 , an externally applied controller-transmitter device 41 containing circuitry to provide stimulation therapy control and ultrasound transmission, plus control means 42 to allow the patient or operator to directly adjust ultrasound output based on desired therapy parameters including, at least, amplitude, pulse duration, and pulse repetition frequency, to produce an effective control of the nerve. The external transmitter 41 may be handheld, or worn on the body, attached by a belt, harness, or the like. The external controller-transmitter 41 is similar to the implantable controller-transmitter device described previously, containing, at the minimum, an adjustable pulse/frequency generator, ultrasound amplifier, ultrasound transmitter, and battery. Optionally, the battery may be a rechargeable type. It is situated such that the directional angle of the transmitted ultrasound beam would intersect the receiver-stimulator 2 . An ultrasound signal is transmitted by this device through intervening tissue to the receiver-stimulator device 2 containing means to receive this acoustic energy and convert it into an electrical waveform which may then be applied to the attached electrodes. In FIG. 3 , this receiver-stimulator device 2 is shown embedded, in this one example, in a branch of the vagus nerve in the region of the stomach as a treatment for obesity.
FIGS. 4 a and 4 b show more details of the system described above and shown in FIG. 2 . In FIG. 4 a , the controller-transmitter device 1 comprises: a battery 10 , one or more sensors 11 , signal processing circuitry 12 , a communications module 13 , a control and timing module 14 , an ultrasound amplifier 15 , and an ultrasound transducer 16 . The battery 10 which provides power for the controller-transmitter may be of a type commonly used in implanted medical devices such as a lithium iodine cell or lithium silver vanadium oxide cell made by Greatbatch, Inc. or which is optionally a rechargeable battery. One or more sensors 11 are used to detect physiological parameters. Suitable sensors are known for the detection of electrical activity, temperature, motion, pressure, and the like. These sensors are connected to signal processing circuitry 12 and optionally used by the circuitry to adjust delivery of stimulation therapy or to communicate diagnostic information from the sensors. The communications module 13 provides a data path to allow the physician to set device parameters and to acquire diagnostic information about the patient and/or the device. The data path may be by an RF communication link, magnetic coupling, ultrasound pulses, or the like, and would communicate to and from an external unit 3 . Device parameters would be used by the control and timing module 14 . Device parameters would include adjustments to transmissions, such as power amplitude, pulse duration, duty cycle, and the like. The control and timing module 14 uses device parameters in conjunction with the acquired physiological data to generate the required control signals for the ultrasound amplifier 15 , which in turn applies electrical energy to the ultrasound transducer 16 , which in turn produces the desired acoustic beam. The controller-transmitter device 1 is encased in a hermetically sealed case 17 constructed of a biologically compatible material, similar to current SNS devices.
Referring to FIG. 4 b , the receiver-stimulator device 2 , implanted in the path of the acoustic beam at the location where electrical stimulation is desired, contains an ultrasound transducer 20 , an electrical circuit 21 , and electrodes 22 . Ultrasound transducer 20 , typically made of a piezoelectric ceramic material, a piezoelectric single crystal, or piezoelectric polymer or copolymer films, intercepts a portion of the transmitted acoustic energy and converts it into an electrical current waveform from the original alternating nature of the applied ultrasound pressure wave. This electrical signal is applied to an electrical circuit 21 which may be one of a type commonly known as an envelope detector, and which may have one of many known circuit configurations; for example, a full-wave rectifier, a half-wave rectifier, a voltage doubler or the like. Electrical circuit 21 produces a voltage pulse with amplitude proportional to the amplitude of the transmitted ultrasound burst and with a pulse length generally equal to the length of the transmitted burst. The circuit 21 may also have different configurations and functions, and provide output signals having characteristics other than a pulse. This signal is applied then to electrodes 22 , which are typically made of platinum, platinum-iridium, gold, or the like. These may be incorporated onto the outer surface of the device, and thus in direct contact within the epidural layer or within close proximity of nerves or nerve fibers which are to be treated by stimulation. Alternatively, the electrodes 22 are connected via wires to a main body that consists of the transducer 20 and electrical circuit 21 and the electrodes 22 are adapted to be shapeable, malleable configurations that conform to the nerve as flexible wraps or the like or that could be placed on the nerve. Electrodes may be adapted that are round, long, segmented, etc. to increase surface area or to control current density at the electrode. Electrodes may be placed on opposing sides of the nerve or in linear alignment with the nerve or in any arrangement suitable for the size and location of the nerve and the targeted nerve stimulation site. The receiver-stimulator device 2 is also enclosed within a sealed case 23 of biologically compatible material
Referring also to previously described FIGS. 4 a and 4 b , FIG. 5 provides detail representing exemplary acoustic and electrical signals of the present system. FIG. 5 first depicts a train of electrical stimulation pulses 31 which have a desired width and are repeated at a desired interval. The controller-transmitter device 1 produces acoustic transmissions 32 , for the desired stimulation pulse width and repeated at the desired stimulation pulse interval, which are emitted from the ultrasound transducer 16 . Below the waveform 32 is shown an enlargement 33 of a single acoustic burst. This burst again has a desired width, a desired oscillation frequency F=1/t, and also a desired acoustic pressure indicated by the peak positive pressure P+ and peak negative pressure P−. The acoustic pressure wave, when striking the receiving transducer 20 of the receiver-stimulator device 2 generates an electrical signal 34 having frequency and burst length matching that of the transmitted waveform 33 and amplitude proportional to the transmitted acoustic pressure (˜+/−P). This electrical waveform is then rectified and filtered by the circuit 21 producing the desired pulse 35 with length equal to the burst length of the transmitted waveform 33 and amplitude (V PULSE ) proportional to the amplitude of the electrical signal 34 . Thus, it can be seen that it is possible in this example to vary the stimulation rate by varying the time between ultrasound bursts, to vary the duration of any one stimulation pulse by varying the duration of the ultrasound burst, and to vary the amplitude of the stimulation pulse by varying the amplitude of the transmitted ultrasound waveform. Circuit 21 could be configured to produce a direct current (DC) output or an alternating current (AC) output, or an output with any arbitrary waveform. Varying the use of signal information within the ultrasound transmission for pulse duration, pulse amplitude, and duty cycle would result in any type of burst sequencing or continuous delivery waveform effective for nerve stimulation. Using signal information in the ultrasound transmission the resultant waveshape may be a square wave, triangle wave, biphasic wave, multi-phase wave, or the like.
In practice, the amount of acoustic energy received by the implanted receiver-stimulator device will vary with ultrasound attenuation caused by loss in the intervening tissue, with spatial location of the receiver-stimulator device with respect to the transmitted ultrasound beam as such a beam is typically non-uniform from edge-to-edge, and possibly with orientation (rotation) of the receiver-stimulator device with respect to the first. Such variation would affect the amplitude of the stimulating pulse for a given ultrasound transmit power (acoustic pressure amplitude). This limitation can be overcome by adjusting the ultrasound transmit power until the resultant stimulation waveform is consistent, a technique similar to that used currently to determine stimulation thresholds at the time of cardiac pacemaker implantation. Another approach would be to automatically adjust using sensing and logic within the first device. The first device would periodically sense the electrical output of the receiver-stimulator device and adjust power transmission accordingly to compensate for any change in the system including relative movement between the transmitting and receiving devices. Yet another embodiment for overcoming this limitation is where the transducer incorporated into the receiver-stimulator device is omni-directional in its reception capability. For example, to improve omni-directional sensitivity, the transducer may be spherical in shape or have specific dimensional characteristics relative to the wavelength of the transmitted ultrasound. Alternatively, multiple transducers are disposed at appropriate angles to reduce or eliminate the directional sensitivity of the device.
FIGS. 6 a through 6 c illustrate two embodiments of a small implantable receiver-stimulator of a cylindrical profile, suitable perhaps for placement by stylet or by injection through a hypodermic needle. FIG. 6 a shows in plan view and 6 b in perspective view such a receiver-stimulator 2 having a hollow, cylindrical ultrasound transducer 71 , a circuit assembly 72 comprising the detector, and two electrodes 73 at either end of the assembly. It can be appreciated that any number of electrodes may be adapted to this embodiment. The transducer 71 would be made of an appropriate piezoelectric ceramic material, having two electrical activity contacts deposited on the outer and inner surfaces of the cylinder, respectively. The transducer and circuit would be encapsulated in an electrically insulating but acoustically transparent medium 74 . The transducer 71 would be of a rigid piezoelectric material, typically a piezo-ceramic with electrodes deposited on the outer and inner surfaces of the cylinder. The circuit assembly 72 may be fabricated using known surface-mount or hybrid assembly techniques, upon either a fiberglass or ceramic substrate. Stimulation electrodes 73 would be fabricated of material commonly used in implanted electrodes, such as platinum, platinum-iridium, or the like. Necessary electrical wiring between the transducer, circuit board, and electrodes is not shown in these drawings. Typical dimensions of such a device would be 1.5 cm in length and 1.5 mm in diameter, and preferably smaller. Multiple electrodes could be adapted as appendages to the embodiment (not shown) or incorporated into fixation elements such as helical screws or barbs (not shown).
As shown in FIG. 6 c , by using hybrid circuit techniques it may be possible to further miniaturize the circuit assembly 72 such that it would fit inside the hollow interior of the transducer 71 . This would have the benefit of substantially reducing the length of the finished device.
While exemplary embodiments have been shown and described in detail for purposes of clarity, it will be clear to those of ordinary skill in the art from a reading of the disclosure that various changes in form or detail, modifications, or other alterations to the invention as described may be made without departing from the true scope of the invention in the appended claims. For example, while specific dimensions and materials for the device have been described, it should be appreciated that changes to the dimensions or the specific materials comprising the device will not detract from the inventive concept. Accordingly, all such changes, modifications, and alterations should be seen as within the scope of the disclosure.
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Systems and methods are disclosed to stimulate nerves to treat medical conditions such as pain, and other conditions, such as, CHF, obesity, incontinence, etc., that could be controlled by the stimulation of the vagal nerves. The invention uses electrical stimulation of the nerve, where vibrational energy from a source is received by an implanted device and converted to electrical energy and the converted electrical energy is used by implanted electrodes to stimulate the pre-determined nerve site. The vibrational energy is generated by a controller-transmitter, which could be implanted or located externally. The vibrational energy is received by a receiver-stimulator, which could be located in the various regions on or around the nerve that needs to be stimulated. The implantable receiver-stimulator stimulates different nerves and regions of a nerve to provide therapeutic benefit.
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BACKGROUND OF THE INVENTION
This invention concerns cone winding of a strand and especially the driving of a package core upon which the strand is being wound.
In winding a strand upon a conical package core, the large end of the cone rotates with a higher peripheral speed than the small end, producing a greater tension on the strand. The different tensions produce changes in the physical characteristics of some types of yarn, which changes are undesirable. The high tension at the wide end may result in breakage of the strand. It is common to drive the cone initially by a frictional engagement with the core intermediate its ends and later by engagement with the strands wound on the core at such driven position. The rate at which the strand is wound over that driven position is thus maintained constant. The rate at which the strand is wound over any other position along the length of the cone is also constant, but increases as the winding progresses toward the large end and decreases as the winding progresses toward the small end. In order to reduce the effect of such changes in the winding rate, various types of strand accumulators have been employed to store some of the strand when the winding rate is low at the small end of the cone and to release the stored strand when the winding rate is high at the larger end of the cone, thus maintaining the tension on the strand substantially constant. This is satisfactory when the strand is being traversed to produce a high helix angle, but it is ineffective to reduce the tension while a creeling tail is being wound on the large end of the cone.
SUMMARY OF THE INVENTION
According to this invention a conical package core is mounted for free rotation about its axis and in peripheral engagement with two frictional drives along a straight line on the conical surface. One drive is located near the large end of the cone -- the second intermediate the ends. The first drive is effective to rotate an empty core, since the frictional force produced thereby is operable on a longer arm (radius of the cone) than that of the second drive. The creeling tail, being wound in a fixed position along the length of the core near the large end, but not under the first drive, is therefore wound at a fixed rate, so that the tension in the strand is constant. When the strand is later traversed between limits established by the small end of the cone at one end and by the nearer of the sides of both the first drive and the base bunch facing the small end of the cone, the strand, or strands, lying between the core and the second drive raise the core out of contact with the first drive and thus transfer the driving function to the second drive.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation of the core, on which the creeling tail is being wound, in relation to the drive therefor.
FIG. 2 is an elevation of the core, during the winding of a strand thereon in helical fashion, in relation to the drive therefor.
The drawings are for illustration only. Some features, such as the strand being wound on the cone, are exaggerated in order to more clearly demonstrate the operation. Only components essential to the operation are shown.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The described embodiment is exemplary and is not intended to define the limits of the invention. Many modifications and substitutions will be obvious to those skilled in the art.
As shown in FIG. 1, a cardboard package core 10 has a conical surface 11 between a large end 12 and a small end 13. Intermediate the ends 12, 13 on the conical surface 11 is an annular medial portion 14 to the described later. Near the large end 12 on the conical surface 11 is an annular end portion, shown as a contact line 15, to be described later. The core 10 is retained between cups 20, 21 engaging ends 12, 13 respectively. The cups have concentric stubs 22, 23 thereon, which are journaled for free rotation in spaced arms 24, 25 capable of oscillating as a unit about an axis (not shown) substantially parallel to and behind axis 16 about which the core 10 rotates, to that the core is movable laterally in the direction of the arrows A, B. The weight of the arms 24, 25 and other components supported thereby, biases the core 10 toward a drive mechanism 30.
The drive mechanism 30 comprises a drive shaft 31 substantially parallel to a generatrix of the conical surface 11 and rotatable in the direction of arrow C by means not shown. A sleeve 32, concentric with and held rigidly on shaft 31, as by pin 33, has two raised annular drive surfaces 34, 35 concentric thereon. The drive surface 34 is located on the sleeve so that it makes contact with the conical surface 11 within medial portion 14. It has a radius of curvature R to reduce scuffing by theoretically maintaining contact with core 10 only along contact line 17 within medial portion 14. The radius of curvature R is large for reasons to be explained later. The drive surface 34 is made of urethane molded onto the sleeve 32. The drive surface 35 is a synthetic rubber O-ring retained in position by a groove 36 in sleeve 32. The groove is located such that the O-ring makes contact with the core 10 only in the end portion 15, which theoretically is only a line. The maximum diameters of the drive surfaces, at which contact is made with the core, are substantially equal.
Initially the core 10 rests upon both drive surfaces 34, 35. When the drive shaft 31 is rotated, the drive surfaces rotate with the shaft, so their peripheral speeds are the same. Since their lines of contact 15, 17 on core 10 form circles of different radii, it is obvious that the core at both circles cannot have the same peripheral speed. Because line 15 has the larger radius, the frictional force exerted by the drive surface 35, which acts on line 15, produces a greater torque than that produced by the frictional force exerted by drive surface 34, acting upon line 17. The result is that drive surface 34 slips along line 17, while drive surface 35 frictionally engages line 15 to rotate core 10.
While the core 10 is driven by the drive surface 35, a strand 40, delivered from a supply (not shown) of said strand through fixed guide 41 and a fixed open-sided guide 42, is wound as a creeling tail 43 in a narrow band near the large end 12 of the core and to either side of line 15. Because the core is driven by drive surface 35 at this time, the peripheral speed of the core at the creeling tail is lower than if drive surface 34 were driving the core. The creeling tail winding speed, being the same as the peripheral speed of the core where the creeling tail is being wound, is thus also reduced, resulting in a constant reduced tension in the strand. When the creeling tail is completed, the strand 40 is moved from fixed guide 42 to an open-sided traversing guide 44, movable back and forth in the directions of arrows D, as by a reciprocating rod 45, to wind a helix between limits 46, 47 on the conical surface 11 of the rotating core 10, as seen in FIG. 2. The limit 46 is closely adjacent to the small end 13, and limit 47 is closely adjacent to whichever of contact line 15 or creeling tail 43 is closest to the small end. As shown, line 15 is closest. As strand 40, being helically wound, approaches contact line 17, it becomes pinched between the core 10 and the drive surface 34, lifting the core out of engagement with both drive surfaces 34, 35. This lifting of the core disengages the frictional drive between drive surface 35 and the core, and transfers it to drive surface 34 in frictional engagement with strand 40, which, in turn, is in frictional engagement with core 10. The line of contact between the drive surface 34 and strand 40 wound on core 10 shifts with the location of the pinched portion of the strand along the helix.
It is the locations of the first and last pinched portions of the helically wound strand 40 that determines the limits of medial portion 14. Until there is always at least one strand pinched between the core and the raised annular surface 34, the core drive will be transferred back and forth between raised annular surfaces 34, 35, creating a fluctuating winding rate, which is undesirable. In order to reduce this fluctuation to a minimum, the width of the raised annular surface 34 should be broad enough to pinch some portion of the strand during each complete revolution of the core. Since, however, the rotational speed is proportional to the radius from axis 16 to the point of contact with drive surface 34, the rotational speed will vary in an amount proportional to the width of medial portion 14, when the core is being rotated by drive surface 34. For this reason, it may be desirable to limit the width of the medial portion to somewhat less than the pitch of the helical angle. In order to reduce slippage and resultant scuffing of the core 10 and strand 40, the drive surface 34 is curved along its length in order to limit the area of contact. The radius of curvature R should be large enough to permit pinching of some portion of the strand during a substantial portion of each complete revolution of the core. In contrast, the drive surface 35 should be narrow to maximize the amount of strand 40 that may be wound on the core 10 and the drive surface should be curved to reduce the area of contact with the core and thus reduce scuffing. For this reason an O-ring with a circular cross-section is preferred. Combining these desirable features the drive surface 35 could be formed by an O-ring with a small circular cross-section, limited by the desired height above the surface of sleeve 32 and the minimum depth of locating groove 36.
A cone winder of the type described (aside from the new frictional drive at the large end 12) is well-known and is customarily used with a tension control device between the strand supply (not shown) and the traversing guide 44. Many such tension controls are known in the art. It is also necessary to employ a tension control with this improved dual drive cone winder, if the tension on the strand is to be controlled.
Although the outer diameters of the drive surfaces 34, 35 are equal in the embodiment described, there is no such requirement, and, while specific materials for the cone 10 and the drive surfaces were mentioned, they are not essential. It is necessary that the materials from which the annular surfaces are made have an adequate coefficient of friction when used in combination with the material of the core 10, that the drive surface 34, adjacent the medial portion 14 of the core, does not seriously abrade the core or the strand, and that the torque produced on the core by this drive mechanism 30 at the end portion 15 exceed the torque produced at the medial portion 14.
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Friction devices are provided for a conical package core in positions near the large end of the core and intermediate the ends of the core. A creeling tail is wound on the large end of the core while the drive near that end is effective to rotate the core. When the strand being wound is transferred to a traversing strand guide, the strand is moved to and fro along the rotating core to produce a helical winding of the strand over the core between the small end and the creeling tail. The strand coming between the core and the intermediate drive lifts the core out of engagement with the drive at the large end.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a combustion system used in sooty smoke generating facilities such as a boiler equipment or a combustion furnace and more particularly to such combustion system provided with control means adapted to control the combustion system so that air polluting substances otherwise contained in exhaust gas generated from the boiler equipment or otherwise contained in exhaust gas generated from the combustion furnace usually used for incineration of general garbage or industrial waste may be effectively collected before emission into the atmosphere, and monitoring means adapted to detect an efficiency deterioration possibly occurring in a dust collector which functions, in turn, to catch and collect sooty dust contained in the exhaust gas from the combustion furnace.
2. Description of the Related Art
Exhaust gas generated from the facilities such as the boiler equipment and the combustion furnace contains sooty dust and the other various air polluting substances. Particularly the exhaust gas generated from urban garbage incinerators contains, in addition to carbon dioxide, water vapor and oxygen, various specified substances under the regulations such as soot and dust, hydrogen chloride (HCl), sulfur oxides (SO x ) and nitrogen oxides (NO x ). These substances are legally regulated, for example, by the Japanese Air Pollution Control Act with respect to its factors such as concentrations and total quantity of emission. The exhaust gas and/or sooty dust additionally contain various heavy metals such as cadmium, chromium and mercury, although they are present in extremely small quantities. Recently, a serious problem for the protection of environment has been posed by hydrogen fluoride (HF) and dioxins which are present in the exhaust gas although they are present also in extremely small quantities.
As for dioxins, the Japanese Ministry of Public Welfare laid down “Preventive guideline against generation of dioxins due to refuse disposal” from the viewpoint that it is desirable to minimize generation as well as emission of dioxins from these facilities into the environment. To prevent or at least minimize dioxins from being generated and emitted from garbage incinerating facilities in accordance with this guideline, addition of suitable neutralizer and/or adsorbent may be utilized or so-called dioxins decreasing condition including a combustion temperature (Temperature), a combustion time (Time) and a turbulence during combustion (Turbulence) in the incinerator may be adjusted depending on various factors such as a total quantity of generated dioxins.
To minimize generation of dioxins, the previously mentioned factors, particularly, the concentration and/or total quantity of dioxins which are being generated must be measured and thereby the current situation must be seized as accurately as possible. However, such measurement is difficult and requires a very expensive analyzer or the like, since the quantity of dioxins contained in the exhaust gas emitted into the atmosphere is extremely small. To solve this problem, it is well known, e.g., as described in Japanese Patent Application Disclosure Gazette No. 1992-161849, to utilize precursors of dioxins such as chlorobenzene and chlorophenol as substitute indices for the measurement.
According to this Patent Application Disclosure Gazette No. 1992-161849, after a quantity of the exhaust gas has been collected from the flue of garbage incinerating facilities, chlorobenzene sampling tube is taken out from the collector and the measurement is carried out using gas chromatography. Such a procedure of measurement necessarily takes a lot of time before the results of measurement can be reflected on the condition under which the operation of the incinerator should be operated.
In order to reflect the results of measurement on the operation of the incinerator, components contained in the exhaust gas must be continuously measured and, in view of this fact, Japanese Patent Application Disclosure Gazette No. 1993-312796 proposed a system for semi-continuous measurement/monitoring of chlorobenzene. However, this system is not adapted for direct measurement of dioxins but adapted for measurement of the substitute substances such as chlorobenzene on the basis of sample gas obtained by pretreating the exhaust gas so as to remove therefrom concomitant moisture and dust. Accordingly, there remains an apprehension that the results of measurement might be prevented from being rapidly and accurately reflected on the condition under which the incinerator should be operated.
On the other hand, the exhaust gas from the incinerator or the like has conventionally been guided to pass through various dust collectors before the exhaust gas is emitted into the atmosphere in order that the regulated substances and the other air polluting substances can be effectively collected from the exhaust gas before they are emitted into the atmosphere.
However, it becomes difficult to trap an adequate quantity of the air polluting substances as the dust collecting efficiency of the dust collector is deteriorated. To restore the desired dust collecting efficiency, cleaning and/or part-exchanging of the dust collector have usually been periodically carried out.
Conventionally, factors such as concentration of the regulated substances and the other air polluting substances contained in the exhaust gas have been detected and assessed according to the prescriptions by Japanese Industrial Standards to avoid the possibility that amounts of these undesirable substances higher than the critical values might be emitted. However, it is substantially impossible to perform detection and assessment in a continuous manner since detection and assessment also are performed on the basis of the sample gas having been subjected to the pretreatment suitable for every one of these substances as in the case of the previously mentioned measurement of chlorobenzene or the like. Consequently, the second best countermeasure has usually been adopted such that the sample gas is periodically collected from the flue and analyzed before the exhaust gas is emitted into the atmosphere.
If the result of measurement indicates that the air polluting substances contained in the sample gas exceed the respective standard values, such result may be sometimes due to an unexpected variation occurring in the condition under which the incinerator operates and/or the deteriorated efficiency of the dust collector. In this case, even if the dust collector is cleaned and/or the parts thereof are exchanged on the basis of measurement data, a certain quantity of the air polluting substances has already been emitted up to that time. In view of this fact, the cleaning of the dust collector and/or the exchange of parts thereof have usually been carried out independently of measurement of the sample gas and at the intervals of a sufficiently short period to minimize emission of the air polluting substances. As a consequence, the cleaning of the dust collector and/or the exchange of parts thereof must be frequently repeated. Frequent cleaning is time consuming and requires much labor, on one hand, and frequent exchange of parts correspondingly increases the maintenance cost.
SUMMARY OF THE INVENTION
In view of the problem as has been described above, it is a first object of the invention to provide a combustion system for sooty smoke generating facilities including an operating condition readjuster adapted to measure and monitor exhaust gas generated from a combustion furnace substantially in continuous mode and thereby to reflect a result of such measurement and monitoring on a condition under which the combustion furnace should be operated so that air polluting substances contained in the exhaust gas may be effectively collected.
The operation controller incorporated in this combustion system for the sooty smoke generating facilities should allow various components contained in the exhaust gas to be continuously monitored and thereby allow a variation occurring in these components to be continuously measured.
In view of such requirements and based on the findings that the concentrations of air polluting substances contained in the exhaust gas gradually increase even after having been treated by a dust collector as the dust collecting efficiency of the dust collector gradually deteriorates, on one hand, and the operation controller allows the exhaust gas to be continuously measured on the other hand, it is the second object of the invention to provide a combustion system for sooty smoke generating facilities including an instrument allowing the dust collecting efficiency of the dust collector to be continuously measured so as to minimize the frequency at which the dust collector should be cleaned and/or part-exchanged and thereby to alleviate the labor for cleaning as well as the cost for parts.
To achieve the objects set forth above, the invention provides a combustion system for sooty smoke generating facilities in which a post-treatment stage for combustion exhaust gas is provided closely adjacent an outlet of a combustion furnace and the combustion exhaust gas is emitted into the atmosphere after having passed through the post-treatment stage, the combustion system comprising an analyzer adapted to composition-analyze the combustion exhaust gas generated from the combustion furnace, a controller adapted to process an analytical signal provided from the analyzer and to output a control signal based on the analytical signal, a neutralizer supplier adapted to, upon receipt of the control signal from the controller, supply the combustion furnace with neutralizers of predetermined types, and an operating condition readjuster adapted to, upon receipt of the control signal from the controller, change at least one of the combustion temperature and the combustion time period of the combustion furnace and the turbulence condition during combustion so as to readjust the operating condition of the combustion furnace, wherein the combustion exhaust gas is introduced from a spot adjacent the outlet of the combustion furnace into the analyzer and wherein, based on the control signal, the neutralizer supplier supplies the combustion furnace with the neutralizers by quantities sufficient to neutralize quantities of respective components contained in the combustion exhaust gas and the operating condition readjuster controllably readjusts the operating condition of the combustion furnace.
Composition of the combustion exhaust gas being present on a spot adjacent the outlet of the combustion furnace is measured by the analyzer which applies, in turn, the controller with an analytical signal based on a result of the measurement. In response to this analytical signal, the controller selects particular types and quantities of neutralizers to be thrown into the combustion furnace in order to neutralize the components which have been determined to have concentrations higher than respectively predetermined values. Simultaneously, the controller applies the neutralizer supplier and the operating condition readjuster with control signals. The control signals associated with the operating condition readjuster instructs the readjuster to change the combustion temperature, the combustion time period and/or the turbulence condition and thereby to achieve controllable changing of the various factors such as the combustion temperature. The neutralizer supplier, upon receipt of the control signals associated with the controller, supplies the combustion furnace with particular types and quantities of neutralizers instructed by the associated control signals. In this way, the air polluting substances contained in the exhaust gas are neutralized and/or the operating condition of the combustion furnace is readjusted so as to suppress generation of the air polluting substances. As a result, emission of the air polluting substances is effectively suppressed.
Concentration of every component contained in the combustion exhaust gas determined at the spot closely adjacent the outlet of the combustion furnace is sufficiently high to facilitate composition-analysis of the exhaust gas. Among all, dioxins contained in the exhaust gas to be measured at the spot closely adjacent the outlet of the combustion furnace are at clearly detectable concentrations, since this analysis is carried out before the exhaust gas passes through the post-treatment stage.
The exhaust gas to be analyzed are of high component-concentrations, allowing the components of the exhaust gas to be continuously measured and monitored.
Measurement carried out at the spot closely adjacent the outlet of the combustion furnace is advantageous in that the demand for supplying the combustion furnace with neutralizers as well as the demand for readjusting the operating condition of the combustion furnace can be rapidly determined and the result of this measurement can be rapidly reflected upon the operating condition of the combustion furnace. Even when the substances to be incinerated are changed, emission of the air polluting substances can be rapidly suppressed.
It should be understood that suitable display and suitable printing such as a plotter may be connected to the controller to display and print the result of the measurement.
The invention provides also a combustion system for sooty smoke generating facilities in which a post-treatment stage for combustion exhaust gas is provided closely adjacent an outlet of the combustion furnace and the combustion exhaust gas is emitted into the atmosphere after having passed through the post-treatment stage, the combustion system comprising a first analyzer adapted to be supplied with the combustion exhaust gas directly from a spot closely adjacent the outlet of the combustion furnace and to composition-analyze the combustion exhaust gas, a second analyzer adapted to composition-analyze the combustion exhaust gas flowing from the post-treatment stage toward a chimney stack, a controller adapted to process an analytical signal provided from the first analyzer and to output a control signal based on the analytical signal, a neutralizer supplier adapted to, upon receipt of the controller signal provided from the controller, supply the combustion furnace with neutralizers of predetermined types, and an operating condition readjuster adapted to, upon receipt of the control signal provided from the controller, change at least one of a combustion temperature and a combustion time period of the combustion furnace and a turbulence condition during combustion so as to readjust the operating condition of the combustion furnace, wherein, based on the control signal, the neutralizer supplier supplies the combustion furnace with the neutralizers by quantities sufficient to neutralize the quantities of respective components contained in the combustion exhaust gas and an operating condition readjuster controllably readjusts the operating condition of the combustion furnace, and wherein the second analyzer monitors the composition of the combustion exhaust gas to be emitted into the atmosphere.
In response to the analytical signal provided from the first analyzer, neutralizers are supplied to the combustion furnace and/or the operating condition of the combustion furnace such as the combustion temperature is changed.
The air polluting substances contained in the combustion exhaust gas generated from the combustion furnace are collected as the combustion exhaust gas passes through the post-treatment stage and then emitted through the chimney stack into the atmosphere. The exhaust gas is introduced into the second analyzer from the flue extending between the post-treatment stage and the chimney stack and analyzed by the second analyzer. In this way, the exhaust gas before being emitted into the atmosphere is reliably monitored.
The analytical result obtained by the second analyzer may be transmitted to a display and/or a printer so as to be displayed and/or printed. It is also possible to transmit the analytical signal to the controller so that, in response to this analytical signal just as in response to the analytical signal provided from the first analyzer, the controller provides control signals to the neutralizer supplier and the operating condition readjuster so that the neutralizer may be supplied to the combustion furnace and the operating condition of the combustion furnace may be controllably readjusted.
It is desirable that the exhaust gas can be measured by the first analyzer also before the exhaust gas reaches the chimney stack and at the same time the facilities can be constructed in a scale as small as possible. To achieve this, the invention provides a combustion system for sooty smoke generating facilities in which a post-treatment stage for combustion exhaust gas is provided closely adjacent an outlet of a combustion furnace and the combustion exhaust gas is emitted into the atmosphere after having passed through the post-treatment stage, the combustion system comprising an analyzer adapted to composition-analyze the combustion exhaust gas, a controller adapted to process an analytical signal provided from the analyzer and to output a control signal based on the analytical signal, a neutralizer supplier adapted to, upon receipt of the control signal provided from the controller, supply the combustion furnace with neutralizers of predetermined types, an operating condition readjuster adapted to, upon receipt of the control signal provided from the controller, change at least one of a combustion temperature and a combustion time period of the combustion furnace and a turbulence condition during combustion so as to controllably readjust the operating condition of the combustion furnace, a first duct through which the combustion exhaust gas is introduced from a spot adjacent the output of the combustion furnace into the analyzer, a second duct through which the combustion exhaust gas flowing from the post-treatment stage toward a chimney stack is introduced into the analyzer, and duct switcher serving to switch the first and second ducts from one to another at predetermined time intervals, wherein, based on the control signal depending on an analytical result of the combustion exhaust gas introduced through the first duct, the neutralizer supplier supplies the combustion furnace with the neutralizers by quantities sufficient to neutralize the quantities of components contained in the combustion exhaust gas, on one hand, and the operating condition readjuster controllably readjusts the operating condition of the combustion furnace, on the other hand, and wherein the composition of the combustion exhaust gas to be emitted into the atmosphere is monitored on the basis of the analytical result of the combustion exhaust gas introduced through the second duct.
The controller may be connected to a suitable display and/or a printer such as a plotter to display and/or print an analytical result obtained from the exhaust gas sampled before it reaches the chimney stack. It is also possible to display and/or print an analytical result obtained from the exhaust gas sampled at the spot closely adjacent the outlet of the combustion furnace.
The time intervals at which the measuring spots are switched may be adjusted in consideration of a time period taken before the combustion exhaust gas generated from the combustion furnace reaches the chimney stack to measure the exhaust gas improved by addition of the neutralizers and/or change of the operating condition. In this manner, the exhaust gas can be continuously monitored.
It is also desirable that a dust collecting efficiency of the dust collector can be continuously monitored. To achieve this, the invention provides a combustion system for sooty smoke generating facilities in which a post-treatment stage for combustion exhaust gas is provided closely adjacent an outlet of a combustion furnace and the combustion exhaust gas is emitted into the atmosphere after having passed through the post-treatment stage, the combustion system comprising a dust collector provided in the post-treatment stage for combustion exhaust gas to collect predetermined substances contained in the exhaust gas generated from the combustion furnace, a first analyzer adapted to be supplied with the exhaust gas from a flue extending between the combustion furnace and the dust collector and to composition-analyze the exhaust gas, a second analyzer adapted to be supplied with the exhaust gas from a flue extending between the dust collector and an outlet immediately into the atmosphere and to composition-analyze the exhaust gas, and a controller adapted to be applied with analytical signals from the first analyzer and second analyzer, respectively, wherein the controller calculates a ratio between a concentration of a given substance determined by the first analyzer and a concentration of this substance determined by the second analyzer and measures a dust collecting efficiency of the dust collector on the basis of this concentration ratio.
Every component of the exhaust gas presents a relatively high concentration immediately after being generated from the combustion furnace. Accordingly, the first analyzer functions to analyze the components of relatively high concentrations. On the other hand, every component of the exhaust gas having passed through the dust collector presents a relatively low concentration because the majority of these components have already been collected. Accordingly, the second analyzer functions to analyze the components of relatively low concentrations. So far as the dust collector maintains a predetermined dust collecting efficiency, initial high concentrations of the components can be lowered to predetermined levels. Deterioration of the dust collecting efficiency makes it impossible. Specifically, a variation in the concentration ratio before and after the dust collector corresponds to a variation in the dust collecting efficiency and it is possible to determine the dust collecting efficiency based on this variation in the concentration ratio. The first and second analyzers composition-analyze the exhaust gas generated substantially at the same time to calculate the concentration ratio, i.e., the exhaust gas partially sampled for the first analyzer is introduced into the second analyzer. Accordingly, composition-analysis by the second analyzer is delayed until the exhaust gas having been introduced into the first analyzer reaches the sampling spot for the second analyzer.
If it is determined on the basis of a measured dust collecting efficiency that the dust collector is not operating with a desired dust collecting efficiency, the dust collector is cleaned or parts thereof are exchanged to restore the desired dust collecting efficiency. It is important for the operator to leave a margin when the dust collecting efficiency is determined to have deteriorated so that the air polluting substances can be reliably prevented from being emitted together with the exhaust gas before determination of such deterioration.
Cleaning and/or part-exchange is carried out only when the dust collecting efficiency is determined to fall below the predetermined level instead of such cleaning and/or part-exchange being carried out periodically regardless of the dust collecting efficiency. In this manner, the frequencies and labors required for the cleaning and/or part-exchange are alleviated and the cost for parts is also reduced.
It is desirable to measure a variation of the dust collecting efficiency while the operating condition of the combustion furnace is controlled and thereby to minimize the frequencies at which the dust collector should be cleaned and/or parts thereof should be exchanged. To achieve this, the invention provides a combustion system for sooty smoke generating facilities in which a post-treatment stage for combustion exhaust gas is provided closely adjacent an outlet of a combustion furnace and the combustion exhaust gas is emitted into the atmosphere after having passed through the post-treatment stage, the combustion system comprising a dust collector provided in the post-treatment stage for the combustion exhaust gas to collect predetermined substances contained in the exhaust gas generated from the combustion furnace, a first analyzer adapted to be supplied with the exhaust gas from a flue extending between the combustion furnace and the dust collector and to composition-analyze the exhaust gas, a second analyzer adapted to be supplied with the exhaust gas from a flue extending between the dust collector and an outlet immediately into the atmosphere, a controller adapted to be applied with analytical signals from the first analyzer and second analyzer, respectively, a neutralizer supplier adapted to, upon receipt of an operation control signal provided by the controller as a result of processing the analytical signal from the first analyzer, supply the combustion furnace with neutralizers of predetermined types, and an operating condition readjuster adapted to, upon receipt of the operation control signal, change at least one of a combustion temperature and a combustion time period of the combustion furnace and a turbulence condition during combustion so as to controllably readjust the operating condition of the combustion furnace, wherein the controller calculates a ratio between a concentration of a given substance determined by the first analyzer and a concentration of this substance determined by the second analyzer and measures a dust collecting efficiency of the dust collector on the basis of the concentration ratio, and wherein, based on the operation signal, the neutralizer supplier supplies the combustion furnace with the neutralizers by quantities sufficient to neutralize respective components contained in the exhaust gas and the operating condition readjuster controllably readjusts the operating condition of the combustion furnace.
It is desirable to employ a single analyzer and thereby not only to reduce a cost of the entire facilities but also to miniaturize the analyzer. To achieve this, the invention provides a combustion system for sooty smoke generating facilities in which a post-treatment stage for combustion exhaust gas is provided closely adjacent an outlet of a combustion furnace and the combustion exhaust gas is emitted into the atmosphere after having passed through the post-treatment stage, the combustion system comprising a dust collector provided in the post-treatment stage for the combustion exhaust gas to collect predetermined substances contained in the exhaust gas generated from the combustion furnace, an analyzer adapted to composition-analyze the exhaust gas, a controller adapted to process an analytical signal provided from the analyzer, a first duct through which the exhaust gas is introduced into the analyzer from a flue extending between the combustion furnace and the dust collector, a second duct through which the exhaust gas is introduced into the analyzer from a flue extending between the dust collector and an outlet immediately into the atmosphere, and a duct switcher adapted to switch the first and second ducts from one to another at predetermined time intervals, wherein the controller calculates a ratio between a concentration of a given substance contained in the exhaust gas introduced through the first duct and a concentration of this substance contained in the exhaust gas introduced through the second duct and measures a dust collecting efficiency of the dust collector on the basis of the concentration ratio.
It is desirable to employ the single analyzer and to measure a variation in the dust collecting efficiency simultaneously with control of the operating condition under which the combustion furnace should operate. To achieve this, the invention provides a combustion system for sooty smoke generating facilities in which a post-treatment stage for the combustion exhaust gas is provided closely adjacent an outlet of a combustion furnace and the combustion exhaust gas is emitted into the atmosphere after having passed through the post-treatment stage, the combustion system comprising a dust collector provided in the post-treatment stage of the combustion furnace to collect predetermined substances contained in the exhaust gas generated from the combustion furnace, an analyzer adapted to composition-analyze the exhaust gas, a controller adapted to process an analytical signal provided from the analyzer, a first duct through which the exhaust gas is introduced into the analyzer from a flue extending between the combustion furnace and the dust collector, a second duct through which the exhaust gas is introduced into the analyzer from a flue extending between the dust collector and an outlet immediately into the atmosphere, a duct switcher adapted to switch the first and second ducts from one to another at predetermined time intervals, a neutralizer supplier adapted to, upon receipt of an operating control signal provided by the controller as a result of processing the analytical signal from the analyzer depending on the combustion exhaust gas introduced through the first duct, supply the combustion furnace with neutralizers of predetermined types, and an operating condition readjuster adapted to, upon receipt of the operation control signal, change at least one of a combustion temperature and a combustion time period of the combustion furnace and a turbulence condition during combustion so as to readjust the operating condition of the combustion furnace, wherein the controller calculates a ratio between a concentration of a given substance contained in the exhaust gas introduced through the first duct and a concentration of this substance contained in the exhaust gas introduced through the second duct and measures a dust collecting efficiency of the dust collector on the basis of this concentration ratio and wherein, based on the operation control signal, the neutralizer supplier supplies the combustion furnace with the neutralizers by quantities sufficient to neutralize respective components contained in the exhaust gas and the operating condition readjuster controllably readjusts the operating condition of the combustion furnace.
The dust collector is preferably provided in the form of a bag filter. In view of the fact that the combustion exhaust gas is emitted into the atmosphere after having passed through the dust collector, it is desirable to monitor a composition of the combustion exhaust gas being emitted into the atmosphere on the basis of concentrations of the predetermined substances determined by the second analyzer or by the single analyzer after having been introduced through the second duct into this single analyzer.
When the concentration ratios fall below the predetermined values, a deterioration of the dust collecting efficiency is suggested and cleaning and/or part-exchange is instructed. In view of this fact, the combustion system preferably further comprises an alarm adapted to be actuated upon receipt of an alarm signal provided from the controller wherein the controller provides the alarm signal when the concentration ratios calculated by the controller fall below the respective predetermined values.
The analyzer should accurately and reliably analyze a composition of the combustion exhaust gas particularly when the component concentrations are relatively high. To achieve this, the analyzer is provided preferably in the form of an infrared spectroscopic analyzer. To measure precursors of the air polluting substances as the corresponding substitute indices, the analyzer is provided preferably in the form of a measuring instrument for CO or O 2 . Particularly for dioxins, from the viewpoint that the measuring precursors of dioxins, the analyzer is provided preferably in the form of a measuring instrument for precursors of dioxins such as chlorophenol, chlorobenzene or PCB (polychlorinated biphenyl).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a structural diagram schematically illustrating the inventive combustion system for sooty smoke generating facilities;
FIG. 2 is a structural diagram schematically illustrating a collector section functioning to collect sample gas and to supply this to the analyzer;
FIG. 3 is a graphic diagram plotting the dust collecting efficiency varying as the time elapses;
FIG. 4 is a graphic diagram plotting the dust purification efficiency depending on the quantity of ammonia used as the neutralizer for nitrogen oxides;
FIG. 5 is a graphic diagram plotting the relationship observed between nitrogen oxides and the temperature at upper part of the furnace;
FIG. 6 is a graphic diagram plotting the collecting rate achieved by the slaked lime for hydrogen chloride and sulfur oxides, depending on the used quantity of the slaked lime; and
FIG. 7 is a graphic diagram plotting the relationship observed between dioxins and the temperature at upper part of the furnace.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Details of the inventive combustion system for sooty smoke generating facilities will be more fully understood from the description of specific embodiments given hereunder in reference with the accompanying drawings. It should be understood here that, in the following description, garbage incinerating facilities will be discussed as a specific example of the sooty smoke generating facilities and the garbage incinerating system in such facilities will be described as a specific example of the inventive combustion system.
FIG. 1 is a structural diagram schematically illustrating such garbage incinerating system. Combustible garbage to be incinerated is thrown into a combustion furnace in the form of a garbage incinerator 1 and combusted therein. Combustion exhaust gas generated during combustion in the garbage incinerator 1 is appropriately cooled as it passes through a heat exchanger 2 forming a post-treatment stage, then fed to a dust collector 3 in which various predetermined substances are collected from the exhaust gas, thereafter fed by an induced draft fan 4 to a chimney stack 5 and finally emitted into the atmosphere. The dust collector 3 may be selected from a group consisting of a cyclone dust collector, an electric precipitator, a bag filter or the like and a combination thereof depending on the particular substances to be collected. The present embodiment employs the bag filter in view of the fact that a mass of dust appropriately accumulating on filter cloth at a high dust collecting efficiency advantageously improve a filtration effect so that even extremely fine particles can be collected. If desired, slaked lime in powdery form may be blown into a zone defined in front of the dust collector or a smoke washing device may be provided in this zone for more effective collection of the air polluting substances such as hydrogen chloride and sulfur oxides.
At a measuring spot A corresponding to the inlet of a flue 6 a through which the combustion exhaust gas is guided from the garbage incinerating furnace 1 to the heat exchanger 2 , i.e., lying adjacent the outlet of the garbage incinerating furnace 1 , a quantity of combustion exhaust gas is collected by a collecting duct 7 a . This collecting duct 7 a communicates via a switching valve 11 serving as a duct switcher with an infrared spectroscopic gas analyzer 10 . A return duct 7 b is connected to the inlet of the flue 6 a at the measuring spot A and, as seen in FIG. 2, communicates with the outlet of an induced draft fan 7 c . The inlet of this induced draft fan 7 c communicates with the collecting duct 7 a at an intermediate point along the collecting duct 7 a . The infrared spectroscopic gas analyzer 10 is adapted to be supplied with sample gas under the action of an induced draft fan 10 a.
At a measuring spot B provided along a flue 6 b extending from the dust collector 3 to the chimney stack 5 , the exhaust gas is collected by a collecting duct 8 a . This collecting duct 8 a communicates via the switching valve 11 with the infrared spectroscopic gas analyzer 10 . A return duct 8 b is connected to the flue 6 b at the measuring spot B and communicates, like the return duct 7 b , with the outlet of the inducted draft fan 8 c . The inlet of this induced draft fan 8 c communicates with the collecting duct 8 a at an intermediate point therealong.
An output signal provided from the infrared spectroscopic gas analyzer 10 is applied as an analytical signal to controller 12 . Based on the analytical signal, the controller 12 calculates a ratio between the concentrations determined on the component substance of the exhaust gas at the measuring spot A and at the measuring spot B and compares the concentration ratio thus calculated with a predetermined reference value of concentration ratio. Obviously, the concentration determined at the measuring spot A is relatively high and the concentration determined at the measuring spot B is relatively low. Accordingly, the concentration ratio calculated when the dust collector 3 is properly operating is higher than the concentration ratio calculated when the dust collector 3 has its collecting function deteriorated. In other words, the reference value of concentration ratio is a threshold on the basis of which it is determined whether the dust collector 3 is fulfilling its expected function or not. The concentration ratio less than this reference value of concentration ratio suggests that the dust collector 3 has its dust collecting efficiency correspondingly deteriorated. FIG. 3 is a graphic diagram plotting the dust collecting efficiency varying as the time elapses. As will be apparent from this graphic diagram, the dust collecting efficiency is deteriorated as the time elapses. The reference value of concentration ratio may be set up to a value leaving a sufficient margin before the critical value for collection of the air polluting substances is reached, for example, to a value corresponding to 85% of the nominal collecting efficiency which should be achieved by the dust collector installed in the combustion system. When the concentration ratio falls below the reference value of concentration ratio, an alarm signal is output from the controller 12 . In addition to the alarm signal, the controller 12 outputs a concentration ratio signal which represents information on the current concentration ratio.
The alarm signal provided from the controller 12 is applied to the alarm 17 which, upon receipt of the alarm signal, activates an alarm buzzer or an alarm siren, or lights or turns on and off an alarm lamp.
The controller 12 determines also, on the basis of the analytical signal, whether the concentration or the other values of the air polluting substances contained in the combustion exhaust gas are less than the predetermined values or not. If the values are determined to be higher than the predetermined values, the controller 12 applies a control signal inclusive of instruction necessary to collect the air polluting substances to the neutralizer supplier 13 and the operating condition readjuster 14 , respectively.
Based on the control signal, the neutralizer supplier 13 supplies the garbage incinerating furnace 1 with the neutralizer. The neutralizer may be selected from those which are well known to be effective for this purpose. FIG. 4 is a graphic diagram plotting the purification rate versus ammonia (NH 3 ) used as the neutralizer, wherein the abscissa indicates NH 3 /No x molar ratio. As will be apparent from FIG. 4, the purification rate is improved as the quantity of neutralizer increases. FIG. 6 is a graphic diagram plotting the collecting rate achieved by slaked lime for hydrogen chloride and sulfur oxides, wherein the abscissa indicates the equivalent ratio of slaked lime. As will be apparent from this graphic diagram, the collecting rate both for hydrogen chloride and sulfur oxides are improved as the quantity of slaked lime used as the neutralizer increases. It should be understood that the collecting rate for hydrogen chloride reaches its saturated state once the equivalent ratio of slaked lime has increased up to 1.0 and the collecting rate remains on the same level even if the equivalent ratio further increases.
The operating condition readjuster 14 controls the condition under which the garbage incinerating furnace 1 operates by adjusting all or any one of the factors such as combustion temperature as well as combustion time in the garbage incinerating furnace 1 and turbulence during combustion or a combination of these factors. It is well known to readjust the operating condition of the garbage incinerating furnace 1 during collection of the air polluting substances. FIG. 5 is a graphic diagram plotting a relationship observed between nitrogen oxides and the temperature at upper part of the furnace. This graphic diagram indicates that the generation of nitrogen oxides is promoted as the temperature rises. FIG. 7 is a graphic diagram plotting a relationship observed between dioxins and the temperature at the upper part of the furnace. As will be understood from this graphic diagram, the generation of dioxins decreases as the temperature rises. Based on such observation, it is the practice to incinerate the garbage in the furnace at a temperature of approximately 900-1200° C. and the combustion exhaust gas is rapidly cooled by the heat exchanger 2 to approximately 200° C. or lower. The incinerating furnace 1 is provided with various measuring instruments associated with the combustion temperature, the combustion time and the turbulence condition, respectively, so that respective measuring signals output from these measuring instruments are applied to the controller 12 .
Additionally, the controller 12 supplies a display control signal to the co display 15 , a print control signal to the printer 16 such as a plotter and a switching instruction signal to the switching valve 11 . The display 15 is adapted to display an analytical result obtained by the infrared spectroscopic gas analyzer 10 and this analytical result is printed by the printer 16 . The display 15 and printer 16 are adapted to display and print a variation in the concentration ratio upon receipt of the concentration ratio information signal from the controller 12 .
The inventive combustion system for sooty smoke generating facilities constructed particularly in the form of the garbage incinerator as has been described hereinabove as well as the operation controller and the dust collecting efficiency measurer both incorporated in the inventive combustion system operate in manners as will be described.
Combustible garbage is transported to the garbage incinerating facilities and thrown into the garbage incinerating furnace 1 . The combustion exhaust gas generated from the furnace 1 is guided from the furnace 1 through the flue 6 a to the heat exchanger 2 in which the combustion exhaust gas is cooled to an appropriate temperature while the initial heat is used to preheat the air for combustion. Then the combustion exhaust gas is guided to the dust collector 3 which collects the polluting substances contained in the exhaust gas.
The exhaust gas having passed through the dust collector 3 is then guided to the chimney stack 5 under the suction by the induced draft fan 4 so as to ascend through the chimney stack 5 and to be emitted at a sufficiently high spot into the atmosphere. While the induced draft fan 4 provides a suction enough to guide the combustion exhaust gas so as to pass through the heat exchanger 2 and the dust collector 3 , there may be provided an additional induced draft fan or forced draft fan at an appropriate location of the flue to guide the combustion exhaust gas more reliably.
The collecting duct 7 a is connected to the flue 6 a at the measuring spot A and the combustion exhaust gas is collected at the measuring point A through the collecting duct 7 a under the suction of the induced draft fan 7 c . The return duct 7 b is connected to the outlet of the induced draft fan 7 c and the outlet end of this return duct 7 b communicates with the collecting duct 7 a at the measuring spot A so that the induced draft fan 7 c may cause the combustion exhaust gas to circulate through the collecting duct 7 a and return duct 7 b communicating with each other at the measuring spot A. At the measuring spot B also, the collecting duct 8 a and return duct 8 b communicate with each other so that the combustion exhaust gas may circulate through the collecting duct 8 a and return duct 8 b.
When the switching valve 11 is operated to bring the collecting duct 7 a in communication with the infrared spectroscopic gas analyzer 10 , on one hand, and the induced draft fan 7 c is deenergized and the induced draft fan 10 a is energized, on the other hand, the quantity of combustion exhaust gas stagnating in the collecting duct 7 a and the return duct 7 b is expelled to the infrared spectroscopic gas analyzer 10 by which the quantity of combustion exhaust gas is composition-analyzed at the measuring spot A. Similarly, when the switching valve 11 is operated so as to bring the collecting duct 8 a in communication with the infrared spectroscopic gas analyzer 10 , the quantity of combustion exhaust gas present at the measuring spot B is composition-analyzed.
The analytical result obtained by the infrared spectroscopic gas analyzer 10 is transmitted to the controller 12 which determines, based on the analytical result, whether the values characterizing the air polluting substances contained in the combustion exhaust gas, inclusive of the concentration values, are less than the predetermined values or not. If the characterizing values are determined to be higher than the predetermined values, the controller 12 supplies both the neutralizer supplier 13 and the operating condition readjuster 14 with the instruction necessary to collect the excessive quantity of the air polluting substances.
If nitrogen oxides are detected to be present in excess of the corresponding predetermined values, the neutralizer supplier 13 is instructed by the controller 12 to supply the garbage incinerating furnace 1 with the neutralizer such as bromine or ammonia. Upon receipt of this instruction, the neutralizer supplier 13 is actuated to throw the neutralizer into the garbage incinerating furnace 1 . If dioxins are detected to be present in excess of the corresponding predetermined values, the operating condition readjuster 14 is instructed by the controller 12 to raise the furnace temperature. This instruction actuates the operating condition readjuster 14 to raise the combustion temperature.
Suitable types of neutralizer may be selectively used depending on the respective air polluting substances, e.g., bromine or ammonia for nitrogen oxides, sodium hydroxide (NaOH) or the like for sulfur oxides, compound of calcium such as calcium hydroxide [Ca(OH) 2 ], calcium oxide (CaO) or calcium carbonate (CaCO 3 ) for dioxins, and slaked lime or hydrated calcium silicate for hydrogen chloride. As for dioxins, there are available various types of adsorbent such as coke and activated carbon. Emission of dioxins can be suppressed, in addition to use of such adsorbent, by readjusting the operating factors of the garbage incinerator furnace 1 such as temperature, stagnating time and intermixing condition of gas components, more specifically, combustion temperature as well as combustion time and turbulence condition during combustion in the incinerating furnace. So-called low-oxygen operation is one of measures which has often been employed to suppress generation of nitrogen oxides. In this manner, the controller 12 instructs the neutralizer supplier 13 and the operation condition readjuster 14 to combine addition of the neutralizer with readjustment of the operating condition so that the air polluting substances may be collected under the optimal condition for the particular garbage incinerator.
The neutralizer thrown into the garbage incinerating furnace 1 reacts with the air polluting substances contained in the combustion exhaust gas to neutralize the air polluting substances. Simultaneously, the operating condition of the garbage incinerating furnace 1 is readjusted by the operating condition readjuster 14 . These countermeasures alleviate or completely eliminate emission of the air polluting substances contained in the combustion exhaust gas into the atmosphere.
When the switching valve 11 is operated so as to bring the collecting duct 8 a in communication with the infrared spectroscopic gas analyzer 10 , the quantity of exhaust gas present at the measuring spot B is composition-analyzed. At the measuring spot B, the exhaust gas may still contain the air polluting substances but in most of cases the majority thereof has already been collected and there is no possibility that the quantities of air polluting substances might exceed the respective standard values. Accordingly, the analytical result obtained as at the measuring spot B is merely transmitted from the controller 12 to the display 15 and the printer so that the analytical result may be displayed and printed and it is not essential to reflect the analytical result upon collection of the air polluting substances.
However, should the exhaust gas still contain detectable quantities of air polluting substances at the measuring spot B, it may lead to pollution of the environment, since the exhaust gas having passed the measuring spot B is subjected to no more filtration and directly emitted into the atmosphere. To minimize such pollution, it is also possible to construct the combustion system so that the controller 12 applies the neutralizer supplier 13 and/or the operating condition readjuster 14 with a control signal which instructs these devices 13 and/or 14 to throw the neutralizer into the furnace and/or to readjust the operating condition of the furnace, respectively.
The measurement is alternately carried out at the measuring spots A and B at predetermined intervals by operating the switching valve 11 . After the composition of the combustion exhaust gas has been improved by the neutralizer supplier 13 as well as the operating condition readjuster 14 , a considerable time is taken before this improved exhaust gas reaches the measuring spot B. The measurement is carried out during a predetermined time period □T sufficient to assure that the improved exhaust gas can reach the measuring spot B and the measurement is switched to that at the measuring spot B after the time period ΔT has elapsed. After a predetermined time period has elapsed, the measurement is switched again to that at the measuring spot A. It is also possible to set the predetermined time period elapsing before the measurement is switched again to that at the measurement spot A so as to be equal to the time period ΔT, i.e., the measurement spot may be switched at uniform intervals of the time period ΔT.
The predetermined time period ΔT depends on a velocity of gas flow and lengths of flues which depend, in turn, on a scale of the garbage incinerator. When the lengths of the respective collecting ducts 7 a , 8 a extending from the sample gas collecting spots to the infrared spectroscopic gas analyzer 10 are relatively long, a quantity of still not improved exhaust gas may stagnate in these collecting ducts 7 a , 8 a even after the predetermined time period ΔT has elapsed. Therefore, it is necessary to exchange such stagnating exhaust gas with the improved exhaust gas before the composition-analysis is carried out. The exchange can be achieved, for example, by energizing the induced draft fan 10 a for a predetermined time period to expel the quantity of exhaust gas stagnating in the collector ducts and the return ducts and thereafter by supplying the infrared spectroscopic gas analyzer 10 with the improved exhaust gas. Accordingly, it is desirable to set the time period ΔT in consideration also of a time period necessary for such forcible gas exchange.
Switching of the measuring spots at the predetermined intervals of ΔT in the manner as has been described above allows the combustion exhaust gas to be continuously composition-analyzed even when the combustion exhaust gas is being effectively improved under the action of the neutralizer supplier 13 and/or the operating condition readjuster 14 . In other words, the combustion exhaust gas can be continuously monitored.
While the system according to the invention has been described hereinabove based on the specific embodiment in which the composition-analysis is alternately carried out at two measuring spots A, B, the composition-analysis at the measuring spot B is not essential since the incinerating furnace can be adequately controlled merely by the composition-analysis at the measuring spot A so as to achieve desired elimination or alleviation of the air polluting substances emitted therefrom into the atmosphere.
The controller 12 calculates, on the basis of the analytical signals obtained at the respective measuring spots A and B, a ratio between the concentration determined at the measuring spot A and the concentration determined at the measuring spot B with respect to the given constituent contained in the exhaust gas. The constituent subjected to such calculation of the concentration ratio is not limited to the air polluting substances so far as it can be easily analyzed at either measuring spot A or B and such calculation of the concentration ratio may be carried out with respect to two or more constituents. Information on the concentration ratio is applied in the form of a concentration ratio data signal to the display 15 and the printer 16 to be displayed by the display 15 and printed by the printer 16 , respectively. It should be understood that, when two or more constituents are concerned, the respective concentration ratios are preferably displayed and printed separately of one another.
The calculated concentration ratio is compared to the corresponding reference value of concentration ratio registered in the controller 12 . If this calculated concentration ratio is less than the reference value of concentration ratio, the alarm signal is applied from the controller 12 to the alarm 17 . Upon receipt of this alarm signal, the alarm 17 provides its alarm function in a predetermined form. In the case of two or more constituents of which the respective concentration ratios must be calculated, the system may be arranged, for example, so that the alarm signal is transmitted from the controller 12 to the alarm 17 when the respective concentration ratios of more than half of these constituents are less than the corresponding reference values of concentration ratio.
The alarm function may be, for example, generation of alarm sound from an alarm buzzer or siren, or turning on/off or lighting of an alarm lamp. As for the alarm lamp, both the turn on/off and the lighting may be used, if desired. For example, there may be provided a pair of the reference concentration ratio values for one and same constituent of the exhaust gas. In this case, the alarm lamp may be adapted to be turned on/off when the calculated concentration ratio is less than the first reference value and to be put on the light when the calculated concentration ratio is less than the second reference value. These two different forms of alarm function may be advantageously used also when the concentration ratio is simultaneously calculated on a plurality of substances. In this case, the alarm lamp may be adapted to be turned on/off when the concentration ratio calculated on one of the substances is less than the corresponding reference value of concentration ratio value and to be lit when the concentration ratios calculated on more than half of the substances are less than the respective reference values of concentration ratio.
Actuation of the alarm 17 suggests that the dust collector 3 can no more fulfill its expected efficiency and immediately must be cleaned and/or part-exchanged to restore its expected dust collecting efficiency.
As will be apparent from the foregoing description, the inventive combustion system for sooty smoke generating facilities allows the sample gas of high component concentration to be directly subjected to analysis by composition-analyzing the combustion exhaust gas immediately at the outlet of the garbage incinerating furnace. In this way, composition-analysis of the combustion exhaust gas can be achieved not only easily but also in substantially continuous manner. Consequently, the analytical result can be reflected on the operating condition of the garbage incinerating furnace and thereby the air polluting substances contained in the exhaust gas can be rapidly collected. Continuous analysis of the exhaust gas, one of the most important features of the invention, allows the quantity of neutralizer to be thrown into the furnace to be properly controlled. Thereby the cost of the neutralizer can be minimized and, in consequence, the air polluting substances contained in the exhaust gas can be collected at the correspondingly reduced cost.
According the invention, the exhaust gas is composition-analyzed before and behind the dust collector and then the concentration ratio is calculated on one or more predetermined substance(s) so that a change in the dust collecting efficiency of the dust collector is detected on the basis of a change in the concentration ratio(s). Detection of dust collecting efficiency enables the dust collector operator to determine a proper timing, i.e., frequency for cleaning and/or part-exchanging of the dust collector. In this manner, time and labor for operation of such cleaning and/or part-exchanging can be alleviated and the cost of the parts can be also reduced.
The exhaust gas destined to be emitted into the atmosphere is composition-analyzed and thereby monitored so that the air polluting substances may be effectively collected before they are emitted into the atmosphere.
As another important feature of the invention, the analyzer is operatively associated with two ducts and respective ends of these two ducts opposite to those communicating with the analyzer are connected to the exhaust gas duct at different spots. Such arrangement allows the exhaust gas to be analyzed by the single analyzer at the outlet of the combustion furnace and the spot immediately before which the exhaust gas is emitted into the atmosphere, i.e., before and behind the dust collector. In addition, the measuring spots are switched from one to another at the predetermined intervals and thereby the exhaust gas can be continuously composition-analyzed at either measuring spot.
Furthermore, actuation of the alarm allows the operator to determine the proper timing for cleaning and/or part-exchanging of the dust collector without relying upon the printed data of the variation occurring in the concentration ratio.
Use of the infrared spectroscopic gas analyzer as the analyzer allows the operator to measure not only the air polluting substances but also the other various substances in order to determine the currently available dust collecting efficiency so far as the other various substances are suitable for calculation of the concentration ratio. Moreover, the invention can provide the operating condition readjuster at a relatively low cost. Therefore, the combustion system according to the invention correspondingly reduce the construction cost for the garbage incinerating facilities and can be readily installed in the existing sooty smoke generating facilities.
A bag filter may be used as the dust collector to catch various substances contained in the exhaust gas as completely as possible and thereby to alleviate or eliminate the air polluting substances which otherwise might be emitted into the atmosphere.
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A combustion system for reducing an amount of air polluting substances in a combustion exhaust gas produced in a combustion furnace comprises a combustion furnace configured to produce a combustion exhaust gas upon combustion of a combustible material, wherein the combustion exhaust gas contains an amount of air polluting substances; an analyzer suitable for analyzing the combustion exhaust gas and producing an analytical signal; a conduit suitable for conducting the combustion exhaust gas from the outlet opening to the analyzer, wherein the conduit is located adjacent the outlet opening of the combustion furnace; a controller suitable for processing the analytical signal produced by the analyzer and outputting a first control signal and a second control signal, based on the analytical signal; a neutralizer supplier suitable for supplying the combustion furnace with an amount of neutralizers to reduce the amount of air polluting substances in the combustion exhaust gas, wherein the amount of neutralizers supplied to the combustion furnace is based on the first control signal outputted by the controller; and an operating condition readjuster suitable for readjusting at least one operating condition of the combustion furnace selected from the group consisting of (1) a temperature of the combustion furnace, (2) a time for combusting the combustible material, and (3) an air flow in the combustible furnace, to reduce the amount of air polluting substances in the combustion exhaust gas, wherein the at least one operating condition is readjusted based on the second control signal outputted by the controller.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation application of PCT/EP03/01885, filed Feb. 25, 2003, which is incorporated herein by reference in its entirety, and also claims the benefit of German Priority Application No. 102 08 265.0, filed Feb. 26, 2002.
FIELD OF THE INVENTION
[0002] The present invention relates to a process for the preparation of cosmetic or dermatological preparations, in particular of preparations comprising emulsions, PIT emulsions and washing-active substances.
BACKGROUND OF THE INVENTION
[0003] Cosmetic or dermatological preparations in the form of emulsions, PIT emulsions and preparations comprising washing-active substances are widespread. Emulsions may be W/O or O/W emulsions or else multiple emulsions, i.e. emulsions containing more than two phases. They are sold in the form of creams, lotions, but also as perspiration-inhibiting, body-odour-reducing cleansing and sunscreen preparations. PIT emulsions are particular forms of emulsions. They are characterized by the method of their preparation and the droplet sizes resulting therefrom. For the preparation, emulsifiers or emulsifier systems are used which change their polarity depending on the temperature, meaning that phase inversion arises during the preparation. As a result of this phase inversion, particular product properties are achieved, such as, for example, a particular optical appearance or an extraordinarily low viscosity. Such preparations are suitable, for example, as sprayable skincare or sunscreen emulsions. Finally, preparations comprising washing-active substances are used as body- or hair-cleansing compositions, and also as dishwashing detergents.
[0004] Usually, such preparations are prepared in a batchwise process, mostly in a mixer into which the starting substances are introduced and the intermediate or end product are removed after a certain operating time. In this process, all of the process steps which are required for the preparation of the product take place in this one apparatus one after the other: metering, mixing, heating/cooling, emulsifying, cooling. Often, upon removing the product, the product is subjected to subsequent homogenization. Although in food technology continuous plants for the preparation of emulsions such as yoghurt or mayonnaise are widespread, cosmetic or dermatological preparations are only prepared continuously in exceptional cases. This is because the requirements on the stability of cosmetic products are much higher and, due to their more complex composition comprising numerous different components, said products are much more difficult to prepare in stable form. Thus, for example, for a yoghurt, a stability in the region of a few weeks is expected, whereas cosmetic emulsions should be stable over at least 30 months.
[0005] Plants which are operated in batchwise processes have a series of disadvantages besides the advantageous flexibility with regard to the products which can be prepared. The long batch times required lead to increased production costs. There is a risk of contamination since the plants have to be emptied and charged frequently. The risk of contamination can be limited by keeping the product temperatures low. This is achieved by using cold aqueous phases. Alternatively, a heat exchanger can also be connected downstream. In most cases, relatively large amounts of air are introduced into the system, which is undesirable.
[0006] Known continuous processes are characterized in that the individual phases are metered into a high-performance emulsifying device at the same time. The emulsification and homogenization operation takes place therein with a high input of energy, giving rise to high shear forces. However, the occurrence of high shear forces is able to damage polymers present in the preparations. As a result of simultaneously metering all of the components, they are subjected to relatively high temperatures over prolonged periods. As a result, the use of temperature-sensitive substances is only possible to a limited degree. Such substances are, for example, cosmetic active and functional ingredients, such as fragrances, vitamins, coenzymes, peptides, enzymes, nucleic acids, plant extracts, preservatives, such as, for example, those from 1,2-dibromo-2,4-dicyanobutane and 2-phenoxyethanol.
[0007] Although continuous plants with which it is possible to prepare a large number of different cosmetic and/or dermatological preparations are desired, they are not known to date. In particular, a plant with which it would be possible to prepare both low-viscosity emulsions, lotions, creams and body- and hair-cleansing preparations and also dishwashing detergents would represent a significant improvement in the prior art.
[0008] It has hitherto not been possible to prepare PIT emulsions in continuous processes since the droplets remain too large despite a high input of energy. Continuously prepared creams and liquid emulsions were in most cases insufficiently stable. During the preparation of preparations comprising washing-active substances, the use of continuous processes in most cases leads to inhomogeneities arising as a result of inadequate mixing. Transparent preparations are therefore only obtainable with difficulty since such inhomogeneities often lead to clouding. For the preparation of O/W emulsions, continuous processes have hitherto not been able to penetrate the market since it has not been possible to achieve products of high quality: in most cases the emulsions were not stable or tended towards oil losses. The cause of this behaviour is assumed to be the fact that homogeneous droplet size distributions cannot be achieved through the use of static mixers on their own.
[0009] The article “Eine Aniage zum kontinuierlichen Emulgieren” [A continuous emulsification plant] in the Journal Verfahrenstechnik, volume 1-2 from 1986 describes, for example, a continuous preparation process for the preparation of W/O and O/W creams. The discontinuously prepared preproducts pass through a metering system, a dynamic mixer and a static mixer. Here, a hot/cold process is realized in which the preproducts enter the process in cold or hot form. The emulsion is produced in the dynamic mixer, homogenization takes place in the static mixer, as a result of which the particle size distribution is adjusted. This plant is suitable for the preparation of skin creams, body lotions, mayonnaise and sauces.
[0010] In this process, the homogenization operation takes place at 40 to 75° C., although it would be desirable to carry out this step at low temperatures since temperature-sensitive constituents of the formulations, such as odour or aroma substances or active ingredients such as vitamins, should as far as possible not be subjected to thermal stress.
SUMMARY OF THE INVENTION
[0011] Starting from this, it was an object of the present invention to find a process which overcomes the disadvantages of the prior art.
[0012] It has been found, in a manner unforseen by the person skilled in the art, that a continuous preparation process, as shown in FIG. 1 , for cosmetic or dermatological preparations which comprise temperature-sensitive ingredients characterized by a sequence of the following process steps
(a) emulsification in mixing apparatuses ( 11 ), (b) establishing a mixture temperature of less than 40° C. by adding (B) aqueous phase with a lower temperature compared with the mixture, (c) addition (C) of perfume oil and/or temperature-sensitive active ingredients, (d) homogenization in apparatuses ( 13 ) in the temperature range from 20 to 50° C., particularly preferably 28 to 40° C., overcomes the disadvantages of the prior art. Likewise, a preparation process for cosmetic or dermatological preparations which comprise temperature-sensitive ingredients, as shown in FIG. 2 and characterized in that (1) it is carried out continuously and (2) by a sequence of the following process steps (a) emulsification in mixing apparatuses ( 30 ), in combination with static mixers ( 28 , 11 ) and/or homogenizers ( 29 , 33 ), (b) establishing a mixture temperature of 55-35° C. by adding (P,Q) aqueous phase of 15-50° C. with a lower temperature compared with the mixture, (c) addition (R,S) of perfume oil and/or temperature-sensitive active ingredients at different temperatures, (d) homogenization in apparatuses ( 29 , 33 ) in the temperature range from either 50 to 80° C., particularly preferably 60 to 70° C. or 20 to 50° C., particularly preferably 28 to 45° C., very particularly preferably 30 to 40° C., (e) stepwise (stagewise) cooling during the process ( 32 , 34 ), also remedies the disadvantages of the prior art. It is particularly preferred here when the entering preproducts have been heated beforehand to temperatures of from 40 to 100° C., particularly preferably 50 to 90° C.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] In this connection, it is preferred when, as a further downstream step ( 14 ), as shown in FIG. 1 or ( 32 , 34 ), as shown in FIG. 2 , the process product is cooled to at most 28 to 30° C. It is also preferred when the preproducts are mixed at temperatures of from 40 to 100° C., particularly preferably 50 to 90° C. before they enter the first mixing or homogenization apparatus. In addition, it is preferred when, upon passing through the homogenization apparatus ( 13 ), as shown in FIG. 1 , the temperature of the exiting mixture increases 2 to 60° C., or upon passing through the homogenization apparatus ( 29 , 33 ), as shown in FIG. 2 , the temperature of the exiting mixture increases 2 to 10° C., based on the temperature of the entering mixture.
[0025] It is particularly preferred when the emulsification operation is carried out in two different mixing apparatuses ( 10 ) and ( 11 ), as shown in FIG. 1 . It is very particularly preferred when the emulsification operation is carried out in a static mixer ( 10 ) and a loop mixer ( 11 ) ( FIG. 1 ) or ( 29 ) and ( 33 ) ( FIG. 2 ).
[0026] It is particularly preferred when the homogenization operation is carried out in a loop mixer ( 30 ) and a homogenizer ( 33 ), as shown in FIG. 2 .
[0027] It is particularly preferred when the homogenization operation is carried out in two different apparatuses ( 12 ) and ( 13 ), as shown in FIG. 1 . It is very particularly preferred when the homogenization operation is carried out in a static mixer ( 12 ) and a homogenizer ( 13 ).
[0028] It is very particularly preferred when the emulsification operation is carried out in a loop mixer ( 30 ) in combination with one or more homogenizers ( 29 , 33 ), and static mixers ( 28 , 31 ), as shown in FIG. 2 .
[0029] The invention also covers emulsions, PIT emulsions and products comprising washing-active substances, obtainable by a process according to at least one of the variants described. Preferably, such emulsions, PIT emulsions and products comprising washing-active substances comprise, or are used in such processes as, temperature-sensitive ingredients, such as fragrances, vitamins, coenzymes, peptides, enzymes, nucleic acids, plant extracts, preservatives.
[0030] Through the process according to the invention it is possible to achieve particularly high throughput capacities of the plants used: to date, the capacity limits of customary plants were 3 t/h, whereas with the plant according to the invention up to 10 t/h can be achieved. In this regard, the process is very universally suitable for completely different types of product groups: besides W/O and O/W emulsions, PIT emulsions and products comprising washing-active substances can also be prepared in a particularly cost-effective manner on one and the same plant, the products being particularly stable and also storable over long periods. In view of the universal applicability of the plant, production may be at particularly low cost. In the case of PIT emulsions, particularly small droplet sizes can be achieved which can otherwise only be prepared in long-term storage-stable form in laboratory experiments.
[0031] This is of great advantage particularly when sunscreen formulations based on PIT emulsions are to be prepared: in this way, it is possible to incorporate a particularly large amount of photoprotective agent and thus achieve particularly high sun protection factors of up to 40 and above.
[0032] It is advantageous in the process according to the invention to use as loop mixer an apparatus which is characterized by a product feed arranged at a distance from the product discharge, a conveying device such as a multi-threaded conveying screw, which is located in an internal guide tube, the mixing of the product being effected as a result of the volume conveyed through the internal conveying device being a multiple of the volume introduced through the feed, giving rise to forced circulation outside the guide tube against the conveyance direction within the guide tube. It is particularly preferred to use a mixer of the Burdosa DMT 320 model. Such mixers have hitherto been used to prepare orange juice concentrate, yoghurt, salad sauces or other foods and allow the process parameters to be matched in a very variable manner to the requirements. For example, besides a pure mixer operation, emulsification or foaming are also possible.
[0033] It is advantageous in the process according to the invention to use as further mixer an apparatus which acts at the same time as a homogenizer. A homogenizer of the Becomix DH 500 model, Berents, Stuhr, Germany is preferably used. It is particularly advantageous to use a high-pressure homogenizer consisting of a high-pressure pump, a structured packing and a valve, as is described, for example, in European patent application 810025.
[0034] It is further advantageous, instead of the mixer ( 10 ), to use a combination of two mixing apparatuses, in particular a static mixer and a dynamic mixer. In this case, the temperature of the exiting mixture increases on passing through the combination of mixing apparatuses by 2 to 60° C., based on the temperature of the entering mixture.
[0035] As a result of high-pressure homogenization, heating in a separate process step is particularly advantageously superfluous since, as a result of the input of energy for the homogenization, the homogenized material is very effectively heated simultaneously.
[0036] A further advantage of the process according to the invention is the property that it is very easy to clean the plant when changing the product. A cleaning solution is fed in and circulated in a suitable manner, thus dispensing with dismantling or laborious cleaning in some other way. Such apparatuses are also referred to as cip-capable (clean in process).
[0037] The examples below are intended to illustrate the present invention without limiting it. The numerical values in the examples are percentages by weight, based on the total weight of the particular preparations.
EXAMPLES
[0038] Examples (1) to (5) relate to FIG. 1 , and Examples (6) to (10) relate to FIG. 2 . In FIG. 2 , 28 =static mixer, 29 =Beco homogenizer, 30 =loop mixer, 31 =static mixer, 32 =heat exchanger, 33 =Beco homogenizer, 34 =heat exchanger
[0039] (1) Preparation of a Cream Containing Active Ingredient
Container 2 44.168 Demineralized water 7.500 Glycerol 0.200 Sodium hydroxide solution 45% Container 1 3.000 Glyceryl stearate citrate 2.000 Caprylic/capric triglyceride 2.000 Tridecyl stearate 1.100 Stearyl alcohol 1.100 Cetyl alcohol 1.500 Hydrogenated coconut fatty glycerides 0.010 Ceramide 3 Cold water 20.270 Demineralized water Container 4 3.000 Dicaprylyl ether 0.400 Carbomer Container 3 0.002 Ubiquinone 10.000 Cyclomethicone Container 5 3.000 Ethanol 0.500 Preservatives 0.250 Perfume
[0040] Firstly, the following phases are introduced into mixing containers: in mixing container ( 1 ) an oil phase heated to 60 to 95° C., in mixing container ( 2 ) a water phase heated to 80° C., in mixing container ( 3 ) an electrolyte-containing phase, in mixing container ( 4 ) a carbomer phase and in mixing container ( 5 ) a phase comprising perfume oil and active ingredients. Metering from the mixing containers is continuous. The oil phase from mixing container ( 1 ) is firstly combined with the water phase from mixing container ( 2 ), then the active-ingredient-containing phase from mixing container ( 3 ) and the carbomer phase from mixing container ( 4 ) are added. The mixture passes through a static inline mixer ( 10 ) model MS2G, Bran+Luebbe and is then emulsified in a loop mixer ( 11 ) model Burdosa DMT 320 at 500 revolutions per minute. The exiting emulsion has a temperature of 53.1° C., is cooled suddenly to 35-38° C. at point (B) with cold water, and the phase comprising perfume oil and active ingredients is added from mixing container ( 5 ) at point (C). After passing through a further static mixer ( 12 ), model MS2G Bran+Luebbe, the emulsion is homogenized in a homogenizer ( 13 ) model Becomix DH 500, Berents, where the temperature increases by 2 to 10° C. Cooling to 30° C. then takes place via heat exchanger ( 14 ) and the product is drawn off. A throughput of 2 t/h is achieved.
[0041] (2) Preparation of a Soft Cream
Container 1 1.500 Paraffin oil 2.500 Stearic acid 2.000 Petrolatum 3.500 Myristyl alcohol 1.500 Myristyl myristate 1.200 Glyceryl stearate 1.000 Hydrogenated coconut fatty glycerides 0.100 Cetyl phosphate 0.350 Preservatives Container 2 23.630 Demineralized water 3.500 Glycerol Container 3 4.800 Demineralized water 0.600 Sodium hydroxide solution 45% Container 4 0.750 Dimethicone 0.300 Carbomer 18.750 Demineralized water 2.800 Ethanol, denatured Container 5 0.500 Tocopheryl acetate 0.350 Polyglyceryl-2 caprate 0.200 Ethanol 0.170 Perfume Cold water 30.000 Demineralized water
[0042] Firstly, the following phases are introduced into mixing containers: in mixing container ( 1 ) an oil phase heated to 60 to 95° C., in mixing container ( 2 ) a water phase heated to 80° C., in mixing container ( 3 ) an NaOH-containing phase, in mixing container ( 4 ) a carbomer phase and in mixing container ( 5 ) a phase comprising perfume oil and active ingredients. Metering from the mixing containers is continuous. The oil phase from mixing container ( 1 ) is firstly combined with the water phase from mixing container ( 2 ), then the water phase from mixing container ( 2 ), NaOH-containing phase from mixing container ( 3 ) and the carbomer phase from mixing container ( 4 ) are added. The mixture passes through a static inline mixer ( 10 ) model MS2G, Bran+Luebbe and is then emulsified in a loop mixer ( 11 ) model Burdosa DMT 320 at 1400 revolutions per minute. During this, the temperature increases to 46.3° C. The exiting emulsion is cooled suddenly to 31.1° C. at point (B) with cold water, and the phase comprising perfume oil and active ingredients is added from mixing container ( 5 ) at point (C). After passing through a further static mixer ( 12 ), model MS2G Bran+Luebbe, the emulsion is homogenized in the homogenizer ( 13 ) model Becomix DH 500, Berents, where the temperature increases to 46.9° C. Cooling to 30° C. is then carried out via heat exchanger ( 14 ) and the product is drawn off. A throughput of 3.2 t/h is achieved.
[0043] (3) Preparation of a Skincare Liquid Soap
Container 1 3.000 Cocoamidopropylbetaine 0.500 Citric acid 0.300 PEG-40 hydrogenated castor oil Container 2 7.000 Demineralized water 1.000 Trisodium EDTA 20% strength solution 0.500 Acrylate copolymer 0.450 Sodium benzoate 0.800 PEG-200 hydrogenated glyceryl palm oil fatty acid ester 4.000 Disodium coconut fatty acid glutamate Container 3 6.101 Demineralized water 2.000 Sodium chloride Container 4 25.000 Sodium laureth sulphate Container 5 4.350 Cocoamidopropylbetaine 0.300 Perfume 2.000 Decyl polyglucose Cold water 6.000 Demineralized water 2.000 Sodium chloride
[0044] Firstly, the following phases are introduced into mixing containers: in mixing container ( 1 ) an oil phase heated to 40° C., in mixing container ( 2 ) a water phase heated to 40° C., in mixing container ( 3 ) an electrolyte-containing phase, in mixing container ( 4 ) liquid lauryl ether sulphate and in mixing container ( 5 ) a phase comprising perfume oil and active ingredients. Metering from the mixing containers is continuous. The oil phase from mixing container ( 1 ) is firstly combined with the water phase from mixing container ( 2 ), then the water phase from mixing container ( 2 ), electrolyte-containing phase from mixing container ( 3 ) and the liquid lauryl ether sulphate from mixing container ( 4 ) are added. The mixture passes through a static inline mixer ( 10 ) model MS2G, Bran+Luebbe and is then emulsified in a loop mixer ( 11 ) model Burdosa DMT 320 at 150 revolutions per minute. During this, the temperature increases to 22.2° C. The exiting emulsion is cooled suddenly to 18° C. at point (C) with cold water, and the phase comprising perfume oil and active ingredients is added from mixing container ( 5 ) at point (C). After passing through a further static mixer ( 12 ), model MS2G, Bran+Luebbe, the washing-active product is homogenized in a homogenizer ( 13 ) model Becomix DH 500, Berents, where the temperature increases to 20.9° C. The product is then drawn off. A throughput of 2.5 t/h is achieved.
[0045] (4) Preparation of a Sunscreen Spray (PIT Emulsion)
Container 1 5.400 Glyceryl stearate + ceteareth-20 + ceteareth- 12 + cetearyl alcohol 3.000 Tridecyl stearate (+) tridecyl trimellitate 3.300 C12-C15 alkyl benzoate 0.500 PVP/hexadecene copolymer 5.000 Octyl methoxycinnamate 2.600 Ceteareth-20 2.000 Octyltriazone 1.000 Diethylhexylbutamidotriazone 1.000 Dicaprylyl ether Container 2 32.15 Demineralized water 5.000 Glycerol Container 3 7.800 Demineralized water 0.150 Sodium hydroxide solution 45% 0.500 Phenylbenzimidazolesulphonic acid Container 4 2.000 Demineralized water 0.400 DMDM hydantoin Container 5 0.400 Preservatives 0.500 Tocopheryl acetate 0.300 Perfume Cold water 27.000 Demineralized water
[0046] Firstly, the following phases are introduced into mixing containers: in mixing container ( 1 ) an oil phase heated to 60 to 95° C., in mixing container ( 2 ) a water phase heated to 60 to 95° C., in mixing container ( 3 ) an electrolyte-containing phase, in mixing container ( 4 ) a preservative phase and in mixing container ( 5 ) a phase comprising perfume oil and active ingredients. Metering from the mixing containers is continuous. The oil phase from mixing container ( 1 ) is firstly combined with the water phase from mixing container ( 2 ), then the water phase from mixing container ( 2 ), electrolyte-containing phase from mixing container ( 3 ) and the preservative phase from mixing container ( 4 ) are added. The mixture passes through a static inline mixer ( 10 ) model MS2G, Bran+Luebbe and is then emulsified in a loop mixer ( 11 ) model Burdosa DMT 320 at 1000 revolutions per minute. The exiting emulsion has a temperature of 93.1° C., is cooled suddenly to 61.2° C. at point (B) with cold water, and the phase comprising perfume oil and active ingredients from mixing container ( 5 ) is added at point (C). After passing through a further static mixer ( 12 ), model MS2G, Bran+Luebbe, the emulsion is homogenized in a homogenizer ( 13 ) model Becomix DH 500, Berents, where the temperature increases by 2 to 10° C. Cooling to 28.6° C. is then carried out by heat exchanger ( 14 ) and the product is drawn off. The product has a droplet size of 103.5 nm. A throughput of 3.5 t/h is achieved.
[0047] (5) Preparation of a Sun Milk
Container 1 5.500 C12-C15 alkyl benzoate 4.160 Glyceryl stearate self-emulsifying 2.500 Caprylic/capric triglyceride 2.240 Stearic acid 0.750 Cetearyl ether 3.000 Octyltriazone 2.500 Tocopheryl acetate 5.500 Octyl methoxycinnamate 1.000 Titanium dioxide Container 2 14.806 Demineralized water 7.500 Glycerol 2.500 Butylene glycol 0.044 Sodium hydroxide solution 45% Container 3 19.300 Demineralized water 2.000 Dicaprylyl ether 0.500 Xanthan gum Container 5 3.500 Ethanol 0.300 Preservatives 2.000 Capryl/capric triglyceride 0.400 Perfume Cold water 20.000 Demineralized water
[0048] Firstly, the following phases are introduced into mixing containers: in mixing container ( 1 ) an oil phase heated to 60 to 95° C., in mixing container ( 2 ) a water phase heated to 80° C., in mixing container ( 3 ) a thickener phase and in mixing container ( 5 ) a phase comprising perfume oil and active ingredients. Metering from the mixing containers is continuous. The oil phase from mixing container ( 1 ) is firstly combined with the water phase from mixing container ( 2 ), then the water phase from mixing container ( 2 ), and the thickener phase from mixing container ( 3 ) are added. The mixture passes through a static inline mixer ( 10 ) model MS2G, Bran+Luebbe and is then emulsified in a loop mixer ( 11 ) model Burdosa DMT 320 at 1000 revolutions per minute. The exiting emulsion has a temperature of 46.2° C., is cooled suddenly to 35-38° C. at point (B) with cold water, and the phase comprising perfume oil and active ingredients from mixing container ( 5 ) is added at point (C). After passing through a further static mixer ( 12 ), model MS2G Bran+Luebbe, the emulsion is homogenized in a homogenizer ( 13 ) model Becomix DH 500, Berents, where the temperature increases by 7 to 11° C. Cooling to 30° C. is then carried out by heat exchanger ( 14 ) and the product is drawn off. A throughput of 2 t/h is achieved.
[0049] (6) Preparation of a Cream Containing Active Ingredient
Container 2 45.178 Demineralized water 7.500 Glycerol 0.200 Sodium hydroxide solution 45% Container 1 3.000 Glyceryl stearate citrate 4.000 Caprylic/capric triglyceride 2.600 Cetyl alcohol Cold water 20.270 Demineralized water Container 4 3.000 Dicaprylyl ether 0.400 Carbomer Container 3 0.002 Active ingredients 10.000 Cyclomethicone Container 5 3.100 Ethanol 0.500 Preservatives 0.250 Perfume
[0050] Firstly, the following phases are introduced into mixing containers: in mixing container ( 21 ) an oil phase heated to 60 to 95° C., in mixing container ( 22 ) a water phase heated to 60 to 80° C., in mixing container ( 23 ) an electrolyte-containing phase, in mixing container ( 24 ) a carbomer phase and in mixing container ( 25 ) a phase comprising perfume oil and active ingredients. Metering from the mixing containers is continuous. The oil phase from mixing container ( 21 ) is firstly combined with the water phase from mixing container ( 22 ), and passes through a static inline mixer ( 28 ) model MS2G, Bran+Luebbe, then the active-ingredient-containing phase from mixing container ( 23 ) and the carbomer phase from mixing container ( 24 ) are added. The mixture passes through the homogenizer model Becomix DH 500, Berents ( 29 ) with 800 revolutions per minute and is then emulsified in a loop mixer ( 30 ) model Burdosa DMT 320 at 500 revolutions per minute. The exiting emulsion has a temperature of 53.1° C., is cooled suddenly to 35-38° C. at point (Q) with cold water. After passing through a further static mixer ( 31 ), model MS2G, Bran+Luebbe and cooling to 31° C. in the heat exchanger ( 32 ), the phase comprising perfume oil and active ingredients from mixing container ( 25 ) is added at point (S). The emulsion is then homogenized in a homogenizer ( 33 ) model Becomix DH 500, Berents, with 2000 revolutions per minute, where the temperature increases by 2 to 10° C. Cooling to 28° C. is then carried out by heat exchanger ( 34 ) and the product is drawn off. A throughput of 6 t/h is achieved.
[0051] (7) Preparation of a Soft Cream
Container 1 3.500 Paraffin oil 1.500 Stearic acid 0.500 Myristyl myristate 1.100 Hydrogenated coconut fatty glycerides 0.350 Preservatives Container 2 29.130 Demineralized water 3.500 Glycerol Container 3 6.000 Demineralized water 0.600 Sodium hydroxide solution 45% Container 4 0.750 Dimethicone 0.300 Carbomer 18.750 Demineralized water 2.800 Ethanol, denatured Container 5 0.500 Actives 0.350 Silicone oil 0.200 Ethanol 0.170 Perfume Cold water 30.000 Demineralized water
[0052] Firstly, the following phases are introduced into mixing containers: in mixing container ( 21 ), an oil phase heated to 60 to 95° C., in mixing container ( 22 ) a water phase heated to 80° C., in mixing container ( 23 ) an NaOH-containing phase, in mixing container ( 24 ) a carbomer phase and in mixing container ( 25 ) a phase comprising perfume oil and active ingredients. Metering from the mixing containers is continuous.
[0053] The oil phase from mixing container ( 21 ) is firstly combined with the water phase from mixing container ( 22 ), and passes through a static inline mixer ( 28 ) model MS2G, Bran+Luebbe, then the NaOH-containing phase from mixing container ( 23 ) and the carbomer phase from mixing container ( 24 ) are added. Shortly before the homogenizer ( 29 ) model Becomix DH 500, Berents, cooling is carried out suddenly to 38-41° C. at point (P) with cold water. The mixture passes through the homogenizer model Becomix DH 500, Berents at 1000 revolutions ( 29 ) and is then emulsified in a loop mixer ( 30 ) model Burdosa DMT 320 at 1400 revolutions per minute. During this, a temperature of 42.3° C. Is established. After passing through a further static mixer ( 31 ), model MS2G, Bran+Luebbe and cooling in heat exchanger ( 32 ), the phase comprising perfume oil and active ingredients from mixing container ( 25 ) is added at point (R). The emulsion is then homogenized in an homogenizer ( 33 ) model Becomix DH 500, Berents, with 1000 revolutions per minute, where the temperature increases by 2 to 10° C. Cooling to 30° C. is then carried out by heat exchanger ( 34 ), and the product is drawn off. A throughput of t/h is achieved.
[0054] (8) Preparation of a Skincare Liquid Soap
Container 1 3.500 Cocoamidopropylbetaine 0.300 PEG-40 hydrogenated castor oil Container 2 8.000 Demineralized water 0.500 Acrylate copolymer 0.450 Preservatives 4.800 Disodium coconut fatty acid glutamate Container 3 6.101 Demineralized water 2.000 Sodium chloride Container 4 25.000 Sodium laureth sulphate Container 5 6.350 Cocamidopropylbetaine 0.300 Perfume Cold water 40.699 Demineralized water
[0055] Firstly, the following phases are introduced into mixing containers: in mixing container ( 21 ) an oil phase heated to 40° C., in mixing container ( 22 ) a water phase heated to 40° C., in mixing container ( 23 ) an electrolyte-containing phase, in mixing container ( 24 ) liquid lauryl ether sulphate and in mixing container ( 25 ) a phase comprising perfume oil and active ingredients. Metering from the mixing containers is continuous. The oil phase from mixing container ( 21 ) is firstly combined with the water phase from mixing container ( 22 ) and passes through a static inline mixer ( 28 ) model MS2G, Bran+Luebbe, then the electrolyte-containing phase from mixing container ( 23 ) and liquid lauryl ether sulphate from mixing container ( 24 ) are added. The mixture passes through the homogenizer model Becomix DH 500, Berents ( 29 ) at just 500 revolutions per minute and is then mixed intensively in a loop mixer ( 30 ) model Burdosa DMT 320 at 1000 revolutions per minute. During this, the temperature increases to 22.2° C. The exiting emulsion is cooled suddenly to 18° C. at point (Q) with cold water, and the phase comprising perfume oil and active ingredients from mixing container ( 25 ) is added at point (R). After passing through a further static mixer ( 31 ), model MS2G, Bran+Luebbe, the phase comprising perfume oil and active ingredients from mixing container ( 25 ) is added at point (S). The heat exchangers ( 32 , 34 ) have no function here. Finally, the washing-active product is homogenized in a homogenizer ( 33 ) model Becomix DH 500, Berents, with 1000 revolutions per minute, where the temperature increases to 20.9° C. The product is then drawn off. A throughput of 8 t/h is achieved.
[0056] (9) Preparation of a Sunscreen Spray (PIT Emulsion)
Container 1 5.400 Glyceryl stearate + Ceteareth-20 + Ceteareth- 12 + cetearyl alcohol 3.000 Tridecyl stearate (+) tridecyl trimellitate 3.300 C12-15 alkyl benzoate 3.100 Paraffin oil 7.000 Octyl methoxycinnamate 1.000 Diethylhexylbutamidotriazone Container 2 33.15 Demineralized water 5.000 Glycerol Container 3 7.800 Demineralized water 0.150 Sodium hydroxide solution 45% 0.500 Phenylbenzimidazolesulphonic acid Container 4 2.000 Demineralized water 0.400 Preservatives Container 5 0.400 Preservatives 0.500 Active ingredients 0.300 Perfume Cold water 27.000 Demineralized water
[0057] Firstly, the following phases are introduced into mixing containers: in mixing container ( 21 ) an oil phase heated to 60 to 95° C., in mixing container ( 22 ) a water phase heated to 60 to 95° C., in mixing container ( 23 ) an electrolyte-containing phase, in mixing container ( 24 ) a preservative phase and in mixing container ( 25 ) a phase comprising perfume oil and active ingredients. Metering from the mixing containers is continuous. The oil phase from mixing container ( 21 ) is firstly combined with the water phase from mixing container ( 22 ), and passes through a static inline mixer ( 28 ) model MS2G, Bran+Luebbe, then the electrolyte-containing phase from mixing container ( 23 ) and preservative phase from mixing container ( 24 ) are added. The mixture passes through the homogenizer model Becomix DH 500, Berents ( 29 ), although it is switched off for this type of emulsion. The emulsion is then emulsified in a loop mixer ( 31 ) model Burdosa DMT 320 at 1000 revolutions per minute. The exiting emulsion has a temperature of 93.1° C. and is cooled suddenly to 61.2° C. at point (Q) with cold water. The mixture passes through a static inline mixer ( 30 ) model MS2G, Bran+Luebbe and then the phase comprising perfume oil and active ingredients from mixing container ( 25 ) is added at point (R). After passing through a heat exchanger ( 32 ), where the temperature adjusts to 38° C., the emulsion is homogenized in a homogenizer ( 33 ) model Becomix DH 500, Berents, at 500 revolutions per minute, during which the temperature does not increase. Cooling to 28.6° C. is then carried out by heat exchanger ( 34 ) and the product is drawn off. The product has a particle size of 103.5 nm. A throughput of 7 t/h is achieved.
[0058] (10) Preparation of a Sun Milk
Container 1 8.500 Paraffin oil 4.160 Glyceryl stearate self-emulsifying 2.500 Caprylic/capric triglyceride 2.240 Stearic acid 0.750 Cetearyl alcohol 2.500 Active ingredients 5.500 Octyl methoxycinnamate 1.000 Titanium dioxide Container 2 22.306 Demineralized water 2.500 Butylene glycol 0.044 Sodium hydroxide solution 45% Container 3 19.300 Demineralized water 2.000 Dicaprylyl ether 0.500 Xanthan gum Container 5 3.500 Ethanol 0.300 Preservatives 2.000 Caprylic/capric triglyceride 0.400 Perfume Cold water 20.000 Demineralized water
[0059] Firstly, the following phases are introduced into mixing containers: in mixing container ( 21 ) an oil phase heated to 60 to 95° C., in mixing container ( 22 ) a water phase heated to 60 to 80° C., in mixing container ( 23 ) a thickener phase and in mixing container ( 25 ) a phase comprising perfume oil and active ingredients. Metering from the mixing containers is continuous. The oil phase from mixing container ( 21 ) is firstly combined with the water phase from mixing container ( 22 ) and passes through a static inline mixer ( 28 ) model MS2G, Bran+Luebbe, then the thickener phase from mixing container ( 23 ) is added. The mixture passes through the homogenizer model Becomix DH 500, Berents with 1200 revolutions per minute ( 29 ) and is then emulsified in a loop mixer ( 30 ) model Burdosa DMT 320 at 1200 revolutions per minute. The exiting emulsion has a temperature of 46.2° C. and is cooled suddenly to 35-38° C. at point (Q) with cold water. After passing through a further static mixer ( 31 ), model MS2G, Bran+Luebbe and cooling in the heat exchanger ( 32 ), the phase comprising perfume oil and active ingredients from mixing container ( 25 ) is added at point (S). The emulsion is then homogenized in a homogenizer ( 13 ) model Becomix DH 500, Berents, at 2000 revolutions per minute, during which the temperature increases by 2 to 10° C. Cooling to 30° C. is then carried out by heat exchanger ( 14 ) and the product is drawn off. A throughput of 6 t/h is achieved.
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The invention is a continuous process for preparing a cosmetic or dermatological preparation, comprising emulsifying at least two pre-products in at least one mixing apparatus, cooling the emulsion to less than 40° C. by adding an aqueous phase with a lower temperature than the mixture, adding at least one ingredient selected from the group consisting of perfume oil and temperature-sensitive active ingredients, and homogenizing the emulsion in at least one homogenizing apparatus at a temperature of from 20 to 50° C. The invention also includes a product made by such process.
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FIELD OF THE INVENTION
[0001] The invention relates to a process for obtaining 3-(2-hydroxy-5-methylphenyl)-N,N-diisopropyl-3-phenylpropylamine, its enantiomers or mixtures thereof, or its pharmaceutically acceptable salts, as well as to a new compound useful for the synthesis of said compounds.
BACKGROUND OF THE INVENTION
[0002] Tolterodine, the generic name of the compound (R)-3-(2-hydroxy-5-methylphenyl)-N,N-diisopropyl-3-phenylpropylamine, occasionally identified as (R)-tolterodine, is a muscarinic receptor antagonist useful in the treatment of urinary incontinence and other symptoms of urinary bladder hyperactivity. The (S) enantiomer, also known as (S)-tolterodine, and its use in treating urinary and gastrointestinal disorders, has been disclosed in patent document WO 98/03067. U.S. Pat. No. 6,538,035 discloses the use of tolterodine and some of its derivatives in treating asthma in mammals.
[0003] Tolterodine was first disclosed in U.S. Pat. No. 5,382,600. Said patent discloses several methods for preparing tolterodine and analogues, generally based on displacing a tosylate with diisopropylamine. Said process has several drawbacks. The displacement reaction occurs very slowly, so several days are required to carry out said reaction, and the total yields are low. Some of the reagents used, such as methyl iodide and lithium and aluminum hydride, are expensive and their use implies a hazard. This makes the overall process more expensive and rather unproductive.
[0004] An alternative process for obtaining tolterodine is disclosed in U.S. Pat. No. 5,922,914. Said process comprises reducing 3,4-dihydro-6-methyl-4-phenyl-2H-benzopyran-2-one with DIBAL (diisobutylaluminum hydride) in toluene to give the corresponding hemiketal 6-methyl-4-phenyl-3,4-dihydro-2H-1-benzopyran-2-ol which is then subjected to reductive amination to give racemic tolterodine. This process also has some disadvantages since it uses the reagent DIBAL, which is expensive and hazardous, so carrying out the invention to practice is not suitable at the industrial level.
[0005] Patent application WO 03/014060 discloses a process for obtaining tolterodine which, though it partially overcomes some drawbacks of the previous processes, it still includes problematic steps, particularly obtaining the intermediate 3-(2-methoxy-5-methylphenyl)-3-phenylpropanol, its conversion into the tosylate derivative and the subsequent displacement of tosylate with diisopropylamine. These steps still have serious problems, such as the steric hindrance of diisopropylamine in the tosylate displacement reaction, which makes the nucleophilic substitution reaction more difficult, the high temperatures needed for the same, as well as the long reaction times they comprise, even days.
[0006] A different approach for preparing the (R)-tolterodine enantiomer consists of several enantioselective syntheses such as those disclosed in U.S. Pat. No. 6,310,248, or by Andersson et al. in J. Org. Chem. 1998, 63, 8067-8070, which disclose processes requiring the participation of asymmetry inducers or chiral auxiliaries, respectively, which are generally very expensive reagents.
[0007] It is therefore necessary to solve the problems associated with processes belonging to the state of the art and to provide an alternative process for obtaining tolterodine which improves the cost of the process using more cost-effective and less hazardous reagents and starting materials and which is therefore more productive. Said process must advantageously be susceptible to applying on an industrial scale and must provide the desired product with a good yield and quality.
SUMMARY OF THE INVENTION
[0008] The invention is faced with the problem of providing an alternative process for obtaining tolterodine which overcomes all or part of the previously mentioned drawbacks.
[0009] The solution provided by the invention is based on the fact that the inventors have observed that it is possible to obtain 3-(2-hydroxy-5-methylphenyl)-N,N-diisopropyl-3-phenylpropylamine, its enantiomers or mixtures thereof, or its pharmaceutically acceptable salts, from a compound of formula (II) (defined below) yielding, by reductive amination with diisopropylamine in the presence of a reducing agent and the subsequent deprotection of the hydroxyl, said compounds in very good yield. In a particular embodiment, the intermediate resulting from reductive amination [compound of formula (III) (defined below)] is converted into a salt, and if so desired said salt is isolated before removing the hydroxy protecting group. Said compound of formula (II) can be obtained from commercial, cost-effective starting compounds.
[0010] A process such as the one provided by this invention has the advantage that the chemical reactions involved occur with high yields, with short reaction times, typically less than those required in other processes in the state of the art, without involving an increase in the number of synthesis steps with respect to the existing processes. Furthermore, if the compound of formula (III) is isolated in the form of a salt, for example hydrobromide, before removing the hydroxyl protecting group, a substantially pure product is obtained constituting the starting material to obtain, by means of hydrolysis of the hydroxyl protecting group, 3-(2-hydroxy-5-methylphenyl)-N,N-diisopropyl-3-phenylpropylamine, its enantiomers or mixtures thereof, or its pharmaceutically acceptable salts, with a high purity and yield. Nor does said process require the use of expensive and/or hazardous reagents and provides 3-(2-hydroxy-5-methylphenyl)-N,N-diisopropyl-3-phenylpropylamine, its enantiomers or mixtures thereof, or its pharmaceutically acceptable salts, particularly (R)-tolterodine, with good yield and pharmaceutical quality. This all contributes to reducing the overall cost of the process, making it commercially interesting and allowing carrying it out to practice on an industrial level.
[0011] Therefore one aspect of the invention consists in a process for obtaining 3-(2-hydroxy-5-methylphenyl)-N,N-diisopropyl-3-phenylpropylamine, from a compound of formula (II). Resolution of the compound 3-(2-hydroxy-5-methyl-phenyl)-N,N-diisopropyl-3-phenylpropylamine at its (R) enantiomer yields therapeutically useful (R)-tolterodine.
[0012] An additional aspect of this invention consists in a compound of formula (II) and its use in obtaining 3-(2-hydroxy-5-methylphenyl)-N,N-diisopropyl-3-phenylpropylamine, its enantiomers (R) and (S) or mixtures thereof, or its pharmaceutically acceptable salts.
[0013] Another additional aspect of this invention consists in a process for obtaining said compound of formula (II).
[0014] Another additional aspect of this invention consists in a salt of a compound of formula (III) and its use in obtaining 3-(2-hydroxy-5-methylphenyl)-N,N-diisopropyl-3-phenylpropylamine, its enantiomers (R) and (S) or mixtures thereof, or its pharmaceutically acceptable salts. In a particular embodiment, said salt is an inorganic acid addition salt, such as hydrobromide.
[0015] Another additional aspect of this invention consists in a process for obtaining said salt of the compound of formula (III).
DETAILED DESCRIPTION OF THE INVENTION
[0016] In one aspect, the invention provides a process for obtaining 3-(2-hydroxy-5-methylphenyl)-N,N-diisopropyl-3-phenylpropylamine of formula (I)
[0017] wherein the asterisk indicates an asymmetrical carbon atom;
[0000] its enantiomers or mixtures thereof, or its pharmaceutically acceptable salts, comprising:
[0018] (a) reacting compound of formula (II)
[0019] wherein R is a hydroxyl protecting group and the asterisk has the previously indicated meaning;
with diisopropylamine in the presence of a reducing agent to give a compound of formula (III)
[0020] wherein (R) and the asterisk have the previously indicated meanings;
[0021] (b) removing the hydroxyl protecting group from the compound of formula (III) to obtain the compound of formula (I); and
[0022] (c) if so desired, separating the desired (R) or (S) enantiomer, or the mixture of enantiomers, and/or converting the compound of formula (I) into a pharmaceutically acceptable salt thereof.
[0023] In a particular embodiment, the intermediate of formula (III) is converted into a salt, and if so desired is isolated before removing the hydroxyl protecting group [step (b)].
[0024] The starting product, compound of formula (II), is a new compound that can be obtained by means of a process such as the one described below.
[0025] As it is used in this description, the term “hydroxyl protecting group” includes any group capable of protecting a hydroxyl group. Examples of hydroxyl group protecting groups have been disclosed by Green T W et al. in “Protective groups in Organic Synthesis”, 3 rd Edition (1999), Ed. John Wiley & Sons (ISBN 0-471-16019-9). Though virtually any hydroxyl protecting group can be used, in a particular embodiment the hydroxyl protecting group is a C 1 -C 4 alkyl group, an optionally substituted benzyl group, aralkyl, silyl ether, carbonate or benzyl ester. The term “C 1 -C 4 alkyl” refers to a radical derivative of a linear or branched alkane with 1 to 4 carbon atoms, for example, methyl, ethyl, n-propyl, iso-propyl, n-butyl, t-butyl, etc. In a particular embodiment, the hydroxyl protecting group is a C 1 -C 4 alkyl group, preferably methyl or a benzyl group.
[0026] The reaction of the compounds of formula (II) with diisopropylamine in the presence of a reducing agent constitutes a reductive amination. Though virtually any suitable reducing agent can be used in said reaction, in a particular embodiment when R is methyl, the reducing agent is selected from NaBCNH 3 and NaB(AcO) 3 H, preferably NaB(AcO) 3 H, or alternatively, the reduction is carried out by means of hydrogenation in the presence of the suitable catalyst, for example an optionally supported metal catalyst, such as Pd/C, etc. This reaction is carried out in an organic solvent, such as an ether, for example tetrahydrofuran (THF), etc., a halogenated hydrocarbon, for example, dichloromethane, etc., an alcohol, for example, methanol, etc., acetonitrile, etc. Reductive amination occurs through the corresponding “immonium salt” intermediate and can be carried out either in two consecutive steps, ammonium salt formation and subsequent reduction, or in a single step (one-pot), both alternatives falling within the scope of this invention. Reductive amination occurs with a high yield, typically exceeding 90%, thus contributing to the high overall yield of the process of obtaining the compound of formula (I) provided by this invention. In a particular embodiment, when R in the compound of formula (II) is methyl, this reductive amination step is carried out at a temperature comprised between −20° C. and 40° C., preferably between 0° C. and 20° C.
[0027] The removal of the hydroxyl protecting group from the compound of formula (III) to obtain the compound of formula (I) can be carried out by conventional methods, for example by means of treating with mineral acids, Lewis acids, organic sulfides, etc. In a particular embodiment, when R in the compound of formula (III) is methyl, the removal of the hydroxyl protecting group is carried out by treating with aqueous hydrobromic acid in acetic acid, and optionally in the presence of a phase transfer catalyst, such as an alkylammonium halide, for example tetrabutylammonium bromide. This step is carried out at the suitable temperature, depending on the species involved, which may easily be determined by a person skilled in the art; in a particular embodiment, when R in the compound of formula (III) is methyl, the removal of said hydroxyl protecting group is carried out at a temperature comprised between 90° C. and 150° C., preferably between 110° C. and 120° C.
[0028] Alternatively, the intermediate of formula (III) can be converted into a salt which, if so desired, can be isolated before removing the hydroxyl protecting group [step (b)]. To that purpose, said compound of formula (III) is reacted with a suitable acid in a suitable solvent, such as an ester, an alcohol, etc., thereby forming the corresponding acid addition salt due to the presence of the amino group in said intermediate. Virtually any organic or inorganic acid can be used to form said salt of the compound of formula (III). In a particular embodiment, said acid is an inorganic acid. Illustrative non-limiting examples of said salts of the compound of formula (III) include hydrochloride, hydrobromide, sulfate, etc. Said salt will advantageously be a salt that can be isolated from the reaction medium, for example hydrobromide. The compound of formula (I) can be obtained from the salt of the compound of formula (III) by removal of the hydroxyl protecting group, which may be carried out by any of the previously mentioned methods in relation to the removal of the carboxyl protecting group in the compounds of formula (III). Advantageously, when the anion of the salt of the intermediate of formula (III) is a pharmaceutically acceptable anion, the product resulting from the removal of the hydroxyl protecting group may be a pharmaceutically acceptable salt of the compound of formula (I). Said product may be obtained with a high purity, which simplifies its purification to a pharmaceutical quality grade. Therefore, the isolation of the salt from the compound of formula (III) contributes to the purification of the intermediate of formula (III) since the impurities would remain in the reaction mother liquor, and accordingly, upon converting said intermediate into the compound of formula (I), a final product substantially free of impurities which virtually does not need subsequent purifications is obtained.
[0029] In a particular embodiment, the salt of the compound of formula (III) is N,N-diisopropyl-3-(2-methoxy-5-methylphenyl)-3-phenylpropylamine hydrobromide. Said acid addition salt can be obtained by reacting the compound of formula (III) with hydrobromic acid and acetic acid in a suitable organic solvent, such as ethyl acetate, isopropanol, isobutanol, etc. and maintaining the pH between 3 and 5, thereby precipitating said salt, which facilitates its isolation (Example 8). A substantially pure, i.e. virtually free of impurities, and stable solid is thus obtained, which may constitute the starting material for obtaining the compound of formula (I), its enantiomers or mixtures thereof, or its pharmaceutically acceptable salts, for example, hydrobromide, after removal of the hydroxyl protecting group. Using said N,N-diisopropyl-3-(2-methoxy-5-methylphenyl)-3-phenylpropylamine hydrobromide salt, the removal of the hydroxyl protecting group by means of hydrolysis with hydrobromic and acetic acid occurs at short reaction times (typically in 4-6 hours compared to 2-3 days used in other processes), obtaining as a resulting product the hydrobromide of the compound of formula (I), a pharmaceutically acceptable salt, with a high purity, typically with a purity exceeding 99.5%, thus being just a simple purification necessary, for example with methanol, to obtain a final product with a purity of 99.8% or more.
[0030] The compound of formula (I) is an amine and can form addition salts with organic or inorganic acids when it reacts with the suitable acids. Examples of said salts include hydrochloride, hydrobromide, sulfate, methanesulfonate, phosphate, nitrate, benzoate, citrate, tartrate, fumarate, maleate, (WO 98/29402). Said salts can be obtained by conventional methods by reacting the free amine with the mentioned acid. In a particular embodiment, said salt is a pharmaceutically acceptable salt, for example, hydrobromide. Said salt can be obtained either by reacting the free amine with hydrobromic acid or as a result of conducting removal of the hydroxyl protecting group by treating with hydrobromic acid. If so desired, said addition salt can optionally be converted into the corresponding free amine by conventional methods, for example by changing the pH of a solution comprising said salt until the free amine is obtained.
[0031] The compound of formula (I) has a chiral carbon. Therefore, the compound of formula (I) exists either in the form of its isolated (R) or (S) enantiomers or in the form of mixtures of said enantiomers. As it is used in this description, the term “mixtures” applied to enantiomers includes both racemic mixtures and mixtures enriched in any one of the enantiomers. The compound of formula (I) can be obtained from a mixture of enantiomers, such as a racemic mixture, of the compound of formula (II) or of the compound of formula (III) or of a salt thereof, or else from the pure enantiomers of said compounds of formula (II) or of formula (III) or of a salt thereof. When the starting material is a mixture of enantiomers, the obtained (R) and (S) enantiomers of the compound of formula (I) can be separated by conventional methods of resolution of mixtures of enantiomers, for example by means of fractional crystallization, conventional chromatographic methods, etc. In a particular embodiment, the compound of formula (I) obtained by means of the process provided by this invention is obtained in the form of a mixture of enantiomers, for example in the form of a racemic mixture. Therefore, if so desired, the obtained mixture of enantiomers can be resolved into its corresponding enantiomers to obtain the desired enantiomer. In a particular embodiment, said enantiomer is the (R) enantiomer [(+)-(R)-3-(2-hydroxy-5-methylphenyl)-N,N-diisopropyl-3-phenylpropylamine] or tolterodine, also known as pharmaceutically useful (R)-tolterodine. In another particular embodiment, said enantiomer is the (S) enantiomer [(−)-(S)-3-(2-hydroxy-5-methylphenyl)-N,N-diisopropyl-3-phenylpropyl-amine] or (S)-tolterodine, which also has therapeutic applications. The resolution of the mixture of enantiomers can be carried out by any conventional method, for example by using chiral chromatographic columns or by means of fractional crystallization of salts of the corresponding enantiomers with the appropriate chiral acids. In a particular embodiment, the separation of the (R) enantiomer from the compound of formula (I) is carried out by means of optical resolution treating the mixture of enantiomers with L-tartaric acid. The (R)-tolterodine salt L-tartrate or any other corresponding salt with a suitable chiral acid, can be recrystallized as many times required to obtain the (R) enantiomer of the compound of formula (I) with the desired purity. If so desired, the obtained enantiomer can also be converted into a pharmaceutically acceptable salt thereof by means of conventional processes known by those skilled in the art.
[0032] The starting material, compound of formula (II), can be prepared by oxidation of the corresponding alcohol of formula (IV)
wherein R is a hydroxyl protecting group and the asterisk indicates an asymmetric carbon atom.
[0034] Oxidation of the alcohol of formula (IV) to obtain the aldehyde of formula (II) can be carried out using any suitable oxidation agent, oxidizing system or method, capable of converting a primary alcohol into the corresponding aldehyde. However, in a particular embodiment, oxidation of the alcohol of formula (IV) into the aldehyde of formula (II) is carried out by using pyridinium chlorochromate (PCC), SO 3 .pyridine (SO 3 .pyr), the 2,2,6,6-tetramethylpiperidine (TMPP) N-oxide/NaClO system, or the Swern method, preferably the Swern method [Omura K. & Swern D. Tetrahedron 34:1651 (1978)]. The actuation means required for carrying out said oxidation, for example temperature, solvent, etc., shall be chosen according to the chosen oxidizing agent, system or method.
[0035] The alcohol of formula (IV) is a known product, the synthesis of which is disclosed, for example, in patent application WO 03/014060. Said alcohol of formula (IV) may alternatively be obtained by means of a process developed in this invention comprising reacting the compound of formula (V)
wherein R is a hydroxyl protecting group;
with ethylene oxide in the presence of a strong base, in a solvent.
[0037] Virtually any strong organic or inorganic base capable of withdrawing a proton from the methylene group present in the compound of formula (V) can be used; however in a particular embodiment, said base is an organic or inorganic base such as t-BuOK, BuLi, NaH, NaNH 2 , MeONa, etc. The reaction is carried out in a suitable solvent, for example dimethylsulfoxide (DMSO), dimethylformamide (DMF) or an ether, such as THF or dioxane, etc. This reaction is carried out at a temperature comprised between −80° C. and +50° C., preferably between −80° C. and −40° C. when the solvent is THF or DMF or between 20° C. and 60° C. when the solvent is DMSO. In a particular embodiment, the deprotonation of the compound of formula (V) is carried out with BuLi in THF, at a temperature comprised between −78° C. and −50° C. and the addition of the oxide ethylene is carried out watching that the temperature does not exceed —50° C.
[0038] The compound of formula (V) can be obtained from a compound of formula (VI) by means of a process comprising subjecting said compound to a Friedel-Crafts acylation reaction and subsequent deoxygenation (Alternative A) or to a Friedel-Crafts alkylation reaction (Alternative B). It is possible to prepare the compound of formula (V) by means of any of said alternatives, advantageously in which R is C 1 -C 4 alkyl or benzyl, from simple, accessible and cost-effective starting compounds and reagents, with short reaction times and high yields.
[0039] More specifically, obtaining the compound of formula (V) according to Alternative A comprises:
[0040] a) subjecting the compound of formula (VI)
[0041] wherein R is a hydroxyl protecting group;
to Friedel-Crafts acylation by reaction with a benzoyl halide in the presence of a Lewis acid to give the compound of formula (VII)
[0042] wherein R has the previously indicated meaning; and
[0043] b) subjecting said compound of formula (VII) to a deoxygenation reaction to give the compound of formula (V).
[0044] The benzoyl halide can be, for example, benzoyl chloride or benzoyl bromide. Virtually any Lewis acid can be used; however in a particular embodiment, said Lewis acid is tin tetrachloride (SnCl 4 ). Friedel-Crafts acylation is carried out in a suitable solvent, for example dichloromethane, acetonitrile, nitromethane, dioxane, DMF, etc. The addition of the Lewis acid is carried out at a temperature comprised between about 0° C. and 30° C., preferably close to 0° C.
[0045] Deoxygenation of the compound of formula (VII) can be carried out by conventional methods, for example by means of the use of a reducing agent suitable for the deoxygenation of ketones. In a particular embodiment, said reducing agent is selected from NaBH 4 in the presence of BF 3 .THF, NaBH 3 CN in the presence of BF 3 .THF, and Zn/HAcO. This reaction is carried out in a suitable solvent, such as an ether, for example, THF, dioxane, etc., a halogenated hydrocarbon, for example dichloromethane, etc., preferably THF.
[0046] The deoxygenation reaction can be carried out at a temperature comprised between 20° C. and 100° C., preferably between 50° C. and 70° C.
[0047] Obtaining the compound of formula (V) according to Alternative B comprises subjecting said compound of formula (VI) to a Friedel Crafts alkylation by reacting with a benzyl halide in the presence of a Lewis acid to give said compound of formula (V). The benzyl halide can be any suitable benzyl halide, for example benzyl bromide. Virtually any Lewis acid can be used; however in a particular embodiment, said Lewis acid is tin tetrachloride. Friedel-Crafts alkylation is carried out in a suitable solvent, for example acetonitrile, nitromethane, dioxano, DMF, etc. The addition of the Lewis acid is carried out at a temperature comprised between about 0° C. and 30° C., preferably close to 0° C.
[0048] In a particular embodiment, the preparation of the compound of formula (V) is carried out according to Alternative A. Although in comparison to Alternative B Alternative A comprises two reaction steps, it has the advantage that the reactions involved occur with high yields (see Example 1) around 78% and 93% respectively, which allows obtaining an intermediate ketone of formula (VII) in a simple manner and with a high yield. Said intermediate ketone can easily be purified by means of conventional recrystallization techniques, whereby a crystalline solid that can be used as a starting material purified in subsequent steps is obtained.
[0049] In another aspect the invention relates to the compound of formula (II). In a particular embodiment, the compound of formula (II) is a compound in which R is methyl. The compounds of formula (II) are new compounds, can be used in the synthesis of the compound of formula (I) and therefore constitute an additional aspect of this invention, as does their use in obtaining the compound of formula (I), particularly tolterodine.
[0050] In another aspect, the invention relates to a salt of a compound of formula (III), such as an addition salt with an acid. Virtually any organic or inorganic acid can be used to form said addition salt of the compound of formula (III). In a particular embodiment, said acid is an inorganic acid, e.g. hydrochloric acid, hydrobromic acid, sulfuric acid, etc. Non-limiting illustrative examples of said acid addition salts of the compound of formula (III) include hydrochloride, hydrobromide, sulfate, etc. Advantageously, said salt will be a salt that can be isolated from the reaction medium. Also advantageously, the anion of the salt of the compound of formula (III) is an anion of a pharmaceutically acceptable salt, for example, hydrobromide.
[0051] In a particular embodiment, said salt of the compound of formula (III) is N,N-diisopropyl-3-(2-methoxy-5-methylphenyl)-3-phenylpropyl-amine hydrobromide.
[0052] The salts de the compounds of formula (III) can be obtained by conventional methods by reacting the compound of formula (III) with the organic or inorganic acid at hand in a suitable solvent, such as an ester, an alcohol, etc. Optionally, if so desired said addition salt can be converted into the corresponding free amine [compound of formula (III)] by conventional methods, for example by changing the pH of a solution comprising said salt until the free amine is obtained.
[0053] The N,N-diisopropyl-3-(2-methoxy-5-methylphenyl)-3-phenylpropylamine hydrobromide salt can be obtained by reacting the compound N,N-diisopropyl-3-(2-methoxy-5-methylphenyl)-3-phenylpropylamine with hydrobromic acid and acetic acid in a suitable organic solvent, such as ethyl acetate, isopropanol, isobutanol, etc., and by maintaining the pH between 3 and 5, so that said salt precipitates, facilitating its isolation. Said salt constitutes a good starting material for obtaining the compound of formula (I), its enantiomers or mixtures thereof, or its pharmaceutically acceptable salts, for example, hydrobromide, by means of removal of the hydroxyl protecting group.
[0054] The salts of the compounds of formula (III) are new compounds, can be used in the synthesis of 3-(2-hydroxy-5-methylphenyl)-N,N-diisopropyl-3-phenylpropylamine, its enantiomers (R) and (S), or mixtures thereof, or its pharmaceutically acceptable salts, and therefore constitute an additional aspect of this invention as does their use in obtaining the compound of formula (I), particularly tolterodine. The process for obtaining said salt of the compound of formula (III) constitutes a further aspect of this invention.
[0055] The process provided by this invention allows obtaining the compound of formula (I), its isolated enantiomers or mixtures thereof, and its pharmaceutically acceptable salts, in particular the (R) and (S) enantiomers, from the compound of formula (II). Said compound of formula (II) can be obtained easily and with a good yield from the corresponding alcohol of formula (IV).
[0056] The process provided by this invention to obtain the compound of formula (I) has several advantages since it allows, among others, obtaining tolterodine without needing to go through reaction steps having, among other drawbacks, long reaction times; tolterodine can be prepared from simple, cost-effective and accessible starting compounds and reagents that are not expensive and/or hazardous, and it provides tolterodine and/or its pharmaceutically acceptable salts with a good yield and pharmaceutical quality. This all contributes to reducing the overall cost of the process of obtaining tolterodine, making said process commercially interesting and advantageously possible to be carried out to practice at an industrial level.
[0057] The following examples illustrate the invention and must not be considered as limiting of the scope thereof.
EXAMPLE 1
2-methoxy-5-methylbenzophenone
[0058] SnCl 4 (47.5 ml, 0.41 mol) was added dropwise to a mixture of 4-methylanisol (100 g, 0.82 mol) and benzoyl (95.15 ml, 0.82 mol) in 500 ml of CH 2 Cl 2 at 0° C. Once the addition is complete, it was allowed to react for 3-4 hours, allowing the mixture to reach room temperature. Once the reaction concluded, the mixture was cooled at 0° C., hydrolyzed with a mixture of concentrated HCl (41 ml) in H 2 O (376 ml), washed with 2×50 ml of NaOH (10%), dried and evaporated to give 140 g (78%) of the title compound in crystalline solid form.
EXAMPLE 2
(2-methoxy-5-methylphenyl)phenylmethane
[0059] BF 3 .THF (204 ml, 1.86 mol) and NaBH 4 (46.8 g, 1.24 mol) were added to a mixture of 2-methoxy-5-methylbenzophenone (140 g, 0.62 mol), in 840 ml of THF, and it was slowly heated to the reflux temperature (60° C.), maintaining it for about 6 hours. Once the reaction concluded, the mixture was cooled, added to 500 ml of NaHCO 3 (7%), and the organic phase was extracted with 200 ml of ethyl acetate, washed with 3×50 ml of NaHCO 3 (7%), dried and evaporated, giving a viscous liquid [122.5 g (93%)] containing the title compound.
EXAMPLE 3
3-(2-methoxy-5-methylphenyl)-3-phenylpropanol
[0060] BuLi (54.4 ml, 0.147 mol) was added to a solution of (2-methoxy-5-methylphenyl)phenylmethane (24 g, 0.113 mol), in 120 ml of THF at −78° C. Once the addition was complete, it was heated to room temperature and maintained at said temperature for about 2 hours. The temperature was again reduced to −78° C. and ethylene oxide (4.98 g, 0.113 mol) was added such that the temperature did not exceed −50° C. The reaction was allowed to take place, being complete after 2 hours. Then the mixture was hydrolyzed with 60 ml of NH 4 Cl, extracted with 30 ml of ethyl acetate, the organic phase washed with 2×25 ml of NH 4 Cl, dried and evaporated, giving 30 g (100%) of a viscous yellow liquid containing the title compound.
EXAMPLE 4
3-(2-methoxy-5-methylphenyl)-3-phenylpropanal
4.1 Oxidation Method (1)
[0061] Dimethylsulfoxide (DMSO) (6.72 ml, 94.6 mmol) in 20 ml of Cl 2 CH 2 was added to a mixture of oxalyl chloride (4.06 ml, 47.3 mmol) in 100 ml of Cl 2 CH 2 and cooled at −78° C., always maintaining the reaction temperature under −60° C. It was allowed to take place at said temperature for 15 minutes and then a mixture of 3-(2-methoxy-5-methylphenyl)-3-phenylpropanol (9.33 g, 36.4 mmol) in 40 ml of Cl 2 CH 2 was added. The reaction mixture was maintained for about 45 minutes and triethylamine (25.72 ml, 0.18 mol) was added. The crude reaction product was maintained reacting for about 1 hour and hydrolyzed with 100 ml of NaHCO 3 (7%). The extraction was carried out with 100 ml of ethyl acetate. The organic phase washed with 2×25 ml of HCl (5%), dried and evaporated, giving 8.67 g (94%) of a viscous orangish liquid containing the title compound.
4.2 Oxidation Method (2)
[0062] 3-(2-methoxy-5-methylphenyl)-3-phenylpropanol (0.5 g, 1.95 mmol) dissolved in 1 ml of Cl 2 CH 2 was added to a suspension of PCC (0.63 g, 2.93 mmol) and 0.5 g of MgSO 4 in 4 ml of Cl 2 CH 2 . The reaction was completed after 3 hours. Then it was filtered with celite and the filtrate was extracted with 2×25 ml of HCl (5%). The resulting organic phase was dried and the solvent was evaporated, giving 2.21 g of a dark viscous liquid containing the title compound.
4.3 Oxidation Method (3)
[0063] SO 3 .Py (1.56 g, 9.75 mmol) was slowly added to a mixture at 0° C. consisting of 3-(2-methoxy-5-methylphenyl)-3-phenylpropanol (0.5 g, 1.95 mmol), 6.5 ml of Cl 2 CH 2 , 0.54 ml of DMSO and triethylamine (2.7 ml, 19.5 mmol). Once the reaction concluded, it washed with a NH 4 Cl saturated solution (2×25 ml). The resulting organic phase was dried and the solvent was evaporated, giving 0.45 g of a black viscous liquid containing the title compound.
4.4 Oxidation Method (4)
[0064] Metachloroperbenzoic acid (0.04 g, 0.213 mmol) was added to a mixture consisting of 2.5 ml of Cl 2 CH 2 and 2,2,6,6-tetramethyl-piperidine (TMPP) N-oxide (3 mg, 0.022 mmol) at −10° C., and subsequently 3-(2-methoxy-5-methylphenyl)-3-phenylpropanol (0.5 g, 1.95 mmol) dissolved in 2.5 ml of Cl 2 CH 2 was added dropwise, maintaining the temperature at −10° C. Then the temperature was increased to 0° C. and a 10% NaOCl solution (1.3 ml, 2.13 mmol) at pH 9.5 was added dropwise, maintaining the reaction for 1 hour. Once this time elapsed, the reaction mixture was treated with water and Cl 2 CH 2 , giving 0.4 g of an impure, dense yellow liquid containing the compound of the title.
EXAMPLE 5
N,N-diisopropyl-3-(2-methoxy-5-methylphenyl)-3-phenylpropylanune
[0065] 3-(2-methoxy-5-methylphenyl)-3-phenylpropanal (8.67 g, 34.1 mmol) dissolved in 10 ml of THF, as well as diisopropylamine (5.78 ml, 40.92 mmol) were added to a suspension of NaHB(OAc) 3 (44.3 mmol) in 70 ml of THF, maintaining the crude reaction product for 2 hours. Once the reaction was concluded, it was hydrolyzed with 25 ml of NaHCO 3 (7%), extracted with 25 ml of ethyl acetate, washed with 2×25 ml of HCl (5%), the solvent dried and evaporated, giving 10.52 g (91%) of a viscous yellow liquid containing the title compound.
EXAMPLE 6
N,N-diisopropyl-3-(2-hydroxy-5-methylphenyl)-3-phenylpropylamine Hydrobromide
6.1 Method A
[0066] A suspension of N,N-diisopropyl-3-(2-methoxy-5-methylphenyl)-3-phenylpropylamine (10.52 g, 30.99 mmol) in 24 ml of HBr (48%) and 14 ml of acetic acid was heated under reflux (115° C.) for 72 hours. Then, 21 ml of ethyl acetate were added dropwise, it was stirred for 1 hour at 0° C. and filtered, giving 6.5 g (64%) of final product (title compound).
6.2 Method B
[0067] A suspension of N,N-diisopropyl-3-(2-methoxy-5-methylphenyl)-3-phenylpropylamine (0.85 g, 2.5 mmol) in 2 ml of HBr (48%), 1.1 ml of acetic acid and 4 mg of tetrabutylammonium bromide (phase transfer catalyst) was heated under reflux (115° C.) for 48 hours. Then, 2 ml of ethyl acetate were added dropwise, stirred for 1 hour at 0° C. and filtered, giving 0.8 g (80%) of final product (title compound).
EXAMPLE 7
R-(+)-N,N-diisopropyl-3-(2-hydroxy-5-methylphenyl)-3-phenylpropylaline Tartrate
[0068] 5.2 ml of NaOH (50%) were added to a suspension of N,N-diisopropyl-3-(2-hydroxy-5-methylphenyl)-3-phenyl-propylamine hydrobromide (53 g, 0.131 mol) in 750 ml of CH 2 Cl 2 and 375 ml of water, adjusting the pH to 9.5 with acetic acid if necessary. Once this pH was reached, it was maintained under stirring for 45 minutes and extracted with CH 2 Cl 2 , giving 42.55 g of the free amine. Then, a solution of 29.43 g of L-tartaric acid dissolved in 280 ml of ethanol at 60° C. was added to the amine dissolved in 140 ml of ethanol at 60° C. The reaction was maintained at a temperature comprised between 60° C. and 70° C. for 1 hour and cooled slowly to 0° C., maintaining it at said temperature for another hour. The resulting white precipitate was filtered and dried under vacuum for 14 hours, giving 31.08 g of the product.
[0069] Then, 1,200 ml of ethanol were mixed with the 31.08 g of product obtained and heated at 80° C. for 30 minutes; the ethanol volume was concentrated to half by distillation and was gradually cooled at room temperature and subsequently for 1 hour at 0° C. Tolterodine L-tartrate was obtained by filtration and it was dried under vacuum at 60° C. for 14 hours, giving 27.51 g of product. This process was repeated a second time with the 27.51 g of recrystallized tolterodine L-tartrate to give 22.23 g with a purity of 99.80% of the optically active compound.
EXAMPLE 8
N,N-diisopropyl-3-(2-methoxy-5-methylphenyl)-3-phenylpropylamine Hydrobromide
[0070] 3-(2-methoxy-5-methylphenyl)-3-phenylpropanal (8.67 g, 34.1 mmol) dissolved in 10 ml of THF, and diisopropylamine (5.78 mlj 40.92 mmol) were added to a suspension of NaB(AcO) 3 H (44.3 mmol) in 70 ml pf THF, maintaining the reaction for 2 hours. Once this time elapsed, 25 ml of NaHCO 3 (7%) were added, and the resulting product was extracted with 25 ml of ethyl acetate, washed with 2×25 ml of HCl (5%), the solvent was dried and evaporated, giving 10.52 g (91%) of a viscous yellow liquid.
[0071] A 33% BrH/CH 3 —COOH solution was added to the obtained residue redissolved in 40 ml of ethyl acetate and cooled at 10° C. until reaching a pH comprised between 3 and 5 (an aliquot is taken and mixed with water to measure the pH). During the course of the addition, a white solid precipitates which is left under stirring for 1 hour before filtering and washing with more ethyl acetate.
[0072] The obtained product is dried to give 7 g of the title product, free of impurities.
[0073] Melting point: 179.5-180.5° C.
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The process comprises reacting a compound of formula (II), where R is a hydroxyl protecting group, and the asterisk indicates an asymmetric carbon atom, with diisopropylamine in the presence of a reducing agent; optionally converting the resulting intermediate into a salt and, if so desired, isolating it; removing the hydroxyl protecting group; and if so desired, separating the desired (R) or (S) enantiomer, or the mixture of enantiomers and/or converting the obtained compound into a pharmaceutically acceptable salt thereof. Tolterodine is a muscarinic receptor antagonist useful in treating urinary incontinence and other symptoms of urinary bladder hyperactivity.
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[0001] This application claims priority of U.S. Provisional Patent Application Ser. No. 61/190,049, filed Jul. 16, 2008, the disclosure of which is herein incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] The use of electronics in pharmaceutical devices has become prevalent, especially in the management of assets, particularly those applications associated with inventory management. For example, the use of RFID tags permits the monitoring of the production line and the movement of assets or components through the supply chain. Additionally, these electronics allow more functionality to be embedded in the devices. Such functions as integrity testing, calibration and diagnostics, can now be performed in situ because of the use of these embedded electronics.
[0003] To further illustrate one such use of embedded electronics, a manufacturing entity may affix RFID tags to components as they enter the production facility. These components are then inserted into the production flow, forming sub-assemblies in combination with other components, and finally resulting in a finished product. The use of RFID tags allows the personnel within the manufacturing entity to track the movement of the specific component throughout the manufacturing process. It also allows the entity to be able to identify the specific components that comprise any particular assembly or finished product.
[0004] In addition, the use of RFID tags has also been advocated within the drug and pharmaceutical industries. In February 2004, the United States Federal and Drug Administration issued a report advocating the use of RFID tags to label and monitor drugs. This is an attempt to provide pedigree and to limit the infiltration of counterfeit prescription drugs into the market and to consumers.
[0005] Since their introduction, RFID tags have been used in many applications, such as to identify and provide information for process control in filter products. U.S. Patent RE 39,361, reissued to Den Dekker in 2006, discloses the use of “electronic labels” in conjunction with filtering apparatus and replaceable filter assemblies. Specifically, the patent discloses a filter having an electronic label that has a read/write memory and an associated filtering apparatus that has readout means responsive to the label. The electronic label is adapted to count and store the actual operating hours of the replaceable filter. The filtering apparatus is adapted to allow use or refusal of the filter, based on this real-time number. The patent also discloses that the electronic label can be used to store identification information about the replaceable filter.
[0006] U.S. Pat. No. 7,259,675, issued to Baker et al, in 2007, discloses a process equipment tracking system. This system includes the use of RFID tags in conjunction with process equipment. The RFID tag is described as capable of storing “at least one trackable event”. These trackable events are enumerated as cleaning dates, and batch process dates. The publication also discloses an RFID reader that is connectable to a PC or an internet, where a process equipment database exists. This database contains multiple trackable events and can supply information useful in determining “a service life of the process equipment based on the accumulated data”. The application includes the use of this type of system with a variety of process equipment, such as valves, pumps, filters, and ultraviolet lamps.
[0007] RFID tags are but one use of embedded electronics as used in pharmaceutical devices. U.S. Pat. No. 7,048,775 issued to Jornitz et al in 2006, discloses a device and method for monitoring the integrity of filtering installations. This publication describes the use of filters containing an onboard memory chip and communications device, in conjunction with a filter housing. The filter housing acts as a monitoring and integrity tester. That application also discloses a set of steps to be used to insure the integrity of the filtering elements used in multi-round housings. These steps include querying the memory element to verify the type of filter that is being used, its limit data, and its production release data.
[0008] Other patent applications have also disclosed the use of embedded sensors to aid in diagnostics or in situ integrity tests.
[0009] Despite the improvements that have occurred through the use of embedded electronics in pharmaceutical devices, there are additional areas that have not been satisfactorily addressed. For example, to date, embedded electronics and RFID tags cannot be employed in environments that require or utilize radiation. This is due to the fact that most electronic devices, and particularly memory storage devices, cannot withstand radiation. When subjected to radiation, specifically gamma and beta radiation, the contents of these memory elements are corrupted, thereby rendering them useless in this environment. Additionally, certain other electronic components, such as integrated circuits, fail when subjected to radiation. The most common failure mode is a condition commonly referred to as “latchup”. However, there are a number of applications, such as, but not limited to, the drug and pharmaceutical industries, where radiation of the system is a requirement. Furthermore, many electronic components cannot withstand temperature extremes, such as temperatures above 125° C. or below −55° C. These extreme temperatures are used in the pharmaceutical industry to sterilize materials, and to store finished product. Therefore, it would be extremely beneficial to these industries and others, to have embedded electronics that could withstand radiation and/or extreme temperature ranges without data loss or corruption.
SUMMARY OF THE INVENTION
[0010] The shortcomings of the prior art are overcome by the present invention, which describes a system and method for implementing embedded electronics in environments where radiation or extreme temperatures are used. Embedded electronics are affixed to various components of a pharmaceutical system, thereby enabling the customer to download pertinent information about the component, such as lot number, date of manufacturer, test parameters, etc. Additionally, these electronics allow an array of functions and features to be implemented, such as integrity tests, sensing of various parameters such as temperature, pH, conductivity, pressure and the like and diagnostics. The electronics in the pharmaceutical devices utilize a technology that is not as susceptible to radiation and extreme temperatures as traditional electronics.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows a cross-section of a traditional semiconductor substrate;
[0012] FIG. 2 shows the phenomenon that causes latchup in the substrates of FIG. 1 ;
[0013] FIG. 3 shows a cross-section of a Silicon on Insulator (SOI) substrate;
[0014] FIG. 4 shows a block diagram of a sensor;
[0015] FIG. 5 shows a cross-section of an ISFET;
[0016] FIG. 6 a shows one orientation of a bag and attached semiconductor;
[0017] FIG. 6 b shows a second orientation of a bag and attached semiconductor; and
[0018] FIG. 7 shows a heater used with a SOI substrate in accordance with one embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The use of miniature and embedded electronics has become more and more prevalent. However, in certain applications, their use is limited, or not possible. For example, any environment in which the electronics must be subjected to radiation will corrupt or destroy the physical device, or may alter the state of the device. Therefore, devices that are gamma or beta irradiated, such as pharmaceutical components, or subject to x-rays, such as devices that pass through airport security systems, currently cannot easily utilize electronic circuits. Thus, products used in these environments must find alternative solutions. For example, in some cases, the electronics are eliminated and a simple barcode is affixed to the device, and a database is used to store and retrieve the pertinent information associated with that barcode. In other words, the memory element of the tag is literally removed and kept elsewhere. While this allows the data associated with the device to be saved and retrieved, it requires computer access and a remote database for storage. This solution is further complicated when the device manufacturer and the device user both want to access and update the associated information. Such an arrangement requires joint access to the database, which may be difficult or impossible due to the need for confidentiality and data protection.
[0020] A second solution involves affixing the embedded electronics at a point in the process after the irradiation of the device. For example, pharmaceutical components are often subjected to gamma or beta radiation. Application of the electronic devices after this step can bypass the memory corruption and circuit malfunction issues described above. However, data associated with that component which was created before the radiation step must be somehow saved and associated with the appropriate component, so that the later affixed electronics contains all of the required information. Additionally, the electronic device must itself undergo some sterilization process before it can be affixed to the pharmaceutical device.
[0021] A third solution is to prohibit the use of radiation with the device. Thus, users must find an alternate approach to achieve the results sought by irradiating the device (such as high temperature steam sterilization). However, sterilization, such as by autoclave, requires temperatures typically in excess of 145° C. Military grade integrated circuits, which are more costly than standard commercial grade equivalents, are typically only rated to 125° C. Thus, steam sterilization also potentially can damage the electronics. Obviously, none of these solutions is optimal.
[0022] At the root of the problem is the inability for a traditional semiconductor device to withstand sterilization, such as by gamma or beta radiation or steam sterilization. This is a very well known problem, and affects all types of CMOS semiconductor devices, including transistors, memory circuits, amplifiers, power conversion circuits, and analog/digital and digital/analog converters. FIG. 1 shows the typical structure for a CMOS device. The N channel MOSFET 100 comprises a N-type source 101 separated from an N-type drain 102 . The gate 103 is located between these two N-type regions. The substrate 104 around the MOSFET is p-type. The P channel MOSFET 110 comprises a P-type source 111 separated from a P-type drain 112 . The gate 113 is located between these two P-type regions. The substrate around the MOSFET is n-type moat or well 114 . When exposed to radiation, these CMOS devices typically fail in such a way that both the NMOS transistor 100 and its complementary PMOS transistor 110 both turn on, effectively creating a SCR 200 (silicone controlled rectifier) or thyristor. These devices are essentially N—P—N—P devices, which, once turned on, can only be turned off by the removal of power from the device. Typically, the SCR is created between the p-drain 112 , n-moat 114 , p-substrate 104 and n-drain 102 of the adjacent transistor, as shown in FIG. 2 . Thus, the activation of this SCR creating a short circuit between the power rails of the CMOS device, which persists until the power is removed from the device. Although this problem most often occurs between power rails, other short circuits within the device are also possible. Failure to mitigate this failure can lead to permanent damage.
[0023] Other semiconductor fabrication techniques are known to exist. One such technique is known as Silicon-on-Insulator (or SOI). SOI fabrication has been in use for about 10 years. Companies, such as Honeywell and Cissoid, have commercialized circuit components necessary to assemble wireless communication devices as well as basic sensor circuits and amplifiers. Typically, integrated circuits made using SOI techniques are resistant to junction temperatures up to 225° C., well in excess of current military standards available for traditional CMOS devices. For example, traditional integrated circuits are typically specified for two maximum temperatures; operational and storage. Most standard integrated circuits have a maximum storage temperature of 150° C., and a maximum operating temperature of 125° C. In contrast, SOI based integrated circuits are commonly rated at 225° C. operating temperature.
[0024] In contrast to traditional semiconductors, insulating material 300 , such as silicon dioxide (SiO 2 ), aluminum oxide (Al 2 O 3 ) or other suitable materials, separates the various transistors from one another and from the bulk substrate 330 . FIG. 3 shows a cross-section of a typical SOI device. Note that the presence of the insulating material 300 between the transistors 310 , 320 prohibits the formation of the SCR device described above, thereby mitigating the possibility of latch-up in these devices. In addition, the insulating material isolates the transistors 310 , 320 from the doped substrate 330 .
[0025] As stated above, pharmaceutical devices need to be sterilized. The most common forms of sterilization include gamma or beta radiation, and high temperature steam sterilization, both of which are impossible with traditional semiconductor devices.
[0026] Currently, the pharmaceutical industry is pursuing the use of disposable components. Typically, these parts are manufactured by the pharmaceutical company and then shipped to the customer. Often, the customer assembles these disposable components into a complete system, which they may then sterilize before use. Such disposable systems include the Mobius® line of products manufactured by Millipore Corporation.
[0027] Many of these disposable products benefit because of the advantages listed above. For example, through the addition of embedded electronics. For example, RFID tags can be read and rewritten by the manufacturer and/or customer to allow improved inventory processes. Based on this, it is possible to develop a sophisticated pharmaceutical asset management system. In one embodiment, the pharmaceutical components, such as filtration devices, hoses and the like, have a remotely readable tag affixed to them, such as an RFID tag. This tag contains device specific information, such as, but not limited to device specific information (such as serial number, date of manufacture, etc.), device specifications (such as upper and lower pressure limits), and device test parameters. Customers could use this information in a variety of ways. For example, an automated instrument setup and calibration procedure can be established. By using an RFID or equivalent reader, the customer could determine calibration values, upper and lower limits, units of measure and/or the data exchange protocol.
[0028] This semiconductor technique can also be used to create other embedded electronic components that can withstand sterilization, such as pressure, temperature and concentration sensors. It is desirable to use sensors to measure fluid conditions, such as temperature, pressure and flow rate. It is also desirable to measure fluid components, such as by using a chemical or concentration sensor. The use of some of these types of sensors is described in U.S. patent application Ser. Nos. 11/402,737, 11/402,437, and 11/402,438, the disclosure of each is hereby incorporated by reference. In these cases, information obtained by the sensors can be stored in embedded memory and read by the customer at a later time. Alternatively, the sensor data can be transmitted wirelessly to a remote transmitter or receiver.
[0029] Sensors 400 are typically made up of a number of subcomponents, as shown in FIG. 4 . There is a sensor head 410 , which is the portion of the sensor that converts the physical characteristic, such as pressure or temperature, to an electrical signal. This signal can be a voltage, a current, a resistance, or any other electrical quantity. The sensor body is typically made up of a number of subcomponents, such as a signal processing unit 420 , an analog to digital converter 430 , a transmitter 440 and a power circuit 450 .
[0030] The output from the sensor head may be passed to a signal processing unit 420 . This unit 420 may perform a number of different functions. For example, this unit 420 may scale the incoming signal to change the input range into a different output range. For example, an incoming signal may be in the range of 0-100 mV, whereas the desired output is between 100 mV and 1V. The signal processing unit 420 would translate and scale the incoming voltage to achieve the desired output range.
[0031] Alternatively, the signal processing unit 420 may add compensation for thermal drift or other variables. For example, a pressure sensor may experience an offset based on the ambient temperature. The signal processing unit 420 can compensate for such an error.
[0032] In addition, the signal processing unit 420 may adjust the received signal based on known process variation. For example, devices may vary for each production lot. This variation may be determined by a tester, which then records the required compensation value in the signal processing unit 420 . This value may be added to the output, or may be a scaling factor.
[0033] Additionally, the signal processing unit 420 may include means for calibration. In this case, the signal processing unit 420 may include means to test the process variation and thermal drift. It then performs a calibration test to determine these factors and uses them to appropriately adjust the received electrical signal.
[0034] A third subcomponent of a sensor may be an analog to digital converter 430 . Typically, the sensor head 410 produces an analog output, as a voltage, current or resistance. This output may need to be converted to a digital value. This is typically accomplished through the use of an analog to digital converter 430 . This analog to digital converter 430 may receive the output of the signal processing unit 420 . Alternatively, it may receive the output of the sensor head 410 and supply a digital value to the signal processing unit 420 . In a third embodiment, the analog to digital converter 430 is located within the signal processing unit 420 and converts the signal after unit has been partially processing by the signal processing unit 420 .
[0035] A fourth subcomponent is a transmitter 440 . In some embodiments, the transmitter 440 is simply a wire, which connects the sensor components to an external reader. In other embodiments, the transmitter 440 may be wireless. A wireless transmitter may utilize any protocol, and the disclosure is not limited to any particular embodiment. For example, protocols such as Zigbee, 802.15.1, 802.15.4, RFID, Bluetooth® and others, are suitable for this application.
[0036] A fifth subcomponent of a sensor 400 is the power circuit 450 . This circuit 450 provides the required power to the rest of the sensor 400 . In some embodiments, a battery is used as the energy source. In other embodiments, wireless induction is used to supply energy to the sensor. In addition to supplying energy, the power circuit 450 transforms that energy into the required voltages, typically through the use of rectifiers, zener diodes, capacitors, and other components.
[0037] In some embodiments, as is described in more detail below, the above described sensor 400 is at least partially made using SOI technology. For example, in some embodiments, the entire sensor is made using SOI technology. In other embodiments, only certain subcomponents are made using SOI technology.
[0038] For example, in some embodiments, the signal processing unit 420 , which may include integrated circuits, is made using SOI technology.
[0039] In other embodiments, the sensor head 420 is made using SOI technology. For example, ISFETs can be used in the creation of concentration sensors. These ISFETs utilize drain and source regions analogous to those found in a MOSFET. FIG. 5 shows an ISFET 500 made using SOI technology. Like traditional MOSFETS, the ISFET has an n-type drain region 510 and an n-type source region 520 . Both regions are located within a p-type substrate 530 , such as silicon. An insulator 540 is then layered on top of the p-type silicon 530 , the source 520 and the drain 510 , leaving only a small area on the source and drain regions for connection to the metal contacts 550 . The metal gate traditionally used for a MOSFET is replaced by an electrode 560 spaced apart from the device. The ions in the solution 570 provide the electrical path from the electrode 560 to the device. Thus, the concentration of electrons determines the strength of that electrical path, and therefore the amount that the FET is enabled.
[0040] Other examples of a sensor head using SOI technology are the use of LEDs or photodiodes. These LEDs can be used to detect concentration density when used with fluorescent materials, and can also be made using SOI technology.
[0041] Additionally, SOI technology is suitable for other devices, including amplifiers, analog-to-digital converters, digital-to-analog converters, digital logic, radio frequency components, power conversion circuitry and memory devices.
[0042] Finally, the ability to utilize a remotely readable asset management tag is beneficial for pharmaceutical consumables, such as filters, bags, tubes and process instruments. Currently, the pharmaceutical industry is exploring the use of disposable technology. In this scenario, the customer could configure their required system using at least some disposable components (such as filters, bags, hoses, etc). This allows the customer to customize their configuration as necessary and also eliminates the costly cleaning operations that must currently be performed. To improve the efficiency and predictability of using disposable components, RFID tags can be affixed to these components. Such tags allow for the wireless automated identification of components, including such information as catalog number, serial number, and date of manufacture. These tags also allow a secure automated method of transferring unit specific specification to the customer as noted above. Using the information contained within these tags, a GAMP compliant method of transferring unit specific test procedure information to an automated integrity tester can be created. The semiconductor devices described above are beneficial in this application, since these disposable components must be irradiated to insure sterilization. Furthermore, in addition to storage and wireless communications that can be provided by RFID tags, other functions are also possible given the use of SOI technology.
[0043] There are various applications where this SOI technology would be beneficially employed. Currently, there are some disposable pharmaceutical components that employ sensors. Due to the issues associated with sterilization described above, many separate the sensor into two connectable portions; a sensor head and a sensor body, which contains the remaining subcomponents. The sensor head contains a minimal amount of complexity and is typically designed in such a way so as to be able to withstand radiation or high temperature. The sensor body includes the electronics required to control the inputs to the sensor field and to convert the output from the sensor head into a meaningful result. These two components are typically connected via leads, such as wires, and are connected after the sterilization process is completed.
[0044] The use of SOI technology allows for much improved and more convenient implementation of electronics in sterilized pharmaceutical components. For example, in some embodiments, the sensor head is very sensitive and requires individualized calibration to insure proper readings. For example, an analog output from a sensor head may be related to the temperature by a particular equation, wherein the coefficients of that equation are unique to the sensor head. By calibrating the sensor head and storing those values proximate to the sensor head, the sensor head can now be used with a generic sensor body without any additional calibration required. Storing these calibration values proximate to the sensor head requires that the storage device be capable of withstanding some type of sterilization process. Memories manufactured using the SOI technologies can be integrated into the sensor head, allowing calibrated sensors to be employed.
[0045] In a second embodiment, the sensor head and sensor body are incorporated into a single self-contained component. This self-contained sensor includes the previously described sensor head. As described above, it also includes a power conversion/generation circuit, which generates power for the device, preferably from radiated electromagnetic fields. The sensor also includes the circuitry necessary to convert the analog output from the sensor head into a digital value, the logic required to convert that value to an appropriate computer usable result, and a transmitter to deliver that result, preferably wirelessly to an external device. If all of these components are manufactured using SOI, the entire sensor can be sterilized without fear of damage or degradation.
[0046] As mentioned above, electronic devices using SOI technology can withstand gamma or beta radiation. To increase the amount of radiation that the electronic device can withstand, it may be possible to change the orientation of the device during the sterilization process. Typically, gamma rays are directed predominantly along one axis. For example, assume that the gamma rays are moving in the Z axis. Typically, the item to be sterilized, such as a pharmaceutical bag, is placed such that its maximum surface area is positioned perpendicular to the flow of gamma rays. FIG. 6 a shows gamma rays 600 flowing in the Z axis. The item to be sterilized 610 and the attached semiconductor device 620 are positioned so as to maximize the surface area impacted by the gamma rays 600 . While this orientation is best for the item to be sterilized 610 , it subjects the semiconductor device 620 to high levels of radiation.
[0047] To reduce these levels of radiation, the semiconductor device 620 can be oriented such that its cross-section (as viewed in FIG. 3 ) is perpendicular to the flow of gamma rays (such as in the XY plane). Stated another way, the maximum surface area of the semiconductor device 620 is oriented so as to be coplanar to the direction of the gamma rays, as shown in FIG. 6 b. In this way, a minimal surface area is susceptible to being impacted by the rays. Other orientations are also possible, where the cross-sectional exposure of the electronic device is not at its maximum. However, the item to be sterilized 610 still exposes a large cross-section to the gamma rays 600 .
[0048] Other techniques may also be used to reduce the effect of gamma or beta radiation on these electronic devices. In some embodiments, a SOI device may be temporarily disabled or affected by the exposure to radiation. Reconditioning, by applying heat or simply allowing time to elapse, may be an effective method to restore the functionality of the device. In one embodiment, after the device is sterilized, it is not used for a predetermined period of time to allow it to recondition itself. In a second embodiment, after the electronic device is sterilized, it is subjected to heat to recondition it. In a further embodiment, a small heater may be installed near the semiconductor device that can be activated after exposure to radiation. FIG. 7 shows an example of such a heater 710 . For example, the heater 710 may consist of a small coil oriented around the semiconductor device 700 . The coil can receive induced electromagnetic waves, which it then converts to current. This current is used to create heat, which is used to recondition the semiconductor device 700 . After exposure to radiation, this heater 710 can be activated, which supplies localized heat to the semiconductor device 700 , allowing it to recondition itself.
[0049] In addition to the benefit of withstanding sterilization, these semiconductor devices can also operate at high temperature ranges. Therefore, it is also possible to have these sensors functional during a high temperature steam sterilization procedure. Thus, in situ temperature measurements can be made during sterilization or autoclaving, which allows the operator to verify that the sterilization temperature ranges and profiles conform to required values. In contrast, the actual temperature profile of a hot steam sterilization cycle currently cannot be monitored in situ.
[0050] In addition to withstanding high temperatures, it is also believed that SOI technology is more tolerant of extremely low temperatures, such as much less than −55° C. The ability of a semiconductor material to conduct is proportional to the dopant level and the base energy level, or thermal state. Typically semiconductor devices are doped to operate within the common industrial temperatures, −55 to +85 C. Increasing the temperature of the semiconductor device will increase the ability for the device to conduct or change states. However, at lower temperatures, the energy required to excite the transistor may exceed the maximum input energy and therefore standard devices will not operate reliably below −55° C. SOI can more reliably operate at lower temperatures than standard semiconductor devices because less input energy is lost to parasitic leakage to adjacent devices.
[0051] This feature can also be advantageous exploited by pharmaceutical components. For example, many pharmaceutical products are stored in sub-freezing environments. Furthermore, the temperature profile of the drug as it is being frozen is critical to maintaining the proper molecular and crystalline structure. A temperature sensor that is able to operate at these frigid temperatures would allow the operator to monitor the temperature as the product is being frozen to verify that the proper temperature profile was followed.
[0052] In one embodiment, the temperature sensor records the temperature at fixed intervals and stores these values in an internal memory. At a later time, these stored values can be retrieved by an external device that compares the stored values to acceptable temperature profiles. In another embodiment, the temperature sensor transmits these values to an external device, which monitors the temperature of the product as it is being frozen. The transmission can be by wire or wirelessly as described above. The external device can then insure that a proper temperature profile was followed.
[0053] This procedure is not possible today. Rather, freezers are calibrated and then products frozen in that freezer unit are assumed to have followed the profile exhibited during calibration. Therefore, this new approach would allow the operator to insure that each product was subjected to a proper freezing profile, since the temperature versus time data would be attainable for each individual product.
[0054] Similarly, this technique can be used to monitor and verify the thawing process. As the frozen product is thawed, its temperature can be recorded by the temperature sensor, as described above. The thawing continues until the product reaches its desired use temperature. The collected temperature values can then be compared to a proper or acceptable temperature profile to insure the quality of the product.
[0055] This technique can also be used to calibrate the freezing profile of the freezer itself. For example, a freezer is calibrated using thermocouple wires that are thread into the interior. Due to the freezers design with insulation and sealed enclosure, routing the thermocouples to the preferred locations within the interior can be complicated and time consuming. A device that can wireless communicate through the closure or portals of the freezer may be used to allow temperature to be measured with the enclosure.
[0056] Silicon on Insulator (SOI) technology is also believed to be more resistant to magnetic fields, especially alternating magnetic fields. This is believed to be true for several reasons. First, SOI transistors can hold their state more effectively and efficiently to reduce the effects of induced currents from the AC field. Second, SOI transistors have less leakage, therefore they will be less susceptible to draining the transistors in an excited state. Such an environment may be encountered in various applications, For example, in the pharmaceutical industry, magnetically levitated mixer heads are often used, such as in the Mobius® Mix 100, 200 and 500 disposable mixer systems available from Millipore Corporation of Billerica, Mass. These systems use a magnetic drive on the outside of the mixing container to remotely drive a magnetic impeller within the container in order to mix its contents either as a straight industrial mixer or as a bioreactor. The use of SOI technology will allow electronics to be placed in closer proximity to this magnetic field source.
[0057] Perhaps the most interesting application of this technology is in disposable products for the biopharmaceutical or medical industry where one or more of these conditions are used on the same product over its life time. Having electronics that are capable of working in any or all of these conditions would be exceedingly useful to the operator. For example, a sample bag used on a disposable bioreactor, can have one or more electronic devices, for example a RFID or other wireless communication and memory storage device. One such system is taught by copending application WO 2009/017612. Having electronics of the SOI type, one can form the sampler bag and attach a wireless communications and memory device and then gamma or beta sterilize it for shipping, storage and use by the customer. Data relating to the lot number, date of manufacture, use restrictions and the like can be safely added before gamma or beta sterilization and read after gamma or beta sterilization. One or more trackable events such as the date of use, the location of use, operator, sample taken etc can be added to the memory by the user as a paperless record keeping system and may interface with its Good Manufacturing or Good Laboratory practices systems such as a LIMS systems. The sample may then be frozen as a retain and the SOI based electronics will allow it to be safely stored at those temperatures and thawed at a later date with its memory and stored data intact.
[0058] Similar applications apply to the medical field where blood or other components can be added to gamma or beta sterilized containers and stored at low temperatures until needed. Likewise, retains or medical samples such as biopsies could be handled in the same manner and yield the same satisfactory results.
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A system and method for implementing embedded electronics in environments where radiation or extreme temperatures are used is disclosed. Embedded electronics are affixed to various components of a pharmaceutical system, thereby enabling the customer to download pertinent information about the component, such as lot number, date of manufacturer, test parameters, etc. Additionally, these electronics allow an array of functions and features to be implemented, such as integrity tests and diagnostics. The electronics in the pharmaceutical components utilize a technology that is not as susceptible to radiation and extreme temperatures as traditional electronics.
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TECHNICAL FIELD
The present invention relates generally to wallcovering and is more particularly concerned with a new and improved nonwoven fibrous backing material for vinyl wallcovering and the like.
BACKGROUND OF THE INVENTION
Originally, wallcovering was simply paper printed with a design and suited for being pasted to a wall or other surface for decorative purposes. In the 1920's vinyl wallcover was introduced and had a backing of woven fabric or scrim that not only facilitated hanging of the paper, but also provided strippability characteristics not previously provided by the printed papers. Unfortunately, the fabric backed vinyl wallcover was substantially more expensive than the simple printed paper and exhibited physical disadvantages relating to permeability and adhesion. Subsequently, wallcover manufacturers began to use paper and then nonwoven material as a backing for their vinyl wallcover products. Although the paper backings are somewhat less expensive than the nonwoven backings, they are not as pleasing aesthetically, are physically less durable, and are far more difficult to process into the desired end product. The nonwoven material, on the other hand, is less expensive than the woven backing while at the same providing superior strength, toughness, softness, and embossability retention relative to the paper backing material.
The nonwoven material used as vinyl wallcover backing is typified by the inclusion of stronger, tougher synthetic fiber that may be present in amounts from approximately 5 percent to more than 50 percent of the total fiber content of the material. The synthetic fibers use heretofore typically have been polyester fibers and constitute about 50 percent of the total fiber content of the backing material. This is particularly important for vinyl wallcovers since such fibers assured hangability without stretch or deformation.
Vinyl wallcover is produced by providing a layer of vinyl on the nonwoven backing. Theoretically this can be accomplished by one of two distinctly different techniques--coating with a plastisol or laminating with a vinyl film. The plastisol coating technique uses a reverse roll, rotary screen, doctor blade or similar technique. In the former instance, the procedure has the disadvantage of a severe hydraulic shear action on the surface of the backing material since the applicator roll is turning at approximately three times the speed of the backing carrier roll and is moving in a reverse roll direction. This causes substantial pilling on the surface of the nonwoven backing, particularly on those nonwoven backing materials that utilize a high polyester fiber content since the ends of the synthetic fibers are exposed to the shearing action of the procedure. The pilled surface of the backing tends to show through the vinyl plastisol layer and provides an aesthetically displeasing result. The synthetic fiber ends of the nonwoven material tend to cause dimpling when the vinyl plastisol coating is applied. Bleed through of the plastisol with its resultant uneven coating that adversely affects the printing of the design on the vinyl surface has also been problem. Because of these difficulties the coating process is seldom employed with nonwoven backing on a commercial basis.
Where the vinyl layer or surface is applied by laminating a preformed vinyl film onto a substrate or backing, it has been necessary to utilize an adhesive plus a heated calender roll to drive off the solvent. That technique not only requires the preparation of the adhesive with its attendant cost but also involves high energy usage associated with removing water or other solvent from the adhesive layer. Further, the volatility of the adhesive solvents used in laminating the preextruded film to the backing tends to result in an undesirable environmental condition.
SUMMARY OF THE INVENTION
According to the present invention, it has been found that a unitary but multiphase nonwoven fibrous backing will enable wallpaper manufacturers to make a functionally improved product at lower cost than has been possible with wallcover backing presently on the market. This unitary multiphase or multistratum fibrous web material not only provides coatability without pilling, but also imparts superior aesthetic qualities to the resultant wallcovering. A coated wallcover now becomes a commercial reality and even eliminates the need for the more expensive preextruded vinyl film. The wallcover backing of the present invention also can be used with vinyl film while advantageously eliminating many of the problems associated therewith, including the energy usage required to cure the adhesive and remove any solvent therefrom. The wallcover backing of the present invention not only provides a physically superior backing material as compared with paper but also provides improved processability, strippability, and cost savings coupled with the desirable toughness, softness, and embossability retention associated with nonwoven wallpaper backing materials.
The new and improved wallcover backing of the present invention provides a multiphase structure with the top phase free from synthetic polyester fibers. Additionally, the top phase of the multiphase material provides a smooth coating surface completely free from polyester fiber ends thereby eliminating the pilling problems previously associated with the coating process. This wallpaper backing material permits customizing and variability in the desired product while eliminating the need for an additional adhesive where the backing is use with a preformed vinyl film. Finally, improved hangability and dimensional stability of the product is coupled with uniform, controlled, and very limited plastisol migration and adhesive penetration so as to provide uniform performance both from a strippability and coatability viewpoint.
These and related advantages are obtained in accordance with the present invention by providing a vinyl wallcover backing for strippable vinyl wallcovering comprising a dimensionally stable unitary multistratum nonwoven fibrous web material. This material has a fibrous top stratum adapted for secure nondelaminating engagement with a vinyl layer superimposed thereon, and a fibrous base stratum integrated with the top stratum and adapted for strippable adhering engagement with a wall or the like. The top stratum constitutes at least 5 percent by weight of the multistratum web and has a smooth exposed surface for direct adhesion to the vinyl layer. The multistratum web includes about 15 to 45 percent by weight of a latex binder and contains an adhesive penetration inhibitor adapted to inhibit the migration of a wallcover adhesive into the fibrous web material and to promote uniform and full strippability of the web from the wall to which is applied.
A better understanding of this invention will be obtained from the following description of the wallcover backing, and the process for its manufacture including the several steps of that process and the relation of one or more of such steps with respect to each of the others and the article of manufacture possessing the features, characteristics, compositions, properties, and relation of elements described and exemplified herein.
DETAILED DESCRIPTION
The multistratum wallcover backing of the present invention generally may include substantially the same bottom phase or stratum regardless of the process to be employed in applying the vinyl layer thereto. However, the top phase of the multistratum nonwoven web material typically will vary depending upon the particular process used to apply the vinyl layer. For example, where the vinyl layer is to be applied as a liquid plastisol via a coating technique using a reverse roll rotary screen or knife coating process, the top phase consists primarily of synthetic wood pulp, natural cellulosic fibers or a mixture thereof with the synthetic wood pulp at least partially fused to present an extremely smooth surface to the plastisol coating operation. On the other hand, where a preformed vinyl film is to be applied as the vinyl layer, it is preferred that the top stratum contain thermoplastic heat sealable fibers that exhibit a high affinity for the vinyl film. In this way, the heat sealable fibers firmly and securely bond the preformed vinyl layer to the backing without the need for additional adhesives and without the need to expend the energy necessary to drive off solvents, such as water vapor, from the adhesive utilized to adhere the vinyl film to the backing material.
In carrying out the present invention the multiphase material preferably is produced in the form of a continuous water-laid nonwoven web material using known and conventional papermaking techniques. The wet papermaking process involves the general steps of forming separate fluid dispersions of the requisite fibers for each phase and sequentially depositing the dispersed fibers on a fiber collecting wire in the form of a continuous sheet-like web material. The fiber dispersions may be formed in a conventional manner using water as a dispersant or by employing other suitable fiber dispersing media. Preferably, aqueous dispersions are employed in accordance with known papermaking techniques. The fiber dispersion is formed as a dilute aqueous suspension of papermaking fibers, i.e., a fiber furnish. The fiber furnish is conveyed to the web forming screen or wire, such as a Fourdrinier wire, of a papermaking machine and the fibers are deposited on the wire to form a fibrous web or sheet that is subsequently dried in a conventional manner. The web material thus formed is treated either before, during or after the complete drying operation with a latex treating solution used in accordance with the present invention, but in the preferred embodiment is treated subsequent to the drying operation.
As mentioned, the invention is primarily concerned with multiphase sheet material since such material will provide effective coverage of the synthetic polyester fibers. In such material not only is the top surface substantially free of such fibers but it is quite smooth and receptive to the vinyl layer that is to be placed thereon and secured thereto. In this connection, numerous different techniques have been employed heretofore to make a multiphase fibrous web. Typical of those found most useful in the production of web materials utilized in accordance with the present invention is the multiple headbox inclined wire technique described in U.S. Pat. No. 2,414,833. In accordance with that process, a first furnish of non-heat seal fibers flows through a primary headbox and continuously deposits as a first or bottom phase on an inclined fiber collecting screen. A second furnish containing fibers for the top phase is introduced into the headbox at a location close to but slightly downstream of the point of deposition of the fibers from the first furnish. The introduction of the second furnish may be carried out by means of an inclined trough, by a secondary headbox or by other means in such a manner that the fibers from the second fiber furnish comingle slightly with the fibers forming the bottom phase but only after a portion of those fibers have been deposited on the inclined wire. In this way, the fibers within the bottom phase have a chance to provide a base prior to the deposition of the fibers forming the top phase. As is appreciated, the latter is secured to the base phase through an interface zone formed by the intermingling of the fibers from the respective furnishes. Typically, sheets produced in this manner will have fibers from only the first furnish covering the entire surface of the sheet on the surface in contact with the inclined fiber collecting screen, while the fibers of the top phase completely cover the bottom phase or stratum so as to mask the presence of the synthetic fibers therein yet at the same time utilize the strength and toughness characteristics imparted to the sheet material thereby. Additionally, in this way there is no clear line of demarcation between the two phases of the multiphase sheet material. However there is a predominence of secondary furnish fibers on the top surface of the multiphase sheet. The interface or boundary between adjacent phases, of course, is composed of a mixture of the fibers within both fiber furnishes.
The multiphase fibrous web material thus formed is typically dried in a conventional manner by passing it over drying drums heated to temperatures of about 220° F. and higher or by other conventional drying techniques. Thereafter, the multiphase fibrous web material is treated with a suitable binder, preferably a hydrophobic material, and with a penetration inhibitor to inhibit the penetration of the wallcover adhesive as well as the penetration of the plastisol when the vinyl layer is formed by a coating technique.
The bottom phase of the multiphase nonwoven web material is composed of a mixture of natural and synthetic fibers with the synthetic fibers being of the type that are thermally stable up to about 165° C. The natural cellulosic fibers used in the fiber furnish for the base phase provide not only a less expensive fiber content, but also provide a smoother surface finish to the exterior bottom surface of the multiphase nonwoven web material. The synthetic fibers, on the other hand, impart to the web material greater tear strength, higher tensile, greater toughness and elongation and better fabric like appearance and feel. Accordingly, the proportions of the synthetic fiber to natural cellulosic fiber will vary extensively, with the synthetic fiber content varying from as little as 1 to 2 percent up to about 95 to 98 percent of the total fiber furnish. Generally however, it is preferred that the synthetic fiber content of the base phase fall within the range of about 5 percent to 60 percent by weight. The amount of synthetic fiber within the base phase categorizes the entire sheet material as either a high synthetic nonwoven material or a low synthetic material. For example, if the base phase contains 50 percent or more of synthetic fiber, it is categorized as a high synthetic grade material whereas if the synthetic fiber content of the base phase is about 15 to 35 percent, the entire web material is categorized as a low synthetic type material. The amount of synthetic fiber used in the base layer, or base phase will vary somewhat, depending upon the affinity of the fibers for the subsequent treating materials as well as the particular properties desired in the resultant product.
Accordingly, a wide variety of natural and synthetic fibers may be used in the base phase. The synthetic or man-made fibers may include cellulosics such as rayon, nylons such as polyhexamethylene adipamide and aramid, acrylics such as polyacrylonitriles, high melting polyolefins such as polyethylene and polypropylene, and vinyl polymers and copolymers. However, the preferred synthetic fiber is polyester fiber such as polyethylene terephthalate in view of its cost and the characteristics it imparts to the base web material when utilized for wallcover backings; that is, dimensional stability, hangability and similar physical properties. Natural cellulosic fibers, such as bleached and unbleached Kraft, hemp, jute and similar conventional papermaking fibers may be employed. For particular applications other fibers such as glass, quartz, mineral wool and the like may be used.
The top phase of the multiphase nonwoven fibrous web material provides not only a covering of all the synthetic fibers within the base phase and the elimination of the exposure of any free ends of the synthetic fibers, but also provides a smooth surface on which to apply and affix the vinyl layer. The top phase will vary depending upon the nature of the vinyl layer being applied. For example, when using a coating technique with a vinyl plastisol, it is generally preferred that the top phase provide a tight, dense covering of the synthetic fibers, so that the plastisol readily sits on the surface of the top phase without substantially penetrating into and migrating through that phase. On the other hand, when the vinyl layer is applied by laminating a preformed vinyl film to the multiphase backing, a higher porosity, less dense top phase is employed.
Where the wallcover backing is intended for use as a coatable base, it has been found that the top phase preferably should consist of either natural cellulosic fibers, synthetic fibrid-type materials such as synthetic wood pulp, or mixtures thereof. Both the natural cellulosic fibers and the synthetic wood pulp provide a very tight fibrous web exhibiting low porosity and smooth surface characteristics. In practice, it is generally preferred that a mixture of the natural cellulosic fibers and the synthetic wood pulp be employed since the natural cellulosic fibers will provide a greater affinity for the latex binder solution used in accordance with the present invention. However where a different binder system is employed having a greater affinity for the hydrophobic synthetic pulp material, then up to 100 percent synthetic pulp may be used. Sheet materials containing a top phase of 100 percent synthetic pulp are typically weak and excessively tight thereby increasing the drainage time of the suspension during the papermaking process and requiring more expensive binder compositions in order to facilitate handling during subsequent coating operation. Consequently, it is preferred that the amount of synthetic pulp-like fiber constitute less than 90 percent by weight of the total fiber content of the top phase of the multiphase nonwoven web material and preferably between about 50 percent and 85 percent by weight on a dry weight basis.
The synthetic wood pulp is a thermoplastic polyolefinic material having a structure similar to wood pulp. That is, it contains a microfibrillar structure comprised of microfibrils exhibiting a high surface area, as contrasted with the smooth rod-like fibers of conventional man-made organic fibers. The synthetic pulps, such a polyolefins, have a structure more closely resembling wood pulp, and therefore can be more readily dispersed within an aqueous dispersing medium to achieve excellent random distribution of the synthetic material during the papermaking operation. The fiber-like particles forming the synthetic pulp have a typical size and shape comparable to the size and shape of natural cellulosic fibers. They exhibit irregular surface configurations, and have a surface area in excess of 1 square meter per gram and may have surface areas of even 100 square meters per gram. The fibers found particularly advantageous are those made of the high density polyolefins of high molecular weight and low melt index. The polymeric materials preferable have a melt index below 0.1 and a viscosity average molecular weight greater than 40,000. In fact the average molecule weight of the material typically is at least 500,000 and preferably greater than 800,000. There pulp-like fibers, such as polyethylene, polypropylene and mixtures thereof, have a fiber length well suited to the papermaking technique, e.g., in the range of 0.4 to 2.5 mm. with an overall average length of about 1 to 1.5 mm. Typical examples of these materials are the polyolefins sold by Crown Zellerbach Corporation under the designation "SWP" and "FYBREL", by Solvay and Cie under the designation "PULPEX" and by others.
Since the pure polyolefin particles are hydrophobic and have a surface tension that does not permit water wettability, the material obtained commercially is frequently treated to improve both wettability and dispersibility in the aqueous suspensions. The amount of wetting agent is however relatively small and generally is less that about 5 percent by weight, e.g., about 3 percent by weight and less. The chemically inert polyolefins are thermoplastic materials that become soft with increasing temperature, yet exhibit a true melting point due to their crystallinity. Thus, the synthetic polyolefin pulps exhibit a melting point in the range of 135° to 150° C. depending on the composition and surface treatment of the material. In this connection, the thermoplastic characteristic of the material is utilized by effecting at least a partial fusion of the synthetic wood pulp during the typical drying operation. The heat treatment causes the synthetic pulp to approach and somtimes exceed its fusion temperature. The presence of the synthetic pulp not only coats the synthetic fiber ends to a limited degree to avoid pilling during the plastisol coating operation, but also, via the fused characteristic of the material resulting from the drying, appears to provide a surface of hydrophobic character enabling the application of a thin continuous and relatively uniform vinyl layer. The diffused character of the synthetic wood pulp also assures a low porosity top phase that exhibits very low dusting characteristics and enhances the possibility of the plastisol coating sitting on the top of the semicontinuous fused film without excessively penetrating into the backing material, thus assuring a smooth and uniform exposed vinyl surface on the wallcover material.
Where the wallcover backing is to be used in connection with the lamination of a preformed vinyl film, it is preferred that the top phase of the backing exhibit substantially different characteristics and utilize substantially different fiber compositions than are used for coating backings. In this instance, it is generally preferred that thermoplastic heat sealable fibers be employed and that the fibers be of a character that exhibit an affinity for the vinyl film. In this way, the need for expensive adhesives and high energy usage for solvent removal is obviated. The preferred top phase for laminated vinyl layers contains a mixture of heat sealable thermoplastic fibers and natural cellulosic fibers. The thermoplastic material includes vinyl polymers and copolymers with the preferred material being Vinyon which is a copolymer of vinyl acetate and vinyl chloride. Where Vinyon is employed, up to about 90 percent of the fiber content of the top phase consists of such fibers with the remaining fibers being cellulosic fibers. Typically, amounts of thermoplastic fibers exceed 50 percent of the total fiber content of the top phase with the preferred amount of thermoplastic fiber exceeding the 65 percent level conventionally used in heat sealable webs. In fact amounts of about 75 to 85 percent have given the best results.
Although the proportion of fibers within the top phase and the bottom phase may vary substantially depending upon the particular end use of the multiphase wallcover backing it is generally preferred that the top phase constitute at least 5 percent and up to about 60 percent by weight of the total fiber content of the multiphase nonwoven sheet material. Typically, the top phase will constitute from about 25 to 45 percent of the total fiber content of the sheet.
The two phase sheet material preferably is dried in a conventional manner and then is treated with a latex binder and penetration inhibitor, which treatments may be conducted successively or simultaneously. Where they are conducted as separate operations, the sheet material is typically dried between each treatment; however, a single treatment with a solution containing both the binder and the inhibitor is preferred.
The latex binder system utilized is of the hydrophobic type and imparts to the web material the desired structural integrity required for wallcover backing. At the same time, the binder promotes adhesion of the backing with the vinyl covering placed thereon. The binder takes the form of an aqueous suspension or dispersion and preferably is comprised of an inherently hydrophobic and crosslinkable polymeric material that may include a small amount of surfactant in its commercial form. The specific latex suspension employed in accordance with the present invention may vary substantially depending upon the particular fibers used in the backing material; however, many of the hydrophobic latex binders used for nonwovens, such as the acrylics, polyvinyl chlorides, SFB's, vinyl ethylene latex systems and blends thereof can be effectively used. While the invention should not be limited to any specific binder material, it has been found that best results are achieved when using an internally stabilized acrylic latex emulsion of the type sold by B. F. Goodrich under the trademark "HYCAR 2600×120". This material is believed to be a latex with an polyethyl acrylate base.
The multiphase web material is also treated with a penetration inhibitor which, as mentioned, can be added to the latex binder and incorporated therein, or can be added as a separate and subsequent treatment. The penetration inhibitor should be a material that will provide the desired resistance to penetration and migration of the vinyl plastisol coating, as well as resistance to penetration of the wallpaper adhesive used to adhere the vinyl wallcover during application thereof to a suitable wall structure. In the preferred embodiment, the desired penetration resistance is achieved by utilizing a fluoro chemical treating agent commercially available. In this connection, it has been found that excellent results are obtained by using solutions and emulsions of metal complexed fluorinated salts and fluorinated polymeric treating agents that have been used commercially for resisting the penetration of aqueous fluids. One such material that has been found particularly useful for the laminating backing is the "Scotch Ban" brand fluorochemical treating agent sold under the designation "FC-824" by Minnesota Mining and Manufacturing. This resin emulsion penetration inhibitor typically may be combined with antistatic agents, extenders such as supplementary water repellent agents, buffers and the like and conventionally is applied by passing the dried binder-containing nonwoven fibrous web material through an aqueous emulsion of the penetration inhibitor and subsequently subjecting the treated sheet to a drying operation. A typical aqueous emulsion treating formulation would contain about 0.7 to 1.5 parts by volume and preferably 1.25 parts by volume of FC-824 concentrate as received from the supplier with each 100 parts of water and would be used at a treating bath temperature of about 120° to 150° F. Other fluoro chemical materials having similar characteristics include metal complex solutions such as FC-805, a solution of a chromium complex of N-ethyl-N-heptadecylfluoro-octane sulfonyl glycine. These are employed particularly on coating backing sheets. Other fluid repellant agents such as waxes, silicones, urethanes, sizing aids, parafin and the like may be used.
The penetration inhibitor is applied by dipcoating when used as either a separate treatment or when applied simultaneously with the application of the latex binder. When applied separately, a solution or emulsion containing lower concentrations of the treating material provide excellent results. When the penetration inhibitor is combined with the latex binder, the amount of inhibitor utilized may constitute from 1 percent to 5 percent solids based on the solids within the latex binder emulsion. The emulsion is adjusted so that the multiphase web material will pick up from about 25 to about 40 percent by weight of its final weight from the treating process. The preferred pick up rate is about 30 to 35 percent in order to provide the desired characteristics. However, when the backing is to be utilized in a laminating process rather than a coating process, less latex binder is required and typically is preferred so as not to interfere with the heatsealable character of the top phase of he multiphase web material used in the laminating process. However, a pick up of at least 15 to 18 percent should be obtained to provide the desired strippability for the backing.
The following examples are given for purposes of illustration only in order that the present invention may be more fully understood. These examples are not intended to in any way limit the practice of the invention. Unless otherwise specified, all parts are given by weight.
EXAMPLE 1
A two phase nonwoven web material was made on an inclined wire papermaking machine using two separate fiber furnishes. The first fiber furnish contained 80 percent by weight of a high cedar containing bleached Kraft pulp sold under the name "Crofton" and 20 percent by weight of polyethylene terephthalate fibers having a denier of 1.5 and a length of about 1/4 inch. This furnish was used to form the bottom phase of a two phase sheet material. The top phase was made from a fiber furnish containing 16 percent of the high cedar containing bleach Kraft pulp, 80 percent of a synthetic wood pulp sold under the name "PULPEX" and consisting primarily of polyolefin fibers and 4 percent by weight of flock. The sheet was formed so that the base phase consisted of about 70 percent by weight of the total multiphase sheet material and the top phase consisted of the remaining 30 percent based on the total fiber weight.
The resultant sheet material was dried and exhibited a basis weight of 20.1 pounds per ream (1.0 ounce per square yard). Using a single dip method, the sheet material was then treated with a latex binder dispersion of an ethylacrylate binder sold under the trade designation "HYCAR 2600×120". The dispersion contained about 5 percent of a chromium complex fluoro chemical sold under the designation "FC-805" by Minnesota Mining and Manufacturing. The solution also contained minor amounts of a melamine formaldehyde crosslinking agent, a defoamer, a fluorochemical stabilizer and ph adjuster. Treatment of the nonwoven material with the latex dispersion resulted in a pick up of 31.7 percent so that the total weight of the treated material after drying was 30 pounds per ream (1.5 ounce per square yard). The material was dried and then coated with a plastisol giving good plastisol coatability with very little migration. The percent penetration of the plastisol was 3 percent and the strippability was measured at 0.88 lbs/inch.
EXAMPLE 2
The procedure of Example 1 was repeated except that the fiber furnish was altered in the bottom phase. The same fibers were employed; namely, bleached Kraft pulp and polyester fibers. However, the amount of each fiber within the bottom phase was altered so that the content thereof was approximately equal; namely, 50 percent polyester fibers and 50 percent blached Kraft. The top phase remained unchanged and the weight of the resultant material was approximately the same. The two phase sheet material formed using the above mentioned fiber furnish was treated with the same latex/binder penetration inhibitor solution to provide a pick up of about 29 percent. After drying, the material was tested for coatability and was found to provide a good plastisol coatability with very little migration. The physical properties of the backing were similar to those of Example 1 but the sheet was thicker exhibited higher strength characteristics.
EXAMPLE 3
A heatsealable two phase wallcover backing was prepared using the same technique as in the previous examples. In this case, the base phase consisted of a fiber furnish having 56 percent bleached Kraft pulp, 37 percent polyester fibers and 7 percent of the synthetic wood pulp. The top phase consisted of 85 percent Vinyon fibers having a length of 1/2 inch and a weight of 3 dpf. and 15 percent unbleached Kraft pulp. The top phase constituted 38 percent of the total basis weight of the untreated material, which had a basis weight of 16.69 pounds per ream. Two phase heatseal web material was treated with a latex binder solution similar to that used in Example 1, except that the fluorochemical was changed to the polymeric emulsion sold under the designation "FC-824" by Minnesota Mining and Manufacturing. After dip treating the material within the latex binder suspension, the resultant product exhibited a pickup of 25 percent by weight and dry basis weight of 22.25 pounds per ream. The sheet material was then laminated to a preformed 8 mil. vinyl film by first heating the backing material to about 280° F. for 30 seconds in order to render the heatseal thermoplastic fibers tacky. The preformed film was then adhered to the backing with good results after 10-15 seconds at 280° F. under a compression of about 45 psi.
The sheet material was also tested with respect to strippability of the material from a test panel and was found to readily separate from the test panel leaving little or no fibers on the test panel from the backing material. The strippability was measured as 0.5 lbs/inch.
As will be appreciated by those skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosure can be made without departing from the teaching of the present invention.
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A wallcover backing for strippable vinyl wallcovering comprises a dimensionally stable unitary multistratum nonwoven fibrous web material that can be coated with or laminated to a vinyl layer. The backing material has a fibrous top phase adapted for secure nondelaminating engagement with the vinyl layer superimposed thereon and a fibrous base stratum integrated with the top phase and adapted for strippable adhering engagement with a wall or the like. The top phase constitutes at least 5 percent by weight of the web and has a smooth exposed surface for direct adhesion to the vinyl layer. The web includes about 15 to 45 percent by weight of a hydrophobic latex binder and contains an adhesive penetration inhibitor adapted to inhibit the migration of a wallcover adhesive into the fibrous web material and to promote uniform and full strippability of the web from the wall to which it is adhered.
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This is a division of application Ser. No. 123,903, filed Mar. 12, 1971, now U.S. Pat. No. 3,833,517.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an agent for subjecting fiber material of native cellulose to a pretreatment in alkaline treatment baths and to a process of treating such fiber material as well as to the thus treated fiber material.
2. Description of the Prior Art
Before bleaching, dyeing, printing fibers of native cellulose and fabrics made therefrom, such fibers and especially cotton are usually freed of their natural fatty, collenchymatous, pectin, and lignin substances, the residues of the seed coats, and the usually oily contaminations due to the spinning and weaving process. Such accompanying substances interfere with the above mentioned finishing processes.
Heretofore, such contaminations and impurities were eliminated by a treatment with alkaline agents such as with sodium carbonate and/or sodium hydroxide solutions whereby the fiber material was either boiled in open vessels or was scoured in closed vessels under pressure and at a temperature up to 135°C. The fiber material was treated for a period of time varying between a few minutes up to 5 or even 8 hours depending upon the type of the starting material and the process employed.
Usually suitable auxiliary agents or adjuvants such as alkali metal polyphosphates and/or wetting agents were added to such alkaline baths.
German Auslegeschrift No. 1,273,481 discloses a process of bleaching fiber material of native cellulose in the absence of oxidizing agents in which 4% to 13%, by weight, of sodium hydroxide and 1% to 4%, by weight, of alkali metal polyphosphates and/or amino polycarboxylic acids such as N-hydroxy ethylene diamino triacetic acid, o-cyclohexylene diamino tetraacetic acid, nitrilo triacetic acid, and ethylene diamino tetraacetic acid were added to the bleaching bath. However, these known methods of pretreating and finishing fiber material composed of native cellulose have many disadvantages. The most important disadvantage of these methods is that they affect and damage the fiber.
SUMMARY OF THE INVENTION
It is one object of the present invention to provide a process of pretreating fiber material of native cellulose in alkaline pretreatment baths which method is free of the disadvantages of the prior art methods and does not cause any substantial damage to the fiber.
Another object of the present invention is to provide a pretreatment and finishing agent for carrying out said method of pretreating and finishing fiber material of native cellulose in alkaline treatment and finishing baths.
Still another object of the present invention is to provide a bucking or soaking preparation useful in the bucking or boiling of fiber material of native cellulose.
A further object of the present invention is to provide pretreated or finished fiber material composed of or containing native cellulose fibers.
Other objects of the present invention and advantageous features thereof will become apparent as the description proceeds.
In principle the process according to the present invention comprises the addition of
I. an amino alkylene phosphonic acid of Formula I or its salts and especially its alkali metal salts to the boiling, bucking, and the like baths ##EQU1## In said formula R 1 and R 2 indicate the following groups and atoms:
a. R 1 and R 2 indicate groups of the Formula ##EQU2##
b. R 1 indicates the group of the Formula ##EQU3##
R 2 indicates a group of the Formula ##EQU4## wherein x indicates the numerals 2 and 3;
y indicates the numerals 0 to 4; while R and R 3 both are the group of the Formula ##EQU5## one of R and R 3 is the group of the Formula ##EQU6## and the other one is hydrogen or both R and R 3 indicate hydrogen; or
c. R 1 indicates the group of the Formula ##EQU7##
R 2 indicates the group of the Formula ##EQU8## wherein R 4 indicates hydrogen and R 5 indicates alkyl especially lower alkyl, such as methyl or ethyl; or
R 4 and R 5 together form alkylene, while
z indicates the numerals 0 and 1, and
R 6 indicates hydrogen or the group ##EQU9## Such amino alkylene phosphonic acids to be added to the bucking, boiling, and other finishing baths are, for instance,
amino tris-(methylene phosphonic acid);
diethylene triamino penta-(methylene phosphonic acid);
1,2- and 1,3-propylene diamino tetra-(methylene phosphonic acid);
ethylene diamino tetra-(methylene phosphonic acid);
1,2-cyclohexane diamino tetra-(methylene phosphonic acid);
1-amino methyl cyclopentylamino-(2)-tetra-(methylene phosphonic acid);
dipropylene triamino penta-(methylene phosphonic acid);
1,3-diamino-2-propylene tetra-(methylene phosphonic acid)
and the like compounds.
II. As nitrogen-free compounds there have proved to be useful for the purpose of the present invention 1-hydroxy alkane-1,1-diphosphonic acids.
Alkali metal salts and derivatives of said phosphonic acid compounds can, of course, also be used.
Best results are achieved when adding such alkylene phosphonic acid compounds to the finishing bath in an amount between about 0.3 g./l. to about 5 g./l., preferably in an amount of about 2 g./l.
Furthermore, it has been found that mixtures of said phosphonic acid compounds with other organic and/or inorganic complexing or sequestering compounds such as amino polycarboxylic acids, for instance, ethylene diamino tetraacetic acid, nitrilo triacetic acid, gluconic acid, citric acid, and others can also advantageously be used for the present purpose. An especially advantageous agent is the mixture of the above-mentioned phosphonic acids with alkali metal polyphosphates. When using the alkali metal polyphosphates alone in such alkaline finishing baths, the disadvantage is encountered that the alkali metal polyphosphates are hydrolyzed in the alkaline bath at a bath temperature between 90°C. and 140°C. so that they at least partly lose their power of forming complex compounds with interfering cations such as calcium, magnesium, and the like ions which are usually present in the fiber material to be treated. Such loss of complexing or sequestering power does not take place when amino alkylene phosphonic acid compounds are present in the bath.
On the other hand, the effectiveness of the amino alkylene phosphonic acids is considerably enhanced by the presence of alkali metal polyphosphates of the Formula II
me.sub.n .sub.+ 2 P.sub.n O.sub.3n .sub.+ 1 II
wherein
Me indicates an alkali and
n may be a numeral between 2 and infinite, preferably between 2 and 24. Such alkali metal polyphosphates are, for instance,
sodium pyrophosphate,
sodium tripolyphosphate,
sodium tetrapolyphosphate,
Graham salt,
and other soluble polyphosphates of various chain lengths.
By such a combination the dispersive and emulsifying power, and especially the ability of removing and carrying along dirt from the fiber material, i.e. the dirt-solving power, are greatly enhanced. It is understood that many variations in the proportion of phosphonic acid and other complexing or sequestering agents are possible. Best results are achieved, however, with a proportion of the phosphonic acid to the other complexing agent which is between 0.25 and d4.0 : 1.
Wetting agents can also be added to the soaking, bucking, and the like finishing baths. For this purpose all conventional wetting agents may be used provided they are effective in alkaline media and are compatible to the phosphonic acid and the complexing or sequestering agents. Anionic as well as nonionogenic wetting agents or mixtures thereof can be used for this purpose. Alkylaryl sulfonates, fatty acid condensation products, protein cleavage products, and the like as well as their salts can be used as anion active agents. Suitable non-ionogenic compounds are, for instance, adducts of ethylene oxide to fatty alcohols, fatty acid amides, alkylphenols, and others.
The important advantage achieved by the use of an agent according to the present invention is to be seen in the fact that the pre-treatment and finishing operation is carried out under conditions not substantially affecting the cellulose chain of the raw cotton. The mean degree of polymerization (M.P.) is only slightly reduced by treating the cellulose fiber according to this invention. The degree of whiteness is remarkably high and the ash content is relatively low.
As is known, chemical attacks upon the native cellulose have the effect that the cellulose chain is split up into larger or smaller fragments depending upon the type of the chemical agents used and the intensity of their action upon the cellulose. The M.P.-values of the treated cellulose were determined because they represent practically the only way of numerically indicating the extent of cleavage of the cellulose chain. Such M.P.-values are given in the following examples.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following examples illustrate the present invention without, however, being limited thereto.
The starting material for Examples 1 and 2 is a raw cotton material with an M.P.-value of 2,030, a degree of whiteness of 50.3 %, determined by means of the Elrepho apparatus with a filter R 46, and an ash content of 0.37 %. The raw cotton was treated in a bath (water of a degree of hardness of about 17°; ratio of goods to bath 1 : 10) for 3 hours. The bath had the composition as given hereinafter in Examples 1 and 2.
EXAMPLE 1
Comparative treatment with conventional complexing agents. 1 g./l. of ethylene diamino tetraacetic acid;
1 g./l. of sodium pyrophosphate;
2 g./l. of a wetting agent consisting of a mixture of an ethoxylated fatty alcohol, an alkyl aryl sulfonate, and an alkyl sulfonate; and
7.7 g./l. of sodium hydroxide.
The raw cotton treated as described hereinabove in said bath has an M.P.-value of 1,800, its degree of whiteness is 77 %, and its ash content 0.68 %.
EXAMPLE 2
Treatment according to the present invention.
0.7 g./l. of amino tris-(methylene phosphonic acid);
1.3 g./l. of sodium tripolyphosphate;
1.0 g./l. of a wetting agent consisting of a mixture of a phenylsulfonate with an ethoxylated fatty alcohol;
1.0 g./l. of sodium dithionite Na 2 S 2 O 4 ; and
20 cc./l. of 50 % sodium hydroxide solution.
The raw cotton treated with such a solution has an M.P.-value of 2,030, a degree of whiteness of 75 %, and an ash content of 0.68 %.
As is evident from Examples 1 and 2, the ash content is about the same in both examples, the degree of whiteness is not appreciably different, but the M.P.-value in the comparative Example 1 is reduced by 230 units, while, when proceeding according to the present invention, the M.P.-value of the raw cotton remains the same. These comparative tests thus clearly show that the cellulose chain in raw cotton, when subjected to a pre-treatment according to the present invention, remains substantially unchanged.
The starting material used in the following Examples 3 to 7 was a raw cotton with an M.P.-value of 2,100, a degree of whiteness of 56% (determined with the Elrepho apparatus with filter R 46) and an ash content of 0.40%. The raw cotton was treated in a bath (ratio of good to liquor: 1 : 10) at 100°C. for 21/2 hours. The bath had the composition as given in Examples 3 to 7. The examples indicated by (a) were carried out with distilled water while the examples indicated by (b) used water of a degree of hardness of about 17°.
EXAMPLES 3a and 3b
1 g./l. of ethylene diamino tetra-(methylene phosphonic acid);
1 g./l. of sodium dithionite;
1 g./l. of sodium tripolyphosphate;
1 g./l. of a wetting agent consisting of a mixture of a phenyl sulfonate with an ethoxylated fatty alcohol;
20 cc./l. of 50% sodium hydroxide solution. The cotton treated according to Example 3a, i.e. with distilled water, has an M.P.-value of 2,050. Its degree of whiteness is 72%, and its ash content 0.12%. The cotton treated according to Example 3b, i.e. with tap water, has an M.P.-value of 2,000, its degree of whiteness is 76%, and its ash content 0.15%.
EXAMPLES 4a and 4b
0.7 g./l. of 1-hydroxyalkane-1,1-diphosphonic acid;
1.3 g./l. of sodium tripolyphosphate;
1.0 g./l. of sodium dithionite;
1.0 g./l. of a wetting agent consisting of a mixture of a phenyl sulfonate with an ethoxylated fatty alcohol; and
20 cc./l. of a 50% sodium hydroxide solution.
The cotton treated according to Example 4a, i.e. with distilled water, has an M.P.-value of 2,025, a degree of whiteness of 77%, and an ash content of 0.12%. The cotton treated according to Example 4b, i.e. with tap water, has an M.P.-value of 2,000, its degree of whiteness is 75%, and its ash content 0.13%.
Raw cotton with the same properties as described hereinabove was treated according to the following Examples 5 and 6 under high temperature conditions, i.e. at 130°C. for 1 hour, whereby the amount of 50% sodium hydroxide solution was reduced to 10 ml./l. Otherwise, the composition of the treating agents was the same as in Examples 3 and 4. As in said examples, the examples designated by (a) were carried out with distilled water, while the examples designated by (b) used tap water of a degree of hardness of about 17°.
The treatment of the raw cotton with the treating agent according to Example 5(a) resulted in a cotton of an M.P.-value of 1,850, a degree of whiteness of 72%, and an ash content of 0.1%.
The treatment according to Example 5(b) resulted in a cotton of an M.P.-value of 2,000, a degree of whiteness of 71%, and an ash content of 0.25%.
When treating the cotton with the agent as given in Examples 4(a) and 4(b), the treated cotton has the following M.P.-values:
EXAMPLE 6(a)
M.p.-value 1,900;
degree of whiteness 73%;
ash content 0.1%.
EXAMPLE 6(b)
M.p.-value 2,000;
degree of whiteness 71%;
ash content 0.15%.
EXAMPLE 7
The same raw cotton was treated according to the known process with a bath which was considered as yielding optimum results and which contained per liter of distilled water
3.4 g. of ethylene diamino tetraacetic acid;
1.6 g. of sodium dithionite;
1.0 g. of a wetting agent consisting of an alkylene sulfonate, an alkyl aryl sulfonate, and ethoxylated fatty alcohols, and
20 cc. of a 50 % sodium hydroxide solution.
After treating the cotton with said bath at 100°C. for 21/2 hours, the M.P.-value of the treated cotton was 1,775, its degree of whiteness 75%, and its ash content 0.15%.
After a treatment at 130°C. for 1 hour, the M.P.-value was 1,750, the degree of whiteness 70%, and the ash content of 0.14%.
The starting material in the following Examples 8 to 10 was a cotton with an M.P.-value of 1,740 and a degree of whiteness of 48.8% (determined with the Elrepho apparatus with filter R 46). The cotton was heated in a bath (ratio of good to liquor: 1 : 10; hardness of the water: about 17°) at 100°C. for 3 hours. The bath composition was as given in Examples 8 to 10.
EXAMPLE 8(a)
7.7 g./l. of sodium hydroxide;
2.0 g./l. of a wetting agent consisting of a phenylsulfonate with an ethoxylated fatty alcohol.
EXAMPLE 8(b)
7.7 g./l. of sodium hydroxide;
2.0 g./l. of the wetting agent of Example 8a; and
1.0 g./l. of sodium dithionite Na 2 S 2 O 4 .
EXAMPLE 9(a)
1.0 g./l. of ethylene diamine tetraacetic acid;
1.0 g./l. of sodium pyrophosphate Na 4 P 2 O 7 ;
2.0 g./l. of the wetting agent of Example 8a; and
7.7 g./l. of sodium hydroxide.
EXAMPLE 9(b)
1.0 g./l. of ethylene diamine tetraacetic acid;
1.0 g./l. of sodium pyrophosphate Na 4 P 2 O 7 ;
2.0 g./l. of the wetting agent of Example 8a;
7.7 g./l. of sodium hydroxide; and
1.0 g./l. of sodium dithionite Na 2 S 2 O 4 .
EXAMPLE 10(a)
2.0 g./l. of ethylene diamine tetra-(methylene phosphonic acid);
2.0 g./l. of the wetting agent of Example 8a; and
7.7 g./l. of sodium hydroxide.
EXAMPLE 10(b)
2.0 g./l. of ethylene diamine tetra-(methylene phosphonic acid);
2.0 g./l. of the wetting agent of Example 8a;
7.7 g./l. of sodium hydroxide; and
1.0 g./l. of sodium dithionite Na 2 S 2 O 4 .
The following Table shows the M.P.-values of the treated cotton as well as its degree of whiteness:
Table______________________________________Example No. M.P. -value Degree of whiteness______________________________________Starting cotton 1740 48.8 %8a 670 67.1 %8b 1565 65.2 %9a 1230 71.1 %9b 1605 67.8 %10a 1495 68.4 %10b 1785 64.5 %______________________________________
These results clearly prove that treatment of cotton with an alkaline bath containing ethylene diamine tetra-(methylene phosphonic acid) according to the present invention considerably improves the M.P.-value of the treated cotton. For instance, while treatment with ethylene diamine tetraacetic acid without sodium dithionite (Example 9a) yields a cotton with an M.P.-value of 1230, the M.P.-value of cotton treated under the same conditions with the amino alkylene phosphonic acid has an M.P.-value of 1495, i.e. an improvement by 265, i.e. a very considerable decrease in the degradation of the cellulose chain.
When treating the cotton in the presence of sodium dithionite, the degradation of the cellulose chain is considerably reduced due to the sodium thionite preventing the oxidizing effect of atmospheric oxygen upon the cotton fiber. Treatment with an amino alkylene phosphonic acid according to the present invention (Example 10b) yields a treated cotton with an even higher M.P.-value than that of the starting cotton, namely with an M.P.-value of 1785 as compared with the initial M.P.-value of 1740. If no complexing agent is present in the treating bath, the M.P.-value is reduced to 1565 (Example 8b), as compared with 1740 of the starting cotton, while, if the complexing agent ethylenediamine tetraacetic acid is added, the M.P.-value of the treated cellulose fiber is increased only slightly, namely to 1605 (Example 9b). That the M.P.-value of cotton treated according to the present invention with the addition of sodium dithionite is even higher than that of the starting cotton is probably due to the fact that no degradation takes place and that the low molecular cellulose components are dissolved and removed during treatment.
The results given in all the preceding Examples 1 to 10 were obtained as mean values calculated each time from four determinations.
These results clearly show that on boiling and bucking experiments carried out by adding relatively small amounts of the phosphonic acids according to the present invention, the degradation of the cellulose chain as demonstrated by the M.P. values is so small that the treatment according to the present invention represents a noteworthy improvement of the heretofore used optimum mode of operation which causes considerable degradation of the cellulose. This improvement is not due solely to the sequestering power of the phosphonic acid added especially since the ash content and the degree of whiteness remain substantially unchanged.
The "Elrepho apparatus with filter R 46" used for determining the degree of whiteness is an electric remission photometer of the firm Carl Zeiss with a band elimination filter having its optimum transmission at 460 nm.
The M.P. value, i.e. the mean degree of polymerization value was determined according to the Cuoxam method as it is described, for instance, by J. J. Riphagen in "Melliand Textilberichte" 1971, pages 133 to 136. These values are also designated as "D.P.-values", i.e. degree of polymerization values.
The 1-hydroxy alkane-1,1-diphosphonic acid used in Examples 4a, 4b, and 6a, 6b was 1-hydroxy ethylene-1,1-diphosphonic acid. 1-Hydroxy propylene-1,1,3-triphosphonic acid has also proved to be effective.
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Alkaline baths for treating fiber material composed of or containing native cellulose such as cotton do not cause appreciable degradation of the cellulose chain when having added thereto amino alkylene phosphonic acids and/or 1-hydroxy alkane-1,1-diphosphonic acids or their salts.
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BACKGROUND OF THE INVENTION
[0001] A. Field of Invention
[0002] This invention pertains to the art of methods and apparatuses regarding the manufacture and assembly of tires, and more particularly to methods and apparatuses regarding the manufacture of pneumatic tires requiring increased lower sidewall durability.
[0003] B. Description of the Related Art
[0004] It is known that certain pneumatic tires, such as those suitable for use on an aircraft, are subjected to operating conditions which include relatively high internal pressures, relatively high speeds (often in excess of 300 kilometers per hour), and relatively high deflections. During the taxiing and taking off of an aircraft, the tire deflection may be more than 30%, and on landing may be 45% or more under impact conditions. Such relatively extreme pressures, loads, and deflections put the lower sidewall area of the tire adjacent the beads under severe tests. The high inflation pressures cause large tensile forces in this bead area while the high deflection rates cause high compressive forces in the axially outer portion of the bead area. These extreme operating conditions can tend to decrease the durable life of the lower sidewall and bead areas. As used herein, an “aircraft tire” or a “pneumatic tire suitable for use on an aircraft” is understood to mean a tire of a size and strength specified for use on an aircraft in either the Yearbook of the Tire and Rim Association, Inc., or the Yearbook of the European Tyre and Rim Technical Organization published in the year that the tire is manufactured.
[0005] Commonly, the number of plies (carcass plies) placed in the lower sidewall area of a pneumatic tire requiring increased lower sidewall durability, such as an aircraft tire, have been increased and additional reinforcement plies have been added in the bead area in order to increase rigidity and to decrease deformation of the pneumatic tire under load. Typically, both the carcass plies and the reinforcement plies are comprised of the same tire cord fabric. The tire cord fabric may consist of a pair of (ply) cords extending diagonally across the pneumatic tire. These ply cords may extend from a first bead structure to a second bead structure at about a 80°-90° angle with respect to the equatorial plane of the aircraft tire. Each individual ply cord of a particular ply may be at the same angle, but run in the opposite direction, with respect to the other individual ply cord.
[0006] Recently, it has become known to use a relatively high modulus tire cord fabric, such as aramid, in constructing both the carcass and reinforcement plies. The high modulus cords may be embedded in an elastomeric material and there may be a plurality of cord ends per inch of elastomeric material. The modulus of a material may generally be defined as the ratio of stress to strain within the linear elastic range of such material. The strain can be defined as the change in length of the material, as a result of the stress, divided by the original length of the material. As applied to tire fabric cord or cable, the cord modulus is the ratio of its longitudinal stress to the resulting strain within the elastic limit of the cord material. A ply of parallel cords also has a corresponding modulus. The ply modulus is equal to the cord modulus multiplied by the cord end count, which may be defined as the number of cord ends per inch, in the ply. Plies made of higher modulus cords (high modulus plies) are currently favored over plies made of lower modulus cords (low modulus plies). High modulus plies are of relatively lower weight and melt at a higher temperature than low modulus plies. The higher melting temperature results in the plies being more resistant to flat-spotting. A method of tire design using high modulus plies is provided in U.S. Pat. No. 6,427,741 titled AIRCRAFT TIRE, which is hereby incorporated by reference.
[0007] Although many known pneumatic tires requiring increased lower sidewall durability, such as an aircraft tire, work well for their intended purpose, they do have disadvantages. One disadvantage to using high modulus plies in the construction of aircraft tires is their lower fatigue compression durability as compared to low modulus plies. Lower fatigue compression durability of the plies may cause a premature removal of an aircraft tire from an aircraft liner. This premature removal results in a higher operating cost to the airlines and, may offset and reduced costs to the airlines resulting from the decreased weight of the high modulus plies.
[0008] What is needed then is a pneumatic tire with a higher fatigue compression durability without a significant increase in the overall weight of the tire. In providing this higher fatigue compression durability, it is desirable that the tire's footprint is not significantly reduced. Further, it is desirable to localize the compression loading of the pneumatic tire.
SUMMARY OF THE INVENTION
[0009] According to one embodiment of this invention, a pneumatic tire has a sidewall structure portion, a tread structure portion, a belt structure portion, and a carcass structure portion. The carcass structure portion has a bead core, an apex, and a carcass reinforcement portion. The carcass reinforcement portion has a first, a second, a third and a fourth high modulus up ply; a first and a second high modulus down ply; and, a first and a second low modulus chipper. The second low modulus chipper is axially outward from the second high modulus down ply and the first low modulus chipper is axially inward from the second high modulus down ply and axially outward from the first high modulus down ply. In another embodiment of the invention, the pneumatic tire comprises an aircraft tire.
[0010] According to another embodiment of this invention, a pneumatic tire has a sidewall structure portion, a tread structure portion, a belt structure portion, and a carcass structure portion. The carcass structure portion has a bead core, an apex, and a carcass reinforcement portion. The carcass reinforcement portion has a first, a second, a third and a fourth high modulus up ply; a first and a second high modulus down ply; and, a first and a second low modulus chipper. The second low modulus chipper is axially outward from the second high modulus down ply and the first low modulus chipper is axially inward from the second high modulus down ply and axially outward from the first high modulus down ply. The first high modulus up ply has a first turn-up portion, the second high modulus up ply has a second turn-up portion, the third high modulus Up ply has a third turn-up portion, and the fourth high modulus up ply has a fourth turn-up portion. The distance the first turn-up portion extends radially outward from the center of the bead core is about ⅓ of the diameter of the bead core. The distance the second turn-up portion extends radially outward from the center of the bead core is greater than ½ of the diameter of the bead core and less than the distance the third turn-up portion extends radially outward from the center of the bead core. The distance the third turn-up portion extends radially outward from the center of the bead core is greater than ½ of the diameter of the bead core and less than ½ of the radial height of the apex. The distance the fourth turn-up portion extends radially outward from the center of the bead core is about ¼ of the diameter of the bead core. The distance the first low modulus chipper extends radially outward from the center of the bead core is about ½ of the section height of the pneumatic tire. The distance the second low modulus chipper extends radially outward from the center of the bead core is greater than the radial height of the apex plus 1.5 inches and less than the distance the first low modulus chipper extends radially outward from the center of the bead core. The end of the second high modulus down ply is located a distance radially outward from the center of the bead core that is greater than the radial height of the apex plus about 1.0 inches. The end of the first high modulus down ply is located radially outward from the end of the second high modulus down ply. The first low modulus chipper may extend at least 0.5 inches radially outward from the end of the first high modulus down ply. The second low modulus chipper may extend at least 0.5 inches radially outward from the end of the second high modulus down ply. The radial distance between the end of the second low modulus chipper and the end of the first high modulus down ply may be at least 0.25 inches.
[0011] According to another embodiment of this invention, a pneumatic tire may have a sidewall structure portion, a tread structure portion, and a carcass structure portion. The carcass structure portion may have a first high modulus up ply, a first high modulus down ply, and a first low modulus chipper.
[0012] According to another embodiment of this invention, a pneumatic tire may have a sidewall structure portion, a tread structure portion, and a carcass structure portion. The carcass structure portion may have a first high modulus up ply, a first high modulus down ply, a second high modulus down ply, and a first low modulus chipper. The first low modulus chipper is axially outward from the first high modulus down ply and axially inward from the second high modulus down ply.
[0013] According to another embodiment of this invention, a pneumatic tire may have a sidewall structure portion, a tread structure portion, and a carcass structure portion. The carcass structure portion may have a first high modulus up ply, a first high modulus down ply, a first low modulus chipper, and a second low modulus chipper. The second low modulus chipper is axially outward from the second high modulus down ply.
[0014] According to another embodiment of this invention, a pneumatic tire may be an aircraft tire having a sidewall structure portion, a tread structure portion, and a carcass structure portion. The carcass structure portion may have a first high modulus up ply, a first high modulus down ply, and a first low modulus chipper. The first high modulus up ply and the first high modulus down ply comprise an aramid and the first low modulus chipper comprises a nylon.
[0015] According to another embodiment of this invention, a pneumatic tire may be an aircraft tire having a sidewall structure portion, a tread structure portion, and a carcass structure portion. The carcass structure portion may have at least a first high modulus up ply, at least a first high modulus down ply, and a first low modulus chipper. The high modulus up plies and the high modulus down plies comprise an aramid and the first low modulus chipper comprises a nylon.
[0016] According to another embodiment of this invention, a pneumatic tire may be an aircraft tire having a sidewall structure portion, a tread structure portion, and a carcass structure portion. The carcass structure portion may have at least a first high modulus Up ply, at least a first high modulus down ply, a first low modulus chipper, and a second low modulus chipper. The at least a first high modulus up plies and the at least a first high modulus down plies comprise an aramid and the first and the second low modulus chippers comprise a nylon. The first low modulus chipper is axially outward from all of the high modulus down plies and the second low modulus chipper is axially inward from at least one of the first high modulus down plies.
[0017] According to one embodiment of this invention, a method of constructing a pneumatic tire includes applying an inner liner, applying a carcass structure, applying a belt package, and applying a tread structure. The carcass structure has a carcass reinforcement portion that has a first high modulus up ply, a first high modulus down ply, and a first low modulus chipper.
[0018] According to another embodiment of this invention, a method of constructing a pneumatic tire includes applying an inner liner, applying a carcass structure, applying a belt package, and applying a tread structure. The carcass structure has a carcass reinforcement portion that has a first high modulus up ply, a first high modulus down ply, a second high modulus down ply, a first low modulus chipper, and a second low modulus chipper. The second low modulus chipper is axially outward from the second high modulus down ply and the first low modulus chipper is axially inward from the second high modulus down ply and axially outward from the first high modulus down ply.
[0019] According to another embodiment of this invention, a method of constructing a pneumatic tire includes applying an inner liner, applying a carcass structure, applying a belt package, and applying a tread structure. The carcass structure has a carcass reinforcement portion that has a first high modulus up ply, a first high modulus down ply, a second high modulus down ply a first low modulus chipper, and a second low modulus chipper. The second low modulus chipper is axially outward from the second high modulus down ply and extends at least 0.5 inches radially outward from the end of the second high modulus down ply. The first low modulus chipper is axially inward from the second high modulus down ply and axially outward from the first high modulus down ply and extends at least 0.5 inches radially outward from the end of the first high modulus down ply.
[0020] According to another embodiment of this invention, a method of constructing a pneumatic tire includes applying an inner liner, applying a carcass structure, applying a belt package, and applying a tread structure. The carcass structure has a carcass reinforcement portion that has a first high modulus Up ply, a first high modulus down ply, a second high modulus down ply a first low modulus chipper, and a second low modulus chipper. The second low modulus chipper is axially outward from the second high modulus down ply and extends at least 0.5 inches radially outward from the end of the second high modulus down ply. The first low modulus chipper is axially inward from the second high modulus down ply and axially outward from the first high modulus down ply and extends at least 0.5 inches radially outward from the end of the first high modulus down ply. The radial distance between the end of the second low modulus chipper and the end of the first high modulus down ply is at least 0.25 inches.
[0021] One advantage of this invention is that the pneumatic tire has a higher fatigue compression durability than that of a pneumatic tire comprised entirely of high modulus plies without a significant increase in the overall weight of the vehicle tire. The invention may instead result in a weight savings of as much as 15% over the conventional low modulus pneumatic tire. For example, the inventor has discovered that the inventive tire could yield a decrease in tire weight of about 50 pounds as compared to a tire (1400×530R23 40 pr 235 mph, 300 lbs) comprised of all low modulus materials. By ensuring that the weight of an inventive pneumatic tire suitable for use on an aircraft is not significantly increased, any savings resulting from the aircraft tire's higher fatigue compression durability is not negated by other factors, for example, higher fuel expenditures, resulting from the increased weight of the aircraft tire. Further, any additional increase in the weight of the aircraft tire is contrary to the aircraft tire design parameter for minimizing the weight of the airliner.
[0022] Another advantage of this invention is that the invention's higher fatigue compression durability significantly reduces the occurrence of premature removal of an aircraft tire from an aircraft. A higher fatigue compression durability increases the number flexes an aircraft tire may endure prior to a significant increase in the risk of tire failure resulting from the compression forces occurring during taxiing, take-off, and landing.
[0023] Still other benefits and advantages of the invention will become apparent to those skilled in the art to which it pertains upon a reading and understanding of the following detailed specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The invention may take physical form in certain parts and arrangement of parts, embodiments of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof and wherein:
[0025] FIG. 1 is a cross-sectional view of a pneumatic tire taken in an axial plane showing one embodiment of this invention.
[0026] FIG. 2 is an enlarged cross-sectional view of a part of the crown and upper sidewall region of the pneumatic tire shown in FIG. 1 .
[0027] FIG. 3 is an enlarged cross-sectional view of a part of the lower sidewall and bead region of the pneumatic tire shown in FIG. 1 .
[0028] FIG. 4 is a diagrammatical view of the part of the lower sidewall and bead region of the pneumatic tire shown in FIG. 3 .
[0029] FIG. 5 is a block diagram of a method of building an pneumatic tire in accordance with one embodiment of the invention.
DEFINITIONS
[0030] The following terms may be used throughout the descriptions presented herein and should generally be given the following meaning unless contradicted or elaborated upon by other descriptions set forth herein.
[0031] “Aircraft Tire” means a tire of a size and strength specified for use on an aircraft in either the Yearbook of the Tire and Rim Association, Inc., or the Yearbook of the European Tyre and Rim Technical Organization published in the year that the tire is manufactured. Generally, an aircraft tire has a laminated mechanical device of generally toroidal shape, usually an open-torus having beads and a tread and made of rubber, chemicals, fabric, and perhaps steel or other materials.
[0032] “Apex” means a wedge of elastomeric material placed beside (radially above the bead or bead core) the bead (or bead core) that supports the bead-area and minimizes flexing in the bead-area.
[0033] “Axial” and “axially” means lines or directions that are parallel to the axis of rotation of the tire.
[0034] “Bead” or “bead core” means that part of the tire comprising an annular tensile member wrapped by ply cords and shaped, with or without other reinforcement elements such as flippers, chippers, apexes or fillers, toe guards and chafers to fit the design rim.
[0035] “Belt” means at least two layers of plies of parallel cords, woven or unwoven, underlying the tread, unanchored to the bead, and having both left and right cord angles in the range from 17° to 33° with respect to the equatorial plane of the tire.
[0036] “Carcass” means the tire structure apart from the belt structure, tread, undertread, and sidewall rubber over the plies, but including the beads.
[0037] “Chafers” refers to narrow strips of material placed around the outside of the bead to protect cord plies from the rim, distribute flexing above the rim, and to seal the tire.
[0038] “Chipper” means a reinforcement structure located in the bead portion of the tire.
[0039] “Circumferential” means circular lines or directions extending along the surface of the sidewall perpendicular to the axial direction.
[0040] “Cord” means one of the reinforcement strands of which the plies in the tire are comprised.
[0041] “Crown” refers to substantially the outer circumference of a tire where the tread is disposed.
[0042] “Equatorial Plane (EP)” means the plane perpendicular to the tire's axis of rotation and passing through the center of its tread.
[0043] “Flipper” means an additional reinforcement (usually fabric) that is placed around the bead/apex and, usually, between the bead/apex and the carcass ply.
[0044] “Footprint” means the contact patch or area of contact of the tire tread with a flat surface at zero speed and under normal load and pressure.
[0045] “Inner” means toward the inside of the tire.
[0046] “Modulus” or “stress-strain ratio” means the modulus of elasticity of a material or the rate of change of strain as a function of stress. For purposes of this patent, a low or lower modulus material refers to a material with a modulus of elasticity less than 19 Giga Pascal (GPa) and high or higher modulus material refers to any material having a modulus of elasticity greater than 19 GPa.
[0047] “Nominal Rim Diameter” means the average diameter of the rim flange at the location where the bead portion of the tire seats.
[0048] “Outer” means toward the tire's exterior.
[0049] “Ply” means a continuous layer of rubber-coated parallel cords.
[0050] “Radial” and “radially” mean directions radially toward or away from the axis of rotation of the tire.
[0051] “Section Height” means the radial distance from the nominal rim diameter to the outer diameter of the tire at its equatorial plane.
[0052] “Shoulder” means the upper portion of sidewall just below the tread edge.
[0053] “Sidewall” means that portion of a tire between the tread and the bead area.
[0054] “Tenacity” means the stress expressed as force per unit linear density of an unstrained specimen (gm/tex or gm/denier), (usually used in textiles).
[0055] “Tread” means a molded rubber component which, when bonded to a tire casing, includes that portion of the tire that comes into contact with the road when the tire is normally inflated and under normal load.
DETAILED DESCRIPTION OF THE INVENTION
[0056] Referring now to the drawings wherein the showings are for purposes of illustrating embodiments of the invention only and not for purposes of limiting the same, FIG. 1 shows a pneumatic tire suitable for use as an aircraft tire 10 including a carcass structure 50 that may comprise high modulus up and down plies and a low modulus chipper that may be “sandwiched” or in between the high modulus up plies, made in accordance with one embodiment of this invention. While the tire shown is an aircraft tire, it is understood that the invention may be practiced with respect to tires intended for other applications also, such as passenger vehicle tires, light truck or sport utility vehicle tires, truck tires, agricultural tires, tires used on construction equipment, or on any type of tire chosen with sound engineering judgment. The aircraft tire 10 may comprise a tread structure 20 , a belt package 24 , a pair of sidewall structures 40 a, 40 b, and the carcass structure 50 . The tread structure 20 may be located in the crown of the aircraft tire 10 and may extend circumferentially about the aircraft tire 10 . The tread structure 20 may be a molded rubber, ground-engaging component and may provide traction for the aircraft tire 10 .
[0057] With reference now to FIGS. 1-2 , the belt package 24 may be arranged between the carcass structure 50 and the tread portion 30 . The belt package 24 may be characterized by a plurality of plies of parallel cords, or belt layers, woven or unwoven, and unanchored to a bead core 62 . In one embodiment, the belt package 24 may comprise, for example, six zigzag belt plies 26 a, 26 b, 26 c, 26 d 26 e, and 26 f and two spiral wound belt layers 28 a, 28 b. The spiral wound belt layers 28 a, 28 b may be positioned radially outward from the zigzag belt layers 26 a - 26 f. The number and type of belt layers comprising the belt package 24 may vary according to the specific tire construction.
[0058] With reference now to FIG. 1 , the sidewall structures 40 a, 40 b may extend radially inwardly from the axially outer edges 22 a, 22 b of the tread structure 20 and terminate at their radial extremities in a bead portions 60 a, 60 b of the carcass structure 50 . The sidewall structures 40 a, 40 b may have upper portions 42 a, 42 b and lower portions 44 a, 44 b. The upper portions may be located radially inward of the tread structure 20 and radially outward of a maximum section width MSW of the aircraft tire 10 . The lower portions 44 a, 44 b may be radially inward of the maximum section width MSW and radially outward of the bead portions 60 a, 60 b.
[0059] With reference now to FIGS. 1 , 3 - 4 , the carcass structure 50 may be cord-reinforced and may extend circumferentially about the aircraft tire 10 and may extend axially from the bead portion 60 a to the bead portion 60 b. The carcass structure 50 may comprise the bead portions 60 a, 60 b, an inner-liner 52 , and a carcass reinforcement structure 70 . The inner-liner 52 may be radially inward from the carcass reinforcement structure 70 and may surround an air chamber (not shown) formed by the aircraft tire 10 when mounted on a suitable rim (not shown). The inner-liner 52 may be generally air impervious and may extend from bead portion 60 a to bead portion 60 b.
[0060] With continued reference to FIGS. 1 , 3 - 4 , the bead portions 60 a, 60 b may each comprise a bead core 62 , and an apex 64 . The bead core 62 may be an annular inextensible structure and may comprise a circular cross section that may extend circumferentially around the aircraft tire 10 . In another embodiment, the bead portions 60 a, 60 b may comprise a plurality of bead cores, for example two (2) or three (3) and may comprise various cross-sectional shapes such as hexagonal or oval. The bead portions 60 a, 60 b may comprise any number of bead cores or any cross-sectional shape chosen with sound engineering judgment. The apex 64 may be located directly adjacent to and radially outward from the bead core 62 . The apex 64 may comprise an elastomeric material and may have substantially the shape of a triangle.
[0061] With continued reference to FIGS. 1 , 3 , and 4 , the carcass reinforcement structure 70 may comprise a plurality of carcass plies 72 . The plurality of carcass plies 72 may be comprised of high modulus cords or cables, for example, aramid or steel, or any other high modulus material having similar properties, or a combination of such high modulus materials, chosen with sound engineering judgment. Such high modulus cords may comprise any suitable denier and any suitable twist and may be treated to increase their bond strength to rubber. Additionally, aramid cords may be coated with an adhesive or an adhesive/epoxy combination.
[0062] With continued reference to FIGS. 1 , 3 , and 4 , the plurality of carcass plies 72 may comprise up plies (also known as inner plies) and down plies (also known as outer plies). In one embodiment, the carcass reinforcement structure 70 may comprise a first up ply 74 , a second up ply 76 , a third up ply 78 , and a fourth up ply 79 as well as a first down ply 80 , and a second down ply 82 . In another embodiment, the carcass structure 70 comprises one up ply and one down ply. The carcass reinforcement structure 70 may comprise any number of up plies and down plies chosen with sound engineering judgment. The plurality of carcass plies 72 may be positioned such that the first up ply 74 is the axially innermost carcass ply, the second up ply 76 may be positioned axially outward from the first up ply 74 and axially inward from the third up ply 78 , and the fourth tip ply 79 may be positioned axially outward from the third up ply 78 . The down plies may be positioned such that the first down ply 80 is positioned axially outward from the fourth up ply 79 and axially inward from the second down ply 82 . The second down ply 82 may be the axially outermost carcass ply.
[0063] With continued reference to FIGS. 1 , 3 , and 4 , the up plies 74 , 76 , 78 , and 79 may extend radially inward along the axially inner side of a bead core 62 . The up plies 74 , 76 , 78 and 79 may bend around the bead core 62 and begin to extend radially outward along the axially outer side of the bead core 62 and may form a first, second, third, and fourth turn-up 74 a, 76 a, 78 a, and 79 a. The first, second, third, and fourth turn-ups 74 a, 76 a, 78 a, and 79 a may extend to any point chosen with sound engineering judgment. In one embodiment of the invention, the first turn-up 74 a may extend to a point radially outward from the reference line XX′. The distance H 1 B that the first turn-up 74 a extends radially outward from the reference line XX′ may be determined to be equal to ⅓ of a bead core diameter A. In another embodiment of the invention, the second turn-up 76 a may extend to a point radially outward from the reference line XX′ (A/3). The distance H 1 C that the second turn-up 76 a extends radially outward from the reference line XX′ may be determined to be greater than ½ of the bead core diameter A but less than a distance HID that the third turn-up 78 a extends radially outward from the reference line XX′ ((A/2)<H 1 C<H 1 D). In another embodiment of the invention, the third turn-up 78 a may extend to a point radially outward from the reference line XX′. The distance HID that the third turn-up 78 a extends radially outward from the reference line XX′ may be determined to be greater than ½ of the bead core diameter A but less than the a distance equal to ½ of an apex height D corresponding to the distance that a radially outermost point AA of the apex 64 extends radially outward from the reference line XX′ ((A/2)<H 1 D<(D/2)). In yet another embodiment of the invention, the fourth turn-up 79 a may extend to a point radially outward from the reference line XX′. The distance H 1 A that the fourth turn-up 79 a extends radially outward from the reference line XX′ may be determined to be equal to ¼ of the bead core diameter A (A/4).
[0064] With continued reference to FIGS. 1 , 3 , and 4 , the down plies 80 , 82 may extend radially inward along the axially outer side of the up plies 74 , 76 , 78 and 79 . The down plies 80 , 82 may extend such that the ends of the down plies 80 , 82 are situated radially above the reference line XX′. The down plies 80 , 82 may extend such that their ends are positioned at any point chosen with sound engineering judgment. A first chipper 85 may be axially inward from the first down ply 80 and axially outward from the second down ply 82 thereby separating the first down ply 80 and the second down ply 82 . A second clipper 84 may be axially outward from the first down ply 80 such that the first chipper 85 and the second chipper 84 may be said to “sandwich” the first down ply 80 . The first chipper 85 and the second chipper 84 may be low modulus chippers. In one embodiment of the invention, the Up plies 74 , 76 , 78 , and 79 and the down plies 80 , 82 may be comprised of an aramid and the first chipper 85 and the second chipper 84 may be comprised of a nylon. The ends of the first chipper 85 and the second chipper 84 may be positioned at any location chosen with sound engineering judgment. In one embodiment of the invention, the end of the first chipper 85 may be located a distance H 2 A radially above the reference line XX′. The distance H 2 A may correspond to a value that is less than ½ of the section height SH of the aircraft tire 10 (H 2 A<(SH/2)). In another embodiment of the invention, the end of the second chipper 84 may be located a distance H 2 B radially above the reference line XX′. The distance H 2 B may correspond to a value that is greater than the apex height D plus 1.5 inches but less than the distance H 2 A ((D+1.5″)<H 2 B<H 2 A).
[0065] With continued reference to FIGS. 1 , 3 , and 4 , in one embodiment of the invention, the end of the second down ply 82 may be located a distance EP 2 above the reference line XX′. The distance EP 2 may correspond to a value that is greater than the apex height D plus 1.0 inches (EP 2 >(D+1.0″)). In another embodiment of the invention, the end of the first down ply 81 may be located a distance EP 1 above the reference line XX′. The distance EP 1 may correspond to a value that is greater than the distance H 2 A and is also greater than the distance EP 2 (EP 1 >H 2 A, EP 1 >EP 2 ). In one embodiment of the invention, the first down ply 80 may comprise an overlap portion OL 1 in which the first chipper 85 overlaps or covers the first down ply 80 . In another embodiment of the invention, the second down ply 82 may comprise an overlap portion OL 2 in which the second chipper 84 overlaps or covers the second down ply 82 . In one embodiment of the invention, the first and second overlap portions OL 1 , OL 2 may be at least 0.5 inches. The first and second overlap portions OL 1 , OL 2 may comprise any amount of overlap chosen with sound engineering judgment. The end of the second chipper 84 and the end of the first down ply 80 may be separated by a distance G. In one embodiment of the invention, the distance G between the end of the second chipper 84 and the end of the first down ply 80 may be at least 0.25 inches. The end of the second chipper 84 and the end of the first down ply 80 may be separated by any distance chosen with sound engineering judgment.
[0066] With reference now to FIGS. 1-5 , a method for manufacture of an aircraft tire according to one embodiment of the invention will generally be described. Two stage tire building utilizing either a first stage tire drum in combination with a second stage tire drum or a single drum that can be moved from a first stage position to a second stage position, is well known. The first stage may comprise the step of building a band for the carcass structure 50 that includes the inner-liner 52 and the carcass reinforcement structure 70 . Band building is well known in the art. One method of band building may comprise the use of a belt or a collapsible drum to which the inner-liner 52 may be applied. The inner-liner 52 may be applied in the form of a continuous sheet followed by the application of the up plies 74 , 76 , 78 and 79 . The up plies 74 , 76 , 78 and 79 may be applied offset from each other with respect to the inner-liner 52 . Following the application of the up plies 74 , 76 , 78 and 79 , the bead cores 62 may be applied followed by the apex 64 . In one embodiment, the up plies 74 , 76 , 78 and 79 may then be turned around the bead cores 62 in order to form their respective turn-ups 74 a, 76 a, 78 a, and 79 a.
[0067] With continued reference to FIGS. 1-5 , the up plies 74 , 76 , 78 and 79 , may be mechanically folded over the bead cores 62 and the apex 64 . Next, the first down ply 80 may be applied followed by the application of the first low modulus chipper 85 . The second down ply 82 may then be applied followed by the application of the second low modulus chipper 84 . The first chipper 85 and the second chipper 84 and the first and second down plies 80 , 82 may be positioned offset from each other to allow for their respective ends to extend to their respective points as described above. The low modulus first chipper 85 and the low modulus second chipper 84 may be turned atop of the up plies 74 , 76 , 78 and 79 . In another embodiment of the invention, the second down ply 82 and the second low modulus chipper 84 may be applied prior to the first down ply 80 and the first low modulus chipper 85 . Following the application of the down plies 80 , 82 and the low modulus chippers 84 , 85 , the sidewall structures 40 a, 40 b may be applied. A second stage may include assembling the tread structure 20 together with the belt package 24 and combining them with the carcass structure 50 and the sidewall structures 40 a, 40 b assembled in the first step, utilizing known methods to form the uncured, or green, aircraft tire 10 .
[0068] Various embodiments have been described, hereinabove. It will be apparent to those skilled in the art that the above methods and apparatuses may incorporate changes and modifications without departing from the general scope of this invention. It is intended to include all such modifications and alterations in so far as they come within the scope of the appended claims or the equivalents thereof.
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A pneumatic tire may use a combination of high modulus and low modulus plies to provide increased fatigue compression durability without significantly increasing the weight of the tire.
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RELATED PATENT APPLICATIONS
This invention is a non-provisional patent application based on the previously filed Provisional application of the same name and the same Inventors:
Provisional patent filed to US PTO on 2 Jan. 2014 No. 61/923,022.
BACKGROUND OF THE INVENTION
The invention is a safety device used to prevent a practitioner of an aquatic sport of platform diving from injury caused by unanticipated or unwanted contact with a part of the platform after clearing the surface of the platform and commencing the inertial phase of the dive or another skill.
In the sport of platform diving, after commencement of the dive, the athlete is in free fall movement and has limited control of the dive trajectory. A miscalculation on the part of the athlete (resulting for instance in insufficient horizontal speed away from the platform at the moment of the take-off) can result in a part of the athlete's body coming into unwanted or unanticipated contact with the platform. Such contact may result in an injury to the body of the athlete.
A method and apparatus of preventing altogether or reducing the severity of the injury to the athlete's body in the above described situation is invented and described in this patent application.
BRIEF SUMMARY OF THE INVENTION
The method of injury prevention is to deploy a padding made of soft protective material between the platform and the athlete's body after the takes-off. Should the athlete's trajectory accidentally intersect with the platform after the take-off (for instance due to miscalculation on the part of the athlete), the deployed padding would partially absorb the shock of the collision between the platform and the athlete's body and spread the impact force along the padding's thickness. After the initial contact of the athlete with the padding is made, the padding starts to compress and generate a gradually increasing stopping force that reduces the peak acceleration of the athlete's body and diminishes the risk of scratches, bruises, fractures, concussions, or other injuries to the athlete's body that could have resulted from collision with unprotected surface of the platform. The padding is deployed through the use of the described and claimed apparatus.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 . DIVING PLATFORM WITH DEPLOYED PADDING
Showing the platform and the padding deployed to cover the top and forward part of the platform after commencement of the dive.
FIG. 2 . DIVING PLATFORM (PADDING NOT DEPLOYED)
Showing the platform and the padding position prior to deployment. In this illustration it can be seen that prior to deployment the padding is off the platform and is not hindering the use of the platform surface during preparation and commencement of the dive.
FIG. 3 . SPRING COIL (DISASSEMBLED FROM THE APPARATUS)
The spring coil is used as the force source in the embodiment of the invention, shown separately from the frame.
FIG. 4 . ASSEMBLED FRAME SHOWING ACTUATOR AND SPRING COIL (PADDING REMOVED).
The illustration is showing the frame with spring coil and actuator installed. Padding is not shown (it is placed on top of the frame).
FIG. 5 . PADDING WITH GUIDING STRIPS AND DISTANCE CONTROL RODS ATTACHED
The padding assembly with guiding strips and distance control rods, shown upside down.
FIG. 6 . PART OF FRAME SHOWING TRIGGER AND ACTUATOR
The illustration shows part of the frame furthest from the platform and the trigger latch (machined from aluminum block). In the deployed position the latch prevents the actuator from being pulled toward the platform by the spring.
FIG. 7 . APPARATUS (MOBILE VERSION), PARTS IDENTIFIED
The illustration shows the assembled apparatus installed on the mobile platform. The padding is in deployed position. Some of the major parts of the apparatus are identified.
FIG. 8 . APPARATUS IN THE LOADED STATE PRIOR TO DIVER TAKE-OFF (FRONT VIEW—ACTUAL SWIMMING POOL INSTALLATION)
Illustration showing actual swimming pool installation of the invention prior to diver take-off, shot from the front of the platform.
FIG. 9 . APPARATUS IN THE PROCESS OF DEPLOYMENT (FRONT VIEW—ACTUAL SWIMMING POOL INSTALLATION)
Illustration showing actual swimming pool installation of the invention after diver take-off, shot from the front of the platform.
FIG. 10 . APPARATUS IN THE LOADED STATE PRIOR TO DIVER TAKE-OFF (BACK VIEW—ACTUAL SWIMMING POOL INSTALLATION)
Same as FIG. 8 , shot from the back of the platform
FIG. 11 . APPARATUS IN THE PROCESS OF DEPLOYMENT (BACK VIEW—ACTUAL SWIMMING POOL INSTALLATION)
Same as FIG. 9 , shot from the back of the platform
FIG. 12 . APPARATUS IN THE DEPLOYED STATE (ACTUAL SWIMMING POOL INSTALLATION)
Actual swimming pool installation shot from the back of the platform after deployment.
FIG. 13 . APPARATUS (MOBILE VERSION) PRIOR TO DIVER TAKE-OFF
The diver is standing on the mobile platform in preparation to the take-off. The apparatus is in the loaded state.
FIG. 14 . APPARATUS (MOBILE VERSION) IN THE DEPLOYED STATE
The apparatus (mobile version) is deployed. The diver has taken off from the mobile platform.
FIG. 15 . RECEIVER
The receiver is a part of control device intended to receive control signal from the transmitter and initiate the deployment. The illustration shows the receiver circuitry board and the battery pack that powers the receiver.
DETAILED DESCRIPTION OF THE INVENTION
The injury prevention apparatus (the invention) has two distinct states, “loaded” and “deployed”.
In the “loaded” state ( FIGS. 2, 8, 10, 13 ) the padding resides on the apparatus frame. In the embodiment of the invention the apparatus is mounted off the platform, not hindering in any way the athlete's use of the platform surface for the purpose of performing the preparation to the dive and the dive itself. In the second state, deployed ( FIGS. 1, 12, 14 ), the apparatus engages so that the top surface of the platform is covered with protective padding. The material of the padding ( FIG. 5, 7 ) in the described embodiment is reticulated polyurethane foam, but other materials can be used as well that provide the same impact-adsorption properties, including natural or synthetic fibres.
In the “deployed” state ( FIG. 1, 12, 14 ) the padding covers the top and (partially) front platform surface and is ready to cushion the impact resulting from an accidental collision of the athlete with the platform. In order to deploy the apparatus (to transition from state “loaded” to state “deployed”, FIGS. 11, 9 ) the padding material is moved from its loaded position on top of the frame to the top surface of the platform by an application of a mechanical force to the padding. In the described embodiment of the invention the mechanical force for deployment is generated by a stretched coiled spring ( FIGS. 3, 4 ). The force can be provided by a number of other means, including (but not exclusively) by an electric motor, electric magnet/solenoid, a pneumatic device, or other source of mechanical energy.
To minimize the disturbance to the athlete during the diving procedure prior to the take-off, the embodiment of the invention keeps the padding on the apparatus frame in the “loaded” state. The frame is securely fastened to the platform side with the mounting system consisting of a steel plate attached to the platform with stainless steel screws. The mounting system allows for quick detachment of the apparatus from the platform for inspection, repairs, or for storage when not in use. The mounting system is not considered a major part of the invention.
To increase the speed and accuracy of the deployment, the embodiment of the invention uses guiding strips and a set of distance control rods (stopping rods) attached to the padding that improve the directional accuracy of the deployment and control the distance of travel of the padding along the platform during the deployment ( FIGS. 5, 7 ). The guiding strips serve the additional purpose of reduction of the friction between the platform and the padding, thus increasing deployment speed and reducing the padding material wear and tear. The stopping rods prevent the padding from moving more than a set distance along the frame during deployment. Other variants of the apparatus may use other mechanisms to control the deployment distance, such as wire, thread, or rods in different configurations, or not use any distance control mechanism at all, relying on the regulation of the applied mechanical force and friction to set the padding deployment position. Likewise, other variants of the invention may have guiding strips of a different kind, or not have them at all. These additional elements are not considered as a major part of the invention.
Even though it is envisioned that in the majority of cases the apparatus will be attached directly to the platform side (at the 90% angle to the direction of the dive, FIG. 1 ), there is a variant of the apparatus construction where the frame is attached to a mobile platform made for instance of wood ( FIGS. 7, 13, 14 ). In the mobile variant the platform itself does not need to be modified to permanently install the apparatus. Instead the apparatus attached to the mobile platform is simply placed on the surface of the platform ( FIGS. 13, 14 ). The diver using the apparatus has to then launch him/herself from the mobile platform as opposed to launching from the platform surface directly ( FIG. 13 ). Both installation versions (mobile and installed on the platform) are covered by the invention claims.
The apparatus has the following material parts, given in the following list together with their respected embodiments as constructed by the inventors:
(1) Padding
The soft protective padding made of material having thickness and indentation load deflection (ILD) that is sufficient to absorb and cushion mechanical forces arising from the possible contact of the athlete with the springboard and reduce the peak accelerations of the diver's body parts caused by such contact.
In the concrete embodiment of the invention the padding ( FIGS. 5, 7 ) is cut as a solid block of reticulated polyurethane foam fitted with guiding strips and a couple of distance control rods (stopping rods) to improve the accuracy of deployment both in terms of deployment direction, deployment speed, and final position of the padding on the platform. The guiding strips ( FIG. 5 ) allow the padding to slide along the rails during deployment and reduce the friction between the padding and the platform when the padding moves onto the platform. The distance control rods ( FIGS. 5, 7 ) cause the padding to stop at a precise position on the platform: when the padding is moved along the frame and onto the platform as far as the stopping rods allow it, the padding is stopped because distance control rods cannot move through the opening in the frame past the set distance ( FIG. 7 )
The concrete shape of the padding (concrete block of polyurethane) or the additional position control devices (stopping rods and guiding strips) are not claimed as major feature of the invention. Other shapes of padding are possible as well as other improvements or modifications that increase accuracy of deployment of the padding on the platform.
(2) Force Source
The force source is the component that generates the mechanical force that causes the padding to move onto the springboard surface during deployment. In the embodiment of the invention the force source is a coil spring ( FIGS. 3, 4 ) that is manually stretched (loaded) prior to deployment.
Other variants of the invention may use a linear (stepper) electric motor, pneumatic component, linear electromagnetic solenoid, rotational electric motor, or other force source. The particular source of mechanical energy chosen by the implementer is not considered to be a major differentiating feature.
(3) Actuator
The actuator is the part of apparatus that transmits the mechanical force generated by the force source to the padding to cause it to be deployed. The embodiment uses a plastic shuttle with a pusher plate that freely moves along the frame tubes. The pusher plate attached to the shuttle pushes the padding along the frame and onto the diving platform itself ( FIGS. 4, 6, 7 ). The actuator is affixed to the spring coil (the force source) and thus release of the previously stretched coil causes the actuator to push the padding along the frame and the apparatus to be deployed. The particular actuator design is not considered to be a distinguishing feature of the implementation.
(4) Frame
The frame is the part that holds together the major components of the apparatus, providing the means of mechanical stability to the assembly and allowing the apparatus to be firmly connected to the platform. The embodiment of the invention uses an aluminum frame made of two aluminum square tubes ( FIGS. 4, 6, 7 ). One of the frame functions is to limit the movement of the actuator to just one dimension, perpendicular to the front of the diving platform.
The particular details of the frame construction is not considered to be a major feature of the invention.
(5) Control Device
The control device is the element of the apparatus that initiates the deployment process. In the embodiment of the invention, the control device further consists of
a) a trigger machined from aluminum as a catch or latch ( FIG. 6 ) that holds the actuator in a fixed position prior to deployment and thus prevents the stretched spring coil release prior to the moment of deployment;
b) a miniature electric servo motor (not shown in the drawings) connected to the trigger with a swivel arm that provides effort necessary to release the trigger at the moment of deployment;
c) remote radio receiver powered by an electrical battery pack ( FIG. 15 ) that upon detecting release signal, provides power to the electric motor;
d) remote radio transmitter (not shown in the drawings) that generates and transmits the release signal to the receiver.
In the embodiment of the invention the deployment is controlled by a radio transmitter (d) operated by the person supervising the dive such as a diving coach or diving instructor. The corresponding receiver is installed on the frame ( FIG. 15 ) and upon receiving the signal emitted by the transmitter causes the control signal to be sent to the servo motor (b). The mechanical force generated by the servo motor is transmitted to the trigger latch ( FIG. 6 ) via the swivel arm. The trigger latch is lifted, releasing the previously stretched coil. The coil contracts and transmits the stored mechanical energy to the actuator. The actuator pushes the padding along the frame, causing it to be deployed.
The exact deployment moment is decided by the dive coach or instructor. By observing the dive the coach can make a judgement call that the diver has taken off ( FIGS. 9, 11, 14 ), at which time the coach will activate the described apparatus by pushing corresponding button on the remote transmitter (d). In other embodiments the deployment can be triggered mechanically with a piece of string, electrically via attached wires, or by any other means suitable to transmit the signal to the apparatus.
In addition to the triggering the deployment manually, the deployment can be triggered by an automatic sensor including, but not exclusively, by an accelerometer device placed on the body of the diver, by a photoelectric or laser sensor, by a video camera fitted with image recognition, or by other automatic means without invalidating the claim. We claim that particular means of timely triggering the deployment of the device to be a minor feature of the invention.
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The invention's innovation in the field of safety of aquatic sport of platform diving is a method and apparatus to diminish the risk of the athlete's injury caused by an accidental collision with the platform after the take-off by timely activating a device that places a protective padding covering the top of the platform.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to computer systems and, more particularly, to a method of controlling capacitors which are provided on a computer chip to enhance power supply, allowing testing of the computer system to determine the effects of the on-chip capacitors and allowing selective disabling of the capacitors as necessary.
2. Description of the Related Art
The basic structure of a conventional computer system includes a central processing unit (CPU) or processor which is connected to several peripheral devices, including input/output (I/O) devices (such as a display monitor and keyboard) for the user interface, a permanent memory device (such as a hard disk or floppy diskette) for storing the computer's operating system and user programs, and a temporary memory device (such as random-access memory or RAM) that is used by the processor to store instructions and data during program execution. The processor itself includes many different circuits, and these circuits are often fabricated on separate chips (silicon substrates), and then interconnected by various means. Recently, chip-fabrication techniques have allowed these circuits to be formed from a single die as shown in FIG. 1. Several exemplary circuits are depicted in that figure, including a fixed-point circuit 2, a floating-point circuit 4, a storage-control circuit 6, an instruction-control circuit 8, and a data-control circuit 10, all formed on a single computer chip 12. These circuits contain the various registers and logic units which carry out program instructions. Fabrication of the circuits on a single chip has several advantages, including quicker processing speeds and a smaller chip size.
One problem that has emerged in consolidating so many different circuits on a single chip relates to the power supply for the circuits. With so many circuits on a single chip, there can be degradations in processor performance due to, e.g., lag times associated with switching of latches in the processor registers and logic units, i.e., from low-voltage states to high-voltage states. One approach that has been implemented to address this problem is the further inclusion of many capacitors (tens of thousands) arranged in banks and distributed across (i.e., formed on) the chip, such as the capacitor banks 14 shown in FIG. 1 which are respectively connected to the various circuits and to a power supply 16. Such an approach allows the capacitors to instantaneously supply power to the circuits in an improved manner, relieving some of the performance degradation problems.
The provision of on-chip capacitors raises further concerns, however, particularly capacitor reliability and performance issues. There are concerns regarding how the capacitors function during processor operation and what their impact might be on the chip's functionality. Presently, there is no way to analyze this impact under different operating conditions and applications, such as burn-in and system environment conditions and functional and self-test applications. There is also no way to disable the capacitors in cases of unreliability and adverse electrical impacts that may have been introduced by the provision of the capacitors. It would, therefore, be desirable to devise a method of testing the reliability of on-chip capacitors and of determining the impact of these capacitors on processor performance. It would be further advantageous if the method would allow selective testing of a particular bank or banks of the capacitors, and if the method were compatible with a means for disabling the capacitors in those situations where the capacitors were either unreliable or created an excessively adverse impact on processor performance. Such disabling of the capacitors would be particularly useful if the disabling could be achieved without having to initialize the chip in certain states, such as after a power-on reset condition.
SUMMARY OF THE INVENTION
It is therefore one object of the present invention to provide an improved computer chip having a multiplicity of on-chip capacitors used to enhance the power supply.
It is another object of the present invention to provide a method of testing such on-chip capacitors to determine their reliability and impact on operating conditions.
It is yet another object of the present invention to provide on-chip capacitors which may be entirely or selectively disabled.
The foregoing objects are achieved in a method of controlling a plurality of capacitors formed on a single substrate, generally comprising the steps of providing a plurality of transistors, each connected to a respective one of the capacitors, each of the transistors having a gate, and connecting each of the gates to a control circuit, the control circuit having means for selectively activating the gates to temporarily disable one or more of the capacitors. The control circuit can determine whether logic circuits which are connected to the capacitors are in a power-on reset mode, and disables all of the capacitors if the logic circuits are in the power-on reset mode. A plurality of fuses may be provided, each connected to a respective one of the capacitors, such that a given fuse can be blown to permanently disable a given one of the capacitors. The control circuit may include a multiplexer which receives inputs from the fuses and which further receives inputs from a register having a plurality of bits, such that a bit pattern may be loaded into the register, the bit pattern being used to determine which of the capacitors to selectively disable. The states of the fuses can further be loaded as a bit pattern into the register. Operating conditions of the logic circuits (such as temperature and performance) can be measured after disabling selected capacitors. Each capacitor can be sequentially disabled by sequentially activating a given one of the bits in the register.
The above as well as additional objectives, features, and advantages of the present invention will become apparent in the following detailed written description.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives, and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
FIG. 1 is a block diagram of a prior art computer chip having several circuit formed thereon, and several banks of capacitors which enhance the supply of power to the circuits;
FIG. 2 is a schematic diagram illustrating degating of an on-chip capacitor according to the present invention;
FIG. 3 is a schematic diagram depicting a circuit for selectively disabling one more banks of on-chip capacitors; and
FIG. 4 is a chart illustrating the logic flow in testing on-chip capacitors according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is directed to a computer chip having a plurality of on-chip capacitors used to enhance the supply of power to various circuits fabricated on the chip, such as the on-chip capacitors shown in FIG. 1. While the present invention may be applied to a system such as that shown in FIG. 1, the computer system is not necessarily conventional, i.e., it could include new hardware components as well, or have a novel interconnection architecture for existing components. Therefore, while the present invention may be understood with reference to FIG. 1, this reference should not be construed in a limiting sense.
On-chip capacitor gating control requires special consideration since on-chip capacitors have only recently been implemented in chip designs, and there is a need to determine how the capacitors function and what their impact is on the chip's functionality. The present invention provides a method of analysis of this impact under different operating conditions and applications, including burn-in and system environment conditions, as well as functional and self-test applications.
As shown in FIG. 2, in one embodiment of the present invention a transistor 20 is used to disable an on-chip capacitor 22 which is coupled to the power supply V dd (e.g., 2.5 volts) in such a manner as to enhance supply of the power to an on-chip circuit 24. The path (or connection) from capacitor 22 to ground is made through transistor 20. Transistor 20 is preferably an NMOS field-effect transistor, although other transistors could be used. The gate 26 of NMOS transistor 20 is used to control the capacitor as discussed further below. All of the capacitors in each capacitor bank on the chip can be so controlled via separate lines connected to the gates of respective transistors.
FIG. 3 depicts a control circuit 28 which can be used to control the disable input 18 to an on-chip capacitor 22 disable transistor 20.
The control circuit is essentially comprised of a three-input to one-output switch 32 referred to as a muxtiplexor, or MUX, and its output 50 controls the transistor 20 (shown in FIG. 2), typically wired through a repowering device 38 referred to as a buffer. MUX 32, along with buffer 38, is provided for each capacitor bank. Although only one is shown, it is understood that several may be provided, one per capacitor bank being controlled, e.g., if 32 banks of on-chip capacitors are provided, then 32 separate MUX components and buffer components are provided.
Three select inputs, namely the capacitor-disabled select 52, the permanently set, by fuse 34, select 54, and the programmable, by register 36, disable select 56, are the means to enable the three possible control mechanisms into multiplexor 32, which, respectively, are a fixed, permanently disabled input 30, a fuse input 34a from fuse 34, and a programmable register input 36a from programmable register 36. There is a unique, separate fuse 34 for each instance of MUX 32 that controls a unique and separate capacitor bank. Likewise, there is a unique, separate programmable register 36 for each instance of MUX 32 that controls a unique and separate capacitor bank.
In addition to the multiplexor 32, the control circuit 28 also depicts a second multiplexor 42 that provides the programmable register 36 with information for disabling the capacitors. Three select inputs, namely the serial data select 48, the fuse select input 58, and the hold select 60, are the means to enable into the register the corresponding programmable information 40, the permanently set, by fuse 34, information, or the retaining register information.
Further depicted in the control circuit 28 are five control circuit inputs, namely the manufacturing test serial data control input 64, the system diagnostic serial data control 66, the system power on reset control 68, the permanently set, by fuse 34, select 54, and the disable serial data control input 72.
Two additional programmable latches, namely the hold register value latch 46 and the selectable (programmable) control latch 44 are provided to create the select inputs to multiplexors 32 and 42.
The remaining component to list in control circuit 28 is the two-input to one-output multiplexor 62, which provides the mechanism for routing the serial data from the input to the programmable register, around the programmable register, to the serial data output of the control circuit 28, bypassing the programmable register 36 as well as the two programmable latches 46 and 44.
The primary control circuit output is the capacitor disable 74, which connects to the capacitor gate 20 control input 18. A secondary control circuit output 80, is the serial data from multiplexor 62, which connects the latch components of control circuit 28 into serial data shift register scan chains that are integral on the microprocessor circuits as in the prior art.
The steering of capacitor control information is derived from control circuit 28 inputs 64, 66, 68, 54, and 72, plus the programmable latches 44 and 46. The derived functions for the select inputs to multiplexors 32, 42, and 62 are based on boolcan logic. Beginning with multiplexor 32 select inputs, the fuse 34 input drives the multiplexor output 50 whenever the control circuit input 54, the permanently set, by fuse 34, select is asserted active. This assertion can be under mechanical or electrical means; for discussion purposes, it can simply be a relay or switch asserted by an experimenter. Consequently, for whenever input 54, the permanently set, by fuse 34, select is not being asserted, either the fixed, permanently disabled input 30 will be selected, or the programmable register input 36a will be selected. Control circuit 28 input for system power on reset 68 asserted, or the programmable latch 44 for "selectable control" 44a unasserted 78 will decide that permanently disabled input 30 to the multiplexor 32 drives the multiplexor output. Therefore, it follows that, whenever the permanently set, by fuse 34, select is not being asserted, and system power on reset 68 is not being asserted, and the selectable control latch 44 is being asserted, then the programmable register input 36a to multiplexor 32 drives the multiplexor 32 output 50.
Discussion follows in a manner similar to multiplexor 32 for the programmable register 36 input multiplexor 42. Whenever the control circuit input 64, the manufacturing test serial data control input, or control circuit input 68, the system power on reset control, are asserted, then the multiplexor 42 select enabling the serial data input 40 is asserted, and the programmable register receives its data from the serial data control circuit 28 input 40. The select enabling the serial data input 40 is also asserted whenever input 66 system diagnostic serial data control is asserted so long as the input 72, disable serial data, is not asserted. Given that the control inputs 64, 66, and 72 are not configured to enable the serial data input into multiplexor 42, then the programmable register input will be either the same programmable register content or the fuse 34 input, the deciding factor being whether the hold register value latch 46 is asserted or not, 46a. If the hold register value latch is asserted, then the programmable register input will be its own contents and thus maintain, or hold, its contents; otherwise, the value of fuse 34 will load into the programmable register.
Because the control circuit depicts the programming of the register 36 and the two MUX select control latches, 44 and 46, by means of serial data, otherwise known as a scan or shift mechanism, and because system diagnostic serial data shifting may be required while leaving unaffected the values set into register 36 and the two MUX select control latches, 44 and 46, the control circuit 28 input 72, disable serial data control, is required to be asserted after register 36, and the two MUX select control latches, 44 and 46, have been set by the system diagnostic serial data shifting. Further system diagnostic serial data shifting after input 72, disable serial data control, has been asserted and will route the serial data input 40 through the multiplexor 62 to secondary control circuit output 80, which would connect to the serial data input of another latch element in the system.
The foregoing scheme may further be understood with reference to the flowchart of FIG. 4. First, a determination is made of whether the permanently set, by fuse 34, input is asserted (82). If so, the capacitors are used according to which fuses have been preselected, i.e., according to whether or not a given fuse has been blown (84), and no further testing occurs. If the capacitors are not to be controlled by the fuse, then the next step (86) is to determine whether all of the capacitors are to be disabled, as would be the case if the power on reset input, 68, is asserted or the selectable control latch, 44, is not set. If capacitors are not to be controlled by the fuse 34, then all capacitor banks are disabled (88), and flow proceeds to the configuration complete check (120). If only a portion of the capacitor banks are to be disabled for testing, then the control circuit examines the states of the various control signals to determine if specially selected capacitor banks are to be tested based on the contents of register 36, or whether a preset condition of the capacitors (based on the states of the fuses) are to be used (90). If testing is to be performed using the preset conditions, then the fuse 34 input through MUX 42 is loaded (92) into register 36 and, again, flow proceeds to the configuration complete check. If preset conditions are not to be used, the control circuit next determines whether manufacturing test is to be performed (94), in which case, register 36 is set by the serial data (96). Moreover, in manufacturing test, one and only one of all the capacitor banks will be enabled while all others are disabled, and subsequently, the stand-by, or quiescent power supply current draw is measured (98). If excessive current is drawn (100), then fuse 34 for the corresponding capacitor bank is blown (102). If more capacitors are to be tested (104), then another register 36 is set up to enable one other, and only one other, capacitor bank (96).
If manufacturing test using register 36 is not desired, then the control circuit examines whether the system is in a power-on reset mode (110). If so, then each register 36 for each corresponding capacitor bank controlled is set to "disable" (112), and the circuit checks for the assertion of the system diagnostic serial shift input, 66.
When the system diagnostic serial shift is detected (114), the control circuit examines the states of the circuit input 72, the disable serial data shift control, to determine whether register 36 and the MUX select control latches 42 and 44 are to be set by shifting with serial data as well (116). Once the operator has loaded the pattern for selecting which capacitor banks will be enabled and which will be disabled (118), the configuration complete check is made (120). If the configuration is complete, then, based on the contents of the registers 36, the performance measurements, for instance, maximum processor-operating frequency, and operating conditions, such as temperature, are noted and recorded by the operator (122). If the operator chooses to continue analysis, the process proceeds to decision 114. When the system diagnostic serial shift is detected and the disable serial data shift control is not asserted (116), then a pattern may be loaded into the register (118) and, again, the configuration complete check is made (120).
After any measurements have been taken in step 122, the control circuit can further inquire as to whether any new patterns are to be used (124) in the testing of the capacitor banks. If so, flow control proceeds to decision 114 in order to check if the system diagnostic serial shift is being asserted.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiment, as well as alternative embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It is therefore contemplated that such modifications can be made without departing from the spirit or scope of the present invention as defined in the appended claims.
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A method of controlling a plurality of on-chip capacitors used to enhance power supply to logic circuits for a computer processor. The capacitors are each provided with transistors which temporarily disable the capacitors when an appropriate logic state is applied to the gate of the transistors. In this manner the effects of the capacitors upon system performance can be measured, and if a particular capacitor (or capacitor bank) is defective or presents an adverse impact, it can be permanently disabled by blowing fuses provided for each capacitor (or capacitor bank). The capacitors may be selectively disabled using a control circuit which has a multiplexer provided with a set of inputs from a register which contains a bit pattern that is used to determine which capacitors to disable. The register can be loaded with any pattern or with a pattern that corresponds to the states of the unblown fuses. Alternatively, all of the capacitors may be disabled, such as during power-on reset.
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TECHNICAL FIELD
The present invention relates to computer controlled television programming and, particularly, to the presentation of program guides listing subsequent television programs from which viewers may select subsequent or future television for viewing or recording under computer control, usually in the form of a television set top box.
BACKGROUND OF RELATED ART
The computer controlled set top box is usually connected to a provider/subscriber television system. The box contains the computer resources necessary to control the television program presentation on a typical television set or personal computer. Of course, all of the computer resources needed to control the television or personal computer display may be integrated into the television set, the personal computer or mobile device, such as a cellular telephone or personal digital assistant (PDA).
Television programming provided by the service provider often run into the hundreds of television programs available from hundreds of channels for any given time period. On-screen program guides have provided reasonable organization for the hundreds of television programs being offered. As shown in FIG. 1 , these programming guides have a scrollable vertical list of channels, each having a row of sequential time segments with each segment representing a television program scheduled for the time segment. Should the viewer desire more information about the television program in a particular time segment, the viewer may select or “click” on the listing for the television program and receive more information in the form of a synopsis, e.g. item 12 , FIG. 1 . This synopsis gives very limited information to the viewer. Often, this synopsis provides insufficient information to help the viewer decide between what may be several television program offerings that are of interest.
SUMMARY OF THE PRESENT INVENTION
The present invention provides the viewer, who is consulting the programming guide, with additional information that involves a comprehensive set of visual images. Preferably, the set of sequential images are stills or snapshots representative of portions of the television program.
Accordingly, the present invention provides a method for selecting segments of listed television programs in a displayed television scrollable program guide that comprises displaying a scrollable program guide having a vertical list of channels, each having a row of sequential future time segments, each segment representing a television program scheduled for the future time segment and enabling a viewer to select a segment in a channel sequence, wherein the television program represented by said segment will be shown at the scheduled future time.
In this environment, this invention provides for the display of one or more of said future time segments wherein each includes a sequence of still images in the represented television program with each still image representing a sequential point in the television program. The viewer is, thus, enabled to select one of the still images in the sequence of still images, wherein the television portion at the sequential point represented by the still image will be shown at the scheduled future time of the sequential point. The still images may be stills of video scenes in the portions of the programs represented by the stills.
In accordance with an aspect of the invention, a viewer will be enabled to select a portion of the television program for recording at said scheduled future time of said sequential point.
Provision may be made for enabling the viewer to select a still image to get further advance information about the program portion represented by the still image. This information may be in the same form as a conventional textual synopsis provided for the whole television program, but will just cover the portion represented by the still image.
In accordance with a significant aspect of the invention, the sequence of still images is in the form of a film strip of the video. The images in the strip may vary in length relative to the variations in length of the portions represented' by the images or frames in the strip.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a generalized view of a displayed program guide illustrating a standard textual synopsis of a listed television program upon viewer selection for more information;
FIG. 2 is the same generalized view of FIG. 1 with the addition of the video film strip in accordance with the present invention;
FIG. 3 is the view of FIG. 2 wherein three (3) stills in the strip have been selected for future viewing or recording;
FIG. 4 is a generalized view of the computer controlled system of the present invention organized wherein the service provider provides the film strip of the television program content;
FIG. 5 is a flowchart describing how the implementation system of the present invention provides and implements the film strip of the television program content; and
FIG. 6 is a diagrammatic illustration of an aspect of the present invention wherein there is displayed a sub-strip having a sequence of sub-images within the portion of the television program represented by a selected image in an initial film strip.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 , there is shown a generalized diagrammatic view of a displayed program guide 10 that may be presented on a television set or any personal computer display on which a television program may be viewed. The standard guide is a matrix wherein the scheduled television programs are shown in horizontal rows 11 representative of television channels. When a viewer wishes more information about a particular program, the viewer scrolls to the program scheduled at a particular time and usually clicks on an information button resulting in the display of textual synopsis 12 .
In the present invention, as shown in FIG. 2 , there is provided a film frame strip 13 of sequential still images from the television program content at sequential points in the program. Each frame 14 or 16 represents a portion of the television program at the frame point in the television program sequence. The viewer is, thus, provided with visual information that supplements the synopsis 12 . The viewer then has the option of selecting the entire television program for subsequent viewing or recording, or he may only select one or more of the television program portions represented by any of the frames in the film strips for future viewing or recording. As will be hereinafter described in greater detail, these film strips may conveniently be provided by the television service provider.
By way of example, for a typical one hour television program, a film strip of eight (8) snapshots or frames may be used. Thus, each frame may represent 7.5 minutes of the hour. This gives the viewer the option of selecting only some of the frames for subsequent viewing or recording. In FIG. 3 , the viewer has selected frames 15 , 17 and 18 in film strip 13 for such subsequent viewing or recording. Accordingly, the portion or segment of the television program represented by frames 15 , 17 and 18 will be subsequently viewed or recorded. It should be noted that while in this example, the television program segments represented by the frames in the strip have been of equal length, the segments need not be equal. This may be determined by the service provider sending the representative film strips to the viewers.
In a further aspect of the present invention, reference is made to FIG. 6 , which is a diagrammatic illustration of an aspect of the present invention wherein there is displayed a sub-strip having a sequence of sub-images within the portion of the television program represented by a selected image in an initial film strip. It may be the case, particularly with television programming that runs for several hours that each frame 17 in the initial film strip 13 may be set up so as to be further dividable into a sub film strip 19 wherein each frame 20 represents a segment of the portion of the television program represented by frame 17 . Like the initial film strips 13 , the sub film strips are set up and stored in the server of the service provider and are made available by the service provider as required by the viewer. It should also be noted that the service provider may provide a textual synopsis for each frame 17 , and sub frame 20 .
Now, with reference to FIG. 4 it will be described how the present invention may be implemented on any apparatus providing computer control of a television set so that the control programs of this invention may be operated with the equipment. The receiver 45 at the viewer's site receives the content input 46 from the service provider 48 . The service provider also provides the above-described film strips 50 . The apparatus shown connected to receiver 45 may be conveniently housed in a television set top box or integrated within a unitary television set.
The operations involved in the present invention are controlled by a data processing system under the control of a central processing unit 40 , which, in turn, is interconnected to various other components by system bus 42 . An operating system (OS) 22 that runs on processor 40 provides control and is used to coordinate the functions of the various components of the control system. The OS 22 is stored in Random Access Memory (RAM) 41 . The control programs for the functions, including those for displaying film strips and sub-scripts, and enabling the viewer to select the portions and segments represented by the frames of film scripts and sub-scripts for future viewing on the television sets of the present invention may be permanently stored in Read Only Memory (ROM) 13 and moved into and out of RAM to perform their respective functions. In the normal operation for real-time television program playing, the integrated incoming data stream, under CPU control, is applied to broadcast channel extractor 47 that extracts the data representative of the television program scheduled for the channel that the user has selected on a tuner (not shown) and applies the extracted data to a conventional television display adapter 28 to be displayed on the user's television set 29 .
When the incoming unitary data stream is to be recorded on a DVR, the signal is processed through a disk drive adapter 21 and stored on disk drives 20 . In the conventional operation of a DVR, the television program scheduled for a given channel at a given time is extracted by extractor 17 , in response to interrupt sensor and then stored on a disk drive 20 provided on the DVR. This individual program would be recorded and, thus, stored on the disk drive either in response to advance scheduling by the user for such a recording in accordance with the present invention based upon the selection of frames in the film strips and sub-strips.
Now, with reference to the programming shown in FIG. 4 there will be described how the system and programs of the present invention are set up. There is provided a scrollable standard program guide presented on a TV display of horizontal time segments and vertical programs listed channel by channel so that the viewer may choose programs for subsequent viewing or recording, step 60 . Provision is then made for the display of a video “film strip” of sequential still images each representing a portion of one of one of the listed television programs, step 61 . Provision is made for the viewer to select one of the still images to thereby select the television program portion represented by the still image for future viewing or recording, step 62 . Provision is also made for enabling the viewer to select a still image to access further information about the program segment represented by the selected still image, step 63 . Further provision is made for enabling the viewer to select a secondary film strip of still images, each of which is representative of a secondary portion of the program segment, step 64 . In addition, provision may be made for varying the length of still images within the original or secondary films strips, step 65 .
As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, including firmware, resident software, micro-code, etc.; or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit”, “module” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable mediums having computer readable program code embodied thereon.
Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared or semiconductor system, apparatus or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (“RAM”), a Read Only Memory (“ROM”), an Erasable Programmable Read Only Memory (“EPROM” or Flash memory), an optical fiber, a portable compact disc read only memory (“CD-ROM”), an optical storage device, a magnetic storage device or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus or device.
A computer readable medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electromagnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate or transport a program for use by or in connection with an instruction execution system, apparatus or device.
Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including, but not limited to, wireless, wire line, optical fiber cable, RF, etc., or any suitable combination the foregoing.
Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language, such as Java, Smalltalk, C++ and the like, and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the later scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (“LAN”) or a wide area network (“WAN”), or the connection may be made to an external computer (for example, through the Internet, using an Internet Service Provider).
Aspects of the present invention are described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer or other programmable data processing apparatus to produce a machine, such that instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified flowchart and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.
The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
The flowchart and block diagram in the Figures illustrate the architecture, functionality and operations of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustrations can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
Although certain preferred embodiments have been shown and described, it will be understood that many changes and modifications may be made therein without departing from the scope and intent of the appended claims.
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A viewer who is consulting a television programming guide with additional information that involves a comprehensive set of visual images. Preferably, the set of sequential images are stills or snapshots representative of portions of the television program.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a magnetic-attaching structure for a fan, and in particular to a fan that can be assembled conveniently via a magnetic-attaching structure.
[0003] 2. Description of Related Art
[0004] There are many kinds of circuit boards and electronic elements in a computer housing. When the computer is operating, the temperature in the computer housing will rise because of the heat from the chips on the circuit board and the electronic elements of integrated circuits. If the temperature in the housing goes beyond the maximum limit of the electronic elements, it will cause the electronic elements to fail and the computer may even break down. The computer housing therefore usually has heat-dissipating holes and is assembled with fans, so that the heat from the electronic elements during operation can be exhausted outside the computer housing through the heat-dissipating holes by the air convection of the fans.
[0005] A fan structure of prior art is shown in FIG. 1 . A fan body 10 a is formed with a through hole 11 a at each of its four corners, respectively. A computer housing 20 a has a plurality of fixing holes 21 a corresponding to the through holes 11 a, and a plurality of heat-dissipating holes 22 a . The fan body 10 a is assembled to the computer housing 20 a by screws 30 a that pass through the fixing holes 21 a and the through holes 11 a. Therefore, the fan body 10 a can exhaust heat outside the computer housing 20 a through the heat-dissipating holes 22 a.
[0006] However, the conventional fan structure can only be assembled at the position that is formed with the fixing holes 21 a . It also needs screws 30 a to screw the fan to the computer housing 20 a . Moreover, the air-exhausting and air-inhaling direction of the fan cannot be changed easily. The assembly steps of the fan are troublesome and the application scope is limited, meaning it cannot be assembled at other positions quickly and other fans cannot be added for enhancing heat-dissipating effectiveness.
[0007] Accordingly, the present invention aims to propose a magnetic-attaching structure for a fan that solves the above-mentioned problems in the prior art.
SUMMARY OF THE INVENTION
[0008] An object of the present invention is to provide a magnetic-attaching structure for a fan, which allows for fans to be assembled more conveniently and quickly, and also allows for more fans to be added where they are needed. The present invention does not require fixing holes for the fans, nor screws, and as such the user can assemble or add fans more easily to better meet their needs.
[0009] Another object of the present invention is to provide a magnetic-attaching structure for a fan, which can change the air-inhaling direction or air-exhausting direction of the fans quickly according to the user's requirements. A user can opt have the fan to inhale air or exhaust air, and the fixing manner is not limited and is more convenient.
[0010] To achieve the first object, the present invention provides a magnetic-attaching structure for a fan, including a fan body, and a magnetic unit mounted with the fan body.
[0011] To achieve the other object, the present invention provides a main housing, a magnetic unit, and a fan body that is magnetically attached to the main housing by the magnetic unit.
[0012] Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention can be fully understood from the following detailed description and preferred embodiment with reference to the accompanying drawings, in which:
[0014] FIG. 1 is a perspective view of a fan assembled with a computer housing of prior art;
[0015] FIG. 2 is an exploded perspective view of a magnetic-attaching structure for a fan of the first embodiment according to the present invention;
[0016] FIG. 3 is an assembled perspective view of a magnetic-attaching structure for a fan of the first embodiment assembled with a computer housing according to the present invention;
[0017] FIG. 4 is an assembled perspective view of a magnetic-attaching structure for a fan of the first embodiment assembled with a side board according to the present invention;
[0018] FIG. 5 is an assembled perspective view of a magnetic-attaching structure for a fan of the first embodiment assembled with another side board according to the present invention;
[0019] FIG. 6 is an assembled perspective view of a magnetic-attaching structure for a fan of the first embodiment assembled with another computer housing according to the present invention;
[0020] FIG. 7 is a perspective view of a magnetic-attaching structure for a fan of the second embodiment according to the present invention;
[0021] FIG. 8 is an assembled perspective view of a magnetic-attaching structure for a fan of the second embodiment assembled with a fan net according to the present invention;
[0022] FIG. 9 is an assembled perspective view of a magnetic-attaching structure for a fan of the second embodiment assembled with a filter according to the present invention;
[0023] FIG. 10 is a perspective view of a magnetic-attaching structure for a fan of the third embodiment according to the present invention;
[0024] FIG. 11 is a perspective view of a magnetic-attaching structure for a fan of the forth embodiment according to the present invention; and
[0025] FIG. 12 is a perspective view of a magnetic-attaching structure for a fan of the fifth embodiment according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] The following detailed description is of the best presently contemplated modes of carrying out the invention. This description is not to be taken in a limiting sense, and is made merely for the purpose of illustrating general principles of embodiments of the invention. The scope of the invention is best defined by the appended claims.
[0027] Reference is made to FIG. 2 . The present invention of a magnetic-attaching structure for a fan includes a fan body 10 and a magnetic unit 20 .
[0028] The fan can be an axial-flow fan, a centrifugal fan, or a cross-flow fan. In this embodiment, the fan is an axial-flow fan. The fan body 10 has a square-shaped frame 11 . The frame 11 is embossed with an indicating mark 12 on its top surface for indicating the air-inhaling direction and the fin-rotating direction. The indicating mark 12 can coordinate with the magnetic unit 20 , so that the user can easily identify the air-inhaling direction when assembling the fan body 10 . The fan body 10 has an exhausting side 13 and an inhaling side 14 at its front and rear ends, respectively. The exhausting side 13 is opposite to the inhaling side 14 . Air is taken into the fan body 10 from the inhaling side 14 , and is exhausted outside the fan body 10 from the exhausting side 13 . The exhausting side 13 and the inhaling side 14 of the frame 11 respectively form a plurality of magnet receiving parts 15 at their four corners that are symmetrical related to diagonal lines. The magnet receiving parts 15 are circle-shaped and form an opening at their front surfaces, respectively.
[0029] In this embodiment, the magnetic units 20 are circular permanent magnets, which are embedded and received in the openings of the magnet receiving part 15 to be fixed in the fan body 10 . Because the magnetic units 20 are magnetic, the exhausting side 13 and the inhaling side 14 of the fan body 10 can all be attached where required.
[0030] Reference is made to FIG. 3 . The computer housing 30 is made of iron. The computer housing 30 is formed with a plurality of heat-dissipating holes 31 at its rear end, which allows heat in the computer housing 30 to be exhausted out. The exhausting side 13 of the fan body 10 is attached magnetically to the computer housing 30 around the heat-dissipating holes 31 by the magnetic units 20 , and then the fan body 10 is mounted on the computer housing 30 . The heat in the computer housing 30 can be exhausted outside through the heat-dissipating holes 31 by means of the operation of the fan body 10 with cooling effect.
[0031] Reference is made to FIG. 4 . The computer housing has one side board 40 that is made of iron. The side board 40 is formed with a plurality of circular heat-dissipating holes 41 , which allow air outside the side board 40 to be taken in. The inhaling side 14 of the fan body 10 is attached magnetically to an inside surface of the side board 40 by the magnetic units 20 , and then the fan body 10 is mounted to the side board 40 . Air can be inhaled from the inhaling side 14 when the fan body 10 is operating. The cool air outside the side board 40 can be taken into through the heat-dissipating holes 41 of the side board 40 , which lowers the temperature inside the computer housing for fulfilling the cooling goal.
[0032] Reference is made to FIG. 5 . The computer housing has another side board 50 that is made of iron. The side board 50 forms a plurality of rectangular-shaped heat-dissipating holes 51 . The exhausting side 13 of the fan body 10 is attached magnetically to an inside surface of the side board 50 by the magnetic units 20 , and then the fan body 10 is mounted to the side board 50 . The heat in the side board 50 can be exhausted outside through the heat-dissipating holes 51 by means of the operation of the fan body 10 .
[0033] Reference is made to FIG. 6 . A computer housing 60 is formed with a plurality of ventilating holes 61 . The inhaling side 14 of the fan body 10 is attached magnetically to a section of the computer housing formed with the ventilating holes 61 by the magnetic units 20 , and then the fan body 10 is mounted with the computer housing 60 . The air outside the computer housing 60 can be taken in the computer housing 60 through the ventilating holes 61 for cooling by operation of the fan body 10 .
[0034] Reference is made to FIG. 7 . A fan body 70 has a rectangular-shaped frame 71 that is made of a magnet or an electromagnet. A magnetic unit 80 is formed integrally with the frame 71 of the fan body 70 . The frame 71 is embossed with an indicating mark 72 on its top surface for indicating the air-inhaling direction and the fin-rotating direction. The fan body 70 has an exhausting side 73 and an inhaling side 74 at a front surface and rear surface, respectively. The exhausting side 73 is opposite to the inhaling side 74 , and both can be attached magnetically via the magnetic units 80 as required by the user.
[0035] Reference is made to FIG. 8 . The inhaling side 74 of the fan body 70 is further attached magnetically to a fan net 90 , which is made of iron, by the magnetic unit 80 , and then the fan net 90 is mounted with the fan body 70 . The user therefore cannot touch the fins directly, and the net provides a protective function. The exhausting side 73 of the fan body 70 also can be attached as shown in FIGS. 3 to 6 . On the other hand, the fan net 90 , the exhausting side 73 , and the inhaling side 74 can be attached to any other position (as shown in FIGS. 3 to 6 ) as deemed appropriate by the user.
[0036] Please refer to FIG. 9 . The present invention can have a filter 100 attached to the inhaling side 74 of the fan body 70 by the magnetic unit 80 . The filter 100 has an iron rim 101 and a plurality of meshes 102 connected with the rim 101 . The filter 100 is attached to the inhaling side 74 for preventing impurities or dust in the air from being inhaled. The exhausting side 73 can be attached to another position for cooling.
[0037] Please refer to FIG. 10 . In this embodiment, the magnetic unit 20 of the present invention includes four magnets that are L-shaped and are embedded respectively to four corners of the fan body 10 . The fan body 10 is attached magnetically to the heat-dissipating holes 41 of the side board 40 by the magnetic unit 20 .
[0038] Please refer to FIG. 11 . In this embodiment, the magnetic-attaching structure for a fan of the present invention includes a main housing 30 ′, a magnetic unit 20 , and a fan body 10 .
[0039] The main housing 30 ′ can be a power supply, an emergency power supply, a personal computer, an industry computer, a server, an uninterruptible power supply, a disk array external enclosure, an external HDD enclosure, an external disc drive, a keyboard, a notebook heat sink, a housing of an overhead projector, or medical laboratory measuring instruments. In this embodiment, the main housing 30 ′ is a personal computer and has a shell 31 ′. The shell 31 ′ has eight accommodating portions 32 ′ adjacent to the heat-dissipating holes 311 ′. Each of the accommodating portions 32 ′ forms an opening at it's front surface, respectively.
[0040] The magnetic unit 20 includes eight permanent magnets, which are embedded and received in the opening of the accommodating portion 32 ′, and the magnetic unit 20 can be mounted to the shell 31 ′ of the main housing 30 ′.
[0041] The frame 11 of the fan body 10 can be made of iron or embedded with at least one iron sheet (not shown) therein, so that the fan body 10 can be attached magnetically to the main housing 30 ′ by the magnetic unit 20 on the shell 31 ′.
[0042] Please refer to FIG. 12 , the main housing 30 ′ has a magnetic or electromagnetic shell 31 ′. A magnetic unit 80 ′ is formed integrally with the shell 31 ′of the main housing 30 ′, and then the iron frame 11 of the fan body 10 can be attached magnetically to the main housing 30 ′ by the magnetism of the magnetic unit 80 ′.
[0043] As described above, the advantages of the present invention are listed as follows:
[0044] Firstly, the magnetic-attaching structure for a fan of the present invention is easier to assemble than conventional fans, which require many fixing holes and screws for attachment to the computer housing. The user can assemble the fan conveniently and quickly to wherever them deem heat-dissipation to be necessary, such as a housing of a power supply, a housing of an emergency power supply, a housing of a personal computer, a housing of an industrial computer, a housing of a server, a housing of a UPS (Uninterruptible Power Supply), a housing of a disk array external enclosure, a housing of an External HDD Enclosure, a housing of an external disc drive, a housing of a keyboard, a housing of a notebook heat sink, a housing of an overhead projector, or housing of medical laboratory measuring instruments, or other housing mounted with cooling fans. The application scope is very wide, and the user can add fans freely. The air-inhaling direction or air-exhausting direction can changed quickly. If the exhausting side is attached magnetically to the computer housing, the airflow direction is exhausted from the housing. All that is required to change the direction of the airflow is attaching the inhaling side of the fan to the computer housing. Conversely, the airflow direction can be changed from air-inhaling to air-exhausting.
[0045] While the invention has been described with reference to the preferred embodiments, the description is not intended to be construed in a limiting sense. It is therefore contemplated that the appended claims will cover any such modifications or embodiments as may fall within the scope of the invention defined by the following claims and their equivalents.
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A magnetic-attaching structure for a fan includes a fan body and a magnetic unit. The magnetic unit is mounted with the fan body, and then the magnetic-attaching structure for a fan can be easily assembled or changed so that the air-inhaling or air-exhausting directions are also changed. The fans can be assembled conveniently and quickly, and additional fans can be added as required. No fixing holes are needed for the fans, nor are screws needed to fix the fans in place. The user can assemble or add fans conveniently as suits their requirements.
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BACKGROUND OF THE INVENTION
[0001] 1. Technical Field of the Invention
[0002] The present invention relates to a method for producing a basic amino acid such as L-lysine known as an important additive for livestock feed or L-arginine or L-histidine useful as a drug such as an infusion solution (i.e., parenteral fluid) or the like.
[0003] 2. Related Art
[0004] In a conventionally known method for producing a basic amino acid by means of fermentation, sulfate ions or chloride ions (chlorine ions) have heretofore been generally used as counter anions so as to maintain electrical neutrality of a culture medium. These are supplied mostly in the form of ammonium sulfate as described in, for example, Japanese Patent Application Laid-Open Nos. 30985/'93, 244969/'93, and the like.
[0005] Meanwhile, a basic amino acid such as lysine or the like is often sold in the form of the chloride salt (hydrochloride) since it is difficult to crystallize a basic amino acid such lysine or the like in the free state. However, in the production method of a basic amino acid by means of fermentation, since a hydrochloride causes corrosion of a fermentation tank, or the like, a sulfate is often used for fermentation for the purpose of avoiding the corrosion of the tank.
[0006] In this case, however, since a basic amino acid product as such resulting from such fermentation is different in counter anion from a basic amino acid product (to be) placed in distribution, the counter anions (such as sulfate ions) are once removed from the basic amino acid salt produced by means of such fermentation, with the use of, e.g., an anion exchange resin and desired counter anions (such as chloride ions) are then added in the form of a free acid, whereby the target basic amino acid salt is produced. Such use of a resin, however, increases loads on environmental protection such as drainage resulting from use of the resin, and the like.
[0007] Further, since such use of a resin requires excess acid and alkali, a variety of by-products are also discharged in addition to the target amino acid salt.
[0008] In addition, when a basic amino acid such as lysine or the like is to be placed in distribution in the form of a solution-type amino acid feed additive, the solubility of the amino acid in the feed additive solution decreases due to the presence of counter anions, if present therein, so that the counter anions must be removed with the use of a resin in order to obtain an amino acid solution with a high concentration.
[0009] In the case of lysine as an example, lysine hydrochloride can be dissolved in water at 10° C. in an amount of at most 43 g in terms of lysine per 100 g of water, and lysine ½ sulfate can be dissolved in an amount of at most 68 g per 100 g of water. On the other hand, in the case of a solution having only lysine dissolved therein (a free lysine solution), the solution is alkaline in nature, and lysine can be dissolved therein in an amount of as much as 120 g per 100 g of water. In this connection, refer to Japanese Patent Application Laid-Open No. 256290/2000.
[0010] As could be understood from the above, removal of the counter anions from a basic amino acid solution is essential or indispensable to prepare a basic amino acid solution having a high concentration.
[0011] There has been known as a conventional method for purifying an amino acid fermentation broth with the use of an ion exchange membrane, a method (as disclosed in Japanese Patent Publication No. 7666/1960) in which the amino acid moiety in an aqueous solution of an amino acid salt is caused to pass through the ion exchange membranes with the use of an electrodialyser equipped with a plurality of cation exchange membranes and anion exchange membranes, the two kinds of ion exchange membranes being disposed alternately, whereby the amino acid is produced. The performance of the method, however, is not necessarily high in terms of electrical efficiency due to low mobility of organic molecules such amino acid or the like.
[0012] Further, in the case of a solution which contains a large amount of various organic metabolites and the like resulting from microbial fermentation, which, in turn, cannot pass through a cation exchange membrane and an anion exchange membrane, their concentrations become so significantly high at the surfaces of the ion exchange membranes that these organic metabolites are deposited or agglomerated and eventually accumulated on the surfaces of the ion exchange membranes to clog the membranes, which ends in making a continuous operation impossible disadvantageously.
SUMMARY OF THE INVENTION
[0013] [Problems to be Solved by the Invention]
[0014] It is an object of the present invention to provide a method for obtaining a basic amino acid solution having a high concentration within the concentration range in which crystals of a basic amino acid salt are not deposited, by removing the counter anions from a solution of the basic amino acid salt efficiently by use of electrodialysis.
[0015] [Means for Solving the Problems]
[0016] The present inventors have made extensive and intensive studies to achieve the above object and found that, in removing the counter anions of a basic amino acid by means of electrodialysis, when an alkali aqueous solution is added to a solution of the basic amino acid salt (solution to be subjected to electrodialysis) during the electrodialysis, the counter anions of the basic amino acid such as sulfate ions or the like can be efficiently removed to such degree that they remain in an amount of 40 mol % or smaller based on the amino acid. The present invention has been completed on the basis of these findings.
[0017] Accordingly, the present invention relates to a method for producing a basic amino acid solution which comprises subjecting a solution of a basic amino acid salt to electrodialysis with the use of an electrodialyser equipped with cation exchange membranes and anion exchange membranes in combination, wherein an alkali aqueous solution is added to the solution of a basic amino acid salt during the electrodialysis, whereby not only desalting is caused but also the counter anions of the basic amino acid are removed to such degree that the said counter anions remain in an amount of 40 mol % or smaller based on the basic amino acid, and also to a method for producing a basic amino acid solution which comprises subjecting a solution of a basic amino acid salt to electrodialysis with the use of an electrodialyser equipped with anion exchange membrane alone, wherein an alkali aqueous solution is added to the solution of a basic amino acid salt to adjust the pH of the solution to 7 to 10 during the electrodialysis, whereby the counter anions are removed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] [0018]FIG. 1 shows a schematic diagram for illustrating an example of an electrodialyser to be used in the practice of the method of the present invention.
DESCRIPTION OF SYMBOLS
[0019] [0019] 1 : ELECTRODIALYSER.
[0020] A 1 to A 10 ANION EXCHANGE MEMBRANES.
[0021] K 1 to K 12 : CATION EXCHANGE MEMBRANES.
[0022] [0022] 3 : ANODE
[0023] [0023] 4 : CATHODE
[0024] [0024] 5 to 15 : CONDUITS FOR SUPPLYING A SOLUTION TO BE DIALYZED.
[0025] [0025] 5 ′ to 15 ′: CONDUITS FOR DISCHARGING THE SOLUTION DIALYZED.
[0026] [0026] 16 to 27 : CONDUITS FOR SUPPLYING A DIALYSIS SOLVENT FOR COLLECTING THE COUNTER ANIONS DIALYZED.
[0027] [0027] 16 ′ to 27 ′: CONDUITS FOR DISCHARGING THE DIALYSIS SOLVENT WHICH HAS COLLECTED THE DIALYZED COUNTER ANIONS.
[0028] [0028] 28 to 30 : CONDUITS FOR SUPPLYING AN ELECTRODE SOLUTION.
[0029] [0029] 28 ′ to 30 ′: CONDUITS FOR DISCHARGING THE ELECTRODE SOLUTION.
DETAILED DESCRIPTION OF THE INVENTION
[0030] Hereinbelow, the present invention will be described in great detail.
[0031] The method of the present invention is carried out by using an electrodialyser equipped with sulfonic acid type or carboxylic acid type cation exchange membrane(s) and quaternary ammonium base type or tertiary amine type anion exchange membrane(s) in combination or an electrodialyser equipped with quaternary ammonium base type or tertiary amine type anion exchange membrane(s). The number of ion exchange membranes disposed in the electrodialyser, the capacity of the electrodialyser, the number of the isolated chambers for a solution to be dialyzed and for a dialysis solvent in the electrodialyser and the size of the isolated chambers can be selected by those skilled in the art in a given case so appropriately as to achieve the object of the present invention.
[0032] There may be mentioned as a specific example of an electrodialyser to be used according to the present invention an electrodialyser in which an anode chamber, a raw material solution chamber (a chamber for a solution to be dialyzed), a salt recovering solvent chamber (dialysis solvent chamber) and a cathode chamber are separated with anion exchange membrane(s) and a cation exchange membrane(s). In the electrodialyser, a 5% sodium sulfate solution or the like is circulated in the cathode and anode chambers. In the raw material solution chamber, a basic amino acid salt solution such as a lysine fermentation broth or the like is made to pass, and in the adjacent salt recovering solvent chamber, pure water or the like is made to pass initially.
[0033] A plurality of raw material solution chambers and salt recovering solvent chambers can be of course used. To be more specific, electrodialysis can be carried out with the use of an appratus shown in FIG. 1, for example. In FIG. 1, in an electrodialyser 1 , cation exchange membranes K 1 K 2 , K 3 , . . . , K 10 and anion exchange membranes A 1 , A 2 , A 3 , . . . , A 10 are disposed alternately, one cation exchange membrane after another anion exchange membrane and cation exchange membranes K 11 and K 12 are in turn disposed after the anion exchange membrane A 10 so as to constitute a plurality of isolated chambers 2 , 2 , . . . , 2 . In the electrodialyser, an anode 3 (anode chamber) and a cathode 4 (cathode chamber) are provided at the ends so as to oppose each other.
[0034] A sample solution (raw material solution, solution to be dialyzed) is supplied into the electrodialyser via a conduit 5 and branch pipes 6 , 7 , 8 , . . . , 15 , flows through raw material solution chambers between the anion exchange membranes and the cation exchange membranes, and is discharged from the electrodialyser via branch pipes 6 ′, 7 ′, 8 ′, . . . , 15 ′ and a conduit 5 ′. Further, a dialysis solvent such as pure water or the like for collecting the dialyzed counter anions is supplied into the electrodialyser via a conduit 16 and branch pipes 17 , 18 , 19 , . . . , 27 and discharged from the electrodialyser via branch pipes 17 ′, 18 ′, 19 ′, . . . , 27 ′ and a conduit 16 ′. Meanwhile, a solution of a salt such as sodium sulfate which is appropriate as an electrode is introduced into the electrodialyser via a conduit 28 and branch pipes 29 and 30 and discharged from the electrodialyser via branch pipes 29 ′ and 30 ′ and a conduit 28 ′. During this operation, a direct current is made to pass between the electrodes.
[0035] According to the above-described electrodialysis using cation exchange membranes and anion exchange membranes in combination, desalting is carried out in addition to removal of counter anions. The removal of counter anions can still be achieved with the sole use of anion exchange membranes, in addition to the above concurrent use of cation exchange membranes and anion exchange membranes.
[0036] When only anion exchange membranes are used, an electrodialyser obtained by replacing all the cation exchange membranes K 1 , K 2 , K 3 , . . . , K 10 of the electrodialyser shown in FIG. 1 with anion exchange membranes can be used, for example. As a dialysis solvent to be supplied into the electrodialyser via the conduit 16 and the branch pipes 17 , 18 , 19 , . . . , 27 and discharged from the electrodialyser via the branch pipes 17 ′, 18 ′, 19 ′, . . . , 27 ′ and the conduit 16 ′, an alkal aqueous solution can be used. A solution to be dialyzed is subjected to electrodialysis after an alkali aqueous solution is added to the solution to adjust the pH of the solution to 7 to 10 so as to remove counter anions.
[0037] As an inflow velocity of the sample solution, a membrane surface linear velocity of not lower than 1 cm/sec, preferably 4 to 6 cm/sec, can be used. Conditions for electrodialysis such as a current density, a voltage, a duration of electrodialysis, and the like can be selected appropriately, depending upon characteristics of a basic amino acid salt solution which is a solution to be dialyzed, coexisting salts, the types and numbers of cation exchange membranes and anion exchange membranes to be used, the size of an electrodialyser, and the like. In general, good results can be obtained at a current density of about 1 to 5 A/dm 2 . The temperature can be room temperature to 70° C.
[0038] When electrodialysis is carried out by concurrent use of cation exchange membranes and anion exchange membranes, counter anions are dialyzed via the anion exchange membranes and removed from the raw material solution chambers, while foreign cations are dialyzed via the cation exchange membranes and removed into the salt recovering chambers. In this case, in order to remove the counter anions of a basic amino acid with the basic amino acid being left in the raw material solution, the amount of cations to be removed into the salt recovering chambers gets relatively insufficient. Therefore, an alkali aqueous solution such as ammonia water or the like which contains cations which pass through the cation exchange membranes easily, is added to the raw material solution, whereby the counter anions of the basic amino acid can be removed into the salt recovering solvent without the target amino acid being lost into the salt recovering solvent.
[0039] Illustrative examples of anion exchange membranes and cation exchange membranes to be used according to the production method of the present invention include “CEMILEON AMV” and “CELEMION CMV” (products of Asahi Glass Company), and “ACIPLEX A-211” and “ACIPLEX A-201”, and “ACIPLEX K-101” (products of Asahi Kasei Corporation).
[0040] As ion exchange membranes to be used for electrodialysis according to present invention, ordinary ion exchange membranes as described above may be used. However, the fractional molecular weight of a cation exchange membrane is preferably smaller than the molecular weight of the basic amino acid from the viewpoint of prevention of outflow of the basic amino acid and, for example, a cation exchange membrane having a fractional molecular weight of about 100 is preferably used. On the other hand, when the fractional molecular weight of an anion exchange membrane is too small, efficiency of removal of counter anions is reduced. Therefore, a membrane having a fractional molecular weight slightly larger than the molecular weight of the main anions to be removed, is preferably used. E.g., when sulfate ions are to be removed, they can be removed efficiently with the use of a membrane having a fractional molecular weight of at least 300, for example.
[0041] An alkali aqueous solution to be added and used according the production method of the present invention is not particularly limited, and may be ammonia water or an aqueous solution of a hydroxide of an alkali metal such as sodium, potassium or the like, for example. However, when a desalted solution resulting from electrodialysis is to be concentrated, use of ammonia water makes it possible to remove ammonia into the drain. Therefore, in this case, use of ammonia is preferred. However, it is not limited thereto when the concentration is carried out by loose RO or the like.
[0042] The concentration of the alkali aqueous solution is not particularly limited, either. However, when the solution gets diluted, loads on concentration or the like in the subsequent step increase. To avoid this, the concentration of ammonia water should be 25 to 29%, and the concentration of an alkali aqueous solution containing cations of an alkali metal such as sodium or the like should be around 25 to 48%.
[0043] The amount of an alkali to be added and used is such an amount that is an equimolar amount of the anions to be removed or an amount corresponding to electric charges of the basic amino acid as required, in addition thereto. An excess amount of an alkali exceeding the amount is not necessary.
[0044] As an amino acid solution to be subjected to electrodialysis according to the present invention, a basic amino acid solution having a basic amino acid salt such as commercially available lysine hydrochloride or the like dissolved therein, can be used. In addition, an amino acid solution obtained by a synthesis method, a fermentation method, a proteolysis method or the like, as well as a crystallization mother liquor resulting from crystallization of crystals of lysine hydrochloride or the like, can also be used.
[0045] Further, in the basic amino acid salt solution to be subjected to electrodialysis, cations, proteins, organic acids or the like derived from a fermentation broth or a synthesis solution may be contained in such amounts that do not inhibit the efficiency of the electrodialysis.
[0046] Regarding addition of an alkali aqueous solution at the time of electrodialysis, it may be added to a basic amino acid salt solution to be subjected to electrodialysis in advance or may be added gradually during the electrodialysis process.
[0047] A basic amino acid solution produced by the production method of the present invention and having a reduced amount of counter ions can be concentrated to a high concentration because an amino acid is not easily deposited therefrom when concentrated. Although such a high-concentration amino acid solution can be used as it is as an amino acid solution, it can be highly purified by adding desired counter anions such as chloride ions or the like in the form of an free acid, whereby crystals of a basic amino acid salt are formed.
[0048] Further, utiligation of the present invention makes it possible to convert a basic amino acid solution having a variety of counter anions into an amino acid salt having a desired kind of counter anions.
[0049] A salt waste solvent (salt-recovered solvent) obtained by use of the present invention contains salts derived mainly from the counter anions. Therefore, the salts can be recovered from the salt waste solvent and recycled as raw materials for fermentation or the like.
EXAMPLES
[0050] The present invention will be described in detail with reference to examples hereinafter.
Example 1
Concurrent Use of Cation Exchange Membranes and Anion Exchange Membranes (Fermentation Broth)
[0051] Electrodialysis was carried out by use of 1.040 g of a lysine solution obtained by removing the microbial cells by means of an ultrafiltration membrane from a lysine fermentation broth obtained by culturing a microorganism having a lysine producing capability. The concentration of lysine in the solution to be subjected to electrodialysis was 9.7%, and the concentration of sulfate ions as the counter anions was 4.0%. In addition to these, 0.3% of organic acids and 0.25% of alkali metal ions such as potassium ions, sodium ions and the like were also contained therein. This solution was subjected to electrodialysis with the use of a “Micro Acilyzer G3” electrodialyser of Asahi Kasei corporation. The ion exchange membrane used in the electrodialysis was an “AC-120-400 type” membrane comprising cation exchange membranes and anion exchange membranes in combination. The fractional molecular weight of the cation exchange membranes was 100, and the fractional molecular weight of the anion exchange membranes was 300, the membrane areas of the cation and anion exchange membranes being both 400 cm 2 .
[0052] The electrodialysis was initiated by use of 300 g of pure water as the dialysis solvent as a salt recovering solvent. After 8 minutes from the initiation of the electrodialysis, addition of 28% ammonia water was started to the solution to be dialyzed at a rate of 0.8 g/min, and the electrodialysis was then continued until no reduction in conductivity was recognized. The average electric current and the average voltage during the electrodialysis were 1.4 A/dm 2 and 13.8 V, respectively. The time spent for the electrodialysis was 120 minutes, and the final pH of the solution dialyzed was 9.6.
[0053] When the amino acid solution after the electrodialysis was analyzed, 94% of the lysine had been recovered. At this point in time, 75% of the sulfate ions which were the counter anions had been removed, and the proportion thereof was reduced to 33 mol % based on the lysine. The removal ratio of the alkali metal ions such as potassium ions, sodium ions and the like was 90%, and the removal ratio of the ammonium ions including the added portion was 80%. The removal ratio of the organic acids was 45%, and the amount of the lysine in the solid content of the solution was increased to 85% from 65% as compared with that before the electrodialysis (increase in purity). This solution was concentrated by removing the ammonia therefrom, whereby a high-concentration lysine solution having a concentration of 51% could be prepared at room temperature without observing deposition of lysine crystals.
Example 2
Concurrent Use of Cation Exchange Membranes and Anion Exchange Membranes (Fermentation Broth)
[0054] Electrodialysis was carried out by use of 998 g of a lysine solution obtained by removing the microbial cells by means of an ultrafiltration membrane from a lysine fermentation broth obtained by culturing a microorganism having a lysine producing capability. The concentration of lysine in the solution to be subjected to electrodialysis was 12%, the concentration of sulfate ions as the counter anions was 1.3%, and the concentration of chloride ions (chlorine ions) was 2.4%. In addition to these, 0.3% of alkali metal ions such as potassium ions, sodium ions and the like was also contained therein. This solution was subjected to electrodialysis with the use of a “Micro Acilyzer G3” electrodialyser of Asahi Kasei Corporation. The ion exchange membrane used in the electrodialysis was an “AC-120-400 type” membrane comprising cation exchange membranes and anion exchange membranes in combination. The fractional molecular weight of the cation exchange membranes was 100, and the fractional molecular weight of the anion exchange membranes was 300, the membrane areas of the cation and anion exchange membranes being both 400 cm 2 .
[0055] The electrodialysis was initiated by use of 300 g of pure water as the dialysis solvent as a salt recovering solvent. After 5 minutes from the initiation of the electrodialysis, addition of 28% ammonia water was started to the solution to be dialyzed at a rate of 0.72 g/min, and the electrodialysis was then continued until no reduction in conductivity was recognized. The time spent for the electrodialysis was 100 minutes, and the final pH of the solution dialyzed was 9.3.
[0056] When the amino acid solution after the electrodialysis was analyzed, 94% of the lysine had been recovered. At this point in time, 97% of the chloride ions had been removed, 80% of the sulfate ions had been removed, and the remaining counter anions had been reduced to 29 mol % based on the lysine. The removal ratio of the alkali metal ions such as potassium ions, sodium ions and the like was 90%, and the amount of the lysine in the solid content of the solution was increased to 82% from 65% as compared with that before the electrodialysis (increase in purity). This solution was concentrated by removing the ammonia therefrom, whereby a high-concentration lysine solution having a concentration of 49% could be prepared at room temperature without observing deposition of lysine crystals.
Example 3
Concurrent Use of Cation Exchange Membranes and Anion Exchange Membranes (Crystallization Mother Liquor)
[0057] Electrodialysis was carried out by use of a solution obtained by adding 300 g of pure water to 470 g of a crystallization mother liquor resulting from removal of the lysine hydrochloride crystals from a lysine solution obtained by removing the microbial cells by means of an ultrafiltration membrane from a lysine fermentation broth obtained by culturing a microorganism having a lysine producing capability. The concentration of lysine in the solution to be subjected to electrodialysis was 10.9%, the concentration of chloride ions was 4.25%, the concentration of sulfate ions was 5.7%, the concentration of sodium ions was 0.6%, the concentration of potassium ions was 0.55%, the concentration of ammonium ions was 1.9%, and the concentration of organic acids was 1.3%. The proportion of lysine in the solid content of this solution was 34%. This solution was subjected to electrodialysis by use of a “Micro Acilyzer G3” electrodialyser of Asahi Kasei Corporation. The ion exchange membrane used in the electrodialysis was an “AC-120-400 type” membrane, the fractional molecular weight of the cation exchange membranes was 100, and the fractional molecular weight of the anion exchange membranes was 300, the membrane areas of the cation and anion exchange membranes being both 400 cm 2 .
[0058] The electrodialysis was initiated by use of 300 g of pure water as the dialysis solvent as a salt recovering solvent. After 70 minutes from the initiation of the electrodialysis where the voltage which had been once decreased began to be increased again, addition of 28% ammonia water was started to the solution to be dialyzed at a rate of 0.64 g/min, and the electrodialysis was continued until no reduction in conductivity was recognized after the electric current was decreased. The time spent for the electrodialysis was 150 minutes, and the final pH of the solution dialyzed was 9.4. The average electric current and the average voltage during the electrodialysis were 2 A/dm 2 and 12.2 V, respectively.
[0059] When the amino acid solution after the electrodialysis was analyzed, 94.5% of the lysine had been recovered. At this point in time, 96% of the chloride ions had been removed, 90% of the sulfate ions had been removed, and the proportion of the remaining counter anions was reduced to 21 mol % based on the lysine. The removal ratio of the alkali metal ions such as potassium ions, sodium ions and the like was 96%, and the removal ratio of the ammonium ions including the added portion was 85%. The removal ratio of the organic acids was 57% on the average, and the amount of the lysine in the solid content of the solution was increased to 53% from 34% as compared with that before the electrodialysis (increase in purity). This solution was concentrated by removing the ammonia therefrom, whereby a high-concentration lysine solution having a concentration of 32% could be prepared without observing deposition of lysine crystals, though it was increased in viscosity to 2.4 Pa·s(10° C.), said concentration of 32% being about three times 10.9% which was, in turn, the lysine concentration of the crystallization mother liquor before the electrodialysis.
Example 4
Concurrent Use of Cation Exchange Membranes and Anion Exchange Membranes (Crystallization Mother Liquor)
[0060] Electrodialysis was carried out by use of a solution obtained by adding 300 g of pure water to 467 g of a crystallization mother liquor resulting from removal of the lysine hydrochloride crystals from a lysine solution obtained by removing the microbial cells by means of an ultrafiltration membrane from a lysine fermentation broth obtained by culturing a microorganism having a lysine producing capability. The concentration of lysine in the solution to be subjected to electrodialysis was 10.8%, the concentration of chloride ions was 4.05%, the concentration of sulfate ions was 5.3%, the concentration of sodium ions was 0.5%, the concentration of potassium ions was 0.5%, the concentration of ammonium ions was 1.8%, and the concentration of organic acids was 1.3%. The proportion of lysine in the solid content of this solution was 34%. This solution was subjected to electrodialysis by use of a “Micro Acilyzer G3” electrodialyser of Asahi Kasei Corporation. The ion exchange membrane used in the electrodialysis was an “AC-130-400 type” membrane, the fractional molecular weight of the cation exchange membranes was 100, and the fractional molecular weight of the anion exchange membranes was 300, the membrane areas of the cation and anion exchange membranes being both 400 cm 2 .
[0061] The electrodialysis was initiated by use of 300 g of pure water as the dialysis solvent as a salt recovering solvent. After 80 minutes from the initiation of the electrodialysis where the voltage which had been once decreased began to be increased again, addition of 28% ammonia water was started to the solution to be dialyzed at a rate of 0.61 g/min, and the electrodialysis was continued until no reduction in conductivity was recognized after the electric current was decreased. The time spent for the electrodialysis was 180 minutes, and the final pH of the solution dialyzed was 9.6. The average electric current and the average voltage during the electrodialysis were 1.9 A/dm 2 and 11.2 V, respectively.
[0062] When the amino acid solution after the electrodialysis was analyzed, 90% of the lysine had been recovered. At this point in time, 95% of the chloride ions had been removed, 80% of the sulfate ions had been removed, and the proportion of the remaining counter anions was reduced to 39 mol % based on the lysine. The removal ratio of the alkali metal ions such as potassium ions, sodium ions and the like was 96%, and the removal ratio of the ammonium ions including the added portion was 85%. The removal ratio of the organic acids was 67% on the average, and the amount of the lysine in the solid content of the solution was increased to 50% from 34% as compared with that before the electrodialysis (increase in purity). This solution was concentrated by removing the ammonia therefrom, whereby a high-concentration lysine solution having a concentration of 31% could be prepared without observing deposition of lysine crystals, said concentration of 31% being about three times 10.8% which was, in turn, the lysine concentration of the crystallization mother liquor before the electrodialysis.
Example 5
Concurrent Use of Cation Exchange Membranes and Anion Exchange Membranes (Crystallization Mother Liquor)
[0063] Electrodialysis was carried out by use of a solution obtained by adding 300 g of pure water to 470 g of a crystallization mother liquor resulting from removal of the lysine hydrochloride crystals from a lysine solution obtained by removing the microbial cells by means of an ultrafiltration membrane from a lysine fermentation broth obtained by culturing a microorganism having a lysine producing capability. The concentration of lysine in the solution to be subjected to electrodialysis was 9.9%, the concentration of chloride ions was 4.1%, the concentration of sulfate ions was 5.7%, the concentration of sodium ions was 0.6%, the concentration of potassium ions was 0.56%, the concentration of ammonium ions was 1.8%, and the concentration of organic acids was 1.3%. The proportion of lysine in the solid content of this solution was 34%. This solution was subjected to electrodialysis by use of a “Micro Acilyzer G3” electrodialyser of Asahi Kasei Corporation. The ion exchange membrane used in the electrodialysis was an “AC-120-400 type” membrane, the fractional molecular weight of the cation exchange membranes was 100, and the fractional molecular weight of the anion exchange membranes was 300, the membrane areas of the cation and anion exchange membranes being both 400 cm 2 .
[0064] The electrodialysis was initiated by use of 300 g of pure water as the dialysis solvent as a salt recovering solvent. After 84 minutes from the initiation of the electrodialysis where the voltage which had been once decreased began to be increased again, addition of 28% ammonia water was carried out in an amount of 99.6 g until the pH of the solution to be dialyzed got to the isoelectyric point of lysine, and the electrodialysis was continued until no reduction in conductivity was recognized after the electric current was decreased. The time spent for the electrodialysis was 208 minutes.
[0065] When the amino acid solution after the electrodialysis was analyzed, 75% of the lysine had been recovered. At this point in time, 98% of the chloride ions had been removed, 94% of the sulfate ions had been removed, and the proportion of the remaining counter anions was reduced to 19 mol % based on the lysine. The removal ratio of the alkali metal ions such as potassium ions, sodium ions and the like was 95%, and the removal ratio of the ammonium ions including the added portion was 93%. The removal ratio of the organic acids was 67% on the average, and the amount of the lysine in the solid content of the solution was increased to 50% from 34% as compared with that before the electrodialysis (increase in purity). This solution was concentrated by removing the ammonia therefrom, whereby a high-concentration lysine solution having a concentration of 30% could be prepared without observing deposition of lysine crystals, said concentration of 30% being about three times 9.9% which was, in turn, the lysine concentration of the crystallization mother liquor before the electrodialysis.
Example 6
Sole Use of Anion Exchange Membranes
[0066] Electrodialysis was carried out by use of 8,560 g of a lysine solution obtained by removing the microbial cells by means of an ultrafiltration membrane from a lysine fermentation broth obtained by culturing a microorganism having a lysine producing capability. The concentration of lysine in a solution to be subjected to electrodialysis was 10.0%, the concentration of sulfate ions as the counter anions was 3.8%, the concentration of organic acids was 0.3%, and the concentration of alkali metal ions such as potassium ions, sodium ions and the like was 0.25%. As an electrodialyser, a commercially available experimental electrodialyser “CELEMION ELECTODIALYSER DU-06” of Asahi Kasei Corporation was used. Twenty sheets of commercially available anion exchange membrane “CELEMION AMV” of Asahi Glass Corporation were installed in the electrodialyser with an effective area of 209 cm 2 /sheet at an interval between the sheets of 2 mm. An alkali solution was passed through the anode chamber, a lysine solution which was a solution to be dialyzed was passed through a chamber adjacent to the anode chamber, and an alkali aqueous solution as the dialysis solvent was passed through a chamber adjacent to the chamber through which the lysine solution was passed, and so on, whereby the lysine solution to be dialyzed and the alkali aqueous solution as the dialysis solvent were passed alternately, through next chamber to each other, and concurrently. In the last cathode chamber, a sodium hydroxide aqueous solution was circulated in such a manner that it was isolated from other alkali aqueous solutions.
[0067] The electrodialysis was continued by passing a current of 1 A/dm 2 through the electrodialyser while a solution obtained by adjusting the pH of the lysine solution which was a solution to be dialyzed to a pH of 8.5 by use of ammonia solution was circulated at a rate of 35 L/hr on the average. As a result, it took 4 hours and 30 minutes to complete removal of the anions.
[0068] When the amino acid solution after the electrodialysis was analyzed, 96% of the lysine had been recovered. At this point in time, 72% of the sulfate ions which were the counter anions had been removed, and the proportion thereof was reduced to 33 mol % based on the lysine. The amount of the lysine in the solid content of the solution was increased to 83% from 65% as compared with that before the electrodialysis (increase in purity). This solution was concentrated by removing the ammonia therefrom, whereby a high-concentration lysine solution having a concentration of 48% could be prepared at room temperature without observing deposition of lysine crystals.
Comparative Example 1
Non-Addition of Alkali Aqueous Solution
[0069] Electrodialysis was carried out by use of a solution obtained by adding 300 g of pure water to 474 g of a crystallization mother liquor resulting from removal of the lysine hydrochloride crystals from a lysine solution obtained by removing the microbial cells by means of an ultrafiltration membrane from a lysine fermentation broth obtained by culturing a microorganism having a lysine producing capability. The concentration of lysine in the solution to be subjected to electrodialysis was 10.8%, the concentration of chloride ions was 3.9%, the concentration of sulfate ions was 4.9%, the concentration of sodium ions was 0.41%, the concentration of potassium ions was 0.39%, the concentration of ammonium ions was 1.8%, and the concentration of organic acids was 1.0%. The proportion of lysine in the solid content of this solution was 34%. This solution was subjected to electrodialysis by use of a “Micro Acilyzer G3” electrodialyser of Asahi Kasei Corporation. The ion exchange membrane used in the electrodialysis was an “AC-120-400 type” membrane, the fractional molecular weight of the cation exchange membranes was 100, and the fractional molecular weight of the anion exchange membranes was 300, the membrane areas of the cation and anion exchange membranes being both 400 cm 2 .
[0070] The electrodialysis was initiated by use of 300 g of pure water as the dialysis solvent as a salt recovering solvent. After the initiation of the electrodialysis, the voltage was once decreased and increased again, and the electric current began to be decreased. The electrodialysis was continued until no reduction in conductivity was recognized after the electric current was decreased enough. The time spent for the electrodialysis was 150 minutes, and the pH of the solution dialyzed was 5.9.
[0071] When the amino acid solution after the electrodialysis was analyzed, 92% of the lysine had been recovered, and 92% of the chloride ions had been removed. Hoever, only 50% of the sulfate ions had been removed, and the proportion of the remaining counter anions was 130 mol % based on the lysine.
[0072] It can be understood from the above that although removal of excess salts might be achieved by mere electrodialysis, it fails to remove the counter anions of lysine. Further, the amount of lysine in the solid content of the solution was increased to at most 45% from 34%, and an increase in purity was small as compared with Example 3.
[0073] [Effect of the Invention]
[0074] As described above, according to the present invention, the counter anions as well as excess salts can be removed from a solution of the salt of a basic amino acid such as lysine or the like, by adding an alkali aqueous solution such as ammonia water or the like to the solution when subjected to electrodialysis. Thereby, a high-concentration amino acid solution can be produced, and costs in transportation and preservation of a basic amino acid can be reduced. Further, when a basic amino acid solution is subjected to spray granulation or the like, a solution having a high concentration can be subjected to spraying. In addition, since counter anions can be removed from a fermentation broth or the like of a basic amino acid salt or the like according to the present invention, crystals of an amino acid salt having the target counter anions can be produced by adding the desired anions to the solution again.
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Herein are disclosed a method for producing a basic amino acid solution which comprises subjecting a solution of a basic amino acid salt to electrodialysis with the use of an electrodialyser equipped with cation exchange membranes and anion exchange membranes in combination, wherein an alkali aqueous solution is added to the solution of a basic amino acid salt during the electrodialysis, whereby not only desalting is caused but also the counter anions of the basic amino acid are removed to such degree that the said counter anions remain in an amount of 40 mol % or smaller based on the basic amino acid, as well as a method for producing a basic amino acid solution which comprises subjecting a solution of a basic amino acid salt to electrodialysis with the use of an electrodialyser equipped with anion exchange membrane alone, wherein an alkali aqueous solution is added to the solution of a basic amino acid salt to adjust the pH of the solution to 7 to 10 during the electrodialysis, whereby the counter anions are removed.
According to these methods, a basic amino acid solution having a high concentration within the concentration range in which crystals of a basic amino acid salt are not deposited, can be easily provided, by removing the counter anions from a solution of a basic amino acid salt efficiently by use of electrodialysis.
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BACKGROUND OF THE INVENTION
The invention relates to a stabilized, pulverulent red phosphorus material composed of phosphorus particles whose particle size is not more than 2 mm, and whose surface has been covered with a thin layer of an oxidation stabilizer, and also to the use of the same, and to a process for its preparation.
It is known that heat can be used to obtain red phosphorus by converting yellow phosphorus into the more stable red form. The resultant crude red phosphorus has a content of from about 0.5 to 1.5% by weight of yellow phosphorus at the end of the reaction, and forms a compact mass. It is ground in an atmosphere of inert gas and freed from yellow phosphorus by boiling an aqueous suspension with dilute sodium hydroxide solution. Rotating reactors are usually used for the conversion process, and the product is pulverulent red phosphorus.
The aqueous suspension of red phosphorus removed from the reactor is heated in stirred vessels with steam and freed from the residual content of about 0.1% by weight of yellow phosphorus by gradually adding sodium hydroxide solution.
Red phosphorus is used in pyrotechnic applications and in producing match-striking surfaces, and as a flame retardant for plastics, e.g. polyamides and polyurethanes.
It is known that a chemical reaction takes place on the surface of red phosphorus in a humid atmosphere, forming phosphine (PH 3 ) and various phosphorus-containing acids in oxidation states from +1 to +5 via oxidation and disproportionation.
Phosphine is a toxic gas whose MAC is 0.1 ppm. Low concentrations can be detected by a garlic-like odor (the odor threshold being 0.02 ppm). The various phosphorus-containing acids cause corrosion problems in pyrotechnic and flame-retardant applications, especially corrosion of copper.
An object was therefore to improve the unsatisfactory oxidation resistance of red phosphorus by taking appropriate stabilization measures. For the purposes of the invention, the term “stabilization” here implies a measure which gives the red phosphorus improved protection from the results of exposure to the atmosphere, therefore contributing, for example, to reduced formation of phosphorus oxoacids and phosphine during storage and further processing.
EP-0 378 803 B1 (DE-C 39 00 965) discloses that the oxidation resistance of red phosphorus can be improved by tin oxide hydrate precipitation.
EP-0 028 744 B1 (DE-C 29 45 118) proposes using a combination of aluminum hydroxide and cured epoxy resin to stabilize red phosphorus.
EP-0 283 759 B1 (U.S. Pat. No. 4,853,288) describes a stabilized pulverulent red phosphorus composed of phosphorus particles whose particle size is no more than 2 mm and whose surface has been covered with a thin layer of an oxidation stabilizer which is composed of at least one metal hydroxide with little or no solubility in water and of a polycondensation product made from melamine and formaldehyde. The oxidation resistance values obtained from the combinations of tin oxide hydrate and melamine-formaldehyde resin described in Examples 17 and 18 of that specification are certainly good.
However, there continues to be a requirement for red phosphorus products with improved oxidation resistance, since, depending on the temperature and the humidity of the ambient air, there is a possibility of exceeding the odor threshold for phosphine, particularly during processing.
An attempt to bind phosphine is described in DE-A 2 308 104. This specification describes molding compositions made from thermoplastics with red phosphorus and with addition of a phosphine-binding substance. Phosphine-binding substances mentioned are MoS 2 , PbO 2 , AgNO 3 , HgCl 2 , FeCl 3 , CuO, and activated carbon. The red phosphorus here is mixed with the phosphine-binding substance and incorporated into the polymer concerned. The disadvantage of this process is the need to add a further additive in the form of the phosphine-binding substance: in some cases the water-solubility of the compounds mentioned is high, polymer compatibility is unsatisfactory, and thermal stability is low.
SUMMARY OF THE INVENTION
An object was therefore to make a further improvement in oxidation resistance. Surprisingly, it has now been found that the oxidation resistance of red phosphorus can be markedly improved by applying metallic silver, in particular in combination with a metal hydroxide and with a fully cured synthetic thermoset resin.
The effect of the invention may, where appropriate, be further amplified by also applying a phlegmatizer by the process of EP-0 176 836 B1 (DE-A 34 36 161).
The term “phlegmatization” here implies a measure which reduces the tendency of red phosphorus to form dust, thus reducing the risk that a dust explosion may occur, and increasing process safety.
DETAILED DESCRIPTION OF THE INVENTION
The invention therefore provides a stabilized pulverulent red phosphorus material of the type mentioned at the outset, wherein the oxidation stabilizer is silver.
The stabilized, pulverulent red phosphorus material preferably comprises from 0.05 to 2% by weight of silver, particularly preferably from 0.1 to 0.4% by weight of silver.
The stabilized, pulverulent red phosphorus material preferably comprises an additional stabilizer.
The additional stabilizer is preferably a metal hydroxide.
The starting materials preferably used for the metal hydroxide are the hydroxides, oxide hydrates and/or oxides of aluminum, silicon, titanium, chromium, manganese, zinc, germanium, zirconium, niobium, cadmium, tin, lead, bismuth and/or cerium.
The red phosphorus material preferably comprises from 0.5 to 10% by weight, particularly preferably from 1 to 3% by weight, of the metal hydroxides.
The stabilized, pulverulent red phosphorus material has preferably been microencapsulated by a synthetic thermoset resin.
The synthetic thermoset resin is preferably an epoxy resin, a melamine resin, a phenolic resin, or a polyurethane.
The stabilized, pulverulent red phosphorus material preferably comprises from 0.2 to 10% by weight, in particular from 0.5 to 8% by weight, and particularly preferably from 2 to 5% by weight, of the thermoset plastics.
The stabilized, pulverulent red phosphorus material has preferably been covered by a thin layer of a phlegmatizer.
The phlegmatizer is preferably a water-emulsifiable organic compound.
The phlegmatizer is preferably di-2-ethylhexyl phthalate or polyglycols.
The stabilized, pulverulent red phosphorus material preferably comprises from 0.05 to 2% by weight, particularly preferably from 0.3 to 1.5% by weight, of the phlegmatizer.
The invention particularly provides a stabilized, pulverulent red phosphorus material which comprises from 76 to 99.2% by weight of red phosphorus, from 0.05 to 2% by weight of silver, from 0.5 to 10% by weight of metal hydroxide, from 0.2 to 10% by weight of synthetic thermoset resin, and from 0.05 to 2% by weight of phlegmatizer.
The invention also provides a process for preparing a stabilized, pulverulent red phosphorus material, which comprises in succession,
stirring a water-soluble silver compound into an aqueous suspension of the (untreated) red phosphorus and adjusting the pH to 7;
stirring a water-soluble metal compound into this suspension and adjusting the pH to a value of from 4 to 9, and continuing to stir at from 40 to 80° C. for from 0.5 to 3 hours;
then adding an aqueous emulsion comprising an epoxy resin and comprising an epoxy resin hardener and continuing to stir at from 40 to 80° C. for from 0.5 to 3 hours; adding an aqueous emulsion of the water-emulsifiable organic compound serving as phlegmatizer and adjusting the pH to a value of from 5 to 9, and continuing to stir at from 20 to 90° C. for from 0.5 to 3 hours and then filtering the product and drying the same at temperatures from 80 to 150° C.
In one particular embodiment of the invention, the emulsion obtained after step a) is filtered and the resultant silver-containing red phosphorus material is dried at temperatures of from 80 to 150° C.
In another embodiment of the invention, only steps a) and b) are carried out, and the resultant silver-containing red phosphorus material stabilized by a metal hydroxide is dried at temperatures of from 80 to 150° C.
In another embodiment of the invention, steps a) to c) are carried out, and the resultant silver-containing red phosphorus material stabilized by a metal hydroxide and by a synthetic thermoset resin is dried at temperatures of from 80 to 150° C.
An alternative is to carry out only steps a), b), and d), and use temperatures of from 80 to 150° C. to dry the resultant silver-containing phosphorus material stabilized by a metal hydroxide and provided with a phlegmatizer.
The invention also provides a process for preparing a stabilized, pulverulent red phosphorus material, wherein the materials used in each instance comprise, as desired, from 76 to 99.2% by weight of red phosphorus, from 0.05 to 2% by weight of water-soluble silver compound, from 0.5 to 10% by weight of metal hydroxide, metal oxide hydrate, or metal oxide from 0.2 to 10% by weight of synthetic thermoset resin, and from 0.05 to 2% by weight of phlegmatizer.
Finally, the invention provides the use of the stabilized, pulverulent red phosphorus material as flame retardant or for preparing flame retardants.
An example of a method for carrying out the process for preparing the stabilized, pulverulent red phosphorus material consists in stirring a water-soluble silver compound into an aqueous suspension of red phosphorus and adjusting the pH to 7, then stirring in a water-soluble tin compound, adjusting the pH value to from 4 to 9, and continuing to stir at a temperature of from 40 to 80° C. for from 0.5 to 3 hours, then adding an aqueous emulsion of the epoxy resin and the hardener and continuing to stir at a temperature of from 40 to 80° C. for from 0.5 to 3 hours, using from 76 to 99.2% by weight of red phosphorus, 0.05 to 2% by weight of silver, from 10 to 0.5% by weight of tin oxide hydrate, based on SnO, and from less than 10 to 0.2% by weight of epoxy resin or melamine resin, and finally filtering off the phosphorus particles and drying these at an elevated temperature.
Another method of carrying out the process is to prepare stabilized and phlegmatized pulverulent red phosphorus material by stirring a water-soluble silver compound into an aqueous suspension of red phosphorus and then stirring in a water-soluble tin compound, adjusting the pH value to from 4 to 9, continuing stirring at a temperature of from 40 to 80° C. for from 0.5 to 3 hours, then adding an aqueous emulsion of the epoxy resin or a solution of the epoxy resin in a water-miscible solvent, stirring at a temperature of from 40 to 80° C. for from 0.5 to 3 hours, and then, where appropriate, adding an aqueous emulsion of di-2-ethylhexyl phthalate and stirring at a temperature of from 20 to 90° C. for from 0.5 to 3 hours, using from 76 to 99.2% by weight of red phosphorus, from 0.05 to 2% by weight of silver, from 10 to 0.5% by weight of tin oxide hydrate, based on SnO, from 10 to 0.2% by weight of epoxy resin, and from 2 to 0.05% by weight of di-2-ethylhexyl phthalate, and finally filtering off the phosphorus particles and drying the same at an elevated temperature. The final drying of the phosphorus particles filtered off may preferably take place at a temperature of from 80 to 120° in a stream of nitrogen.
The final drying of the phosphorus particles filtered off may preferably take place at a temperature of from 80 to 120° C. in a stream of nitrogen.
The water-miscible solvent used is preferably acetone, methanol or ethanol.
EXAMPLES
An example of the preferred particle size of the pulverulent red phosphorus material is in the range from 0.1 to 500 μm, particularly preferably from 0.1 to 150 μm.
The tables and examples below give further illustration of the invention. Percentage data are in % by weight.
Determination of Oxidation Resistance
Oxidation resistance was determined by an aging test under hot and humid conditions. For this, 5.0 g of red phosphorus (particle size: 100%<150 μm) was weighed into a crystallization dish of diameter 50 mm and the dish was stored in a closed glass vessel at 80° C. and 100% relative humidity. The phosphine formed during this process was either flushed out of the glass vessel by a stream of air (10 l/h) and reacted with 2.5% strength mercury(II) chloride solution in a gas-scrubber bottle, using titration to determine the amount of hydrochloric acid produced, or was collected using a “phosphine 0.1/a” or “50/a” Drager tube.
To determine the content of the various phosphorus oxoacids, the phosphorus specimen was transferred to a 250 ml glass beaker, treated with 200 ml of 1% strength hydrochloric acid, heated at boiling point for 10 minutes, and then filtered. The molybdatovanadatophosphoric acid method was then used to determine acid-soluble phosphorus photometrically in the filtrate.
To determine the initial value for acid-soluble phosphorus, the red phosphorus was subjected to the same analysis procedure without any prior aging under hot and humid conditions. The value determined is then subtracted from the value obtained when determining the content of acid-soluble phosphorus after aging under hot and humid conditions.
Materials Used
Epoxy resin: Beckopox EP 140, bisphenol-A bisglycidyl ester, EP value 0.54 mol/100 g, polyamine hardener EH 623w, water-dilutable amine hardener from Vianova Resins GmbH, Mainz, Germany.
Melamine resin: Madurit MW 909, partially etherified melamine-formaldehyde resin, water-soluble powder, Vianova Resins GmbH, Mainz, Germany.
Example 1
Inventive
2000 ml of an aqueous red phosphorus suspension comprising 1000 g of red phosphorus are heated to 60° C. in a stirred glass reactor. The pH value of the suspension is adjusted to 7. A solution of 1.6 g of silver nitrate in 20 ml of water is then stirred in, and the pH value is maintained at 7. The mixture is then stirred at 60° C. for an hour at pH 7. After filtration the filter cake is washed with water and dried at 120° C. in a stream of nitrogen. The phosphorus content is 99.8%.
Example 2
Inventive
2000 ml of an aqueous red phosphorus suspension comprising 1000 g of red phosphorus are heated to 60° C. in a stirred glass reactor. The pH value of the suspension is adjusted to 7. A solution of 3.2 g of silver nitrate in 20 ml of water is then stirred in, and the pH value is maintained at 7. The mixture is then stirred at 60° C. for an hour at pH 7. After filtration the filter cake is washed with water and dried at 120° C. in a stream of nitrogen. The phosphorus content is 99.6%.
Example 3
Inventive
2000 ml of an aqueous red phosphorus suspension comprising 1000 g of red phosphorus are heated to 60° C. in a stirred glass reactor. The pH value of the suspension is adjusted to 7. A solution of 4.8 g of silver nitrate in 20 ml of water is then stirred in, and the pH value is maintained at 7. The mixture is then stirred at 60° C. for an hour at pH 7. After filtration the filter cake is washed with water and dried at 120° C. in a stream of nitrogen. The phosphorus content is 99.4%.
Example 4
Inventive
2000 ml of an aqueous red phosphorus suspension comprising 1000 g of red phosphorus are heated to 60° C. in a stirred glass reactor. The pH value of the suspension is adjusted to 7. A solution of 3.2 g of silver nitrate in 20 ml of water is then stirred in, and the pH value is maintained at 7. The mixture is then stirred at 60° C. for an hour at pH 7. The pH value is adjusted to 5 by adding 5% strength sulfuric acid. This is followed by addition of 48 g of SnSO 4 in 200 ml of water and stirring at 60° C. for 20 min. After filtration the filter cake is washed with water and dried at 120° C. in a stream of nitrogen. The phosphorus content is 97.8%.
Example 5
Inventive
2000 ml of an aqueous red phosphorus suspension comprising 1000 g of red phosphorus are heated to 60° C. in a stirred glass reactor. The pH value of the suspension is adjusted to 7. A solution of 3.2 g of silver nitrate in 20 ml of water is then stirred in, and the pH value is maintained at 7. The mixture is then stirred at 60° C. for an hour at pH 7. The pH value is adjusted to 3 by adding 5% strength sulfuric acid. This is followed by addition of 99.2 g of MgSO 4 *H 2 O in 200 ml of water, the pH value is adjusted to 12, and stirring at 60° C. for 20 min. After filtration the filter cake is washed with water and dried at 120° C. in a stream of nitrogen. The phosphorus content is 97.8%.
Example 6
Inventive
2000 ml of an aqueous red phosphorus suspension comprising 1000 g of red phosphorus are heated to 60° C. in a stirred glass reactor. The pH value of the suspension is adjusted to 7. A solution of 3.2 g of silver nitrate in 20 ml of water is then stirred in, and the pH value is maintained at 7. The mixture is then stirred at 60° C. for an hour at pH 7. The pH value is adjusted to 3 by adding 5% strength sulfuric acid. This is followed by addition 246 g Al 2 (SO 4 ) 3 *18 H 2 O in 200 ml of water, the pH value is adjusted to 7, and stirring at 60° C. for 20 min. After filtration the filter cake is washed with water and dried at 120° C. in a stream of nitrogen. The phosphorus content is 97.8%.
Example 7
Inventive
2000 ml of an aqueous red phosphorus suspension comprising 1000 g of red phosphorus are heated to 60° C. in a stirred glass reactor. The pH value of the suspension is adjusted to 7. A solution of 3.2 g of silver nitrate in 20 ml of water is then stirred in, and the pH value is maintained at 7. The mixture is then stirred at 60° C. for an hour at pH 7. The pH value is adjusted to 5 by adding 5% strength sulfuric acid. This is followed by addition of 48 g of SnSO 4 in 200 ml of water and stirring at 60° C. for 20 min. An aqueous emulsion comprising a water-emulsifiable epoxy resin and comprising a water-emulsifiable polyamine hardener (20 g of Beckopox EP 122w and 20 g of Beckopox EH 623w) is then stirred in and the mixture is stirred at about 60° C. for an hour, after which a further 20 g of Beckopox EP 122w and 20 g of Beckopox EH 623w are emulsified in water and added, and this is followed by stirring at 60° C. for about 1 h. The product is filtered off. After filtration the filter cake is washed with water and dried at 120° C. in a stream of nitrogen. The phosphorus content is 91.0%.
Example 8
Inventive
2000 ml of an aqueous red phosphorus suspension comprising 1000 g of red phosphorus are heated to 60° C. in a stirred glass reactor. The pH value of the suspension is adjusted to 7. A solution of 3.2 g of silver nitrate in 20 ml of water is then stirred in, and the pH value is maintained at 7. The mixture is then stirred at 60° C. for an hour at pH 7. The pH value is adjusted to 5 by adding 5% strength sulfuric acid. This is followed by addition of 48 g of SnSO 4 in 200 ml of water and stirring at 60° C. for 20 min. An aqueous solution of a melamine resin (40 g of Madurit MW 909) is then stirred in and the pH value is adjusted to 4.5 using dilute sulfuric acid. After an hour of stirring at 60° C., a further 40 g of Madurit MW 909 in solution in about 100 ml of water are added. After an hour of stirring at pH 4.5 at 60° C., the product is filtered off. After filtration the filter cake is washed with water and dried at 120° C. in a stream of nitrogen. The phosphorus content is 89.8%.
Example 9
Comparative Example
2000 ml of an aqueous red phosphorus suspension comprising 1000 g of red phosphorus are heated to 60° C. in a stirred glass reactor. The pH value is adjusted to 5 by adding 5% strength sulfuric acid. This is followed by addition of 48 g of SnSO 4 in 200 ml of water and stirring at 60° C. for 20 min. The product is then filtered off. After filtration the filter cake is washed with water and dried at 120° C. in a stream of nitrogen. The phosphorus content is 97.5%.
Example 10
Comparative Example
2000 ml of an aqueous suspension of red phosphorus comprising 1000 g of red phosphorus are heated to 60° C. in a stirred glass reactor. The pH value is adjusted to 5 by adding 5% strength sulfuric acid. An aqueous solution of a melamine resin (40 g of Madurit MW 909) is then stirred in and the pH is adjusted to 4.5 using dilute sulfuric acid. After one hour of stirring at 60° C. a further 40 g of Madurit MW 909 dissolved in about 100 ml of water are added. After an hour of stirring at pH 4.5 and 60° C. the product is filtered off. After filtering, the filter cake is washed with water and dried at 120° C. in a stream of nitrogen. The phosphorus content is 91.8%.
Example 11
Comparative Example
2000 ml of an aqueous suspension of red phosphorus comprising 1000 g of red phosphorus are heated to 60° C. in a stirred glass reactor. The pH value is adjusted to 5 by adding 5% strength sulfuric acid. 48 g of SnSO 4 in 200 ml of water are then added, and the mixture is stirred at 60° C. for 20 min. An aqueous solution of a melamine resin (40 g of Madurit MW 909) is then stirred in and the pH is adjusted to 4.5 using dilute sulfuric acid. After one hour of stirring at 60° C. a further 40 g of Madurit MW 909 dissolved in about 100 ml of water are added. After an hour of stirring at pH 4.5 and 60° C. the product is filtered off. After filtering, the filter cake is washed with water and dried at 120° C. in a stream of nitrogen. The phosphorus content is 89.8%.
TABLE 1
5/28 Properties of the pulverulent red phosphorus material of
examples 1 to 11
Acid-soluble
Phosphine
phosphorus
formation*
compounds*
Example
Stabilizer
mg PH 3 /(g*day)
mg P/(g*day)
1
0.1% Ag
0.87
34.3
2
0.2% Ag
0.02
35.6
3
0.3% Ag
0.02
37.6
4
0.2% Ag, 2% SnO*H 2 O
0.02
4.8
5
0.2% Ag, 2% Mg(OH) 2
<0.01
33.5
6
0.2% Ag, 2% Al(OH) 3
0.90
16.0
7
0.2% Ag, 2% SnO*H 2 O
<0.01
1.2
8% epoxy resin
8
0.2% Ag, 2% SnO*H 2 O
<0.01
0.1
8% melamine resin
9
2% SnO*H 2 O
0.80
5.2
(com-
parison)
10
8% melamine resin
0.06
3.5
(com-
parison)
11
2% SnO*H 2 O
0.02
0.2
(com-
8% melamine resin
parison)
*after aging in hot and humid conditions (80° C. and 100% atmospheric humidity)
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The invention relates to a stabilized, pulverulent red phosphorus material composed of phosphorus particles whose particle size is not more than 2 mm, and whose surface has been covered with a thin layer of an oxidation stabilizer, wherein the oxidation stabilizer is silver, and also to the use of the same, and to a process for its preparation.
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BACKGROUND OF THE INVENTION
This invention relates to a distilled water production device. More specifically, this invention relates to a distilled water production device in which cooling water which has passed through a condenser is fed to the boiler.
In a small-scale distilled water production device in which the cooling water that has passed through the condenser is fed to the boiler, it is necessary to suppress the flow rate of the water supplied to the boiler so as not to cause a reduction in the boiling capacity. In existing models of distillation devices this is done by adjusting the flow rate with a manually-controlled valve. Consequently, there is the problem that when the pressure on the primary side of the manual valve (the primary water supply pressure) fluctuates, so does the flow rate and, hence, so does the amount of water supplied to the boiler.
SUMMARY OF THE INVENTION
An object of the invention is to provide a distilled water production device in which cooling water which has passed through a condenser is fed to a boiler.
Another object of the invention is to provide a distilled water production device in which cooling water is supplied to a boiler from a condenser at a predetermined rate of flow.
A further object of the invention is to provide a distilled water production device in which the rate of flow of cooling water supplied from the condenser to the boiler may be adjusted as desired independently of the flow of cooling water through the condenser.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view showing an embodiment of the invention.
FIG. 2 is an enlarged cross-sectional view showing the overflow tube in the FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a boiler 1 has a heater and produces steam. It is connected to the condenser 3. The steam from the boiler 1 is condensed in the condenser 3. The distilled water produced in this condenser 3 flows out through the outflow pipe 5 to the water storage tank 7, where it is stored. Inside the above-mentioned distilled water storage tank 7 there is a float switch 9 which senses the level of the distilled water. At the top of this tank 7 there is an overflow pipe 13 which is connected both to the tank 7 and to the water outflow pipe 1. In addition, at the bottom of the tank 7 there is a regular stopcock 15. Consequently, by firing up the heater which heats the boiler 1, steam is produced which is supplied to the condenser 3, where it is condensed; it then flows out and is stored in the tank 7 and can be drawn off to be used by operating the stopcock 15.
Along the water supply flow path 17 through which cooling water is supplied to the above-mentioned condenser 3, there are a strainer 19, a flow rate control valve 21 which has a pressure compensator and maintains the flow rate constant regardless of fluctuations in the pressure of the primary water supply, and a solenoid valve V1 which opens and closes the supply path, in that sequence. An overflow tube 25 is connected to the outflow path 23 for cooling water from the condenser 3. This overflow tube 25 is also connected to the above-mentioned outflow pipe 11 via a connecting pipe 37. A branch path 27 is connected from the overflow tube 25 to the above-mentioned boiler 1. The flow rate of the cooling water which is supplied to the condenser 3 through the supply path 17 is maintained constant by the action of the flow rate control valve 21. Part of the cooling water which passes through the condenser 3 branches off through the branch path 27 of the overflow tube 25 and is supplied to the boiler 1.
An outflow path 29 connects the above-mentioned water outflow pipe 11 to the above-mentioned boiler 1. Provided along this outflow pipe 29 are a water level sensor 31 which senses the water level inside the boiler, an opening and closing valve 33 and a solenoid valve V2, in that order proceeding from the end connected to the boiler 1. Consequently, the water level inside the boiler 1 can be determined by use of the water level sensor 31 and, by appropriate operation of the opening and closing valve 33 and the solenoid valve V2, the residual water inside the boiler 1 containing concentrated impurities can be removed.
The above-mentioned overflow tube 25 might, for example, have the configuration shown in FIG. 2. That is to say, the overflow tube 25 could be divided into an upper chamber 25U and a lower chamber 25L by the flow dividing plate 35 with a small hole 35a in it. The above-mentioned outflow path 23 for cooling water from the condenser is connected to the upper chamber 25U. Both the above-mentioned branch path 27 which is connected to the above-mentioned boiler 1 and the connecting pipe 37 which is connected to the outflow pipe 11 are connected to the lower chamber 25L of the overflow tube 25. The above-mentioned connecting pipe 37 penetrates a considerable distance into the lower chamber 25L; its upper end extends above the above-mentioned branch path 27 and approaches the underside of the flow divider plate 35. A pipe 39, which has a cross-sectional area much larger than that of the above-mentioned small hole 35a, penetrates through the above-mentioned flow divider plate 35. This pipe 39 is displaced laterally from the above-mentioned outflow path 23 so that the cooling water from the outflow path 23 will not flow directly into the pipe 39. The upper end of the above-mentioned pipe 39 sticks up a suitable distance above the flow divider plate 35, and the lower end penetrates into the above-mentioned connecting pipe 37. In addition, the lower part of the pipe 39 passes through an interference plate or baffle 41 which prevents water which passes through the small hole 35a from directly entering the connecting pipe 37. It is desirable for the pipe 39 to be connected to the flow divider plate 35 by some means such as screw threads which permits the height which the top of the pipe 39 sticks up above the flow divider plate 35 to be adjusted.
In the configuration described above, part of the cooling water which flows into the upper chamber 25U of the overflow tube 25 from the condenser 3 passes through the small hole 35a in the flow divider plate 35 and flows over baffle 41 into the lower chamber 25L and is supplied to the boiler 1 through the branch path 27. The greater part of the cooling water which flows into the above-mentioned upper chamber 25U overflows over the top end of the pipe 39 and flows out through the connecting pipe 37 to the outflow pipe 11. Consequently, the height of the cooling water inside the upper chamber 25U of the overflow tube 25 (the water head) is held constant, so that the amount of water supplied to the boiler 1 through the small hole 35a in the flow divider plate 35 is held constant. If it should become necessary to vary the amount of water supplied to the boiler 1 due to a change in the evaporation capacity of the boiler 1, the height which the pipe 39 sticks up above the flow divider plate 35 can be adjusted to vary the water head in the upper chamber 25U of the overflow tube 25.
As can be understood from the above description of a particular embodiment, even in a case in which the water pressure and flow rate of the primary water supply to the condenser fluctuate, the flow rate of water supplied to the boiler is held constant by the action of the overflow tube. Consequently, there is no problem with the evaporation capacity of the boiler being reduced due to excessive supply of water.
The usefulness of this invention is not limited to the particular embodiment described above. By making suitable modifications it can be used in other embodiments as well.
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A distilled water production device in which cooling water from a condenser is supplied to the boiler at a constant rate. The device is provided with an overflow tube on the outflow conduit for cooling water from the condenser which diverts excess cooling water away from the boiler to a discharge pipe.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of International Application No. PCT/EP2003/014664, filed Dec. 19, 2003, which was published in the German language on Jul. 15, 2004, under International Publication No. WO 2004/059164 A1 and the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to a metering pump assembly for admixing a fluid reduction agent to an exhaust gas flow, with an assembly housing which accommodates an electrical drive, a transmission, a membrane pump, and control and regulation electronics
With auto-ignition internal combustion engines, on operation with an excess of oxygen, which is the case in the majority of operating conditions, nitrogen oxides arise, and specifically for example with direct injection into the main combustion space, as is typically the case with diesel motors. It is known to lead the exhaust gas flow to a reduction catalyser in order to reduce these environmentally harmful NO x emissions. An aqueous urea solution as a reduction agent is led to the exhaust gas in a finely distributed manner before entry into the catalyser. At the same time the quantity of fed urea is to be matched as exactly as possible to the combustion process, in order to ensure as complete a reduction as possible within the catalyser and on the other hand to avoid an excess of urea. For this purpose, separate control and regulation (closed-loop control) electronics are required which control the supply of urea in dependence on the variables which are characteristic of the combustion and reduction process (temperature upstream and downstream of the catalyser, the air volume led to the combustion process, NO x and O 2 content of the exhaust gas).
It is known from German published patent application DE 44 36 397 A1 to apply a metering valve in order to supply the aqueous urea solution in the quantity which is required at just this respective moment. At the same time, the delivery of the urea solution is effected by way of the application of pressure to a supply tank with pressurized air, which in turn also serves for entraining the urea solution into the exhaust gas flow.
The setting of the urea supply container under pressure, in combination with a metering valve directly in front of the injection location, has disadvantages which are inherent to the system. In this respect, that which is more favorable is the application of a metering pump which suctions the aqueous urea solution from an essentially pressure-free supply container and leads this in a targeted manner to a pressurized gas, in particular to a pressurized air flow which is led then via a nozzle to the exhaust gas flow in a finely distributed manner directly upstream of the catalyser. Such an arrangement is particularly preferred for a mobile application in motor vehicles, and is known for example from U.S. Pat. No. 5,842,341.
Metering pumps are applied in many technical fields, but are usually stationary. Such a metering pump manufactured and marketed by the company Grundfos, Denmark is known under the type descriptions DME and DMS. These pumps are designed and conceived for stationary application and are therefore suitable only to a limited extent for the application purpose being discussed here.
BRIEF SUMMARY OF THE INVENTION
Against this state of the art, it is the object of the present invention to provide a metering pump assembly which is specially designed for admixing a fluid reduction agent into an exhaust gas flow, in particular of a motor vehicle.
According to the invention, the metering pump assembly described at the outset has an assembly housing comprising at least parts of a pre-mixer in which the fluid reduction agent is subjected to a pressurized gas flow. Advantageous embodiments of the invention are described in the following description and the drawings.
The basic concept of the present invention is the provision of the metering pump assembly with further components for this special application purpose, which are usefully to be arranged in the assembly housing. At the same time, depending on the design, only parts of the pre-mixer or this too may be arranged completely in the assembly housing, including the auxiliary assemblies required for this. This is particularly advantageous for application in vehicles, where the assembly of individual components is to be avoided whenever possible, since on the one hand the components should be encapsulated from the harsh influences of the environment, on the other hand the components should be mounted with low oscillation, and finally restriction or removal of installation space for other assemblies should be allowed.
The pre-mixer which, according to the invention, is arranged at least in parts within the assembly housing serves first for subjecting the liquid reduction agent (generally an aqueous urea solution, for example a 30% urea solution) to a pressurized air flow in order then to feed this pre-mixed mass flow to the exhaust gas flow in a manner such that it is distributed as finely as possible by way of a nozzle arranged in the exhaust gas flow directly upstream of the catalyser. At the same time, the metering pump ensures that only just that quantity of urea solution is fed which is required for the reduction of the nitrogen oxides.
Since urea which is maintained in aqueous solution, on contact with air, thus in particular also pressurized air, may at least partly crystallise out, which may lead to sticking, restrictions and blockages in the conduit system, according to a further formation of the invention means for blowing out the conduit parts coming into contact with the fluid reduction agent as well as with the pressurized gas flow are provided, thus at least for the conduit parts which lie downstream of the location at which the two flows meet.
In order to render this possible, a first valve is arranged within the assembly housing, which in a first switch position connects a conduit leading the pressurized air flow to a conduit leading to the exhaust gas flow for the purpose of blowing out this conduit, and in a second switch position connects the exit conduit of the pump to the conduit leading to the exhaust gas flow, thus forms the normal operational position. Thus, without further technical accessories and while using pressurized air which is available in any case, one may achieve a blowing-out of the corresponding conduit parts by way of a suitable activation of this first valve, in order to protect to a large extent these conduit parts from urea deposits.
On the other hand, before operation of the pre-mixer it is to be ensured that the conduit system, in particular from the exit of the pump up to the mixing location, is completely filled with fluid reduction agent, since only then does the admixed quantity of reduction agent correspond to the quantity delivered by the metering pump. For this purpose, according to the invention, means are provided for flushing and/or bleeding the conduits leading the reduction agent, and specifically within the assembly housing. In this connection, a second valve—hereinafter called pre-flushing valve—is arranged within the assembly housing, by which the exit conduit of the pump may be selectively connected to a conduit, which leads to the tank for the reduction agent, or to a conduit leading to the first valve or to the exhaust gas flow. The latter position is the operational position. For the starting operation of the pre-mixer, the pre-flushing valve is controlled into the first-mentioned position and the metering pump is switched to permanent operation, so that the conduit is continuously flushed with liquid reduction agent, which then flows back into the supply container. On account of this, one reliably ensures that the conduits leading the reduction agent are completely filled with the agent.
Usefully, the assembly housing is constructed of several parts which are functionally separated from one another, and specifically in a manner such that one housing part is provided for the electronics, another housing part for the drive motor and the drive mechanics, and a further housing part for the components leading the fluid, such as conduits, conduit connections, valves and membrane pump. At the same time, the drive mechanics are preferably arranged in the middle housing part, and the electronics to one side and the fluid-leading components to the other side of this middle housing part. Such an arrangement not only encourages the operational reliability of the assembly, but is also advantageous in the case of repairs since, for example, exiting reduction agent may not come into contact with mechanical or electronic components.
It is to be understood that the valves are usefully arranged in the fluid-leading part of the pump housing, just as the conduit connections, thus preferably also the connection for a pressurized air supply conduit for the supply of the assembly with pressurized air.
Since the pressurized air conduit, particularly with vehicles, is usually under operating pressure, on the assembly side it is useful to provide a shut-off valve for the conduit leading pressurized air, in order to be able to shut off the supply of pressurized air when required.
In order to prevent fluid reduction agent from penetrating into the pressurized air conduit, for example in the case of a pressure drop, and this becoming possibly restricted due to the crystallisation of the urea, a return valve is usefully provided in the conduit leading the pressurized air, and specifically downstream of the shut-off valve in the through-flow direction. This return valve usefully likewise lies within the assembly housing, and specifically in the housing part for the fluid-leading parts.
In order to be able to exchange the complete assembly in a quick and simple manner for repair or maintenance purposes, it is useful to provide in each case a conduit connection on the assembly housing for all conduits leading fluid, the connection being envisaged for the releasable connection to a corresponding connection conduit. This, in a simple form, may be formed by a connection spout (union) onto which a flexible tubing may be pushed, but also by flexible tubing coupling systems. Since, preferably, digital control and regulation electronics are present in any case within the assembly housing of the metering pump assembly, it is useful to also arrange the control and/or regulation electronics within the assembly housing, these electronics being necessary for the reduction process and the valve-control.
According to the invention, the assembly housing may also encompass parts of the pre-mixer. Thus the actual mixing procedure between the conduit leading the reduction agent and the conduit leading the pressurized air may take place outside the assembly housing, if this is advantageous. According to a preferred formation of the invention, however, the assembly housing does not comprise the complete pre-mixer. This is not only favorable with regard to design, but also with regard to extreme operating conditions, such as at low temperatures as regularly occur in the operation of motor vehicles. One may then ensure the operational reliability of the complete pre-mixer by way of provisions on the part of the assembly housing, without having to make further provisions on the part of the vehicle.
In order to be able to apply the metering pump assembly in vehicles which realize the control and/or regulation electronics for the reduction process and the valve control by way of the digital motor electronics, as well as in those with which such control and/or regulation electronics are not provided, it is useful to provide the regulation (closed-loop control) electronics or at least parts of the regulation electronics as a housing module, which is preferably releasably attached, so that the metering pump assembly may be applied with or without such a module depending on the application purpose.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
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:
FIG. 1 is a schematic block diagram illustrating the pre-mixer with its auxiliary assemblies, the exhaust gas conduit system and the reduction catalyser, according to an embodiment of the invention;
FIG. 2 is a block diagram of the pre-mixer of the metering pump assembly according to and embodiment of the invention; and
FIG. 3 is a metering pump assembly according to the invention in a simplified, partly sectioned, perspective view.
DETAILED DESCRIPTION OF THE INVENTION
The exhaust gas conduit 1 of a diesel motor is shown in FIG. 1 , whose through-flow direction is indicated at 2 . The warm exhaust gas coming from the combustion engine flows through the conduit 1 first past a sensor 3 , which detects the nitrogen oxide content and the oxygen content. In the through-flow direction, a nozzle head 4 lies downstream of this, via which a flow comprising pressurized air and fluid reduction agent in the form of aqueous urea is led to the exhaust gas flow 2 in a finely distributed manner. A reduction catalyser 5 , after whose exit the exhaust gas leaves the system through the free end 6 of the conduit, connects directly downstream of this. In the flow direction, temperature sensors 7 are provided in each case upstream and downstream of the catalyser 5 .
The nozzle head 4 is supplied by a conduit 8 which comes from a metering pump assembly 9 , as is shown by way of FIGS. 2 and 3 . The metering pump assembly 9 comprises an assembly housing 10 , which is divided into essentially three regions 11 , 12 , and 13 . The housing part 11 , which connects to an end-face of the housing 10 on the one hand, comprises the control and regulation electronics for the metering pump as well as furthermore the control and regulation electronics for the reduction process. These control and regulation electronics may be connected to the motor electronics via a CAN-bus and furthermore detect the signals of the temperature sensors 7 , the sensor 3 and the air mass flow led to the combustion procedure which is symbolised in FIG. 1 by the arrow 14 .
A housing part 12 connects to the housing part 11 for the electronics, and this housing part 12 comprises the drive motor in the form of a stepper motor 15 , as well as an eccentric gear 16 which steps down the rotational movement of the motor 15 and converts this into a translatory movement, which drives the actual membrane pump 17 , which is seated in a housing part 13 connecting to the housing part 12 and comprising all fluid-leading parts of the assembly. The housing part 13 is separated from the housing part 12 by way of an intermediate wall (not shown) so that in the case of an inadvertent escape of fluid, be it on repair or with a leakage, it is ensured that the fluid may not penetrate into the housing parts 11 and 12 .
The housing part 11 is designed in a divided manner and comprises a part which is integrally formed with the remaining housing 10 and which comprises the control and regulation electronics for the motor 5 , as well as a removable housing 11 a, which connects thereto at the end-face and which comprises the electronics required for the control and regulation of the reduction process. In this manner, the assembly may be applied selectively with or also without these control and regulation electronics for the reduction process. The housing part 11 a is designed in a modular manner and is connected electrically to the remaining electronics by way of plug-and-socket connections, and is also releasably connected to the housing part 11 in a mechanical manner. The actual membrane pump 17 with the associated return valves is located within the housing part 13 . Furthermore, four connections 18 are provided on the housing part 12 to which conduits are releasably connected and which are shown in detail in FIG. 2 .
The membrane pump 17 as well as a pre-mixer 19 is arranged in the housing part 13 . The pre-mixer 19 comprises a first 3/2-way valve 20 , a second 3/2-way valve as a pre-flushing valve and a shut-off valve 22 , as well as a throttle location 23 .
The functions and the conduit connections and the valves operate as follows.
Before the start of the operation of the pump assembly, with the pre-mixer 19 it must be ensured that the conduit 24 on the pump exit side is filled with fluid reduction agent. For this purpose, the pre-flushing valve 21 is activated in a manner such that the conduit 24 on the pump exit side is connected to a return conduit 25 , which conveys the fluid reduction agent back into a supply container 26 . The reduction agent is suctioned and delivered towards the pump 17 from the supply container 26 .
After the flushing has been effected and it is thus ensured that the conduit 24 leads the liquid in a complete manner, the pre-flushing valve 21 is changed over, by which the conduit 24 on the pump exit side is connected to the entry of the valve 20 , which in the operational position is connected such that a conduit connection to the conduit 8 exists which feeds the nozzle head 4 . Reduction agent gets into the conduit 8 via this conduit lead. Pressurized air, which is supplied via a connection 18 and a conduit 27 , goes through the opened shut-off valve 22 to the throttle location 23 and from here via the mixing location 28 into the conduit 8 , so that with a suitable delivery of the pump 17 and impinging of the conduit 27 with pressurized air, the desired pre-mixing is effected and is led via the conduit 8 (likewise via connection 18 ) out of the assembly housing.
The metering of the reduction agent is effected in a manner known per se, dependent on operation, with the help of control and regulation electronics. On completing the operation, thus for example when the internal combustion engine has been switched off, the valve 20 is re-routed in a manner such that the conduit 27 leading pressurized air while bypassing the throttle location 23 is directly connected to the conduit 8 . In this manner, the part of conduits leading the reduction agent which lies on the other side of the valve 20 , thus also the part which lies on the other side of the mixing location 28 is supplied with pressurized air, by which the reduction agent remaining in the conduit is blown out via the nozzle 4 , and thus the conduit system itself may not become contaminated by urea which crystallises out.
The four connections 18 of the housing part 13 are thus connections for the suction conduit 29 of the pump 17 , for the return conduit 25 to the supply container 26 , for the supply of pressurized air to the conduit 27 , and for the conduit 8 .
The electrical and sensor connections are provided on the housing part 11 . The assembly housing is designed in a compact manner and hermetically sealed, so that it may be installed at any location in the motor space. The assembly is electrically designed for supply from the vehicle's own electricity supply, for example 12 volts or 42 volts. The supply container 26 for the reduction agent is non-pressurized and may therefore be arranged at any location in the vehicle, and no special provisions are required, as is the case with pressurized containers. The pressurized air which is required for operation of the pre-mixer may be taken from the vehicles own pressurized air supply or may be provided by way of a separate compressor.
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 dosing pump assembly ( 9 ) is provided which is adapted to admix a liquid reducing agent to an exhaust gas flow. The dosing pump assembly includes an assembly housing ( 12 ) that houses an electric drive ( 15 ), a transmission ( 16 ), a membrane pump ( 17 ), and control and/or regulating electronics. The assembly housing ( 10 ) further includes a pre-mixing device in which the liquid reducing agent is impinged upon with a pressurized gas flow.
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This application is a continuation of application No. 216,446, filed Jan. 10, 1972, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the invention
This invention relates to certain new and useful improvements in apparatus for electroplating bulk parts.
2. Description of the prior art.
The electroplating of small metal or plastics parts on an industrial scale is today more and more widely carried out, for reasons of economy, in bulk within bell or drum-shaped containers. It is then possible for a bulk-mass of the small parts to be loaded into the containers, which being perforated can be partly dipped or wholly immersed in the appropriate electrolytes or other treatment liquids, and rotated therein. It has to be borne in mind that before the start of the electroplating process proper it is or may be necessary chemically to roughen the surface of bulk-parts made of plastics, generally by etching their surfaces, and thereafter to coat the roughened surfaces and render them electrically conductive by subsequent so-called electroless metal-deposition of a metallic layer. The conventional perforated bell-shaped or drum-shaped containers used for these purposes are generally known as tumbling barrels, and there are a variety of such conventional tumbling barrels which differ in their construction, dependent especially upon their intended use, above all according to whether they are meant for electroplating bulk parts made of metals or of plastics. The different forms of construction of the conventional tumbling barrels are thus influenced by the various properties which characterize the particular kind of bulk parts under treatment, above all by whether they are formed of metals or of plastics. There are no known tumbling barrels which are capable, with a standard constructional shape and unaltered method of operation, of properly satisfying the functional requirements which are both necessary and desirable for selectively bulk-electroplating parts made either of metals or of plastics in one and the same tumbling barrel.
In order clearly to see the deficiencies in the tumbling barrels of the prior art and to recognize the advantages of the solution provided according to the present invention it is convenient first to define those requirements which must be met for electroplating bulk parts made of plastics but to which an electroless-deposited metallic coating has been applied - because for the most part the same requirements are also of critical significance for the bulk-electroplating of parts made of metal.
When electroplating a bulk-mass of parts made of plastics and covered with an electrically-conducting metal layer, these usually float or are suspended in the electrolyte; but they will also sometimes sink to the bottom of the rotating container, whenever the average specific weight of the individual plastics part is greater or has grown greater than that of the electrolyte or other treating solution in the bath. The specific weights of the plastics themselves are mostly smaller than those of the electrolytes (around 1.040 g./c.c. for ABS-polymers as against 1.120 g./c.c. for a cyanide copper bath or 1.166 g./c.c. for a nickel bath) but the average specific weight of each individual part increases as the electrolessly-deposited metallic coating is built up on the surface of the part. The average specific weight of any part may be calculated as the quotient secured by the division of the sum made up of the weights of the plastics part and its continually-growing metal coating on the one hand by the total body volume of the part on the other hand.
With that in mind, the considerations affecting the problem may be enumerated as follows:
1. Contact Pressure
The force bringing two adjacent plastic parts in the bulk mass together in order to establish electrical contact between them as they are suspended in the electrolyte is extremely small due to the minimal difference between the average specific weight of the metal-coated plastic parts and the specific weight of the electrolyte.
2. Intermixing
In order to ensure the uniform appearance of all the parts in the load after electroplating it is necessary throughout the electroplating operation continuously to alter the position of each part relative to the load as a whole.
3. Relative Movement
Equally, in order to achieve a uniform appearance in the electroplated product it is necessary for the parts to be continuously moving throughout the electroplating operation at differing speeds with respect to each other.
4. Fluid Boundary Layer
Whatever the nature of the plastics part itself, metal surfaces are generally not hydrophobic, and the metal-coated surface of the plastic part is therefore wetted by the electrolyte, which clings to the surface in the form of a layer which moves around with the part at the same speed.
5. Break up of the Electric Field
The efficient electroplating of the rotating load of bulk parts takes place effectively at and in its peripheral zone. The electrical field is formed in the electrolyte between the anode (situated outside the immersed barrel) and the cathodically-polarized load (situated inside the barrel) but this field breaks down - in accordance with the Faraday cage-effect - at the edge of the polarized load, and is able to penetrate this only to an insignificant extent. Thus electroplating is confined practically to the edges of the load.
6. Electrolyte - exchange
A continuous turnover of the electrolyte at the cathode surface is advantageous, particularly as regards the deposition of polished platings, since this avoids impoverishment of the electrolyte adjacent the surface in the metal ions to be deposited and also removes the air bubbles present as well as the gas bubbles arising from the flow of electric current, which can stick to the surface of the bulk parts and cause local impediments to the deposition of the metal. The impoverishment of the electrolyte in the metal ions to be deposited and the formation of gas bubbles both take place principally where the current densities on the cathode are largest that is to say in the edge zones of the load, and thus at the peripheries of the rotating barrel. Thus electrolyte-exchange is particularly important at the peripheral circumference of the rotating tumbling barrel.
The considerations discussed at (1) to (4) above lead to the creation in actual practice of a hypothetically-avoidable film of electrolyte, varying in thickness, between the adjacent bulk parts. The existence of this separating film of electrolyte leads to certain undesirable consequences, as follows:
a. Bi-polar Effects
The electroplating current flows from the anode, constituting the positive pole of the system and situated outside the electroplating tumbling barrel, through the electrolyte in the electroplating bath and through the load (or more strictly through the metal "skin" on the plastics parts) right through to the cathodic contact elements, constituting the negative pole of the system, which are situated in the rotatable tumbling barrel. However when the individual parts are separated ("insulated") from one another by a film of electrolyte then on the individual plastics part the metal coating retains the function of an electrical interconnector, but the part acts as a bi-pole within the load. One area on its metallic surface displays a cathodic potential and another area, electrically-speaking diametrically opposite thereto, displays an anodic potential. Thus local galvanic cells are set up between adjacent plastics parts, oriented in the direction in which the electroplating current flow. Bipolar effects unfortunately cause at least partial electrolytic redissolution of the metal coating (no matter whether deposited electrolessly or galvanically) in those areas of the surface of the parts which (temporarily in the course of the rotational movement) are at anodic potential. Consequently such bi-polar effects lead to the reversal of the desired proper electroplating effects. Moreover, these bi-polar effects also lead to the electrolytic formation of metal oxides on the metallic coating layer during its local, anodic polarization, thereby causing rough and matt surfaces which are unsuitable for purposes of decoration.
b. Unhomogeneous Partition of the Electrical Potential
The electroplating current does not distribute itself uniformly, and anyway its pattern of flow is not easily visible and cannot be controlled. The consequence is a lack of uniformity in the appearance of the bulk parts and - within the limits of the decreasing potential differences of the individual bulk parts with respect to the anode system -also a substantial decrease in the speed of electrolytic deposition, thus in the electroplating performance.
c. Chemical Corrosion
It is impossible completely to eliminate the chemical attack of the electrolyte on the metal coating upon the plastics part in the bath, owing to the breakdown of the electrical field at the edge of the load, and this corrosive effect of the solution is significantly promoted by the existence and extent of the separating films of electrolyte. The resultant corrosion leads to the chemical redissolution of the deposited metal; and almost always also leads to the chemical oxidation of the surface of the deposited metal.
d. Burn Patches
The phenomenon of so-called burn patches occurs either upon the conductive electrolessly-deposited coating or upon the subsequent galvanically-applied electroplating upon the plastic parts. These burn patches appear not as points but are spread over areas which generally cover a considerable part of the surface of the part. Their occurrence can be explained as follows. Galvanic baths mostly are worse electrical conductors than metals; their respective conductive capacities for electricity differ by a ratio whose order of magnitude is about 1:10 5 . As indicated at (a) above, the setting up of local galvanic cells between the adjacent bulk parts is to be expected; and the passage of current is then concentrated (in the region involved in the transmission of current from one part to the other) first of all on a gap which spatially is almost point-shaped, comprising the electrically-opposed, polarized areas of the metal coatings on two adjacent bulk parts and the electrolyte film lying between them. The Joule heat evolved corresponds to the product of the electric current i squared and of the electrical resistance R of the system. The resistance R is minimal if metal bridges are in existence, that is if direct metal contacts have been established between one part of the load and another; but on the other hand the resistance R suddenly jumps if the current conduction has to take place across a bad electrical conductor, to be specific in this case across an intervening film of electrolyte. It ought also to be borne in mind that on the anodic side of the system (consisting of two adjacent bulk parts) redissolution of the metal layer as well as oxidation of the surface is liable to take place; both of these effects lead to impairment of conductivity, for metal oxides are well known to be generally bad electrical conductors. Thus, all these previously-described effects may be superimposed to bring about a localized high total resistance R, and thus an excessive, local generation of heat. This results in dark violet-coloured burn patches and circular spots on the surface of the bulk parts, which may also be partially or completely stripped of their metal covering layer by these electrolytic and thermal reactions. Dark burn patches and de-metallized spots on the bulk parts are not rare occurrences; on the contrary it is a not uncommon experience for anyone with knowledge of this field to encounter a completely failed load, in which virtually all the bulk parts - piece after piece-prove to be unuseable.
The known tumbling barrels include those of prismatic or cylindrical shape arranged to rotate around their horizontal axis of symmetry, which dip only a relatively small part of their volume into the electrolyte and possess an opening centrally-located in one of the two end walls mounted perpendicular to the axis of rotation, this opening serving for loading or unloading the batch of metal bulk parts. Since this opening remains essentially free during the electroplating it need not be covered with a lid. Tumbling barrels of the kind just described are however unsuited for electroplating metallized plastics parts, as these float or are suspended in the electrolytic solution in the bath.
Alternatively, tumbling barrels of prismatic shape with a hexagonal cross-section have been marketed, which similarly rotate about their horizontal axis of symmetry but have an opening for loading or unloading the batch on the peripheral circumference of the casing, which of course must be closed by means of a lid during electroplating. These barrels have a length of about 550 mm. and an average casing diameter of about 200 mm. The electroplating current is carried to the load via two insulated cables which are individually introduced within the barrel through the two axial bearings which support the barrel at or adjacent its end walls, and these cables terminate in smooth, metallic, cylindrical contact elements, about 200 mm. long and about 12 mm. in diameter. This type of tumbling barrel can be used without constructional alteration for electroplating bulk parts no matter whether made of metal or made of plastics - though the conditions of application have to be altered appropriately. When electroplating bulk parts made of metal such tumbling barrels can be immersed completely or nearly completely in the electrolyte, but when electroplating bulk parts made of plastics, then according to Muller, G., "Galvanisieren von Kunststoffen", published by E. G. Leuze Verlag, Saulgau, (1966), pgs. 104-105, one must
".....allow these commercially-available electroplating barrels to be dipped only partially, that is up to one third to 50%. In this way the goods are compelled to pack together at the bottom of the barrel and a more constant contact is established. Since however like this only a very small volume of liquid is effective, the current densities which can be employed are very small, resulting in long treatment times. The constant rising of the contacts out of the liquid leads to the passivation of the electrical contacts." It is in fact standard industrial practice to load tumbling barrels with a batch of parts - irrespective of whether those parts are made of metal or plastics - which fills only from about one third up to at most one half of the space within the barrel. Experience has shown that when filled with larger quantities the intermixing of the load during electroplating becomes unsatisfactory, resulting in unevenly-electroplated bulk parts and very long electroplating times.
A tumbling barrel has been proposed in U.S. Pat. No. 3,330,753 which consists principally of two end walls vertical to the axis of rotation, an outer casing fixed between these end walls and surrounding an inner, concentrically-arranged coaxial cylinder, and several rod-shaped cathode contacts extending between the end walls in the annular space between the outer barrel casing and the inner cylinder. It is there suggested that this annular space within the barrel should be filled as nearly full as possible so long as the bulk parts can still move; the purpose of filling the barrel nearly full is to restrict the room for movement of the plastics parts as much as possible in order to force them to the opposite electrical contact.
However, this has its disadvantages. As explained at (5) above, the electrical field breaks up at the peripheral circumference of the large-volume load. Since the majority of the bulk parts lie within the conglomerate mass they consequently are effectively shut off from the galvanic plating process, and as explained at (a), (c) and (d) they run increased risk of bi-polar effects, of chemical corrosion by the electrolyte, and of the formation of burn patches. Moreover, it is also easy to see the irregular distribution of the electrical potential field in the load, explained at (b) above, when such a tumbling barrel is put into use. Thus for example when the bulk parts are relatively small, by opening the barrel lid and reaching into the load one can clearly see that the bulk parts near the peripheral circumference have already been plated with electrolytically-deposited metal at a time when parts located well inside of the batch have been electroplated only very slightly or even not at all. This means at best that extremely long electroplating times are needed, while the platings produced on the bulk parts in the load are liable to look uneven, varying from matt to brightly-shining.
Tumbling barrels have been proposed in German Pat. Nos. 277,128 and 281,032 whose length is smaller than their diameter, and whose end walls normal to the axis of rotation are perforated. The barrel according to German Pat. No. 277,128 has a peripheral casing of metal, which serves as the cathode contact element for the batch loaded into the barrel. The direct current needed for electroplating is led to the casing via a flexible metal band, which extends more than half way around the electrically-conductive barrel casing and at the same time holds the barrel in its operative rotating position. The barrel according to German Pat. No. 281,032 makes cathodic contact with the batch via a metal hoop fastened on the inside of the peripheral barrel casing. The direct current needed for electroplating is led to the contact hoop along several radially disposed spokes, which radiate from a metal driving wheel (for rotating the barrel) secured concentrically with the barrel.
However the two different sorts of tumbling barrels proposed in German Pat. Nos. 277,128 and 281,032 have not found favour in industrial practice, for several reasons. The current-conducting elements of the barrels (the flexible band, the spokes and the driving wheel) all quickly become covered with electrolytically-deposited metal, since the electrical resistance between them and the anode system tends to be much smaller than that between the cathodically-polarized load enclosed within the barrel and the same anode system. As a direct consequence of this unwanted metal deposition the barrel in each case may become incapable of functioning mechanically within quite a short time.
A further important reason for the practical failure of the tumbling barrels just described above lies in the deviation of the electroplating current away from the load of bulk parts. The tendency is for most of the electroplating current to flow to the barrel elements at cathodic potential (flexible band, spokes and driving wheel) so that only a fraction of the electroplating current flows to the barrel and reaches the load, because the cathodic contact elements (the contact casing and the metal hoop) on the periphery of the barrels not only display a higher potential difference but also have a more favourable position with respect to the anode system than the load. As explained at (5) above, the electroplating process takes place at the edge of the load; and from this it is self-evident that the disposition of the contact-casing and -hoop on the outside of these conventional barrels causes them to draw a considerable part of the remaining galvanic current to themselves, to the detriment of the load. For the reasons explained at (a), (b), (c) and (d) above, the resultant galvanic platings will tend to be rough and matt, possibly dark-violet and of generally differing aspect, so that one gets a possibly useless product even after very long electroplating times.
Yet another disadvantage of these same conventional tumbling barrels derives from the fact that, as previously indicated they are filled with the load only to about a third of their volume. There is consequently only a small specific contact pressure between the individual bulk parts made of plastics and between these bulk parts and the cathodic contact elements. This inadequate contact pressure is a direct result of filling not more than a third of the volume of the barrel, and it leads to bi-polar effects and an irregular electrical potential field in the load, thus causing burn patches on the bulk parts, chemical re-dissolution of the deposited metal coatings and hence a regular percentage of supposedly electroplated parts in the load which have to be rejected as useless.
The tumbling barrel according to German Pat. No. 277,128 is particularly unsuitable for electroplating plastics parts, since one of its features is the division of its volume into self-contained compartments.
As explained at (5) above, the electrical field breaks up, as is well known at the peripheral circumference of the load - and the galvanic reaction thus takes place practically only at the edge of the conglomerate of bulk parts. If by F [expressed in dm 2 ] one denotes the external surface (the surface of the peripheral circumference) of the load, and by V [expressed in dm 3 ] one denotes its volume, then the quotient F/V [dm 2 /dm 3 ] defines the specific average value and thus the proportion of the electroplating current I per unit of space of the volume of the load. If the value of this specific quotient F/V is relatively high, then the speed with which electroplating takes place in the barrel is likewise proportionally high. All the conventional tumbling barrels are however characterized by low specific average values F/V of the electroplating current I. This common disadvantage is of extreme importance from a chemical engineering standpoint; it leads to very long electroplating times, and therefore small electroplating throughputs per barrel. This applies just as much when the load consists of metal parts as when it consists of plastic parts.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a novel construction of tumbling barrel such that with a single, standard barrel structure and with a consistent method of application the barrel will fulfil the optimum functional requirements which are necessary for electroplating bulk parts made either of plastics or of metals - and which of course is also easy, robust and efficient to build and operate.
It has now been found that these objectives can be largely or wholly secured by combining three essential features of design, namely:
i. the length of the barrel measured parallel to the axis of rotation must be less than the diameter of the barrel measure normal to the axis of rotation, using the term "diameter" to represent, in drums with a polygonal casing cross-section, an average value between the greatest and the smallest distances of the polygonal sides from their centre of symmetry;
ii. the end walls of the barrel, usually normal to the axis of rotation, must be provided with perforations; and
iii. the barrel must contain an inner peripheral wall, or tube of generally cylindrical cross-section, located within the peripheral casing and co-axial with the axis of rotation.
According to the invention there is provided a tumbling barrel for containing a batch of electrically conductive parts to be electroplated, which barrel comprises
a pair of spaced apart end walls;
a generally cylindrical outer peripheral wall extending between the two said end walls and attached thereto at its ends;
a generally cylindrical inner peripheral wall extending between the end walls co-axially within the outer peripheral wall, the inner peripheral wall being attached to the end walls at its ends, the inner and outer peripheral walls and end walls together defining an annular treatment chamber;
at least one closable opening in the outer peripheral wall to allow the loading and unloading of parts into and out of the treatment chamber;
cathodic contact means for supplying electric current to parts contained within the treatment chamber; and
means mounting the end walls for rotation about the common axis of the inner and outer peripheral walls;
both end walls and the outer peripheral wall having formed therein a multiplicity of perforations and the length of the barrel measured parallel to its rotational axis being significantly less than the average diameter measured normal to its rotational axis.
It will of course be appreciated that the end walls are preferably arranged normal to the axis of rotation of the barrel, and that the peripheral wall or casing and inner peripheral wall or tube while generally cylindrical, may in fact be prismatic.
Using a tumbling barrel of this construction, the batch of bulk parts is loaded into the generally annular treatment chamber between the peripheral casing of the barrel and the inner tube; and as will be apparent from what is said later, it is desirable that the batch should fill approximately two-thirds of this generally annular space within the barrel, so as to attain maximum effectiveness of the electroplating.
None of the known tumbling barrels displays the combination of the three features which characterize the barrel according to this invention; and it is an astonishing fact by adopting these features, i.e. reversing the generally-accepted proportionality between length and diameter of the barrel, by perforating the end walls and by arranging a central inner tube within the barrel it suddenly becomes possible to achieve both quantitative and qualitative improvements, above all in the electroplating of metallized plastic parts.
The astonishing advantages of the barrel construction according to this invention have been demonstrated by comparative tests. Taking the nearest comparable counterpart as the known barrel described in U.S. Pat. No. 3,330,753, which has a length of 300 mm. and a diameter of 220 mm., a barrel was built in accordance with the teachings of this invention which had a length of 90 mm. and a diameter of 400 mm.. Thus the volume of the two barrels was the same, namely 11.5 dm 3 ; and they were filled with equal sized batches (2.8 kg. batch-weight, 5.8 dm 3 volume of the batch) of identical bulk parts, namely buttons made of ABS-polymer (an acrylonitrile-butadiene-styrene co-polymer). Each batch was then electroplated in a shiny nickel-plating electrolyte using the same electroplating-currents and -times and the same number of revolutions of the two barrels under test. The bulk parts nickel plated in the barrel according to the invention showed a high-gloss and uniform spotless appearance, and none of the batch needed to be rejected. On the other hand the bulk parts nickel-plated in the conventional barrel though predominantly glossy showed more or less matt and matt-shiny tinges in the central area of the disc-like buttons, while about 5% of the batch were rejects, and even the remainder were not really satisfactory in appearance on a strict, qualitative criterion. The qualitative improvement in the electroplated coatings produced by the barrel according to the invention was also confirmed by taking sections through individual bulk parts. Moreover, sampling of the bulk parts, by periodically removing some from the barrel according to the invention during the electroplating, showed that their plating was essentially complete after only about 35 minutes as compared with the 70 minutes needed in the known comparison barrel.
A further interesting observation concerns the magnitude of the direct current voltage; maintaining the same electroplating current in both barrels, the electroplating voltage in the barrel according to the invention fell to one third of that needed in the conventional barrel. The results observed are summarized in the following Table, which gives a synopsis of the electroplating times t, the electroplating currents I and the associated direct current voltages U; the voltages for the barrel according to the invention are denoted by the index n, and those for the known barrel by the index b. The electroplating current I varied with time, and in fact increased proportionally to the growth in diameter of the metal coating layers on the plastics parts.
______________________________________t I U.sub.n U.sub.b______________________________________20 mins. 25 Amps 2.5 Volts 3.5 Volts10 " 45 " 2.5 " 4.5 "10 " 70 " 3.5 " 5.5 "30 " 110 " 4.5 " 6.5 "______________________________________
The empirical observations recorded above lead to the astonishing conclusion that the spatial shape of the barrel contributes materially to an improvement in the current conduction from one part to another and from the parts in bulk to the cathode contact elements. From this it follows that the new construction of barrel here proposed must in some way greatly increase the specific contact pressure previously discussed at (1) above, and/or it must decrease or eliminate the electrolyte film between the individual parts previously discussed at (4) above and thereby eliminate the disadvantageous bi-polar effects discussed at (a) above, and/or it must homogenize the electrical potential field in the load previously discussed at (b) above, and/or it must impede the chemical corrosion of the metal coatings on the plastics parts previously discussed at (c) above, and/or it must eliminate the cause of the burn patches previously discussed at (d) above.
The barrel according to this invention is very desirably filled in such a way that the batch of bulk parts completely covers the inner tube with the result that the surface area of the outside of the batch attains its maximum value relative to its volume. This yields a favourable proportionality between the surface area of the outside of the batch and its volume, and thus leads to high specific average values of the electroplating current per unit volume of the batch, so that the resulting electroplating times for the barrel according to the invention are consequently very short.
It has moreover been found that the best results from a chemical engineering standpoint can be obtained if the barrel, irrespective of whether the batch consists of metal-parts of plastics-parts, is immersed completely or almost completely in the electrolyte. If the parts are made of metal (or in the case of plastics parts if they are so heavy that they sink to the bottom of the barrel) then their location beneath the surface of the electrolyte - together with the associated anode system - makes it possible to form an electrical field of high homogeneity, enveloping the periphery of the batch on all sides.
The use of an inner tube within the outer casing of the barrel is an extremely important feature of the invention. It is preferably hollow, though it can be solid, and although it will normally have a circular cross-section, it may in fact have a polygonal cross-section. It must of course extend from one end wall of the barrel to the other, and thus will rotate synchronously with the body of the barrel around the common axis of symmetry.
The advantages which flow from the presence of an inner tube within the tumbling barrels of this invention are as follows:
A. batch Size Increase
The generally annular space within the barrel can and should be filled approximately two-thirds full with the bulk parts. Bearing in mind that a batch of plastics or metal parts will either float or sink in the electrolyte, compelling the space in either the uppermost or the lowermost zone of the generally completely immersed barrel to fill up, it will be appreciated that the inner tube will then be completely surrounded by a batch of plastic parts floating in the electrolyte but on its underside - as may be seen along the line m--n in FIG. 2 of the drawings mentioned subsequently herein - the inner tube is covered only by a thin layer of the bulk parts. Exactly the same effect is obtained, in an inverted position, when the bulk parts are heavier than the electrolyte and sink to the bottom of the barrel. The doubled quantities in each batch which filling the barrel two-thirds full makes possible means that the throughput capacity of the barrel can be more or less doubled for this reason alone.
B. intensive Intermixing of Parts
So long as part of the generally-annular space within the barrel remains unoccupied, the inner tube ensures intensive intermixing, since the parts slide over the inner tube (along the line m--n in FIG. 2 of the subsequently-mentioned drawings) and thus alter their position both relative to one another and inside the batch as a whole. Improved intermixing means improved uniformity and quality of the metal coatings on the bulk parts.
C. fixed Position of Batch
Except when it is rolling and intermixing with the other bulk parts as it passes through the intermixing gap (along the line m--n in FIG. 2), every part keeps its position inside the conglomerate of bulk parts both with respect to the adjacent parts and with respect to the casing of the barrel and the cathode contact elements, throughout the duration of each revolution. In other words, the batch does not as a whole carry out any relative movement with respect to the casing of the barrel; and this "fixed" position (for about two-thirds of the treating time) more or less eliminates all displacements between the individual parts lying one against the other. Consequently it seems that the thickness of the disadvantageous electrolyte film between adjacent parts (and between the bulk parts and the cathode contact elements) as previously discussed at (4) above must be considerably reduced, or indeed the film may be actually broken and penetrated by direct bodily contact between the adjacent parts, i.e. formation of direct electrical contacts between the parts across metal bridges. However abrasive damage to the extremely thin, electrolessly-deposited metal layer (generally about 0.8 μm thick, just sufficient to make the surface of the plastics parts electrically conductive) as well as partial redissolution thereof due to chemical and electrolytic influences must be reduced to a minimum, particularly in the first, critical phase of the electroplating process. Furthermore, the causes and the occurrence of the bi-pole effects, as previously discussed at (a) above, which normally afflict the mass-electroplating of plastics parts, and the passivation of the cathode contact elements (in consequence of too high current densities) seem to be all ruled out.
D. increase in Specific Electrical Contact Pressure
The contact pressure between the floating or sinking bulk parts is very slight, as previously discussed at (1) above, but it is of fundamental importance for the conduction of relatively high electroplating currents, generally exceeding 100 amps. The doubling of the size of the batch causes the average specific contact pressure between the bulk parts to increase approximately in direct proportion. The doubled buoyancy-force (with floating bulk parts) or sinking-force (with sinking bulk parts) contributes materially to an accelerated and reliable operation of the electroplating process.
E. increased Electroplating Current
The annular spatial distribution of the batch in the barrel and the comparatively large diameter of the casing of the barrel together result in an approximate doubling of the outside areas of the batch, and thus makes it possible more or less to double the electroplating current and thus, for this reason alone, to achieve an approximate doubling in the electroplating throughput capacity of the barrel.
The advantages (A) to (E) set forth above are those which result from the presence of the third characteristic feature of the invention, namely the inner tube, when electroplating bulk parts made of plastics or metal using the optimum conditions, thus when the barrel is completely immersed in the electrolyte (particularly with floating plastics parts where the completely immersed barrel prevents the bulk parts which rise buoyantly upwards from projecting out of the electrolyte and being thereby removed from the electroplating process) and when also the batch of bulk parts at least partially covers the surface of the inner tube.
The advantage of the second characteristic feature of the invention, namely the perforation of the end walls, lies in the fact that this opens a path for the electroplating current in an area which is obstructed in the known barrels for electroplating plastics parts, and by opening this path integrates the peripheral zones of the batch adjacent to the end walls of the barrel into the galvanic deposition process.
Basing the calculation upon the dimensions of the previously-described test barrel according to the invention, which is 90 mm in length and 400 mm in diameter, the opening up of the peripheral zones of the batch adjacent to the two end walls results in an approximately threefold effective increase in the electroplating output. The peripheral surface of the barrel casing is 11.3 dm 2 in extent, while the area of each end wall is 12.8 dm 2 , and the volume of the barrel is 11.5 dm 3 . Thus the specific mean value F/V [dm 2 /dm 3 ] of the electroplating current when the end walls are not perforated is F/V = 11.3 dm 2 /11.5 dm 3 = 0.98 dm 2 /dm 3 ; but the specific mean value F/V of the electroplating current when the end walls are perforated is F/V = 36.9 dm 2 /11.5 dm 3 = 3.21 dm 2 /dm 3 . In this particular case the specific mean value F/V of the electroplating current per unit volume of the batch, and thus the speed of the electrolytic deposition, can thus be seen to be increased threefold by the perforation of the end walls of the tumbling barrel according to the invention.
In an electroplating installation utilizing the tumbling barrels of the invention it is best if the anodes are arranged parallel to the perforated end walls of the barrel(s), since it has been found that this arrangement leads to a homogeneous distribution of the electrical field in the electrolyte between the rows of anodes and the peripheral zones of the batch adjacent the perforated end walls of the barrel. The large anode surfaces which result from spreading the anodes out along the two end walls of the bath opposite the perforated end walls of the barrel contribute moreover to the fact that the anodic current densities - despite the very large electroplating currents - are evenly distributed, thus do not exceed their permitted limit, and consequently do not give rise to passivating phenomena at the anodes. The fact that anodes and cathodes are then effectively arranged parallel to each other corresponds to the ideal arrangement for which one should always strive when constructing galvanic cells or systems.
It is also preferred to arrange electroplating installations in accordance with this invention with additional anodes disposed parallel to the axis of rotation of the barrel. These additional anodes not only provide some contribution to the increase in the electroplating current but more importantly they help in homogenising the electrical field in the peripheral area of the barrel.
An electroplating installation in accordance with this invention, consisting of a tumbling barrel as herein described and rows of anodes parallel both to the end walls and to the barrel casing, leads to an electrical field of exceptional evenness over the whole periphery of the barrel. The barrel, which is preferably immersed completely in the bath of electrolyte, is surrounded on all sides (both around the perforated end walls and also around the perforated casing) by anodes and consequently is enveloped by an electrical field of high homogenity, so that the batch is subjected to an intensive and even electroplating process over its whole surface. These favourable conditions lead to very high electroplating currents at technically permissible cathodic and anodic current densities as well as low voltages, as much with metallic parts as with plastics parts - and make it possible to secure qualitatively superior platings at extraordinarily high electroplating speeds.
As previously discussed at (5) above, the electrical field breaks down at the peripheral zones of the batch, and can only penetrate into them to a very limited extent. However the perforated end walls offer the advantage that the field can spread into the batch from two diametrically opposed sides (the two end walls) and in view of the short length of the barrel can work its way sufficiently deeply into the interior of the batch to be of some technical importance.
For this reason it is preferred that the length l of the barrel, measured parallel to its axis of rotation, should be less than half the diameter D of the barrel, measured normal to its axis of rotation. This further shortening of the length l intensifies the penetration of the batch by the electric field entering from both perforated end walls, and also promotes effective intermingling of the bulk parts during the rotational movement.
A further advantage of the tumbling barrel according to the invention is the effectiveness with which it intermingles the bulk parts, no matter whether these are made of metal or plastics. The free surface of the batch within the barrel is inclined in the direction of rotation (in the case of floating plastic parts roughly as shown by the straight line m--n in FIG. 2; and in the case of sinking metal or plastic parts in the inverted position) and therefore the individual bulk parts roll loosely, up or down as the case may be, along the line m--n or its inverted counterpart. The unusually large diameter of the barrel forces each part to roll a long way and thus enforces intensive intermingling of the parts.
Naturally it will be appreciated that bulk parts surrounded by the electrolyte behave like all bodies immersed in a liquid, i.e. they are acted upon by an upwards buoyancy force equal to the weight of the electrolyte they displace and also by a counteracting downwards gravitational force. The unusually large diameter of the barrel according to the invention, approximately twice that of the comparable conventional barrels, means that with similar proportionate filling-amounts - for instance two-thirds of the volumes of the barrels - the bulk parts pile up above one another about twice as high as in the conventional barrels. Whether it is the buoyancy force or the gravitational force which is predominant, thus whether the bulk parts stacked vertically above one another are seeking to float or to sink, it must follow that the higher is the "pile" of bulk parts the larger will be the resulting average contact pressure within the batch. Consequently, taking an actual case, if the diameter of the barrel according to the invention is twice as large as that of a known one of comparable volume and if these two barrels are for instance each filled with bulk parts to two-thirds of their volume, then the average batch amount - and consequently the mean specific contact pressure between the plastic parts - is approximately twice as large in the barrel according to the invention as in the known one, no matter whether the bulk parts in question are such as float or sink. This illustrates the fact that the barrel according to the invention achieves high contact pressures between the individual batch parts during the electroplating of plastics parts, which is one of the decisive functional requirements needed to avoid the defects previously discussed at (a), (b), (c) and (d).
The end walls are of large extent and for mechanical strength need to be substantially thicker than need be the barrel casing usually some five to six times stronger. On the other hand, the perforations in the end walls are generally directed horizontally, and of course fill with electrolyte when the barrel is immersed in the bath. In order to prevent too much electrolyte from being dragged out of the bath when the barrel is removed, the length of the perforation holes proper should be kept fairly short. A value of 12 mm. might be set as the maximum desired length for the perforations. This imposes a maximum thickness on the end walls, or at least on those regions thereof which contain the perforation holes proper. It will be recognized that this arrangement precludes large losses of electrolyte by drag-out when changing the barrel from one bath to the next and also helps minimize contamination of the electrolyte(s) and/or other treatment solutions.
The inner tube often can conveniently consist of an electrically non-conductive material, and in this case is preferably hollow and mostly provided with perforations. The electrical field established between the cathodically-connected batch and the rows of anodes can then pass through the hollow perforated inner tube and thus penetrate the peripheral zone of the batch adjacent this inner tube. Perforating the hollow inner tube consequently increases the size of the active peripheral areas of the batch, and thus increases the electroplating output of the barrel.
When the bulk parts to be electroplated, no matter whether made of metals or of plastics, have a specific weight very different from that of the electrolyte, and thus are either very buoyant or just the reverse, then it is usually advantageous to form the inner tube as a cathodic contact element. The same also applies when the individual bulk parts have relatively large dimensions, and it is therefore desirable to keep the annular space between the barrel casing and the inner tube free from any kind of obstruction (thus free too from other cathodic contact elements) in order not to interfere with the intermingling process.
However, when the bulk parts to be electroplated have a specific weight closely similar to that of the electrolyte, and thus have no strong tendency either to float up or to sink down, it is then usually advantageous to arrange an annular or part-annular cathodic contact element within the annular space between the peripheral barrel casing and the inner tube (here, like the outer barrel casing made of an electrically non-conductive material) and conveniently this should be arranged mid-way therebetween and concentrically therewith. This annular or part-annular cathodic contact element, which no matter whether closed or open can for convenience be called a contact ring, may be arranged either to rotate with the barrel or to remain stationary.
It will of course be recognized that it is possible to form the inner tube of electrically-conductive material, thus to use it as a cathodic contact element, and also to provide additional cathodic contact elements (for instance closed or open contact rings) in the inner space of the barrel as well.
The incorporation of a closed or open annular contact ring into the tumbling barrel of this invention helps to achieve, in conjunction with the other features herein described, most or all of the following desirable objectives in the electroplating of bulk parts made of plastics, namely so far as possible:
the greatest possible extent of the surface of the batch exposed to plating;
the distribution as evenly as possible of the maximum permissible cathodic current densities over virtually the whole batch surface;
the location within the batch of cathodic contact elements having the largest possible surfaces;
the establishment of the shortest possible paths for the electro-plating current within the batch from its peripheral zones to the cathodic contact elements; and
the promotion of the highest possible contact pressures between the bulk parts themselves and between them and the cathodic elements.
The two end-walls will preferably have a smooth interior surface and thus the opening for loading and unloading the barrel is preferably located at the peripheral circumference of the barrel, thus in the barrel casing and therefore must always be closed during electroplating with a removable lid.
When the barrels according to this invention are likely to be used for electroplating plastics parts then they should generally be provided with two openings located on the peripheral casing of the barrel diametrically opposite one another. Experience with conventional barrels has shown that when lifted out of the bath of electrolyte individual plastics parts due to their slight weight when wetted with water tend to remain adhering loosely to the walls of the barrel and thus can delay quick, complete unloading of the batch. However, when the barrel according to the invention is provided with two openings it is possible to rotate one of them into its lowermost position, and to empty the bulk parts through it by introducing a jet of water through the upper, second opening.
Conventional tumbling barrels are usually rotated at about 8 revolutions per minute or perhaps more - but high speeds of revolution cause high relative speeds between neighbouring bulk parts, which has disadvantages. If the parts are made of plastics, then bipole effects may arise and consequently through partial anodic polarisation of the galvanic platings these may acquire rough and/or matt surfaces. If the batch consists of metallic parts such as screws, electronic constructional elements or other relatively delicate bulk parts, then relatively high speeds of rotation can lead to mechanical damage through percussive action. It is an advantage of the barrels according to the invention that their large diameter permits low speeds of revolution without detriment to the degree of batch-intermingling. Consequently it is preferred to operate the barrels according to the invention at rotational speeds of less than 8 revolutions per minute. Although some deviation of the rotational axis of the barrel from horizontal is of course permissible, it has been found that substantial deviations from the horizontal are unsuitable for achieving an intensive intermingling effect. Thus it is to be assumed that the axis of rotation of the barrel will be directed horizontally or almost horizontally.
The overall shape of the tumbling barrels according to this invention, owing to their small length and large diameter, is thus disc-shaped. This makes possible a further advantageous and important embodiment of the invention, in which two, three or even more of the barrels are mounted coaxially and parallel to one another in a row upon separate axes or preferably upon a common axis so that they rotate synchronously. The coacting barrel units thus formed may be termed "double" or "triple" barrels etc. as the case may be, and these multiple-barrel units represent a substantial advance as opposed to the known ones - such as for instance that described in U.S. Pat. No. 3,038,851 which discloses a complicated and thus expensive yet electrolytically rather ineffective design of "quadruple" barrel. The multiple-barrel units according to the invention would be used in conjunction with rows of anodes arranged between the individual barrels forming the unit, these additional rows of anodes being of course mounted parallel to the end-walls. It is of course clear that the individual barrels in such a multiple-barrel unit can be filled simultaneously with batches of various kind(s) and size(s) of bulk parts - and thus for instance in a double barrel unit one might simultaneously electroplate batches of bulk parts made on the one hand of metals and on the other hand of plastics.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be well understood it will now be further explained, though only by way of illustration, with reference to the accompanying drawings, in which:
FIG. 1 shows a longitudinal cross-section through one preferred embodiment of tumbling barrel according to the invention, which is particularly suitable for electroplating bulk parts made of plastics;
FIG. 2 shows a transverse cross-section through the embodiment of FIG. 1;
FIG. 3 shows a plan view of the embodiment of tumbling barrel shown in FIG. 1;
FIG. 4 shows a cross-sectional view of a perforated, disc-shaped insert (which is fastened in the end-walls of the barrel);
FIG. 5 shows an elevational view of the insert shown in FIG. 4 and taken on the line A--A in that Figure; and
FIG. 6 shows a plan view of a so-called triple-barrel unit according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIGS. 1-3, and especially FIG. 2, the tumbling barrel there shown contains a batch 1 of bulk parts which are made of plastics and float in the electrolyte. The individual bulk parts in the batch 1 will each, once in every revolution of the rotational movement of the barrel, roll upwards roughly along the line m--n, becoming thereby thoroughly intermingled with the other plastics parts. Although when the bulk parts are made of metal and thus sink in the electrolyte the position of the line m--n must be inverted about the barrel centre this does not affect the principle of operation; and all the tumbling barrels here described with reference to FIGS. 1-6 of the accompanying drawings may be used without alteration of construction or procedure for electroplating bulk parts made of plastics as well as of metals.
The barrel as a whole is generally indicated at 10, and while it may have a prismatic overall shape of polygonal cross-section it is here shown as a cylinder of circular cross-section, with a pair of spaced parallel end-walls 11, which are perforated. To enable the length of the horizontal perforations to be less than the overall thickness of the end-walls 11, the latter may as shown be furnished with large cylindrical holes, arranged honeycomb fashion, in which perforated disc-shaped inserts 12 are fastened.
FIGS. 4 and 5 show the most important details of such a disc-shaped insert 12, which has a reinforced circular rim and whose face is curved so that it is concave towards the interior of the barrel 10, in order to accommodate any mechanical pressure exerted by the batch 1 against the insert and to transmit it by elastic deformation to the end-wall 11. It may be noted that these perforated, disc-shaped inserts 12 can generally best be made by injection moulding from some electrically non-conductive material; and they may be secured in the large cylindrical holes in the end-walls 11 by mechanical pressure, by welding or sticking, or possibly in some other interchangeable manner. Of course, the large cylindrical holes in the end-walls 11 can be covered over in other ways, for instance by an extruded grid made of plastics wires.
Between the end-walls 11 there extends an outer peripheral barrel casing 13, fixedly connected at each end to the end-walls 11, formed of some electrically non-conductive material, and provided with perforations.
The letter l in FIG. 1 indicates the length of the tumbling barrel, measured parallel to the axis of rotational symmetry, while the letter D in FIG. 2 indicates the diameter of the barrel, measured normal to that axis. In accordance with this invention the length l must always be smaller than the diameter D; but it is especially advantageous when the length l of the barrel is less than half its diameter D, as shown in FIGS. 1, 3 and 6.
In FIGS. 1 and 3, circular perforations in the barrel casing 13 are indicated by groups of small circles identified with the reference numeral 2, while in FIGS. 2 and 4 perforations of square cross-section in the end-walls 11 are indicated by square hatching identified with the reference numeral 3, as too are the square perforations in the barrel casing 13 of FIG. 6.
The barrel casing 13 is equipped with one or more openings 14 in order to permit the barrel 10 to be loaded with the batch 1 or unloaded again. These openings 14 are closed during electroplating with removable lids 15, which are perforated and are often conveniently secured to the barrel casing 13 with elastically sprung strips 16 made for instance of titanium. In the embodiment of FIGS. 1-3 the barrel 10 is equipped with two diametrically-opposite openings 14, in order to facilitate and accelerate the unloading procedure for the batch 1.
The circumference of one of the two end-walls 11 is formed as a gear-wheel 17 which is driven via the driving cog 4 from a motorised drive and motor source (not shown) thus rotating the entire barrel.
The end-walls 11, the barrel casing 13 and the lids 15 are made of electrically non-conductive materials which are chemically stable in the various electrolytes or other treatment solutions to be employed.
As shown in FIGS. 1, 2, 3 and 6, besides the tumbling drum the installation includes two different sets of anodes, firstly a row of anodes 5 parallel to the end-walls 11 and secondly a row of anodes 6 parallel to the axis of rotation of the barrel 10. The four rows of anodes 5 and 6 surround the barrel 10 on all sides in the horizontal plane.
The perforated inner tube 18 as shown in FIGS. 1 and 2 preferably consists of an electrically non-conductive material and is arranged coaxially within the barrel casing 13, extending from one end-wall 11 to the opposite one. The diameter of the cylinder 18 is indicated by the letter d. As shown, this inner tube 18 is mounted to rotate synchronously with the end-walls 11 and the barrel casing 13, but it can also be fixedly mounted so that it does not rotate with the barrel 10. As can be seen from FIG. 2, the ratio of the diameter d of the inner tube to the diameter D of the outer tube is of the order of one-third.
Although they should be smooth in the sense of free from obstructions, the inner surfaces of the end-walls 11, of the casing 13 and of the inner tube 18 can all advantageously be profiled (i.e. shaped unevenly in some manner, for instance with a pyramidal or corrugated screen pattern) in order to prevent the bulk parts from readily adhering when wet to these surfaces.
As can best be seen from FIG. 2, a cathode-contact 19 is located within the barrel casing 13, which transfers the electroplating current to the batch 1. This generally annular open-ring contact 19 is in fact a sort of double crescent shape, and has a large contact surface. The contact ring 19 can be mounted either so that it rotates synchronously with the barrel 10 or stationarily so that it does not. The contact ring 19 preferably forms a complete ring concentrically fastened between the casing 13 and inner tube 18. The supporting legs 20 of the cathode element 19 are insulated against the electrolyte and the electrical field by means of a chemically-stable, electrically non-conductive sheath 21.
In FIGS. 1, 2 and 3 the barrel 10 is supported by a carrying arm 22 whose end is bent at right angles to form a horizontal stub axle. The disc-shaped and tubular constructional elements 24 and 25 are fastened to the two supporting legs 20 with screw connections 23, and these elements are made of a plastics material suitable for an axle bearing upon which the barrel 10 (consisting of the two end-walls 11, the casing 13, the two lids 15 and the inner tube 18) can rotate. The contact ring 19, the supporting legs 20 and the bent carrying arm 22 form a seamless, continuous, rigid metallic body, which serves the dual function of mechanically supporting the barrel and enabling it to be lifted in and out of the electrolyte, as well as conducting the electroplating current. The carrying arm 22 is also protected by insulation 21, and helps to establish the connection between the direct current source and the negative pole.
It is possible, within the scope of the invention, to use the inner tube 18 as a cathodic contact element. The tube 18 is then made of a conductive material and forms a so-called cylinder-contact which transfers the electroplating current to the batch 1. The metallic cylinder 18 can then be supported, for instance, on the two supporting legs 20; and must then be chemically and electrically insulated against the electrolyte by means of sheath 21.
FIG. 2 shows a floating batch 1, which fills the inner space of the barrel approximately two-thirds full and completely (on all sides) covers the inner tube 18. The batch 1 is of optimum size when the tube 18 is just covered by the bulk parts 1 and sufficient room remains unoccupied for the intermingling procedure to take place freely. During rotation of the barrel the bulk parts 1 roll over the tube 18 (along the line m--n) and intermingle excellently.
FIG. 6 shows a multiple-barrel unit according to the invention in which three parallel-mounted barrels rotate about a common axis. The individual barrel casings 13 (and lids 15) consist of plastics sheets 27, having at their ends offset inter-engaging lugs joined and held together with bolts. The sheets 27, which are conveniently made by injection moulding, say from polypropylene, and are therefore interchangeable cheaply, are here provided with square perforations 3. The lid 15 is likewise formed from two such sheets 27, and is removably secured to the barrel casing 13 by means of a flexible closure 16 made of springy titanium strip.
If the barrel is to be used for larger metal parts and for plastics parts of higher mean specific weight, then its diameter can advantageously be very large, for instance D = 600 mm. while its length might then be l = 150 mm.
The electroplating current flows to the batch 1 from the direct current source via the insulated cable 29.
The end-walls 11 are provided with bearing bushes which rotate on the common axis of the triple-barrel unit of FIG. 6. At its ends this common axis is supported by two vertically arranged carrying arms 32, formed of titanium tubes of square or rectangular cross-section. The gear wheel is attached only to the barrel 10 mounted adjacent the cog 4; but the rotational movement imparted to the first barrel 10 by means of the gear wheel 17 is transferred to the other two barrels 10 of the triple-barrel unit by the couplings 34.
The support arms 32 (or the barrel-carrying arm 22 of FIG. 1) are each rigidly fixed to a support frame 33 which, together with the barrel(s) 10, forms a transportation unit - for instance a triple-barrel unit. The frame 33 is provided with appropriate mechanical and electrical fittings 35 to enable it to be placed upon the projecting rims of the electrolyte baths 7 and to be connected up to the direct current source when the barrel 10 is thus immersed in the electrolyte.
While the barrel according to the invention has been specially designed for electroplating it is in fact also suitable and indeed advantageous when used for etching and for electrolessly metal-coating batches of plastics parts and also for so-called anodically polishing of metallic parts in bulk.
If the barrel 10 is used for etching, for electroless metal-coating and for subsequent electroplating of batches 1 made of plastics, then the individual treatment steps of etching, of electroless metal-coating and finally electroplating the batch 1 (in that order) can be carried out in one and the same barrel 10. It is therefore unnecessary on conclusion of electroless metal-coating to reload the batch 1 from one barrel which is suitable only for etching and electroless metal-coating into another barrel which is suitable only for carrying out electro-plating.
Although as so far described the tumbling barrel of this invention is not so provided, there is no reason why either a soluble or an insoluble inner anode should not be mounted within the inner tube 18 when this is as preferred perforated and formed of an electrically non-conductive material.
If the barrel 10 is used for anodically polishing metallic bulk parts, then pole-reversal takes place at the batch 1, the contact element 19 and the electrodes 5 and 6. This means that the batch 1 together with the now anodic contact element 19 form the positive pole, while the formerly anodic electrodes 5 and 6 in the bath 7 now form the cathodes, thus the negative pole of the system. If there was an inner anode, this must now be converted to an inner cathode. This clearly is an improvement over the practices of the prior art as evidenced for instance by Austrian Pat. No. 222,454.
It will be noted that the barrel 10 is immersed in an electrolyte or other treatment solution which is contained in the bath 7. The horizontal line in the upper region of the baths 7 in FIGS. 1 and 2 symbolises the height of this liquid level.
It should also here be noted that the circular and square perforations 2 and 3 should be grouped together as densely as reasonably possible, in order to form as large an open "entrance" in the end-walls 11, in the casing 13 and in the lid 15 as possible, because a large entrance area, say of more than 15% of the whole barrel surface, permits high electroplating currents to enter the barrel and helps to maintain an even current distribution in the peripheral zones of the batch 1.
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An electroplating barrel for immersion in an electroplating electrolyte or other treatment liquid and for tumbling therein a bulk-mass of small parts, made of either electrolessly metal-coated plastics (synthetic resins) or of metals. The tumbling barrel consists essentially of a pair of spaced end walls, an annular treatment chamber defined by inner and outer peripheral walls between the end walls, and cathodic contacts, the length of the barrel being significantly less than the average overall diameter thereof.
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The invention concerns damping of changes in magnetic flux which occur in electric motors, thereby damping noise and vibration which the flux changes induce.
BACKGROUND OF THE INVENTION
FIGS. 1-5 provide simplified illustration of some events which occur in electric motors, and give some possible explanations of vibration and noise.
FIG. 1A illustrates permanent magnets 3 , having poles north N and south S, as contained within a permanent magnet electric motor (motor is not shown). FIG. 1B illustrates an armature 6 , which includes a single-turn coil 9 and a commutator 12 . In operation, brushes 15 contact the commutator 12 . FIG. 1C illustrates the components of FIGS. 1A and 1B when assembled.
FIG. 2A illustrates magnetic field lines 18 produced by the magnets 3 of FIG. 1 A. FIG. 2B illustrates current 21 induced by voltage V+ applied to the brushes 15 , and also the magnetic flux lines 24 which accompany the current 21 . FIG. 2C is a cross-sectional view of FIGS. 2A and 2B, with some of the flux lines 24 removed, and with the brushes 15 shown in contact with the commutator 12 .
FIGS. 3A through 3F show the components of FIG. 2C in assembled form, and show how the magnetic flux 24 , produced by the armature 6 , rotates as the armature 6 rotates. In FIG. 3A, the flux 24 is directed to the left, and does not cross the south pole S. (In actual practice, some leakage flux may cross the south pole, but FIG. 3A is a simplification, used to illustrate major principles.)
In FIG. 3B, the armature 6 has rotated clockwise, and the armature's flux 24 occupies the position shown. In FIG. 3C, the armature flux 24 penetrates the south pole S.
In FIG. 3D, the armature flux 24 has disappeared, because the commutator 12 is no longer in contact with the brushes 15 . In FIG. 3E, the armature flux 24 has re-appeared, because the commutator re-contacts the brushes 15 . However, the flux 24 has reversed in direction, as indicated by a comparison of FIG. 3E with FIG. 3 C. FIG. 3F indicates the position of the armature flux 24 a time later than in FIG. 3E, wherein the flux does not penetrate the north pole N.
The sequence of FIG. 3 provides a simple explanation of one cause of vibration. The sequence of FIGS. 3B through 3F show the following events:
Figure
Event
3B
No penetration of south pole.
3C
Penetration.
3D
No penetration.
3E
Penetration, but reversed in
direction.
3F
No penetration.
The sequence can be characterized as a repeated sequence of two events: flux penetration of the south pole S, followed by removal of penetration.
In effect, a magnetic field is repeatedly applied, and then removed, from the south pole S. The application of the magnetic field applies a force to the south pole S. The removal of the magnetic field removes the force. The sequence of
. . . force . . . no force . . . force . . . no force
is believed to cause vibration of the south pole S. Similar events occur with respect to the north pole N.
A second cause of vibration can be explained with reference to FIGS. 4 and 5. In FIG. 4A, an actual armature 6 comprises a rotor 30 containing slots 33 , which hold conductive bars 36 (also called armature windings). Additional conductors, indicated by the dashed lines 39 , form a conductive loop, analogous to loop 9 in FIG. 1 B.
FIG. 4B shows the slotted rotor 30 in cross section, and includes the conductive bars 36 . When current passes through the loop comprising bars 36 and dashed lines 39 in FIG. 4A, the flux lines 40 shown in FIG. 5A are generated. Two positions which the slotted rotor occupies during rotation are shown in FIGS. 5B and 5C.
A significant feature of these two positions is that the flux lines must traverse different numbers of slots en route to the south pole S. That is, different flux lines follow paths through different materials. Consequently, different flux lines apply different forces to the south pole S. These differences can also cause vibration, as will now be explained.
The slots 33 in FIG. 5A act as an air gap, and reduce the strength of the flux lines 40 . (Even though the slots 33 contain the conductive bars 36 , the slots can be viewed, for present purposes, as being filled with air, because the magnetic permeability of the conductive bars is close to that of air, when compared with the permeability of the material of which the rotor 30 is itself constructed.
How an air-gap can change a magnetic field can be explained by an analogy. When a hand-held magnet is brought two inches from a steel nail, the nail hardly “feels” the magnet, because of the large, two-inch, air gap. However, when the magnet is brought sufficiently close to the nail, the nail snaps into contact with the magnet. The very small air gap, created when the magnet approached the nail, caused the strength of the flux lines (more precisely, the magnetic flux density) to increase.
Similarly, when the rotor 30 is in the position shown in FIG. 5B, the flux lines must pass through three slots, or air gaps, indicated in insert I, en route to the south pole S. In contrast, in FIG. 5C, the number of slots increases from three to four, as indicated in insert I 2 .
In effect, the air gap between the armature and the south pole S has increased from FIG. 5B to FIG. 5 C. Consequently, the “pull” which the rotor 30 applies to the south pole S, because of the flux lines 40 , decreases in FIG. C, compared with FIG. 5B, because of the increased air gap, similar to the case of the steel nail.
Therefore, as the armature 30 rotates, the number of slots, through which the flux lines must travel en route to the south pole S, changes, thereby changing the magnetic force applied to the south pole S. This changing magnetic force induces vibration. Some components of the vibration lie within the range of human hearing, and are perceived as audible noise.
A similar analysis applies to the north pole N.
SUMMARY OF THE INVENTION
An object of the invention is to reduce noise and vibration in electric motors.
A further object of the invention is to reduce noise and vibration caused by a changing magnetic flux applied to internal components of a permanent magnet electric motor.
In one form of the invention, a conductive ring surrounds a stationary pole of a magnet in an electric motor. When armature flux through the hole in the ring changes, a current is induced, which generates a magnetic field which compensates for the change in the armature flux, thereby tending to keep the overall flux constant.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-1C illustrate exploded views of a simplified DC machine.
FIGS. 2A-2C illustrate the components of FIG. 1, in greater detail.
FIGS. 3A-3F illustrate rotation of magnetic flux line 24 , caused by rotation of coil 9 of FIG. 1B
FIG. 4A is an exploded view of a slotted rotor.
FIG. 4B is a cross-sectional view of a slotted rotor contained between two magnets.
FIGS. 5A-5C illustrate how the air gap effectively changes between a rotor and stator, during rotation of the rotor.
FIG. 6 illustrates one form of the invention.
FIGS. 7A-7E illustrate rotation of magnetic flux lines 59 , with respect to ring 50 of FIG. 6 .
FIG. 8 illustrates another form of the invention.
FIG. 9 illustrates a perspective view of part of the apparatus of FIG. 8 .
FIG. 10 is a plot of search coil voltage versus time, when the motor of FIG. 8 was run at no load, with rings 50 and 53 effectively absent.
FIG. 11 is a plot of search coil voltage versus time, when the motor of FIG. 8 was run at no load, with rings 50 and 53 in FIG. 6 present.
FIG. 12 illustrates a plot of accelerometer output versus frequency.
FIG. 13 is a plot of motor performance, with rings present, and with rings absent.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 6 illustrates an electric motor comprising one form of the invention. For ease of illustration, no armature coils are shown. In this embodiment, the electric motor comprises two stationary conductive loops 50 and 53 . The loop 50 interacts primarily with the flux penetrating the south pole S, and the other loop 53 interacts primarily with the flux penetrating the south pole S.
FIG. 7 provides a simplified explanation of he operation of loop 50 . In FIG. 7A, loop 9 , shown also in FIG. 1B, produces magnetic flux lines 59 . In the sequence of FIGS. 7B through 7E, the loop 9 is shown rotating about motor axis 61 . The flux lines 59 rotate also, as indicated.
During the rotation, the flux, which the ring 50 in FIG. 7A surrounds, changes, as indicated by FIGS. 7B through 7E. This change induces a current 65 in FIG. 7 A. By Lenz's Law, this current produces its own flux (not shown) which compensates for the changing flux, thereby tending to keep the overall flux passing through the ring 50 constant.
More specifically, a voltage is induced in the ring, which is proportional to the first time-derivative of the normal (i.e., perpendicular) component of the flux passing through the ring. This voltage induces the current 65 in FIG. 7 A. One normal component N is shown in FIG. 7 C. Normalcy, or perpendicularity, is defined with reference to the plane of the ring 50 .
Therefore, the ring 50 in FIG. 6 shields the south pole S from the changes in flux discussed in the Background of the Invention.
FIG. 8 illustrates apparatus used in a test undertaken by the Inventors. The upper part of the Figure is a diagram of electrical continuity. Corresponding parts, similarly labeled, are shown in FIG. 9 . The combination of the rods R in FIGS. 8 and 9, together with end plates E, form the conductive ring of FIG. 6 .
Specifically, in FIG. 8, rods R 1 , R 2 , and the end plates E (not shown in FIG. 8, but visible in FIG. 9) form a ring analogous to ring 50 in FIG. 6 . Also, in FIG. 8, rods R 3 , R 4 , and the end plate E (not shown in FIG. 8, but visible in FIG. 9) form a ring analogous to ring 53 in FIG. 6 . The two coils, analogous to coils 50 and 53 in FIG. 6, are held at a common DC potential, by virtue of the connection through end plate E, indicated as a thin hoop in FIG. 8 .
In the test, an accelerometer 70 , shown at the bottom of FIG. 8, was attached to a casing T to which magnet pole S was attached. A search coil 78 , was used to detect induced voltage in the ring comprised of R 1 , R 2 and the two end plates E, shown in FIG. 9 . The search coil 78 infers flux changes in the magnetic field passing between rods R 1 and R 2 in FIG. 8 .
FIG. 9 illustrates an exploded perspective view of part of the apparatus of FIG. 8 .
FIG. 10 is a plot of search coil voltage versus time, when the motor of FIG. 8 was run at no load, with no dampers present (the coils 50 and 53 were open-circuited, or, from another viewpoint, each ring was split open). FIG. 11 is a plot of search coil voltage versus time, when the motor of FIG. 8 was run at no load, with rings 50 and 53 in FIG. 6 present, as indicated in FIG. 8 (the rings 50 and 53 were not split, but present in ring-form).
The difference in the two plots indicates that the rings, or dampers, reduced the search coil voltage, thereby supporting the inference that flux changes through the rings 50 and 53 were reduced by the rings.
FIG. 12 illustrates a plot of accelerometer output versus frequency. The solid line indicates the damped case, and is, in general, smaller in amplitude at most frequencies than the dashed line, which indicates the undamped case. FIG. 12 supports the inference that the damping rings 50 and 53 in FIG. 6 reduce vibration of the motor.
FIG. 13 indicates that the presence of the dampers does not significantly affect motor performance.
It should be observed that the magnets N and S in FIG. 6 need not be permanent magnets, but can take the form of electromagnets.
It should be appreciated that the rings 50 and 53 are electrically independent of the motor, with the exception of the current 65 , shown in FIG. 7A, which is induced. That is, neither stator nor rotor current passes through the rings 50 and 53 .
Notice that one effect of ring 50 in FIG. 6 can be characterized as reducing interaction between (a) the time changing flux 59 in FIG. 7 and (b) the magnet pole S in FIG. 6, by virtue of reducing the magnitude of changes in the flux which reach the pole S.
As FIG. 9 indicates, the components used to construct the rings can also be used as part of the motor's structural housing. For example, rods R may provide support for end rings E.
In FIG. 9, the end rings E are electrically part of the rings of the type shown in FIG. 6 . However, in FIG. 9, the end rings E are not part of the case structure, which includes tube T, although they could be so constructed.
Numerous substitutions and modifications can be undertaken without departing from the true spirit and scope of the invention. What is desired to be secured by Letters Patent is the invention as defined in the following claims.
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In an electric motor, a conductive ring surrounds, and shields, each pole of stationary magnet. When a changing magnetic flux, produced by an armature, penetrates the ring, by Lenz's Law, the changing flux causes the ring to produce a counter-flux, which adds to the changing flux. Consequently, the total flux within the ring tends to remain constant. Maintaining this constant flux tends to reduce noise and vibration which the changing rotor flux otherwise causes.
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PRIORITY
[0001] This application is a Divisional of the Continuation application filed by Huang, et al. on Jan. 24, 2003 entitled Chinese Traditional Medicines for Psoriasis with application Ser. No. 10/350, 408 which was a Continuation of the utility application filed by Huang, et al on Jan. 14, 2002 entitled Chinese Traditional Medicines for Psoriasis with application Ser. No. 10/050,060.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention. The present invention generally relates to disclose some Chinese formula for psoriasis. Whether treatment for psoriasis is targeted at both the hyperproliferative and inflammatory aspect of the topical therapy.
[0003] Psoriasis is a widespread, inflammatory and scaling skin disease, which is characterized by abnormal keratinocyte proliferation and differentiation of the epidermis, accumulation of polymorphonuclear leukocytes in the skin. Dominant and interdependent features of psoriasis are epidermal hyperproliferation, disturbed keratinocyte differentiation, and inflammation of the dermis and epidermis.
[0004] However, the etiology of this very distressing skin disorder is unknown. The treatment for psoriasis is targeted at both the hyperproliferative and inflammatory aspect of the topical therapy. Müller K, et al., J Med Chem. 39, 3132-8,1996 has reported some dihydroxy-9(10H)-anthracenones that have inhibited keratinocyte growth, 5-lipoxygenase, and the formation.
[0005] Current treatment for psoriasis may be topical or systemic. Müller K., Curr. Pharm. Design, 6, 901-18, 2000 has reported indications for systemic treatment are failure to respond to topical treatment and severe or life-treatening forms of psoriasis.
[0006] Müller K and Huang H S., Chin Pharm J. 48, 337-54, 1996 have suggested the biological activity of drugs useful as antipsoriatic agents may be evaluated by their antiproliferative activity in cell cultures and antioxidative activity in vitro, since there is no appropriate animal model of psoriasis.
[0007] CTMs (Chinese traditional medicines) have been extensively used to treat psoriasis and have acquired considerable favor among many of the patients. The earliest description of psoriasis in ancient Chinese medical literature may be found in Sui-Dynasty, 581-618 AD. According to Chinese literatures, “Bian Zheng Shi Zhi”, Lin X R. J. Dermato. 20, 746-55, 1993 collected a number of clinical psoriasis cases report, and distinguished psoriasis into 2 or 3 types, namely “Blood-Heat” type and “Blood deficiency-Dryness” type or “Blood-Heat,” “Blood deficiency-Dryness” and “Blood stasis” type. While in also described prescription (I) to treat “Blood-Heat” type, that including Caulis Spatholobi 2, Radix Rehmanniae Exsiccata 6, Radix Lithospermi 13, Radix Salviae Miltiorrhizae 14, Radix Paeoniae Veitchii 17, Rhizoma Imperatae 23, and Flos Sophorae 27. Prescription (II) to treat “Blood deficiency-Dryness” type that including Caulis Spatholobi 2, Radix Angelicae Sinensis 3, Rhizoma Smilacis Glabrae 4, Radix Rehmanniae Exsiccata 6, Radix Ophiopogonis Japonici 7, Radix Asparagi 8, Nidus Vaspae 10, and Radix Salviae Miltiorrhizae 14. Prescription (III) to treat “Blood stasis” type that including Canlis Spatholob 2, Rhizoma Sparganii 5, Herba Hedyotis 11, Rhizoma Curcumae Aeruginosae 15, Pericarpium Citri Reticulatae 18, Flos Carthami 19, Semen Amygdalus Persicae 20, and Ramulus Euonymi 26.
[0008] It is well know that CTMs are compound medicines, which are combined with various crude drugs, and the exhibition of their pharmacologic activity is the result of the pharmacodynamic interaction of the combined drugs and their components. Zhonghua Bencao have state Radix Tripterygiim Wilfordii 1 is the plant of Tripterygium wilfordii Hook. f., have containing some alkaloids, diterpene, triterpene ingredients, such as Wilfordine, Tripterin, Triptolide, Tripdiolide, Triptonide, Celastrol, Tripterifordin, Triptofordin A-G, Triptogelin A 1-4 , Triptogelin B 1 , Triptogelin C 1 and C 4 , Triptogelin D 1-2 , Triptogelin E 1-4 , Triptogelin G 1 , Triptoquinone A-G, Triptonoterpen, Neotriptonodiol, Triptonodiol, Neotriptonolide.
[0009] Caulis Spatholobi 2 is the plant of Spatholobus suberectus Dunn have containing some Fridelan-3β-ol, daucosterol, β-sitosterol, 7-oxo-β-sitosterol, formononetin, ononin, prunetin, 9-methoxycoumestrol, medicago, afromosin, 7-dihydroxy-6-methoxy-dihydroflavonol, chalcone, protocatechuic acid, epicatechin, licochalcone A, isoliquiritigenin, 5α-stigmastane-3β,6α-diol, 2′,4′,3,4-tetrahydroxy daidzein, stigmast-5-ene-3β,7α-diol, cajanin.
[0010] Radix Angelicae Sinensis 3 is the plant of Angelicae sinensis (Oliv.) Diels have containing essential oil, nicotinic acid, butylidene phthalide, n-Valerophonone-O-carboxylic acid, carvacrol, phenol, ocresol, p-cresol, guaiacol, 2,3-dimethylphenol p-ethylphenol, isoeugenol, m-ethylphenol, 4-ethylresorcinol, 2,4-dihydroxy-acetophenone, vanillin, ligustilide, adenine, myrcene, α-pinene, β-ocimine-X, alloocimine, bicycloelemene, cadinene, 6-n-butyl-1,4-cycloheptdiene, 2-methyldodecan-5-one, copaene, 1,5-trimethyl-2-formyl cyclohexa-2,5-diene-4-one, acoradiene, uracil, acetophenoneβ-bisabolene, isoacoradiene, bergamotene, brefeldin, eucarvonel, threonine, senkyunolide, 3,4-dimethyl-benzaldehyde, trans-β-farnesene, γ-elemene, n-butylphthalide, n-butylidenephthalide, safrole, leucine, camphoric acid, azelaic acid, sebacic acid, myristic acid, phthalic 6-methoxy-7-hydroxycoumarin, anhydride, α-cedrene, vanillic acid, p-ethyl-benzaldehyde, verbenone, 2,4,6-trimethyl benzaldehyde, angelicide, β-selinene, 1-tetradecanol, β-sitosterol, daucosterol, palmitic acid, succinic acid. ferulic acid, cuparene.
[0011] Rhizoma Smilacis Glabrae 4 is the plant of Smilax glabra Roxb. have containing tannin, saponin, resin, astilbin, engeletin, 3-O-caffeoylshikimic acid, shikimic acid, ferulic acid, β-sitosterol, quercetin, kaempferol.
[0012] Rhizoma Sparganii 5 is the plant of Sparganium stoloniferum Buch.-Ham. have containing benzeneethanol, dehydrocostuslactone, hexadecanoic acid, 1,4-benzenediol, β-elemene, 2-furanmethanol, 2-acetylpyrrole, stigmasterol, 1-hydroxy-2-acetyl-4-methylbenzene, 9-octadecenoic acid, 3-phenyl-2-propenoic acid, formonetin, β-sitosterol, 11-eicosenoic acid, decanedioic acid, benzoic acid, azelaic acid, 3,4-dihydro-8-hydroxy-3-methyl-1H-2-benzopyran-4-one, daucosterol, succinic acid, sanleng acid, 9,11-octadecadienoic acid, 9,12-octadecadienoic acid, 9-hexadecenoic acid, 19-nonadecenoic acid.
[0013] Radix Rehmanniae Exsiccata 6 is the plant of Rehmannia glutinosa (Gaertn.) Libosch. Ex Fisch. et Mey. have containing Leonuride, rehmannoside A-D, ajugol, aucubin, melittoside, rehmaglutin A-D, acteoside, isoacteoside, monometittosid, geniposide, ajugoside, 6-O-E-feruloylajugol, jioglutin D-E, jioglutoside A, jioglutolide, 6,8-dihydroxyboschnialactone, echinacoside, cataepolgenin, grardoside, Mioporosidegenin, rehmaionoside A-C, rehmapicroside, purpureaside C, Jionoside A1, Jionoside B1, cistanoside A, cistanoside F, glutinoside, some acid.
[0014] Radix Ophiopogonis Japonici 7 is the plant of Ophiopogon japonicus (L. f.) Ker-Gawl have containing linalool, ruscogenin, ophiopogonin B, ophiopogonin D, jasmololone, (23S, 24S, 25S)-23,24-dihydroxyruscogenin, methylophiopogonanone A-B, ophiopogone A, ruscogenin-1-O-sulfate, terpinen-4-ol, glycerol, longifolene, cyperene, guaiol.
[0015] Radix Asparagi 8 is the plant of Asparagus cochinchinensis (Lour.) Merr. have containing methylprotodioscin, pseudoprotodioscin, yamogenin, diosgenin, sarsasapogenin, asparagus polysaccharide A-D, oligosaccharide I-VII, and smilagenin.
[0016] Olibanum 9 is the plant of Boswellia carterii Birdw have containing α,β-boswemc acid, olibanoresene, O-acetyl-β-boswellic acid, thujone, dihydroroburic acid, epilupeol acetate, tirucallol, pinene, Arabic acid, 5-hydroxy-p-menth-6-en-2-one, bassorin, myrtenic acid, limonene, 10-hydroxy-4-cadinen-3-one, myrtenal, phellandral, α,β-phellandrene, pinocamphone, carvotanacetone, cuminaldchyde, 1-acetyl-4-isopropenylcyclopentene, 3,6,6-trimethylnorpinan-2-one, nopinone, verbenone, α-amyrenone, isopropylidenecyclohexane, piperitone, cryptone, carvone, α-campholenaldehyde, p-menth-4-en-3-one, O-methylacetophenone, perilla-aldehyde, eucarvone, 2,4-dimethylacetophenone, γ-campholenaldehyde, 11-keto-α-amyrenone.
[0017] Nidus Vaspae 10 is the animal of Polistes mandarinus Saussure have containing resin, wax, saccharide.
[0018] Herba Hedyotis 11 is the plant of Hedyotis Diffusa Willd. have containing asperuloside, hentriacontane, asperulosidic acid, β-sitosterol, deacetylasperulosidic acid, scandoside, geniposidic acid, stigmasterol, 5-O-p-hydroxycinnamoyl scandoside methylester, ursolic acid, p-coumaric acid, β-sitosterol-β-D-glucoside, 2-methyl-3-hydroxy-4-methoxyanthraquinone, oleanolic acid, scandoside methylester, 2-methyl-3-hydroxyanthraquinone, 2-methyl-3-methoxyanthraquinone, 5-O-feruoyl scandoside methylester, 5-O-p-methoxy cinnamoyl scandoside methylester.
[0019] Indigo Naturalis 12 is the plant of Baphicacanthus cusia (Nees) Bremek., Polygonum tinctorium Ait., Indigofera tinctoria L., and Isatis indigotica Fort. have containing indirubin, indigo.
[0020] Radix Lithospermi 13 is the plant of Lithospermum erythrorhizon Sieb. et Zucc. have containing Shikonin, deoxyshikonin, 1-eicosanol, isovalerylshikonin, 1-tetracosanol, caffeic acid, isobutyrylshikonin, 1-docosanol, stearyl alcohol, α-methyl-n-butyrylshikonin, β,β-dimethylacrylshikonin, lithospermidin A, lithospermidin B, β-hydroxyisobutyrylshikonin.
[0021] Radix Salviae Miltiorrhizae 14 is the plant of Salviae miltiorrhiza Bge. have containing cryptotanshinone, diterpen, nortanshinone, tanshinone I, IIA-IIB, V-VI, stigmasterol, Isotanshinone I, IIA-IIB, neocryptotanshinone, Δ 1 -dehydrotanshinone IIA, isocryptotanshinone, 1-ketoisocryptotanshinone, hydroxytanshinone IIA, dihydrotanshinone, methyl tanshinonate, dihydroisotanshinone I, formyltanshinone, methylenedihydrotanshinone, 1,2,5,6-tetrahydrotanshinone I, β-sitosterol, methylene tanshiquinone, dihydrotanshinquinone, danshexinkum A-D, tanshindiol A-C, miltirone, Δ 1 -dehydromiltirone, 4-methylenemiltirone, miltionone I-II, salvilenone, tanshinlactone, dihydrotanshinlactone, ursolic acid, danshenspiroketallactone, epidanshenspiroketallactone, cryptoacetalide, epicryptoacetalide, salvinone, salviolone, miltiodiol, miltipolone, norsalvioxide, ferruginol, saiviol, sugiol, salvianic acid A-C, D(+)-β-(3,4-dihydroxyphenyl) lactic acid, salvianolic acid, rosmarinic acid, methyl rosmarinate, monomethyl lithospermate, dimethyl lithospermate, ethyl lithospermate, lithospermic acid B, protocate chualdehyde, isoferulic acid, baicalin, 5-(3-hydroxypropyl)-7-methoxy-2-(3′-methoxy − 4 / -hydroxy-phenyl)-3-benzo[b]furancarbaldehyde, daucosterol, tigogenin, isoimperatorin.
[0022] Rhizoma Curcumae Aeruginosae 15 is the plant of Curcumae aeruginosae Roxb. have containing essential oil, sesquiterpenoid such as, curzerenone, borneol, germacrone, pinene, curcumene, camphene, limonene, 1,8-cineole, turmerone, terpinene, isoborneol, caryophyllene, caryophyllene epoxide, curcurmenol, arturmerone, curdione, aerugidiol, difurocumenone, isocurcumenol, curcuminoids.
[0023] Myrrha 16 is the plant of Commiphora myrrha Engl. have containing heerabomyrrholic acid, commiphoric acid, commiphorinic acid, heerabomyrrhol, heeraboresene, commiferin, eugenol, m-cresol, pinene, limonene, cuminaldehyde, cinnamic aldehyde, heerabolene, 8α-methoxyfuranodiene, 8α-acetylfuranodiene, curzerene, lindestrene, furanoeudesma-1,3-diene, furanodiene, resin, gum.
[0024] Radix Paeoniae Veitchii 17 is the plant of Paeonia veitchii Lynch have containing paeoniflorin, benzoyl paeoniflorin.
[0025] Pericarpium Citri Reticulatae 18 is the plant of Citrus reticulata Blanco have containing carvacrol, α-farnesene, citronellal, (1,1-dimethylethy)-benzenemethanol, terpinolene, sabinene hydrate, 5,7,4′-trimethoxyflavone, ferulic acid, α-terpineol, decanal, 5,7,8,3′,4′-pentamethoxyflavone, 5,7,8,4′-tetramethoxyflavone, α-terpinene, 5-O-desmethylcitromitin, 5-hydroxy-7,8,4′-trimethoxyflavone, sinensetin, α-thujene, sabinene, 5,4′-dihydroxy-7,8-dimethoxyflavone, nobiletin, octanal, pinene, 4-terpineol, 5,6,7.3′,4′-pentamethoxyflavone, benzyl alcohol, citromitin, α-ocimene, p-cymene, 5,6,7,8,3′,4′-hexamethoxyflavone, perillaldehyde, xanthomicrol, limonin, limonene, 5-hydroxy-6,7,3′,4′-tetramethoxyflavone, neral, thymol, p-sitosterol, octanol, 5-hydroxy-6,7,8,3′,4′-pentamethoxyflavone, citronellol, α-phellandrene, β-myrcene, 5,7,4′-trihydroxy-6,8,3′-trimethoxyflavone, linalool, sudachiflavone, neohesperidin, 5-hydroxy-6,7,8,4′-tetramethoxyflavone, tangeritin, 3,7-dimethyl-7-octenal, nerol, 4′-hydroxy-5,6,7,8-tetramethoxyflavone, 5,5′-oxydimethylene-bis(2-furaldehyde), 5,6,7,8,4′-pentamethoxyflavone, γ-terpinene, 5,4′-dihydroxy-6,7,8-trimethoxyflavone, hesperidin.
[0026] Flos Carthami 19 is the plant of Carthamus tinctorius L. have containing carthamin, precarthamin, safflor yellow A-B, safflomin A, chlorogenic acid, caffeic acid, catechol, pyrocatechol, dopa, and volatility compounds.
[0027] Semen Amygdalus Persicae 20 is the plant of Amygdalus persica L. have containing citrostadienol, β-sitosterol, β-sitosterol-3-O-β-D-glucopyranoside, 7-dehydroavenasterol, 24-methylene cycloartanol, 3-feruloylquinic acid, β-sitosterol 3-O-β-D-(6-O-palmityl) glucopyranoside, campesterol-3-O-β-D-glucopyranoside, Chlorogenic acic, β-sitosterol-3-O-β-D-(6-O-oleyl)glucopyranoside, triolein, campesterol, tryptophane, campesterol-3-O-β-D-(6-O-oleyl)glucopyranoside, prunasin, campesterol-3-O-β-D-(6-O-palmityl) glucopyranoside, oleic acid, 3-caffeoxyquinic acid, methyl-α-D-fructofuranoside, methyl-β-D-glucopyranoside, lineleic acid, amygdalm.
[0028] Radix Angelicae Biserratae 21 is the plant of Angelicae biserrata ( Shan et Yuan ) Yuan et Shan, have containing columbianetin, columbianetin acetate, anpubesol, osthol, isoimperation bergapten, xanthotoxin, thymol, columbianadin, p-cymene, angelol D, columbianetin-β-D-glucopyranoside, pcresol, γ-aminobutyric acid, β-cedrene, oxocyclohexandecan-2-one, α-pinene, humulene, dodccylisopropylether, eremophilene, 4,4′-methylenebis(2,3,5,6-tetramethyl)phenol, nerolidol, α-cedrene, α-longipinene, sylvestrene, 3-methylnonane, aphelladrene.
[0029] Radix Angelicae Hangbaizhi, or Radix Angelicae Qibaizhi 22 is the plant of Angelicae dahuricae and some variation spp. (Umbelliferae) have containing some lactones, such as imperatorin, isoimperatorin, alloisoimperatorin, oxypeucedanin, isooxypeucedanin, oxypeucedanin hydrate, byakangelicin, byakangelicol, neobyakangelicol, pabulenol, sitosterol, phellopterin, xanthotoxol, bergapten, 5-methoxy-8-hydroxypsoralen, palmitic acid.
[0030] Rhizoma Imperatae 23 is the plant of Imperata cylindrical (L.) Beauv. var. major (Nees) C. E. Hubb. have containing arundoin, cylindrin, isoarborinol methyl ether, fernenol, isoarborinol, and arborinol methyl ether.
[0031] Herba Artemisiae Anomalae 24 is the plant of Artemisia anomala S. have containing arteanoflavone, coumarin, eupatilin, tricin, herniarin, scopoletin, simiarenol, umbelliferone, salvigenin, reynosin, armexifolin, anomalamide, palmitic acid, dehydromatricarin, deacetyldehydromatricarin, secotanapartholide A, cyclohexanehexol monomethyl-ethertanaphillin isomer, artanomaloide, arteanomalactone, aurantiamide acetate, anabellamide, trans-o-hydroxycinnamic acid, trans-o-hydroxy-p-methoxycinnamic acid.
[0032] Polyporus 25 is the plant of Polyporus umbellatus (Pers.) Fries have containing Polyporusterone A-G, ergosta-4,6,8(14),22-tetraen-3-one, 25-deoxymakisterone A, 25-deoxy-24(28)-dehydromakisterone A, ergosta-7,22-dien-3-one, ergosta-6,22-dien-3-ol, α-hydroxytetracosanoic acid, ergosta-5,7,22-trien-3-ol.
[0033] Ramulus Euonymi 26 is the plant of Euonymus alatus Sieb. have containing quercetin, dulcitol, frielin, and resin. Evonoloside, Evozine, Evonine, Evomonoside, Glucoevonoside, β-D-glu-Glucoevonoloside, Evorine.
[0034] Flos Sophorae 27 is the plant of Sophora japonica L. have containing azukisaponin I-II, V, soyasaponin I, III, kaikasaponin I-III, quercetin, β-sitosterol, octadecatrienoic acid, myristic acid, rutin, isorhamnetin, isorhamnetin-3-rutinoside, kaempferol-3-rutinoside, betulin, sophoradiol, lauric acid, dodecenoic acid, tetradecenoic acid, tetradecadienoic acid, palmitic acid, hexadecenoic acid, stearic acid, octadecadienoic acid, arachidic acid.
[0035] Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows 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.
SUMMARY OF THE INVENTION
[0036] The primary purpose of the invention is to disclose some Chinese formula for psoriasis. Whether treatment for psoriasis is targeted at both the hyperproliferative and inflammatory aspect of the topical therapy.
[0037] The second purpose of the invention is to disclose the manufacture method of dosage for psoriasis.
[0038] The purpose of the foregoing Abstract is to enable the United States Patent and Trademark Office and the public generally, and especially the scientists, engineers, and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection, the nature and essence of the technical disclosure of the application. The Abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
[0039] Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description wherein I have shown and described only the preferred embodiment of the invention, simply by way of illustration of the best mode contemplated by carrying out my invention. As will be realized, the invention is capable of modification in various obvious respects all without departing from the invention. Accordingly, the drawings and description of the preferred embodiment are to be regarded as illustrative in nature, and not as restrictive in nature.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] The invention will now be described by way of example with reference to the accompanying Tables and Figures in which:
[0041] Table 1 illustrates antiproliferative activity against HaCaT cells by CTMs.8
[0042] Table 2 illustrates the inhibitory effects a of various solvents extract of CTMs on LP of rat brain homogenate induced by FeCl 2 in vitro.
[0043] Table 3 illustrates the prooxidative efects a of various solvents extract of CTMs on LP of rat brain homogenate induced by FeCl 2 in vitro.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] While the invention is susceptible of various modifications and alternative constructions, certain illustrated embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific form disclosed, but, on the contrary, the invention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention as defined in the claims.
[0045] The role of oxygen radicals in human disease has become an area of intense interest. There are compilation cause and effect on oxidative tress, lipoproteins and cardiovascular dysfunction etc. Low concentrations of oxygen radicals are constantly formed as physiological byproducts in the human body, but they can be toxic when generated in excess. This toxicity can be of therapeutic interest, depending on the nature of the target cell.
[0046] Some of the primary targets of oxygen radicals are the lipids that constitute the cell membrane. Many reactive oxygen species (ROS) are more soluble in a lipid environment than in aqueous systems and can readily cross biological membranes. Although oxygen radicals are responsible for the inflammation of the no affected psoriatic skin, the same species are central to clinical efficacy of CTMs (Chinese traditional medicines). It is common in Western countries, affecting about 2% of the Caucasian population, affecting 1-3% of the American population, but is relatively uncommon in Asia, Lin X R. J. Dermato. 20, 746-55, 1993 have reported the prevalence rate of psoriasis in China was 1.23 ‰ in 1984. The true incidence may be even higher, because individuals with minor clinical manifestations may not seek medical attention, but elect to treat the condition themselves.
[0047] The invention elected many of CTMs (Chinese traditional medicines) for psoriasis that including Radix Tripterygiim Wilfordii 1, Caulis Spatholobi 2, Radix Angelicae Sinensis 3, Rhizoma Smilacis Glabrae 4, Rhizoma Sparganii 5, Radix Rehmanniae Exsiccata 6, Radix Ophiopogonis Japonici 7, Radix Asparagi 8, Olibanum 9, Nidus Vaspae 10, Herba Hedyotis 11, Indigo Naturalis 12, Radix Lithospermi 13, Radix Salviae Miltiorrhizae 14, Rhizoma Curcumae Aeruginosae 15, Myrrha 16, Radix Paeoniae Veitchii 17, Pericarpium Citri Reticulatae 18, Flos Carthami 19, Semen Amygdalus Persicae 20, Radix Angelicae Biserratae 21, Radix Angelicae Hangbaizhi, or Radix Angelicae Qibaizhi 22, Rhizoma Imperatae 23, Herba Artemisiae Anomalae 24, Polyporus 25, Ramulus Euonymi 26, Flos Sophorae 27.
[0048] Collect some of CTMs together as prescription (A) which is Caulis Spatholobi 2, Radix Rehmanniae Exsiccata 6, Radix Lithospermi 13, Radix Salviae Miltiorrhizae 14, Radix Paeoniae Veitchii 17, Rhizoma Imperatae 23, Flos Sophorae 27. Prescription (B) which is Caulis Spatholobi 2, Radix Angelicae Sinensis 3, Rhizoma Smilacis Glabrae 4, Radix Rehmanniae Exsiccata 6, Radix Ophiopogonis Japonici 7, Radix Asparagi 8, Nidus Vaspae 10, Radix Salviae Miltiorrhizae 14. Prescription (C) which is Caulis Spatholobi 2, Rhizoma Sparganii 5, Herba Hedyotis 11, Rhizoma Curcumae Aeruginosae 15, Pericarpium Citri Reticulatae 18, Flos Carthami 19, Semen Amygdalus Persicae 20, Ramulus Euonymi 26.
[0049] To make the solid type of the drugs including tablet, powder, capsule, and granule, the invention of CTMs (Chinese traditional medicines) extracts were added with various additives, such as magnesium stearate, corn powders, starch, lactose, fiber, ethanol, glycerin and so forth, diluent, lubricant, flavouring, disintegrants, binders, coloring agents, sweetener. To make liquid type of the drugs, phosphate buffer solution was added to adjust the pH. This invention was allowed to make the solid or liquid types of the drugs. In addition to the drugs administered by oral or rectal, the injection type or liquid type of effective dosage, non-intestinal injection type, or soft gel type can also be considered for application. Common administration dosage can be specifically prepared according to symptoms, but the usual dosage is 50 mg to 300 mg each time per person, three times per day.
[0050] It is generally speaking, administration dosage of the invention are prefect using on soft gel, cream, tincture and aerosol etc. topical dosage. That shall be added with various additives, enhaner such as BHT, Oleth.2 (CTFA), Isoceteth-20 (CTFA), Ascorbyl palmitate, PEG-8 (CTFA), Sorbitol solution, EDTA, Silicon, Sodium bisulfate, Emulage 100 Nl, Ascorbic acid, Propylene glycol, Sodium lauryl sulfate. The CTMs extracts usually diluted to expedient concentration, such as 10%, 2%, 5%, then add to mix components of other parts. Those topical dosage of cream or soft gel was prepared by admixing the components of Part A and heating to a melt temperature. Agitation was continued until all of the solids were blended. In a separate vessel, the components of Part B were admixed and heated till melt, with continued agitation until all the solids were dissolved. Part B was mixed into Part A and agitation continued, while maintaining a liquid temperature, until both parts were thoroughly blended. The resulting cream was cooled to packaging temperature and packaged.
[0051] The topical dosage of CTMs extracts for psoriasis on this invention, that select from Tripterygiim Wilfordii 1, Caulis Spatholobi 2, Radix Angelicae Sinensis 3, Rhizoma Smilacis Glabrae 4, Rhizoma Sparganii 5, Radix Rehmanniae Exsiccata 6, Radix Ophiopogonis Japonici 7, Radix Asparagi 8, Olibanum 9, Nidus Vaspae 10, Herba Hedyotis 11, Indigo Naturalis 12, Radix Lithospermi 13, Radix Salviae Miltiorrhizae 14, Rhizoma Curcumae Aeruginosae 15, Myrrha 16, Radix Paeoniae Veitchii 17, Pericarpium Citri Reticulatae 18, Flos Carthami 19, Semen Amygdalus Persicae 20, Radix Angelicae Biserratae 21, Radix Angelicae Hangbaizhi, or Radix Angelicae Qibaizhi 22, Rhizoma Imperatae 23, Herba Artemisiae Anomalae 24, Polyporus 25, Ramulus Euonymi 26, Flos Sophorae 27, prescription (A) , Prescription (B), and Prescription (C).
[0052] The following H 2 O extracts of CTMs are prefect which is Radix Tripterygiim Wilfordii 1, Radix Angelicae Sinensis 3, Radix Ophiopogonis Japonici 7, Olibanum 9, Radix Salviae Miltiorrhizae 14, Rhizoma Curcumae Aeruginosae 15, Myrrha 16, Radix Paeoniae Veitchii 17, Pericarpium Citri Reticulatae 18, Flos Carthami 19, Radix Angelicae Hangbaizhi, or Radix Angelicae Qibaizhi 22, Rhizoma Imperatae 23, Herba Artemisiae Anomalae 24, Ramulus Euonymi 26, Flos Sophorae 27, prescription (A), and Prescription (B). On the other hands, following ethanol extracts of CTMs are prefect which is Rhizoma Sparganii 5, Pericarpium Citri Reticulatae 18, Semen Amygdalus Persicae 20, Herba Artemisiae Anomalae 24, and Polyporus 25.
[0053] The CTMs were subjected to be boiled in distilled water at 100□ for 1 h or organic solvents (ethanol, acetone, dichloromethan) at room temperature for one month; the extract of each CTMs was dried. Then put on Dianon gel, silica gel, and sephadex LH-20 gel column to make the fraction. To understand whether the antipsoriatic CTMs could possess both antioxidative and antiproliferative activity, so the each activity fraction, extract of the 27 CTMs and 3 combination prescriptions be prove through experiments.
[0054] On the Dianon gel chromatography column, from 100% H 2 O to 100% Methanol of H 2 O-Methanol graduate solution are elute to separate the fraction. The graduate solution of Dichloromethan-Methanol, hexane-Ethyl acetate, Ethyl acetate-Methanol, hexane-Dichloromethan graduate solution are elute on silica gel. Graduate solution of H 2 O-Methanol, Dichloromethan-Methanol, are elute on sephadex LH-20 gel.
[0055] The purpose of the invention was to evaluate the antioxidative properties and antiproliferative activity of CTMs and to determine which CTM is potential treatment for psoriasis. Through the lipid peroxidation of various extract of CTMs and antiproliferative activity against HaCaT cells by CTMs. The antioxidative and antiproliferative mechanisms of these CTMs, however, have not yet been clarified, and it was for this reason that the present investigation was carried out. The results of several CTMs on lipid peroxidation and cytotoxicity against HaCaT cells in vitro enabled us to assess the antipsoriatic activity of CTMs themselves.
[0056] Based on the results, the effects of 27 CTMs and 3 prescriptions on lipid peroxidation and antiproliferative activity were evaluated. Some of the investigated CTMs showed significant antioxidation or prooxidation against LP and antiproliferative activity. The IC 50 values of antiproliferative activity of CTMs are given in Table 1.
[0057] Results from the HaCaT keratinocyte proliferation assay show that most CTMs are significantly efficient, expect 13, 15, 22, 26 and 30. Although all the CTMs showed similar significant inhibition of lipid peroxidation in brain homogenate, some different antioxidative and antiproliferative mechanism could be recognized between them from the following results: (i) in antiproliferative activity assay, some CTMs showed inhibition against HaCaT cells, but some did not; (ii) H 2 O-extract of CTMs on LP, only Nos. 1, 2, 4, and 5 showed significant inhibitory effects but Nos. 6, 8, 11, 12, 13, 20, 21 and 30 showed prooxidative activity, respectively; (iii) Ethanol (EtOH)-extract of CTMs on LP, Nos. 1, 2, 4, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 22, 26 and 27 showed significant inhibitory effects but Nos. 3, 12, 17, 19, 21 and 23 showed prooxidative activity, respectively; (iv) acetone-extract of CTMs on LP, Nos. 1, 2, 3, 4, 7, 14, 15, 16, 17, 23, 26 and 27 showed significant inhibitory effects but Nos. 9, 13, 19 and 20 showed prooxidative activity, respectively; (v) Dichloromethan-extract of CTMs on LP, Nos. 1, 2, 3, 4, 5, 6, 7, 10, 14, 15, 16, 17, 18, 22, 23, 26 and 27 showed significant inhibitory effects but only Nos. 9, 12, and 13 showed prooxidative activity, respectively. Table 2 shown Inhibitory effects of various solvents extract of CTMs on LP of rat brain homogenate induced by FeCl 2 in vitro. Table 3 shown prooxidative effects of various solvents extract of CTMs on LP of rat brain homogenate induced by FeCl 2 in vitro.
[0058] In some cases, the mechanism of antioxidation and antiproliferation in the same CTM differed. For instance, Nos. 13, 15, 22 and 26 showed an inhibition on LP, but this was not observed in antiproliferative activity assay. Nos. 1, 2, 3, 10 and 17 showed an inhibition on LP, and these were also observed in antiproliferative activity assay. In some cases, the results of LP in the various extracts of CTM were also different. For instance, Nos. 3, 6, 8, 9, 11, 12, 13, 17, 19, 20 and 21 showed antioxidative and prooxidative activity, respectively. Nos. 1, 2, 3, 6, 10, 12, 17, 21, 25, 27, 28 and 29 showed significant inhibition in antiproliferative activity assay, but only Nos. 1, 2, 3, 6, 10, 17 and 27 also showed significant inhibition on LP. These results suggest that the inhibition of those CTMs may be an important factor in their biological activity.
[0059] A variety of hyperproliferative and inflammatory skin diseases are characterized by increased levels of proinflammatory arachidonic acid metabolites. Reactive oxygen species (ROS) and hydroperoxides that are generated during inflammatory reactions may play an important role in the regulation of these proliferative processes. Lipid is a major target for oxidative damage in cells. Lipid hydroperoxides are key intermediates in the lipid peroxidation process serving as initiators for free radical chain reactions. Because lipid peroxidation can be detrimental to cells, we hypothesized that some CTMs would increase the resistance of cells to oxidative stress. Nevertheless, the relationship between the biosynthesis of lipoxygenase products and ROS is not well defined. The purpose of the invention was to evaluate the effects of CTMs on the lipid peroxidation and antiproliferative HaCaT keratinocyte cells in vitro. The inhibitory effect on lipid peroxidation in brain homogenate and inhibition against HaCaT cells are considered to be due to their peculiar chemical structures and components, as part of their special different chromophore in various extract they scavenge the radicals.
[0060] It is well know that CTMs are compound medicines, which are combined with various crude drugs, and the exhibition of their pharmacologic activity is the result of the pharmacodynamic interaction of the combined drugs and their components. Extensive studies have revealed that various CTMs have potential antipsoriatic activity. The structure activity relationship (SAR) of these CTMs is still unclear and requires further research. Up to now, the invention have shown that CTMs can be markedly to a potent treatment for psoriasis. That said that antioxidative and antiproliferative activities of some CTMs strongly correlated with various biological endpoints support the importance of psoriasis. This could be an advantage or disadvantage, depending on the diagnosis and certain disease treatment. The combination use of CTMs is also accompanied by partially diminished oxygen-radical formation and reversal of the enhancement of lipid peroxidation to potent inhibition of psoriatic process. This promises less skin inflammation and suggests an additional protective action against tissue injury. In the future, when treating severe cases with major constitutional disturbances, physician may consider the modality of combining CTMs with modern western medicines in consideration of the patients.
[0061] There is no appropriate animal model of psoriasis, for prove the biological activity of drugs useful as antipsoriatic agents even that were evaluated by antiproliferative activity in cell cultures and antioxidative activity.
[0062] Table 4 presents the clinical evaluation some psoriasis patients. Comparison of these experimental values for the psoriasis suggests that the effective of the patient for the test compounds is A drug better than B drug.
[0063] It is observed in general that a stain of 5 minutes duration can be removed easily with water or solvents. The longer the stain remains on the skin the more difficult it is to remove. This procedure was repeated twice to obtain the best result. Based on effective activity and observed side effect with CTMs is probably due to the result of the therapy process. This was supported by complaint of psoriasis patients in which the major uncomfortable all disappeared. It is therefore reasonable to presume that the intermediate products and stain might be neglect.
[0064] Based on the information generated in this study, it is recommended that 2% of extract, whether Radix Tripterygiim Wilfordii 1 is A drug, and Prescription (A) is B drug. The extract used full strength, is the best prescription for psoriasis. For psoriasis patients, the extract should be diluted 1:1,000, 1:5,000 and 1:20,000, respectively. Although the CTMs composition of the present invention are capable of being formulated and used in cream, gel, ointment or tincture, for each of application the cream or tincture forms are prepared. While the present invention has been described by means of the foregoing specification, reference should be had to the appended claim for a definition of the scope of the invention. As a result, several CTMs are currently in preclinical anti-inflammatory, antiproliferative, and toxicological studies.
[0065] While the invention is susceptible to various modifications and alternative forms, certain illustrative embodiments thereof have been shown by way of example in the drawing and will herein be described in detail. It should be understood that it is not intended to limit the invention to the particular forms disclosed, but the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention, as defined by the appended claims.
[0066] Anyone who is familiar with the said technique is able to amend and/or apply the said technique partially or totally without going beyond the Invention's spirit and coverage. Thus, the protection coverage of the Invention is determined by the descriptions stated in the application of patents.
Pharmaceutical Activity
[0067] The pharmaceutical activity of the Chinese traditional medicines of this invention has been proven by the following pharmaceutical experiments.
[0068] On the basis of this information, evaluated the ability of the Chinese traditional medicines (CTMs) to inhibit the growth of human keratinocytes and lipid peroxidation in model membrane of rat brain homogenate induced by FeCl 2 in vitro.
[0069] Chinese traditional medicines (CTMs) used in this study were purchased from market and identified. Thiobarbituric acid, tetramethoxypropane and trichloroacetic acid were purchased from Sigma Chemical Co. Thin layer chromatography (TLC) plastic sheets silica gel 60 F 254 were from Merck (Darmstadt, Germany). All other materials and solvents were of the highest purity or high-performance liquid chromatography (HPLC) grade. CTMs prepared by their traditional recipe, HaCaT keratinocyte cells were received as a gift from Prof. Dr. K. Müller (Universität Münster, Germany) and Prof. Dr. W. Wiegrebe (Universität Regensburg, Germany).
HaCaT Keratinocyte Cells Culture
[0070] HaCaT Keratinocyte cells were growth in culture using a modification of the method as described by Huang H S. et al., J. Med. Chem. 39:3132-8,1996. In vitro cultured cell system are useful tools in identifying new topical antipsoriatic agents. HaCaT keratinocytes can be used as a model for highly proliferative epidermis, e.g. psoriasis, and this nontransformed human cell line was described as an extremely sensitive target for the antiproliferative action of dithranol (anthralin). by Müller K. Biochem. Pharmacol. 53, 1215-21, 1997. Proliferation of the keratinocytes was determined directly by counting the dispersed cells under a phase-contrast microscope after 48 h of treatment. The CTMs in Table 1 were tested for antiproliferative effects as demonstrated by reduction in cell number over time as compared to control plates.
Antiproliferative Activity
[0071] The immortalized keratinocyte line HaCaT cells were used to mimic the hyperproliferative epidermis found in psoriasis, as antiproliferative action in cell cultures may be critical in the management of the proliferative component of psoriasis. In vitro cultured cell systems are useful tools in identifying new topical antipsoriatic agents. Proliferation of the keratinocyte was determined directly by counting the dispersed cells under a phase-contrast microscope after 48 h of treatment. The Chinese traditional medicines in Table 1 were tested for antiproliferative effects as demonstrated by reduction in cell number over time as compared to control plates. The results of this assay are also provided in Table 1.
Assay of Lipid Peroxidation
[0072] Rat brain homogenate was prepared from the brains of freshly killed Wistar rats and its peroxidation in the presence of iron ions was measured by the thiobarbituric acid (TBA) method as described by Teng CM. et al. Eur J Pharmacol 303:129-39, 1996. Tetramethoxypropane was used as a standard, and the results were expressed as nanomoles of MDA equivalents per milligram of protein of rat brain homogenates. The amount of LP in this method was expressed in terms of malondialdehyde (MDA). In brief, whole brain tissue, excluding the cerebellum, was washed and homogenized in 10 volumes of ice-cold Krebs buffer (10 mM N-2-hydroxyethyl piperazine-N′-2-ethanesulfonic acid (Hepes), 10 mM glucose, 140 mM NaCl, 3.6 mM KCl, 1.5 mM CaCl 2 , 1.4 mM KH 2 PO 4 , 0.7 mM MgSO 4 , pH 7.4) using a glass Dounce homogenizer. The homogenate was centrifuged at low speed (1000×g) for 10 min, and the resulting supernatant (adjusted to 2 mg/ml) was used immediately in lipid peroxidation assays. The reaction mixture with test compounds or vehicle was incubated for 10 min, then stimulated by addition of ferrous ion (200 μM, freshly prepared), and maintained at 37° C. for 30 min. The reactions were terminated by adding 10 μl of ice-cold trichloroacetic acid solution (4% (w/v) in 0.3 N HCl) and 200 μl of thiobarbituric acid-reactive substance reagent (0.5 % (w/v) thiobarbituric acid in 50 % (v/v) acetic acid). After boiling for 15 minutes, the samples were cooled and extracted with 1-butanol. The extent of lipid peroxidation was estimated as thiobarbituric acid-reactive substances and was read at 532 nm in a spectrophotometer (Shimadzu UV-160). The results of this assay are provided in Table 2.
Clinical Evaluated on Psoriasis Patients
[0073] Collect the Clinical psoriasis patients at Trisurvice-general hospital, the 2% cream are contact the 10 mm psoriasis area, 5% are contact the 20 mm psoriasis area, 10% cream are contact over 50 mm psoriasis area.
Example 1
Preparation of Aqueous CTMs Extract
[0074] Powdered of commercially available dried and smashed CTMs (1,000 g) were added with 3,000 ml of distilled water, and boiled until the volume of aqueous extract was reduced to 500 ml. The extracts were pooled and filtered through absorbent cotton. The filtrate was then concentrated under reduced pressure and freeze-dried to give a powder.
Example 2
Preparation of Organic Layer CTMs Extract
[0075] Powered of commercially available dried and smashed CTMs (1,000 g) were added with 2,000 ml of organic solvents (ethanol, acetone, Dichloromethan) at room temperature in the dark room. After one month, the solvent was filtered and concentrated under reduced pressure and freeze-dried to give a brown solid extract powder.
Example 3
Preparation the Activity Fraction of Aqueous CTMs
[0076] Powdered of commercially available dried and smashed CTMs (1,000 g) were added with 3,000 ml of distilled water, and boiled until the volume of aqueous extract was reduced to 500 ml. The extracts were pooled and filtered through absorbent cotton. The filtrate was then concentrated under reduced pressure and freeze-dried to give a powder. Then put on Dianon gel, silica gel, and sephadex gel column to make the activity fraction.
Example 4
Preparation the Activity Fraction of Organic Layer CTMs
[0077] Powered of commercially available dried and smashed CTMs (1,000 g) were added with 2,000 ml of organic solvents (ethanol, acetone, Dichloromethan) at room temperature in the dark room. After one month, the solvent was filtered and concentrated under reduced pressure and freeze-dried to give a brown solid extract powder. Then put on Dianon gel, silica gel, and sephadex gel column to make the activity fraction.
Example 5
Soft Gel Composition
[0078] Part A:
Mineral oil (USP) 16.0 g Propyl gallate 0.01 g BHT 0.1 g Oleth.2 (CTFA) 6.0 g Isoceteth-20 (CTFA) 20.0 g Ascorbyl palmitate 0.1 g CTM extract 5.0 g
[0079] Part B:
PEG-8 (CTFA) 5.0 g Sorbitol solution (70%) 2.0 g EDTA 0.01 g Sodium bisulfate 0.05 g Ascorbic acid 1.0 g Sodium lauryl sulfate 0.1 g Pured water (USP) q.s 100.0
[0080] Admixing the components of part A, and heating to a temperature of 90□. Agitation was continued until all of the solids were blended. The components of part B were admixed in a separate vessel and heated to 90□ with continued agitation until all the solids dissolved. Part B was added to part A and the resultant mixture agitated. Agitation was continued for ten minutes, while maintaining the temperature at 90□. The resulting gel was cooled to packaging temperature and packaged, under an inert gas, in aluminum tubes suitable coated internally so as not to react with the product.
Example 6
Cream Composition
[0081] Part A:
Peanut oil 4.0 g Silicon 3.0 g BHT 0.1 g Prescription (A) extract 5.0 g
[0082] Part B:
Emulage 100 NI 15.0 g Sodium phosphate tribasic 1.0 g EDTA 0.1 g Propylene glycol 5.0 g Pured water (USP) q.s 100.0 g
[0083] The cream was prepared by admixing the components of Part A and heating to a temperature of 70□. Agitation was continued until all of the solids were blended. In a separate vessel, the components-of Part B were admixed and heated to 70□, with continued agitation until all the solids were dissolved. Part B was mixed into Part A and agitation continued, while maintaining a temperature of 70□, until both parts were thoroughly blended. The resulting cream was cooled to packaging temperature and packaged.
TABLE 1 Antiproliferative activity against HaCaT cells by CTMs. AA a IC 50 (□g/ml) No Chinese traditional medicines H 2 O extract 1 Radix Tripterygiim Wilfordii 8.1 ± 0.1 2 Canlis Spatholobi 69.7 ± 1.1 3 Radix Angelicae Sinensis 49.5 ± 0.4 6 Radix Rehmanniae Exsiccata 91.7 ± 0.7 10 Nidus Vaspae 84.9 ± 0.8 12 Indigo Naturalis 100.5 ± 1.5 13 Radix Lithospermi 564.2 ± 8.2 15 Rhizoma Curcumae Aeruginosae 467.0 ± 7.1 17 Radix Paeoniae Veitchii 50.9 ± 0.3 21 Radix Angelicae Biserratae 40.9 ± 0.4 22 Radix Angelicae Hangbaizhi, or Radix 424.7 ± 7.5 Angelicae Qibaizhi 25 Polyporus 54.1 ± 0.6 26 Ramulus Euonymi 425.6 ± 9.1 27 Flos Sophorae 102.5 ± 0.6 28 Prescription (A) 44.1 ± 0.3 29 Prescription (B) 49.9 ± 0.4 30 Prescription (C) 635.1 ± 9.5 a Antiproliferative activity against HaCaT cells. Inhibition of cell growth was significantly different with respect to that of the control, N = 3, P < 0.01. b Prescription (A): 2, 6, 13, 14, 17, 23, and 27. c Prescription (B): 2, 3, 4, 6, 7, 8, 10 and 14. d Prescription (C): 2, 5, 11, 15, 18, 19, 20, and 26.
[0084]
TABLE 2
Inhibitory effects a of various solvents extract of
CTMs on LP of rat brain homogenate induced by FeCl 2 in vitro.
Percentage inhibition of lipid peroxidation a
H 2 O
Ethanol
acetone
Dichloromethan
No
CTMs
extract
extract
extract
extract
1
Radix Tripterygiim Wilfordii
78.9
100
100
100
2
Canlis Spatholobi
100
98.5
100
100
3
Radix Angelicae Sinensis
17.9
−22.2
100
100
4
Rhizoma Smilacis Glabrae
97.5
98.9
100
100
5
Rhizoma Sparganii
74.2
32.8
20.2
100
6
Radix Rehmanniae Exsiccata
−60.2
60.4
16.9
69.7
7
Radix Ophiopogonis Japonici
8.6
87.4
100
100
8
Radix Asparagi
−52.3
78.1
15.3
27.9
9
Olibanum
10.6
81.7
−56.5
−1.5
10
Nidus Vaspae
55.3
94.1
26.2
100
11
Herba Hedyotis
−72.9
94.0
30.6
10.6
12
Indigo Naturalis
−70.4
−51.0
13.4
−3.1
13
Radix Lithospermi
−8.7
100
−100
−100
14
Radix Salviae Miltiorrhizae
9.1
100
100
100
15
Rhizoma Curcumae Aeruginosae
2.4
100
100
100
16
Myrrha
12.9
98.0
100
100
17
Radix Paeoniae Veitchii
19.8
−27.4
100
100
18
Pericarpium Citri Reticulatae
0.1
20.7
35.4
100
19
Flos Carthami
15.9
−24.2
−19.1
48.7
20
Semen Amygdalus Persicae
−5.2
29.9
−27.5
23.8
21
Radix Angelicae Biserratae
−25.2
−27.7
24.1
56.2
22
Radix Angelicae Hangbaizhi, or
32.8
85.3
11.6
100
Radix Angelicae Qibaizhi
23
Rhizoma Imperatae
18.4
−50.6
100
100
24
Herba Artemisiae Anomalae
2.9
31.1
10.3
45.9
25
Polyporus
ND b
26.3
ND b
ND b
26
Ramulus Euonymi
16.4
100
100
100
27
Flos Sophorae
0.6
92
100
66.5
28
Prescription (A)
27.4
ND b
ND b
ND b
29
Prescription (B)
32.0
ND b
ND b
ND b
30
Prescription (C)
−3.8
ND b
ND b
ND b
a Relative percentage of inhibition, P < 0.01, Mean ± S.E., n = 4. Values in parentheses are percent inhibition at the indicated concentration (100□g/ml), and standard errors average 10% of the indicated values.
b ND = not determined.
[0085]
TABLE 3
Prooxidative effects a of various solvents extract of CTMs on
LP of rat brain homogenate induced by FeCl 2 in vitro.
Percentage prooxidation of LP a
Dichloro-
H 2 O
Ethanol
acetone
methan
No
CTMs
extract
extract
extract
extract
6
Radix Rehmanniae
−60.2
Exsiccata
8
Radix Asparagi
−52.3
9
Olibanum
−56.5
−1.5
11
Herba Hedyotis
−72.9
12
Indigo Naturalis
−70.4
−51.0
−3.1
13
Radix Lithospermi
−8.7
−100
−100
19
Flos Carthami
−24.2
−19.1
20
Semen Persicae Persicae
−5.2
−27.5
23
Rhizoma Imperatae
−50.6
a Relative percentage of inhibition, P < 0.01, Mean ± S.E., n = 4. Values in parentheses are percent inhibition at the indicated concentration (100□g/ml), and standard errors average 10% of the indicated values.
[0086]
TABLE 4
Clinical evaluated on psoriasis patients
Administration
Clinical
response No. of patients/
drug
time
response
total No. of patients
0.1% A drug
30 days
excellent
7/12
better
4/12
0.5% A drug
30 days
excellent
8/12
better
3/12
2% A drug
30 days
excellent
9/12
better
2/12
0.1% B drug
30 days
excellent
4/12
better
3/12
0.5% B drug
30 days
excellent
5/12
better
3/12
2% B drug
30 days
good
6/12
better
2/12
A drug: Radix Tripterygiim Wilfordii 1 A drug
B drug: Prescription (A)
[0087] While there is shown and described the present preferred embodiment of the invention, it is to be distinctly understood that this invention is not limited thereto but may be variously embodied to practice within the scope of the following claims. From the foregoing description, it will be apparent that various changes may be made without departing from the spirit and scope of the invention as defined by the following claims.
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A topical treatment for both the hyperproliferative and inflammatory aspects of psoriasis utilizing combinations of traditional Chinese medicines. The topical treatment is most often administered through a medium such as a soft gel, cream, tincture or aerosol.
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[0001] This U.S. Non-Provisional Application is related to U.S. Non-Provisional application Ser. No. ______ (MERL-2882) co-filed herein with and incorporated herein by reference. That Application discloses a system and method for hybrid simultaneous localization and mapping of 2D and 3D data in images acquired by a red, green, blue, and depth sensor of a 3D scene.
FIELD OF THE INVENTION
[0002] This invention relates generally to computer vision and image processing, and more particularly to detecting and tracking objects using images acquired by a red, green, blue, and depth (RGB-D) sensor and processed by simultaneous localization and mapping (SLAM).
BACKGROUND OF THE INVENTION
[0003] Object detecting, tracking, and pose estimation can be used in augmented reality, proximity sensing, robotics, and computer vision applications using 3D or RGB-D data acquired by, for example, an RGB-D sensor such as Kinect®. Similar to 2D feature descriptors used for 2D-image-based object detection, 3D feature descriptors that represent the local geometry can be defined for keypoints in 3D point clouds. Simpler 3D features, such as point pair features, can also be used in voting-based frameworks. Those 3D-feature-based approaches work well for objects with rich structure variations, but are not suitable for detecting objects with simple 3D shapes such as boxes.
[0004] To handle simple as well as complex 3D shapes, RGB-D data have been exploited. Hinterstoisser et al. define multimodal templates for the detection of objects, while Drost et al. define multimodal pair features for the detection and pose estimation, see Hinterstoisser et al., “Multimodal templates for real-time detection of texture-less objects in heavily cluttered scenes,” Proc. IEEE Int'l Conf. Computer Vision (ICCV), pp. 858-865, November 2011, and Drost et al., “3D object detection and localization using multimodal point pair features,” in Proc. Int'l Conf. 3D Imaging, Modeling, Processing, Visualization and Transmission (3DIMPVT), pp. 9-16, October 2012.
[0005] Several systems incorporate object detection and pose estimation into a SLAM framework, see Salas-Moreno et al., “SLAM++: Simultaneous localization and mapping at the level of objects,” in Proc. IEEE Conf. Computer Vision and Pattern Recognition (CVPR), June 2013, and Fioraio et al., “Joint detection, tracking and mapping by semantic bundle adjustment,” in Proc. IEEE Conf. Computer Vision and Pattern Recognition (CVPR), 2013, pp. 1538-1545. Salas-Moreno et al. detect objects from depth maps and incorporate the objects as landmarks in a SLAM map for bundle adjustment. Their method only uses 3D data, and thus requires rich surface variations for objects. Fioraio et al. use a semantic bundle adjustment approach for performing SLAM and object detection simultaneously. Based on a 3D model of the object, they generate a validation graph that contains the object-to-frame and frame-to-frame correspondences among 2D and 3D point features. Their method lacks a suitable framework for object representation, resulting in many outliers after correspondence search. Hence, the detection performance depends on bundle adjustment, which might become slower as the map grows.
SUMMARY OF THE INVENTION
[0006] The embodiments of our invention provide a method and system for detecting and localizing objects using a red, green, blue, and depth (RGB-D) image data acquired by a 3D sensor using hierarchical feature grouping.
[0007] The embodiments use a novel compact representation of objects by grouping features hierarchically. Similar to a keyframe being a collection of features, an object is represented as a set of segments, where a segment is a subset of features in a frame. Similar to keyframes, segments are registered with each other in an object map.
[0008] The embodiments use the same process for both offline object scanning and online object detection modes. In the offline scanning mode, a known object is scanned using a hand-held RGB-D sensor to construct an object map. In the online detection mode, a set of object maps for different objects are given, and the objects are detected via an appearance-based similarity search between the segments in the current image and in the object maps.
[0009] If a similar segment is found, the object is detected and localized. In subsequent frames, the tracking is done by predicting the poses of the objects. We also incorporate constraints obtained from the object detection and localization into the bundle adjustment to improve the object pose estimation accuracy as well as the SLAM reconstruction accuracy. The method can be used in a robotic application. For example, the pose is used to pick up an object. Results show that the system is able to detect and pick up objects successfully from different viewpoints and distances.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic of hierarchical feature grouping using object and SLAM maps according to embodiments of the invention;
[0011] FIG. 2 is a schematic of a method and system for object detection and localization according to embodiments of the invention; and
[0012] FIG. 3 is a schematic of a SLAM system and method according to embodiments of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] Object Detection and Localization
[0014] As shown in FIG. 2 , the embodiments of our invention provide a method and system 200 for detecting and localizing objects in frames (images) 203 acquired of a scene 202 by, for example, a red, green, blue, and depth (RGB-D) sensor 201 . The method can be used in a simultaneous localization and mapping (SLAM) system and method 300 as shown in FIG. 3 . In the figures generally, solid lines indicate processes and process flow, and dashed lines indicate data and data flow. The embodiments use segment sets 241 and represent an object in an object map 140 including a set of registered segment sets.
[0015] Both an offline scanning and online detection modes are described in a single framework by exploiting the same SLAM method, which enables instant incorporation of a given object into the system. The invention can be applied to a robotic object picking application.
[0016] FIG. 1 shows our hierarchical feature grouping. A SLAM map 110 stores a set of registered keyframes 115 , each associated with a set of features 221 . We use another hierarchy based on segments 241 to represent an object. A segment contains a subset of features 221 in a keyframe, and an object map 140 includes a set of registered segments. The object map is used for the object detection and pose estimation as described below. In our system, the segments can be generated by depth-based segmentation.
[0017] One contribution of the invention is representing objects based on the hierarchical feature grouping as shown in FIG. 1 . Just as a keyframe is a collection of features, a subset of features in a frame or image defines a segment. A keyframe-based SLAM system constructs the SLAM map 110 containing keyframes registered with each other. Similarly, we group a set of segments registered with each other to generate the object map 140 corresponding to the object. Because an instance of an object in a frame can contain multiple segments, the object map can contain multiple segments from a single frame. The object map provides a compact representation of the object observed under different viewpoint and illumination conditions.
[0018] Our system exploits the same SLAM method to handle offline object scanning and online object detection modes. Both modes are essential to achieve an object detection and localization that can incorporate a given object instantly into the system. The goal of the offline object scanning is to generate the object map 140 by considering appearance and geometry information of known objects. We perform this process with user interaction. The system displays candidate segments that might correspond to the object to the user. Then, the user selects the segments corresponding to the object in each keyframe that is registered with the SLAM system.
[0019] During online object detection, the system takes a set of object maps corresponding to different objects as the input, and then localizes these object maps with respect to the SLAM map that is generated during the online SLAM session.
[0020] Our system first generates 240 sets of one or more segments 241 from each frame 203 using the depth-based segmentation procedure based on the features. For example, if the object is a box, for a particular view, the features described as be planes, edges and corners, which essentially are associated descriptors of the features.
[0021] An appearance similarity search 260 , using vector of locally aggregated descriptors (VLAD) and the segment sets, is performed to determine similar sets of segments 266 . The searching 260 can use an appearance based similarity search of the object map 140 . If 262 the search is unsuccessful, the segment set is discarded 264 .
[0022] Otherwise, if the search is successful, random sample consensus (RANSAC) registration 270 is performed to localize the segment set in the current frame with the object map. Set of segments with successful 275 RANSAC registration initiate objects in the SLAM map 110 as object landmark candidates. The pose of such objects can then be predicted 280 .
[0023] The pose of each object landmark candidate is refined 285 by a prediction-based registration, and when it is successful, the candidate becomes an object landmark. The list of object landmarks are merged 286 by identifying the refined poses, i.e., if two object landmarks correspond to the same object map and have similar poses, then the landmarks are merged. The refining and merging steps are optional to achieve more accurate results.
[0024] The output includes a detected object and pose 290 . The method can be performed in a processor connected to memory, input/output interfaces and the sensor by buses as known in the art.
[0025] The method can be repeated for a next frame with the sensor at a different viewpoint and pose.
[0026] In subsequent frames, we can use the same prediction-based registration and merging processes to track the object landmarks. Consequently, an object landmark in the SLAM map serves as the representation of the object in the real world. Note that this procedure applies to both the offline object scanning and online object detection modes. In the offline mode, the object map is incrementally constructed using the segment sets specified in the previous keyframes, while in the online mode the object map is fixed.
[0027] Object Detection and Localization Via Hierarchical Feature Grouping
[0028] Our object detection and tracking framework is based in part on a point-plane SLAM system, see Taguchi et al., “Point-plane SLAM for hand-held 3D sensors,” Proc. IEEE Int'l Conf. Robotics and Automation (ICRA), pp. 5182-5189, May 2013.
[0029] That point-plane SLAM system localizes each frame with respect to a SLAM map using both 3D points and 3D planes as primitives. An extended version uses 2D points as primitives and determines 2D-to-3D correspondences as well as 3D-to-3D correspondences to exploit information in regions where the depth is not available, e.g., the scene point is too close or too far from the sensor.
[0030] Our segments include 3D points and 3D planes (but not 2D points) as features, while the SLAM procedure exploits all the 2D points, 3D points, and 3D planes as features to handle the case where the camera is too close or too far from the object and depth information is not available.
[0031] Only segments that have similarity scores greater than a predetermined threshold are returned to eliminate segments that do not belong to any objects of interest. Then the set of segments in the frame are registered with the similar sets of segments in the object map. During the registration, we perform all-to-all descriptor similarity matching between the point features of the two segment sets followed by the RANSAC-based registration 270 that also considers all possible plane correspondences. The segment set that generates the largest number of inliers is used as the corresponding object. If 275 RANSAC fails for all of the k similar segment sets in the object maps, then the segment set extracted from the frame is discarded 264 .
[0032] This step produces object landmark candidates. We consider these object landmarks as candidates, because the segments are only registered with a single segment set in the object map, not with the object map as a whole. An object can also correspond to multiple segments in the frame, resulting in repetitions in this list of object landmark candidates. Thus, we proceed with a pose refinement 285 and merging 286 .
[0033] Prediction-Based Object Registration
[0034] We project all point and plane landmarks of the object map to the current frame based on the predicted pose of the object landmark candidate. Matches between point measurements of the current frame and point landmarks of the object map are determined. We ignore unnecessary matches based on two rules:
(i) a point measurement is matched with a point landmark when the projected landmark is within a r pixel neighborhood, for example, r is 10; and (ii) a point measurement is matched with a point landmark when the landmark is at a similar viewing angle when the object map was constructed.
[0037] The first rule avoids unnecessary point pairs that are too far on the object, and the second rule avoids performing matches for point landmarks that are behind the object from the current viewing angle of the frame.
[0038] Similarly, a plane measurement is considered a candidate match when it is visible from the viewing angle used for the frame. Note that the object map is matched with the features included in the segments, and with all the features in the frame. Thus, this step does not assume any depth-based segmentation and can work with object landmark candidates initiated using other methods, e.g., 2D-image-based detection methods.
[0039] Merging
[0040] Because an object in the frame can include multiple segments, the list of object landmarks can include redundancies. Therefore, we merge 286 the object landmarks that have similar poses, belonging to the same object.
[0041] SLAM System
[0042] FIG. 3 is a schematic of a SLAM system and method 300 according to the embodiments of the invention that uses the object detection and localization as shown in FIG. 2 .
[0043] As before, frames are acquired 210 . In step 310 , we determine whether the SLAM map 110 includes any objects. If no, we apply the object detection and localization method 200 to the next frame to produce detected objects and poses 290 . If yes, we apply the prediction-based object localization 320 , followed by the object detection and localization 200 . Step 350 merges object poses.
[0044] Step 360 determines if any of the detected objects are not in the SLAM map, i.e., the objects are new. If not, process the next frame 380 . Otherwise, add 370 a keyframe and the new object to the SLAM map 110 .
[0045] SLAM Map Update
[0046] In a SLAM system, the frame is added to the SLAM map as a keyframe when the pose is different from the poses of any existing keyframes in the SLAM map. We can also add a frame as a keyframe when the frame includes new object landmarks to initialize the object landmarks and maintain the measurement-landmark associations.
[0047] Bundle Adjustment
[0048] Bundel adjustment 340 can be applied to the SLAM map. Bundle adjustment refines the 3D coordinates describing the scene and relative motion obtained from images depicting the 3D points from different viewpoints. The refinement incorporates constraints obtained from the object detection and localization.
[0049] A triplet (k, l, m) denotes an association between feature landmark p l and feature measurement p m k of keyframe k with pose T k . Let I contain the triplets representing all such associations generated by the SLAM system in the current SLAM map. A tuple (k, l, m, o) denotes an object association, such that the object landmark o with pose {tilde over (T)} o contains an association between the feature landmark p l o of the object map and feature measurement p m k in keyframe k. I o contains the tuples representing such associations between the SLAM map and the object map.
[0050] An error E kf that comes from the registration of the keyframes in the SLAM map is
[0000] E kf ( p 1 , . . . , p L ; T 1 , . . . , T K )=Σ (k,l,m)∈I d ( p l , T k −1 ( p m k )), (1)
[0000] where d(•,•) denotes the distance between a feature landmark and a feature measurement and T(f) denotes application of transformation T to the feature f.
[0051] An error E obj due to object localization is
[0000] E obj ( T 1 , . . . , T K ; {tilde over (T)} 1 , . . . , {tilde over (T)} O )=Σ (k,l,m,o)∈I o d ( p l o , {tilde over (T)} o T k −1 ( p m k )). (2)
[0052] The bundle adjustment minimizes a total error with respect to the landmark parameters, keyframe poses, and object poses:
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Effect of the Invention
[0053] The embodiments of the invention provide a method and system for detecting and tracking objects that can be used in a SLAM system. The invention provides a novel hierarchical feature grouping that uses segments, and represents an object as an object map including a set of registered segments. Both the offline scanning and online detection modes are described by a single framework exploiting the same SLAM procedure, which enables instant incorporation of a given object into the system. The method can be used in an object picking application. For example, the pose is used to pick up an object.
[0054] The representations described herein are compact. Namely, there is an analogy between keyframe-SLAM map and segment-object map pairs, respectively. Both use the same features, i.e., planes, 3D points, and 2D points that are extracted from input RGB-D frames.
[0055] Although the invention has been described by way of examples of preferred embodiments, it is to be understood that various other adaptations and modifications can be made within the spirit and scope of the invention. Therefore, it is the object of the appended claims to cover all such variations and modifications as come within the true spirit and scope of the invention.
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A method and system detects and localizes an object by first acquiring a frame of a three-dimensional (3D) scene with a sensor, and extracting features from the frame. The frame are segmented into segments, wherein each segment includes one or more features, and for each segment, searching an object map for a similar segment, and only if there is a similar segment in the object map, registering the segment in the frame with the similar segment to obtain a predicted pose of the object. The predicted poses are combined to obtain the pose of the object, which can be outputted.
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This invention relates to drilling rig equipment.
DESCRIPTION OF THE PRIOR ART
When the conventional drill pipe string is raised the drilling mud which is adherent to the outside of the drill pipe string rises with the drill pipe with which it is in contact and (a) makes difficult the handling of the drill pipe as well as (b) spilling over the floor and making footing of the operators on the floor slippery and hazardous as well as (c) being wastefull of the drilling mud liquid which currently costs about $100.00 per barrel and so is expensive.
SUMMARY OF THE INVENTION
The wiper apparatus (37) of this invention is arranged to be located and to seat on top of the rotary head structures such as a Williams Connector or Shaffer blow-out preventor (70) located on top of the casing. This apparatus (37) wipes the mud from the surface of the pipe and, also, provides a catch basin to trap objects such as wrenches and the like which might fall through the casing were it not for this wiper structure. Additionally, this wiper structure provides for damping the vibration of the drill pipe string (31) and assists the slips as (32 and 33) on the rotary table or rig derrick floor to grasp the drill pipe string and hold it in position while segments of such drill pipe string are added to or removed from the string.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an overall view of the system in which the apparatus of this invention operates.
FIG. 2 is an oblique bottom view of the ring 40 used in the apparatus 37.
FIG. 3 is a perspective overall side view of the pipe wiper apparatus 37 of this invention.
FIG. 4 is a vertical longitudinal sectional view along section 4A--4A of FIG. 7 of the apparatus 37 during the stage of operation thereof wherein the ring 40 is in its lowered position.
FIG. 5 is a longitudinal vertical section of the apparatus 37 in the position of parts thereof wherein the ring 40 is in its elevated position.
FIG. 6 is a vertical longitudinal sectional view of the apparatus 37 and neighboring parts of the system in which it works during the stage of operation of the apparatus 37 wherein it serves to damp horizontal vibration of the top of the drill string 31.
FIG. 7 is a top view looking into the chamber 47 along direction of arrow 7A of FIG. 4 and ring 40 in position shown in FIG. 4.
FIG. 8 is a bottom oblique view of the lower portion of wiper apparatus 37 as seen along direction of arrow 8A of FIG. 3.
FIG. 9 is an end view of ring 40 as seen along direction of arrow 9A of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Generally in a rotary drilling rig 18 a casing 20 extends through the below-ground strata 19 in which a bit 21 is operated. A mud pump 22 pumps drilling mud from a pit 23 through a mud hose 24 to the top of the drill pipe string to a square sectioned pipe 25 known as the kelly. The mud passes downward through the string of drill pipe 31 to the bit and thence up the casing carrying cuttings from the bit via line 17 to the mud pit. A traveling block 27 serves to raise and lower the drill pipe string 31 for replacement of the bit as needed while the string is supported on a crown block 28 at the top of the derrick 29. An engine 30 serves to operate the rotary table 26 and the draw works which raise and lower the pipe string.
The pipe wiper apparatus 37 of this invention comprises a rigid cylindrical body 38, a removable rigid cap 39, and a resilient annular ring 40.
The body 38 comprises a rigid upper cylindrical bowl 41, a rigid shell 42 of lesser diameter than the bowl 41, and a rigid rim 43 of usually larger diameter than the shell. A rigid internal guide 44 is firmly attached to the bottom edge 45 of the rim 43 and projects to a narrower circular upper edge 46. The guide 44 is flared outwardly or radially from the narrower upper smoothed edge 46 to its bottom edge 45. The upper edge 46 projects into a bowl chamber 47. Rim 43 is of a size adapted to fit into and be located in and supported on rotary head structure as 70.
The body 38 is axially symmetrical about its center through which longitudinal center each segment, as 36, of the drill pipe string 31 passes. Releasable connecting means are provided between the cap and the bowl. The inner wall of the bowl 41 is provided with a plurality of like lugs such as 48 and 48A and 48B on the top of each of which pins as 49, 50, and 51 fixed to such lugs extend through holes in the plate 54 of cap 39. The cap 39 is formed of an inner upper rigid cylindrical sleeve 63 and a lower flat circular rigid plate 54 firmly joined together and surounding an opening 55 located directly below the central hole 99 in floor 35. The plate 54 has holes as 56 therein, one for each of the lugs 49, 50, and 51. The plate 54 also supports a rigid lug 57 which engages a notch 58 in the wall 41 to align the pins as 49, 50, and 51 for location in the respective holes therefor.
The ring 40 has an outer circular edge 61, an imperforate flat smooth bottom face 62, and a central cylindrical hole 63. A smooth flat annular groove 64 is provided in the ring bottom face 62 and that groove has an inner central groove shoulder 65 and a outer or radial groove shoulder 66. The ring inner hole face 67 is cylindrical. The top face 68 of the ring 41 is imperforate, flat and the entire mass of the ring 40 is a resilient oil resistant rubber such as a urethane type of synthetic plastic. Such synthetic plastics are described in "Rubber Technology" by M. Morton (published by Van Nostrand-Reinhold Publishing Company, chapter 17, pages 440 to 458).
The ring 40 extends from the surface of the pipe string segment to radially of the upper edge 46 of the guide but does not extend radially to the inner surface of the wall of the bowl 41. To maintain the required flexibility for the wedging action below described while still having adequate surface toughness and hardness the ring 40 is preferably hollow being formed of upper and lower panels 91 and 92 and with space therebetween the panels joined by intermediate sections as 95 and 96. Holes as 93 and 94 may be provided between the section panels and intermediate sections. The uppers surface of the ring may also be provided with an annular groove 97 like the annular groove on the lower face. During the operation of the rig 18 when the drill pipe string 31 is stationary the ring 40 comes to the position shown in FIG. 4 with the hole face 67 in a close yet sliding engagement fit with the periphery of the drill pipe string surface and the flat face of groove 64 loosely engaging the top edge 46 of the guide 44. Edge 46 is smooth to not cut into the ring 40.
At the bottom end of the wall of bowl 41 is a flat ring 71 together with an upstanding annular ledge portion 72 at the top of the guide 44, they form a pocket 73. The pocket is located below the bottom surface of the ring 40 in the position of parts shown in FIG. 4. The fit of the inner hole face 67 of the ring 40 is sufficiently firm and close to the outer surface of the drill pipe string 31 as shown in FIG. 7 that tools and like hard and tough objects which may fall through the opening 36 in the drill floor 35 and rotary table thereabove, fall into the pocket 73 and may be readily recovered therefrom. However the pocket 73 is sufficiently shallow, especially in view of holes as 74, 75, and 76 near the edge 46 that the grit and dirt that also enter the pocket 73 are washed through such holes; thereby the structure of apparatus 37 avoids any accumulation of small particles that would other-wise lessen the capacity of the pocket 73 to hold large heavy debris therein until such debris might be recovered. The cap 39 is readily removed from the body 38 for purposes of locating the ring 40 in the chamber 47 and also for access to the pocket 73.
During operation of the rig when the drill pipe string is rotated and when the mud is forced upward past the guide 44, and especially when the drill pipe string is moved upward in a direction as 81 in FIG. 5, the ring 40 is moved up-ward against the plate 54 so the upper surface 68 of the ring 40 contacts the bottom surface of the plate 54 and is thereby held in position and blocks passage of drilling mud upward through the hole 99 in floor 35. The ring 40 has substantial thickness and adequate stiffness to maintain its shape in such position and at the same time has sufficient resiliency to accomodate to the change in the diameter of the string as joints thereof are pulled past the hole face 67. In such position as shown in FIG. 5 the ring 40 serves to deflect and wipe from the drill string surface mud liquor which is carried upward by the upwardly moving pipe or otherwise driven past guide 44 and guides such mud in a path as shown in 82; such path extends from the drill pipe surface and along the bottom surface 62 of the ring 40 and then into the pocket 73, through the holes as 74, 75, and 76 or over the top of ledge 72. Such action returns such mud to the interior of the casing and thence via line 17 to the mud pit and so recovers it.
Additionally the structure of the ring is such that it also serves to increase the efficiency of the holding of the slips of such drill pipe string during such time as the separate segments as 36 of the pipe string are being added to or removed from the drill pipe string.
Generally, each of the slips (as 32 and 33) have serrated or toothed central portions (as 83 and 84 respectively) which engage the drill pipe string and hold it from vertical displacement; however, such engagement usually requires a downward vertical movement of the pipe string of about between 1 and 3 inches. During such downward movement the pipe string, which string is frequently not perfectly centered, engages the inner hole face 67 of the ring 40 and causes a distortion of the ring 40 generally as shown in FIG. 6 so that the rigid initially cylindrical surface 67 is distorted into a conical shape and the ring surfaces 68 and 62 which had initially been horizontal and extended transversely to the longitudinal axis of the string, generally as shown in FIGS. 4 and 5, are then at an acute angle thereto: such shape change causes a wedging action engagement between the drill pipe string and surface 67 centrally and a like engagement between the upper lip or edge 46 of the guide 44 and surface 62 radially. Such engagements permit the downward movement of the pipe relative to such ring, as the ring itself does not hold the pipe firmly, but there is thereby provided positive resistance to movement in the horizontal plane of the portion of drill pipe string engaged by the hole face 67 of the ring 40 and by the wedging contacts of the bottom face 62 of the ring with the top edge 46 of the guide 44. Such engagement reduces lateral vibration of the pipe string for a short but critical time during the downward movement of the pipe string relative to the serrated or toothed portions of the slips as 32 and 33. The diminution of such side-ways vibration enhances the grasping capacity of the toothed or serrated portion to engage the pipe string and prevents further slippage of the pipe string downwards as might otherwise permit a further downward dropping of the pipe string and a necessary later "fishing" operation.
The lug 57 on the plate 54 provides for orientation of the cap 39 relative to the body 38 for a proper positioning of the cap on the body and a firm connection of the cap to the body. Transverse pins as 85 extend through each of the pins 49, 50 and 51 to maintain the position of the cap relative to the body 38: those pins are in turn held by chains to prevent the loss of such pins while disengaged from the pins 49, 50, and 51.
In operation, accordingly, the apparatus 37 provides for a saving of mud during the upward movement of the pipe string and recovering of such drilling mud, which is a economic saving because it avoids loss of such liquid, and provides safety benefits by avoiding foot slippage by the operators on the drilling rig floor as well as removing the drilling mud liquor so that handling of the drill pipe string segments is facilitated. Further, as shown in FIG. 4 the apparatus 37 provides for preventing loss of materials such as wrenches, large nuts and the like that might otherwise drop through the holes 36 and 55 into the space between the drill pipe and the casing and damage the bit or the pipe string during the drilling operation. Further still, as shown in FIG. 6, the apparatus 37 provides for assisting the slips in their action of grasping the string at such times as when the only support for that string is provided by the slips.
In the exemplary embodiment 37 which is made of 1/4 inch thick steel hereinabove described, the ring 40 height is 4 inches and the outside diameter is 131/2 inches. The bowl 41 has an outside diameter of 18 inches, the ledge diameter (46) is 103/4 inches and holes 74 are each 3/4 inch high and 3 inches wide. The portions of the body 38 are firmly attached together by welding. Pocket 73 is 3 inches deep. FIGS. 3 and 7 are drawn to scale and other dimensions may be approximated therefrom for that embodiment.
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The wiper apparatus of this invention is arranged to be located and to seat on top of the rotary head structures such as a Williams Connector or Shaffer blow-out preventor located on top of the casing. This apparatus wipes the mud from the surface of the pipe and, also, provides a catch basin to trap objects such as wrenches and the like which might fall through the casing were it not for this wiper structure. Additionally, this wiper structure provides for damping the vibration of the drill pipe string and assists the slips on the rotary table or rig derrick floor to grasp the drill pipe string and hold it in position while segments of such drill pipe string are added to or removed from the string.
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BACKGROUND OF THE INVENTION
The present invention relates to sampling devices, and more particularly to devices for collecting an aseptic specimen of urine.
Samples of urine must be frequently obtained from patients by physicians for purposes of analysis and possible treatment of the patients. Of course, it is desired that the urine sample be free from contamination to permit proper analysis of the sample. In the past it has been very difficult to consistently obtain an aseptic urine sample from the patient, particularly a female patient, without catheterizing the patient which is an undesirable procedure when solely to obtain the specimen.
It is known that the initial portion of the urine discharge may become contaminated as it passes through the urethra, but a later midstream portion of the discharge is believed relatively free from contamination after the initial portion of the discharge has washed the urethra during voiding. Thus, it is desirable to obtain the urine sample from the midstream portion of the discharge.
Accordingly, patients have been requested to position a container in the urine discharge only after the initial portion of the stream has been voided to capture the midstream portion of the discharge, but this procedure has been unsatisfactory. Initially, patients are reluctant to use the containers in this manner since the discharge splashes about the container and hands as the container is brought into position to receive the midstream discharge, and the physician's aides are equally reluctant to handle the wet container. Additionally, the sample may become contaminated while handling the container and passing it into the urine stream.
SUMMARY OF THE INVENTION
A principal feature of the present invention is the provision of a device for collecting a urine specimen in a simplified and aseptic manner.
The device of the present invention has a container having wall means defining a chamber and an opening communicating with the chamber. The device has liquid sampling means comprising, compressible liquid absorption means for receiving the liquid specimen, and handle means for supporting the absorption means. The device also has means for compressing the absorption means in the container chamber.
A feature of the present invention is that the patient may utilize the handle means for placing the absorption means in the midstream portion of a urine discharge.
Another feature of the present invention is that the absorption means receives and retains the midstream portion of the urine discharge.
Yet another feature of the invention is that the device permits placement of the absorption means in the discharge without splashing of the discharge against the patient's hands.
Still another feature of the invention is that the device permits placement of the absorption means in the discharge without contact of the liquid receiving portion of the device by the hands to prevent contamination of the specimen.
A further feature of the present invention is that the handle means may be utilized to place the absorption means containing the specimen into the container without contact of the absorption means and sample by the hands.
A feature of the present invention is that the compressing means releases the specimen from the absorption means into the container chamber.
Another feature of the present invention is that the specimen is released into the container chamber without contamination of the specimen.
Yet another feature of the invention is that the container may be stored for subsequent analysis of the aseptic specimen.
Another feature of the present invention is the provision of means for removing the handle means from the container for compact storage of the container.
A further feature of the invention is the provision of means for removing the specimen from the container in an aseptic manner for analysis.
Still another feature of the invention is the provision of a method for collecting an aseptic specimen from the urine discharge.
Further features will become more fully apparent in the following description of the embodiment of this invention and from the appended claims.
DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a fragmentary elevational view, partly broken away, of a specimen collecting device of the present invention;
FIG. 2 is a fragmentary elevational view, taken partly in section of the device of FIG. 1;
FIG. 3 is a perspective view of a specimen receiving part of the device of FIG. 1;
FIG. 4 is a fragmentary elevational view, partly broken away, of the device of FIG. 1 showing the specimen being released from a sponge in the device;
FIG. 5 is a fragmentary elevational view, taken partly in section, showing a handle being removed from the device;
FIG. 6 is a fragmentary perspective view, partly broken away, showing another embodiment of the specimen collecting device of the present invention;
FIG. 7 is an elevational view, taken partly in section, showing a sponge in the device being compressed to release the specimen into a container;
FIG. 8 is an elevational view, taken partly in section and partly broken away, showing another embodiment of the device of the present invention;
FIG. 9 is a fragmentary sectional view of a shaft for the device of the present invention; and
FIG. 10 is a fragmentary sectional view of a sampling port for a lid in the device of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1-3, there is shown a sterile device generally designated 20 for collecting an aseptic sample or specimen of urine. The device 20 has a container 22 having a bottom 24 and a sidewall 26 defining a sterile chamber 28, and having an opening 30 at a top 32 of the container communicating with the chamber 28. The device has a lid 34 releasably attached to the top 32 of the container 22 by cooperating threads 36, such that the lid 34 covers the container opening 30 and closes the chamber 28 when the lid is secured to the container.
The lid 34 has an aperture 38 extending through the lid to slidably receive an elongated shaft 40. When the lid 34 is secured to the container 22, the shaft 40 has an inner end 42 located in the container chamber 28, and an outer end 44 located outside the container, such that an inner portion 46 of the shaft 40 is positioned in the chamber 28 and an outer portion 48 defining a handle for the device is located outside the lid 34.
The device has a circular compression plate 50 attached to the shaft 40 adjacent its inner end 42, such that the plate 50 extends outwardly from the shaft 40. The shaft 40 has a first slot 52 extendng peripherally around the shaft 40 at a location slightly spaced from the plate 50 toward the outer end 44 of the shaft 40. In a preferred form, the width of the slot 52 is approximately equal to or slightly greater than the thickness of the lid 34 for a purpose which will be described below. The shaft 40 also has a second slot 54 extending peripherally around the shaft 40 and spaced slightly from the first slot 52 toward the outer end 44 of the shaft 40. The width of the second slot 54 is less than the thickness of the lid 34 adjacent the aperture 38.
The device has a sterile absorption member or sponge 56 retained on the shaft intermediate the plate 50 and the lid 34. The sponge 56 may be made from a compressed cellulosic material, such as a cellulose sponge sold under the name Normandy by American Sponge and Chamois Company, Inc. of Long Island City, New York. In a preferred form, the sponge 56 may have a generally cylindrical shape defining a generally centrally located bore 58 extending through the sponge 56. Before wetting, the diameter of the bore 58 is preferably of a size less than the outside diameter of the shaft 40 adjacent the slot 52, while the thickness of the sponge 56 is preferably of a size approximately equal to the width of the slot 52, such that the unwetted sponge 56 is retained in position on the shaft 40 in the slot 52. When wetted, the sponge 56 expands both laterally and longitudinally relative the shaft 40, such that lateral expansion of the sponge 56 enlarges the bore 58 to a diameter size greater than the outside diameter of the shaft 40, thus permitting expansion of the sponge 56 longitudinally along the shaft 40, as shown in FIG. 3. In a suitable example, the sponge 56 may have a thickness or length of approximately 1/8 inch (.32 cm.) before wetting, and an enlarged or expanded length approximately equal to 1 inch (2.54 cm.) when wetted. Such a sponge may contain up to twenty cubic centimeters of liquid when saturated.
Before use of the device, the shaft 40 is positioned in the lid 34 at a first inner position with the sponge 56 spaced beneath the lid and exposed for collecting the specimen, as shown in FIG. 1. In a preferred form, the plate 50 may be located adjacent the bottom 24 of the container 22, and the sponge 56 is located slightly above the plate 50. Also, in this configuration, the outer portion 48 of the shaft 40 extends a sufficient distance from the lid 34 to define a handle which may be grasped by the patient's hand. The lid 34 may be removed from the container 22 while the sample receiving part of the device is held by the handle or outer portion 48 of the shaft 40. After the patient has voided an initial part of the urine stream, in the case of a female patient while the cleansed labia is held open, the patient passes the sponge 56 into the midstream portion of the urine discharge while holding the shaft with the handle 48. The sponge 56 absorbs a sample from the midstream portion of the urine discharge while laterally and longitudinally expanding relative the shaft, as previously described. The plate 50, which is located adjacent the sponge 56, prevents splashing of the discharge against the patient during collection of the sample. After a relatively short period of time, such as five to ten seconds, the sponge 56 will have reached its enlarged configuration containing the specimen, as shown in FIG. 3, and the plate 50 and wetted sponge 56 may be inserted into the container chamber 28 through use of the handle, after which the lid may be secured to the container to close the chamber 28. Thus, the midstream portion of the urine discharge may be collected by the sponge 56 without the hands contacting the inner portion 46 of the shaft 40, the sponge 56, or the plate 50 in order to prevent contamination of the sample. Also, the sample is collected by the patient without splashing or wetting the hands, nor is the outside of the container 22 wetted by the discharge during the procedure.
With reference to FIG. 4, after the lid 34 has been secured to the container 22, the shaft 40 may be moved outwardly through the lid aperture 38 to reduce the spacing between the plate and lid, such that the wetted sponge 56 is compressed between the plate 50 and the lid 34 to release the sample in an aseptic manner into a lower part of the container chamber 28. Referring to FIG. 5, as the shaft 40 moves through the lid, the relatively small second slot 54 passes through the lid aperture 38, after which the first slot 52 receives the lid 34 and stops movement of the shaft at a second outer position of the shaft when the specimen has been substantially compressed from the sponge 56. The interengaged lid 34 and slot 52 subsequently retain the sponge in its compressed configuration intermediate the plate 50 and lid 34. As shown in FIG. 5, the handle 48 may be broken from the remainder of the shaft 40 at the second slot 54 which defines an area of weakness in the shaft 40. At this time, the aseptic sample has been collected in the lower part of the container chamber 28, and the handle 48 of the device has been removed to permit compact storage of the container and retained sample until ready for analsis when the lid 34 may be removed from the container 22 to pour the aseptic sample from the container.
Another embodiment of a shaft for the device of FIG. 1 is shown in FIG. 9, in which like reference numerals designate like parts. In this embodiment, the shaft 40 has a channel 60 of capillary dimensions extending through the shaft 40. An outer end of the channel communicates with the outside of the shaft 40 through an opening 62 which is covered by a cap 64 releasable attached to the outer end 44 of the shaft 40. An inner end of the channel 60 communicates with the container chamber through an opening 66 at the inner end 42 of the shaft 40, or, as shown in dotted lines, at a location slightly spaced from the compression plate 50 toward the shaft end 44. With reference to FIGS. 5 and 9, when the lid has been received in the first slot 52 of the shaft 40, the sample may be obtained from the container in the following manner. The cap 64 may be removed from the outer end 44 of the shaft 40, and the container may be inverted to a position with the outer end portion 48 of the shaft 40 located below the lid, such that the sample collects above the lid in the chamber and drains through the opening 66, the channel 60, and the opening 62 where it may be received for analysis.
Another embodiment of the device of the present invention is illustrated in FIGS. 6 and 7, in which like reference numerals designate like parts. In this embodiment, the device 20 has a sponge 56 retained on a shaft 40 by suitable means, such as by a slot in the shaft. The shaft 40 is secured to the lid at a fixed position such that the shaft 40 extends through the lid aperture 38 to define a handle 48 and an inner end portion 46. As shown, the container sidewall 26 has a ledge 70 extending peripherally around the inside of the container 22 in the chamber 28. The compression plate 50 extends laterally across the inside of the container and is supported by the ledge 70 at a position in the upper part of the chamber spaced from the lid 34 when the lid is secured to the container 22, with the distance between the retained plate 50 and the attached lid 34 being considerably less than the length of the wetted sponge 56 on the shaft 40. The plate 50 has an aperture 72 aligned with the shaft 40 to receive the inner end 42 of the shaft 40 when the lid 34 is secured to the top 32 of the container 22. Also, the plate 50 has a plurality of radial ribs 74 defining a plurality of openings 76 extending through the plate 50.
After the midstream urine sample has been absorbed in the sponge 56, the inner end 42 of the shaft 40 may be positioned in the plate aperture, and the lid may be moved toward the top 32 of the container 22 and secured in place on the container. During this time, the wetted sponge 56 is compressed between the plate 50 and the lid 34 to release the aseptic sample from the sponge 56. The sample passes from the sponge through the openings 76 to a lower part of the chamber 28 for collection. If desired, the lid 34 may be removed from the container 22, and the sample may be poured from the container for analysis.
Another embodiment of the device 20 of the present invention is illustrated in FIG. 8, in which like reference numerals designate like parts. In this embodiment, the shaft 40 has a channel 78 extending from the inner end 42 of the shaft 40 to a location spaced from the outer end 44 of the shaft 40 in order to define a closed outer end of the shaft, as shown. The shaft 40 has a peripheral slot 80 outside the lid defining an area of weakness adjacent the channel 78. When it is desired to remove the sample from the container chamber 28, an outer section of the shaft 40 may be broken at the slot 80 to expose the channel 78, after which a pipet may be passed through the remaining portion of the channel 78 to the lower part of the chamber in order to withdraw a sample with the pipet. Of course, a shaft 40 of the type shown in FIG. 9 may be utilized for a similar purpose by making the size of the channel 60 sufficiently large to receive the pipet; the cap 64 may be removed from the outer end 44 of the shaft 40 to permit placement of the pipet in the shaft channel 60. Referring again to FIG. 8, the plate 50 may have a depending base 82 to support the plate 50 at a position spaced from the bottom 24 of the container 22.
With reference to FIG. 10, the lid 34 may have an outwardly directed tubular extension 84 defining a port 86, and a cap 88 removably secured to the extension 84. When it is desired to obtain the sample from the container chamber, the cap 88 may be removed from the extension 84, and a pipet may be passed through the port 86 to withdraw the sample from the lower part of the container chamber.
According to a method of the invention, a sterile compressible absorbent member is positioned in a urine discharge to absorb a portion of the discharge. The absorbent member is then compressed by a sterile surface positioned to release an aseptic sample from the absorbent member into the sterile chamber of the container.
The foregoing detailed description is given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications will be obvious to those skilled in the art.
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A device for collecting aseptic liquid specimens comprising, a container having wall means defining a chamber and an opening communicating with the chamber. The device has liquid sampling means comprising, compressible liquid absorption means for receiving the liquid specimen, and handle means for supporting the absorption means while receiving the specimen and placing the specimen containing absorption means in the chamber through the container opening. The device has means for compressing the absorption means in the container chamber to release the specimen into the chamber.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of application Ser. No. 09/012,113, filed Jan. 22, 1998, pending, which is a continuation of application Ser. No. 09/441,238, filed Nov. 16, 1999, pending.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to providing die interconnection within a semiconductor die and, more specifically, to a method and apparatus for routing die interconnections for accessing selected functional segments located on an integrated circuit semiconductor die.
[0004] 2. State of the Art
[0005] A typical integrated circuit (IC) or semiconductor die includes external connection points termed “bond pads” that are in electrical communication with integrated circuits formed on the active surface of the semiconductor die. The bond pads are used to provide electrical connection between the integrated circuits and external devices, such as a lead frame or a printed circuit board. The bond pads also provide sites for electrical testing of the die, typically by contact with probes, which send and receive signals to and from the die to evaluate the functionality of the die.
[0006] In a conventional semiconductor die and lead frame assembly, the semiconductor die is attached to a die paddle of a lead frame using an adhesively coated tape or an adhesive, in some instances. The bond pads formed on the active surface (face) of the die are typically electrically and mechanically attached to lead fingers of a lead frame either terminating adjacent the periphery of the semiconductor die, if it is a conventional lead frame, or adjacent the center of the semiconductor die, if it is a lead-over-chip type lead frame, using bonding wires of gold, aluminum or other metals or alloys thereof.
[0007] Wire bonding is typically a process through which some or all of the bond pads formed on the active surface of the die are connected to the lead fingers or buses of a lead frame by metal bonding wires. The bonding wires comprise the electrical bridge between the bond pads and the leads of the packaged integrated circuit. A wire bonding apparatus bonds the bonding wires to the bond pads and to the lead fingers of the lead frame, typically using heat and pressure, as well as ultrasonic vibrations in some instances. Following wire bonding, the lead frame and die are typically encapsulated in a suitable plastic (particle-filled polymer) or, in some instances, packaged in a preformed ceramic or metal package. After encapsulation, the lead fingers of the lead frame are trimmed and configured to form the desired external leads of a completed semiconductor package in what is termed a “trim and form” operation.
[0008] It is often desirable to interconnect various bond pads on a single semiconductor die in order to alter the input or output functionality, or both, of the semiconductor die, such as when it is necessary to “wire around” defective portions of a semiconductor die that are only partially functional. For example, a 16 megabit DRAM memory die may only demonstrate 11 megabits of functional memory under electrical testing and burn in. Alternatively, it may be desirable for a semiconductor die having a given input/output (I/O) bond pad configuration to “look” to a particular lead frame or carrier substrate as if it were configured differently so that the semiconductor die could be used with a lead frame for which it was not originally intended. Such “wire around” functions, where possible, are typically accomplished by interconnecting bond pads on the semiconductor die through external circuitry in printed circuit boards or other carrier substrate to which the semiconductor die is mounted. Where the desired input or output, or both, functionality configuration varies from one semiconductor die to another, a separately configured printed circuit board or other carrier substrate must be provided for each desired input or output, or both, functional configuration. Thus, it would be desirable to provide a relatively easy way of interconnecting selected bond pads on a single integrated circuit semiconductor die without requiring the use of external circuitry imprinted circuit boards and other carrier substrates.
[0009] One solution has been to add electrically isolated intermediate connection elements or wire bondable jumper pads attached to the active surface of the die. These bondable jumper pads are electrically isolated from the external circuitry and from the circuitry of the semiconductor die, but for wire bonds extending to or from, or both, the bondable jumper pad. More specifically, each bondable jumper pad is not directly electrically connected to the internal circuitry of the semiconductor die, unlike the bond pad, but provides a “stepping stone” for wire bonds between bond pads of the semiconductor die or between a bond pad and a conductor external to the semiconductor die. Thus, a relatively short wire bond can be formed from a bond pad to the jumper pad and another relatively short wire bond from the jumper pad to another bond pad (or external conductor) forming an electrical connection between the bond pads (or bond pad and external conductor).
[0010] In another solution, a plurality of jumper pads is provided over the active surface of the semiconductor die, thus providing various serial jump points for a plurality of wire bonds to be formed in series between a plurality of bond pads. Where the semiconductor die has bond pads located about a peripheral edge of the active surface, a grid or array of jumper pads may be provided proximate the center of the active surface and at least partially bounded by the periphery bond pads.
[0011] Although these bonding pads are provided as alternative interconnections to provide wire around defective portions, additional functionality is desired to be accessed with various options being implemented on an integrated circuit semiconductor die. In certain situations, it is desirable to modify various circuits on the integrated circuit semiconductor die in such a way as to achieve a particular result. For example, in FIG. 1, a circuit design 2 is depicted that includes a regulator 4 . Regulator 4 can be optioned in for a 5 volt (V) application and, with the addition of a metal masking step, can be optioned out for a 3.3 V application. Regulator 4 is tied to the gate of a field effect transistor 6 , which is utilized as a pass device, that is controlling an external V CCX power signal and an internally regulated V CCR power signal. With a metal masking step 9 , or a fuse integrated into the integrated circuit, regulator 4 can be bypassed as is shown in FIG. 2. Through the use of a fuse option or the metal mask 9 option, the gate of transistor 6 is hard wired at node 8 to V SS , and metal mask 9 is still used to short the source and drain of field effect transistor 6 in order to avoid a voltage drop of several hundred millivolts across the transistor 6 .
[0012] In another situation, as shown in FIG. 3, there is an assembly limitation of the number of bonds that could be made to a single lead finger for a particular design lead frame. FIG. 3 shows a plurality of lead fingers 12 that is aligned on the perimeter of a particular semiconductor die 10 . The lead fingers 12 are connected to a portion of the plurality of bonding pads 14 , where multiple pads are bonded to particular lead fingers 12 . For example, such as illustrated in FIG. 2 where a design would require multiple connections between V CC and V SS to be bonded multiple times, a limited number of pins are available. Thus, it would be desirable to interconnect selected bond pads 14 on a single integrated semiconductor die without requiring the use of external circuitry in printed circuit boards and other carrier substrates or extraneous masking steps dedicated solely for element interconnection apart from other masking steps.
BRIEF SUMMARY OF THE INVENTION
[0013] According to the present invention, a semiconductor device is disclosed that includes a die having an active surface bearing integrated circuitry, the die includes a plurality of bond pads thereon connected to the integrated circuitry. At least one electrically conductive wire bond is made between first and second bond pads of the plurality of bond pads for providing external electrical connection between the two bond pads, which are not interconnected via the integrated circuitry within the die. The first bond pad can be a lead finger on the active surface and the second bond pad can be an option bond pad electrically connected to a third bond pad selected from the plurality of bond pads on the active surface via the integrated circuitry. Further, the third bond pad can connect to a fourth bond pad selected from the plurality of bond pads via a wire bond. The first bond pad can also be an internal voltage line and the second bond pad is an external voltage line or the bond pads can be different internal buses within the integrated circuitry.
[0014] The semiconductor device can be fabricated in any type of processing or memory device desired. As a processing or memory device, the bonding structure can be utilized in a computer system having an input and output device, as well as a central processing unit. A method is also disclosed that selects the appropriate bond pads and then provides the external electrical connection.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0015] [0015]FIG. 1 is a prior art diagram of a voltage regulator having an external and internal connection;
[0016] [0016]FIG. 2 is a prior art diagram of a process for shorting the external and internal connections of the regulator according to FIG. 1;
[0017] [0017]FIG. 3 is a prior art diagram of a plurality of bond pads used to connect to a given number of lead fingers of a lead frame having assembly limitation;
[0018] [0018]FIG. 4A illustrates in a top view the additional option pads according to the present invention;
[0019] [0019]FIG. 4B illustrates in a side view the additional option pads according to the present invention;
[0020] [0020]FIG. 5 depicts a wiring scheme using the bond pads of FIG. 4;
[0021] [0021]FIGS. 6A and 6B illustrate an alternative wiring scheme of the bond pads according to the present invention;
[0022] [0022]FIG. 7 is a top view of a semiconductor wafer comprising a plurality of the semiconductor device illustrated in FIGS. 4A and 4B; and
[0023] [0023]FIG. 8 is a block diagram of an electronic system incorporating the semiconductor device of FIGS. 4A and 4B.
DETAILED DESCRIPTION OF THE INVENTION
[0024] A semiconductor device 20 is illustrated in FIGS. 4A and 4B. Semiconductor device 20 includes a semiconductor die 22 of generally rectangular configuration. The semiconductor die 22 has an active surface 24 carrying a plurality of bond pads 26 proximate its perimeter 28 and a plurality of functional option pads 30 , distinguished by surface shading in the drawing and disposed between the rows of peripheral bonds pads 26 . The bond pads 26 are formed as an integral part of die 22 , making contact with and providing an external contact for internal circuitry (not shown) contained within the semiconductor die 22 , as is known in the art.
[0025] These particular option pads 30 are manufactured during the same processing step as that for the bonding pads and are added to provide for selected functionality based upon the wiring step to be performed later. For example, as was shown in prior art FIG. 1, it is necessary at times to tie the V CCX power source with the internally regulated V CCR power line. Thus, in FIG. 4A, extra V CC pads 30 are provided that allow additional connection between the external V CCX and the internal V CCR contacts. Since option pads 30 are processed at the same time that peripheral bond pads 26 are added and processed, the subsequent masking step required in FIG. 1, or the fuse implementation, is eliminated, thus saving time and materials during processing.
[0026] [0026]FIG. 5 illustrates how the wire bonds are formed between pads that are to be interconnected. As illustrated, wire bonds 32 , 34 , and 36 are connected between the various bond pads. In this example, wire bond 32 connects V CCX pad 30 with V CCR pad 30 . Wire bond 34 connects V CCX pad 30 to V CC pad 26 . Wire bond 36 connects another pad 26 to a different option pad 30 . Other bonding schemes are possible according to the needs of the user. The termination points of wire bonds 32 , 34 , and 36 can be a ball, wedge or other configuration as is known in the art and formed with a conventional wire bonding machine. Accordingly, a large number of input/output (I/O) alternative configurations can be achieved for any semiconductor device, depending on the number and layout of jumper pads and the configuration of wire bonds. The wire bonds are typically formed of small diameter wire material, such as, for example, small diameter wire of gold, aluminum, silver or other known materials and alloys thereof used in the art.
[0027] [0027]FIG. 6A depicts how multiple options pads 30 can be interconnected in such a fashion that a single wire bond or reduced number of wire bonds are made to outlying lead fingers 40 of a lead frame, which overcomes the interconnection problems described in the prior art with respect to FIG. 2. This is useful when there is an assembly limitation on the number of wire bonds that can be made to a single lead finger of a lead frame for a particular semiconductor die and lead frame design. Again, this is seen in designs that require the V CC and the V SS to be bonded multiple times, but the scope of the invention is not limited to those particular pins. The present invention may be used with any other bond pads of semiconductor dice that require multiple lead connections.
[0028] In FIG. 6A, and further shown in enlarged view in FIG. 6B, the V CC connection with lead finger 40 is made to several option pads 30 ; for example, option pads 30 may be V CCR and V CCX , thus relaxing the assembly requirements. Additionally, an advantage in using multiple option pads 30 is that if during the wire bonding process any shorts occur accidentally, such as shorts between wire bond 34 and wire bond 32 , there is no harm as the wires being shorted together have the same potential.
[0029] The use of the multiple bonding pads reduces the cost of manufacturing in that an additional metal mask step has been eliminated. This occurs by providing the same function by merely shorting across the pass device. Additionally, throughput is increased during the fabrication operation. Specifically, this occurs because of limiting the run to only one metal mask during fabrication for such operations as when differing voltage potentials are designed. For example, if a 3.3 volt (V) design is preferred over a 5 V design, the actual implementation on the same die can be made during the bonding process rather than adding a separate metal mask and step to provide the desired functionality. This allows the designer to defer the decision of selecting functions until during the assembly portion of the die manufacturing process and to even defer the decision until probe or test, depending upon whether laser fuse or antifuse devices are used to tie the gate of the past device to the appropriate voltage. Also, in designs that require multiple V CC or V SS to be bonded and where there is an assembly limitation on the number of bonds possible, the additional bonding pads with wire interconnection overcome the limitation of the number of bonds by interconnecting the bonding pads before making one or a small number of actual bonds to a given lead finger.
[0030] Those skilled in the art will appreciate that semiconductor devices according to the present invention may comprise an integrated circuit die employed for storing or processing digital information, including, for example, a Dynamic Random Access Memory (DRAM) integrated circuit die, a Static Random Access Memory (SRAM) integrated circuit die, a Synchronous Graphics Random Access Memory (SGRAM) integrated circuit die, a Programmable Read-Only Memory (PROM) integrated circuit die, an Electrically Erasable PROM (EEPROM) integrated circuit die, a flash memory die and a microprocessor die, and that the present invention includes such devices within its scope. In addition, it will be understood that the shape, size, and configuration of bond pads, jumper pads, dice, and lead frames may be varied without departing from the scope of the invention and appended claims. For example, the jumper pads may be round, oblong, hemispherical or variously shaped and sized so long as the jumper pads provide enough surface area to accept attachment of one or more wire bonds thereto. In addition, the bond pads may be positioned at any location on the active surface of the die.
[0031] As shown in FIG. 7, a semiconductor wafer 620 incorporates a plurality of integrated circuit devices 20 (shown in increased scale and reduced numbers relative to the wafer 620 ) of FIGS. 4A and 4B. Also, as shown in FIG. 8, an electronic system 130 includes an input device 132 and an output device 134 coupled to a processor device 136 which, in turn, is coupled to a memory device 138 incorporating the exemplary integrated circuit devices 20 of FIGS. 4A and 4B.
[0032] Accordingly, the claims appended hereto are written to encompass all semiconductor devices including those mentioned. Those skilled in the art will also appreciate that various combinations and obvious modifications of the preferred embodiments may be made without departing from the spirit of this invention and the scope of the accompanying claims.
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A semiconductor device is disclosed that includes a die having an active surface bearing integrated circuitry, the die including a plurality of bond pads thereon at least some of which are connected to the integrated circuitry and having at least one electrically conductive wire bond made between first and second bond pads of the plurality of bond pads for providing external electrical connection between the two bond pads.
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[0001] The application is a Patent Cooperation Treaty application which claims the benefit of U.S.C. §119 based on the priority of U.S. Provisional Patent Application No. 61/784,267 filed Mar. 14, 2013 which is incorporated herein by reference in its entirety.
FIELD
[0002] The present disclosure relates to compositions and methods useful in reducing excessive adiposity and treating or preventing obesity and obesity-related conditions.
BACKGROUND
[0003] Excessive adiposity is a risk factor for many chronic diseases, including type 2 diabetes mellitus (T2DM), cardiovascular disease, and cancer (Wang, McPherson et al. 2011). Studies have shown that even a modest reduction in weight has a positive impact on cardiovascular risk factors (Blackburn 1995; Pi-Sunyer 1996) and is associated with a reduced risk for both developing T2DM and diabetes-associated complications (Bosello, Armellini et al. 1997).
[0004] Lifestyle interventions aimed at reducing calories and increasing physical activity through behavioral changes are currently recommended as the first-line approach for weight management. However, these strategies alone are less successful when compared to pharmacological interventions for maintained weight loss (6 to 12 months) (Gray, Cooper et al. 2012). Unfortunately, most of the drugs approved for the treatment of obesity have been withdrawn from use due to their side effects (Gray, Cooper et al. 2012). Recently, targeting of gut hormones for the treatment of obesity has garnered interest (Neary and Batterham 2009). Indeed, infusion of glucagon-like peptide 1 (GLP-1) and peptide YY (PYY) are able to reduce appetite by acting on feeding regions of the brain in humans (De Silva, Salem et al. 2011). Another promising candidate is the stomach-derived peptide hormone ghrelin. Ghrelin levels peak in circulation during energy depleted states leading to activation of the appetite stimulating neuropeptide Y (NPY) and Agouti gene-related peptide (AgRP) neurons within the arcuate nucleus of the hypothalamus (Nakazato, Murakami et al. 2001). This action occurs via ghrelin binding to the growth hormone secretagogue receptor (GHS-R1a) (Kamegai, Tamura et al. 2000). In addition to appetite, ghrelin promotes the differentiation of adipocytes and the preference for storage of calories in adipose tissue (Tschop, Smiley et al. 2000; Rodriguez, Gomez-Ambrosi et al. 2009).
[0005] The ghrelin peptide is derived from proghrelin, which is a precursor peptide proteolytically cleaved to produce acylated ghrelin (AG) (Zhu, Cao et al. 2006), unacylated ghrelin (UAG) (Zhu, Cao et al. 2006) and obestatin (Zhang, Ren et al. 2005). However, in vitro studies have shown that both UAG (Kojima, Hosoda et al. 1999) and obestatin (Zhang, Ren et al. 2005) are unable to bind to GHS-R1a. The GHS-R1a is a G-protein-coupled receptor (Howard, Feighner et al. 1996), and is activated through the binding of its only known endogenous ligand, AG (Kojima, Hosoda et al. 1999). A recent study suggested that AG binds to GHS-R1a in the second extracellular loop (EC2), which forms a hydrophobic pocket, allowing the lipophylic acylated side chain of ghrelin to be stabilized during the binding (Pedretti, Villa et al. 2006).
SUMMARY
[0006] The present inventors have shown that in vivo expression of GHS-R1a fusion construct containing the N-terminal and extracellular binding loops 1 and 2 (GHSR/Fc) caused a reduction in AG but, interestingly, not UAG levels, and protected mice from high fat diet induced weight gain, which was associated with altered adipose gene expression profile and improved glucose clearance and insulin sensitivity. These observations suggest that the GHSR/Fc fusion construct may find clinical use in treating obesity and obesity-related conditions.
[0007] Accordingly, in one aspect, the present disclosure provides a soluble fusion molecule comprising (a) at least one of i) the N-terminal, ii) extracellular loop 1 and ii) extracellular loop 2, of the growth hormone secretagogue receptor (GHS-R1a); linked to (b) a fusion partner.
[0008] In an embodiment, the soluble fusion molecule comprises at least two of i) the N-terminal, ii) the extracellular loop 1 and ii) the extracellular loop 2 of the GHS-R1a, linked to a fusion partner. In another embodiment, the soluble fusion molecule comprises i) the N-terminal, ii) the extracellular loop 1 and iii) the extracellular loop 2 of the GHS-R1a, linked to a fusion partner. In yet a further embodiment, the soluble fusion molecule consists of i) the N-terminal, ii) the extracellular loop 1and iii) the extracellular loop 2 of the GHS-R1a, linked to a fusion partner.
[0009] In one embodiment, the N-terminal region of the GHS-R1a has the amino acid sequence as shown in SEQ ID NO:4 or 13 or a variant thereof; the extracellular loop 1 has the amino acid sequence as shown in SEQ ID NO:6 or 15 or a variant thereof; and/or the extracellular loop 2 has the amino acid sequence as shown in SEQ ID NO:8 or 17 or a variant thereof.
[0010] In another embodiment, the N-terminal region of the GHS-R1a is encoded by the nucleic acid sequence as shown in SEQ ID NO:3 or 12 or a variant thereof; the extracellular loop 1 is encoded by the nucleic acid sequence as shown in SEQ ID NO:5 or 14 or a variant thereof; and/or the extracellular loop 2 is encoded by the nucleic acid sequence as shown in SEQ ID NO:7 or 16 or a variant thereof.
[0011] In an embodiment, the fusion partner is a stabilizing molecule, such as a stabilizing protein or a polymer. In one embodiment, the stabilizing protein is an immunoglobulin constant region (Fc) or an albumin protein. In an embodiment, the Fc region is an IgG Fc region, optionally IgG2 or IgG4. In another embodiment, the stabilizing polymer is a polyethylene glycol.
[0012] The soluble fusion molecule of the present disclosure can be linked directly or can comprise a peptide linker between more than one extracellular GHS-R1a domain and/or between the GHS-R1a extracellular domain(s) and the fusion partner.
[0013] In one embodiment, the soluble fusion molecule has the amino acid sequence as shown in SEQ ID NO:2 or 11 or a variant thereof or is encoded by the nucleic acid sequence as shown in SEQ ID NO:1 or 10 or a variant thereof.
[0014] Also provided herein is a nucleic acid molecule encoding a soluble fusion molecule of the present disclosure, wherein a) and b) are proteins, optionally linked by a peptide linker.
[0015] In another embodiment, the present disclosure provides an isolated nucleic acid molecule encoding the N-terminal domain of GHS-R1a. In one embodiment, the isolated nucleic acid comprises the nucleic acid sequence as shown in SEQ ID NO:3 or 12 or encodes the amino acid sequence as shown in SEQ ID NO:4 or 13. In another embodiment, the present disclosure provides an isolated nucleic acid molecule encoding the extracellular loop 1 of GHS-R1a. In one embodiment, the isolated nucleic acid comprises the nucleic acid sequence as shown in SEQ ID NO:5 or 14 or a variant thereof or encodes the amino acid sequence as shown in SEQ ID NO:6 or 15 or a variant thereof. Further provided herein is an isolated nucleic acid molecule encoding the extracellular loop 2 of GHS-R1a. In one embodiment, the isolated nucleic acid comprises the nucleic acid sequence as shown in SEQ ID NO:7 or 16 or a variant thereof or encodes the amino acid sequence as shown in SEQ ID NO:8or 17 or a variant thereof.
[0016] Also provided is a host cell comprising a nucleic acid molecule of the disclosure.
[0017] Even further provided is a composition, optionally a pharmaceutical composition comprising a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a), and a carrier optionally a pharmaceutically acceptable carrier. In an embodiment, the GHS-R1a extracellular domain is selected from the N-terminal region, the extracellular loop 1 and/or the extracellular loop 2 or a combination thereof. In another embodiment, the GHS-R1a extracellular domain is the extracellular loop 1 and/or 2.
[0018] In another aspect, the present disclosure provides a method of reducing excessive adiposity in an animal comprising administering a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) to the animal in need thereof. Also provided is a use of a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) for reducing excessive adiposity in an animal in need thereof. Further provided is a use of a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) in the manufacture of a medicament for reducing excessive adiposity in an animal in need thereof. Even further provided is a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) for use in reducing excessive adiposity in an animal in need thereof. In an embodiment, the GHS-R1a extracellular domain is selected from the N-terminal region, the extracellular loop 1 and/or the extracellular loop 2 or a combination thereof. In another embodiment, the GHS-R1a extracellular domain is the extracellular loop 2.
[0019] In one embodiment, the present disclosure provide a method of reducing weight gain in an animal comprising administering a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) to the animal in need thereof. Also provided is use of a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) for reducing weight gain in an animal in need thereof. Further provided is use of a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) in the manufacture of a medicament for reducing weight gain in an animal in need thereof. Even further provided is a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) for use in reducing weight gain in an animal in need thereof. In an embodiment, the GHS-R1a extracellular domain is selected from the N-terminal region, the extracellular loop 1 and/or the extracellular loop 2 or a combination thereof. In another embodiment, the GHS-R1a extracellular domain is the extracellular loop 2.
[0020] In another embodiment, the present disclosure provides a method of treating obesity or an obesity-related condition in an animal comprising administering a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) to the animal in need thereof. Also provided is a use of a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) for treating obesity or an obesity-related condition in an animal in need thereof. Further provided is a use of a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) in the manufacture of a medicament for treating obesity or an obesity-related condition in an animal in need thereof. Even further provided is a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) for use in treating obesity or an obesity-related condition in an animal in need thereof. In an embodiment, the GHS-R1a extracellular domain is selected from the N-terminal region, the extracellular loop 1 and/or the extracellular loop 2 or a combination thereof. In another embodiment, the GHS-R1a extracellular domain is the extracellular loop 2.
[0021] In one embodiment, the obesity-related condition is type 2 diabetes, cardiovascular disease or cancer. Among the types of cancer most strongly linked to obesity are esophagus, breast, endometrium, colorectal and pancreas. Accordingly, in an embodiment, the cancer is cancer of the esophagus, breast, endometrium, colorectal and pancreas. In another embodiment, the obesity-related condition is high cholesterol, high triglycerides, high blood pressure metabolic syndrome (a combination of high blood sugar, high blood pressure, high triglycerides and high cholesterol) or polycystic ovarian syndrome (PCOS).
[0022] In yet a further embodiment, the present disclosure provides a method of improving glucose tolerance and/or insulin sensitivity in an animal comprising administering a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) to the animal in need thereof. Also provided is a use of a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) for improving glucose tolerance and/or insulin sensitivity in an animal in need thereof. Further provided is use of a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) in the manufacture of a medicament for improving glucose tolerance and/or insulin sensitivity in an animal in need thereof. Even further provided is a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) for use in improving glucose tolerance and/or insulin sensitivity in an animal in need thereof. In an embodiment, the GHS-R1a extracellular domain is selected from the N-terminal region, the extracellular loop 1 and/or the extracellular loop 2 or a combination thereof. In another embodiment, the GHS-R1a extracellular domain is the extracellular loop 2.
[0023] The animal may be any animal, optionally humans. In one embodiment, the animal has Type 2 diabetes.
[0024] Other features and advantages of the present disclosure will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples while indicating embodiments of the disclosure are given by way of illustration only, since various changes and modifications within the spirit and scope of the disclosure will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The disclosure will now be described in relation to the drawings in which:
[0026] FIG. 1 shows the validation of GHSR related constructs. Illustration of the full length (WT) and extracellular domain (GHSR/Fc) constructs (A). Domains are identified as N-terminal (Nt), extracellular domain 1 and 2 (EC1, EC2) and mouse immunoglobulin IgG1 constant region (Fc). Western blots were performed using anti-Myc tag antibody for immunoblotting of cell lysates (L) and culture media (M) from L6 cells (B), and CHO (C) cells transfected with GHSR/Fc based constructs. Fluorescent immunocytochemistry using anti-mouse IgG-Fc was conducted in L6 muscle cells transfected with WT and GHSR/Fc plasmids (D, transfected cells appear gray in the Figure).
[0027] FIG. 2 shows the effect of GHSR/Fc on weight gain and metabolic parameters. Mice received three intramuscular injections of indicated plasmids, and were placed on a high fat diet (HFD) the second day after the first gene transfer. The body weight was monitored during the feeding course (A).
[0028] FIG. 3 shows western blots performed using anti-Myc tag antibody for immunoblotting gastrocnemius muscle tissue lysate (A) and blood plasma (B) at the end of the study. Circulating levels of total (AG and UAG), acyl specific (AG) (C) and IGF-1 (D) were assayed at the end of the study. Data are Mean±SEM, *P<0.05.
[0029] FIG. 4 shows the effect of GHSR/Fc on adipose tissue. Post experimentally, peritoneal fat pads were observed from sacrificed GHSR/Fc treated and control mice (A). Fat pad mass (B) and gastrocnemius muscle mass (C) were quantified for indicated stores in GHSR/Fc and control mice (B). mRNA Transcripts levels of leptin, hormone sensitive lipase (HSL), PPARγ, interleukin-1 (IL-1) and tumor necrosis factor a (TNFα) were quantified by real time RT-PCR relative to 18S ribosomal RNA using the standard curve method (D). Data are Mean±SEM, *P<0.05, **p<.001, (n=5).
[0030] FIG. 5 shows intra-peritoneal glucose and insulin tolerance tests. Glucose tolerance test (IPGTT) were performed either prior to HFD feeding and before the metabolic cage assay (A). The area under the curve (AUC) for the glucose tolerance test was compared between GHSR/Fc and control mice (B). Insulin tolerance test (ITT) was conducted at the day before sacrifice of the mice (C), and (AUC) is shown (D). Data are Mean±SE, *P<0.05, ***p<.0001, (n=5).
DETAILED DESCRIPTION
[0031] The present inventors developed GHS-R1a-fusion constructs of a decoy protein containing the ligand-binding domains of the ghrelin receptor. Intramuscular injection of the GHSR/Fc plasmid decreased circulating levels of acylated-ghrelin. Upon challenge with high fat diet (HFD), treated mice displayed reduced weight gain compared to controls, which is associated with reduced fat accumulation in the peritoneum but not lean mass. Quantitative RT-PCR showed increased PPARγ and hormone sensitive lipase transcripts levels in adipose tissue of treated animals, illustrating a preference for increased fat utilization. Intraperitoneal glucose tolerance and insulin tolerance tests showed improved glucose clearance and insulin sensitivity in GHSR/Fc-treated animals. Thus, in vivo expression of the GHSR-based fusion protein prevents diet-induced weight gain, altering adipose gene expression and improving glucose tolerance.
[0032] The present inventors have shown that in vivo expression of GHS-R1a fusion construct containing the extracellular binding loops 1 and 2 (GHSR/Fc) caused a reduction in acylated ghrelin (AG) but, interestingly, not unacylated ghrelin (UAG) levels, and protected mice from high fat diet-induced weight gain, which was associated with altered adipose gene expression profile and improved glucose clearance and insulin sensitivity. These observations suggest that the GHSR/Fc fusion construct may find clinical use in treating obesity and obesity-related conditions.
[0033] Accordingly, in one aspect, the present disclosure provides a soluble fusion molecule comprising (a) at least one of i) the N-terminal, ii) extracellular loop 1 and iii) extracellular loop 2, of the growth hormone secretagogue receptor (GHS-R1a); linked to (b) a fusion partner.
[0034] The term “growth hormone secretagogue receptor” or “GHS-R1a” refers to the full length growth hormone secretagogue receptor from any species or source, optionally mammalian, such as human or mouse and isoforms and homologs thereof. Such receptors have both extracellular and intracellular domains including when folded properly as in FIG. 1A an N-terminal domain (NTD), three extracellular loops (EC1, EC2 and EC3) and transmembrane domains. The nucleotide sequence of human GHS-R1a is as shown in SEQ ID NO: 18 and encodes the human GHS-R1a protein under Genbank Accession No. Q92847 The nucleotide sequence of murine GHS-R1a is as shown in SEQ ID NO:9 and encodes the murine GHS-R1a protein under Genbank Accession No. Q99P50.
[0035] The term “extracellular domain of GHS-R1a” refers to a domain of the GHS-R1a receptor that lacks the transmembrane and intracellular domains of the receptor, and includes, without limitation, the N-terminal domain, the extracellular loop 1 and the extracellular loop 2.
[0036] The term “N-terminal” as used herein refers to an isolated peptide corresponding to the amino acid sequence coding for the N-terminal extracellular region of GHS-R1a. In an embodiment, the N-terminal domain extends to the last amino acid of the extracellular domain preceding the transmembrane domain amino acid sequence.
[0037] The term “extracellular loop” as used herein refers to an isolated protein comprising the sequence of a portion of the GHS-R1a that forms a loop on the extracellular side of the cell membrane. GHS-R1a has a first extracellular loop from 102 to 127 amino acids of human GHS-R1a and from 101 to 126 amino acids of mouse GHS-R1a, termed extracellular loop 1, and a second extracellular loop from 182 to 207 amino acids of human GHS-R1a and from 181 to 206 amino acids of mouse GHS-R1a, termed extracellular loop 2.
[0038] In an embodiment, the fusion molecule comprises at least two of i) the N-terminal, ii) the extracellular loop 1 and ii) the extracellular loop 2 of the GHS-R1a, linked to a fusion partner. In another embodiment, the fusion molecule comprises i) the N-terminal, ii) the extracellular loop 1 and iii) the extracellular loop 2 of the GHS-R1a, linked to a fusion partner. In yet a further embodiment, the fusion molecule consists of i) the N-terminal, ii) the extracellular loop 1 and iii) the extracellular loop 2 of the GHS-R1a, linked to a fusion partner.
[0039] In one embodiment, the N-terminal region of the GHS-R1a has the amino acid sequence as shown in SEQ ID NO:4 or 13 or a variant thereof or is encoded by the nucleic acid sequence as shown in SEQ ID NO:3 or 12 or a variant thereof; the extracellular loop 1 has the amino acid sequence as shown in SEQ ID NO:6 or 15 or a variant thereof or is encoded by the nucleic acid sequence as shown in SEQ ID NO:5 or 14 or a variant thereof; and/or the extracellular loop 2 has the amino acid sequence as shown in SEQ ID NO:8 or 17 or a variant thereof or is encoded by the nucleic acid sequence as shown in SEQ ID NO:7 or 16 or a variant thereof.
[0040] The term “a fusion molecule” refers to the linking of a peptide sequence derived from the extracellular domain or domains of GHS-R1a to a fusion partner and can be a direct or indirect linkage via a covalent or non-covalent linkage. The fusion partner may be linked to either the N-terminus or the C-terminus of the peptide sequence derived from GHS-R1a.
[0041] The term “soluble fusion molecule” as used herein refers to the fusion molecule as lacking any transmembrane or intracellular domains and if expressed from a nucleotide sequence in a cell, would be a secreted protein.
[0042] In an embodiment, the fusion partner is a stabilizing molecule, such as a stabilizing protein or a polymer.
[0043] The term “stabilizing molecule” as used herein refers to a molecule that when linked to the extracellular domain(s) provides an increased half-life and/or reduced immunogenicity compared to the extracellular domain(s) without such molecule.
[0044] In one embodiment, the stabilizing protein is an immunoglobulin constant region (Fc) or an albumin protein. In an embodiment, the Fc region is an IgG Fc domain, optionally mouse IgG1 or human IgG2 or IgG4. In another embodiment, the stabilizing polymer is a polyethylene glycol or the like.
[0045] In another embodiment, the soluble fusion molecule comprises the amino acid sequence as shown in SEQ ID NO:2 or 11 or a variant thereof or is encoded by the nucleic acid sequence as shown in SEQ ID NO:1 or 10 or a variant thereof.
[0046] The domains or regions of the soluble fusion molecule of the present disclosure can be linked directly or can comprise a linker between each region, optionally a peptide linker. The peptide linker can be any size provided it does not interfere with the function of the individual linked regions. In one embodiment, the peptide linker is from about 1 to about 15 amino acids in length, more specifically from about 1 to about 10 amino acids, and most specifically from about 1 to about 6 amino acids. Where the soluble fusion molecule is made solely of fused peptides, it may be part of a continuous sequence and as such can be translated as a single polypeptide from a coding sequence that codes for both the at least one extracellular domain and the stabilizing protein.
[0047] In other embodiments, one of skill in the art can appreciate that the fusion molecule can also be formed by linking the at least two protein regions in vitro, for example, using chemical cross-linkers.
[0048] As used herein, the term “protein” or “polypeptide” refers to a sequence of amino acid residues encoded by a nucleic acid molecule. Within the context of the present application, a polypeptide of the disclosure may in one embodiment include various structural forms of the primary protein. For example, a polypeptide of the disclosure may be in the form of acidic or basic salts or in neutral form. In addition, individual amino acid residues may be modified by oxidation or reduction.
[0049] The proteins and polypeptides of the present disclosure may also include truncations, analogs and homologs of the proteins and polypeptides as described herein having substantially the same function as the proteins or polypeptides of the present disclosure, such as the ability to decrease acylated ghrelin.
[0050] Analogs of the proteins described herein, may include, but are not limited to an amino acid sequence containing one or more amino acid substitutions, insertions, and/or deletions. Amino acid substitutions may be of a conserved or non-conserved nature. Conserved amino acid substitutions involve replacing one or more amino acids of the proteins of the disclosure with amino acids of similar charge, size, and/or hydrophobicity characteristics. When only conserved substitutions are made the resulting analog should be functionally equivalent. Non-conserved substitutions involve replacing one or more amino acids of the amino acid sequence with one or more amino acids which possess dissimilar charge, size, and/or hydrophobicity characteristics.
[0051] Conservative substitutions are described in the patent literature, as for example, in U.S. Pat. No. 5,264,558. It is thus expected, for example, that interchange among non-polar aliphatic neutral amino acids, glycine, alanine, proline, valine and isoleucine, would be possible. Likewise, substitutions among the polar aliphatic neutral amino acids, serine, threonine, methionine, asparagine and glutamine could possibly be made. Substitutions among the charged acidic amino acids, aspartic acid and glutamic acid, could probably be made, as could substitutions among the charged basic amino acids, lysine and arginine. Substitutions among the aromatic amino acids, including phenylalanine, histidine, tryptophan and tyrosine would also likely be possible. Other substitutions might well be possible.
[0052] As used herein, the term “variant thereof” means a sequence with at least 75%, 80%, 85%, 90%, 95% or 99% sequence identity to a nucleotide or amino acid sequence of interest.
[0053] The term “sequence identity” as used herein refers to the percentage of sequence identity between two polypeptide sequences or two nucleic acid sequences. To determine the percent identity of two amino acid sequences or of two nucleic acid sequences, the sequences are aligned for optimal comparison purposes (e.g., gaps can be introduced in the sequence of a first amino acid or nucleic acid sequence for optimal alignment with a second amino acid or nucleic acid sequence). The amino acid residues or nucleotides at corresponding amino acid positions or nucleotide positions are then compared. When a position in the first sequence is occupied by the same amino acid residue or nucleotide as the corresponding position in the second sequence, then the molecules are identical at that position. The percent identity between the two sequences is a function of the number of identical positions shared by the sequences (i.e., % identity=number of identical overlapping positions/total number of positions.times.100%). In one embodiment, the two sequences are the same length. The determination of percent identity between two sequences can also be accomplished using a mathematical algorithm. An optional, non-limiting example of a mathematical algorithm utilized for the comparison of two sequences is the algorithm of Karlin and Altschul, 1990, Proc. Natl. Acad. Sci. U.S.A. 87:2264-2268, modified as in Karlin and Altschul, 1993, Proc. Natl. Acad. Sci. U.S.A. 90:5873-5877. Such an algorithm is incorporated into the NBLAST and XBLAST programs of Altschul et al., 1990, J. Mol. Biol. 215:403. BLAST nucleotide searches can be performed with the NBLAST nucleotide program parameters set, e.g., for score=100, wordlength=12 to obtain nucleotide sequences homologous to a nucleic acid molecules of the present disclosure. BLAST protein searches can be performed with the XBLAST program parameters set, e.g., to score-50, wordlength=3 to obtain amino acid sequences homologous to a protein molecule of the present disclosure. To obtain gapped alignments for comparison purposes, Gapped BLAST can be utilized as described in Altschul et al., 1997, Nucleic Acids Res. 25:3389-3402. Alternatively, PSI-BLAST can be used to perform an iterated search, which detects distant relationships between molecules (Id.). When utilizing BLAST, Gapped BLAST, and PSI-Blast programs, the default parameters of the respective programs (e.g., of XBLAST and NBLAST) can be used (see, e.g., the NCBI website). Another optional, non-limiting example of a mathematical algorithm utilized for the comparison of sequences is the algorithm of Myers and Miller, 1988, CABIOS 4:11-17. Such an algorithm is incorporated in the ALIGN program (version 2.0) which is part of the GCG sequence alignment software package. When utilizing the ALIGN program for comparing amino acid sequences, a PAM120 weight residue table, a gap length penalty of 12, and a gap penalty of 4 can be used. The percent identity between two sequences can be determined using techniques similar to those described above, with or without allowing gaps. In calculating percent identity, typically only exact matches are counted.
[0054] As used herein, the term “fragment thereof” refers to a nucleic acid or amino acid sequence comprising up to 3, 5, 10, 15, 25, 50, 100, 250, 500, 1000, 2000 or 3000 contiguous residues of a nucleotide or amino acid sequence of interest.
[0055] Within the context of the present disclosure, a protein of the disclosure may include various structural forms of the primary protein which retain biological activity. For example, a protein of the disclosure may be in the form of acidic or basic salts or in neutral form. In addition, individual amino acid residues may be modified by oxidation or reduction.
[0056] Exemplary methods of making the alterations set forth above are disclosed by Sambrook et al. (Molecular Cloning: A Laboratory Manual, 2nd Ed., Cold Spring Harbor Laboratory Press, 1989).
[0057] Also provided herein is a nucleic acid molecule encoding the soluble fusion molecule of the present disclosure, wherein the molecule optionally comprise a peptide linker joining the various domains of the fusion molecule.
[0058] In another embodiment, the present disclosure provides an isolated nucleic acid molecule encoding the N-terminal domain of GHS-R1a. In one embodiment, the isolated nucleic acid comprises the nucleic acid sequence as shown in SEQ ID NO:3 or 12 or encodes the amino acid sequence as shown in SEQ ID NO:4 or 13. In another embodiment, the present disclosure provides an isolated nucleic acid molecule encoding the extracellular loop 1 of GHS-R1a. In one embodiment, the isolated nucleic acid comprises the nucleic acid sequence as shown in SEQ ID NO:5 or 14 or a variant thereof or encodes the amino acid sequence as shown in SEQ ID NO:6 or 15 or a variant thereof. Further provided herein is an isolated nucleic acid molecule encoding the extracellular loop 2 of GHS-R1a. In one embodiment, the isolated nucleic acid comprises the nucleic acid sequence as shown in SEQ ID NO:7 or 16 or a variant thereof or encodes the amino acid sequence as shown in SEQ ID NO:8or 17 or a variant thereof.
[0059] As used herein, the term “nucleic acid molecule” means a sequence of nucleoside or nucleotide monomers consisting of naturally occurring bases, sugars and intersugar (backbone) linkages. The term also includes modified or substituted sequences comprising non-naturally occurring monomers or portions thereof. The nucleic acid sequences of the present disclosure may be deoxyribonucleic acid sequences (DNA) or ribonucleic acid sequences (RNA) and may include naturally occurring bases including adenine, guanine, cytosine, thymidine and uracil. The sequences may also contain modified bases. Examples of such modified bases include aza and deaza adenine, guanine, cytosine, thymidine and uracil; and xanthine and hypoxanthine.
[0060] The term “isolated nucleic acid sequences” as used herein refers to a nucleic acid substantially free of cellular material or culture medium when produced by recombinant DNA techniques, or chemical precursors, or other chemicals when chemically synthesized. An isolated nucleic acid is also substantially free of sequences, which naturally flank the nucleic acid (i.e. sequences located at the 5′ and 3′ ends of the nucleic acid) from which the nucleic acid is derived. The term “nucleic acid” is intended to include DNA and RNA and can be either double stranded or single stranded, and represents the sense or antisense strand. Further, the term “nucleic acid” includes the complementary nucleic acid sequences.
[0061] The disclosure also provides isolated nucleic acid sequences encoding variants of the CDR sequences and variable region sequences discussed above.
[0062] Variant nucleic acid sequences include nucleic acid sequences that hybridize to the nucleic acid sequences disclosed herein under at least moderately stringent hybridization conditions, or have at least 50%, 60%, 70%, 80%, 90%, 95% or 98% sequence identity to the nucleic acid sequences that encode the amino acid sequences disclosed herein.
[0063] The term “sequence that hybridizes” means a nucleic acid sequence that can hybridize to a nucleic acid sequence disclosed herein under stringent hybridization conditions. Appropriate “stringent hybridization conditions” which promote DNA hybridization are known to those skilled in the art, or may be found in Current Protocols in Molecular Biology, John Wiley & Sons, N.Y. (1989), 6.3.1-6.3.6. The term “stringent hybridization conditions” as used herein means that conditions are selected which promote selective hybridization between two complementary nucleic acid molecules in solution. Hybridization may occur to all or a portion of a nucleic acid sequence molecule. The hybridizing portion is at least 50% the length with respect to one of the polynucleotide sequences encoding a polypeptide. In this regard, the stability of a nucleic acid duplex, or hybrids, is determined by the Tm, which in sodium-containing buffers is a function of the sodium ion concentration, G/C content of labeled nucleic acid, length of nucleic acid probe (l), and temperature (Tm =81.5°C.−16.6(Log 10 [Na+])+0.41(%(G+C)−600/l). Accordingly, the parameters in the wash conditions that determine hybrid stability are sodium ion concentration and temperature. In order to identify molecules that are similar, but not identical, to a known nucleic acid molecule a 1% mismatch may be assumed to result in about a 1°C. decrease in Tm, for example if nucleic acid molecules are sought that have a greater than 95% identity, the final wash will be reduced by 5°C. Based on these considerations stringent hybridization conditions shall be defined as: hybridization at 5× sodium chloride/sodium citrate (SSC)/5× Denhardt's solution/1.0% SDS at Tm (based on the above equation) −5°C., followed by a wash of 0.2×SSC/0.1% SDS at 60°C.
[0064] One example of a nucleic acid modification to prepare an analog is to replace one of the naturally occurring bases (i.e. adenine, guanine, cytosine or thymidine) of the sequence with a modified base such as xanthine, hypoxanthine, 2-aminoadenine, 6-methyl, 2-propyl and other alkyl adenines, 5-halo uracil, 5-halo cytosine, 6-aza uracil, 6-aza cytosine and 6-aza thymine, pseudo uracil, 4-thiouracil, 8-halo adenine, 8-aminoadenine, 8-thiol adenine, 8-thiolalkyl adenines, 8-hydroxyl adenine and other 8-substituted adenines, 8-halo guanines, 8 amino guanine, 8-thiol guanine, 8-thiolalkyl guanines, 8-hydroxyl guanine and other 8-substituted guanines, other aza and deaza uracils, thymidines, cytosines, adenines, or guanines, 5-trifluoromethyl uracil and 5-trifluoro cytosine.
[0065] Another example of a modification is to include modified phosphorous or oxygen heteroatoms in the phosphate backbone, short chain alkyl or cycloalkyl intersugar linkages or short chain heteroatomic or heterocyclic intersugar linkages in the nucleic acid molecules. For example, the nucleic acid sequences may contain phosphorothioates, phosphotriesters, methyl phosphonates, and phosphorodithioates.
[0066] A further example of an analog of a nucleic acid molecule of the disclosure is a peptide nucleic acid (PNA) wherein the deoxyribose (or ribose) phosphate backbone in the DNA (or RNA), is replaced with a polyamide backbone which is similar to that found in peptides (P. E. Nielsen, et al Science 1991, 254, 1497). PNA analogs have been shown to be resistant to degradation by enzymes and to have extended lives in vivo and in vitro. PNAs also bind stronger to a complimentary DNA sequence due to the lack of charge repulsion between the PNA strand and the DNA strand. Other nucleic acid analogs may contain nucleotides containing polymer backbones, cyclic backbones, or acyclic backbones. For example, the nucleotides may have morpholino backbone structures (U.S. Pat. No. 5,034,506). The analogs may also contain groups such as reporter groups, a group for improving the pharmacokinetic or pharmacodynamic properties of nucleic acid sequence.
[0067] A person skilled in the art will appreciate that the proteins of the disclosure may be prepared in any of several ways, including, without limitation, by using recombinant methods.
[0068] Accordingly, the nucleic acid molecules disclosed herein may be incorporated in a known manner into an appropriate expression vector which ensures good expression of the proteins. Possible expression vectors include but are not limited to cosmids, plasmids, or modified viruses (e.g. replication defective retroviruses, adenoviruses and adeno-associated viruses), so long as the vector is compatible with the host cell used. The expression vectors are “suitable for transformation of a host cell”, which means that the expression vectors contain a nucleic acid molecule of the application and regulatory sequences selected on the basis of the host cells to be used for expression, which is operatively linked to the nucleic acid molecule. Operatively linked is intended to mean that the nucleic acid is linked to regulatory sequences in a manner which allows expression of the nucleic acid.
[0069] The disclosure therefore contemplates a recombinant expression vector containing a nucleic acid molecule disclosed herein, and the necessary regulatory sequences for the transcription and translation of the inserted protein-sequence.
[0070] Suitable regulatory sequences may be derived from a variety of sources, including bacterial, fungal, viral, mammalian, or insect genes (For example, see the regulatory sequences described in Goeddel, Gene Expression Technology: Methods in Enzymology 185, Academic Press, San Diego, Calif. (1990)). Selection of appropriate regulatory sequences is dependent on the host cell chosen as discussed below, and may be readily accomplished by one of ordinary skill in the art. Examples of such regulatory sequences include: a transcriptional promoter and enhancer or RNA polymerase binding sequence, a ribosomal binding sequence, including a translation initiation signal. Additionally, depending on the host cell chosen and the vector employed, other sequences, such as an origin of replication, additional DNA restriction sites, enhancers, and sequences conferring inducibility of transcription may be incorporated into the expression vector.
[0071] The recombinant expression vectors of the disclosure may also contain a selectable marker gene which facilitates the selection of host cells transformed or transfected with a recombinant molecule of the application. Examples of selectable marker genes are genes encoding a protein such as G418 and hygromycin which confer resistance to certain drugs, β-galactosidase, chloramphenicol acetyltransferase, firefly luciferase, or an immunoglobulin or portion thereof such as the Fc portion of an immunoglobulin, optionally IgG. Transcription of the selectable marker gene is monitored by changes in the concentration of the selectable marker protein such as β-galactosidase, chloramphenicol acetyltransferase, or firefly luciferase. If the selectable marker gene encodes a protein conferring antibiotic resistance such as neomycin resistance transformant cells can be selected with G418. Cells that have incorporated the selectable marker gene will survive, while the other cells die. This makes it possible to visualize and assay for expression of recombinant expression vectors of the application and in particular to determine the effect of a mutation on expression and phenotype. It will be appreciated that selectable markers can be introduced on a separate vector from the nucleic acid of interest.
[0072] The recombinant expression vectors may also contain genes which encode a fusion moiety which provides increased expression of the recombinant protein; increased solubility of the recombinant protein; and aid in the purification of the target recombinant protein by acting as a ligand in affinity purification. For example, a proteolytic cleavage site may be added to the target recombinant protein to allow separation of the recombinant protein from the fusion moiety subsequent to purification of the fusion protein. Typical fusion expression vectors include pGEX (Amrad Corp., Melbourne, Australia), pMal (New England Biolabs, Beverly, Mass.) and pRIT5 (Pharmacia, Piscataway, N.J.) which fuse glutathione S-transferase (GST), maltose E binding protein, or protein A, respectively, to the recombinant protein.
[0073] Recombinant expression vectors can be introduced into host cells to produce a transformed host cell. The terms “transformed with”, “transfected with”, “transformation” and “transfection” are intended to encompass introduction of nucleic acid (e.g. a vector) into a cell by one of many possible techniques known in the art. The term “transformed host cell” as used herein is intended to also include cells capable of glycosylation that have been transformed with a recombinant expression vector of the invention. Prokaryotic cells can be transformed with nucleic acid by, for example, electroporation or calcium chloride-mediated transformation. For example, nucleic acid can be introduced into mammalian cells via conventional techniques such as calcium phosphate or calcium chloride co-precipitation, DEAE-dextran mediated transfection, lipofectin, electroporation or microinjection. Suitable methods for transforming and transfecting host cells can be found in Sambrook et al. (Molecular Cloning: A Laboratory Manual, 3rd Edition, Cold Spring Harbor Laboratory Press, 2001), and other laboratory textbooks.
[0074] Suitable host cells include a wide variety of eukaryotic host cells and prokaryotic cells. For example, the proteins of the disclosure may be expressed in yeast cells or mammalian cells. Other suitable host cells can be found in Goeddel, Gene Expression Technology: Methods in Enzymology 185, Academic Press, San Diego, Calif. (1991). In addition, the proteins of the disclosure may be expressed in prokaryotic cells, such as Escherichia coli (Zhang et al., Science 303(5656): 371-3 (2004)). In addition, a Pseudomonas -based expression system such as Pseudomonas fluorescens can be used (US Patent Application Publication No. US 2005/0186666, Schneider, Jane C et al.).
[0075] Accordingly, also provided herein is a host cell comprising a nucleic acid molecule of the disclosure.
[0076] Even further provided is a pharmaceutical composition comprising a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure or a host cell of the present disclosure, and a pharmaceutically acceptable carrier.
[0077] The soluble fusion molecule is optionally present in an amount effective for reducing excessive adiposity in a mammal in need thereof.
[0078] The term “effective amount” as used herein means an amount sufficient to achieve the desired result and accordingly will depend on the ingredient and its desired result. Nonetheless, once the desired effect is known, determining the effective amount is within the skill of a person skilled in the art.
[0079] Suitable pharmaceutically acceptable carriers include essentially chemically inert and nontoxic materials that do not interfere with the effectiveness of the biological activity of the pharmaceutical composition. Suitable vehicles are described, for example, in Remington's Pharmaceutical Sciences (Remington's Pharmaceutical Sciences, 20th ed., Mack Publishing Company, Easton, Pa., USA, 2000). Examples of suitable pharmaceutical carriers include, but are not limited to, water, saline solutions, glycerol solutions, ethanol, N-(1(2,3-dioleyloxy)propyl)N,N, N-trimethylammonium chloride (DOTMA), diolesylphosphotidyl-ethanolamine (DOPE), and liposomes. Such compositions contain a therapeutically effective amount of the agent, together with a suitable amount of carrier so as to provide the form for direct administration to the patient.
[0080] In some embodiments, the composition is formulated for administration to a subject such as a human. In particular embodiments, the composition is formulated for intravenous or oral administration. Optionally, the composition is formulated for inhalative, rectal or parenteral administration, including dermal, intradermal, intragastral, intracutan, intravasal, intravenous, intramuscular, intraperitoneal, intranasal, intravaginal, intrabuccal, percutaneous, subcutaneous, sublingual, topical or transdermal administration.
[0081] In another aspect, the present disclosure provides a method of reducing excessive adiposity in an animal comprising administering a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure, or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) to the animal in need thereof. Also provided is a use of a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure, or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) for reducing excessive adiposity in an animal in need thereof. Further provided is a use of a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure, or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) in the manufacture of a medicament for reducing excessive adiposity in an animal in need thereof. Even further provided is a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure, or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) for use in reducing excessive adiposity in an animal in need thereof.
[0082] The phrase “reducing excessive adiposity” as used herein refers to a reduction of at least 1%, 2%, 5%, 10%, 15%, 20% or more in the amount of fat tissue in a treated subject compared to a control that is on the same or similar diet.
[0083] In one embodiment, the present disclosure provide a method of reducing weight gain in an animal comprising administering a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure, or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) to the animal in need thereof. Also provided is use of a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure, or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) for reducing weight gain in an animal in need thereof. Further provided is use of a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure, or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) in the manufacture of a medicament for reducing weight gain in an animal in need thereof. Even further provided is a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure, or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) for use in reducing weight gain in an animal in need thereof.
[0084] The phrase “reducing weight gain” as used herein refers to a reduction of at least 1%, 2%, 5%, 10%, 15%, 20% or more in the mass of a treated subject compared to a control that is on the same or similar diet.
[0085] In another embodiment, the present disclosure provides a method of treating obesity or an obesity-related condition in an animal comprising administering a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure, or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) to the animal in need thereof. Also provided is a use of a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure, or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) for treating obesity or an obesity related condition to an animal in need thereof. Further provided is a use of a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure, or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) in the manufacture of a medicament for treating obesity or an obesity related condition to an animal in need thereof. Even further provided is a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure, or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) for use in treating obesity or an obesity related condition to an animal in need thereof.
[0086] The term “obesity” as used herein refers to a condition in a subject having an accumulation of body fat and includes, without limitation, pre-obesity typically defined as having a body mass index greater than 25, and obesity typically defined having a body mass index greater than 30(often called obese).
[0087] The phrase “treating obesity” includes a reduction of at least 5%, 10%, 15%, 20% or more in weight compared to a non-treated subject on a similar or same diet regimen or a reduction of 5%, 10%, 15%, 20% or more in the ratio of fat mass to lean mass of the subject.
[0088] The term “treating” or “treatment” as used herein and as is well understood in the art, means an approach for obtaining beneficial or desired results, including clinical results. Beneficial or desired clinical results can include, but are not limited to, alleviation or amelioration of one or more symptoms or conditions, diminishment of extent of disease, stabilizing (i.e. not worsening) the state of disease, prevention of disease spread, delaying or slowing of disease progression, amelioration or palliation of the disease state, diminishment of the reoccurrence of disease, and remission (whether partial or total), whether detectable or undetectable. “Treating” and “treatment” can also mean prolonging survival as compared to expected survival if not receiving treatment. “Treating” and “treatment” as used herein also include prophylactic treatment. Treatment methods comprise administering to a subject a therapeutically effective amount of an active agent and optionally consists of a single administration, or alternatively comprises a series of applications. The length of the treatment period depends on a variety of factors, such as the severity of the condition, the age of the patient, the concentration of active ingredient or agent, the activity of the compositions described herein, and/or a combination thereof. It will also be appreciated that the effective dosage of the agent used for the treatment or prophylaxis may increase or decrease over the course of a particular treatment or prophylaxis regime. Changes in dosage may result and become apparent by standard diagnostic assays known in the art. In some instances, chronic administration may be required. For example, the compositions are administered to the subject in an amount and for a duration sufficient to treat the patient.
[0089] In one embodiment, the obesity-related condition is type 2 diabetes, cardiovascular disease or cancer. In an embodiment, the cancer is cancer of the esophagus, breast, endometrium, colorectal or pancreas.
[0090] In another embodiment, the obesity-related condition is high cholesterol, high triglycerides, high blood pressure metabolic syndrome (a combination of high blood sugar, high blood pressure, high triglycerides and high cholesterol) or polycystic ovarian syndrome (PCOS).
[0091] In yet a further embodiment, the present disclosure provides a method of improving glucose tolerance and/or insulin sensitivity in an animal comprising administering a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure, or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) to the animal in need thereof. Also provided is a use of a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure, or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) for improving glucose tolerance and/or insulin sensitivity in an animal in need thereof. Further provided is use of a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure, or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) in the manufacture of a medicament for improving glucose tolerance and/or insulin sensitivity. Even further provided is a soluble fusion molecule of the present disclosure, a nucleic acid molecule of the present disclosure, a host cell of the present disclosure, a pharmaceutical composition of the present disclosure, or an extracellular domain of the growth hormone secretagogue receptor (GHS-R1a) for use in improving glucose tolerance and/or insulin sensitivity in an animal in need thereof.
[0092] The phrase “improving glucose tolerance and/or insulin sensitivity” as used herein refers to an improved metabolic status including reduced blood glucose levels as a result of enhanced insulin secretion and insulin action in the body. This is also exemplified by enhanced glucose uptake or utilization in the insulin-responsible tissues such as muscle, fat and liver.
[0093] The term “subject” or “animal” as used herein includes all members of the animal kingdom, including mammals, and suitably refers to humans. In one embodiment, the animal has Type 2diabetes.
[0094] The term “administering the proteins disclosed herein” includes both the administration of protein as well as the administration of a nucleic acid sequence encoding the protein to an animal or to a cell in vitro or in vivo. The term “administering” also includes the administration of a cell that expresses the antibody or antibody fragment thereof.
[0095] The term “a cell” includes a single cell as well as a plurality or population of cells. Administering to a cell includes administering in vitro (or ex vivo) as well as in vivo.
[0096] The active agents or compositions of the present disclosure may be used alone or in combination with other known agents useful for reducing excessive adiposity or weight gain, for example, for treating obesity or an obesity-related condition in a subject. When used in combination with other agents, it is an embodiment that the compositions or active agents of the present disclosure are administered contemporaneously with those agents. As used herein, “contemporaneous administration” of two substances to a subject means providing each of the two substances so that they are both biologically active in the individual at the same time. The exact details of the administration will depend on the pharmacokinetics of the two substances in the presence of each other, and can include administering the two substances within a few hours of each other, or even administering one substance within 24 hours of administration of the other, if the pharmacokinetics are suitable. Design of suitable dosing regimens is routine for one skilled in the art. In particular embodiments, two substances will be administered substantially simultaneously, i.e., within minutes of each other, or in a single composition that contains both substances. It is a further embodiment of the present disclosure that the composition or active agent of the present disclosure and the other agent(s) is administered to a subject in a non-contemporaneous fashion.
[0097] The dosage of compositions or active agents of the present disclosure can vary depending on many factors such as the pharmacodynamic properties of the composition, the mode of administration, the age, health and weight of the recipient, the nature and extent of the symptoms, the frequency of the treatment and the type of concurrent treatment, if any, and the clearance rate of the composition in the subject to be treated. One of skill in the art can determine the appropriate dosage based on, for example the above factors. Compositions of the present disclosure may be administered initially in a suitable dosage that may be adjusted as required, depending on the clinical response, and may be administered in a single daily dose or the total daily dose may be divided into two, three or four daily doses.
[0098] The above disclosure generally describes the present application. A more complete understanding can be obtained by reference to the following specific examples. These examples are described solely for the purpose of illustration and are not intended to limit the scope of the disclosure. Changes in form and substitution of equivalents are contemplated as circumstances might suggest or render expedient. Although specific terms have been employed herein, such terms are intended in a descriptive sense and not for purposes of limitation.
[0099] The following non-limiting examples are illustrative of the present disclosure:
EXAMPLES
[0100] Depleting circulating ghrelin holds the potential to reduce caloric intake and promote fat energy utilization. As such, mammalian expression plasmid vectors encoding the ligand binding domains of the GHS-R1a were constructed, specifically the N-terminal (Nt), and/or the first, second extracellular domain (EC1, EC2) and were fused with a mouse IgG constant regions (Fc), forming GHSR/Fc ( FIG. 1A ). In vivo expression of these fusion proteins was achieved through plasmid-intramuscular injection and subsequent electroporation in gastrocnemius muscle of mice. The fusion constructs omitted the sequence motif corresponding to the transmembrane domains of the receptor, allowing the production of GHSR/Fc that is secretable.
Results
Validation of GHSR Constructs
[0101] The expression and secretion of the fusion proteins were first examined under in vitro conditions by the transient transfection of the plasmid vectors ( FIG. 1A ) into L6 rat skeletal muscle cell line. At 48 h after transfection, the medium and the cells were harvested separately and extracted proteins were subjected to Western blot analysis using anti-Myc tag antibodies. As shown, the expression of the fusion constructs (Nt-, Nt-EC1, and Nt-EC1-EC2, denoted as GHSR/Fc) was consistently detected in both the cell lysate and culture media whereas the WT/Fc, which contains the transmembrane domains, was only found in the cell lysate (45 kD) ( FIG. 1B ). Similar results were also obtained in the culture media or cell lysate in CHO cells transfected with the fusion constructs ( FIG. 1C ). Immunocytochemistry experiments using anti IgG-Fc antibodies showed that Nt-EC1-EC2(GHSR/Fc), Nt/Fc, EC1/Fc, and WT/Fc were detected in the transfected L6 cells ( FIG. 1D ), suggesting that these fusion proteins can be produced in the mammalian expression system in vitro.
[0000] Effects of in vivo Expression of GHSR/Fc in Mice
[0102] To examine the impact of GHSR gene therapy on energy intake and weight gain, food consumption and body weight was measured in mice injected with the GHSR-based constructs and control mice (injected with the Fc empty vector) fed on a high fat diet (HFD). Mice treated with the GHSR/Fc construct gained significantly less body weight compared to the control animals ( FIG. 2A ). The weight differences began at 30 days post injection (21.0±0.195 g vs 23.8±0.433 g in control, p<0.05), and continued until the termination of the experiment at 54 days post the first injection (23.5±1.36 g vs 29.6±0.434 g in control, p<0.001), ( FIG. 2A ). Mice that received Nt/Fc, Nt-EC1/Fc, or WT/Fc injections all showed a modest reduction in weight gain that did not reach statistical significance. The GHSR/Fc having the N-terminal as well as both extracellular loop 1 and extracellular loop 2 were the focus of the remaining analysis.
[0103] Since ghrelin was previously shown to have a potent orexigenic effect, the daily food and water consumption was examined. As shown in FIG. 2B , there was no difference in food intake between control and GHSR/Fc treated mice. However, treatment with GHSR/Fc increased water intake and urine.
[0104] In vivo expression of the GHSR/Fc was verified by western blot analysis. As shown, western blotting of whole gastrocnemius muscle lysates detected a 55 kDa band corresponding to the GHSR/Fc fusion protein in each of the GHSR/Fc-treated mice ( FIG. 3A ). Furthermore, Western blot analysis of plasma showed the presence of the 55 kDa band in GHSR/Fc treated mice but not in vehicle-injected control mice ( FIG. 3B ). To confirm the ghrelin neutralizing effect of this treatment, the levels of AG and total ghrelin (primarily UAG) were measured in circulation. As shown in FIG. 3C , expression of GHSR/Fc did not alter the levels of total ghrelin ( FIG. 2D 140.9±30.2 pg/ml vs 140.8±37.94 pg/ml in control) but significantly reduced the levels of AG ( FIG. 2D , 1.41±0.160 pg/ml vs 2.25±0.240 pg/ml in control, p<0.05). Finally, to address if reduced AG levels had an effect on the growth hormone pathway, plasma levels of the GH-dependent insulin-like growth factor-1(IGF-1) were examined. No difference was found for IGF-1 levels between the GHSR/Fc treated and control mice ( FIG. 3D ).
Effects of GHSR/Fc on Adipose Tissue
[0105] To determine the source of the reduced weight gain in the treated animals, fat pad and lean tissue (gastrocnemius and soleus muscles) were investigated. Visually, the amount of white adipose tissue (WAT) found in the peritoneum of treated mice was less than control ( FIG. 4A ). This difference was quantified by the weighing of various fat pads. Several fat stores were significantly smaller in the treated mice including retroperitoneal (0.476±0.12 g vs 0.948±0.119 g in control, p<0.001), peri-renal (0.44±0.19 g vs 0.734±0.011 g in control, p<0.05) and inguinal fat pads (0.396±0.067g vs 0.722±0.56 g in control, p<0.05) ( FIG. 4B ). Lean mass was not affected by treatment as determined by the equal gastrocnemius muscle weight (0.131±0.016g vs 0.109±0.011g in control) ( FIG. 4C ).
[0106] Since reduced caloric consumption was not responsible for the reduction in WAT, alterations in WAT mRNA expression in the context of several metabolic genes were examined. Visceral WAT was examined for the adipokine leptin (a hormone that signals in response to fat cell anabolism), hormone sensitive lipase (HSL; an enzyme catalyzing the breakdown of triglycerides to fatty acids) and PPARγ (a nuclear receptor that promotes adipogenesis) mRNA using quantitative RT-PCR. Treated animals had lower levels of leptin gene expression in WAT (0.10±0.14 fold of control, p<0.05) while HSL mRNA (1.76±0.07 fold of control, p<0.05) and PPARγ mRNA (3.91±0.378 fold of control, p<0.05) expression were elevated ( FIG. 4D ). In addition, mRNA levels of adipose-derived proinflammatory cytokines known to be elevated in obesity were examined in WAT. Both interleukin-1 (IL-1) and tumor necrosis factor a (TNFα) were reduced in GHSR/Fc compared to control (2.9±1.6% of control for IL-1, and 15±7% of control for TNFα, p<0.05).
Effect of Neutralizing Ghrelin on Glucose Metabolism
[0107] Ghrelin has been shown to affect glucose homeostasis (Broglio, Arvat et al. 2001). To determine the effect of GHSR/Fc treatment on glucose metabolism, intra-peritoneal glucose tolerance tests (IPGTT) and insulin tolerance tests (ITT) were performed on control and treated mice before and at the end of the study. Treated mice displayed improved glucose tolerance with significantly lower blood glucose at 10 minutes (14.5±1.52 mmol/L vs 18.9±1.48 mmol/L in control, p<0.01) and 20 minutes (10.1±0.968 mmol/L vs 14.2±0.989 mmol/L in control, p<0.05) post glucose injection ( FIG. 5B ). The area under the curve in the IPGTT was also significantly decreased in the treated mice (516±32.2 vs 668±22.1 in control, p<0.05) ( FIG. 5C ). In ITT, area under the glucose curve was lower in treated animals (180±19.1 vs 230±20.3 in control, p<0.05) indicating increased insulin sensitivity ( FIG. 5D and 5E ). These results suggest that reduced circulating AG improves insulin sensitivity and glucose tolerance in mice on a high fat diet.
Discussion
[0108] In this study, an in vivo gene transfer method was used to administer GHSR1a-based fusion proteins as a ‘decoy receptor’ for circulating AG in mice. The fusion constructs were designed to incorporate the extracellular domains of the GHSR1a that interact with the acylated portion of ghrelin, fused with IgG Fc to improve the stability and half-life of the complex in circulation (Soltani, Kumar et al. 2007). Initially, expression and secretion of the construct in vitro was confirmed by plasmid transfection in L6 muscle and CHO cell lines. As expected, the full length WT/Fc was not detected in culture media as it possesses the hydrophobic transmembrane domains that would retain it in the plasma membrane. The expression was further confirmed in both the muscle and plasma from GHSR/Fc plasmid injected animals. To verify that the treatment led to altered ghrelin levels both total (AG+UAG) and acylated (AG) levels were measured in the circulation. While there was no significant difference in the levels of total ghrelin, there was a significant reduction of AG in treated animals. Any differences in AG (5% of total ghrelin in circulation) occurring in the total ghrelin assay would likely be undetectable (Kojima, Hosoda et al. 1999; Ariyasu, Takaya et al. 2001). The lack of difference in the total ghrelin assay confirms the specificity of the GHSR/Fc for binding only AG.
[0109] The impact of neutralizing ghrelin on energy homeostasis was examined by placing animals on a HFD. Thirty days after the HFD feeding, animals treated with GHSR/Fc had gained significantly less weight compared to empty vector treated mice on high fat diet. The reduced weight gain in the GHSR/Fc group was maintained until the end of the study at 74 days post gene transfer with a final weight gain reduction of over 20%. These observations of reduced weight gain and reduced circulating AG in GHSR/Fc mice is in agreement with previous work examining the effects of ghrelin immunoneutralization (Zorrilla, Iwasaki et al. 2006).
[0110] Constructs encoding for the N-terminal region of the GHSR1a (Nt/Fc) or the N-terminal and the first extracellular loop (Nt-EC1/Fc) were also designed. These constructs, while exerting some weight sparing effects, had only a moderate effect compared with GHSR/Fc. The GHSR/Fc was the one construct that incorporated all 3 of the extracellular domains of the GHSR1a (Nt, EC1 and EC2). Without wishing to be bound by theory, of potential importance was the incorporation of both the extracellular loop domains (EC1 and EC2) as these extracellular loops are thought to be the binding sites for AG to the GHS-R1a (Pedretti, Villa et al. 2006).
[0111] Despite the difference in weight gain, no difference was observed throughout the study in food consumed between the GHSR/Fc treatment and control groups. Interestingly, the GHSR/Fc mice showed increased water consumption and urine output. Ghrelin's action on appetite occurs through binding with the GHSR1a in neurons within the arcuate nucleus of the hypothalamus (Cowley, Smith et al. 2003). While peripheral ghrelin administration has been shown to cross the blood brain barrier (BBB) and stimulate appetite (Banks, Tschop et al. 2002), a population of ghrelin-producing neurons also exists within the arcuate nucleus (Kageyama, Kitamura et al. 2008). In the present study, due to the size of the GHSR/Fc protein, it is unlikely that it was able to cross the BBB and neutralize hypothalamic ghrelin. Thus, without wishing to be bound by theory, the present strategy may only be targeting peripheral ghrelin and its actions. In agreement with this study, ghrelin immunoneutralization studies also had no effect on food intake (Zorrilla, Iwasaki et al. 2006). Furthermore, studies that examined both ghrelin and GHSRIa embryonic knockout mice also had no effect on feeding behavior but instead, when challenged with a high fat diet, were more likely to utilize fat as their energy substrate (Wortley, Anderson et al. 2004; Zigman, Nakano et al. 2005). Consistent with these previous observations, reduced fat pads primarily in the peritoneum were found in the present study.
[0112] Given that the food consumption was unchanged in GHSR/Fc-treated mice, the reduced fat mass is likely the consequence of the reduction in AG which affected fat tissue metabolism. Indeed, a recent study indicated that ghrelin acts directly on adipocytes to prevent lipolysis (Davies, Kotokorpi et al. 2009). To determine the effect of reduced circulating ghrelin levels on adipose tissue, the mRNA expression of fat metabolism genes in WAT was measured. Not surprisingly, leptin, which is produced during fat accumulation and adipocyte differentiation (Houseknecht, Baile et al. 1998), was lower in the GHSR/Fc-treated animals. Of particular interest, HSL, a key enzyme in the catabolism of triglycerides to fatty acids (Yeaman 2004), was found to be elevated in the treated animals. This increased lipase expression is indicative of increased mobilization of fatty acids for energy substrate, which supports the finding that the treated animals were protected from adiposity while eating a HFD. This finding is also in good agreement with a previous indirect calorimetry study on ghrelin KO mice that suggested preferential use of fat as their energy substrate (Wortley, Anderson et al. 2004).
[0113] PPARγ mRNA levels were also found to be elevated in the treated animals. While activation of this nuclear receptor typically leads to the differentiation and growth of adipose tissue, some evidence suggests that increased PPARγ may partition fat away from visceral stores (Laplante, Sell et al. 2003). Indeed, the present study shows that the most significant reduction on fat pad weight, in GHSR/Fc-treated mice was in the visceral depots. These findings are supported by other's studies that showed that low dose ghrelin administration caused increased fat pad weight and altered adipocyte gene expression without an effect on feeding in mice (Tsubone, Masaki et al. 2005). Taken together, the present data suggest that reducing circulating AG with GHSR-1a/Fc treatment leads to reduced fat stores and altered adipocyte gene expression.
[0114] Reducing AG with GHSR/Fc treatment significantly improved glucose tolerance and insulin sensitivity in mice on HFD feeding. These findings are in agreement with several studies suggesting that ghrelin promotes glucose homeostasis through inhibiting insulin release from the pancreas (Dezaki, Sone et al. 2006; Dezaki, Sone et al. 2008). Since no differences in circulating insulin levels were observed, the improved glucose clearance may be a consequence of reduced hepatic glucose production in the GHSR/Fc treated animals. This is, at least in part, supported by previous investigation that demonstrated that ghrelin promotes glucose production in hepatocytes(Gauna, Delhanty et al. 2005). Moreover, the improved glucose tolerance may be a secondary effect to the reduced visceral adiposity in GHSR/Fc-mice. It is known that increased adiposity can lead to insulin resistance which is brought on by proinflammatory factors released from inflamed fat stores (Oliver, McGillicuddy et al. 2010).
[0115] To determine the possible involvement of pro-inflammatory cytokines, the mRNA expression of both IL-1 and TNFα was examined in visceral adipose tissue. Both these genes were expressed at significantly lower levels in GHSR/Fc-treated animals, suggesting that improved insulin sensitivity in GHSR/Fc-treated mice may be partially conferred by reduced pro-inflammatory cytokines in these mice. Therefore, the strategy involving neutralization of circulating ghrelin, exemplified by the GHSR/Fc treatment, prevents weight gain and improves glucose tolerance, which may provide beneficial therapies for T2DM.
[0116] The present inventors examined if the GHSR/Fc treatment had any impact on other metabolic hormones. None of the hormones examined (GLP-1, insulin, PYY, pancreatic polypeptide and glucose insulinotropic peptide) were significantly altered by the expression of GHSR/Fc (data not shown). As ghrelin is a known GH secretagogue (Kojima, Hosoda et al. 1999) and GH has effects on glucose metabolism and insulin sensitivity (Moller and Jorgensen 2009), the effects of ghrelin depletion on GH were examined. Since GH varies throughout the day in a pulsatile fashion a more stable measurement of GH levels can be obtained by measuring circulating IGF-1. Interestingly, circulating IGF-1 levels were not affected by ghrelin neutralization and likely were not responsible for the reduced weight and improved glucose parameters. This lack of effect is consistent with a previous report indicating that GH levels are unchanged in GHSR1a KO mice on HFD (Zigman, Nakano et al. 2005).
[0117] In summary, a novel strategy has been developed using secretable GHSR1a-based fusion proteins to neutralize the circulating active ghrelin and hence reduce HFD-induced weight gain. Among those fusion constructs, the GHSR/Fc which contains the Nt, EC1, and EC2 domains of GHSR1a was the most effective in reducing weight gain, improving insulin resistance, and improving glucose tolerance in mice fed with HFD. Of particular benefit, this approach reduced body weight and adiposity, without affecting the appetite and, more particularly, lean mass. The treatment also altered adipose gene expression, exemplified by increased fat catabolism and reduced pro-inflammatory cytokines genes, suggesting a shift to fat usage rather than storage in mice. This yields a secondary beneficial outcome exemplified by improved insulin sensitivity and improved glucose clearance. Thus, GHSR/Fc fusion proteins may have clinical application for the treatment and management of obesity and T2DM.
Methods
Construct Design
[0118] All ghrelin receptor constructs were designed based on the mouse growth hormone secretagogue receptor sequence (Gene ID: 208188). GHSR regions and mouse IgG Fc fragment were produced by PCR amplification. Primers used for amplification of the N-terminal region were (6mNtF) GCG GGG TAC CAT GTG GAA CGC GAC GCC A (SEQ ID NO:19) and (6mNtR) GCG AGT ACT CGC GGG GAA CAG TGG CAG CAG TTC (SEQ ID NO:20), the first extracellular loop (6mEC1F) GCG AAG CTT TTC CAG TTT GTC AGC GAG AGC TGC ACC TAC GCC CCC AGC GAG ACC GTC ACC TGC (SEQ ID NO:21) and (6mEC1R) CGA AGC TTG CAG AGC AGG TCG CCG AAG TTC CAG GGC CGA TAC TGC CAG AGG CGC GCG GGG AAC AGT GGC AGC AGT TC (SEQ ID NO:22), the second extracellular loop (6mEC2F) GCG ACG GAT CCC CGG GAC ACC AAC GAG TGC CGC GCC ACC GAG TTC GCT GTG CGC TCT CCC AGC GAG ACC GTC ACC TGC AAC (SEQ ID NO:23) and (6mEC2R) GCGGGGATCCGTG CCG TTC TCG TGC TCC ACG CCC ACC AGC ACG GCG TAG GTG CAG CTC TCG CTG AC (SEQ ID NO:24), and mouse IgG Fc fragment (mIgGF) GCG AGT ACT TGG CCC AGC GAG ACC GTC ACC TGC AAC (SEQ ID NO:25) and (mIgGR) GCG CTC GAG CAG GGA AGA AGT CTG TTA TCA TGC A (SEQ ID NO:26). Each extracellular domain GHSR PCR product was cleaved with Kpnl and Seal while the mouse IgG Fc fragment was cleaved with Seal and Xhol. This was ligated into the pSecTag2B vector (Invitrogen, ON Canada) at Kpn1 and Xhol using T4 DNA ligase.
[0119] Similar cloning strategy can be utilized for creating fusion molecules comprising the N-terminal, extracellular loop 1 and/or extracellular loop 2 of the mouse or human GHS-R1a.
[0000] In vitro Expression of the Fusion Constructs
[0120] To establish the expression and secretion of GHSR constructs, the rat skeletal muscle cell line L6 and the Chinese hamster ovary CHO cells were transfected with the designed plasmids. 40 μg of cell extract and media were collected using standard methods and run out on 12% SDS PAGE gels. Following the end of experiments, the gastrocnemius muscle was collected and extracted from treated mice to examine the in vivo expression. Proteins were transferred to PVDF membrane and probed using anti-Myc antibody (Millipore) at 1:3000 at 4°C. followed by secondary rabbit ant-mouse HRP at 1:5000 at room temp for 1 hr.
Immunofluorescence Microscopy
[0121] To determine the localization and expression of transfected GHSR proteins, cell lines were immunostained with anti-IgG Fc antibodies which only detect the F chain of the transfected protein. L6 cells were grown on coverslips and were fixed for 1 hr at RT in 4% paraformaldehyde. They were then washed 3 times in PBS followed by 15 minutes of blocking in 5% normal horse serum. Cells were incubated with primary biotinylated anti-mouse Fc in blocking solution for 2 hours at room temperature (RT). Cells were then washed and treated with avidin-conjugated Cy3 in blocking solution for 45 minutes in dark at RT. Coverslips were mounted on slides and visualized on a Zeiss Axioplan II microscope.
[0000] In vivo Expression of GHSR/Fc in Mice
[0122] C57/BI6 mice were purchased from Jackson Laboratories (Bar Harbor, Me., USA). Mice were housed under controlled light (12 h light/12 h dark) and temperature conditions, and had free access to food (normal rodent chow, or high fat-diet where indicated) and water. All procedures were conducted in accordance with the guidelines of the Canadian Council on Animal Care and were approved by the St. Michael's Hospital Animal Care Committee.
[0123] In vivo expression of GHSR/Fc was achieved by intramuscular plasmid injection followed by an electroporation as previously described (Soltani, Kumar et al. 2007). Briefly, a total of 50 μg of plasmid DNA was injected (25 μg per leg) intramuscularly into gastrocnemius of 8 week old male C57/BI6mice and an electrical current was applied using caliper electrodes (BTX, MA) on the muscle as follows; 8 pulses (pulse length 20 ms) with 1 second intervals at 200V/cm. A conductive (aquasonic 100) gel was used to facilitate current delivery. Plasmid injection and electroporation were conducted once weekly for the first 3 weeks of the study course.
Food Intake and Body Weight Measurement:
[0124] High fat diet (Research diets, North Brunswick, N.J., USA, containing 60% of kCal as fat) began on the day of the first DNA injection and continued until the end of the experiment 54 days later. Food consumption was measured by weighing of food basket in each cage every 3 days. Animals from each group were weighed individually every 3 days.
Glucose and Insulin Tolerance Tests:
[0125] Intraperitoneal (ip) glucose and insulin tolerance tests were completed after 54 days of high fat diet. Animals were fasted overnight for 12 hours prior to tests. For the IPGTT, a single bolus injection of glucose at 1.5 mg/kg of mouse weight was administered ip. For the ITT, a single bolus injection of insulin at 0.75 U/kg was injected ip. Tails tips were treated with topical anesthetic (EMLA, ON Canada) and blood samples were drawn from tail vein at 0, 10, 20, 30, and 60 minutes post injection. Blood samples (4-5 μl) were analyzed by the glucose oxidase method using the Bayer Acensia Elite XL glucometer (Bayer, ON Canada).
Fat Tissue Collection
[0126] Post mortem analysis of fat tissues weight was completed by bi-lateral harvesting of fat pads and immediate weighing. The peritoneal fat tissue was snap frozen in liquid nitrogen for later RNA extraction.
Real Time PCR
[0127] Visceral white adipose tissue was collected at the end of the experiment. Total RNA was extracted using the Trizol® (Invitrogen, CA USA) extraction phenol chloroform precipitation method as per manufacturer's protocol. Samples were treated with DNAase (Invitrogen) and cDNA was produced using random hexamers under standard methods. Realtime PCR was conducted on the Bio-Rad CFX instrument (Bio-Rad, CA USA) using primers for leptin (forward: CCAAAACCCTCATCAAGACC (SEQ ID NO:27), reverse: TGTCTCCACCACCGAAACTC (SEQ ID NO:28)), hormone sensitive lipase (forward: TGTCTCCACCACCGAAACTC (SEQ ID NO:29), reverse TCTCCAGTTGAACCAAGCAGGTCA (SEQ ID NO:30)), PPARγ (forward: GGAAAGACAACGGACAAATCAC (SEQ ID NO:31), reverse: ATCCTTGGCCCTCTGAGATG (SEQ ID NO:32)), IL-1 (forward: TGTCTGAAGCAGCTATGGCAA (SEQ ID NO:33, reverse: TGCTGCGAGATTTGAAGCTG (SEQ ID NO:34)) and TNFα (forward: TGATCGGTCCCCAAAGGGAT (SEQ ID NO:35), reverse: TTGCTACGACGTGGGCTAC (SEQ ID NO:36)). Data was analyzed using Bio-Rad CFX manager software and relative expression was determined using the standard curve method with 18S as the normalization gene.
Hormone Assays
[0128] Blood was collected at the end of the experiment in capillary tubes containing EDTA (Sarstedt, PQ) from ad-libitum fed mice. Plasma level of hormones involved in the regulation of energy metabolism was analyzed using the Milliplex hormone assay panel (Millipore, MA) including; active GLP-1, insulin, PYY, pancreatic polypeptide, and GIP (Millipore). Acylated ghrelin and IGF-1 plasma levels were analyzed by enzyme link immunoassays (Cayman chemical, ON and Millipore, MA respectively) and total ghrelin levels were measured using a radioimmunoassay (Phoenix Pharmaceuticals, CA).
Statistical Analysis
[0129] The relative changes in weight gain over time were analyzed using the two-way ANOVA with Bonferroni post test to compare each group to the control group. Multiplex hormone assays analyzing each group were compared with the one-way ANOVA. Time points during IPGTT and ITT were examined by two-way ANOVA. All other comparisons between the control and GHSR/Fc group were analyzed with the student's t-test.
[0130] While the present disclosure has been described with reference to what are presently considered to be the examples, it is to be understood that the disclosure is not limited to the disclosed examples. To the contrary, the disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
[0131] All publications, patents and patent applications are herein 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.
[0000]
TABLE 1
Sequences
mNo6Nt-EC1-EC2-mIgG(nucleic acid)
(SEQ ID NO: 1)
1
atggatgcca tgaagagagg gctctgctgt gtgctgctgc tgtgtggagc agtcttcgtt
61
tcgaacagcg agagcgacac gcgtcggaaa cggatgtgga acgcgacgcc cagcgaggag
121
ccggagccta acgtcacgct ggacctggac tgggacgctt ctcccggcaa cgactcactc
181
tctgacgaac tgctgccact gttccccgcg cgcctctggc agtatcggcc ctggaacttc
241
ggcgacctgc tctgcaaact cttccagttt gtcagcgaga gctgcaccgt gggcgtggag
301
cacgagaacg gcacagatcc ccgggacacc aacgagtgcc gcgccaccga gttcgctgtg
361
cgctctggcg gcggcggacc cagcgagacc gtcacctgca acgttgccca cccggccagc
421
agcaccaagg tggacaagaa aattgtgccc agggattgtg gttgtaagcc ttgcatatgt
481
acagtcccag aagtatcatc tgtcttcatc ttccccccaa agcccaagga tgtgctcacc
541
attactctga ctcctaaggt cacgtgtgtt gtggtagaca tcagcaagga tgatcccgag
601
gtccagttca gctggtttgt agatgatgtg gaggtgcaca cagctcagac gcaaccccgg
661
gaggagcagt tcaacagcac tttccgctca gtcagtgaac ttcccatcat gcaccaggac
721
tggctcaatg gcaaggagtt caaatgcagg gtcaacagtg cagctttccc tgcccccatc
781
gagaaaacca tctccaaaac caaaggcaga ccgaaggctc cacaggtgta caccattcca
841
cctcccaagg agcagatggc caaggataaa gtcagtctga cctgcatgat aacagacttc
901
ttccctgctc gaggagggcc cgaacaaaaa ctcatctcag aagaggatct gaatagcgcc
961
gtcgaccatc atcatcatcat
mNo6 Nt-EC1-EC2-mIgG amino acid sequence
(SEQ ID NO: 2)
MDAMKRGLCCVLLLCGAVFVSNSESDTRRKRMWNATPSEEPEPNVTLDLDWDASPGNDSL
SDELLPLFPARLWQYRPWNFGDLLCKLFQFVSESCTVGVEHENGTDPRDTNECRATEFAV
RSGGGGSRKCCVECPPCPAPPVAGPSVFLFPPKPKDPLMISRTPEVTCVVVDVSHEDPEV
QFNWYVDGVEVHNAKTKPREEQFNSTFRVVSVLTVVHQDWLNGKEYKCKVSNKGLPAPIE
KTISKTKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKT
TPPMLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK--RPRI
PRPRPLAN
Mouse N-Terminal Domain (nucleic acid)
(SEQ ID NO: 3)
1
atgtggaacg cgacgcccag cgaggagccg gagcctaacg tcacgctgga cctggactgg
61
gacgcttctc ccggcaacga ctcactctct gacgaactgc tgccactgtt ccccgcg
Mouse N-Terminal Domain (amino acid)
(SEQ ID NO: 4)
MWNATPSEEPEPNVTLDLDWDASPGNDSLSDELLPLFPA
Mouse EC1 Domain (nucleic acid)
(SEQ ID NO: 5)
1
cgcctctggc agtatcggcc ctggaacttc ggcgacctgc tctgcaaact cttccagttt
61
gtcagcgaga gctgcacc
Mouse EC1 Domain (amino acid)
(SEQ ID NO: 6)
RLWQYRPWNFGDLLCKLFQFVSESCT
Mouse EC2 Domain (nucleic acid)
(SEQ ID NO: 7)
1
gtgggcgtgg agcacgagaa cggcacagat ccccgggaca ccaacgagtg ccgcgccacc
61
gagttcgctg tgcgctct
Mouse EC2 Domain (amino acid)
(SEQ ID NO: 8)
VGVEHENGTDPRDTNECRATEFAVRS
Mouse Ghrelin receptor (nucleic acid)
(SEQ ID NO: 9)
1
atgtggaacg cgacgcccag cgaggagccg gagcctaacg tcacgctgga cctggactgg
61
gacgcttctc ccggcaacga ctcactctct gacgaactgc tgccactgtt ccccgcgccg
121
ctgctggcgg gcgtcactgc cacctgcgtg gcgctcttcg tggtgggcat ctcgggcaac
181
ctgctcacca tgctggtggt gtcccgcttc cgcgagctgc gcaccaccac caacctctac
241
ctatccagca tggccttctc cgatctgctc atcttcctgt gcatgccgct ggacctcgtc
301
cgcctctggc agtatcggcc ctggaacttc ggcgacctgc tctgcaaact cttccagttt
361
gtcagcgaga gctgcaccta cgccacggtc ctcaccatca ccgcgctgag cgtcgagcgc
421
tacttcgcca tctgcttccc gctgcgggcc aaggtggtgg tcaccaaggg ccgtgtgaag
481
ctggtcatcc ttgtcatttg ggccgtggcc ttctgcagcg cggggcccat cttcgtgctg
541
gtgggcgtgg agcacgagaa cggcacagat ccccgggaca ccaacgagtg ccgcgccacc
601
gagttcgctg tgcgctctgg gctgctcacc gtgatggtat gggtgtcgag cgtcttcttc
661
ttcctgccgg tcttctgcct cactgtgctc tacagtctca tcgggaggaa gctgtggcgg
721
aggcgcggcg acgcggcggt gggctcctcg ctcagggacc agaaccacaa acagacagtg
781
aagatgcttg ctgtggtggt gtttgctttc atcctctgct ggctgccctt ccacgtggga
841
agatatctgt tttccaagtc tttcgagcct ggctctctgg agatcgcgca gatcagtcag
901
tactgcaacc tggtgtcctt tgtcctcttc tacctcagcg ctgccatcaa ccccattctc
961
tacaacatca tgtccaagaa gtaccgggtg gccgtgttca aacttctagg atttgaatcc
1021
ttctcccaga gaaagctttc cactctgaag gatgagagtt cccgggcctg gacaaagtcg
1081
agcatcaata catga
Human Fusion molecule (nucleic acid)
(SEQ ID NO: 10)
1
atggatgcca tgaagagagg gctctgctgt gtgctgctgc tgtgtggagc agtcttcgtt
61
tcgaacagcg agagcgacac gcgtcggaaa cggatgtgga acgcgacgcc cagcgaagag
121
ccggggttca acctcacact ggccgacctg gactgggatg cttcccccgg caacgactcg
181
ctgggcgacg agctgctgca gctcttcccc gcgcgcctct ggcagtaccg gccctggaac
241
ttcggcgacc tcctctgcaa actcttccaa ttcgtcagtg agagctgcac cgtcggggtg
301
gagcacgaga acggcaccga cccttgggac accaacgagt gccgccccac cgagtttgcg
361
gtgcgctctg gcggcggcgg atctagaaaa tgttgtgtcg agtgcccacc gtgcccagca
421
ccacctgtgg caggaccgtc agtcttcctc ttccccccaa aacccaagga ccccctcatg
481
atctcccgga cccctgaggt cacgtgcgtg gtggtggacg tgagccacga agaccccgag
541
gtccagttca actggtacgt ggacggcgtg gaggtgcata atgccaagac aaagccacgg
601
gaggagcagt tcaacagcac gttccgtgtg gtcagcgtcc tcaccgttgt gcaccaggac
661
tggctgaacg gcaaggagta caagtgcaag gtctccaaca aaggcctccc agcccccatc
721
gagaaaacca tctccaaaac caaagggcag ccccgagaac cacaggtgta caccctgccc
781
ccatcccggg aggagatgac caagaaccag gtcagcctga cctgcctggt caaaggcttc
841
taccccagcg acatcgccgt ggagtgggag agcaatgggc agccggagaa caactacaag
901
accacacctc ccatgctgga ctccgacggc tccttcttcc tctacagcaa gctcaccgtg
961
gacaagagca ggtggcagca ggggaacgtc ttctcatgct ccgtgatgca tgaggctctg
1021
cacaaccact acacgcagaa gagcctctcc ctgtctccgg gtaaatgata gcggccgcgg
1081
atcccccgac ctcgacctct ggctaat
Human Fusion molecule (amino acid)
(SEQ ID NO: 11)
MDAMKRGLCCVLLLCGAVFVSNSESDTRRKRMWNATPSEEPGFNLTLADLDWDASPGNDS
LGDELLQLFPARLWQYRPWNFGDLLCKLFQFVSESCTVGVEHENGTDPWDTNECRPTEFA
VRSGGGGSRKCCVECPPCPAPPVAGPSVFLEPPKPKDPLMISRTPEVTCVVVDVSHEDPE
VQFNWYVDGVEVHNAKTKPREEQFNSTFRVVSVLTVVHQDWLNGKEYKCKVSNKGLPAPI
EKTISKTKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYK
TTPPMLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK
Human N-Terminal Domain (nucleic acid)
(SEQ ID NO: 12)
1
atgtggaacg cgacgcccag cgaagagccg gggttcaacc tcacactggc cgacctggac
61
tgggatgctt cccccggcaa cgactcgctg ggcgacgagc tgctgcagct cttccccgcg
Human N-Terminal Domain (amino acid)
(SEQ ID NO: 13)
MWNATPSEEPGFNLTLADLDWDASPGNDSLGDELLQLFPA
Human EC1 Domain (nucleic acid)
(SEQ ID NO: 14)
1
cgcctctggc agtaccggcc ctggaacttc ggcgacctcc tctgcaaact cttccaattc
61
gtcagtgaga gctgcacc
Human EC1 Domain (amino acid)
(SEQ ID NO: 15)
RLWQYRPWNFGDLLCKLFQFVSESCT
Human EC2 Domain (nucleic acid)
(SEQ ID NO: 16)
1
gtcggggtgg agcacgagaa cggcaccgac ccttgggaca ccaacgagtg ccgccccacc
61
gagtttgcgg tgcgctct
Human EC2 Domain (amino acid)
(SEQ ID NO: 17)
VGVEHENGTDPWDTNECRPTEFAVRS
Human Ghrelin receptor (nucleic acid)
(SEQ ID NO: 18)
1
atgtggaacg cgacgcccag cgaagagccg gggttcaacc tcacactggc cgacctggac
61
tgggatgctt cccccggcaa cgactcgctg ggcgacgagc tgctgcagct cttccccgcg
121
ccgctgctgg cgggcgtcac agccacctgc gtggcactct tcgtggtggg catcgctggc
181
aacctgctca ccatgctggt ggtgtcgcgc ttccgcgagc tgcgcaccac caccaacctc
241
tacctgtcca gcatggcctt ctccgatctg ctcatcttcc tctgcatgcc cctggacctc
301
gttcgcctct ggcagtaccg gccctggaac ttcggcgacc tcctctgcaa actcttccaa
361
ttcgtcagtg agagctgcac ctacgccacg gtgctcacca tcacagcgct gagcgtcgag
421
cgctacttcg ccatctgctt cccactccgg gccaaggtgg tggtcaccaa ggggcgggtg
481
aagctggtca tcttcgtcat ctgggccgtg gccttctgca gcgccgggcc catcttcgtg
541
ctagtcgggg tggagcacga gaacggcacc gacccttggg acaccaacga gtgccgcccc
601
accgagtttg cggtgcgctc tggactgctc acggtcatgg tgtgggtgtc cagcatcttc
661
ttcttccttc ctgtcttctg tctcacggtc ctctacagtc tcatcggcag gaagctgtgg
721
cggaggaggc gcggcgatgc tgtcgtgggt gcctcgctca gggaccagaa ccacaagcaa
781
accgtgaaaa tgctggctgt agtggtgttt gccttcatcc tctgctggct ccccttccac
841
gtagggcgat atttattttc caaatccttt gagcctggct ccttggagat tgctcagatc
901
agccagtact gcaacctcgt gtcctttgtc ctcttctacc tcagtgctgc catcaacccc
961
attctgtaca acatcatgtc caagaagtac cgggtggcag tgttcagact tctgggattc
1021
gaacccttct cccagagaaa gctctccact ctgaaagatg aaagttctcg ggcctggaca
1081
gaatctagta ttaatacatg a
REFERENCES
[0000]
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Ghrelin is a peptide hormone that binds its receptor, growth hormone secretatgogue receptor 1a (GHS-R1 a, ghrelin receptor), to promote adiposity and obesity in mammals. Ghrelin and its receptor are targets for therapeutic intervention to treat obesity-related disease and cancer. A soluble decoy GHS-R1 a receptor is developed that binds ghrelin in the periphery, preventing ghrelin from binding GHS-R1 on cells, thereby antagonizing ghrelin to treat obesity-related pathological conditions and cancer. GHS-R1 a is a transmembrane protein comprising an N-terminal extracellular domain (Nt), seven transmembrane regions and three extracellular loops (EC1, EC2 and EC3). The Nt, EC1 and EC2 are linked together, in the absence of the transmembrane regions, and fused to a Fc from an immunoglobulin, to create the decoy GHS-R1 a fusion protein, GHSR-Fc. The GHSR-Fc inhibits adiposity and weight gain in mice on a high fat diet (HFD), while the Nt and ECs on their own have no significant effect.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to an internal combustion engine of the type wherein coolant is "boiled off" to make use of the latent heat of evaporation of the coolant and the coolant vapor used as a heat transfer medium, and more specifically to an improved coolant level control arrangement therefor.
2. Description of the Prior Art
In currently used "water cooled" internal combustion engines, the engine coolant (liquid) is forcefully circulated by a water pump through a circuit including the engine coolant jacket and a radiator (usually fan cooled). However, in this type of system a drawback is encountered in that a large volume of water is required to be circulated between the radiator and the coolant jacket in order to remove the required amount of heat. Further, due to the large mass of water inherently required, the warm-up characteristics of the engine are undesirably sluggish. For example, if the temperature difference between the inlet and discharge ports of the coolant jacket is 4 degrees, the amount of heat which 1 Kg of water may effectively remove from the engine under such conditions is 4 Kcal. Accordingly, in the case of an engine having 1800 cc displacement (by way of example) is operated at full throttle, the cooling system is required to remove approximately 4000 Kcal/h. In order to achieve this a flow rate of 167 l/min (viz., 4000-60×1/4) must be produced by the water pump. This of course undesirably consumes a number of horsepower.
In order to overcome this problem it has been proposed to "boil" the coolant and use the vaporized coolant as a heat transfer medium thus taking advantage of the latent heat of evaporation of the coolant. Examples of such arrangements are found in U.S. Pat. No. 1,376,086 issued on Apr. 25, 1921 in the name of Fairman and in European Patent Application Publication No. 0059423 published on Sept. 8, 1982.
However, with such arrangements a problem has been encountered that it is difficult to maintain an adequate level of coolant in the coolant jacket and to avoid either overfilling or underfilling of same especially in automotive applications wherein the attitude of the coolant level changes with change in orientation of the engine and/or vehicle and/or under the influence of centrifugal force when the vehicle traverses a corner or the like. A further problem has been encountered in that upon boiling of the coolant extraordinarily large gas bubbles are sometimes produced which displace the coolant from a particular portion of the coolant jacket permitting the formation of "hot spots" therein. These so called "hot spots" due to their inherent elevated temperature tend to promote the formation of further large gas bubbles which subsequently induces a localized "dry out" within the coolant chamber. This of course leads to knocking and/or thermal damage (e.g. piston seizure).
SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide a coolant level control arrangement for an internal combustion engine of the type wherein the coolant is "boiled off" which obviates overfilling and underfilling of the coolant jacket and which maintains a level which obviates the formation of "hot spots" and "dry outs".
It is a secondary object of the present invention to provide a level control arrangement which permits the amount of coolant in the jacket to be temporarily reduced to predetermined low level during cold engine starts to promote rapid engine warm-up.
In brief, these objects are fullfilled by an embodiment of the invention wherein the coolant level is detected by a plurality of level sensors so that even though the attitude of the coolant surface changes due to a change in orientation of the engine or the like, as long as one of the sensors is immersed in the coolant, the pump which recirculates condensed coolant from a radiator is not energized. An additional low level sensor is used to lower the level of the coolant to a predetermined low level to promote rapid engine warm-up during cold engine starts.
More specifically, the present invention in its broadest sense takes the form of an internal combustion engine which features a coolant jacket into which coolant is introduced in liquid form and discharged in gaseous form, a pump for recirculating liquid coolant from a radiator into which gaseous coolant from the coolant jacket is introduced and condensed to a liquid form, to said coolant jacket, a level sensor disposed in the coolant jacket for detecting the presence of liquid coolant at a predetermined level therein, and a control circuit responsive to the level sensor for energizing the pump when the sensor indicates the level is below the predetermined one.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the arrangement of the present invention will become more clearly appreciated from the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a schematic diagram of an engine system including an embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 an embodiment of the present invention is shown. In this arrangement an internal combustion engine 10 includes a cylinder block 12 on which a cylinder head 14 is detachably secured. The cylinder head and cylinder block include suitable cavities 15-18 which define a coolant jacket 20. In this embodiment the coolant is introduced into the coolant jacket 20 through a port 22 formed in the cylinder block 12 and so as to communicate with a lower level of the coolant jacket 20. Fluidly communicating with a vapor discharge port 24 of the cylinder head 12 is a radiator 26. Disposed in the vapor discharge port 24 is a separator 28 which in this embodiment takes the form of a mesh screen. The separator 28 serves to separate the droplet of liquid and/or foam which tend to be produced by the boiling action, from the vapor per se and minimize unecessary liquid loss from the coolant jacket.
Located suitably adjacent the radiator 26 is a electrically driven fan 30. Disposed in a coolant return conduit 32 is a return pump 34. In this embodiment, the pump is driven by an electric motor 36.
In order to control the level of coolant in the coolant jacket, two level sensors 40, 42 are disposed as shown. Located above the level sensor 40 is a temperature sensor 44 (or alternatively a pressure sensor). The outputs of the level sensors 40, 42 and the temperature sensor 44 are fed to a control circuit 46 or modulator which is suitably connected with a source of EMF upon closure of a switch 46. This switch of course may advantageously be arranged to be simultaneously closed with the ignition switch of the engine (not shown).
A "low" level sensor 50 is disposed in the cylinder block 12 and exposed to the coolant jacket 20 at a predetermined "low" level. The purpose of this sensor will become clear hereinafter.
The level sensors 40, 42 are preferably arranged to produce a signal upon being immersed in coolant. This provides the safeguard should one or more of the sensors (it being noted that the invention is not limited to use of only two sensors) malfunction, the absence of a signal therefrom will cause the energization of the pump motor 36 which overfills the coolant jacket. This guards against an undetected lack of coolant. In the illustrated arrangement the level sensors 40, 42 are arranged on either side of the cylinder head 14 so that should the attitude of the coolant surface change under the influence of cenrifugal force (produced when traversing a curve or the like) or due to the vehicle running on a slanted surface, at least one of the sensors 40, 42 will be immersed in coolant and thus issue a signal. Thus, until both (or all) of the sensors indicate the level having fallen below same, the pump motor 37 is not energized.
The control circuit is arranged to control the operation of the fan 30 in a manner that upon a temperature above a preselected level prevailing in the cylinder head 14 the fan motor is energized to induce a cooling flow of air to pass over the radiator and induce more rapid condensation of the vapor being introduced thereinto. For example, if a temperature of 119 degrees C. is sensed, circuit 46 energizes the fan 30 until the temperature falls to 100 degrees C. (by way of example). Alternatively, if a pressure sensor is used, upon a pressure of 0.9 Kg/cm 2 (corresponding to 119 degrees C.) being sensed as prevailing in the cylinder head the fan be energized until the pressure has fallen to a suitable level.
In this embodiment the control circuit 46 is arranged to, in the event that the temperature in the cylinder head 14 is below a given value indicating a "cold engine", reverse the operation of the pump to pump coolant out of the coolant jacket until the "low" level sensor 50 ceases to output a signal (viz., indicates the coolant level being just below the sensor. This of course markedly reduces the amount of heat which may be removed from the cylinder liners and cylinder head which very rapidly warm up under such conditions. Upon the temperature in the cylinder head 14 being sensed as having risen to a level where normal engine operation can be carried out, the pump motor 36 is energized in a manner to fill the coolant jacket until at least one of the "upper level" sensors 40, 42 is just immersed.
In order to solve the "dry-out" problem it is preferable to arrange the "upper level" sensors 40, 42 to detect a predetermined level which is above that of the structure defining the combustion chamber and associated valving and ports. With this arrangement, other than during warm-up, the cylinder head 14 is securely filled with sufficient coolant to ensure that all of the heated surfaces remain constantly immersed and wetted thereby.
It will be noted that with the present invention the flow rate of coolant is extremely low as compared with the water circulation type. This is due to the fact that the latent heat of evaporation of water is 539 Kcal/Kg. whereby, in order to remove 4000 Kcal of heat from the engine, only 1.23 Kg/min (4000/60/539) is required. Moreover, with the circulation type cooling arrangement, the temperature distribution within the engine is approximately 30 degrees while with the invention less than 6 degrees. Thus, due to the almost uniform temperature of the engine, knocking due to "hot spot" formation is prevented.
It is also possible to provide an engine temperature meter on the instrument panel of the vehicle for indicating the temperature of the engine. As a precautionary measure warning lights 54 can be incorporated in the meter for altering the driver to a possible engine overheat condition.
It will be understood that in accordance with the present invention, if a plurality of "upper level" sensors are used (for example 3), irrespective of the change in attitude of the coolant surface, as long as an adequate amount of coolant is present in the coolant jacket the pump will not be undesirably energized to pump excessive coolant into the cylinder block. Conversely, and more importantly, the arrangement prevents "hot spot" inducing low levels thus securing against any "dry out" phenomenon.
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The level of coolant in the coolant jacket of an "evaporation cooled" engine (wherein the coolant is boiled off in place of being forcefully circulated) is detected by a plurality of level sensors so that even though the attitude of the coolant level changes due to a change in orientation of the engine or the like, as long as one of the sensors is immersed in the coolant, the pump which recirculates condensed coolant from a radiator is not energized. An additional low level sensor is used to lower the level of the coolant to an predetermined low level to promote rapid engine warm-up during cold engine starts.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to personal care appliances. More particularly, the present invention relates to hair setting assemblies for holding and heating hair rollers. The present invention relates even more particularly to a hair setting assembly with a split top lid and a tiltable housing.
2. Description of the Prior Art
Devices for heating hair curlers are well known. A typical hair setting assembly has a housing with a number of electrically heated vertical elements and a number of rollers, generally of different size, disposed on the vertical elements. The rollers are usually provided with a hair gripping outer surface with a thermally insulated portion to allow handling without burning the user's fingers. The inner portion of each roller is usually made of a highly conductive material to facilitate heat transfer from the electrically heated vertical elements to the rollers. A lid, that serves to cover the rollers and retain heat during the warming process, closes the housing. A problem with this conventional configuration is that too much heat is lost when the lid is opened to access the rollers. Also, hair setting assemblies incorporating a steam boiler heating system, as a result of the heating process, tend to collect significant amounts of hot condensed water on the inner surface of the lid. When the lid of such a device is opened during the heating process or thereabouts, which is typical in use, the condensed water tends to spill off the lid and onto the hands of a user and the rollers, potentially burning the user and damaging the rollers. In addition, should a significant amount of water condensation collect on the inner surface of the lid, the condensation can drip off the lid and into the electrical disclosure and wet the insulation disposed therein, thereby creating a shock hazard. These drawbacks are overcome in the hair setting assembly of the present invention.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a hair setting assembly for heating hair rollers used to curl hair.
It is another object of the present invention to provide a hair setting assembly with a housing that is sleek and lightweight.
It is still another object of the present invention to provide a hair setting assembly having a lid that is partitioned into at least two sections for improving heat conservation.
It is yet another object of the present invention to provide a hair setting assembly in which the at least two sections of the lid are configured to collect condensation from the inner surface of the lid and direct the condensation into one or more reservoirs in the housing.
It is a further object of the present invention to provide a hair setting assembly with a tilt adjustable housing to facilitate access to the heated rollers.
These and other objects and advantages of the present invention are achieved by a hair setting assembly of the present invention. The hair setting assembly has a housing with one or more supports for supporting one or more heatable curlers or rollers, a lid divided into at least two sections that are pivotally connected to the housing, and a stand or base.
The at least two sections of the lid are each separately connected to the housing. This aspect allows for selective access to the heated rollers. This selective access helps to reduce the loss of heat and thus improves efficiency. Also, each of the at least two lid sections are configured to collect any condensation that accumulates commonly on the under surface of each section and direct it, when the lid section is opened, into one or more reservoirs disposed in the housing.
In an alternative embodiment, the base is connected to the housing such that the housing can be tilted about an axis in a forward direction through a specified angle. This tilting action facilitates access to the heated rollers and reduces the risk of a user being burned.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is more fully understood by reference to the following detailed description of a preferred embodiment in combination with the drawings identified below.
FIG. 1 is a front view of a hair setting assembly, showing the lid in an opened position in accordance with a preferred embodiment of the present invention;
FIG. 2 is a top view of the hair setting assembly of FIG. 1 ;
FIG. 3 is a front view of the hair setting assembly of FIG. 1 , showing the lid in a closed position;
FIG. 4 is a side view of the hair setting assembly of FIG. 1 ;
FIG. 5 is a side view of the hair setting assembly of FIG. 4 , showing the housing in a tilted position;
FIG. 6 is a top view of the hair setting assembly of FIG. 1 ; and
FIG. 7 is a hair curler for use in the hair setting assembly.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings and, in particular, FIG. 1 , there is shown a hair setting assembly in accordance with a preferred embodiment of the present invention generally represented by reference numeral 1 . The hair setting assembly 1 preferably has a housing 10 , a stand or base 30 , and a split top lid 20 divided into at least two sections. The assembly 1 may also have one or more supports 45 for supporting one or more heatable curlers or rollers 40 . Preferably, lid 20 has a first section 21 and a second section 23 , each pivotally connected to housing 10 .
Housing 10 preferably encloses at least one reservoir (not shown). Preferably, housing 10 also encloses one or more heat conductive supports, shown in FIG. 6 , that has a heating resistor mechanism that is connectable to a power source (not shown). Preferably, the one or more heat conductive supports each sandwich a resistance heater (not shown) and are arranged or tilted on edge to engage rollers 40 directly. Preferably, as shown in FIG. 7 , rollers 40 are forked over the edges of the heat conductive supports. It is noted that other configurations and adaptations may also be used to accomplish the same purposes of the arrangement just described. For example, a single heating plate provided on its top surface with one or more heat conducting elements protruding from the top surface for engagement with rollers 40 may also be used.
Rollers 40 preferably have an inner casing or surface of conductive material and an outer casing or surface of non-conductive material. The inner surface facilitates heat transfer from the conductive elements, as well as heat storage. The outer surface preferably optimizes the amount and effect of heat transferred from the conductive element to enhance the hair curling effect and allow handling by a user without the danger of burning the skin. As clearly shown in FIG. 1 , each roller 40 preferably has a non-conductive cap 42 and a tab 44 to facilitate handling and further reduce the likelihood of the skin being burned.
As discussed above, split top lid 20 is preferably divided into at least two sections, first section 21 and second section 23 . Preferably, first section 21 is the same extent as second section 23 . Lid 20 may also be divided into three or more sections (not shown).
Referring to FIG. 2 , first section 21 preferably is pivotally connected at a first edge 12 of housing 10 by a first connector 13 , and second section 23 preferably is pivotally connected at a second edge 14 of housing 10 by a second connector 15 . Also, should split lid 20 be divided into three or more sections, preferably each additional section would be similarly pivotally connected to a rear edge 18 of housing 10 .
Preferably, first section 21 and second section 23 seal along a mid-line 16 that runs from a front edge 17 of housing 10 to rear edge 18 . First connector 13 and second connector 15 are preferably located at opposing ends of housing 10 . Should lid 20 include three or more sections, preferably each of the three or more sections will cooperate to selectively cover rollers 40 .
Referring to FIGS. 2 through 4 , first section 21 and second section 23 preferably are each configured with one or more channels 25 , 27 , 28 for directing any condensation, accumulating on the under surface of lid 20 , into the at least one reservoir disposed in housing 10 . Preferably, channel 25 is a central channel 25 and channels 27 and 28 are periphery channels. However, other configurations may also be used in order to accomplish different effects and efficiencies.
Thus, the split lid arrangement heretofore preferably described allows for selective access to rollers 40 . This selective access helps to reduce heat loss and improve efficiency.
Referring to FIG. 5 , base 30 preferably is connected to housing 10 such that the housing can be tilted about an axis A in a direction D, through a predetermined angle. Axis A is the axis of the height or vertical extent of the hair setting assembly 1 . This tilting action facilitates access to rollers 40 and reduces the risk of a user being burned. Preferably, housing 10 is configured with a lower portion 31 that is shaped to rest snugly on base 30 . Preferably, lower portion 31 has at least one slidable connector 33 that cooperates with at least two abutments 32 to control the distance through which the connector can slide. Preferably, base 30 has an upper surface configured to receive and engage lower portion 31 via the slidable connector. Lower portion 31 and base 30 can also be configured to provide a variety of different tilt positions. For example, base 30 could be configured with at least one protrusion 34 that cooperates with one or more spring biased structures 35 independently located between the at two abutments of the slidable connector, to provide for the selective tilt positioning of housing 10 relative to base 30 .
The present invention having been thus described with particular reference to the preferred forms thereof, it will be obvious that various changes and modifications may be made therein without departing from the spirit and scope of the present invention as defined herein.
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There is provided a hair setting assembly having a split top lid for improving heat conservation. The assembly also has a tilt adjustable housing that holds a set of hair rollers and encloses an electrical means for heating the rollers.
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